Conventional sliding-mode observer (SMO)-based grid-voltage observation methods often require a low-pass filter (LPF) to remove high-frequency sliding-mode noise. However, a complicated phase- and amplitude-compensation method, which is highly sensitive to the DC-offset, is required. A frequency-adaptive dual second-order generalized integrator (SOGI) can be used to replace the LPF, eliminating the compensation link and the effects of the DC-offset; however, strong coupling is introduced between the front-end SOGI block and back-end phase-locked loop (PLL) block, thereby reducing the dynamic performance. To solve this problem, this study proposes an SMO-based grid-voltage observation method with a frequency-fixed dual SOGI and cross-compensated PLL that can eliminate the frequency coupling between the front-end SOGI block and back-end PLL blocks, thereby increasing its dynamic performance. In this study, the phase and amplitude are compensated simultaneously using the proposed cross-compensation method, achieving an accurate observation of the grid voltage under off-nominal frequencies. An analysis of the small-signal model theoretically verified that the proposed method has good dynamic performance. Finally, the superiority of the proposed method is verified through comparative experiments.
{"title":"Sliding-Mode Observer-Based Grid Voltage-Observation Method with Frequency-Fixed Dual SOGI and Cross-Compensated Phase-Locked Loop","authors":"Leilei Guo;Qingyang Ye;Nan Jin;Zhenkun Liu;Zhenjun Wu","doi":"10.23919/CJEE.2024.000090","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000090","url":null,"abstract":"Conventional sliding-mode observer (SMO)-based grid-voltage observation methods often require a low-pass filter (LPF) to remove high-frequency sliding-mode noise. However, a complicated phase- and amplitude-compensation method, which is highly sensitive to the DC-offset, is required. A frequency-adaptive dual second-order generalized integrator (SOGI) can be used to replace the LPF, eliminating the compensation link and the effects of the DC-offset; however, strong coupling is introduced between the front-end SOGI block and back-end phase-locked loop (PLL) block, thereby reducing the dynamic performance. To solve this problem, this study proposes an SMO-based grid-voltage observation method with a frequency-fixed dual SOGI and cross-compensated PLL that can eliminate the frequency coupling between the front-end SOGI block and back-end PLL blocks, thereby increasing its dynamic performance. In this study, the phase and amplitude are compensated simultaneously using the proposed cross-compensation method, achieving an accurate observation of the grid voltage under off-nominal frequencies. An analysis of the small-signal model theoretically verified that the proposed method has good dynamic performance. Finally, the superiority of the proposed method is verified through comparative experiments.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707126","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397472","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 this study, a comprehensive approach is presented for the sizing and management of hybrid renewable energy systems (HRESs) that incorporate a variety of energy sources, while emphasizing the role of artificial neural networks (ANNs) in system management. For optimal sizing of an HRES, the monthly average method wherein historical weather data are used to calculate the monthly averages of solar irradiance and wind speed, offering a well-balanced strategy for system sizing. This ensures that the HRES is appropriately scaled to meet the actual energy requirements of the specified location, avoiding the pitfalls of over- and under-sizing, and thereby enhancing the operational efficiency. Furthermore, the study details a cutting-edge strategy that employs ANNs for managing the inherent complexities of HRESs. It elaborates on the design, modeling, and control strategies for the HRES components by utilizing Matlab/Simulink for implementation. The findings demonstrate the proficiency of the ANN -based power manager in determining the operational modes guided by a specifically designed flowchart. By integrating ANN-driven energy management strategies into an HRES, the proposed approach marks a significant advancement in system adaptability, precision control, and efficiency, thereby maximizing the effective utilization of renewable resources.
本研究提出了一种综合方法，用于确定包含多种能源的混合可再生能源系统（HRES）的规模和管理，同时强调了人工神经网络（ANN）在系统管理中的作用。为了优化可再生能源混合系统的规模，采用了月平均法，即利用历史天气数据计算太阳能辐照度和风速的月平均值，为系统规模的确定提供了一种均衡的策略。这可确保太阳能热发电系统的规模适当，以满足指定地点的实际能源需求，避免规模过大或过小的陷阱，从而提高运行效率。此外，该研究还详细介绍了一种先进的策略，即利用人工智能网络来管理 HRES 固有的复杂性。研究详细阐述了利用 Matlab/Simulink 实现 HRES 组件的设计、建模和控制策略。研究结果表明，在专门设计的流程图指导下，基于 ANN 的电力管理器能够熟练地确定运行模式。通过将 ANN 驱动的能源管理策略集成到 HRES 中，所提出的方法标志着在系统适应性、精确控制和效率方面的重大进步，从而最大限度地有效利用可再生资源。
{"title":"Intelligent Energy Management Strategy and Sizing Methodology for Hybrid Systems in Isolated Regions","authors":"Moufida Saadi;Dib Djalel;Billel Meghni;Djamila Rekioua","doi":"10.23919/CJEE.2024.000091","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000091","url":null,"abstract":"In this study, a comprehensive approach is presented for the sizing and management of hybrid renewable energy systems (HRESs) that incorporate a variety of energy sources, while emphasizing the role of artificial neural networks (ANNs) in system management. For optimal sizing of an HRES, the monthly average method wherein historical weather data are used to calculate the monthly averages of solar irradiance and wind speed, offering a well-balanced strategy for system sizing. This ensures that the HRES is appropriately scaled to meet the actual energy requirements of the specified location, avoiding the pitfalls of over- and under-sizing, and thereby enhancing the operational efficiency. Furthermore, the study details a cutting-edge strategy that employs ANNs for managing the inherent complexities of HRESs. It elaborates on the design, modeling, and control strategies for the HRES components by utilizing Matlab/Simulink for implementation. The findings demonstrate the proficiency of the ANN -based power manager in determining the operational modes guided by a specifically designed flowchart. By integrating ANN-driven energy management strategies into an HRES, the proposed approach marks a significant advancement in system adaptability, precision control, and efficiency, thereby maximizing the effective utilization of renewable resources.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707120","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397473","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}
Droop-controlled voltage-source converters (VSCs) can provide frequency and voltage support to power grids. However, during a grid fault, VSCs may experience transient instability, which can be significantly affected by both the control parameters and fault conditions. This mechanism has not been fully elucidated in previous studies. In particular, grid-voltage faults are commonly accompanied by a grid voltage phase-angle jump (VPAJ), which is typically ignored in the evaluation of the transient stability of VSCs. To address this issue, this study comprehensively assesses the impact of the VPAJ and key control parameters on the transient characteristics of VSCs. Furthermore, the critical clearing angle and critical clearing time are quantitatively calculated to define the transient stability boundary. In addition, a transient stability-enhancement control method that considers the transient stability constraints is proposed. Finally, simulations and experimental tests are conducted to validate both the theoretical analysis and proposed method.
{"title":"Design-Oriented Transient Stability Assessment for Droop-Controlled Converter Considering Grid Voltage Phase-Angle Jump","authors":"Pingjuan Ge;Hailiang Xu;Ruitong Mao;Chunming Tu;Fan Xiao;Qi Guo","doi":"10.23919/CJEE.2024.000092","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000092","url":null,"abstract":"Droop-controlled voltage-source converters (VSCs) can provide frequency and voltage support to power grids. However, during a grid fault, VSCs may experience transient instability, which can be significantly affected by both the control parameters and fault conditions. This mechanism has not been fully elucidated in previous studies. In particular, grid-voltage faults are commonly accompanied by a grid voltage phase-angle jump (VPAJ), which is typically ignored in the evaluation of the transient stability of VSCs. To address this issue, this study comprehensively assesses the impact of the VPAJ and key control parameters on the transient characteristics of VSCs. Furthermore, the critical clearing angle and critical clearing time are quantitatively calculated to define the transient stability boundary. In addition, a transient stability-enhancement control method that considers the transient stability constraints is proposed. Finally, simulations and experimental tests are conducted to validate both the theoretical analysis and proposed method.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707124","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397128","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 : 2024-09-01DOI: 10.23919/CJEE.2024.000089
Ning Xie;Wei Zhao;Wenzhi Lin;Zhenglei Wang;Yukai Chen;Chengzhi Li;Jianfei Chen
Capacitor voltage imbalance in four-level (4L) neutral-point clamped (NPC) converters is a direct factor hindering their application. In particular, when they are applied in motor drives, space vector pulse-width modulation (SVPWM) is a more popular scheme, but conventional 4L SVPWM cannot achieve the voltage balancing control of DC-link capacitors, is complex to implement, and requires costly computation. A hybrid modulation method with capacitor voltage-balancing control for 4L NPC converters is proposed. The proposed method is achieved using three-level (3L) SVPWM and two-level (2L) carrier-based pulse-width modulation (CPWM) based on the concept of “4L=3L+2L”. Thus, it can be easily implemented on a digital chip because the modulation process is nearly identical to that of 3L SVPWM without the more cumbersome 4L SVPWM algorithm. Meanwhile, any proven optimization scheme of 3L SVPWM can be directly applied to the proposed method to further improve performance. Simulation and experimental results for a 4L active NPC converter demonstrate the effectiveness of the proposed method.
{"title":"Hybrid Modulation Strategy with Voltage Balancing Control for Four-Level Neutral-Point Clamped Converters","authors":"Ning Xie;Wei Zhao;Wenzhi Lin;Zhenglei Wang;Yukai Chen;Chengzhi Li;Jianfei Chen","doi":"10.23919/CJEE.2024.000089","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000089","url":null,"abstract":"Capacitor voltage imbalance in four-level (4L) neutral-point clamped (NPC) converters is a direct factor hindering their application. In particular, when they are applied in motor drives, space vector pulse-width modulation (SVPWM) is a more popular scheme, but conventional 4L SVPWM cannot achieve the voltage balancing control of DC-link capacitors, is complex to implement, and requires costly computation. A hybrid modulation method with capacitor voltage-balancing control for 4L NPC converters is proposed. The proposed method is achieved using three-level (3L) SVPWM and two-level (2L) carrier-based pulse-width modulation (CPWM) based on the concept of “4L=3L+2L”. Thus, it can be easily implemented on a digital chip because the modulation process is nearly identical to that of 3L SVPWM without the more cumbersome 4L SVPWM algorithm. Meanwhile, any proven optimization scheme of 3L SVPWM can be directly applied to the proposed method to further improve performance. Simulation and experimental results for a 4L active NPC converter demonstrate the effectiveness of the proposed method.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707122","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397126","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 : 2024-09-01DOI: 10.23919/CJEE.2024.000088
Peijin Liu;Tao Huang;Yong Chen;Lei Dong;Fei Yu
A dynamic reconfiguration method for photovoltaic (PV) arrays based on an improved dung beetle algorithm (IDBO) to address the issue of PV array mismatch loss caused by partial shading conditions (PSCs) is proposed. To establish the output power-current (P-I) segmentation function for the total-cross-tied (TCT) PV array and the constraint function for the electrical switches, the IDBO algorithm was used to optimize both the P-I segmentation function and the electrical switch constraint function. IDBO is compared with algorithm-free reconfiguration and five other heuristic algorithms using two evaluation criteria: mismatch loss and power enhancement percentage, across six shading scenarios for 6×6 PV arrays. The irradiation distribution of PV arrays reconfigured by IDBO is also presented. The results show that IDBO effectively increases the output power of PV arrays and reduces mismatch loss. The output PV curves tend to exhibit a single peak, and the reconstruction results are superior to those obtained with the other methods.
{"title":"Dynamic Reconstruction of Total-Cross-Tied Photovoltaic Array Based on Arrays Using an Improved Dung Beetle Algorithm","authors":"Peijin Liu;Tao Huang;Yong Chen;Lei Dong;Fei Yu","doi":"10.23919/CJEE.2024.000088","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000088","url":null,"abstract":"A dynamic reconfiguration method for photovoltaic (PV) arrays based on an improved dung beetle algorithm (IDBO) to address the issue of PV array mismatch loss caused by partial shading conditions (PSCs) is proposed. To establish the output power-current (P-I) segmentation function for the total-cross-tied (TCT) PV array and the constraint function for the electrical switches, the IDBO algorithm was used to optimize both the P-I segmentation function and the electrical switch constraint function. IDBO is compared with algorithm-free reconfiguration and five other heuristic algorithms using two evaluation criteria: mismatch loss and power enhancement percentage, across six shading scenarios for 6×6 PV arrays. The irradiation distribution of PV arrays reconfigured by IDBO is also presented. The results show that IDBO effectively increases the output power of PV arrays and reduces mismatch loss. The output PV curves tend to exhibit a single peak, and the reconstruction results are superior to those obtained with the other methods.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10707123","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397129","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}
Efficient assessment of battery degradation is important to effectively utilize and maintain battery management systems. This study introduces an innovative residual convolutional network (RCN)-gated recurrent unit (GRU) model to accurately assess health of lithium-ion batteries on multiple time scales. The model employs a soft parameter-sharing mechanism to identify both short-and long-term degradation patterns. The continuously looped $Q(V), T(V), frac{mathrm{d}Q}{mathrm{d}V}$ , and $frac{mathrm{d}T}{mathrm{d}V}$ are extracted to form a four-channel image, from which the RCN can automatically extract the features and the GRU can capture the temporal features. By designing a soft parameter-sharing mechanism, the model can seamlessly predict the capacity and remaining useful life (RUL) on a dual time scale. The proposed method is validated on a large MIT-Stanford dataset comprising 124 cells, showing a high accuracy in terms of mean absolute errors of 0.004 77 for capacity and 83 for RUL. Furthermore, studying the partial voltage fragment reveals the promising performance of the proposed method across various voltage ranges. Specifically, in the partial voltage segment of 2.8-3.2 V, root mean square errors of 0.010 7 for capacity and 140 for RUL are achieved.
{"title":"A Multitime-Scale Deep Learning Model for Lithium-ion Battery Health Assessment Using Soft Parameter-sharing Mechanism","authors":"Lulu Wang;Kun Zheng;Yijing Li;Zhipeng Yang;Feifan Zhou;Jia Guo;Jinhao Meng","doi":"10.23919/CJEE.2024.000085","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000085","url":null,"abstract":"Efficient assessment of battery degradation is important to effectively utilize and maintain battery management systems. This study introduces an innovative residual convolutional network (RCN)-gated recurrent unit (GRU) model to accurately assess health of lithium-ion batteries on multiple time scales. The model employs a soft parameter-sharing mechanism to identify both short-and long-term degradation patterns. The continuously looped \u0000<tex>$Q(V), T(V), frac{mathrm{d}Q}{mathrm{d}V}$</tex>\u0000, and \u0000<tex>$frac{mathrm{d}T}{mathrm{d}V}$</tex>\u0000 are extracted to form a four-channel image, from which the RCN can automatically extract the features and the GRU can capture the temporal features. By designing a soft parameter-sharing mechanism, the model can seamlessly predict the capacity and remaining useful life (RUL) on a dual time scale. The proposed method is validated on a large MIT-Stanford dataset comprising 124 cells, showing a high accuracy in terms of mean absolute errors of 0.004 77 for capacity and 83 for RUL. Furthermore, studying the partial voltage fragment reveals the promising performance of the proposed method across various voltage ranges. Specifically, in the partial voltage segment of 2.8-3.2 V, root mean square errors of 0.010 7 for capacity and 140 for RUL are achieved.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10596096","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397130","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 : 2024-07-11DOI: 10.23919/CJEE.2024.000082
Wan Feng;Mengdi Li;Wenjuan Zhang;Shoudao Huang;Haixia Zhang
It is difficult for the traditional PI controller to meet high-performance control requirements under the demagnetization fault of a permanent magnet synchronous motor (PMSM). To address this problem, this study proposes a novel sliding mode fault-tolerant control method for PMSM demagnetization faults. First, the mathematical model of PMSM under demagnetization fault state is established, and the reasons for poor fault tolerance of the conventional PI controller are analyzed. A new convergence law is used to design the speed loop sliding mode feedback controller, and its stability is demonstrated. Meanwhile, an adaptive forgetting factor recursive least squares (AFRLS) flux linkage observer is designed to keep the controller parameter values in line with the actual motor parameter values, to reduce the impact of demagnetization faults on motor control performance and achieve fault-tolerant control of demagnetization faults. Finally, simulation and experimental comparison with conventional PI control demonstrate that the proposed method is more robust and resistant to interference.
传统的 PI 控制器很难满足永磁同步电机（PMSM）退磁故障下的高性能控制要求。针对这一问题，本研究提出了一种新型的 PMSM 失磁故障滑模容错控制方法。首先，建立了 PMSM 在退磁故障状态下的数学模型，并分析了传统 PI 控制器容错性差的原因。利用新的收敛规律设计了速度环滑模反馈控制器，并证明了其稳定性。同时，设计了自适应遗忘因子递归最小二乘（AFRLS）磁通量联动观测器，使控制器参数值与电机实际参数值保持一致，降低了退磁故障对电机控制性能的影响，实现了退磁故障的容错控制。最后，通过与传统 PI 控制的仿真和实验对比，证明了所提出的方法具有更强的鲁棒性和抗干扰性。
{"title":"Sliding Mode Fault-Tolerant Control Based on Fast Convergence Law for Faults of PMSM","authors":"Wan Feng;Mengdi Li;Wenjuan Zhang;Shoudao Huang;Haixia Zhang","doi":"10.23919/CJEE.2024.000082","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000082","url":null,"abstract":"It is difficult for the traditional PI controller to meet high-performance control requirements under the demagnetization fault of a permanent magnet synchronous motor (PMSM). To address this problem, this study proposes a novel sliding mode fault-tolerant control method for PMSM demagnetization faults. First, the mathematical model of PMSM under demagnetization fault state is established, and the reasons for poor fault tolerance of the conventional PI controller are analyzed. A new convergence law is used to design the speed loop sliding mode feedback controller, and its stability is demonstrated. Meanwhile, an adaptive forgetting factor recursive least squares (AFRLS) flux linkage observer is designed to keep the controller parameter values in line with the actual motor parameter values, to reduce the impact of demagnetization faults on motor control performance and achieve fault-tolerant control of demagnetization faults. Finally, simulation and experimental comparison with conventional PI control demonstrate that the proposed method is more robust and resistant to interference.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10596094","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397474","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 : 2024-06-13DOI: 10.23919/CJEE.2024.000065
Tongming Li;Fei Gao;Yigeng Huangfu
Energy shortages have hindered global economic development. By utilizing waste as a substrate for microbial fermentation, hydrogen production can transform waste into a valuable resource, significantly reducing the cost of hydrogen production and addressing a significant hurdle in achieving large-scale production of microbial hydrogen. This approach has significant potential for future hydrogen-production applications. Two-stage indirect photohydrolysis has recently emerged as a promising and efficient method for hydrogen production using cyanobacteria and green algae. However, this method cannot be directly applied to organic wastewater for hydrogen production. In contrast, dark fermentation by bacteria, particularly ethanol-type fermentation, is highly efficient for producing hydrogen. Therefore, the combination of the indirect photohydrolysis of algae and dark fermentation by bacteria is expected to significantly enhance the hydrogen-production capacity of organic wastewater, laying the groundwork for future large-scale microbial hydrogen production. This study reviews the main types and technical principles of microbial hydrogen production from waste, available waste types, research progress in the microbial hydrogen-production process, strategies to improve the hydrogen-production rate, and challenges faced during industrialization. Future research directions for microbial-waste hydrogen production are also proposed. The aim of this study is to provide a valuable reference for large-scale biological hydrogen-production research.
{"title":"Biological Hydrogen Production: A Comprehensive Review for Converting Wastes into Wealth","authors":"Tongming Li;Fei Gao;Yigeng Huangfu","doi":"10.23919/CJEE.2024.000065","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000065","url":null,"abstract":"Energy shortages have hindered global economic development. By utilizing waste as a substrate for microbial fermentation, hydrogen production can transform waste into a valuable resource, significantly reducing the cost of hydrogen production and addressing a significant hurdle in achieving large-scale production of microbial hydrogen. This approach has significant potential for future hydrogen-production applications. Two-stage indirect photohydrolysis has recently emerged as a promising and efficient method for hydrogen production using cyanobacteria and green algae. However, this method cannot be directly applied to organic wastewater for hydrogen production. In contrast, dark fermentation by bacteria, particularly ethanol-type fermentation, is highly efficient for producing hydrogen. Therefore, the combination of the indirect photohydrolysis of algae and dark fermentation by bacteria is expected to significantly enhance the hydrogen-production capacity of organic wastewater, laying the groundwork for future large-scale microbial hydrogen production. This study reviews the main types and technical principles of microbial hydrogen production from waste, available waste types, research progress in the microbial hydrogen-production process, strategies to improve the hydrogen-production rate, and challenges faced during industrialization. Future research directions for microbial-waste hydrogen production are also proposed. The aim of this study is to provide a valuable reference for large-scale biological hydrogen-production research.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10557517","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397124","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 : 2024-06-13DOI: 10.23919/CJEE.2024.000073
Xuefeng Yu;Xiaoyong Zhu;Li Quan;Zixuan Xiang;Deyang Fan
With the increasing complexity of electrical vehicles (EVs), the wide-speed-range high-efficiency characteristics of EV drive motors are in strict demand. In this study, the variable magnetic flux effect is introduced into a permanent magnet (PM) motor, and a variable magnetic flux permanent magnetic (VMF-PM) motor is proposed. First, the flux is adjusted flexibly to synchronously broaden the speed regulation range and high-efficiency region. Subsequently, an efficiency analytical model is developed considering the motor speed, current, and flux variations. It is indicated that by the purposeful design of the variable flux leakage topology, the efficiency under high speed can be improved based on a theoretical investigation of the high-efficiency boundary. In addition, based on finite element analysis, the performances before and after optimization of the key parameters of the VMF-PM motor are investigated, including the flux variable characteristics and efficiency characteristics. Finally, a prototype motor is built and tested. Both theoretical analysis and experimental results confirm that based on the assistance of the variable magnetic flux effect, the motor high-efficiency region is broadened effectively, providing a potential research path for designing a wide-speed-range high-efficiency motor.
{"title":"Investigation and Regulation of High-Efficiency Region Boundary of Variable Magnetic Flux Permanent Magnet Motor","authors":"Xuefeng Yu;Xiaoyong Zhu;Li Quan;Zixuan Xiang;Deyang Fan","doi":"10.23919/CJEE.2024.000073","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000073","url":null,"abstract":"With the increasing complexity of electrical vehicles (EVs), the wide-speed-range high-efficiency characteristics of EV drive motors are in strict demand. In this study, the variable magnetic flux effect is introduced into a permanent magnet (PM) motor, and a variable magnetic flux permanent magnetic (VMF-PM) motor is proposed. First, the flux is adjusted flexibly to synchronously broaden the speed regulation range and high-efficiency region. Subsequently, an efficiency analytical model is developed considering the motor speed, current, and flux variations. It is indicated that by the purposeful design of the variable flux leakage topology, the efficiency under high speed can be improved based on a theoretical investigation of the high-efficiency boundary. In addition, based on finite element analysis, the performances before and after optimization of the key parameters of the VMF-PM motor are investigated, including the flux variable characteristics and efficiency characteristics. Finally, a prototype motor is built and tested. Both theoretical analysis and experimental results confirm that based on the assistance of the variable magnetic flux effect, the motor high-efficiency region is broadened effectively, providing a potential research path for designing a wide-speed-range high-efficiency motor.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10557492","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397475","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 : 2024-06-13DOI: 10.23919/CJEE.2024.000078
Wentao Zhang;Haiyang Gao;Yongxiang Xu;Jibin Zou
Permanent magnet synchronous motors (PMSMs) driven by voltage source inverters (VSIs) with pulse width modulation (PWM) are widely used. Given the impact of acoustic noise on the environment and human ears, the comfort level of the high-frequency vibration noise emitted by PMSMs has become an important factor. This study introduces the current mainstream high-frequency vibration noise suppression strategies for PMSMs by reducing the high-frequency current harmonics of stator windings, including spread spectrum technology, vector position exchange technology, and interleaved parallel technology. Furthermore, this study analyzed and compared the advantages and disadvantages of various suppression strategies.
{"title":"Review of High-Frequency PWM Acoustic Noise Suppression Methods for PMSMs","authors":"Wentao Zhang;Haiyang Gao;Yongxiang Xu;Jibin Zou","doi":"10.23919/CJEE.2024.000078","DOIUrl":"https://doi.org/10.23919/CJEE.2024.000078","url":null,"abstract":"Permanent magnet synchronous motors (PMSMs) driven by voltage source inverters (VSIs) with pulse width modulation (PWM) are widely used. Given the impact of acoustic noise on the environment and human ears, the comfort level of the high-frequency vibration noise emitted by PMSMs has become an important factor. This study introduces the current mainstream high-frequency vibration noise suppression strategies for PMSMs by reducing the high-frequency current harmonics of stator windings, including spread spectrum technology, vector position exchange technology, and interleaved parallel technology. Furthermore, this study analyzed and compared the advantages and disadvantages of various suppression strategies.","PeriodicalId":36428,"journal":{"name":"Chinese Journal of Electrical Engineering","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10557519","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142397476","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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