Research On Control Algorithm For Unified Power Quality Conditioner

The unified conditioning technology of power quality, which based on power electronic technology and crossed by many subject (the electric power system, the signal processing and the control theories etc), belongs to one of important contents of custom power,. The unified power quality conditioner (UPQC) can not only compensate voltage flickers, sag, fluctuate and voltage imbalance, but also compensate harmonics and reactive power. Traditionally, the device for power quality conditioner can compensate distorted voltage and current harmonic respectively. However, UPQC has capacity of simultaneously coordinating voltage and current compensate and satisfy the demand of the power consumer and supply system. In a word, the UPQC is a multifunctional custom power controller. The structure, detect and control method are deeply analyze. These control method are divided into the two major types, and put forward existent problem of these control method. According to present problems, the series inverter and the parallel inverter of UPQC have been treating as a unified unit, building the unified model, which contains UPQC, electric power and load. On the foundation of this model, the deadbeat control algorithm and the robust control algorithm have been present. The deadbeat control algorithm easy to be digitalized and can compensate the delay caused by a great deal of computation. The robust control algorithm reduces the calculate capacity. Both controls algorithms are simultaneously compute the reference of series part and shunt part, which simultaneously harmonize voltage compensate and current compensate. The robustness of both algorithms is also discussed in this paper. The parameters of power circuit and filter circuit are initiatively designed, and all parameters are optimized using the Matlab/Simulation. On the foundation of simulation model, the simulation results have been obtained. The results verify that both controls algorithms simultaneously harmonize voltage compensate and current compensate, and the better dynamic performance has been obtained than tradition algorithm. The shunt part of UPQC based on DSP has been designed and construct. It contains DSP control circuit, power supply circuit, isolation circuit, IPM and filter circuit. Control and drive circuit used TMS320LF2407 as the central control unit so that realize full digital compensate, which make the best of the resource of DSP and enhance the precision and performance of UPQC system; Power circuit choose 7MBP50RA120, which achieve kinds of protect; The value of filter capacitance and inductance, which are the key of compensate performance, have been designed.