Research On Multi-modal Combination PWM Control Of Impedance Source Boost Inverter

Impedance source step-up inverter is obtained by applying impedance source step-up network to DC-AC converters.It overcomes the deficiencies of the traditional voltage source inverter.Therefore,it is widely used in new energy generation system,uninterruptible power supply and electric vehicle.Quasi-switched boost inverter uses a switched boost impedance network to replace Z-source impedance network,which also has the good characteristics of the Z-source inverter and smaller volume,in order to get the best performance control strategies.The main contents of this paper are as follows:Firstly,this paper summarizes the control methods of the quasi-switched boost inverter,in which the inverter bridge inherit the PWM control methods of the impedance source boost inverter,and the control methods of the active switch in the switched boost impedance network are as follows: 1 The conduction of active switch is fully synchronized with the shoot-through of the inverter bridge;2 The conduction of active switch is not fully synchronized with the shoot-through of the inverter bridge;3 The conduction of active switch is staggered with the shoot-through of the inverter bridge.Secondly,the operating characteristics of the switched boost inverter under the above three control methods are analyzed in detail,and it is found that the control methods of the quasiswitched boost inverter can be obtained by combining different operating modes,so according to the principle of volt-second balance of inductor,this paper proposes a multi-modal combination method.Thirdly,the proposed multi-modal combination method is applied to two kinds of quasiswitched boost inverters(single-phase quasi-switched boost inverter and single-phase high voltage gain quasi-switched boost inverter)respectively,and all of their feasible multi-modal combined PWM control methods are obtained.The operating principle and characteristics of the above two-mode,three-mode and four-mode combined control strategies are analyzed in detail,and compared with the existing control methods in detail,highlighting the advantages of the proposed control method.Simulation and experimental results verify the correctness of the theoretical analysis.