JPS5889099A - Speed controller for induction motor - Google Patents

Abstract

PURPOSE:To improve the speed controlling characteristic by detecting as the number of pulses the rotating speed of a motor by detecting means made of a slit disc, thereby accurately detecting the rotating speed of the motor. CONSTITUTION:Slit discs 2, 3 are mounted on a rotor shaft of a main induction motor 1, and photodetectors 4, 5 which optically detect the slit positions of the discs 2, 3 are respectively disposed in the vicinity of the discs. The outputs of photodetectors 4, 5 are inputted to an arithmetic circuit 10. The circuit 10 has multipliers 12, 14, 16 and adders 18I-18 III, thereby obtaining as an output an output voltage synchronized with the secondary voltage of the induction motor. The speed of the motor is controlled based on the output voltage.

Description

[Detailed Description of the Invention] Speed change of a wound induction motor that performs speed control using the super-synchronous Servius method? Regarding the lili age device number.

When controlling an induction motor using the super-synchronous Servius method, the gate signal of the static converter connected to the secondary side of the induction motor must be synchronized with the secondary voltage of the induction motor. Therefore, it is necessary to detect this secondary voltage.

However, the secondary tonnage pressure becomes approximately zero when the induction machine rotates around the synchronous speed, and the voltage cannot be directly extracted. As methods to solve this problem, methods using a Hall element, a method using a photodetector, and a method using a mechanical commutator have been proposed, but in the case of a Hall element, the temperature characteristics Unfortunately, there was the problem that the magnetic field was easily changed by the surrounding magnetic field.Also, if a photodetector was used, a detection section for three phases was required, so the detector output phase was electrically shifted by 120 degrees. I had to.

The present invention aims to eliminate the above-mentioned drawbacks.
, 94111. to achieve this purpose. A special feature is that the rotor of the motor is provided with 4484 means consisting of two slit disks, and the speed is controlled based on the output voltage synchronized with the secondary voltage of the induction motor according to the detected pulse output.

Hereinafter, a dormitory embodiment of the present invention will be described with reference to the accompanying drawings.

The principles of the present invention will be briefly explained in the explanation of its implementation. Now, if the angular velocity of the rotating magnetic field of the induction motor is ω1°, the rotational speed of the rotor is ω8, and the angular velocity of the 2 &' tortoise force is ω8, then...(3) is obtained. Therefore, the control voltage contaminated by the above equations (11, (21, (31i)) can be connected to the secondary side of the induction motor, and quiet speed control can be performed.

FIG. 1 is a circuit block diagram of an induction-motive speed control ill device according to the present invention. 1 is the main conduction motor (hereinafter abbreviated as M), 2.3 is a slit disk attached to the rotor shaft of this IM7, and 4.5 is this slit disk 2.3.
A photodetector is placed near the slit and optically detects the position of the slit. 10 is an arithmetic circuit, and in this arithmetic circuit, 6.2 is a converter that converts optical outputs from the photodetectors 2 and 3 into frequency outputs. 12.14.16 are multipliers each including a pair of multipliers;
181 is the multiplier 14A, 14B.
The adder that performs the addition of the multipliers 16A and 16B is an adder that performs the addition of the multipliers 16A and 16B, and these adders IJ and I8
Cow (tl)B゛) as the 0 output of 1111
, coe(ωB+'; 4 aπ) , coo (
ω, z+4K) is constructed.

FIG. 2 is a block diagram showing the internal configuration of the converter 6.2 and the multipliers 12, 14, and 16.

n' is an up/down counter, 24.24' is a polarity conversion circuit of positive/negative switching amplifiers 26, 26', 28.28' is an analog switch, and X is a voltage dividing circuit. The reset pulse is obtained by the slit disk 2 attached to the rotor shaft of the above-mentioned machine M1, and by changing the position of this disk 2, an output voltage matching the phase of the secondary voltage can be obtained. This output voltage that matches the phase of the secondary voltage (噸ω
2t, cosω, 1) is the power supply voltage (cosω, t, c
os (ω1 is ten π), cos (ω1 is ten π))
The multiplier 12A is configured to satisfy each term on the right side of equations (11, (21, (31).

12B; 14A, 14B: 16-A,
The outputs of multipliers 12A and 12B are added to adder 181, the outputs of multipliers 14 and 14B are added to adder 11J, and the output of multiplier tag16B is added to adder 18H. Then, three-phase output cage pressures coo (thB: ), cos4 (ω11 + π), and cos (ω + π) having the same phase and frequency as the secondary voltage are obtained, respectively.

As explained above, the speed control device for an induction motor according to the present invention is provided with a detection means consisting of two slit disks on one trochanter of the induction motor, and this detection means detects the rotation speed as a pulse number. Since the detection is carried out, there is no distortion of the detected waveform due to the ambient temperature or magnetic field, which occurs when a Hall collector or the like is used, and an output matching the phase of the secondary voltage can always be obtained. Moreover, there is no variation in the detection characteristics of the above-mentioned detection means, and speed control based on accurate detection can be realized.

[Brief explanation of the drawing]

Figure 1 shows the speed control of the zero conduction motor according to the present invention! ! FIG. 2 is a block diagram showing the internal structure of a part of the arithmetic circuit shown in FIG. 1. 1. Induction motor, 2.3... Disc with slit, 6°7
Converter, 10/arithmetic circuit, 12. 14.16 Multiplier, 18■, 18N, 18x Adder. Procedural amendment (voluntary) April 14, 1972 2811 Dear Commissioner of the Japan Patent Office 1, - Indication of the case 1982 Patent Application No. 1185988 2 Name of the invention Speed control device for induction motor 3 Person making the amendment Relationship to the case Applicant (810) Meidensha Co., Ltd. 4, Agent: 1-29 Mei + FF1R, Chuo-ku, Tokyo 104;
) Patent Attorney (6219) Shiga Fujiya 5, Contents of the column correction of the detailed description of the invention subject to amendment (1) VCHe is listed in the 5th true line 6th line of the specification 7' [Optically detected It's a photodetector. '' should be corrected as in the sentence 1' below. "It is a detector that detects. The first stage of detection tb-z is carried out optically, magnetically, or with a Hall element.J(2) Same page 7
Delete the line "light". (3) Delete “optical” in line 7 of the same page. (4) M true 1! 14th line rVmlJfr%; KJK
to correct.

Claims (1)

[Claims] ``(11) In a speed-side a device of an induction motor that operates on the speed If control side using the super-synchronous Serpius method, a detection means consisting of two slit disks is provided in the rotor of the 6-drive motor. , the induction motor is equipped with a control means for controlling the output voltage synchronized with the secondary voltage of the induction motor according to the two types of pulse signals detected by the detection means. Speed control device. (2) The control means calculates a control voltage for three phases by calculating the output voltage and the primary three-phase voltage, and connects this calculation output to the secondary side of the induction motor. 2. A speed braking device for a rust conduction machine according to claim 1, characterized in that the speed braking device includes an arithmetic circuit serving as a brake for a static converter.