Shunt Based Ground Fault Protection for Inverters Powered from 100/110Vac Supply Reference Design
TIDA-00439
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Key Document
- Shunt-Based Ground Fault Protection for Inverters (100-/110-V AC) Design Guide (Rev. A)
(PDF 2595 KB)
14 Jul 2015
Description
The TIDA-00439 TI design provides a reference solution for detecting ground fault in inverter based drives. Inverter current is measured on both DC positive and DC negative bus using shunt resistors. INA149 current sense amplifier having common mode voltage range of +275V is being used to measure current on DC Positive bus. Current on DC negative bus is sensed using precision opamp’s. The difference between the two measured currents is compared against a fixed threshold to determine the ground fault condition using high speed comparators.
Features
- Shunt based current sensing for inverter control and protection
- Rated to measure DC Link current of +/-20APK (Design tested for +/-5A)
- High side current sense circuit with high common mode voltage of +275V supporting 100/110Vac mains powered drives
- Calibrated high-side and low-side measurement error over operating temperature range of -10°C to 55°C < 1.5%
- Ground fault: (Minimum fault current detection of 300mA, Detection time of less than 50µs)
- Designed to be interfaced with built-in 3.3V ADC of MCU
See the Important Notice and Disclaimer covering reference designs and other TI resources.