Design of a FPGA-based Inverter Drive for HF Injection Based Sensorless Control

This paper presents the design of a Field Programmable Gate Array-based three-phase inverter intended for High-Frequency Injection as used with Low-speed Sensorless Control. Sensorless control includes a wide range of techniques used to control electrical machines without having a dedicated speed or position sensor. Several state-of-the-art techniques use High-Frequency Injection to obtain measurable HF currents which are position modulated.In this paper, a custom inverter was designed for use with an FPGA-based controller which generates both fundamental and High-Frequency rotating sinusoidal components. The use of an FPGA is recommended to increase both the HF signal and Pulse Width Modulation frequency to reduce acoustic noise and torque ripple. Experimental FPGA-based V/f control of a 12 V 400 W Permanent Magnet Synchronous Machine is described. Experimental phase fundamental and High-Frequency current results with different reference frequency setpoints are shown in both time and frequency domains.