Wide-voltage and wide-frequency output plasma power supply and control method thereof

Abstract

The invention discloses a wide-voltage AND wide-frequency output plasma power supply and a control method thereof. the wide-voltage AND wide-frequency output plasma power supply comprises a three-phase rectification circuit, a double-tube buck-boost circuit and a full-bridge inversion circuit,the three-phase rectifier circuit is composed of a three-phase diode rectifier bridge, the double-tube buck-boost circuit is composed of a first switch tube, a second switch tube, a first inductor, a first diode, a second diode and a second capacitor, and the full-bridge inverter circuit is composed of a third switch tube, a fourth switch tube, a fifth switch tube, a sixth switch tube, a second inductor, a third capacitor and a boosting transformer. A direct current voltage and current signal output by the double-tube buck-boost circuit is sampled and adjusted through a controller, so that closed-loop control of output voltage or power of the power supply is realized; and the controller is used for sampling and adjusting a phase signal of alternating current voltage output by the full-bridge inverter circuit, and closed-loop control over the output frequency of the power supply is achieved. The output frequency is improved, and meanwhile it is guaranteed that the working frequency of the switching tube is within a proper frequency range.

Description

technical field [0001] The invention relates to the technical field of plasma power supply, in particular to a plasma power supply with wide voltage and wide frequency output and a control method thereof. Background technique [0002] Plasma generators used for surface treatment of fabrics, polymer films and other materials are generally driven by AC resonant power sources, and their loads are capacitive loads, which together form a resonant circuit with transformers and inductors. Power adjustment methods mainly include frequency adjustment control, pulse density adjustment control, multi-level circuit adjustment, etc. [0003] For the application of plasma material surface treatment, at the same power, increasing the frequency can reduce the degree of surface charge dissipation and prolong the plasma life, thereby improving the treatment effect; at the same time, increasing the frequency can also reduce the electric field intensity of the discharge air gap. Small, electro...

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Problems solved by technology

However, when applied to boost output, the amplitude of the full-bridge output square wave is half of that of the traditional modulation method. If the design of the high-voltage side of the transformer winding remains unchanged, the transformation ratio of the transformer winding needs to be doubled, and the number of turns of the low-voltage side winding should be reduced. half, resulting in twice the peak current of the low-voltage side, and the current stress of the switch tube is greatly increased

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