20 kW High Efficiency Three-Phase Motor Drive Inverter

This reference design demonstrates how to use silicon carbide (SiC) MOSFETs to optimize the performance of a motor drive for auxiliary motors in electric vehicles, as well as Heating Ventilation and Air Conditioning (HVAC) and other similar applications. Utilizing SiC MOSFETs for these applications can increase system efficiency, reduce audible noise, and increase power density compared to silicon solutions. Although SiC MOSFETs are capable of achieving very high dv/dt switching transitions, the speed can also be easily controlled with the gate resistor to lower levels that are compatible with standard motor insulation while still achieving lower switching losses than silicon IGBTs.

The Design Accomplishes:

• Peak efficiencies of 99.4%, full load efficiency of 98.9%
• Wide operating voltage range
• Closed-loop sensorless field oriented control

Specifications:

• Input Voltage: 550 – 850 VDC
• Switching Frequency: 16 – 32 kHz
• Nominal RMS Output Voltage: 380 VL-L
• Output Power: 20 kW
• Short circuit protection
• Bus derived auxiliary power supply
• Open loop mode for static testing
• Sensorless FOC for permanent magnet synchronous machine (PMSM)
• CAN interface to PC based user interface