CN2217857Y

CN2217857Y - Device for envenly distributing current while multiple parallel-connected semiconductor devices are running

Info

Publication number: CN2217857Y
Application number: CN95203142U
Authority: CN
Inventors: 王钟秀
Original assignee: Individual
Current assignee: Individual
Priority date: 1995-02-24
Filing date: 1995-02-24
Publication date: 1996-01-17
Anticipated expiration: 2005-02-24

Abstract

The utility model relates to a device for evenly distributing current while multiple parallel-connected semiconductor devices are running, which is connected with a curve resistance or a constant voltage nonloss resistance between the two input ends of the evenly distributing current mutual inductor, avoiding the overvoltage generated at the two sides of the mutual inductor and effectively achieving the purpose of evenly distributing current. The utility model has the advantages of simple circuit and convenient operation, and can be used for the evenly distributing current of two or more components in parallel connection.

Description

A kind of current equalizer of a plurality of semiconductor device parallel runnings

The utility model belongs to the circuit arrangement of power supply or distribution, the current equalizer when being specifically related to the semiconductor device parallel running.

In the high-power device that semiconductor device is formed, usually need be with a plurality of device parallel runnings when electric current is big, and wish that electric current can be allocated in each device in parallel more equably.Flow equalize technology commonly used has two kinds of inductance current-sharing and instrument transformer current-sharings.The inductance flow equalize technology adopts inductance and each device to be connected into a branch road, and then with each branch road parallel connection.This technology has two major defects: the one, and the current-sharing effect is undesirable; The 2nd, inductance too conference influences performances such as the change of current, starting, and is particularly unfavorable when frequency is higher.The instrument transformer current-sharing schematic circuit of a plurality of semiconductor device parallel runnings, be between every adjacent two device inputs in parallel, to connect an equal current transformer, 1,2,3,4,5,6 six semiconductor device parallel running circuit is for example arranged, then respectively 1 and 2,2 and 3,3 and 4,4 and 5 and 5 and 6 each connect an equal current transformer between to the device input.With two devices in parallel is example, and its connecting mode as shown in Figure 1.Its current-sharing effect is fine, but causes overvoltage easily, and is especially even more serious when the switching characteristic of each device in parallel is inconsistent, thereby is difficult to practicality.

The utility model is the shortcoming that will overcome prior art, provides that a kind of loss is little, current-sharing is effective, the current equalizer in the time of can not causing superpotential semiconductor device parallel running.

The technical scheme of taking for achieving the above object: the difference of the utility model and existing instrument transformer current equalizer shown in Figure 1 is that each instrument transformer is imported and all connects a nonlinear resistance or " constant voltage loss-less resistor " between two ends.

The drawing explanation:

Fig. 1 is the basic circuit diagram of existing instrument transformer current equalizer;

Fig. 2 imports at instrument transformer for the utility model employing and connects nonlinear resistance current equalizer schematic diagram between two ends.Wherein Fig. 2 (a) is a basic circuit diagram; Fig. 2 (b) is the nonlinear resistance property curve;

Fig. 3 imports the current-sharing schematic diagram that connects " constant voltage loss-less resistor " between two ends for the utility model adopts at instrument transformer.Wherein Fig. 3 (a) is the current-sharing basic circuit diagram; Fig. 3 (b) is the circuit characteristic curve of " constant voltage loss-less resistor " 5; Fig. 3 (c) is the equivalent circuit diagram of " constant voltage loss-less resistor " 5.

For further understanding the characteristics of the technical program, describe the problem that prior art circuits exists in detail with reference to Fig. 1 earlier.1,2 for needing two semiconductor device in parallel of equal flow distribution among Fig. 1; 3 is equal current transformer.This instrument transformer by about two half coils be connected into 1: 1 current transformer of an autocoupling type, general left and right sides two halves coil turn equates (promptly 1: 1), must equate according to two half coil electric currents about the current transformer principle, so device 1,2 is able to current-sharing.But open (or turn-off) when having one in 1,2 two device and another when not opening (or turn-offing as yet) as yet, then be equivalent to only side open circuit of current transformer, this moment, too high voltages will appear, may damage device.This is the problem that should solve in the prior art.

Two embodiment of scheme are described with reference to the accompanying drawings:

Example 1:

Shown in Fig. 2 (a), between input two ends of instrument transformer 3, connect a nonlinear resistance 4, the current-voltage characteristic of this resistance is shown in Fig. 2 (b).Its voltage drop when little electric current, presents high electrical resistance, when big electric current, presents, so still can be tending towards a little limiting value V when electric current is very big than low resistance _Kp(as 4～5V).Because limit pressure drop is little, thus when devices switch characteristic in parallel is inconsistent also unlikely damage device.Again because high resistance is arranged during little electric current, when making instrument transformer two input electric currents (i.e. the electric current of two devices in parallel) that less difference be arranged, part difference currents will flow through nonlinear resistance 4, can produce tangible instrument transformer terminal voltage, this terminal voltage will make two device current be tending towards even, be big will the reducing of electric current, what electric current was little will increase, thereby reaches the effect of current-sharing.

Example 2:

Shown in Fig. 3 (a), increase by one at each instrument transformer 3 and pay the limit, receive respectively on " the constant voltage loss-less resistor " 5 on this pair limit, and so-called " constant voltage loss-less resistor " is actually the equivalent resistance of circuit shown in Fig. 3 (c).Mainly contain a constant voltage source E (the constant voltage value is E) in this circuit.Instrument transformer is paid the limit can constantly import electric energy constant voltage source so far.Therefore for instrument transformer, this circuit is rendered as a constant voltage resistance that absorbs electric energy.But this electric energy does not lose, and it can discharge in other electricity consumption loops again and (for example use the input DC power of inverter), so claim loss-less resistor.Its electric current one voltage response is shown in Fig. 3 (b).It is more even more ideal than Fig. 2 (b), i.e. vertical rising in limiting voltage E place characteristic line; And electric current is almost nil when voltage is lower than limiting voltage E, and promptly resistance is almost infinity, the current-sharing better effects if, and its current-sharing principle is to similar described in the example 1.

Advantage of the present utility model:

1. can limit the voltage of transformer, avoid occurring too high voltages, simultaneously again can be effectively Reach the current-sharing purpose;

2. simplely be convenient to practicality.

The utility model both had been applicable to two device current-sharings in parallel, also extended to more a plurality of devices in parallel and carried out current-sharing by a plurality of instrument transformers.

Claims

1. the current equalizer during an a plurality of semiconductor device parallel running is connecing an equal current transformer between every adjacent two device inputs in parallel, it is characterized in that importing at each instrument transformer all connecing a nonlinear resistance [4] between two ends.

2. the current equalizer during an a plurality of semiconductor device parallel running, between every adjacent two device inputs in parallel, connect an equal current transformer, it is characterized in that importing and all connect a constant voltage loss-less resistor [5] between two ends at each instrument transformer, it is the equivalent resistance of a circuit, this circuit mainly contains constant voltage source E, pays the limit from instrument transformer electric energy is imported this constant voltage source.