Integrated current regulation for a brushless ECM drive

A method is described for regulating phase currents in a brushless electronically commutated motor (ECM) without the use of any discrete current sensors such as shunts or current transformers. Current feedback information is provided by current sensors integrated into MOS-gated power switches (i.e. MOSFETs and IGFETs), and the current regulation is performed by smart-power gate drive integrated circuits. The scheme provides protection against dangerous fault currents not sensed by conventional bus-shunt configurations. Available power devices and smart-power components make this technique applicable to ECM drives operating at bus supply voltages up to 500 V DC with power ratings from fractional to >10 hp.<
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