CN205844481U - A kind of indicating circuit of serial semiconductor switch short trouble - Google Patents

Abstract

The utility model discloses the indicating circuit of a kind of serial semiconductor switch short trouble, the IGBT switch being integrated including some grades of series connection, described every one-level IGBT switch ends static voltage sharing in parallel, static voltage sharing on described every one-level IGBT switch includes an equalizing resistance connected and auxiliary equalizing resistance, the two ends of a described auxiliary equalizing resistance light emitting diode in parallel；The voltage at described auxiliary equalizing resistance two ends is not less than the forward direction tube voltage drop of Light-Emitting Diode, and the resistance of equalizing resistance is more than the resistance of auxiliary equalizing resistance, and the electric current on described Light-Emitting Diode is not more than the difference between current of equalizing resistance and auxiliary equalizing resistance.By visual method, this utility model only need to increase a resistance and light emitting diode can judge in tandem tap module whether IGBT at different levels are short-circuited fault, circuit is simple and reliable, without dismantling circuit, without extra power supply, it is simple to rapid-maintenance and replacing defective device at the scene.

Description

A kind of indicating circuit of serial semiconductor switch short trouble

Technical field

The present invention relates to technical field of pulse power, be specifically related to a kind of serial semiconductor switch breaker in middle short trouble Indicator light circuit, can not the asking of fault location in time in time solving that switches at different levels are short-circuited in serial semiconductor switch Topic.

Background technology

Pulse Power Techniques are to be discharged rapidly within the extremely short time by the energy stored in relatively long time The science come.Currently, Pulse Power Techniques all obtain in fields such as national defence scientific research project, research in new high-tech and civilian industries To being widely applied very much.In the device producing high power pulse, switch is one of most important parts, and it plays connection energy storage Unit and the effect of load unit.Turn-on and turn-off process due to semiconductor switch relies on the transfer of carrier, and mechanical is touched Point, therefore have can turn off, Gao Zhongying, in advantages such as pressure operated within range voltage range width, in recent years pulse power fill It is widely used in putting.MOSFET (metal oxide semiconductor field effect tube, Metal-Oxide- Semiconductor type Field Effect Transistor) and IGBT (insulated gate bipolar transistor, Insulated Gate Bipolar Transistors) it is main force's semiconductor switch device of modern fast pulse technology development. Along with the development of Power Electronic Technique, its running voltage and operating current are more and more higher, end 2016, and single MOSFET is The most pressure 1.2kV that is about, single the maximum pressure about 6.5kV of IGBT.

In the output application of tens of to up to a hundred kilovolts such high-voltage pulse, single semiconductor switch only pressure far from Meet demand, it is therefore necessary to be used in series, form tandem tap module.When some switches are used in series, can Only switch higher voltage to bear than single, but must assure that in tandem tap module that the voltage that every switch ends is born is basic Equal.Therefore, widely used method is in the equal static voltage sharing of every switch ends parallel connection resistance, the resistance of resistance Much larger than the equivalent internal resistance of switch, the voltage of so every switch ends is substantially equal to the dividing potential drop at static voltage sharing two ends, can Of substantially equal to ensure every switch ends voltage.

But, when real work, due to load end reflection, loop stray parameter, or switch conduction and turn off the moment The reason such as inconsistent all can cause switch that " overvoltage " occur and punch through damage, and is usually expressed as " short-circuit " state.If A certain switch in tandem tap is short-circuited damage, and this switch shows as low impedance path state, may whole string Connection switch module still can normally work, but remaining switch to bear more higher voltage than design load, the most in succession occurred Pressure punch through damage.

For being switched the application scenario formed by single IGBT, can judge that IGBT is easily by multiple testing circuit The no fault that is short-circuited.But in IGBT serial module structure, it is suspended in high potential work owing to every one-level IGBT is substantially, and Current potential is each variant.Such as, in the high-voltage pulse application of output 150kV, if using 100 switch series connection, then open for every Close suspended voltage from 0kV, 1.5kV, 3.0kV ..., be continued until 148.5kV, thus must have 100 groups mutually isolated, and Above earth potential can reach the power supply of corresponding isolation voltage and power to testing circuits at different levels, and high-voltage isolating is powered and inherently gone here and there A difficult problem in connection switch combination application.Therefore those need power supply just workable testing circuit at tandem tap mould Block application brings great complexity to system.For ease of maintenance and use, and it is resistance to avoid carrying out height to testing circuit Pressure isolation power supply, it is possible to be design tandem tap mould by visual method find early the to be short-circuited semiconductor switch of fault A necessary miscellaneous function in block.

Semiconductor switch, including, but not limited to MOSFET and IGBT, illustrates present invention not herein as a example by IGBT Summary of the invention can be produced impact, the most all describe in detail as a example by IGBT.

Paper " failure detection of IGBT high-pressure series assembly and the recovery plan of " Xi'an University of Technology's journal " 2012 Published in China Pharmacies Slightly " propose the open fault using complicated logic circuit to judge IGBT, detect short-circuit condition from the present invention different.By China Patent Office is inquired about, Zhejiang University the patent applied for is " a kind of based on V_CEIGBT short-circuit protection adaptive optimization unit and side Method ", and patent " protection device of power semiconductor switch element and the guarantor applied for by Hitachi of Amada Co., Ltd. Maintaining method " overcurrent protection to IGBT when being all that load short circuits is discussed is not the short trouble of of detection IGBT itself.

Summary of the invention

It is an object of the invention to provide a kind of by visually directly judging serial semiconductor switch module has occurred that The circuit of the switch of short trouble and method.This circuit is on the basis of the tandem tap module original static voltage sharing of every one-level On, increase a resistance and a light emitting diode, by observing whether light emitting diode is illuminated to judge this one-level current Whether semiconductor switch is short-circuited fault.

For achieving the above object, the present invention adopts the following technical scheme that

A kind of indicating circuit of serial semiconductor switch short trouble, the IGBT switch being integrated including some grades of series connection, Described every one-level IGBT switch ends static voltage sharing in parallel, the static voltage sharing on described every one-level IGBT switch Including equalizing resistance and the auxiliary equalizing resistance of a series connection, the two ends of a described auxiliary equalizing resistance light-emitting diodes in parallel Pipe；

The voltage at described auxiliary equalizing resistance two ends is not less than the forward direction tube voltage drop of Light-Emitting Diode, the resistance of equalizing resistance More than the resistance of auxiliary equalizing resistance, the electric current on described Light-Emitting Diode is not more than the electricity of equalizing resistance and auxiliary equalizing resistance It is poor to flow.

In technique scheme, the voltage value of described every one-level IGBT switch ends is equal.

In technique scheme, the resistance of equivalent internal resistance of every one-level IGBT switch more than static voltage sharing resistance value An order of magnitude.

In technique scheme, the resistance of described equalizing resistance is much larger than the resistance of auxiliary equalizing resistance, described auxiliary The resistance of equalizing resistance is not more than the resistance of 0.1 times of equalizing resistance.

The fault judgment method of the indicating circuit of a kind of serial semiconductor switch short trouble, when in series IGBT switch terminals Apply relatively low voltage, it is ensured that voltage makes the light emitting diode of now every one-level switch to be lit, and observes all of luminescence Diode, if some light emitting diode is not lit, then can determine that this one-level corresponding IGBT switch there occurs short circuit Fault.

In sum, owing to have employed technique scheme, the invention has the beneficial effects as follows: the present invention only need to increase by one By visual method, resistance and a light emitting diode can judge in tandem tap module, whether IGBT at different levels occur short Road fault, circuit is simple and reliable, without dismantling circuit, without extra power supply, it is simple to rapid-maintenance and replacing fault device at the scene Part.

Accompanying drawing explanation

Examples of the present invention will be described by way of reference to the accompanying drawings, wherein:

The tandem tap modular circuit schematic diagram that Fig. 1 is made up of IGBT semiconductor switch and static voltage sharing；

Fig. 2 is that the present invention is to the improvement circuit theory diagrams of certain primary unit in tandem tap module.

Detailed description of the invention

The colelctor electrode of a tandem tap module every one-level IGBT switch and emitter-base bandgap grading static voltage sharing generally in parallel；This Bright " main equalizing resistance " and " auxiliary equalizing resistance " two resistant series that static voltage sharing is replaced with, and all press in auxiliary The light emitting diode (LED) of the two ends of a resistance high brightness in parallel.The resistance of main equalizing resistance is much larger than another auxiliary all Piezoresistance, such series resistance still possesses the function of static voltage sharing.When applying certain survey at tandem tap module two ends During examination voltage, every one-level IGBT all bears corresponding dividing potential drop, if IGBT function is normal, then LED can be lit；If certain is only IGBT is short-circuited fault, then the voltage at its two ends is substantially zeroed, and LED will not be lit, and i.e. can determine that its correspondence this One-level IGBT has occurred that short trouble.

Fig. 1 is the schematic diagram of semiconductor switch serial module structure.Tandem tap module is made up of n level, the most numbered 1, 2、3、…、n.Every one-level is an elementary cell, as shown in dashed rectangle.Elementary cell by triggering circuit Vi, quasiconductor is opened Closing Qi and static voltage sharing Ri composition, wherein i is the numbering of i-stage unit.The equivalent internal resistance of semiconductor switch is by its work Make the ratio decision of voltage and leakage current, be generally tens of to up to a hundred M Ω.For realizing the partial pressure value at IGBT two ends at different levels Of substantially equal, static voltage sharing is typically than the little an order of magnitude of equivalent internal resistance, and the partial pressure value at such IGBT two ends is main Determined by static voltage sharing.The static voltage sharing of unit at different levels selects identical resistance, it is ensured that the partial pressure value of IGBT at different levels Essentially identical, prevent that unbalanced-voltage-division is even causes some IGBT over-voltage breakdown.

Fig. 2 be the present invention to the improvement circuit theory diagrams of certain primary unit in tandem tap module, in tandem tap module The improved method of other each unit is identical with this.

The fault if switch Q is not short-circuited, is gradually increased certain voltage at its two ends and observes.If switch Q The voltage at two ends is U_Q, resistance R_bThe voltage at two ends is U_D, LED conducting luminous time forward direction tube voltage drop be U_F, work as U_D ＜ U_FTime, light emitting diode does not works, and LED can be regarded as open-circuit condition, now meets formula (1).

$U_D=\frac{R_b}{R_a+R_b}{U}_Q\mathrm{...}\left(1\right)$

Along with U_QIncrease, U_DAlso increasing, working as U_D≥U_FAfter, light emitting diode is lit, and the voltage at two ends is clamped at U_FAnd it is held essentially constant.

If the switch of a certain unit or certain what unit there occurs short trouble in serial semiconductor switch, break down Switch equivalent resistance be essentially 0, the voltage at two ends is essentially 0, will not be with the voltage at serial semiconductor switch module two ends Change.Therefore, the LED of corresponding unit will not be lit.

Therefore, it is judged that the method for the switch of the fault that is short-circuited is: apply relatively low at serial semiconductor switch module two ends Voltage, it is ensured that now the LED of normal cell can be lit.Observe all of LED, if some LED is not lit, then Can determine that the semiconductor switch that these unit are corresponding there occurs short trouble.

The choosing method of every grade of unit component parameter is as follows: apply test at n level serial semiconductor switch module two ends Voltage U_M, and U_MNot can exceed that the maximum of single only switch is pressure, to prevent from damaging switch.If certain one-level switch is normal, then its The voltage got is at least U_M/n.When meeting formula (2), i.e. resistance R_bThe voltage at two ends is more than or equal to LED forward direction tube voltage drop U_F Time, the LED of normal condition unit just can be lit.

$\frac{R_b}{R_a+R_b}\·\frac{U_M}{n}\≥U_F\mathrm{...}\left(2\right)$

If it is I that eyes are able to observe that LED luminescence needs to flow through the minimum current of LED_F, then formula (3) it must is fulfilled for.

$\frac{\frac{U_M}{n}-U_F}{R_a}-\frac{U_F}{R_b}\≥I_F\mathrm{...}\left(3\right)$

Due to needs R_b＜ ＜ R_a, engineering can be chosen by formula (4).

R_b≤0.1R_a……………………………………………(4)

When meeting formula (2), (3), (4) simultaneously, the LED of normal cell can be lit, and the LED of IGBT short-circuit unit will not It is lit.

Illustrate: according to the characteristic of semiconductor switch, if selecting the resistance of static voltage sharing to be about 2M in She Ji Ω, due to R_b＜ ＜ R_aThen it is believed that R_a=2M Ω；The electricity that if serial semiconductor switch module has n=8 level, two ends apply Pressure U_M=1000V；The forward voltage drop U of LEDs ON_F=1.6V, can be observed luminescence minimum current I_F=40 μ A；Then 71k Ω≤R can be calculated according to formula (2), (3), (4)_b≤200kΩ.During design circuit, can consider each Item parameter, is allowed to meet above-mentioned condition.

The invention is not limited in aforesaid detailed description of the invention.The present invention expands to any disclose in this manual New feature or any new combination, and the arbitrary new method that discloses or the step of process or any new combination.

Claims (4)

1. an indicating circuit for serial semiconductor switch short trouble, the IGBT switch being integrated including some grades of series connection, institute State every one-level IGBT switch ends static voltage sharing in parallel, it is characterised in that the static state on described every one-level IGBT switch Equalizing resistance includes that an equalizing resistance connected and auxiliary equalizing resistance, one in parallel of the two ends of described auxiliary equalizing resistance are sent out Optical diode；

The voltage at described auxiliary equalizing resistance two ends is not less than the forward direction tube voltage drop of Light-Emitting Diode, and the resistance of equalizing resistance is more than The resistance of auxiliary equalizing resistance, the electric current on described Light-Emitting Diode is not more than the electric current of equalizing resistance and auxiliary equalizing resistance Difference.

The indicating circuit of a kind of serial semiconductor switch short trouble the most according to claim 1, it is characterised in that described The voltage value of every one-level IGBT switch ends is equal.

The indicating circuit of a kind of serial semiconductor switch short trouble the most according to claim 2, it is characterised in that each The resistance of the equivalent internal resistance of level IGBT switch is more than static voltage sharing resistance value an order of magnitude.

The indicating circuit of a kind of serial semiconductor switch short trouble the most according to claim 3, it is characterised in that described The resistance of equalizing resistance is much larger than the resistance of auxiliary equalizing resistance, and the resistance of described auxiliary equalizing resistance is not more than 0.1 times and all presses The resistance of resistance.