Pub Date : 2025-06-01DOI: 10.23919/CJEE.2025.000137
Rui Xue;Guidong Zhang;Zhong Li
Home energy systems (HESs) are pivotal to Europe's distributed energy transition and to achieving the EU carbon neutrality goals. This study systematically reviews high-impact literature from the past five years, analyzing interdisciplinary progress and key challenges in European HES research. The findings reveal significant regional disparities: photovoltaic systems dominate in Southern Europe, thermal energy storage optimization is prioritized in the North, while Eastern Europe retains its reliance on traditional energy. Policy regulations, economic incentives, and sociocultural factors drive the deployment of HESs beyond the pilot stage. System optimization is increasingly utilizing hybrid energy storage and artificial intelligence-driven controls to enhance economic viability and self-sufficiency. Although HESs contribute to emission reductions and improved air quality, persistent energy equity gaps require targeted policy interventions. Current research limitations include scarce long-term empirical data, limited cross-scale modeling, and inadequate policy synergy assessments. Future studies should prioritize multienergy system integration, digital twin applications, differentiated incentive frameworks, and multidimensional fairness assessments. By synthesizing insights from energy engineering, economics, and environmental sciences, a theoretical framework for the synergistic evolution of the HES technology, policy, and society is proposed. This framework offers a knowledge map for scholars and evidence-based guidance for policymakers and supports the HES transition toward integrated sociotechnical energy systems, providing insights relevant to global energy democratization.
{"title":"Home Energy Systems in Europe: Advancements and Future Directions","authors":"Rui Xue;Guidong Zhang;Zhong Li","doi":"10.23919/CJEE.2025.000137","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000137","url":null,"abstract":"Home energy systems (HESs) are pivotal to Europe's distributed energy transition and to achieving the EU carbon neutrality goals. This study systematically reviews high-impact literature from the past five years, analyzing interdisciplinary progress and key challenges in European HES research. The findings reveal significant regional disparities: photovoltaic systems dominate in Southern Europe, thermal energy storage optimization is prioritized in the North, while Eastern Europe retains its reliance on traditional energy. Policy regulations, economic incentives, and sociocultural factors drive the deployment of HESs beyond the pilot stage. System optimization is increasingly utilizing hybrid energy storage and artificial intelligence-driven controls to enhance economic viability and self-sufficiency. Although HESs contribute to emission reductions and improved air quality, persistent energy equity gaps require targeted policy interventions. Current research limitations include scarce long-term empirical data, limited cross-scale modeling, and inadequate policy synergy assessments. Future studies should prioritize multienergy system integration, digital twin applications, differentiated incentive frameworks, and multidimensional fairness assessments. By synthesizing insights from energy engineering, economics, and environmental sciences, a theoretical framework for the synergistic evolution of the HES technology, policy, and society is proposed. This framework offers a knowledge map for scholars and evidence-based guidance for policymakers and supports the HES transition toward integrated sociotechnical energy systems, providing insights relevant to global energy democratization.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 2","pages":"38-62"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11077901","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144598023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-06-01DOI: 10.23919/CJEE.2025.000135
Ming Cheng;Zhiyuan Xu;Yang Jiang;Chenchen Zhao
An analytical approach is proposed for the cogging torque of a flux-switching permanent magnet machine based on the general air-gap field modulation theory. The modulation process is first investigated, and the cogging torque generation mechanism is analyzed based on the distribution of the air-gap magnetic flux density harmonics. Thus, the relationship between the air-gap field harmonics and the cogging torque is revealed, and the contribution of each harmonic to the cogging torque is calculated using the proposed method. Simultaneously, the characteristics of the cogging torque, including amplitude and frequency, are analyzed. Subsequently, the calculated cogging torque is compared with the simulated torque using finite element analysis. The two results exhibit considerable consistency, confirming the feasibility of the proposed method. Moreover, a prototype experiment is conducted, and the cogging torque is measured to verify the effectiveness of the proposed method.
{"title":"Investigation of Cogging Torque Generation Mechanisms in Flux-switching Permanent Magnet Machines Based on General Air-gap Field Modulation Theory","authors":"Ming Cheng;Zhiyuan Xu;Yang Jiang;Chenchen Zhao","doi":"10.23919/CJEE.2025.000135","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000135","url":null,"abstract":"An analytical approach is proposed for the cogging torque of a flux-switching permanent magnet machine based on the general air-gap field modulation theory. The modulation process is first investigated, and the cogging torque generation mechanism is analyzed based on the distribution of the air-gap magnetic flux density harmonics. Thus, the relationship between the air-gap field harmonics and the cogging torque is revealed, and the contribution of each harmonic to the cogging torque is calculated using the proposed method. Simultaneously, the characteristics of the cogging torque, including amplitude and frequency, are analyzed. Subsequently, the calculated cogging torque is compared with the simulated torque using finite element analysis. The two results exhibit considerable consistency, confirming the feasibility of the proposed method. Moreover, a prototype experiment is conducted, and the cogging torque is measured to verify the effectiveness of the proposed method.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 2","pages":"207-215"},"PeriodicalIF":0.0,"publicationDate":"2025-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=11077891","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144597625","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-11DOI: 10.23919/CJEE.2025.000099
Zhizhong Li;Yuandong Zhang;Samson S. Yu;Guidong Zhang
During wireless charging, misalignments commonly occur in the transmission between the transmitting and receiving pads, including misalignments in the forward, backward, lateral and vertical directions. Unavoidable misalignments can result in changes in system parameters, thus affecting charging performance. A novel diagonally crossed solenoid magnetic coupler (DCSMC) is developed as a solution. The DCSMC integrated into a wireless power transfer (WPT) system with a hybrid topology enables superior misalignment tolerance in the X, Y, Z and XY diagonal directions while maintaining load-independent voltage output characteristics. A simplified parameter design method is developed to optimize the misalignment tolerance performance of a hybrid WPT system in multiple directions. Finally, a hardware prototype of a WPT system is constructed with an operating frequency of 200 kHz and a power of 200 W. The experimental results show that the hybrid WPT system, operating under loads from 40 Ω to 80 Ω, can tolerate misalignments of ±90 mm (40.9%) in both the $X$ and Y axes, maintaining as small as a 5% fluctuation in output voltage. In addition, the WPT system can handle a maximum vertical displacement of +40 mm along the Z-axis and XY-diagonal misalignments of ±40 mm (12.8%).
{"title":"A Hybrid Wireless Power Transfer System with High Misalignment Tolerance Using Diagonal Crossed Solenoid Magnetic Coupler*","authors":"Zhizhong Li;Yuandong Zhang;Samson S. Yu;Guidong Zhang","doi":"10.23919/CJEE.2025.000099","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000099","url":null,"abstract":"During wireless charging, misalignments commonly occur in the transmission between the transmitting and receiving pads, including misalignments in the forward, backward, lateral and vertical directions. Unavoidable misalignments can result in changes in system parameters, thus affecting charging performance. A novel diagonally crossed solenoid magnetic coupler (DCSMC) is developed as a solution. The DCSMC integrated into a wireless power transfer (WPT) system with a hybrid topology enables superior misalignment tolerance in the X, Y, Z and XY diagonal directions while maintaining load-independent voltage output characteristics. A simplified parameter design method is developed to optimize the misalignment tolerance performance of a hybrid WPT system in multiple directions. Finally, a hardware prototype of a WPT system is constructed with an operating frequency of 200 kHz and a power of 200 W. The experimental results show that the hybrid WPT system, operating under loads from 40 Ω to 80 Ω, can tolerate misalignments of ±90 mm (40.9%) in both the <tex>$X$</tex> and Y axes, maintaining as small as a 5% fluctuation in output voltage. In addition, the WPT system can handle a maximum vertical displacement of +40 mm along the Z-axis and XY-diagonal misalignments of ±40 mm (12.8%).","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"138-150"},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10923629","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792904","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-11DOI: 10.23919/CJEE.2025.000108
Xiuyun Zhang;Guidong Zhang;Samson S. Yu
High-performance microprocessors have rapidly evolved and become ubiquitous in modern society. However, their power supply has become a significant factor limiting their overall performance. A power delivery module, known as a voltage regulator module (VRM), is required to provide high voltage, low current, and a fast transient response to meet microprocessor demands. An interleaved parallel-buck converter is suitable for VRM applications. Selecting an appropriate control strategy for the interleaved converter can help achieve high precision and fast response, thereby optimizing performance. First, the operating principles of interleaved parallel converters are analyzed. The relationship between the number of phases and conversion efficiency is also examined. Subsequently, commonly employed control techniques for interleaved converters are reviewed, discussing their respective advantages and limitations, along with an analysis of their suitability for phase-shedding strategies. A phase-shedding technique for interleaved converters is then introduced. Finally, the shortcomings of current control approaches for interleaved buck converters are outlined, and potential future research directions are suggested. These insights aim to enhance control performance and advance practical engineering applications.
{"title":"Review of Control Techniques for Interleaved Buck Converters: Control Strategies, Efficiency Optimization and Phase Shedding*","authors":"Xiuyun Zhang;Guidong Zhang;Samson S. Yu","doi":"10.23919/CJEE.2025.000108","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000108","url":null,"abstract":"High-performance microprocessors have rapidly evolved and become ubiquitous in modern society. However, their power supply has become a significant factor limiting their overall performance. A power delivery module, known as a voltage regulator module (VRM), is required to provide high voltage, low current, and a fast transient response to meet microprocessor demands. An interleaved parallel-buck converter is suitable for VRM applications. Selecting an appropriate control strategy for the interleaved converter can help achieve high precision and fast response, thereby optimizing performance. First, the operating principles of interleaved parallel converters are analyzed. The relationship between the number of phases and conversion efficiency is also examined. Subsequently, commonly employed control techniques for interleaved converters are reviewed, discussing their respective advantages and limitations, along with an analysis of their suitability for phase-shedding strategies. A phase-shedding technique for interleaved converters is then introduced. Finally, the shortcomings of current control approaches for interleaved buck converters are outlined, and potential future research directions are suggested. These insights aim to enhance control performance and advance practical engineering applications.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"40-58"},"PeriodicalIF":0.0,"publicationDate":"2025-03-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10923626","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792953","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-06DOI: 10.23919/CJEE.2025.000129
Samson S. Yu;Md. Siddikur Rahman;Guidong Zhang;Sheikh Tanzim Meraj;Hieu Trinh
In the contemporary energy landscape, the transition from traditional power grids to smart grids is being increasingly facilitated by the real-time monitoring, protection, and control capabilities provided by wide-area measurement systems. The core of this evolution is the synchrophasor technology, which provides time-synchronized phasor measurements (an essential component for the successful implementation of smart grids). These phasor measurements are acquired through advanced, rapid, time-stamped devices known as phasor measurement units (PMUs), which play a pivotal role in enhancing grid reliability and efficiency. PMUs providehigh accuracy and precision in capturing electric phasors. This advancement has significantly contributed to the reliability of power systems. The data obtained from the PMUs can be applied across a diverse range of contexts and categorized according to their time criticality requirements. Furthermore, the applications can be classified according to their operational foci. A comprehensive review of the pivotal role of PMUs within the context of smart grid systems is presented. It systematically addresses the following key areas: the significance of real-time monitoring and control facilitated by PMUs in smart grids, contribution of PMUs to enhanced situational awareness, utilization of PMU data for state estimation applications, and critical function of PMUs in accurately identifying faults and their locations within the smart grid infrastructure. Additionally, PMU data management is explored. The focus here is on the processes of data acquisition and transmission enabled by PMUs in smart grids and the relevant communication technologies and protocols employed. This study aims to highlight the integral role of PMUs in optimizing the performance and reliability of smart grid networks.
{"title":"Comprehensive Review of PMU Applications in Smart Grid: Enhancing Grid Reliability and Efficiency","authors":"Samson S. Yu;Md. Siddikur Rahman;Guidong Zhang;Sheikh Tanzim Meraj;Hieu Trinh","doi":"10.23919/CJEE.2025.000129","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000129","url":null,"abstract":"In the contemporary energy landscape, the transition from traditional power grids to smart grids is being increasingly facilitated by the real-time monitoring, protection, and control capabilities provided by wide-area measurement systems. The core of this evolution is the synchrophasor technology, which provides time-synchronized phasor measurements (an essential component for the successful implementation of smart grids). These phasor measurements are acquired through advanced, rapid, time-stamped devices known as phasor measurement units (PMUs), which play a pivotal role in enhancing grid reliability and efficiency. PMUs providehigh accuracy and precision in capturing electric phasors. This advancement has significantly contributed to the reliability of power systems. The data obtained from the PMUs can be applied across a diverse range of contexts and categorized according to their time criticality requirements. Furthermore, the applications can be classified according to their operational foci. A comprehensive review of the pivotal role of PMUs within the context of smart grid systems is presented. It systematically addresses the following key areas: the significance of real-time monitoring and control facilitated by PMUs in smart grids, contribution of PMUs to enhanced situational awareness, utilization of PMU data for state estimation applications, and critical function of PMUs in accurately identifying faults and their locations within the smart grid infrastructure. Additionally, PMU data management is explored. The focus here is on the processes of data acquisition and transmission enabled by PMUs in smart grids and the relevant communication technologies and protocols employed. This study aims to highlight the integral role of PMUs in optimizing the performance and reliability of smart grid networks.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 4","pages":"19-59"},"PeriodicalIF":3.5,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10989599","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145915611","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.23919/CJEE.2025.000101
Vladimir Dmitrievskii;Aleksey Paramonov;Vadim Kazakbaev;Vladimir Prakht
Line-start permanent-magnet synchronous motors (LSPMSMs) are energy-efficient alternatives to induction motors. However, LSPMSMs are associated with synchronization difficulties when starting in cases of high inertia, heavy loads, or supply-voltage sags. Models with lumped parameters and parameter identification are used to study the starting processes. A novel approach for identifying the parameters of an LSPMSM is presented based on reduced experimental data that only include the recording of oscillograms of instantaneous currents and voltages when starting the LSPMSM from an idle state. The parameters of the lumped model are determined using the Nelder-Mead method while minimizing the root-mean-square error between the experimental and calculated waveforms. Multiple starts under different initial conditions are considered owing to uncertain initial conditions, and the initial conditions are excluded from the parameter space of the objective function. The proposed method is used to identify the parameters of a commercially available 0.55 kW, 1 500 r/min LSPMSM sample. The results obtained by modeling the starting processes of the LSPMSM using the identified parameters are similar to the experimental results.
{"title":"Computer-aided Experimental Identification of Line-start Permanent-magnet Synchronous-motor Parameters Based on Dynamic Electrical Processes*","authors":"Vladimir Dmitrievskii;Aleksey Paramonov;Vadim Kazakbaev;Vladimir Prakht","doi":"10.23919/CJEE.2025.000101","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000101","url":null,"abstract":"Line-start permanent-magnet synchronous motors (LSPMSMs) are energy-efficient alternatives to induction motors. However, LSPMSMs are associated with synchronization difficulties when starting in cases of high inertia, heavy loads, or supply-voltage sags. Models with lumped parameters and parameter identification are used to study the starting processes. A novel approach for identifying the parameters of an LSPMSM is presented based on reduced experimental data that only include the recording of oscillograms of instantaneous currents and voltages when starting the LSPMSM from an idle state. The parameters of the lumped model are determined using the Nelder-Mead method while minimizing the root-mean-square error between the experimental and calculated waveforms. Multiple starts under different initial conditions are considered owing to uncertain initial conditions, and the initial conditions are excluded from the parameter space of the objective function. The proposed method is used to identify the parameters of a commercially available 0.55 kW, 1 500 r/min LSPMSM sample. The results obtained by modeling the starting processes of the LSPMSM using the identified parameters are similar to the experimental results.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"206-217"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10955300","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792920","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.23919/CJEE.2025.000106
Hassen Smail;Mostafa Kamel Smail;Abdelhak Goudjil
Variable-speed generators (VSG) offer numerous benefits over fixed-speed generators. These advantages include significant fuel savings, reduced noise emissions, and extended engine lifespan. However, VSGs have a major drawback: their high manufacturing cost owing to the expensive permanent-magnet generators (PMGs) commonly used in these generators, as well as the large size of the power electronics section, which has the same power rating as the generator itself. A solution to reduce the initial investment cost by introducing a two-regime generator (TRG) is proposed. The first mode operates at a constant speed for loads exceeding 50%, without the need for a converter. The second mode operates at variable speeds for loads below 50% using a converter that reduces its power by 50%, thus decreasing the investment cost. Additionally, the cost can be further reduced by replacing the PMG with a brushless synchronous generator. The controller employed in this study is a two-loop proportional-integral-derivative controller that exhibits favorable dynamics and compensates for dead times and parameter variations. TRG have shown a significant reduction in cost compared to VSG while retaining the advantages of the latter.
{"title":"Efficiency Enhancement and Cost Reduction through Speed Optimization of Two-regime Generator Set with Three-stage Synchronous Alternator","authors":"Hassen Smail;Mostafa Kamel Smail;Abdelhak Goudjil","doi":"10.23919/CJEE.2025.000106","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000106","url":null,"abstract":"Variable-speed generators (VSG) offer numerous benefits over fixed-speed generators. These advantages include significant fuel savings, reduced noise emissions, and extended engine lifespan. However, VSGs have a major drawback: their high manufacturing cost owing to the expensive permanent-magnet generators (PMGs) commonly used in these generators, as well as the large size of the power electronics section, which has the same power rating as the generator itself. A solution to reduce the initial investment cost by introducing a two-regime generator (TRG) is proposed. The first mode operates at a constant speed for loads exceeding 50%, without the need for a converter. The second mode operates at variable speeds for loads below 50% using a converter that reduces its power by 50%, thus decreasing the investment cost. Additionally, the cost can be further reduced by replacing the PMG with a brushless synchronous generator. The controller employed in this study is a two-loop proportional-integral-derivative controller that exhibits favorable dynamics and compensates for dead times and parameter variations. TRG have shown a significant reduction in cost compared to VSG while retaining the advantages of the latter.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"194-205"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10955297","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Diode rectifier unit (DRU)-based high-voltage direct current (HVDC) transmission systems are effective in achieving the stable and economical operation of offshore wind-power generation. Considering the uncontrollable characteristics of DRUs, a grid-forming (GFM) strategy for wind-turbine converters is necessary to support offshore AC voltage and frequency. However, the active power-synchronization control in traditional GFM converters is unsuitable for DRU-based GFM converters. Thus, the stability issue for DRU-based HVDC systems involving DRU-based GFM and grid-following (GFL) converters has not yet been addressed. To solve these issues, this study begins with the characteristics of a DRU-based HVDC system and presents a control scheme for DRU-based GFM converters for power synchronization. Subsequently, the dq-frame impedance model of the DRU-based GFM converter is proposed for the stability analysis of the entire HVDC system. Finally, a simulation platform is built to verify the model accuracy and system stability.
{"title":"Control, Modeling and Stability Analysis of DRU-based Grid-forming Converter*","authors":"Wencong Wu;Minzhi Wang;Liang Tu;Haiqing Cai;Guanglei Yan;Xiaohui Qu;Haohan Gu;Wei Chen","doi":"10.23919/CJEE.2025.000100","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000100","url":null,"abstract":"Diode rectifier unit (DRU)-based high-voltage direct current (HVDC) transmission systems are effective in achieving the stable and economical operation of offshore wind-power generation. Considering the uncontrollable characteristics of DRUs, a grid-forming (GFM) strategy for wind-turbine converters is necessary to support offshore AC voltage and frequency. However, the active power-synchronization control in traditional GFM converters is unsuitable for DRU-based GFM converters. Thus, the stability issue for DRU-based HVDC systems involving DRU-based GFM and grid-following (GFL) converters has not yet been addressed. To solve these issues, this study begins with the characteristics of a DRU-based HVDC system and presents a control scheme for DRU-based GFM converters for power synchronization. Subsequently, the dq-frame impedance model of the DRU-based GFM converter is proposed for the stability analysis of the entire HVDC system. Finally, a simulation platform is built to verify the model accuracy and system stability.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"83-92"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10955306","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792910","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-03-01DOI: 10.23919/CJEE.2025.000096
Shaoxiong Nie;Jiahua Zhang;Wenxun Xiao;Guiping Du
Energy-harvesting technologies enable the extraction of energy from environmental sources characterized by extremely low voltages. A high-gain DC-DC converter with an ultralow input voltage is necessary for voltage conversion to supply energy to sensors, batteries, and other devices. However, existing ultra-low-voltage boost converters typically exhibit limited output power, posing significant challenges in fully utilizing the available energy, particularly in applications such as high-voltage direct-current (HVDC) transmission line voltage-difference energy harvesting. To maximize the harvested energy, this study proposes a high-gain DC-DC converter designed for operation with ultra-low input voltage. The proposed converter utilizes a hybrid inductor-switch-capacitor (LSC) boost network, which offers advantages such as high voltage gain, increased output power, and straightforward control mechanisms. Experimental findings indicate that the converter achieves output power ranging from 10 to 210 mW with input voltages between 100 and 300 mV, delivering an output voltage of 5 V. This performance surpasses that of existing ultra-low-voltage boosting methods, providing a more effective solution for energy-harvesting applications.
{"title":"High-gain DC-DC Converter with Ultra-low Input Voltage*","authors":"Shaoxiong Nie;Jiahua Zhang;Wenxun Xiao;Guiping Du","doi":"10.23919/CJEE.2025.000096","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000096","url":null,"abstract":"Energy-harvesting technologies enable the extraction of energy from environmental sources characterized by extremely low voltages. A high-gain DC-DC converter with an ultralow input voltage is necessary for voltage conversion to supply energy to sensors, batteries, and other devices. However, existing ultra-low-voltage boost converters typically exhibit limited output power, posing significant challenges in fully utilizing the available energy, particularly in applications such as high-voltage direct-current (HVDC) transmission line voltage-difference energy harvesting. To maximize the harvested energy, this study proposes a high-gain DC-DC converter designed for operation with ultra-low input voltage. The proposed converter utilizes a hybrid inductor-switch-capacitor (LSC) boost network, which offers advantages such as high voltage gain, increased output power, and straightforward control mechanisms. Experimental findings indicate that the converter achieves output power ranging from 10 to 210 mW with input voltages between 100 and 300 mV, delivering an output voltage of 5 V. This performance surpasses that of existing ultra-low-voltage boosting methods, providing a more effective solution for energy-harvesting applications.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"74-82"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10955347","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792911","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In addressing voltage overruns and line losses in distribution networks with a high percentage of distributed photovoltaic (PV) connections, traditional on-load regulator transformers can achieve only fixed-step voltage regulation and have a limited switching lifespan. Consequently, a discrete-continuous two-layer optimization methodology for distribution networks, which accounts for power-converter-embedded hybrid on-load regulator transformers, has been proposed to adapt to rapid stochastic fluctuations associated with distribution networks having a high percentage of PV access. In the discrete layer, the mechanical ratio is employed as the decision variable at each moment. In the continuous layer, the power electronic converter ratio, STATCOM compensation capacity, and energy storage charging and discharging power are utilized as decision variables at each moment. A composite optimal allocation model is established with an integrated objective function comprising the PV consumption rate, operating costs, and line losses, while simultaneously ensuring that the voltage at each node remains within the prescribed limits. Based on this model, an improved particle swarm algorithm is employed to determine the optimal configuration. Finally, the efficacy of the proposed method is validated through enhancements of the IEEE 33 node system example.
{"title":"A Discrete-continuous Two-layer Optimization Methodology for Distribution Networks Considering Power Converter Embedded Hybrid On-load Regulator Transformers*","authors":"Xu Yang;Houyu He;Jin Zhu;Hongming Yang;Yu Zheng;Yu Lei;Zhuo Long;Yan Xu","doi":"10.23919/CJEE.2025.000105","DOIUrl":"https://doi.org/10.23919/CJEE.2025.000105","url":null,"abstract":"In addressing voltage overruns and line losses in distribution networks with a high percentage of distributed photovoltaic (PV) connections, traditional on-load regulator transformers can achieve only fixed-step voltage regulation and have a limited switching lifespan. Consequently, a discrete-continuous two-layer optimization methodology for distribution networks, which accounts for power-converter-embedded hybrid on-load regulator transformers, has been proposed to adapt to rapid stochastic fluctuations associated with distribution networks having a high percentage of PV access. In the discrete layer, the mechanical ratio is employed as the decision variable at each moment. In the continuous layer, the power electronic converter ratio, STATCOM compensation capacity, and energy storage charging and discharging power are utilized as decision variables at each moment. A composite optimal allocation model is established with an integrated objective function comprising the PV consumption rate, operating costs, and line losses, while simultaneously ensuring that the voltage at each node remains within the prescribed limits. Based on this model, an improved particle swarm algorithm is employed to determine the optimal configuration. Finally, the efficacy of the proposed method is validated through enhancements of the IEEE 33 node system example.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":"11 1","pages":"105-108"},"PeriodicalIF":0.0,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10955305","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143792905","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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