US 5,140,245 A · PMG-based position sensor and synchronous drive incorporating same

Abstract

A multiphased permanent magnet generator (PMG) driven by a rotating shaft, generates a multiphase output which is integrated and applied as the input to a high resolution phase locked loop having a binary counter with an output phase locked to the PMG multiphase output and representing shaft position. As applied to a high performance synchronous drive in which the PMG is driven by the synchronous machine, the digital shaft position signal is used to generate a multiphase current reference signal which is tracked by stator currents generated for the synchronous machine by a power current source. The multiphase current reference signal can be generated by a selected set of multiphase digital sine waveforms stored in a ROM which is part of the phase locked loop or is a separate waveform synthesizer.

Claims22

Dependent claims

An absolute angular position sensor for a rotating shaft, comprising:

a multiphase permanent magnet generator connected to said rotating shaft and generating a multiphase signal having a phase determined by the angular position of said shaft;
means integrating the multiphase signal generated by said permanent magnet generator to generate an integrated multiphase signal;
means generating a rotating shaft angular position signal from said integrated multiphase signal;
and
validity indicating means monitoring said integrated multiphase signal and generating a validity signal indicating said rotating shaft angular position signal is valid once said integrated multiphase signal has a magnitude above a pre-selected value.

2 more elements

A control system for multiphase synchronous machine having a rotor and a multiphase stator winding, said system comprising:

a permanent magnet generator (PMG) coupled to said rotor and generating a multiphase PMG signal having a phase determined by the angular position of said rotor of the synchronous machine;
means integrating the multiphase PMG signal to generate an integrated multiphase PMG signal;
rotor position sensing means generating a rotor angular position signal from said integrated multiphase PMG signal;
validity indicating means monitoring said integrated multi-phase PMG signal and generating a validity signal indicating said rotor angular position signal is valid once said integrated multiphase PMG signal has a magnitude above a pre-selected value;
current reference signal generating means generating a multiphase current reference signal having a selected phase relationship to said rotor angular position signal;
and
power current source means generating currents int he multi-phase stator winding having phases which track said multiphase current reference signal and an amplitude determined by said multiphase current reference signal.

4 more elements

Dependencies are inferred from the claim text.

PMG-based position sensor and synchronous drive incorporating same

Life of this patent

PMG-based position sensor and synchronous drive incorporating same

Life of this patent

Abstract

Claims22