Thyristor voltage regulator is a device designed to control the speed of an electric motor. Adjustment occurs as a result of a change in voltage, which is connected to the motor stator, and a change in the opening angle of the thyristors. This method of controlling electric motors is called phase control and is a subspecies of amplitude control.
The thyristor voltage regulator is structurally performed with closed and open regulation systems. An open system is not able to provide a satisfactory quality of the speed control process. Its main purpose is adjustment, aimed at obtaining the necessary engine operation mode in a dynamic process. A thyristor closed-circuit voltage regulator is used with speed feedback. This provides tough engine performance in the low-speed range.
The thyristor voltage regulator is most effectively used to control the speed and torque in asynchronous type electric motors with a phase armature. The symmetrical connection scheme provides insignificant losses from harmonic currents. High losses in electrical circuits with two or four thyristors are determined by the 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 decrease in voltage on the stator will result in a decrease in magnetic flux. This phenomenon at this moment will cause an increase in the level of current loss and, accordingly, increase heating. The dimensions of the thyristor regulators are commensurate with the overall dimensions of the thyristor power converter of the DC motor, they have the same phase control system, which also distorts the voltage of the mains.
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 state in the second.
The thyristor voltage regulator of the generator is used to stabilize the potential difference of machine generators with an increased frequency at a given level in case of a change in the magnitude and nature of the load. The use of voltage regulators of 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. It contains a valve converter, a voltage sensor, a load, a reference interval device, a comparison circuit, and a control device. Such a voltage regulator can be used to adjust the pressure in ventilation systems, where there is a dependence on temperature.