This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The propo...This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM (pulse width modulation) converter. The RSC (rotor side converter) is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC (grid side converter) is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC (point of common coupling) and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved.展开更多
AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for H...AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for HIL (hardware in the loop) simulators required for control, protection design and testing due to the large number of cells that must be simulated individually using very small time steps. This paper demonstrates the advantages of using a very small time step to simulate a MMC topology. The MMC is implemented on FPGA (fiel-programmable gate array) to simulate fast transient with a time step of 250 ns. The AC network and HVDC bus is simulated on the PC, with a slower time step of 10 μs to 20 μs. The simulator architecture and the components simulated on the FPGA and on the PC will be discussed, as well as the method allowing the interconnection of this slow and fast system.展开更多
文摘This paper presents the control ofa WECS (wind energy conversion system), equipped with a DFIG (doubly fed induction generator), for maximum power generation and power quality improvement simultaneously. The proposed control algorithm is applied to a DFIG whose stator is directly connected to the grid and the rotor is connected to the grid through a back-to-back AC-DC-AC PWM (pulse width modulation) converter. The RSC (rotor side converter) is controlled in such a way to extract a maximum power, for a wide range of wind speed. The GSC (grid side converter) is controlled in order to filter harmonic currents of a nonlinear load coupled at the PCC (point of common coupling) and ensure smooth DC bus voltage. Simulation results show that the wind turbine can operate at its optimum energy for a wide range of wind speed and power quality improvement is achieved.
文摘AC-HVDC-AC energy conversion systems using MMC (modular multilevel converters) are becoming popular to integrate distributed energy systems to the main grid. Such multilevel converters pose a serious problems for HIL (hardware in the loop) simulators required for control, protection design and testing due to the large number of cells that must be simulated individually using very small time steps. This paper demonstrates the advantages of using a very small time step to simulate a MMC topology. The MMC is implemented on FPGA (fiel-programmable gate array) to simulate fast transient with a time step of 250 ns. The AC network and HVDC bus is simulated on the PC, with a slower time step of 10 μs to 20 μs. The simulator architecture and the components simulated on the FPGA and on the PC will be discussed, as well as the method allowing the interconnection of this slow and fast system.