Three-phase intermediate frequency power supply

Abstract

The invention discloses a three-phase intermediate frequency power supply. The standard voltage of a three-phase external electric network with 380V / 50Hz is input to an industrial frequency transformer after passing through a three-phase fuse, an input contactor and an anti-electromagnetic interference filter, then is input to a three-phase rectifier after isolation and voltage reduction and then is filtered through a constant K type inverted-L-shaped L second-order low-pass filter and a constant K type inverted-L-shaped C second-order low-pass filter after being rectified by a bridge rectifier to obtain the operating direct-current voltage of a major loop; and the direct-current voltage is transmitted to an IGBT switching tube in a high-power conversion module, an auxiliary power supply is used for supplying power for a control loop to generate intermediate frequency as well as an IGBT pulse width modulation control signal, the IGBT switching tube is driven, the direct-current voltage is converted into three-phase intermediate frequency voltage, isolation, integration and regulation are performed on the three-phase intermediate frequency voltage through an output intermediate frequency transformer, and filtering is performed through the second-order low-pass filter to obtain the standard three-phase intermediate frequency sinusoidal voltage output. The three-phase intermediate frequency power supply overcomes the defects of complex control and driving of intermediate frequency power, excessive high power loss, low efficiency, poor wave-shape, unstable frequency and poor reliability as the traditional intermediate frequency power supply adopts serially connected regulating transistors for voltage regulation or adopts a bipolar transistor, an SCR thyristor and a GTO thyristor as the main power tubes.

Description

technical field [0001] The invention relates to an intermediate frequency power supply used in the industrial field, in particular to a highly stable three-phase intermediate frequency power supply suitable for the fields of aerospace, transportation, scientific research, military communication, home appliance electronics, automobile manufacturing, medical and health care, and the like. Background technique [0002] Intermediate frequency power supplies are widely used in aerospace, transportation, scientific research, military communications, home appliances, automobile manufacturing, and medical and health fields. At present, most of the intermediate frequency power supplies widely used in the industrial field adopt the method of intermediate frequency units. The intermediate frequency units have huge equipment, unstable voltage and frequency, and difficult maintenance. With the development of technology and the emergence of high-power devices, many intermediate-frequency ...

AI Technical Summary

Problems solved by technology

However, in the current products, the traditional three-phase intermediate frequency power supply mainly has the following two types: such as figure 1 As shown, one is to use a bipolar transistor as the adjustment tube, and use a bipolar transistor as the main power tube. The disadvantage is that the adjustment tube must work in the linear region, the power loss is too large, and the control , The drive is complicated, the efficiency is not high, the waveform is not good, the frequency is unstable, the overload capacity is poor, and the reliability is poor

like figure 2 As shown, it is another three-phase intermediate frequency power supply currently used, using SCR thyristor as the main power tube. The disadvantages are that the thyristor is used for control, and the driving is complicated, the efficiency is not high, the waveform is not good, the frequency is unstable, and the reliability is poor. defect

Moreover, most of the generation of the intermediate frequency of the above traditional intermediate frequency power supply depends on the RC oscillator or the L, R, C self-resonant oscillation, and the generated frequency is unstable, and it is easy to change with the change of the ambient temperature.

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