CN2234663Y

CN2234663Y - DC loop zero voltage switching device

Info

Publication number: CN2234663Y
Application number: CN95239058U
Authority: CN
Inventors: 洪乃刚
Original assignee: HUADONG METALLURGICAL COLLEGE
Current assignee: HUADONG METALLURGICAL COLLEGE
Priority date: 1995-01-18
Filing date: 1995-01-18
Publication date: 1996-09-04
Anticipated expiration: 2005-01-18

Abstract

The utility model discloses a DC loop zero voltage switching device used for a pulse width modulation type inverter. The utility model can provide switching loss for the pulse width modulation type inverter, enhance the switching frequency of the inverter, improve the property of the inverter, and prevent the secondary breakdown phenomenon of a converter switching device by using the principle of active clamp. The utility model can exploit a converter with high performance and without noise by matching with a new generation high-power high-frequency electronic power switch device. The utility model has simple structure, few application device, convenient control and easy realization, the DC loop voltage is not higher than a power supply voltage, and the converter does not need special switching devices with high voltage resistance.

Description

Novel DC circulation layer voltage switch device

The utility model belongs to electric and electronic technical field, is specifically related to a kind of switching device that PWM-type current transformer direct current is realized no-voltage that is used for.

Existing voltage-type current transformer, the direct current loop voltag is constant, the current transformer electronic switch is under high voltage, big electric current operating mode, by certain control sequence break-make, exist the switch power loss, this power consumption increases with the increase of frequency, has limited the raising of current transformer modulating frequency, and is incompatible with the development of high-power high-frequency power electronic device.Proposed a kind of scheme [1] of direct current ring resonance abroad,, made the direct current ring no-voltage occur by the resonance of inductance, condenser network, switch element is switch work when no-voltage, eliminated the switching loss of current transformer, the switching frequency of current transformer can improve, and the performance of current transformer is also improved thereupon.But the direct current loop voltag can reach 2～3 times of supply voltage during this scheme resonance, the converter switches element is threatened, must adopt high withstand voltage switch element, it improves circuit also because circuit is tending towards complicated, control requires high shortcoming, has influenced popularization in actual applications.

The purpose of this utility model is to provide a kind of electronic power switch device that makes can be at the device of switch under the zero-voltage state, and this device can reduce the switching loss of switching device, improves switching frequency.

Direct current circulation layer voltage switch device of the present utility model is mainly by rectifier (1), current transformer (2), filtering capacitor (10), fly-wheel diode (9) with set up that institute such as zero voltage switch device forms on the DC link between current transformer (2) and the filtering capacitor (10).And fly-wheel diode (9) also is connected across on the direct current ring, be further described below in conjunction with accompanying drawing.

Accompanying drawing one is the utility model switching device structural representation.

Wherein 1, rectifier; 2, current transformer; 3, precharge power supply; 4, balance inductance; 5, discharge electronic switch; 6, charging electronic switch; 7, capacitor; 8, current-limiting inductance; 9, fly-wheel diode; 10, filtering capacitor.

Concrete scheme of the present utility model is: set up the zero voltage switch device on the DC link between current transformer (2) and the filtering capacitor (10), this device is formed by being connected on the balance inductance (4) on the DC link, capacitor (7) discharge circuit of discharge electronic switch 5 controls and the pre-charge circuit of charging electronic switch (6) control.And the discharged in series circuit of being made up of discharge electronic switch (5), capacitor (7) and current-limiting inductance (8) is connected across on the direct current ring.Pre-charge circuit is to adopt charging electronic switch (6) and precharge power supply (3) to be connected in parallel on the two ends of capacitor (7) and current-limiting inductance (8) series circuit.The charging polarity of capacitor (7) is opposite with the polarity of voltage direction of DC link.The course of work of this switching device is as follows:

Rectifier 1 and filtering capacitor 10 are formed the DC power supply of current transformer 2, and balance inductance 4 is connected on the current transformer 3 direct current rings, and when no-voltage, balance inductance 4 plays balance rectifier 1 and current transformer 2 voltages.Before the switch element break-make of current transformer 2, through 6 precharge of charging electronic switch, "+" goes up " " to capacitor 7 under the polarity earlier, and when charging to certain voltage, charging electronic switch 6 turn-offs.Trigger 5 conductings of discharge electronic switch in current transformer 2 element switch, capacitor 7 is through fly-wheel diode 9 discharges.It is the tube voltage drop of fly-wheel diode 9 that the fly-wheel diode 9 of conducting has been clamped down on the direct current loop voltag, is close to zero.The time of afterflow of fly-wheel diode 9 promptly is to make the direct current ring keep the time of no-voltage, current transformer 2 open and close processes finish, discharge electronic switch 5 also disconnects, the direct current ring still returns to DC power supply voltage, therefore the direct current loop voltag is not higher than DC power supply voltage, and current transformer 2 is not wanted special high withstand voltage switch element.Discharge electronic switch 5 closes to have no progeny and triggers charging electronic switch 6 again, and capacitor 7 charges once more, for the switch element break-make of next current transformer 2 is prepared.Because this device makes the direct current ring no-voltage occur at current transformer 2 element switch simultaneously, current transformer 2 switch elements can be in break-make under the zero-voltage state, and the switching loss of current transformer 2 is close to zero, and the switching frequency of corresponding current transformer 2 can improve.The switch element of current transformer 2 has also reduced the possibility of second breakdown under zero-voltage state.

Change the parameter and the pre-charge voltage of capacitor 7, can adjust the no-voltage time, the effect of current-limiting inductance 8 is freewheel current of the pre-charge current and the fly-wheel diode 9 of limiting capacitance device 7, and the time of widening no-voltage.The inductance value of current-limiting inductance 8 if current transformer 2 has inherent fly-wheel diode circuit, then can replace the effect of fly-wheel diode 9 less than balance inductance 4.

This device circuit is simple, and used components and parts are few, and controlling party is convenient to realize, is applied to all kinds of PWM-type (PWM) direct-current switch power supply and frequency converter and can reduces or eliminates switching loss.Match with high-power high-frequency switch device of new generation, can develop noiselessness, high performance convertor assembly.Because no switching loss, heat sink size can reduce, and makes the current transformer volume little in light weight.Additional this circuit on existing convertor assembly, switch under zero-voltage state can reduce switching loss equally, prevents the secondary-breakdown phenomenon of switching device, improves the current transformer reliability of operation, so have tangible using value.

Documents [1] D.M.Divan " The resonant dclinkconverter-A new conceptin static powerconverion " IEEETran.appl.1989.25 (2) 317～325

Claims

1, a kind of Novel DC circulation layer voltage switch device, comprise rectifier (1), current transformer (2), filtering capacitor (10), fly-wheel diode (9), it is characterized in that: on the DC link between current transformer (2) and the filtering capacitor (10), set up the zero voltage switch device, this device is by the balance inductance (4) that is connected on the DC link, and the pre-charge circuit of capacitor (7) discharge circuit of discharge electronic switch (5) control and charging electronic switch (6) control is formed.

2, direct current circulation layer voltage switch device according to claim 1 is characterized in that: the discharged in series circuit of being made up of discharge electronic switch (5), capacitor (7) and current-limiting inductance (8) is connected across on the direct current ring.

3, direct current circulation layer voltage switch device according to claim 1 and 2, it is characterized in that: charging electronic switch (6) and precharge power supply (3) are connected in parallel on capacitor (7) and current-limiting inductance (8) series circuit two ends, and the charging polarity of capacitor (7) is opposite with the polarity of voltage direction of DC link.