SU769692A2 - Electric motor speed stabilizing device - Google Patents

Description

The invention relates to electrical engineering, in particular to stabilized electric drives having a wide range of speed control.

According to the main author. St. No. 498700, there is known 5 a device for stabilizing the speed of an electric motor, comprising a main control loop with a phase misalignment meter, an amplifier, a main motor, a shaper and a speed sensor mounted on a shaft of an auxiliary motor included in an additional closed control loop with a speed sensor, a shaper, an amplifier and a phase mismatch meter 15, the first input of which is also connected to the input of the phase mismatch meter anija, and to a second input - the output of the master oscillator '[1]. 20

A disadvantage of the known device is that it does not allow a wide range of low speed changes, since the speed in the known device is determined only by the difference in the number of speed sensor labels, which is constant.

The aim of the invention is to expand the range of regulation. thirty

This goal is achieved by the fact that a frequency scale converter is connected between the driver and the phase mismatch meter of the main circuit.

The drawing shows the proposed device.

A device for stabilizing the speed of an electric motor comprises a main control loop 1, which includes a phase misalignment meter 2, an amplifier 3, a main motor 4, a driver 5, a frequency scale converter 6 and a speed sensor 7, as well as an additional control loop 8, including a speed sensor 9, shaper 10, amplifier 11, meter 12 phase misalignment, the master oscillator 13 and the auxiliary engine 14.

The auxiliary electrode with the motor 14 operates in synchronous mode, i.e., the frequency of the generator 13 is equal to the frequency of the speed sensor 9. The pulses of the speed sensor 9 serve as feedback signals of the phase stabilization system of the engine 14, the speed of which is set by the generator 13, and also as reference signals for the main circuit 1. The speed sensors 7 and 9 have the same number of marks, and therefore at zero shaft speed motor 4 frequencies from the outputs of the sensors are equal.

The input of the phase disagreement meter 2 of the main circuit 1 is fed by the pulses of the sensor 9 through the reading head 5 of this sensor and the shaper 10, and the pulses of the speed sensor 7 through the reading head of the sensor 7, shaper 5 and the frequency converter 6. As a result of a change in the frequency level 10, a certain frequency difference is recorded by the phase 6 mismatch meter 2, the mismatch signal appears at the output of the converter 6 through the amplifier 3, acting on the main electric motor 4, which starts to rotate the reading head of the sensor 7, thereby eliminating the difference frequencies at the input of the meter 2.

Upon reaching equality 20

L = ^k f _y >

where f _g , f _y are the frequencies at the outputs of the sensors 9 and 7, respectively; ₂ 5 k - coefficient of the frequency scale converter, the electric drive system will come to equilibrium and the electric motor 4 will rotate at the required speed. ₃ θ

It is clear that for k— \ the speed Shod of rotation of the output shaft of the main engine is 0, and for k = N ®ОД - where w _V d is the speed of rotation of the shaft of the auxiliary engine;

N— any number within

M _11ax >N> 0, where Mpax is the maximum coefficient of the converter 6, at which the speed of the main engine is equal to the maximum.

The range of engine speed control is defined as _ Mmsx ~ ΔΛ '’where ΔΝ is the frequency change stage by the inverter 6.

Tests of a drive that practically implements the proposed device showed that in this device a range of 0 = 1000: 1 can be achieved with high uniformity of rotation and accuracy of maintaining a given speed level.

Claims (2)

motor shaft speeds 4 frequencies from the outputs of the sensors are equal. The input of the phase difference meter 2 of the main circuit I is supplied by the pulses of the sensor 9 through the reading head of this sensor and the driver 10, and the pulses of the speed sensor 7 through the reading head of the sensor 7, the driver 5 and the frequency scale converter 6. As a result of a change in the frequency level of the converter 6, a phase difference meter 2 registers a certain frequency difference. The output of the converter 6 is the error signal through the amplifier 3, acting on the main motor 4, which begins to rotate the read head of sensor 7, thereby eliminating the frequency difference by inlet meter 2. Upon reaching equality Jg / y where fg, fy are the frequencies at the outputs of sensors 9 and 7, respectively; k is the coefficient of the frequency scale converter b, the system of the electric drive will come into balance and the electric motor 4 will rotate at the required speed. It is clear that at & A: the speed of cood rotation of the output shaft of the main engine is O, and for k N Nod // (hell, where "ib is the speed of rotation of the auxiliary motor shaft; N is any number within, where Lschah is the maximum coefficient of converter 6, in which the speed of the main engine is equal to the maximum. The range of engine speed regulation is defined as rj maif DL where AL is the step of frequency variation by converter 6. Testing the drive, practically implementing the proposed device, showed that in this device A range of 1000: 1 will be achieved with a high uniformity of rotation and an accuracy of maintaining a given speed level. The invention The device for stabilizing the speed of an electric motor according to ed. St. No. 498700, characterized in that, in order to expand the control range, a frequency scale converter is included between the driver and the phase difference meter of the main circuit. Sources of information taken into account during the examination 1. USSR Author's Certificate No. 498700, cl. H 02R 5/06, 1972 (prototype).