Research Of High-voltage Active Power Filter Based On TMS320F2812and FPGA

Harmonic pollution of grid current produced by nonlinear loads such aselectrical devices turns to be more and more serious and has become the mainharmonic source of the power system with the widespread usages of those electricalloads. The harmonic pollution of power electrical equipments has seriouslyhindered the development and application of electronic technologies. Thus moreeffective researches of harmonic problems are needed so as to govern harmonicpollution and improve the quality of power supply of gird power system.At present, at home and abroad, passive power filter is mainly used inharmonic suppression of high-voltage grid system. APF has being perfectly appliedin low-voltage distribution network after more than20years of development,however, which applied in high-voltage distribution network is not mature. Highvoltage Active Power Filter (APF) has great application prospect in high-voltagelarge-capacity harmonic control because it effectively combines advantages of lowcost and high reliability of passive power filter and flexible compensation of APF.This paper describes the advantages of a proposed high-voltage APF topologyon the basis of analyzing several existing APF topologies. That is, hybrid cascademultilevel converter of voltage source provides a grid-connecting voltage of whichthe fundamental component is exactly equals to the grid voltage, so that the PWMconverter of current source can run in low voltage environment, then the DCvoltage of current source can be quite low, so that the capacity of the PWMconverter will be very small and active power loss in power conversion will bequite low, therefore, this proposed APF topology can be well used in high voltageoccasion.Algorithm of voltage control of voltage source and compensation and trackingof grid current are proposed, grid-connecting voltage of voltage source is producedby Field-Programmable Gate Array (FPGA) and is managed by controlling thevalue of its DC side voltage using a Digital Signal Processor (DSP), compensationand tracking of harmonic component of grid current is also done in DSP.The system is simulated in Matlab/Simulink, the feasibility and theeffectiveness of the system are validated by analyzing waveforms of grid current before and after connecting the APF and testing performances of which whenchanging harmonic load.The hardware circuit and the experimental prototype are designed and build tomake phased experiments, staged experimental results verifies the reliability of thehigh-voltage APF topology proposed in this paper.