Abstract: Shared inverter can simplify the topology of the dual machines drive system under the traditional axis

control mode，reduce the volume and weight of the equipment. In view of the low voltage utilization rate of a single motor in the shared inverter drive system，which leads to the shortening of the constant power area of motor traction characteristics and the difficulty in realizing high-power output，a new Z-source nine switch（ZS9）dual permanent magnet synchronous machine（PMSM）drive system of shared inverter was studied. The constant torque and field weakening control strategy of dual machines were studied by using the time-sharing control principle，according to the principle of seven segment space vector pulse width modulation（SVPWM），the optimal switching sequence and the generation and distribution method of Z-source shoot-through zero vector were studied，the indirect voltage method was used to control the Z-source voltage. A variety of operating conditions were simulated by off-line and hardware in the loop，the experimental results show that the dual machines in the shared inverter drive system can be controlled independently，which can meet the needs of practical engineering applications.

      Key words: shared inverter；Z-source；permanent magnet synchronous machine（PMSM）；time-sharing control；shoot-through zero vector