Working principle of three-phase voltage regulator

The working principle of a three-phase voltage regulator involves voltage detection, adjustment mechanisms, and output feedback. Voltage detection monitors the input voltage in real time using sensors. Adjustment mechanisms include servo motor control (mechanical), which adjusts the output voltage by moving the transformer windings with carbon brushes, and electronic mechanisms (such as SCR thyristors), which use power electronic devices to quickly switch transformer taps to achieve contactless voltage regulation. Output feedback outputs the adjusted stable voltage to the load, forming a closed-loop control to ensure stable output voltage.

To address three-phase voltage imbalance, a three-phase voltage regulator can be equipped with a three-phase balancing device (SPZ). This device includes a three-phase four-wire input section and three single-phase transformers, balancing the output voltage of each phase to ensure basic three-phase power balance.

Furthermore, contactless inductive voltage regulators utilize induction principles for linear voltage adjustment. The contactless design avoids noise coupling, and technologies such as double-layer lapped coils are employed to maintain voltage stability even when the load current imbalance is 0.5%.