Research Of Static Synchronous Compensator And Control Strategy

With the improvement of industry, the power customer are more and more particular about the power supply quality and dependability. At present, the reactive load, especially the impulsive reactive load, it not only increases power loss but also seriously deteriorates the power quality of customers. Distribution network for Static Synchronous Compensator (D-STATCOM) is an important one of dynamic reactive power compensation devices, because of it good compensation performance can be tracked compensation of reactive power distribution network, and also can reduce the impact of loading on the impact of distribution network. The core research of D-STATCOM technology is the converter and its control strategy.This paper presents some control strategy, introduces inverse system method and differential geometry method, especially introduces direct current control method. This paper presents different direct-current control method.STATCOM converter device-level control strategy have been studied for direct current control and indirect current control of the commonly used methods of study, discussion of the STATCOM in the square wave mode and PWM mode control method used. Introduced two type of the inverse system method and differential geometry which using in the nonlinear systems. Summing up the method of the direct current control, presenting the control method that using in the paper.The establishment of voltage source inverter per-unit of the standard model, analysis the performance of the two device parameters of the rated capacity of reactive power compensation Q_N and the maximum output ripple I_纹波, the relationship with the main circuit parameters; the main circuit parameters including the work of DC side voltage U_dc, series resistance value L and the carrier ratio n and the constraints of these numbers. In parallel to the staggered structure of multi-drive converter main circuit parameters for the design found in contrast, multi-drive staggered parallel design bridge structure, the constraints relationship of these are relatively small. This is provide more choice for the select of the mainly circuit parameters, comparing to traditional PWM control method, its easier to obtain good system performance.By the research of main circuit structure and control method about multi-drive staggered control, the main circuit parameters are designed for four-drive staggered to control device, and main circuit devices are selected. Control system is realized with the digital device, the steady-state characteristics and dynamic characteristics are verified by simulation of the control system.Establishment all aspects of the device models, application the typical linear I systems and the typical type II system control theory, direct current control of the current regulator and voltage regulator design parameters, and to verify the simulation and control system part of the realization of specific programs.Finally, the development of the prototype was tested. Test waveform can be seen through a multi-staggered drive D-STATCOM technology compared to conventional D-STATCOM, which have a distinct advantage in reducing the output ripple and ripple DC.