In the future, the power quality will decrease by the introduction of a lot of renewable energy sources. The topic of this research is a new method of operation of PCS （power conditioning systems） in the future dist...In the future, the power quality will decrease by the introduction of a lot of renewable energy sources. The topic of this research is a new method of operation of PCS （power conditioning systems） in the future distribution system. The purpose of this research is development of PCS with a function of improvement of the distribution system. Therefore, the authors propose a method of the power quality improvement of the distribution system by PCS. In addition, the authors construct the control logic to use in PCS The control logic suggests adding harmonic restraint function to conventional control. These were verified by simulation and an experiment. As the results, we confirmed that basic operation of PCS being carried out, harmonics were restrained, and power quality had improved.展开更多
An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse o...An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse of the system.The existing frequency control methods use traditional proportion integration(PI)controllers,which cannot adjust PI parameters in real-time to respond to the status changes of the system.Hierarchical control driven by fuzzy logic allows real-time adjustment of the PI parameters and the method used a two-layer control structure.The primary control used droop control to adjust power distribution,and fuzzy logic was used in the voltage loop of the primary control.The secondary control was added to make up for frequency deviation caused by droop control,and fuzzy logic was used in the secondary frequency control to deal with the dynamic change of frequency caused by the disturbances of loads.The proposed method was simulated in Matlab/Simulink.In the primary control,the proposed method reduced the total harmonic distortion(THD)of two cycles of the output voltage from 4.19%to 3.89%;in the secondary control,the proposed method reduced the frequency fluctuation of the system by about 0.03 Hz and 0.04 Hz when the load was increased and decreased,respectively.The results show that the proposed methods have a better effect on frequency maintenance and voltage control of the AC microgrid.展开更多
文摘In the future, the power quality will decrease by the introduction of a lot of renewable energy sources. The topic of this research is a new method of operation of PCS （power conditioning systems） in the future distribution system. The purpose of this research is development of PCS with a function of improvement of the distribution system. Therefore, the authors propose a method of the power quality improvement of the distribution system by PCS. In addition, the authors construct the control logic to use in PCS The control logic suggests adding harmonic restraint function to conventional control. These were verified by simulation and an experiment. As the results, we confirmed that basic operation of PCS being carried out, harmonics were restrained, and power quality had improved.
基金National Natural Science Foundation of China(No.62303107)Fundamental Research Funds for the Central Universities,China(Nos.2232022G-09 and 2232021D-38)Shanghai Sailing Program,China(No.21YF1400100)。
文摘An alternating current(AC)microgrid is a system that integrates renewable power,power converters,controllers and loads.Hierarchical control can manage the frequency of the microgrid to prevent imbalance and collapse of the system.The existing frequency control methods use traditional proportion integration(PI)controllers,which cannot adjust PI parameters in real-time to respond to the status changes of the system.Hierarchical control driven by fuzzy logic allows real-time adjustment of the PI parameters and the method used a two-layer control structure.The primary control used droop control to adjust power distribution,and fuzzy logic was used in the voltage loop of the primary control.The secondary control was added to make up for frequency deviation caused by droop control,and fuzzy logic was used in the secondary frequency control to deal with the dynamic change of frequency caused by the disturbances of loads.The proposed method was simulated in Matlab/Simulink.In the primary control,the proposed method reduced the total harmonic distortion(THD)of two cycles of the output voltage from 4.19%to 3.89%;in the secondary control,the proposed method reduced the frequency fluctuation of the system by about 0.03 Hz and 0.04 Hz when the load was increased and decreased,respectively.The results show that the proposed methods have a better effect on frequency maintenance and voltage control of the AC microgrid.
