双DSP控制的三相四桥臂静止同步补偿器的研究

摘要

针对三相四线制配电网的无功、谐波检测的实时性和零线电流抑制问题,采用了双DSP控制的三相四桥臂静止同步补偿器(STATCOM)解决方案.谐波和无功电流检测方式采用FBD法,可减轻DSP计算量;谐波和无功电流的控制采用电流直接控制方式,其响应速度和控制精度相比间接控制方式有很大提高.系统的数字控制采用双DSP控制方式,一片DSP主要负责信号数据采集,另一片DSP主要负责指令电流的运算,可大幅提高系统的运行速度,保证了STATCOM补偿的实时性.介绍了三相四桥臂STATCOM的检测和控制方式,并对检测原理作了具体的算法推导;绘制了系统的硬件构成图和软件主程序流程图;对系统进行了仿真和实验,STATCOM投入后,系统侧的电流相位可以很好地跟踪电压相位,无功得到很好补偿,电流波形是正弦波,中线电流接近零,谐波和零线电流得到很好的抑制.%To resolve the problem of the reactive power, harmonics real-time detection and zero line current suppression of three-phase four-wire distribution network, the solution of a dual-DSP control of three-phase four-leg STATCOMis used. Using FBD method on the harmonics and reactive power current detection method can reduce the computationof DSP;the control method of harmonics and reactive power current uses a current direct control method, which response speed and control accuracy has greatly improved than the current indirect control method.The digital control ofsystem adopts a dual-DSP control method, one DSP is mainly responsible for signal data acquisition, another piece ofDSP is mainly responsible for instruction current operation, it can greatly improve the speed of system and ensure thecompensation of starcom in real time.This article describes the detection and control method of three-phase four-legSTATCOM, and derives the specific algorithms of the detction principle, draws and elaborates a constitute diagram ofhardware and a main program flow chart of software. During the simulation and experimental of system,after statcominputted, current phase of system tracks good with voltage phase, reactive power is well compensated, current waveformis sine wave, neutral current is close to zero, harmonics and zero line current are well suppressed.