Shrink Motor Drives for eBikes and Drones
Sep 18, 2022
GaN is a game changer for motor drive applications. For designers to take advantage of this technology, fast and reliable time-to-market is critical. Easy-to-use reference designs using state-of-the-art electronics and techniques provide a valuable tool to speed time to market. The EPC9173 tool allows designers of eBikes and drones to enhance motor system size, performance, range, precision, and torque, all while simplifying design for faster time-to-market.
The EPC9173 integrates all the necessary circuits to operate a 3-phase BLDC motor with high performance, 48 V input, 1.5kW output, and three-phase inverter using six EPC23101 GaN ICs. Thanks to the high-power density and the high electrical conductivity of GaN ICs, the EPC9173 delivers up to 25 ARMS on each leg and supports PWM switching frequencies up to 250 kHz under a natural convection passive heatsink. The resultant quality of the current output waveforms, lesser torque oscillations, and total system efficiency increase the performance of the motor-drive system. Further, the extremely small size of this inverter allows integration into the motor housing resulting in the lowest EMI, highest density, and lowest weight.
The EPC23101 GaN IC featured in this design has exceptionally high electron mobility and a low-temperature coefficient. The lateral structure of the GaN device and the absence of an intrinsic body diode provide a very low gate charge (QG) and zero reverse recovery charge (QRR) when operated in reverse conduction. Compared to MOSFETs with similar RDS(on), GaN FETs have five times smaller switching losses, so the inverter can operate at higher PWM frequency and with shorter dead times. High PWM frequency allows the use of cost-effective ceramic capacitors in the DC-Link, increasing reliability and decreasing cost and size. Short dead times increase the motor efficiency, helping obtain more torque per Ampere RMS.
The EPC9173 inverter reference design board includes all the circuits required to support a complete inverter for e-bike motor drive, including:
- Three-phase inverter based on six EPC23101 GaN ICs
- DC link capacitors
- Regulated auxiliary power supplies
- Voltage, current, and temperature sensors with conditioning circuits
- Protection functions
For a jump start to a highly efficient 3-phase BLDC 48 V motor, check out the EPC9173 reference design, and get your e-bike on the market fast!
For additional information, read the application note, How to Design an eBike Motor Drive Inverter Using EPC9173 Evaluation Board