Thyristor voltage regulator: description, purpose

The thyristor voltage regulator is a device designed to regulate the speed of the motor. Adjustment occurs as a result of a change in the voltage that is applied to the stator of the motor, and the angle of opening of the thyristors. This method of motor control is called phase control and is a subset of the amplitude control.

The thyristor voltage regulator is structurally implemented with closed and open-loop control systems. The open system is not able to provide a satisfactory quality of the speed control process. Its main purpose is regulation, aimed at obtaining the necessary mode of engine operation in a dynamic process. A thyristor voltage regulator with a closed system is used with speed feedback. This provides stiff motor characteristics in the low-frequency range of rotation.

The thyristor voltage regulator is most effectively used when adjusting the speed and torque in an induction type motor with a phase armature. A symmetrical wiring diagram provides insignificant losses from harmonic currents. High losses in electric circuits with two or four thyristors are determined by an asymmetric voltage in the phases of the drive. The use of thyristor regulators allows you to control the electric drive not only in the case of descent, but also when lifting the load. True, a voltage drop across the stator will cause a decrease in the magnetic flux. This phenomenon at a given moment will cause an increase in the current loss level and, accordingly, the heating will increase. The dimensions of the thyristor regulators are commensurable with the dimensions of the thyristor power converter of the DC motor, they have the same phase control system, which also distorts the mains voltage.

The operation of the regulator can be compared with the operation of a synchronous key, which is located between the source and the load. The key is in the open state in the first half cycle and in the closed one in the second half.

The thyristor voltage regulator of the generator is used to stabilize the potential difference of the machine generators with an increased frequency at a given level in the event of a change in the magnitude and nature of the load. Using voltage regulators generators can improve the quality of control, as well as stabilize the voltage, which leads to increased stability of the technology.

There is another type of device - a digital voltage regulator. It is built on a single-channel principle. Contains valve converter, voltage sensor, load, reference interval device, comparison circuit, control device. Such a voltage regulator can be used to adjust the pressure in ventilation systems where there is a temperature dependence.