A novel SVPWM based maximum boost control of Z source inverter in motor drive application

Z source inverter is a promising substitute of traditional VSI or CSI in application of motor drives. Maximum Boost Control is a classic method used with SPWM to control Z source inverter and it is proved to be more suitable to combine the Maximum Boost Control with SVPWM strategy in motor drive application. However, the peak dc-link voltage fluctuation appears when the SVPWM based Maximum Boost Control method is adopted and the fluctuation will make the torque and speed control more difficult. To solve this problem, this paper proposes a novel SVPWM based Maximum Boost Control method. It can calculate the minimum constant shoot-through duty cycle which is enough for motor driving requirement to replace zero vectors with shoot-through vectors to the largest extent but not all. In this way, the peak dc-link voltage not only can decrease to its minimum but still enough value for driving the load motor, which reduces the voltage stress on the inverter switches, but also tends to be more constant, which contributes to improving the torque and speed regulation performance.