Rotor Position Calculation in Case of Partial Failure of Resolver for Motor Control Application

Rotor position sensing in motor control applications ensures precise feedback for accurate rotor movement, efficiency, and safe operation of Permanent Magnet Synchronous Motors (PMSMs). Resolvers without electronic components are widely used in motor control systems because of their resistance to soiling, vibration, and extreme temperatures, along with their ability to provide continuous position feedback. However, rotor position is calculated using multiple output signals from resolvers, and loss of one or more output signals may lead to inaccurate position sensing thereby impacting motor operation. This paper introduces a novel strategy of rotor position calculation using frequency and phase equalization of remaining output signals, in case of partial resolver failure. The proposed method serves as an alternate method to measure the accurate and robust position, and speed of the rotor, ensuring continuous motor operation.