Study On Three-Level Back-to-Back Power Converter

Along with the increasing demand for in the field of high power of modern industry and promote the rapid development of multilevel converter, the three-level converter topology structure is relatively simple, network side power factor high(the highest under unity power factor operation), the pollution to the power grid caused by decreased greatly, and the switch should stress more advantages. In the rapid development of modern industry, three-level converter have become a research hotspot in the field of high voltage power frequency.In this dissertation, the diode clamped three-level topology as the main circuit of the system, for the back-to-back three-level power converter, three-level rectifier using PWM rectifier control technology, through the feedforward decoupling control strategy to realize the control of grid side signal, to run on a single power factor under the system, and ensure the DC voltage rectifier output with a given system reference value; for the fluctuation of the neutral point potential in DC side diode clamped three level topology of the proposed in hysteresis loop control mode to achieve voltage control strategy of DC side neutral point potential; the three-level inverter in back-to-back power converter system. This paper is the use of SVPWM modulation based on open loop control.This dissertation builds the three-level rectifier system simulation module and three-level inverter system simulation model with MATLAB / Simulink software of back-to-back system, the system is verified by simulation at the same time the realization of SVPWM is analyzed and DC side capacitor neutral point balance control scheme is verified by simulation based on hysteresis control method. TI’s TMS320F2812 DSP is used as the system main control chip for software design and the hardware circuit design is though a system experimental platform, this method is verified the correctness and feasibility of the system with simulation and experimental results.