High power pulse load power soft start device and starting method

Abstract

The invention discloses a high power pulse load power soft start device and a starting method; the high power pulse load power soft start device comprises a MOS tube Q1, a MOS tube Q2, a MOS tube Q1 control device and a MOS tube Q2 control device, wherein the MOS tube Q2 control device comprises a voltage sampling circuit, a comparator and a driver circuit, which are connected in sequence; the voltage sampling circuit comprises a resistor RS1 and a resistor RS2; the resistor RS1 and the resistor RS2 are connected in series and then are connected to two ends of an energy-storage capacitor C; the input end of the comparator is connected between the resistors RS1 and RS2; the drain electrode of the MOS tube Q2 is connected to one end of the energy-storage capacitor, and the source electrodeis connected to the negative pole of a direct-current bus; the MOS tube Q1 control device comprises resistors R1, R2, R3 and a direct-current power supply; the drain electrode of the MOS tube Q1 is connected to one end of the energy-storage capacitor, the source electrode is connected to the cathode of the direct-current bus through the resistor R1, and the grid electrode is connected to the direct-current power source through the resistor R2; and the grid electrod3 of the MOS tube Q1 is also connected to the cathode of the direct-current bus through the resistor R3. The high power pulse loadpower soft start device and the starting method in the invention has good surge current suppression effect, simple circuit and small loss, and is suitable for high power applications.

Description

technical field [0001] The invention relates to a soft start device for a power supply, in particular to a soft start device and a start method for a high-power pulse load power supply. Background technique [0002] The output signal of electronic countermeasure equipment generally has a wide frequency band and pulse change characteristics, which put forward higher requirements for the stability of its generator power supply; when the pulse power of electronic countermeasure equipment changes, the existing technology adopts the method of adding a Large-capacity energy storage capacitors are used to absorb the slope of pulse power changes of electronic countermeasure equipment; but when using this method to power the DC bus, since the energy storage capacitors are in the initial state that has not yet been charged, a large amount of power will be generated at the moment the switch is turned on Large inrush current; the inrush current may cause two problems: first, if the DC p...

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Problems solved by technology

[0002] The output signal of electronic countermeasure equipment generally has a wide frequency band and pulse variation characteristics, which put forward higher requirements for the stability of its generator power supply; when the pulse power of electronic countermeasure equipment changes, the existing technology adopts the method of adding a Large-capacity energy storage capacitors are used to absorb the slope of electronic countermeasure equipment pulse power changes; however, when using this method to power the DC bus, since the energy storage capacitors are in the initial state that has not been charged, a large amount of power will be generated at the moment the switch is turned on Large inrush current; the inrush current may cause two problems: first, if the DC power supply cannot supply enough starting current, the switching power supply may enter a locked state and cannot be started; second, this inrush current It may cause a drop in the input power supply voltage, which is enough to cause instantaneous power failure of other starting devices using the same input power supply; therefore, it is very necessary to soft start the circuit when the DC bus is connected

[0003] The traditional surge suppression circuit solution is to directly connect a thermistor with negative temperature characteristics in series on the power supply line between the power supply bus and the energy storage capacitor. The principle of this method is: when the power supply switch is turned on, the thermal resistor with negative temperature coefficient The thermistor has a high impedance at the moment of starting up; after suppressing the surge current by using its own high impedance characteristic, as the switching power supply enters the normal working state, the thermistor will generate self-heating phenomenon, and according to the negative temperature coefficient characteristic, its resistance value will also change with the Therefore, the power loss problem under normal working conditions is greatly reduced and the inrush current value is effectively reduced; but the limitation of this method is that after the inrush current suppression is completed, the thermistor works for a period of time in the switching power supply After self-heating, the resistance value decreases. At this time, if the switching power supply is shut down and restarted immediately, the phenomenon of inrush current suppression failure will occur.

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