I'm designing power electronics for 3-phase 3 kW SR motor by using power MOSFETS of rating 600V. To drive the gates of these MOSFETS, I'm using IR2183 gate drivers, one per each phase.

The DC voltage at the drain of MOSFET is directly from the DC capacitor link which supplies 300 VDC.

Although the gate drivers should be in closed loop control system, for simulation purposes I’m using voltage sources for input pulses.

I have provided the circuit diagram and simulation results below. My question is, is this how the output current of an each phase looks like? And do I have to make any more changes to the circuit with higher inductance values (considering motor's inductance would be high)?

I would highly appreciate any suggestions provided.

Thanks in advance.

Gate driver to mosfet connection and simulation

circuit diagram of the input of motor


1 Answer 1


The problem you have is the high side driver is a boot-strap type of circuit which relies on the lower switch of a leg pulling LOW to facilitate charging the capacitor for the higher driver. You have an Asymmetric H-Bridge for an SR machine and thus do not have a complete inverter leg.

The voltage swing of the SOURCE of the upper device is not enough to facilitate providing enough charge.

Such boot-strap circuits work for leg's of inverters as the SOURCE will be pulled down to 0V

For now replace the driver with individual floating drivers

  • \$\begingroup\$ Thanks Rob. With your suggestion I used two individual drivers, this time LT1910. It all works well upto 60V supply voltage (Max supply voltage is 60V according to data sheet). My DC link will be having 300VDC. Can I still use LT1910 gate driver for 300VDC supply? And the simulations look good with 300V supply. \$\endgroup\$ Jan 31, 2018 at 12:11

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