| With the continuous improvement of the performance of high-power power electronic devices,inverters are widely used in various fields that require energy transmission.Traditional voltage-type inverters and current-type inverters have been gradually eliminated due to their r espective functional defects.The Z-source inverter has an output side voltage higher than the input side voltage due to the addition of the energy storage element in its topology.The Z-source inverter is widely used in photovoltaic power generation syste m grid-connected,AC motor drive system,UPS power supply and other fields due to the increase of the output side voltage and the simultaneous conduction of the inverter bridge arm IGBT switch tube.However,the Z source inverter has limited boosting capability,intermittent current on the input side,and large capacitance voltage stress in the impedance network.In view of the shortcomings of Z-source inverter,this paper proposes an improved quasi-Z source inverter(SB/SL-q ZSI)topology structure,and analyzes its topology through-state and nonthrough-state working principle in detail,and calculates.according to theoretical analysis.Compared with the traditional Z-source inverter.The SB/SL-q ZSI has a wide range of boosting capabilities.The SB/SL-q ZSI inverter bridge IGBT switching tube trigger pulse is designed,and the improved SVPWM pulse modulation strategy is proposed.The traditional SVPWM space vector pulse 6-section straight-through vector is integrated into 4 segments to reduce the inductor curren t ripple and improve the output.Voltage gain.The small-signal model of SB/SL-q ZSI is built,and the influence of inductance and capacitance parameters on the stability of SB/SL-q ZSI system in impedance network is analyzed.The capacitor voltage constant-voltage closed-loop control strategy is designed to ensure that the capacitor voltage in the SB/SL-q ZSI impedance network is stable,which not only reduces the IGBT switching voltage stress,but also ensures stable operation of the system.The SB/SL-q ZSI output voltage simulation model was built on the MATLAB/Simulink simulation platform,The SVPWM pulse trigger model was improved,the capacitor voltage constant control model of the input side voltage drop was applied,and the SB/SL-q ZSI topology was verified by the simulation waveform.The correctness of the trigger pulse and capacitor constant voltage control strategy.The SB/SL-q ZSI output voltage simulation model was built on the MATLAB/Simulink simulation platform,The SVPWM pulse trigger model was improved,the capacitor voltage constant control model of the input side voltage drop was applied,and the SB/SL-q ZSI topology was verified by the simulation waveform.The correctness of the trigger pulse and capacitor constant voltage control strategy.Through the detailed calculation of SB/SL-q ZSI topology parameters and hardware design,the SB/SL-q ZSI prototype test platform with TMS320F28335 as the core is built.The input DC voltage is successfully driven to drive the effective value to the rated speed of the three-phase asynchronous motor.The output voltage experimental waveform is recorded and compared with the theoretical value.The overall data error is within 10%,and the correctness of SB/SL-q ZSI is verified. |
