The Control Technology Research of the Z-source Three-phase Four-bridge Arm Inverter

Abstract

Z-source inverter can boost the voltage of the DC-side, allow the two switches of the same bridge arm conducting at the same time and it has some other advantages. The zero-sequence current flows through the fourth leg of the three-phase four-leg inverter so the three-phase four-leg inverter can work with unbalanced load. This paper presents a Z-source three-phase four-leg inverter which combines a Z-source network with three-phase four-leg inverter. The circuit uses simple SPWM modulation technique and the fourth bridge arm uses fully compensated control method. The inverter can maintain a symmetrical output voltage when the proposed scheme under the unbalanced load.

Two Phase, Three Legs Inverter with Z-Source Input Impedance

“…The last two phase, three legs inverter circuit used with modulation index (m=0.583333), depending on the analysis of Z-source components, the resistive load was (R=20Ω), and input voltage (V in =200v). In this circuit the method used for obtaining shoot-through state is simple boost shoot through control (SBC) [8]- [10]. The block diagram for this control method is as shown in Fig.…”

“…For the traditional V-source(PWM) inverter " ( ) = * 2 " , "equation (10)"shows that the output voltage can be stepped up and down by choosing the appropriate buck-boost factor B B .…”