JPS6348192A - Controller for reluctance motor - Google Patents

Abstract

PURPOSE:To remove ripple component from an output torque waveform and execute stable control, by permitting sine wave current to flow into stator windings. CONSTITUTION:By a comparator 5, command signal is compared with the output signal of a magnetic pole sensor 4, and the deviation signal is fed to a pulse width modulation generating circuit 6. An inverter 1 is controlled by the pulse width modulation generating circuit 6 so that current flowing to the respective windings of the stator 2 of a reluctance motor based on the deviation signal may be sine wave current having the phase difference of 120 degrees. In other words, by permitting the sine wave current to flow to respective phase windings, the peak of torque is smoothly formed, and ripple component is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a reluctance motor control device that reduces upper ripple.

(Prior art) A reluctance motor with gear-like unevenness on the rotor surface is a special type of synchronous motor, and the synchronous torque is a reaction torque generated by using a magnetically anisotropic rotor. is used.

FIG. 3 shows a schematic configuration of a control device for a reluctance motor when the rotor is driven by three-phase stator winding R, S, and T phase currents. In the figure, each phase winding has a control element, for example a transistor T 1 + T 2 *
TM is connected and a predetermined current is passed through it to generate torque.

FIG. 4(a) shows a developed view of the relationship between the stator and the rotor, in which positive and negative torques are generated in the directions of the arrows, respectively, depending on the direction of movement of the rotor. This torque changes in a triangular waveform, for example, when a constant current is passed through the R phase, as shown in FIG. 2(b). Such torque control is performed by detecting the rotor position, comparing it with a reference value, and controlling the current in each phase winding based on the deviation.

FIG. 5 is a diagram showing the relationship between each phase current and the generated torque. Rectangular wave currents having a phase shift of 120 degrees are applied to each phase winding as shown in FIG. 5(a). The generated torque at this time is expressed as shown in FIG. 4(b).

(Problem to be solved by the invention) If the reluctance motor is to be rotated in the forward direction,
There is a problem in that the effective torque in the traveling direction causes torque ripple as shown by the broken line in FIG. 5(e), making stable control impossible. This means that when a rotor position detector is installed to control the motor in a closed loop, with a DC motor or induction motor, the current and torque are proportional no matter where the rotor is, but with a reluctance motor, This is because the rotor has uneven parts, so the strength of the torque increases depending on the rotor position.

The present invention aims to solve the problems of the prior art and provides a reluctance motor control device that can eliminate torque ripple and perform stable control.

(Means for Solving the Problems) The present invention provides a control device for a reluctance motor in which the surface of the rotor has an uneven portion such as a gear AK, and the stator has polyphase windings. a sensor that detects
A comparator that compares a command signal and a detection signal from a sensor and outputs a deviation signal, and calculates a sine wave current of a predetermined phase and a predetermined amplitude from the deviation signal to determine the current to be applied to the stator winding. The present invention provides a reluctance motor control device characterized by comprising arithmetic control means.

(Function) According to the reluctance motor control device of the present invention, the current flowing through the stator winding of the reluctance motor is controlled to a predetermined phase based on the deviation signal obtained by feeding back the rotor position signal and comparing it with the command signal. By setting the current to a sine wave with a predetermined amplitude, ripple components of the output torque waveform can be removed.

(Example) Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows an outline of one embodiment of the present invention, and 1 is an inverter, and this inverter 1 converts a DC voltage into an AC voltage formed by a converter etc. is supplying power. Reference numeral 3 denotes a rotor, the surface of which is formed with concavo-convex portions similar to those of a gear. Reference numeral 4 denotes a magnetic pole sensor using a resolver or the like, and the rotation angle of the rotor 3 is detected by this magnetic pole sensor 4. A comparator 5 compares the command signal with the output signal of the magnetic pole sensor 4 and sends a deviation signal thereof to a pulse width modulation (PWM) generating circuit 6.

This pulse width modulation generation circuit 6 determines the phase and amplitude of the current flowing through each winding of the stator 2 of the reluctance motor based on the deviation signal, drives and controls the inverter 1, and applies a predetermined torque to the reluctance motor. to occur.

In the present invention, the drive current of each phase is replaced with a conventional rectangular wave, and the current of the winding of each phase becomes a sine wave current with a phase difference of 120 degrees, as shown in FIG. 2(a). It is characterized by the fact that it is controlled in this way.

That is, by flowing such a sine wave current to each phase winding,
As shown by the broken line in FIG. 2(b), the triangular torque peak becomes gentle and the ripple component is removed. Furthermore, the ripple components that are not removed can be completely removed by further superimposing several-order harmonic components on the sine wave and energizing each phase stator winding. By storing a value corresponding to the torque ripple in advance in a memory, etc., the ripple component can be removed by simply reading it from the memory when forming each phase current command. .

(Effects of the Invention) As described above, according to the present invention, by flowing a sinusoidal current into the stator winding of a reluctance motor, ripple components can be removed from the output torque waveform, and stable control can be achieved. Note that the ripple component can be completely removed by further superimposing several-order harmonic components on the sine wave and energizing each phase stator winding.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing one embodiment of the present invention, FIGS. 2(a) and (b) are control waveform diagrams in the same embodiment, and FIG.
The figure is an explanatory diagram of the configuration of a conventional device, FIGS. 4(a) and (b) are explanatory diagrams showing the relationship between the stator and rotor, and FIG. 5(a)
, (b), and (c) are waveform diagrams showing torque in each phase. 1... Inverter, 2... Stator, 3... Rotor, 4... Magnetic pole sensor, 5... Comparator, 6... PW
M generation circuit.

Claims (1)

[Claims] In a control device for a reluctance motor having a gear-like unevenness on the surface of a rotor and a multiphase winding on a stator, the control device includes a sensor for detecting the rotation angle of the rotor, and a command signal and a detection signal from the sensor. It comprises a comparator that compares and outputs a deviation signal, and calculation control means that calculates a sine wave current of a predetermined phase and a predetermined amplitude from the deviation signal to determine the current to be applied to the stator winding. A reluctance motor control device characterized by: