Digital phase-shift circuit and improved AC (Alternating Current) power source thereof

Abstract

The invention discloses a digital phase-shift circuit in the technical field of a power system. The digital phase-shift circuit comprises a counting, triggering and frequency dividing unit, a short circuit pulse counting unit and an over-current pulse counting unit. An improved AC power source including the digital phase-shift circuit comprises a main loop and a control loop which is connected with the main loop and transmits a work state and a control command; the main loop comprises an input filter, an AC-DC voltage adjusting circuit, a DC filter, a DC-AC converter and an output filter, all of which are connected sequentially; and the control loop comprises a variable frequency trigger circuit, a man-machine interaction module and the digital phase-shift circuit according to any one of claims 1 to 3. The digital phase-shift circuit, disclosed by the invention, solves the problems of output waveform distortion, small frequency adjustment range, influence to input power source, complex circuit and the like of the conventional voltage adjusting and frequency adjusting power source which adopts a thyristor voltage adjusting circuit.

Description

technical field [0001] The invention relates to a device in the field of power system technology, in particular to a digital phase shifting circuit and its improved AC power supply. Background technique [0002] At present, the voltage regulation of AC power supply is mainly realized by the thyristor, and the output waveform of the thyristor is generally distorted in the process of AC voltage regulation, and the harmonic interference is serious. The reason is that the control pole of the thyristor can only Trigger conduction, and after conduction, only when the current of the thyristor is less than the minimum value for maintaining conduction can it be shut down in the AC power supply and automatically shut down at zero crossing. [0003] Due to the low frequency, it is difficult to deal with sine wave AC power. Therefore, the thyristor can only adjust the voltage of the sine wave AC power supply by triggering the conduction in the corresponding phase angle, which leads to ...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the above-mentioned deficiencies in the prior art, the present invention provides a digital phase-shifting circuit and its improved AC power supply, which is based on large-scale programmable logic chip control and adopts special DDS synthesis waveform technology for sine wave frequency modulation and voltage modulation AC power supply, which solves the current problem The voltage-regulated and frequency-regulated power supply uses the output waveform distortion of the thyristor voltage regulating circuit, and the frequency can only be adjusted in a small range, which will interfere with the input power supply and the circuit is complicated.

Images