Current type medium-frequency digital power supply based on Matrix converter and control method of current type medium-frequency digital power supply

Abstract

The invention discloses a current type medium-frequency digital power supply based on a Matrix converter and a control method of the current type medium-frequency digital power supply. The current type medium-frequency digital power supply comprises a power input module, an analog signal sampling unit, a Matrix converter frequency conversion circuit, a digital signal processor (DSP) control driving circuit, a protection unit and a load output unit. A current signal is sampled by a DSP, the output of a pulse width modulation (PWM) driving signal is controlled by using a tri-state digital hysteresis control algorithm, and direct current power or alternating current power from the power input module can be converted into medium-frequency sine wave current with set frequency through the Matrix converter frequency conversion circuit. Compared with the conventional circuit, the power supply is low in overall power consumption, high in efficiency and low in amplitude, and can be miniaturized. The frequency spectrum of electro-magnetic interference (EMI) noise is scattered.

Description

technical field [0001] The invention relates to the field of digital switching power supplies, in particular to a current-mode intermediate frequency digital power supply based on a Matrix converter and a control method. Background technique [0002] The traditional current-type sine wave modulation circuit often adopts AC-DC-AC conversion. First, the AC input is rectified into 400V DC high voltage, and a large capacitor is added to the DC side for energy storage. Then, the load sine wave current modulation function is realized through the full-bridge circuit SPWM control algorithm. , the disadvantage is that the high-voltage energy storage capacitor has a large volume, and in a high-temperature working environment, the capacitance decreases significantly, which increases the low-frequency ripple of the circuit, which is not conducive to miniaturization design. , The switching loss is relatively large. Since SPWM is controlled by a fixed frequency, the noise frequency genera...

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Problems solved by technology

[0002] The traditional current-type sine wave modulation circuit often adopts AC-DC-AC conversion. First, the AC input is rectified into 400V DC high voltage, and a large capacitor is added to the DC side for energy storage. Then, the load sine wave current modulation function is realized through the full-bridge circuit SPWM control algorithm. The disadvantage is that the high-voltage energy storage capacitor has a large volume. In a high-temperature working environment, the capacitance decreases significantly, which increases the low-frequency ripple of the circuit, which is not conducive to miniaturization design. At the same time, each switch tube of the SPWM modulated full-bridge circuit is in a high-frequency working state , the switching loss is relatively large. Since SPWM is controlled by a fixed frequency, the noise frequency generated by the high-frequency operation of the switching tube is relatively concentrated. The related EMI suppression circuit needs to be precisely designed to reduce CM, DM and total noise interference

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