A Hybrid-Excited Resolver for High-Speed Operation

Accurate rotor position detection is essential for high-speed machine control systems, yet stable rotor position sensors for operations exceeding 30 krpm are lacking. While resolvers are renowned for their structure robustness in highspeed applications, the necessity for high-frequency enveloping during decoding leads to significant measurement errors as speeds increase, thereby restricting their applications in highspeed scenarios. This paper introduces a novel hybrid-excited resolver scheme designed to generate easily decodable signals for high-speed applications. The scheme employs conventional high-frequency voltage excitation at low speeds, and shifts to adjustable direct current excitation beyond a critical speed threshold, during which the resolver produces orthogonal output signals in the form of back-EMF with a consistent amplitude. By eliminating the need for high-frequency signal enveloping, this method enables the resolver to operate at ultra-high speeds without requiring complex structural modifications. Both simulations and experiments corroborate the effectiveness of this approach, validating its potential for practical applications