SU748777A1 - Device for regulating synchronous motor excitation - Google Patents

Description

(54) DEVICE TO REGULATE RETURNING

one

The invention relates to electrical engineering, in particular, to the technique of regulating electric machines, and can be used to control and excite synchronous motors of electric frequency inverters.

In modern power engineering, electric machine frequency converters are used to convert electric current of industrial frequency into electric current of increased frequency, consisting of a high frequency generator and a synchronous or asynchronous drive motor M. five

However, these devices, as well as devices for controlling the excitation of a synchronous motor, for example, in the function of maintaining a reactive current, the power factor a, or 20 voltages of the C2 network, do not ensure the stable operation of synchronous motors as part of electric frequency inverters.

Of the known devices, the most close to the technical essence of the invention is the device 2} for controlling the excitation of a synchronous engine connected to a generator and a network, containing yr-jo sensors of a SYNCHRONOUS MOTOR

between the voltages and the EMF of the engine and the generator, connected by inputs to the excitation regulators of the engine and the generator, respectively, as well as differentiation units connected by the inputs to these sensors, and the outputs to the corresponding excitation regulators.

The specified device regulates the excitation of a synchronous motor by changing the angle 9 between the voltage and the EMF of the motor.

Regulation of the synchronous motor excitation by angle 0 and also by its derivatives allows to increase the stability of the synchronous motor under shock loads, but does not ensure the stability of the synchronous motor as part of an electric frequency converter operating at a sharply variable or synchronous load, since the magnitudes of angles and va between the voltage and the emf of the generator and the motor, and with an equal change in the angles and electrical degrees, it changes the change in er

performance

fe- Pb (where. ,, „

- current frequency - network frequency.

generator as well

powering the motor), which leads to

the overshoot of motor excitation and, accordingly, to the significant fluctuations in the active capacity of the engine and generator.

The purpose of the invention is to increase the speed of the device and engine stability.

This goal is achieved in that the device for controlling the excitation of a synchronous motor connected to a synchronous generator has a greater number of pole pairs than a motor that contains angle sensors between a voltage and an emf of an engine and a generator connected by inputs to the excitation regulators of the engine, respectively. and generator a - also differentiation units connected by inputs with said sensors, outputs with corresponding excitation controllers, according to the invention, the output of the angle sensor between and EMF voltage generator and an output of the differentiating block of the angle v connected to the input of the regulator drive motor.

The drawing shows a block diagram of a device for regulating the excitation of a synchronous motor.

A synchronous motor 1 with excitation regulator 2, powered from mains 3, rotates a synchronous generator of increased frequency 4 having an excitation regulator 5 and feeding the load 6. From the 7 and 8 angles between the voltage and the emf of the motor and generator blocks 9 and 10 of differentiation of these angles, respectively, signals are sent to the excitation controller 2 of the engine. The signals from sensor 8 and differentiation unit 10 are also fed to the excitation controller 5 of the generator.

The regulation of the excitation of the syngron engine is carried out by stabilizing the specified angle b between the voltage and the emf of the gate with correction by changing the angle, Qf - between the voltage and the emf of the hesitator.

V In this case, in the event of a change in load, the excitation of the engine is controlled as a function of maintaining a given y; the head between the voltage and the emf of the engine within

in abg

depending on the sign

load change. Correction of changes in the internal angle bg of the generator improves the accuracy of maintaining the specified angle 6 | engine In addition, .1 the measurement of the angle O can be made in ||| tt times h: more than Sj. which increases the speed of the excitation controller and the engine.

The use of this device for controlling the excitation of a synchronous motor of the frequency converter will allow:

a) increase the load factor of the converter,

b) widely used in frequency converters synchronous motors instead of asynchronous motors, which will give a significant economic effect in the national economy due to the increased power factor and, consequently, energy savings.

Claims (2)

1. Electric machines of alternating current. L., Energie, 1974, p. 88-93. 2.Pep Lin D.P. Automatic regulation of the excitation of synchronous motors, M.,. Gosenergoizdatg 1961, 44-54 fig. 17 (prototype).