An Auxiliary Resonant Commutated Pole Inverter With Voltage-change-Rate-Limiting And Current-Stress-Limiting Capability

In the application of power converter such as motor drive,uninterruptible power supply and renewable energy grid connection,the requirements for the performance and efficiency of the inverter are getting higher and higher.The introduction of soft switching inverter technology can reduce the switching loss of power devices,and can further improve the switching frequency while ensuring high efficiency.Therefore,soft switching technology has become a research hotspots.In many soft switching inverter topologies,the auxiliary resonant commutated pole(ARCP)inverter is widely favored in high-power applications for its three-phase independent control and high voltage utilization.Through the study and research of available auxiliary resonant pole inverters,in order to overcome the complexity of the auxiliary snubber circuit and the coupling of the resonance process of the double auxiliary resonant commutated pole(DARCP)inverter,this thesis proposed a novel ARCP inverter topology.The new topology not only retains the advantages of reliable zero voltage switching(ZVS)turn-off of auxiliary switches,small current stress of the auxiliary snnuber circuit and high conversion efficiency in light load of the modified DARCP inverter,but also realizes the simplification of the auxiliary snnuber circuit and decoupling of the resonance process.The cost of the inverter and the system oscillation caused by the coupling resonance are reduced,and the performance and practicability of the inverter are improved.However,the contradiction between current stress and voltage change rate in the parameter design makes the selection of resonant capacitors limited.When the voltage change rate meets the requirements,the current stress of the circuit can not reach the expected value.In order to eliminate the contradiction between current stress and voltage change rate of the novel ARCP inverter,a modified ARCP inverter with voltage-change-rate-limiting and current-stress-limiting capability is proposed.By adding a set of auxiliary resonant capacitors to limit voltage change rate,the inverter can not only limit the voltage change rate of the switch when turned off,but also make the current stress approximately equal to the load current,which reduces the conduction loss of the auxiliary snubber circuit.In this thesis,the modified DARCP inverter and the novel ARCP inverter are discussed first,and then the commutation process of the inverter is analyzed,the different commutation modes are divided,the operation principle of the novel ARCP inverter is described in detail,and the soft switching realization condition of the circuit,loss analysis and parameter design method are given.Finally,the simulation platform is built by MATLAB/Simulink software to verify the correctness and superiority of the novel ARCP inverter.