Medium-voltage converter solution with modular multilevel structure and decentralized energy storage integration for high-power wind turbines

IEEE Transactions on Power Electronics

Published On 2021/5/4

As the penetration of renewable energy generation increases, the importance of energy storage systems becomes evident since these systems can contribute for the preservation of the power system stability. Wind turbine owners can also benefit from having energy storage systems as they can increase their revenues. The fast growth of wind turbine power ratings will eventually lead to the requirement of higher voltage levels as well. Proper power electronic converters will be required to drive these systems. Converters with a modular multilevel structure are considered the state-of-the-art solution for high-power applications. These topologies allow for a flexible integration of energy storage systems in both centralized and decentralized ways. This article presents a new converter solution with a modular multilevel structure and decentralized energy storage integration suitable to drive high-power medium-voltage …

Journal

IEEE Transactions on Power Electronics

Published On

2021/5/4

Volume

36

Issue

11

Page

12954-12967

Authors

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Position

Professor at

H-Index(all)

104

H-Index(since 2020)

72

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Power Electronics

Smart Batteries

AI

University Profile Page

Dezso Sera

Dezso Sera

Queensland University of Technology

Position

H-Index(all)

44

H-Index(since 2020)

36

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

photovoltaic systems

power electronics

renewable energy

Tamás Kerekes

Tamás Kerekes

Aalborg Universitet

Position

H-Index(all)

42

H-Index(since 2020)

31

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

power electronics

grid connection

renewable energy

University Profile Page

Laszlo Mathe

Laszlo Mathe

Aalborg Universitet

Position

Associate Professor

H-Index(all)

19

H-Index(since 2020)

14

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Power electronics

University Profile Page

Mattia Ricco

Mattia Ricco

Università degli Studi di Bologna

Position

Assistant Professor -

H-Index(all)

17

H-Index(since 2020)

15

I-10 Index(all)

0

I-10 Index(since 2020)

0

Citation(all)

0

Citation(since 2020)

0

Cited By

0

Research Interests

Power Electronics

EV Chargers

Modular Multilevel Converters

Battery Management Systems

Renewable Energy

University Profile Page

Other Articles from authors

Tamás Kerekes

Tamás Kerekes

Aalborg Universitet

Batteries

Lithium-Ion Supercapacitors and Batteries for Off-Grid PV Applications: Lifetime and Sizing

The intermittent nature of power generation from photovoltaics (PV) requires reliable energy storage solutions. Using the storage system outdoors exposes it to variable temperatures, affecting both its storage capacity and lifespan. Utilizing and optimizing energy storage considering climatic variations and new storage technologies is still a research gap. Therefore, this paper presents a modified sizing algorithm based on the Golden Section Search method, aimed at optimizing the number of cells in an energy storage unit, with a specific focus on the unique conditions of Denmark. The considered energy storage solutions are Lithium-ion capacitors (LiCs) and Lithium-ion batteries (LiBs), which are tested under different temperatures and C-rates rates. The algorithm aims to maximize the number of autonomy cycles—defined as periods during which the system operates independently of the grid, marked by intervals between two consecutive 0% State of Charge (SoC) occurrences. Testing scenarios include dynamic temperature and dynamic load, constant temperature at 25 °C, and constant load, considering irradiation and temperature effects and cell capacity fading over a decade. A comparative analysis reveals that, on average, the LiC storage is sized at 70–80% of the LiB storage across various scenarios. Notably, under a constant-temperature scenario, the degradation rate accelerates, particularly for LiBs. By leveraging the modified Golden Section Search algorithm, this study provides an efficient approach to the sizing problem, optimizing the number of cells and thus offering a potential solution for energy storage in off-grid PV systems.

Tamás Kerekes

Tamás Kerekes

Aalborg Universitet

Green Energy and Intelligent Transportation

Dual-level design for cost-effective sizing and power management of hybrid energy storage in photovoltaic systems

Integration of hybrid energy storage systems (HESS) into photovoltaic (PV) applications has been a hot topic due to their versatility. However, the proper allocation and power management schemes of HESS are challenges under diverse mission profiles. In this paper, a cost-effectiveness-oriented two-level scheme is proposed as a guideline for the PV-HESS system (i.e., PV, Li-ion battery and supercapacitor), to size the system configuration and extend battery lifespan while considering the power ramp-rate constraint. On the first level, a sizing methodology is proposed to balance the self-sufficiency and the energy throughput between the PV system and the grid to achieve the most cost-effectiveness. On the second level, an improved adaptive ramp-rate control strategy is implemented that dynamically distributes the power between the battery and supercapacitor to reduce the battery cycles. The case study presents …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

IEEE Transactions on Industrial Electronics

Health Prediction for Lithium-Ion Batteries Under Unseen Working Conditions

Battery health prediction is significant while challenging for intelligent battery management. This article proposes a general framework for both short-term and long-term predictions of battery health under unseen dynamic loading and temperature conditions using domain-adaptive multitask learning (MTL) with long-term regularization. First, features extracted from partial charging curves are utilized for short-term state of health predictions. Then, the long-term degradation trajectory is directly predicted by recursively using the predicted features within the multitask framework, enhancing the model integrity and lowering the complexity. Then, domain adaptation (DA) is adopted to reduce the discrepancies between different working conditions. Additionally, a long-term regularization is introduced to address the shortcoming that arises when the model is extrapolated recursively for future health predictions. Thus, the short …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

IEEE/ASME Transactions on Mechatronics

Online Sensorless Temperature Estimation of Lithium-Ion Batteries Through Electro-Thermal Coupling

Owing to the nonnegligible impacts of temperature on the safety, performance, and lifespan of lithium-ion batteries, it is essential to regulate battery temperature to an optimal range. Temperature monitoring plays a fundamental role in battery thermal management, yet it is still challenged by limited onboard temperature sensors, particularly in large-scale battery applications. As such, developing sensorless temperature estimation is of paramount importance to acquiring the temperature information of each cell in a battery system. This article proposes an estimation approach to obtain the cell temperature by taking advantage of the electrothermal coupling effect of batteries. An electrothermal coupled model, which captures the interactions between the electrical and the thermal dynamics, is established, parameterized, and experimentally validated. A closed-loop observer is then designed based on this coupled model …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Artificial Intelligence-Based State-of-Health Estimation of Lithium-Ion Batteries

The State of Health (SOH) estimation for automotive batteries is currently assessed with different techniques which may involve long testing procedure or require costly hardware to be implemented. This paper aims at contributing to this domain by exploiting the response of a lead-acid battery with respect to a short-term current profile using an Artificial Neural Network (ANN) classifier for SOH estimation. The method is applicable onboard the vehicle and no additional instrumentation is required on the retained vehicle. The design and validation of a SOH method with a short-term current profile using Artificial Intelligence (AI) in lead-acid batteries, which are commonly used in heavy-duty vehicles for cranking and cabin systems, are presented. The paper validates the considered approach with experimental data, which are representative of actual vehicle operations. In detail, the paper describes the retained …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

arXiv preprint arXiv:2402.07777

Novel Low-Complexity Model Development for Li-ion Cells Using Online Impedance Measurement

Modeling of Li-ion cells is used in battery management systems (BMS) to determine key states such as state-of-charge (SoC), state-of-health (SoH), etc. Accurate models are also useful in developing a cell-level digital-twin that can be used for protection and diagnostics in the BMS. In this paper, a low-complexity model development is proposed based on the equivalent circuit model (ECM) of the Li-ion cells. The proposed approach uses online impedance measurement at discrete frequencies to derive the ECM that matches closely with the results from the electro-impedance spectroscopy (EIS). The proposed method is suitable to be implemented in a microcontroller with low-computational power, typically used in BMS. Practical design guidelines are proposed to ensure fast and accurate model development. Using the proposed method to enhance the functions of a typical automotive BMS is described. Experimental validation is performed using large prismatic cells and small-capacity cylindrical cells. Root-mean-square error (RMSE) of less than 3\% is observed for a wide variation of operating conditions.

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

IEEE Transactions on Industrial Informatics

A Battery Digital Twin From Laboratory Data Using Wavelet Analysis and Neural Networks

Lithium-ion (Li-ion) batteries are the preferred choice for energy storage applications. Li-ion performances degrade with time and usage, leading to a decreased total charge capacity and to an increased internal resistance. In this article, the wavelet analysis is used to filter the voltage and current signals of the battery to estimate the internal complex impedance as a function of state of charge (SoC) and state of health (SoH). The collected data are then used to synthesize a battery digital twin (BDT). This BDT outputs a realistic voltage signal as a function of SoC and SoH inputs. The BDT is based on feedforward neural networks trained to simulate the complex internal impedance and the open-circuit voltage generator. The effectiveness of the proposed method is verified on the dataset from the prognostics data repository of NASA.

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

IEEE Transactions on Industry Applications

Small-Sample-Learning-Based Lithium-Ion Batteries Health Assessment: An Optimized Ensemble Framework

Machine Learning is widely studied in battery state of health (SOH) estimation due to its advantage in establishing the non-linear mapping between measurements and SOH. However, the requirement of a big dataset and the lack of robustness limit the practical application, especially in small sample learning. To tackle these challenges, an optimal ensemble framework called BaggELM (bagging extreme learning machine) is proposed for battery SOH estimation. Specifically, the required dataset is reduced by optimizing the input voltage and the hyperparameters of the BaggELM algorithm. Moreover, a statistical post-processing method is used to aggregate multiple ELMs, and the final estimate is determined by the maximum probability density value. As a result, the effects of random parameterization of ELM and the training data size on SOH estimation are suppressed, thus improving the robustness and accuracy of …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Intelligent Cell Balancing Control for Lithium-Ion Battery Packs

This study introduces a balancing control strategy that employs an Artificial Neural Network (ANN) to ensure State of Charge (SOC) balance across lithium-ion (Li-ion) battery packs, consistent with the framework of smart battery packs. The model targets a battery pack consisting of cells with diverse characteristics, reflecting real-world heterogeneous conditions. A fundamental aspect of this approach is the ability to bypass individual cells optimally. This key feature stops current flow to and from the cell, allowing it to rest and cool off while avoiding charging or discharging cycles. The implementation of ANN enables adaptive and dynamic management of SOC, which is essential for optimizing performance and extending the lifespan of battery packs. The results demonstrate the effectiveness of the proposed ANN-based balancing strategy in SOC balancing, demonstrating its potential as a critical solution in enhancing battery management systems for electric vehicles.

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Grid Impedance Shaping for Grid-Forming Inverters: A Soft Actor-Critic Deep Reinforcement Learning Algorithm

This paper proposed an advanced method for adjusting grid impedance in grid-forming inverters, utilizing the Soft Actor-Critic Deep Reinforcement Learning (SAC-DRL) algorithm. The approach contains a flexible strategy for controlling virtual impedance, supported by an equivalent grid impedance estimator. This facilitates accurate modifications of virtual impedance based on the grid’s X/R ratio and the converter’s power capacity, aiming to optimize power flow and maintain grid stability. A unique feature of this methodology is the division of virtual reactance into two segments: one adhering to standard control protocols and the other designated for precision enhancement via the SAC-DRL method. This strategy introduces a layer of intelligence to the system, strengthening its resilience against fluctuations in grid impedance. Experimental validations, executed on a laboratory setup, verify the robustness of this approach, highlighting its potential to significantly improve intelligent power grid management practices.

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Electric vehicle battery charging strategy

As a key enabler for transportation electrification and a contributor toward the net-zero carbon future, battery plays a pivotal role in determining the energy management performance of electric vehicles. Technical challenges facing the development of advanced automotive battery charging arise from various contradictory objectives, immeasurable internal states, and hard constraints. This chapter presents a critical introduction to the state-of-the-art charging strategies for the electric vehicle battery and their key enabling technologies. Specifically, battery charging solutions for electric vehicles are first classified and discussed. Then, the battery models on which these solutions rest are stated, the related charging frameworks are summarized, and the advantages and drawbacks of the adopted technologies are discussed. Suggestions for overcoming the limitations of the discussed charging strategies are proposed …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Thermal state monitoring of lithium-ion batteries: Progress, challenges, and opportunities

Transportation electrification is a promising solution to meet the ever-rising energy demand and realize sustainable development. Lithium-ion batteries, being the most predominant energy storage devices, directly affect the safety, comfort, driving range, and reliability of many electric mobilities. Nevertheless, thermal-related issues of batteries such as potential thermal runaway, performance degradation at low temperatures, and accelerated aging still hinder the wider adoption of electric mobilities. To ensure safe, efficient, and reliable operations of lithium-ion batteries, monitoring their thermal states is critical to safety protection, performance optimization, as well as prognostics, and health management. Given insufficient onboard temperature sensors and their inability to measure battery internal temperature, accurate and timely temperature estimation is of particular importance to thermal state monitoring. Toward …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Reliability Engineering & System Safety

Predictive health assessment for lithium-ion batteries with probabilistic degradation prediction and accelerating aging detection

Predictive health assessment is of vital importance for smarter battery management to ensure optimal and safe operations and thus make the most use of battery life. This paper proposes a general framework for battery aging prognostics in order to provide the predictions of battery knee, lifetime, state of health degradation, and aging rate variations, as well as the assessment of battery health. Early information is used to predict knee slope and other life-related information via deep multi-task learning, where the convolutional-long-short-term memory-bayesian neural network is proposed. The structure is also used for online state of health and degradation rate predictions for the detection of accelerating aging. The two probabilistic predicted boundaries identify the accelerating aging regions for battery health assessment. To avoid wrong and premature alarms, the empirical model is used for data preprocessing and …

Dezso Sera

Dezso Sera

Queensland University of Technology

Batteries

Lithium-Ion Supercapacitors and Batteries for Off-Grid PV Applications: Lifetime and Sizing

The intermittent nature of power generation from photovoltaics (PV) requires reliable energy storage solutions. Using the storage system outdoors exposes it to variable temperatures, affecting both its storage capacity and lifespan. Utilizing and optimizing energy storage considering climatic variations and new storage technologies is still a research gap. Therefore, this paper presents a modified sizing algorithm based on the Golden Section Search method, aimed at optimizing the number of cells in an energy storage unit, with a specific focus on the unique conditions of Denmark. The considered energy storage solutions are Lithium-ion capacitors (LiCs) and Lithium-ion batteries (LiBs), which are tested under different temperatures and C-rates rates. The algorithm aims to maximize the number of autonomy cycles—defined as periods during which the system operates independently of the grid, marked by intervals between two consecutive 0% State of Charge (SoC) occurrences. Testing scenarios include dynamic temperature and dynamic load, constant temperature at 25 °C, and constant load, considering irradiation and temperature effects and cell capacity fading over a decade. A comparative analysis reveals that, on average, the LiC storage is sized at 70–80% of the LiB storage across various scenarios. Notably, under a constant-temperature scenario, the degradation rate accelerates, particularly for LiBs. By leveraging the modified Golden Section Search algorithm, this study provides an efficient approach to the sizing problem, optimizing the number of cells and thus offering a potential solution for energy storage in off-grid PV systems.

Tamás Kerekes

Tamás Kerekes

Aalborg Universitet

Solar Energy

An adaptive power smoothing approach based on artificial potential field for PV plant with hybrid energy storage system

The increasing quantity of PV installation has brought great challenges to the grid owing to power fluctuations. Hybrid energy storage systems have been an effective solution to smooth out PV output power variations. In order to reduce the required capacity and extend the lifetime of the hybrid energy storage system, a two-stage self-adaptive smoothing approach based on the artificial potential field is proposed to decompose and allocate power among the grid, battery, and supercapacitor dynamically. In the ramp rate control stage, an unsymmetric artificial potential field method is used to regulate the cutoff frequency of a low-pass filter, so as to limit the PV power ramp rate within the prescribed range and allocate the power between the grid and the hybrid energy storage system. In the HESS power distribution stage, a symmetric artificial potential field is adopted to distribute power between the battery and …

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

Fractional-order control techniques for renewable energy and energy-storage-integrated power systems: A review

The worldwide energy revolution has accelerated the utilization of demand-side manageable energy systems such as wind turbines, photovoltaic panels, electric vehicles, and energy storage systems in order to deal with the growing energy crisis and greenhouse emissions. The control system of renewable energy units and energy storage systems has a high effect on their performance and absolutely on the efficiency of the total power network. Classical controllers are based on integer-order differentiation and integration, while the fractional-order controller has tremendous potential to change the order for better modeling and controlling the system. This paper presents a comprehensive review of the energy system of renewable energy units and energy storage devices. Various papers are evaluated, and their methods and results are presented. Moreover, the mathematical fundamentals of the fractional-order method are mentioned, and the various studies are categorized based on different parameters. Various definitions for fractional-order calculus are also explained using their mathematical formula. Different studies and numerical evaluations present appropriate efficiency and accuracy of the fractional-order techniques for estimating, controlling, and improving the performance of energy systems in various operational conditions so that the average error of the fractional-order methods is considerably lower than other ones.

Tamás Kerekes

Tamás Kerekes

Aalborg Universitet

A Control-Oriented Voltage Tracking Design for Grid-Forming Based Modular Multilevel Converter

Modular multilevel converters (MMCs) based on grid-forming control as a converter-driven interface for renewable energy sources are the development trend of the future electronics-dominated power grids. MMC offers outstanding voltage quality without an AC filter, which is very distinct from the AC topology of conventional two-level converters (TLC). However, most literature that studies the grid-forming MMC directly follows the voltage tracking control (VTC) principle of TLC and does not involve the voltage controller specifically for the MMC topology. In this paper, the design of the voltage controller is step-by-step deduced based on the topological properties of MMC. According to the analysis findings, the proportional link of the voltage loop can result in high-frequency oscillation and the proposed VTC with a sole integral link cooperating with inner current-loop control presents excellent dynamic performance …

Dezso Sera

Dezso Sera

Queensland University of Technology

Energies

Sizing of Hybrid Supercapacitors and Lithium-Ion Batteries for Green Hydrogen Production from PV in the Australian Climate

Instead of storing the energy produced by photovoltaic panels in batteries for later use to power electric loads, green hydrogen can also be produced and used in transportation, heating, and as a natural gas alternative. Green hydrogen is produced in a process called electrolysis. Generally, the electrolyser can generate hydrogen from a fluctuating power supply such as renewables. However, due to the startup time of the electrolyser and electrolyser degradation accelerated by multiple shutdowns, an idle mode is required. When in idle mode, the electrolyser uses 10% of the rated electrolyser load. An energy management system (EMS) shall be applied, where a storage technology such as a lithium-ion capacitor or lithium-ion battery is used. This paper uses a state-machine EMS of PV microgrid for green hydrogen production and energy storage to manage the hydrogen production during the morning from solar power and in the night using the stored energy in the energy storage, which is sized for different scenarios using a lithium-ion capacitor and lithium-ion battery. The mission profile and life expectancy of the lithium-ion capacitor and lithium-ion battery are evaluated considering the system’s local irradiance and temperature conditions in the Australian climate. A tradeoff between storage size and cutoffs of hydrogen production as variables of the cost function is evaluated for different scenarios. The lithium-ion capacitor and lithium-ion battery are compared for each tested scenario for an optimum lifetime. It was found that a lithium-ion battery on average is 140% oversized compared to a lithium-ion capacitor, but a lithium-ion capacitor has a …

Laszlo Mathe

Laszlo Mathe

Aalborg Universitet

Flexible and efficient switched string converter

H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF

Remus Teodorescu

Remus Teodorescu

Aalborg Universitet

IEEE Transactions on Vehicular Technology

Battery states monitoring for electric vehicles based on transferred multi-task learning

State/temperature monitoring is one of the key requirements of battery management systems that facilitates efficient and intelligent management to ensure the safe operation of batteries in electrified transportation. This paper proposes an online end-to-end state monitoring method based on transferred multi-task learning. Measurement data is directly used for sharing information generation with the convolutional neural network. Then, the multiple task-specific layers are added for state/temperature monitoring. The transfer learning strategy is designed to improve accuracy further under various application scenarios. Experiments under different working profiles, temperatures, and aging conditions are conducted to evaluate the method, which covers the wide usage ranges in electric vehicles. Comparisons with several benchmarks illustrate the superiority of the proposed method with better accuracy and …

Other articles from IEEE Transactions on Power Electronics journal

Xiaoqiang Guo

Xiaoqiang Guo

Yanshan University

IEEE Transactions on Power Electronics

Passivity-Based Nonsingular Terminal Sliding-Mode Control for LC-Filtered Current Source Converter

It is a big challenge for current source converter (CSC) to ensure the desired tracking performance, robustness, and immunity simultaneously in the presence of resonance caused by the grid-side LC filter and slowly time-varying filter parameters or load disturbances. Aiming at this problem, combining the advantages of passivity-based control (PBC) and nonsingular terminal sliding mode control (NTSMC), a hybrid PBC-NTSMC method is proposed. Based on virtual damping injection and energy dissipation theory, the PBC is firstly designed for the inner loop followed by the construction of the Euler-Lagrange (EL) model. In this way, the resonance suppression is realized and the CSC system is proved to be passive. Furthermore, the NTSMC is combined with PBC to improve the dynamic response, reduce the chattering problem of traditional sliding mode control, and enhance the robustness of the system while …

Henry Chung

Henry Chung

City University of Hong Kong

IEEE Transactions on Power Electronics

Open-Circuit Fault Diagnosis and Fault-Tolerant Control for a Coupled-Inductor-Based Aalborg Inverter

This paper presents an open-circuit fault detection method for a grid-connected neutral-point clamped (NPC) inverter system. Further, a fault-tolerant control method under an open-circuit fault in clamping diodes is proposed. Under the grid-connected condition, it is impossible to identify the location of a faulty switch by the conventional methods which usually use the distortion of outputs because the distortion of the outputs is the same in some fault cases. The proposed fault detection method identifies the location of the faulty switch and the faulty clamping diode of the NPC inverter without any additional hardware or complex calculations. In the case of the clamping diode faults, the NPC inverter can transfer full rated power with sinusoidal currents by the proposed fault-tolerant control. The feasibility of the proposed fault detection and the fault-tolerant control methods for the grid-connected NPC inverter are verified …

2015/12/17

Article Details
Hamzeh Beiranvand

Hamzeh Beiranvand

Christian-Albrechts-Universität zu Kiel

IEEE Transactions on Power Electronics

-Charging Strategy for Lithium-Ion Batteries: Theory, Design, and Validation

This paper introduces a charging strategy for maximizing the instantaneous efficiency ( ) of the lithium-ion (Li-ion) battery and the interfacing power converter. A theory based on the trade-off between several designed Li-ion battery packs and dual-active-bridge (DAB) converter efficiencies is established to find the best compromise. The proposed framework enables Vehicle-to-Everything (V2X) functionality for an electric vehicle providing energy services. Typically, power converters, in particular DAB converters, present low efficiency at light loads and higher values at high power levels. On the other hand, the battery efficiency decreases linearly as the current increases. Therefore, an optimum C-rate could be selected to operate the converter and the battery to minimize the overall losses. Both simulations and experimental results are presented to validate the correctness of the theoretical analyses. The …

Chun Gan

Chun Gan

Huazhong University of Science and Technology

IEEE Transactions on Power Electronics

Cooperative Current Ripple Reduction Strategy for Three-Phase Inverter With Flexible Zero Vector Redistribution

In traditional space vector pulse width modulation (SVPWM) scheme, the duration of zero vector (vector 0, vector 7) is equally divided. On this occasion, the corresponding control freedom is wasted, since the zero vector distribution exerts an influence on the current ripple without affecting the total voltage vector synthesis. Accordingly, this paper proposes a novel cooperative current ripple reduction strategy based on zero vector redistribution for the typical two-level three-phase inverters. In the proposed strategy, the three-phase current ripple condition is classified into 3 cases according to the current ripple change rate and the duty cycle of each phase. In each case, the corresponding optimization method of zero vector distribution is derived and performed, such as only using vector 0, only using vector 7, or flexibly distributing vectors 0 and 7. With the proposed strategy, the three-phase current ripples are reduced …

Wei Hua (花为)

Wei Hua (花为)

Southeast University

IEEE Transactions on Power Electronics

Current Ripple Sampling based Angle Error Compensation for High-speed Permanent Magnet Synchronous Motor Sensorless Control Considering Inductance Saturation

Online parameter identification of high-speed permanent magnet synchronous machine (HSPMSM) has been studied extensively neglecting magnetic saturation. However, at heavy load condition, the difference between apparent inductance and incremental inductance generally exists, which will introduce a potential error in rotor position estimation for sensorless control. Unfortunately, previous research on HSPMSMs has not sufficiently investigated the angle error caused by this saturation. To address this issue, the influence of inductance mismatch on rotor position estimation is analyzed where the inductance error is found proportional to the estimated rotor position error. This analysis provides a potential conversion from apparent inductance identification, which is based on integral armature flux linkage, to a simpler non-integral angle error estimation. Consequently, a current-ripple-sampling (CRS) based …

D Mahinda Vilathgamuwa

D Mahinda Vilathgamuwa

Queensland University of Technology

IEEE Transactions on Power Electronics

A Novel Data-Driven Linear Quadratic Regulator for an Interleaved DC/DC Boost Converter

This article proposes a novel data-driven linear quadratic regulator for an interleaved boost dc/dc converter. The proposed method utilizes policy iteration and a simple fixed weight recurrent neuron network to simultaneously achieve model independent control and autonomous online optimal control gain update. Compared to the existing model-based control approaches, the proposed method is totally model free. In addition, the proposed method updates the neural network without any offline pretraining, which is a key advantage for industrial applications. The experimental results, which are obtained using the Texas Instrument C2000 series digital signal processor, are presented to demonstrate the effectiveness of the proposed method.

Yao Sun

Yao Sun

Central South University

IEEE Transactions on Power Electronics

Frequency-Divided Resistance-Emulating Control of Grid-Connected Voltage Source Rectifiers Under Unbalanced Grids

DC-link voltage pulsation is a technical challenge for grid-connected three-phase voltage source rectifiersunder unbalanced grids. To suppress dc-link voltage ripples arising from unbalanced grids, a frequency-divided resistance-emulating control strategy is proposed in this letter. According to the frequency-divided idea, the dc-link voltage control loop consists of two parts: one dedicated to regulating the average voltage and the other focused on suppressing pulsating voltage. The inner loop is synchronized based on the resistance-emulating approach. The frequency-divided resistance-emulating control offers the following advantages: grid voltage sensors are eliminated, detailed information about circuit parameters is not required, and easy to implement because only one proportional–integral controller, one quasi-proportional–resonantcontroller, and two bandpass filters are used. To sum up, the proposed …

Yonghao Gui

Yonghao Gui

Aalborg Universitet

IEEE Transactions on Power Electronics

Dynamic Power Coupling Analysis of Voltage-Oriented Vector Control in Synchronous Reference Frame

Dynamic Power Coupling Analysis of Voltage-Oriented Vector Control in Synchronous Reference Frame — Aalborg University's Research Portal Skip to main navigation Skip to search Skip to main content Aalborg University's Research Portal Home Aalborg University's Research Portal Logo Dansk English Home Profiles Projects Publications Activities Research units Facilities Press/Media Prizes Datasets Impacts Search by keywords, name or affiliation Dynamic Power Coupling Analysis of Voltage-Oriented Vector Control in Synchronous Reference Frame Zhen Gong, Xiaorong Xie, Chengxi Liu, Yonghao Gui, Filipe Miguel Faria da Silva AAU Energy The Faculty of Engineering and Science Electric Power Systems and Microgrids Modern Power Transmission Grids Research output: Contribution to journal › Journal article › Research › peer-review Overview Original language English Journal IEEE Transactions on …

Shuxin Chen

Shuxin Chen

Nanyang Technological University

IEEE Transactions on Power Electronics

A Front-end Monitoring Method for Coupling Coefficient and Receiver Resonant Frequency in the SS-Compensated Wireless Power Transfer Systems with Unknown Receiver Parameters

In this paper, a front-end monitoring method is proposed to estimate the coupling coefficient and receiver resonant frequency in the series-series (SS) compensated wireless power transfer (WPT) systems. The proposal requires no prior knowledge of the receiver circuit parameters, such as the self-inductance of the coil, compensated capacitor, load resistance, and resonant frequency. Hence, it is suitable for the development of universal wireless charging systems and is immune against parameter tolerances and aging effects. It uses a sensing coil, which is decoupled from the transmitter coil but coupled with the receiver coil, to detect the phase information of the current on the receiver side. Only one zero-crossing sensor is required to detect the voltage information in the sensing coil. Two frequency sweeping processes are included to find the frequency points where the ac output voltage is in phase or out of phase …

Dianxun Xiao

Dianxun Xiao

McMaster University

IEEE Transactions on Power Electronics

Selective Harmonic Elimination and Dynamic Enhancement in Magnetic-Characteristic-Free Sensorless Control of SRM Drives at High Speeds

To address the issues of magnetic parameter dependence and insufficient dynamic performance in high-speed sensorless control of Switched Reluctance Motors (SRMs), this paper proposes a sensorless control scheme based on the Delayed Signal Cancellation Flux Observer (DSCFO) for high-speed SRM drives. This scheme improves the dynamic performance while achieving sensorless control, without the need for magnetic characteristics. Due to the superior filtering efficiency of the DSCFO, the proposed observer eliminates the non-linear terms in the calculated single-phase flux linkage and extracts a pair of orthogonal signals with positional information. Following this, the rotor position and speed information are estimated through the Phase Locked Loop (PLL), enabling sensorless control. Finally, experiments are conducted on a three-phase 5.5 kW 12/8 SRM experimental setup to verify the effectiveness of …

Dianguo XU

Dianguo XU

Harbin Institute of Technology

IEEE Transactions on Power Electronics

Optimization of Current Dynamic Performance and Torque Harmonic for Induction Motor Field-Weakening Control under Hexagon Voltage Extension

The hexagon voltage extension can increase the maximum output torque of the induction motor in field-weakening region. However, nonlinearity voltage and insufficient voltage margin under hexagon voltage operation can lead to torque harmonics and current dynamic performance degradation, respectively. Focusing on these two problems, this paper has quantitatively analyzed the transient voltage vector and the voltage margin requirements when current changes dynamically. And the relation between the torque harmonic and the fundamental output torque is derived in multiple reference frames. Based on the analysis, both the dynamic problem and the harmonic problem under hexagon voltage extension are attributed to the non-adjustable voltage control issue. To solve both problems simultaneously, this paper proposes the optimization structure for multi-state voltage control. The current, the speed, and the …

Marcelo A. Perez

Marcelo A. Perez

Universidad Técnica Federico Santa María

IEEE Transactions on Power Electronics

Common-Mode-Voltage Regulation of Modular Multilevel Converters Through Model Predictive Control

Modular multilevel converters (MMCs) have emerged as an attractive converter topology for renewable energy integration systems. A smooth operation of an MMC depends on the proper regulation of multiple control variables, e.g., phase current, circulating current, capacitor voltage, etc. The model predictive control (MPC) is an excellent candidate for such a scenario since different control objectives can be simultaneously handled in a unified cost function. Although extensive research has been conducted in the literature, a computationally efficient MPC implementation capable of regulating the common-mode voltage (CMV) of the ac-side neutral point of an MMC as a control target has not been properly investigated. This article proposes such an MPC strategy that can flexibly regulate the CMV by incorporating the CMV tracking error into the cost function. The biggest challenge is the dramatically increased number …

Ziheng Xiao

Ziheng Xiao

Hunan University

IEEE Transactions on Power Electronics

A Hybrid Data-driven Power Loss Minimization Method of Dual Active Bridge Converters

Due to the intricate array of control parameters, achieving efficiency optimization for a typical dual active bridge (DAB) prototype becomes a laborious and time-intensive task. Traditional methodologies have revolved around an idealized lossless model of DAB, inevitably leading to a disparity between theoretical ideals and experimental realities. To surmount this challenge, we employ a hybrid data-driven model that seamlessly integrates insights derived from both simulation and experimentation. The disparity between the experimental and simulated models is represented as a residual branch, akin a nonlinear, dissipative impedance. This residual branch contributes to a fraction of power losses and subsequent output voltage/power reduction. The strategic minimization of residual branch emerges as a pivotal step in identifying the optimal control parameters. These optimal control parameters are then subjected to …

Yunwei Ryan Li

Yunwei Ryan Li

University of Alberta

IEEE Transactions on Power Electronics

Efficiency-Oriented Optimized Design and Control of Hybrid FSBB-CLLC Converters with Partial Power Processing Capability

Combining the highly efficient CLLC topology with the exceedingly flexible Four-Switch Buck-Boost (FSBB) topology, this paper introduces a novel hybrid FSBB-CLLC converter incorporating partial power processing (PPP) capability. This hybrid structure utilizes FSBBs to regulate its output voltage by adjusting its duty cycle, handling a small portion of the total power, and providing a fast dynamic response. Meanwhile, the CLLC in the structure operates in a complete resonant state to ensure high system efficiency. By sharing a bridge arm between the FSBB and the CLLC, where one arm from each system serves a similar function, the number of switches utilized is significantly reduced, resulting in higher system efficiency. In addition to the structural improvements, to achieve a higher average system efficiency under different loads, this paper presents an efficiencybased parameter design methodology. Furthermore …

Dr. Muhammad Azam

Dr. Muhammad Azam

University of Veterinary and Animal Sciences

IEEE Transactions on Power Electronics

A Single-Switch Trans-Inverse High Step-Up Semi-Quadratic DC-DC Converter Based on Three-Winding Coupled-Inductor

This paper introduces a new non-isolated singleswitch trans-inverse high step-up semi-quadratic DC-DC converter with low input current ripple for renewable energy generation systems. In the presented topology, a three-winding coupled-inductor combined with a quadratic boost converter to achieve high voltage gains. The advanced features of the suggested structure are its ultra-high voltage conversion ratio, low voltage stress ratio across the switching components, low input current ripple, zero current switching (ZCS) of the semiconductors and also common ground between the input and output sides. Due to the trans-inverse feature in the proposed circuit, higher voltage gains can be achieved without needing large turns’ ratios of the coupled inductor in comparison to the other typical quadratic converters which decreases the conduction power loss. Furthermore, in this topology, the maximum voltage stress …

Nianwen Xiang

Nianwen Xiang

Hefei University of Technology

IEEE Transactions on Power Electronics

An Analytical Carrier Recombination Turn-off Transient Model for High-Voltage IGBTs

High-voltage insulated-gate bipolar transistors (IGBTs) have been extensively used in power electronic systems, such as railway traction inverters, flexible dc transmission systems, and wind turbines, and it is necessary to investigate transient modeling of high-voltage IGBTs. Based on the mechanism of the switching transient, this article proposes a new analytical model for the turn- off process of high-voltage IGBTs. First, considering the large base width of high-voltage IGBTs, the defect of the first-order approximation assumptions used in the existing model is analyzed in detail. Then, by using hyperbolic approximation, an improved solution method is developed for the transient ambipolar diffusion equation that considers the influence of carrier recombination in the base region. Finally, the accuracy of the proposed method is verified by comparing its simulation results with the experiment data obtained under the …

Ruturaj Garnayak

Ruturaj Garnayak

Indian Institute of Technology Kharagpur

IEEE Transactions on Power Electronics

Constant On/Off-Time Digital Current Control and Design Methods in Three-Level Flying-Capacitor Boost Converters for Fast Transient and Voltage Balancing

Constant On/Off-Time Digital Current Control and Design Methods in Three-Level Flying-Capacitor Boost Converters for Fast Transient and Voltage Balancing - NASA/ADS Now on home page ads icon ads Enable full ADS view NASA/ADS Constant On/Off-Time Digital Current Control and Design Methods in Three-Level Flying-Capacitor Boost Converters for Fast Transient and Voltage Balancing Garnayak, Ruturaj ; Kapat, Santanu ; Chakraborty, Chandan Abstract Publication: IEEE Transactions on Power Electronics Pub Date: March 2024 DOI: 10.1109/TPEL.2023.3332100 Bibcode: 2024ITPE...39.2980G full text sources Publisher | © The SAO/NASA Astrophysics Data System adshelp[at]cfa.harvard.edu The ADS is operated by the Smithsonian Astrophysical Observatory under NASA Cooperative Agreement NNX16AC86A NASA logo Smithsonian logo Resources About ADS ADS Help What's New Careers@ADS …

Dongyuan Qiu

Dongyuan Qiu

South China University of Technology

IEEE Transactions on Power Electronics

Modeling and Nonlinear Dynamic Analysis of a Photovoltaic System with Multiple Parallel Branches Based on Simplified Discrete Time Model

The widely used DC distribution system mainly based on new energy generation consists of multiple power electronic converters in series and parallel. The mutual coupling among these converters can lead to complex nonlinear behavior. It is necessary to build a more accurate mathematical model for identifying a more comprehensive nonlinear behavior of this kind of high-order complex system. Therefore, a double-branch parallel photovoltaic system is taken as the research object in this paper, and carries out accurate modeling and nonlinear dynamic analysis of the system. Firstly, the influence of environmental factors on the output characteristic of the system is considered when modeling the photovoltaic generator. Secondly, the simplified discrete-time model is introduced in the dynamic model, which not only simplifies the calculation process, but also ensures the accuracy of the calculation results, and is …

Youhua Shi

Youhua Shi

Waseda University

IEEE Transactions on Power Electronics

A Dual-Output Rectifier-based Self-Powered Interface Circuit for Triboelectric Nanogenerators

Triboelectric nanogenerators (TENGs) offer a cost-effective solution for harvesting energy in Internet of Things (IoT) devices. However, their practical application is limited due to extremely high output voltage and low intrinsic capacitance, alongside the non-self-powered nature of current interface circuits and low transfer efficiency resulting from output voltage asymmetry. Addressing these issues, this letter introduces a dual-output rectifier (DOR)-based interface circuit, innovatively designed to rectify TENG output into two distinct voltage magnitudes, optimizing for energy harvesting and switching generation. The experimental results validate our approach, showing gains of 2.75 and 2.34 times in terms of maximum output power over a full-wave rectifier (FWR)-based design at 2 Hz and 3 Hz, respectively. Furthermore, under identical frequency and load conditions (1MΩ at 2 and 3Hz), the output gains reached 152 …

Tanuj Sen

Tanuj Sen

Princeton University

IEEE Transactions on Power Electronics

Origami Inductor: Foldable 3-D Polyhedron Multiphase Air-Coupled Inductors with Flux Cancellation and Faster Transient

Traditional air-coupled inductors are usually limited to two phases. This article presents the concept of multiphase 3-D polyhedron air-coupled inductors – termed “origami inductors” – formed by folding planar windings on modular surfaces into symmetric 3-D structures, which enables symmetric air-coupling of more than two phases. The air-coupled origami inductors, unlike traditional multiphase coupled inductors, do not need a magnetic core and can operate at high frequencies. Compared to discrete air-core inductors, the origami inductors can be easily transported and assembled and can offer reduced size, smaller current ripple, and faster transient due to dc and ac flux cancellation. Models are developed to quantify the performance benefits of the origami inductor. A tetrahedron-shaped four-phase origami inductor was designed and through FEM simulations, its reduced volume was verified. The origami …