The Research And Realization Of100A Shunt Active Power Filter

With the rapid increasing of nonlinear loads and power electronic switching devices in power system, more and more serious harmonic current pollution has done great harm to the utilization of electrical energy and safe operation of other equipment. Active Power Filter is considered as one of the most effective solution to harness harmonic pollution synthetically. It can dynamically eliminate harmonic and compensate reactive power, and has the rosy application prospect. In which the shunt active power filter is used most widely at present and to be a hot researching point. In our country, the research on active power filter began comparative late, the device’s development and its applications are relatively backward. So the research and exploitations in active power filers have important significance.This paper choose three-phase three-wire shunt active power filter as the research object, First of all, the paper expounded its basic working principle, and analyzed its main circuit topology, and established the mathematical model of the topology under d-q synchronous rotating coordinate system. Then, the theory of the instantaneous reactive power in three-phase circuits are analyzed in detail, and based on the theory of instantaneous reactive power, the p-q harmonic detecting method and ip-iq harmonic detecting method have been carried on theoretical analysis and comparison, and the ip-iq harmonic detecting method was chose as the harmonic detection scheme for the APF experimental prototype. In addition, in order to improve the performance of compensation stability and dynamic tracking timeliness of the APF experimental prototype effectively, and according to the characteristics of the compensation harmonic currents’periodicity and repeatability, the paper proposed a set of PI-repetitive current control scheme which is suitable for the APF prototype. In which the repetitive controller is used to improve the steady accuracy of the system and the PI controller is used to ensure the system’s dynamic response speed. The paper carried on the detailed design and derivation for the PI-repetitive controller, and through the simulation verified the validity and effectiveness of the Pi-repetitive control strategy. Then, the hardware circuits and the software programs for100A Shunt Active Power Filter have been analyzed and designed in detailed, and the hardware designs include various components selection and parameter calculation, the paper designed a set of digital control scheme with DSP+FPGA as the core, the scheme adopts the TMS320F28335DSP chip as the main controller, and the FPGA unit is used for PWM signal modulation and IGBT fault protection. The software designs include the main program and the interrupt service subroutine, and the detailed program flow charts are designed. Finally, a100A three-phase three-wire shunt APF experimental prototype was realized. And the paper did some harmonic compensation experiments, the experimental results show that the grid current waveform is obviously improved after compensation, which verifies the feasibility of the entire design and the validity of the APF experimental prototype.