Research On New Control Algorithm For Unified Power Quality Conditioner

As a new control device of power quality, Unified Power Quality Conditioner (UPQC) is an important research aspect of power electronics. It is a powerful tool to compensate the fluctuation and harmonic of power line voltage, and reactive power and harmonic current of loads.On the basic of preceding work of this project and the research production of this field, the structure, detect and control method are analyzed. And the control method is researched as a major aspect in this paper.In this paper, one-cycle control method, which is used to control the Active Power Filter (APF) widely, is deeply studied. And a one-cycle control method for Dynamic Voltage Restorer (DVR) is presented. According to the structure characteristic of UPQC, a one-cycle control method for UPQC is mentioned. It has simplified circuit, high precision and effectual compensation. The simulation results verify the feasibility and advantage of this method.In the preceding work, the synchronal deadbeat control and robust control method for UPQC are mentioned. But these methods base on a unified math model. Aiming this flaw, the fuzzy control method for UPQC is mentioned in this paper. It adapts well to the non-linearity and instability of electric power system. But when the system parameters have a perturbed problem, the controller parameter cannot tune by itself. Therefore, a parameter self-tuning PI controller based on fuzzy inference method and a fuzzy controller based on neural network are mentioned in this paper. The simulation results verify that the intelligent control method is effectual and its improver is advanced.At last, this paper basically realizes routine control of UPQC. The main circuit is built based on the 7MBP50RA120. And the parameters of main circuit are designed such as coupling transformer on the series side, capacitance of converter and so on. The control circuit uses TMS320F2812 as the central control unit. It also contains power supply circuit, detection circuit for sensor and zero-crossing detector and isolation circuit. The software program for UPQC is designed. And the experiment curve is analyzed.