원문정보
초록
영어
The synchronous Pulse-Width Modulation (PWM) is quite complex for three-level neutral point-clamped (NPC) inverter. A simple central 60° synchronous modulation method is presented in this paper for three-level NPC inverter used in the multi-mode PWM strategy. For the fundamental voltage command, the switching angle could be real-time calculated based on this modulation method with different carrier frequency ratios. The switching strategy between these modes is discussed for multi-mode PWM. According to this method, a simulation model of the drive system with three-level inverter and induction motor is built. The simulation results at asynchronous modulation, central 60° synchronous modulation and square wave area, show that the output voltage values can meet the requirements with a good symmetry even in the case of low carrier frequency ratio. The smooth switching among different modes is also accomplished with low impulse current.
목차
1. Introduction
2. Central 60° Synchronous Modulation for Three-level Inverters
2.1. Multi-mode PWM for Three-level Inverters
2.2. The Regular-sampled PWM at Low Carrier Frequency Ratio
2.3. Principles of Central 60° Synchronous Modulation and the Calculations of Switching Angles
3. Accomplishment of Central 60° Synchronous Modulation for Three-level Inverters
4. Performance Evaluation by Simulation
5. Conclusions
References