Electrical saver for single-phase motors

Abstract

The electrical saver for single-phase motors comprises a main circuit and a control circuit. The main circuit comprises a bridge rectifier QL1. The single-phase motor is connected in series with the input end of the bridge rectifier. The output end of the bridge rectifier is connected with a first inductor L1 and a transistor T1 in series and a second inductor L2 and a transistor T2 in series. Thecontrol circuit comprises a square-wave oscillator and a frequency regulator. The transistor T1 and the transistor T2 are alternately turned on under the control of the square-wave oscillator. The frequency regulator controls the oscillation frequency of the square-wave oscillator according to the current signal. When the oscillation frequency increases, the terminal voltage of the single-phase motor decreases, and vice versa. The electrical saver has the advantages that the voltage of the single-phase motor is adjusted by the current signal of the motor, the output power of the single-phasemotor is matched with the load, and the waste of electric energy is avoided; During voltage regulation, the first inductor L1 and the second inductor L2 alternately have current passing through them,the current of single-phase motor is continuous, and the harmonic component is small, which can greatly reduce the pollution to the power network.

Description

technical field [0001] The invention relates to a power saver for a single-phase motor. Background technique [0002] When the single-phase motor is no-load or light-loaded, its power factor drops, and the method of step-down can be used to compensate the power factor. The existing single-phase motor power saver generally uses a thyristor. The pass angle realizes voltage regulation to achieve energy saving, but the high-order harmonic components of the motor current are relatively large when using thyristors, which will cause pollution to the power grid. Contents of the invention [0003] Aiming at the deficiencies of the prior art, the present invention proposes a power saver for a single-phase motor, which has good energy-saving effect, and the high-order harmonic component of the current is small when the voltage is adjusted, which can reduce the pollution to the power grid. [0004] The technical solution of the present invention is a power saver for a single-phase mo...

AI Technical Summary

Problems solved by technology

[0002] When the single-phase motor is no-load or light-loaded, its power factor drops, and the method of reducing voltage can be used to compensate the power factor. The existing single-phase motor power saver generally uses a thyristor. The pass angle realizes voltage regulation to achieve energy saving, but using thyristor, the high-order harmonic component of the motor current is relatively large, which will cause pollution to the power grid

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