నైరూప్య

Design and Testing of PMSM Drive for Automotive Industry

Mr R.G.Shriwastava, Dr. M.B.Diagavane, Dr. S.R.Vaishnav

This paper describes the design and testing of PMSM drive for Automotive Industry. The impact of various circuits is discussed in detail. Permanent magnet synchronous motor is used here with three stator windings for the motor operation. Three supply voltage are obtained with the help of three phase MOSFET bridge inverters. MOSFET bridges are fed with fixed dc voltage which is obtained by rectifying ac voltage available from ac mains with the help of diode bridge. Shunt capacitor filter is used for filtering purpose. Operation of the MOSFET bridge is controlled by the control circuit. Gating pulses required to turn the MOSFET On are obtained from the control circuit. By controlling the frequency of the gating pulses frequency of the output from MOSFET bridge is controlled. Control circuit consists of clock generator counter and EPROM. First data required to generate gating pulses is calculated and is stored in EPROM. This data is outputted at the output of the EPROM by generating the address of the memory location with the help of 4 bit binary ripple counter. Clock input required for the operation of the counter is generated using IC 555 in astable mode. Frequency of the gating signals coming out of EPROM is dependent on the frequency with which addressing is done which is turn dependent on the clock frequency. Thus by varying the clock frequency of gating signal is varied. If frequency of gating signal is varied, then the MOSFET bridge output frequency is also varied. Thus we obtain variable frequency output. Gating signal outputted by EPROM cannot be directly applied to MOSFET bridge as they are very weak. So isolator and driver circuit is used. Necessary isolation of low power control circuit from high power bridge circuit is obtained by using opt isolator. The Experiment results show that by varying the inverter frequency the speed of the motor also gets varied. If the frequency increases the speed of the motor also increases and if the frequency decreases the speed of the motor also decreases. If the frequency is kept constant at particular value, the speed of the motor also remains constant, irrespective of the load.