High-frequency modulation motor position detection device

Abstract

The invention relates to a high-frequency modulation motor position detection device, which at least comprises a high-frequency excitation circuit, a sensing element and a demodulation and calculation circuit, and is characterized in that the high-frequency excitation circuit realizes narrowband alternating voltage excitation of a specific carrier frequency of the sensing element; the sensing element at least comprises a transmitting coil, a receiving coil and a feedback coil, the transmitting coil and the receiving coil are fixedly connected with a motor stator, the feedback coil is fixedly connected with a motor rotor, and the transmitting coil, the feedback coil and the receiving coil work in a resonance state under the action of specific carrier frequency narrow-band alternating voltage excitation; and the demodulation and calculation circuit detects a resonance voltage signal of the receiving coil to realize demodulation of a motor position signal. Compared with the prior art, the invention makes full use of the technical characteristics of high-frequency modulation, and has the advantages of small switching loss of a high-frequency excitation circuit, large load impedance range in the optimal working state, good frequency selectivity of a sensing element, strong anti-interference performance, high high-frequency processing speed of a demodulation and calculation part, good noise immunity and the like.

Description

technical field [0001] The invention belongs to the technical field of position detection and measurement, and relates to a motor position detection device, in particular to a high-frequency modulation motor position detection device, which can also be used for other non-contact position detection. Background technique [0002] The acquisition of rotor position information plays a vital role in the motor control system, and its sensing accuracy directly affects the efficiency, actual torque and maximum speed of motor control. [0003] In the current motor position detection, the resolver is one of the most important forms, such as figure 1 shown. Taking a common reluctance resolver as an example, generally one primary excitation winding and several (generally two sine and cosine) secondary detection windings are set, and the magnetic permeability between the excitation winding and detection winding changes with the change of the motor rotor , thereby causing a change in th...

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Problems solved by technology

[0006] 2) The winding of the coil has inhomogeneity;

[0007] 3) The carrier frequency is up to 20kHz, and the solution bandwidth limits the position dynamic response at high speed;

But this invention does not give how to realize the excitation circuit and the demodulation and calculation circuit, and because the traditional position sensing excitation and detection circuit cannot be directly used, so the aforementioned scheme is incomplete and cannot give full play to the effectiveness of the detection principle; at the same time, the invention also The equivalent impedance of the sensing element is not constant, and the output envelope signal is not ideal.

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