Design And Research Of UPQC Prototype Based On Modular Multilevel Converter

With the rapid development of our country’s electric power system, the modern electric network is moving towards the direction that its structure is more and more complex and its capacity is increasing, attendant for power quality issues are also receiving more and more attention by more and more people. How to be more efficient, more comprehensive to solve power quality problems, has become an issue to be solved. As a powerful power quality comprehensive compensation device, the parallel of Unified Power Quality (UPQC) has the function of the STATCOM, APF, and its series has the function of the DVR, DUPS. The UPQC can not only run independently to realize its function of every part, but also be used as a whole part to better solve the problem of complex power quality.Firstly, the article analyzes the topology structure and the output principle of MMC-UPQC prototype. For the practical need of UPQC prototype, the parameters of the key components in the main circuit (including bridge arm reactance and the charging resistance, etc.) is calculated and researched in detail. By using PSCAD simulation, the article analyzes the relationship between the number of MMC level and the performance of the output voltage; and based on this, the number of MMC level is determined.Secondly, the article designs the main circuit parameters and the control system of the power module. Respectively tests the power module design by no-load test, power test and integrated test. The results verify the validity of the power module design.Thirdly, the article analyzes and researches the control strategies of UPQC prototype. And establish a13-level MMC-UPQC model in PSCAD/EMTDC experimental platform. And the ultimate consequence is that the simulation results verify the effectiveness of the control strategies.Finally, the article develops the human-computer interaction which is suited for UPQC prototype by using the LabVIEW software. And elaborates the design of the control system of the MMC-UPQC prototype is introduced, including the overall framework of the control system, the design of the system control layer and the communication system.