A 50kVA Shunt Active Power Filter Based On Dual DSP

Active power filter has been widely researched and extensively developed in governance of power harmonic, because it can compensate harmonic of which frequency and amplitude are both variable, and has good dynamic characteristics which is free of infection of the resistance in the electrical network.At present, with the use of digital control system, active power filter becomes the most suitable for active power filter,for its flexibility, speed and high reliability features. Compared with the traditional single-DSP control system, the dual-DSP controller tends to have higher computing power and cost-effective.This paper starts from source and harm of harmonics, continues with the principle and structure of APF,and a comparison of several harmonic detection and control methods. Then a design of shunt active power filter based on dual-DSP control has been put forward, with special attention on the control strategy and hardware design.Harmonic current detection method and compensation current control strategy are the two key issues to impact the performance of APF. They are also the focus of the study on active power filters.To achieve the control of APF, the thesis use a method of harmonic detection based on i p _iq Algorithm and make an improvement. An improved Triangular wave comparison control strategy which could minimize the overall current error is proposed through the analysis of the topology of the 3-phase 3-wire voltage APF. It improves the tracking precision of reference currents, and good compensation performance is attained consequently. Meanwhile, in the main circuit structure, the use of LCL filter, improved high frequency switching harmonics suppression. The simulation of APF system based on MATLAB is established and simulation is carried out under various conditions. To realize the algorithms and control strategies proposed in the paper and satisfy the requirement of the APF prototype system, Based on the core of TMS320F2812 and TMS320F28335, a dual-DSP + CDLP + dual-port RAM-based framework is established for high-speed digital signal processing control platform. Based on the control platform, the system control circuit is designed, and its hardware design is introduced in detail. Software design is also introduced, and optimization of modular thinking is made.Then the harmonic compensation experiment is realized on the laboratory prototype of APF, The result of the experiment demonstrates the correctness and feasibility of the algorithm.