Electrical angle detecting apparatus and method, and motor control apparatus
AssigneeToyota Jidosha Kabushiki Kaisha
InventorsSatoshi Koide, Yasutomo Kawabata, Eiji Yamada
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Abstract
An electrical angle detecting apparatus determines an electrical angle θ from voltages Vd, Vq, and currents Id, Iq along a d-axis and a q-axis of a synchronous motor, by using the following expressions: θ=θ(n−1)+k1×ΔId+k2×Σ(ΔId) ΔId=Id(n)−Id(n−1)−t(Vd−R×Id(n−1)+ω×Lq×Iq(n−1))/Ld; ω=(k1×ΔId+k2×Σ(ΔId))/t where (n−1) indicates a value of each variable at the previous timing; (n) indicates a value at the given timing; R is the resistance of a coil; t is the determination executing period; and k1, k2 are coefficients. This determination makes it easier to set appropriate gains, so that precision improves. Furthermore, the amount of determination reduces, and the processing time shortens.
Claims13
An electrical angle detecting apparatus that detects an electrical angle that indicates an electrical rotational position of a rotor of a synchronous motor, comprising:
- an electrical angle estimator that estimates an electrical angle of the rotor at a predetermined timing as a model value;
- a voltage applicator that applies a predetermined voltage to a coil of the synchronous motor on a basis of the estimated electrical angle;
- a detector that detects a current that flows through the coil in accordance with the voltage applied thereto, as a magnetizing current in a direction along a magnetic flux of the rotor and a torque current in a direction that is electrically perpendicular to the magnetic flux of the rotor;
- and
- an electrical angle determination device that determines a true value of the electrical angle based on an operation expression employing a single parameter that includes at least a deviation between a value of the magnetizing current detected by the detector and a model value of the magnetizing current determined based on a voltage equation that gives a relationship among a voltage across the coil of the synchronous motor, a current through the coil, and an inductance of the coil.
An electrical angle detecting method for detecting an electrical angle that indicates an electrical rotational position of a rotor of a synchronous motor, comprising the steps of:
- (a) estimating an electrical angle of the rotor at a predetermined timing as a model value;
- (b) applying a predetermined voltage to a coil of the synchronous motor on a basis of the estimated electrical angle;
- (c) detecting a current that flows through the coil in accordance with the voltage applied thereto, as a magnetizing current in a direction along a magnetic flux of the rotor and a torque current in a direction that is electrically perpendicular to the magnetic flux of the rotor;
- and
- (d) determining a true value of the electrical angle based on an operation expression employing a single parameter that includes at least a deviation between a value of the magnetizing current detected by the detector and a model value of the magnetizing current determined based on a voltage equation that gives a relationship among a voltage across the coil of the synchronous motor, a current through the coil, and an inductance of the coil.
A motor control apparatus that detects an electrical angle indicating an electrical rotational position of a rotor of a synchronous motor and, based on the electrical angle, controls the synchronous motor so that the motor operates at a required rotational speed and a required torque, comprising:
- an electrical angle estimator that estimates an electrical angle of the rotor at a predetermined timing as a model value;
- a current controller that achieves a magnetizing current flowing through a coil of the synchronous motor in a direction along a magnetic flux of the rotor and a torque current flowing through the coil in a direction that is electrically perpendicular to the magnetic flux of the rotor, by applying a voltage to the coil of the synchronous motor in accordance with the required torque on a basis of the estimated electrical angle;
- a detector that detects the magnetizing current and the torque current;
- an electrical angle determination device that determines a true value of the electrical angle based on an operation expression employing a single parameter that includes at least a deviation between a value of the magnetizing current detected by the detector and a model value of the magnetizing current determined based on a voltage equation that gives a relationship among a voltage across the coil of the synchronous motor, a current through the coil, and an inductance of the coil;
- and
- a reflector that reflects the true value of the electrical angle determined by the electrical angle determination device in estimation of an electrical angle at a next timing.
Dependencies are inferred from the claim text.