Control Method And System Design Of Distribution Network Static Synchronous Compensator

The static synchronous compensator(STATCOM)has become the latest technology representative in the field of modern reactive power compensation with its advantages of flexible adjustment,rapid response,and low harmonic content.Distribution network static synchronous compensator(DSTATCOM),as a derivative of STATCOM in distribution network applications,plays an important role in improving power quality.Therefore,it is of great significance to study the control method and system design of DSTATCOM.This paper takes DSTATCOM as the research object,expatiates the traditional control method as well as detection technology,and points out the areas that can be improved.Then the dynamic high-quality control,the new detection method,the hardware and the software design have been investigated.At the same time,it proposes feasible solutions for current surges and arcing that are caused by device start-up and shutdown.The paper begins by analyzing the working principle of DSTATCOM under ideal conditions and non-ideal conditions,then uses the switch function description method to perform mathematical modeling in the abc coordinate system,and converts and analyzes the mathematical model in different coordinate systems.This lays a theoretical foundation for full-text research.The traditional double closed-loop voltage feedforward decoupling control and double closed-loop non-decoupling control strategy of DSTATCOM are studied and the improvement can be pointed out.To this end,a novel control principle of a three-phase system without PLL is discussed.Afterwards,due to the consideration that the daily load is dominated by a single phase,the voltage equalization strategy for the single-phase cascaded H-bridge DSTATCOM system was explored.Theoretical research and simulation results show the feasibility and effectiveness of each control method.Then,the compensation current detection principle of the three-phase DSTATCOM system based on the p-q method and dq method is studied.An improved dq compensation current detection principle is proposed.At the same time,the dual-loop detection and control strategy of capacitance split-type three-phase four-wire DSTATCOM system based on the coordinate transformation between three-dimensional AC and DC is studied.Theoretical research and simulation results show the correctness and effectiveness of the compensation current detection principle.Finally,there is a great deal of current impact phenomenon in the start of the simulated device,and a principle of software startup algorithm based on the pre-charge circuit and a system shutdown plan are proposed.Afterwards,a detailed three-phase and single-phase DSTATCOM system hardware and software design is performed with the help of the laboratory's existing power modules,and platform control strategy verification was carried out.The experimental results show the correctness,intelligence of system design.At the same time,some installations have been linked to start-up data to enhance the credibility of the experiment.