The power supply of average current type current-equalizing circuit and composition thereof and power-supply system
[technical field]
The present invention relates to the power supply and the power-supply system of a kind of flow equalizing circuit and composition thereof, the power supply and the power-supply system of particularly a kind of average current type current-equalizing circuit and composition thereof.
[background technology]
The average current type current current equalizing method is a kind of method commonly used in the flow equalizing circuit, have circuit simple, use the advantage that device is few, cost is low, the current-sharing precision is more high.Current-sharing in the general flow equalizing circuit is regulated operational amplifier and is all only adopted single power supply, promptly has only positive supply VCC, and another power end is ground connection then.So operational amplifier can only be exported positive level, can not export negative level, like this in modular system in parallel, output current less than the module of average current only to export a positive level, heighten its output, the module that is higher than average current is not then regulated, and just can only unidirectionally regulate.
Figure 1 shows that the schematic diagram of at present commonly used a kind of current-sharing power supply system, the output of each power module is by the parallel connection of output bus, and is connected in parallel by current equalizing bus bar, to control the current-sharing of each module.Electric current is the average current of whole modules in the system on the current equalizing bus bar, flow equalizing circuit in each module is all by relatively the electric current of this module and the size of average current are regulated, when the electric current of this module during less than the average current of system, heighten the output voltage of this module, thereby increase the output current of this module.But the module that is higher than average current for output current is not regulated, just distribution naturally by electric current reach current-sharing purpose---total load current is certain, when the blocks current that output current is lower than average current is enhanced, the output current that output current is higher than the module of average current has just reduced naturally, need not flow equalizing circuit and regulates.
But all can there be a very general problem in such regulative mode---be the equal flow problem of underloading.
Owing to reason such as device is imperfect, the unidirectional regulative mode of so only heightening the low module of electric current is very little at load current, can't differentiate the relation between this module output current and the system's average current when being underloading, can't realize current-sharing thereby cause---because the non-ideal characteristic of device, operational amplifier in the sample circuit can not be exported desirable ground level, but a minimum level is arranged, such as 0.7V, therefore in certain loading range, the output signal k*Io of sampling operational amplifier does not change with the variation of load.Such as module 1 output 1A, should obtain the 0.3V signal; And module 2 output 0A should obtain the 0V signal.Because the existence of minimum level 0.7V, so two modules are all exported 0.7V, the flow equalizing circuit of back just thinks that two module output currents equate so, does not regulate, and therefore just can't realize current-sharing.
Simultaneously, because the discreteness of device, each blocks current sampled signal is also inconsistent, in the scope that can't regulate, little by little little deviation all can cause the output of flow equalizing circuit saturated, thereby raise the wherein output voltage of certain module,, then can influence the normal operation of system to a great extent if the regulating power of flow equalizing circuit is stronger.With top example is example, module 1 output 1A, and k*Io obtains minimum level 0.6V, module 2 output 0A, k*Io obtains minimum level 0.7V.The flow equalizing circuit of back thinks that the electric current of current ratio module 1 of module 2 is big so, therefore remove to heighten the output voltage of module 1, and signal k*Io still remains unchanged, so the circuit output of adjustment module 1 always, up to the current-sharing of module 1 regulate operational amplifier saturated till.So just brought second problem of unidirectional adjusting, promptly certain module can be heightened by other module improperly, influences the normal operation of system.
Industry is for these two problems, and the general regulating power that reduces flow equalizing circuit that adopts makes when underloading heightening of certain module output voltage to be arranged in the scope that can bear, but just can't accomplish precise current-equalizing like this.Perhaps go to repair this defective, but the cost of whole system will raise like this by designing some other complicated peripheral circuit.
In the existing flow equalizing circuit, the problem that also has current-limiting points drift after the module parallel connection: if adopt ground wire resistance sampling electric current, so after module is together in parallel, reason owing to the inside modules grounding wire impedance, can cause the drift of ground wire current potential, thereby the very big current sampling signal that influences changes current-limiting points, can't accomplish precise current-equalizing.As shown in Figure 2, because inevitably there is asymmetry in two in parallel modules, so have pressure reduction between a1 and the a2 at 2.If the negative pole Share-of current equalizing bus bar links to each other between separately the ground wire, this pressure reduction is dividing potential drop and be added in a1, a2 between the ground separately directly, that is to say that there are pressure reduction in a1, a2 between ground separately, thereby influenced current sampling signal IO1 and IO2 separately.Because the own signal of IO1 and IO2 is just very little, so this influence is very big, current-limiting points may be reduced to original 50% in addition below, system is therefore basic just can't operate as normal.
[summary of the invention]
But the object of the present invention is to provide the power supply and the power-supply system of the average current type current-equalizing circuit and the composition thereof of a kind of bidirectional modulation, no current-limiting points drifting problem, can realize full-load range precise current-equalizing.
The technical solution adopted for the present invention to solve the technical problems is: average current type current-equalizing circuit, comprise current sample amplifying circuit, current-sharing regulating circuit and amplitude limiter circuit, described current sample amplifying circuit comprises one first operational amplifier, and described first operational amplifier adopts positive and negative dual power supply.
Described current-sharing regulating circuit comprises second operational amplifier that adopts positive and negative dual power supply.
The positive input coupling of the positive pole of current equalizing bus bar and second operational amplifier; The negative pole of current equalizing bus bar is by the 8th grounding through resistance.
Described current-sharing regulating circuit comprises the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance and second operational amplifier;
After linking to each other with an end of the 5th resistance, the 4th resistance links to each other with the output of current sample amplifying circuit, the other end of the 4th resistance links to each other with the reverse input end of second operational amplifier, and the other end of the 5th resistance links to each other with the positive input of second operational amplifier; The positive input of one termination, second operational amplifier of the 6th resistance, other end ground connection; The 7th resistance cross-over connection is in the reverse input end and the output of second operational amplifier; The output of second operational amplifier links to each other with the input of amplitude limiter circuit; The positive pole of current equalizing bus bar links to each other with the positive input of second operational amplifier, and its negative pole is by the 8th grounding through resistance.
Also comprise second electric capacity; Described second electric capacity and reverse input end and the output of the 7th resistance cross-over connection in parallel in second operational amplifier.
Also comprise second electric capacity; Described second electric capacity is connected cross-over connection in the reverse input end and the output of second operational amplifier with the 7th resistance.
In the foregoing circuit, the resistance of the 4th resistance and the 5th resistance equates; The resistance of the 6th resistance equates with the resistance of the 7th resistance.
Described current-sharing regulating circuit comprises the 4th resistance, the 5th resistance, the 6th resistance, the 7th resistance, the 8th resistance, the 11 resistance and second operational amplifier;
Link to each other with the output of current sample amplifying circuit after the 4th resistance links to each other with an end of the 5th resistance, the other end of the 4th resistance links to each other with the reverse input end of second operational amplifier, and the other end of the 5th resistance links to each other with an end of the 11 resistance; The other end of the 11 resistance links to each other with the positive input of second operational amplifier; The positive input of one termination, second operational amplifier of the 6th resistance, other end ground connection; The 7th resistance cross-over connection is in the reverse input end and the output of second operational amplifier; The output of second operational amplifier links to each other with the input of amplitude limiter circuit; The positive pole of current equalizing bus bar links to each other with the tie point of the 5th resistance and the 11 resistance, and its negative pole is by the 8th grounding through resistance.
In the foregoing circuit, the resistance of the 4th resistance, the 5th resistance and the 11 resistance equates; The resistance of the 6th resistance is the twice of the 7th resistance.
Described current sample amplifying circuit comprises first resistance, second resistance and first operational amplifier; One this module output signal of termination IO of first resistance, the reverse input end of another termination first operational amplifier; The reverse input end and the output of the second resistance cross-over connection and first operational amplifier; The positive input ground connection of first operational amplifier, its output links to each other with the input of current-sharing regulating circuit.
The present invention also provides a kind of power module of average current type current-equalizing circuit, and the module earth point links to each other with the current equalizing bus bar negative pole;
Link to each other by the 8th resistance between the earth point of described current-sharing module and the negative pole of current equalizing bus bar.
The present invention also provides a kind of power-supply system of average current type current-equalizing circuit, comprises at least two power modules, and each module earth terminal is connected as the negative pole of current-sharing output bus; In described each power module, the resistance of connecting respectively between the earth point of each module.
The present invention gives the adjusting operational amplifier power supply of flow equalizing circuit by introducing negative and positive dual power, make its output just can bear, all modules all can be regulated, solved two problems of the prior art well---because the introducing of negative supply, the output of ground level just can be very accurate, therefore just well current-sharing when underloading a module can not occur and too be raised the situation of output voltage by other module, has realized full-load range precise current-equalizing.Circuit is simple and reliable, need not increase the performance that cost has promptly improved system greatly.The present invention is by in flow equalizing circuit, the negative pole of current equalizing bus bar is passed through a grounding through resistance, solved the problem of current-limiting points drift---and since this resistance in Fig. 2 a1, a2 to the impedance of ground wire separately, so because the asymmetric pressure drop that causes of module substantially all is added on this resistance, can not influence a1, a2 current potential over the ground, just can not influence current sampling signal, as shown in Figure 3 yet.
[description of drawings]
Fig. 1 is the structural representation of existing a kind of current-sharing power supply system.
Fig. 2 is the electrical block diagram that causes the current-limiting points drifting problem in the prior art.
Fig. 3 is the electrical block diagram that the present invention solves circuit problem shown in Figure 2.
Fig. 4 is the electrical block diagram of average current type current-equalizing circuit of the present invention.
Fig. 5 is the structured flowchart of average current type current current-sharing power supply module of the present invention.
Fig. 6 is the structured flowchart of average current type current current-sharing power supply of the present invention system.
Fig. 7 is the electrical block diagram of average current type current-equalizing circuit in the second embodiment of the invention.
Fig. 8 is the electrical block diagram of current-sharing regulating circuit in the third embodiment of the invention.
Fig. 9 is the electrical block diagram of current-sharing regulating circuit in the four embodiment of the invention.
[embodiment]
With specific embodiment the present invention is done to set forth further with reference to the accompanying drawings below.Operational amplifier among the following embodiment all adopts positive and negative dual power supply.
Embodiment one:
As shown in Figure 4, a kind of average current type current-equalizing circuit comprises the current sample amplifying circuit 1, current-sharing regulating circuit 2 and the amplitude limiter circuit 3 that link to each other in turn.
Described current sample amplifying circuit 1 adopts see-saw circuit to comprise first resistance R 1, second resistance R 2 and first operational amplifier A 1.First operational amplifier A 1 adopts the dual power supply of positive-negative power.One this module output signal of termination IO of first resistance R 1, the reverse input end of another termination first operational amplifier A 1, the reverse input end and the output of 2 cross-over connections of second resistance R and first operational amplifier A 1.The positive input ground connection of first operational amplifier A 1, its output links to each other with the input of current-sharing regulating circuit 2.
Current-sharing regulating circuit 2 comprises the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8 and second operational amplifier A 2.Second operational amplifier A 2 adopts the dual power supply of positive-negative power.After linking to each other with an end of the 5th resistance R 5, the 4th resistance R 4 links to each other with the output of current sample amplifying circuit 1, the other end of the 4th resistance R 4 links to each other with the reverse input end of second operational amplifier A 2, and the other end of the 5th resistance R 5 links to each other with the positive input of second operational amplifier A 2.The positive input of one termination, second operational amplifier A 2 of the 6th resistance R 6, other end ground connection.7 cross-over connections of the 7th resistance R are in the reverse input end and the output of second operational amplifier A 2.The output of second operational amplifier A 2 links to each other with the input of amplitude limiter circuit 3.The anodal Share+ of current equalizing bus bar links to each other with the positive input of second operational amplifier A 2, and its negative pole Share-is by the 8th resistance R 8 ground connection.Wherein, the resistance of the 4th resistance R 4 and the 5th resistance R 5 equates; The resistance of the 6th resistance R 6 equates with the resistance of the 7th resistance R 7.
Amplitude limiter circuit 3 comprises first capacitor C 1 and voltage stabilizing didoe D1; The positive pole of first capacitor C 1 link to each other with the negative electrode of voltage stabilizing didoe D1 back and the coupling of the output of current-sharing regulating circuit 2, simultaneously as the Voltage Feedback of the output of amplitude limiter circuit 3 and this power module relatively circuit b be coupled both other end ground connection.
To sum up, current sample amplifying circuit 1 obtains k*Io signal (k=R2/R1) by the current sampling signal amplifier of first operational amplifier A 1 and peripheral circuit composition link.Current-sharing regulating circuit 2 is by the voltage error amplifier of second operational amplifier A 2 and peripheral circuit composition link, compare the average current signal on this module output current and the current equalizing bus bar, obtain the error conditioning signal, remove to regulate the output voltage of this module by a resistance-capacitance network amplitude limiter circuit 3 again, each module reaches current-sharing in the system thereby make.The output signal Vs of current-sharing regulating circuit 2 satisfies relation:
Wherein, I
1~ I
nBe the current signal k*I of each module, m is the error amplification coefficient, m=R6/R4.The output that is amplifier is proportional to the average current of all modules and the difference of this blocks current.This output signal is connected to the Voltage loop benchmark of this module by some resistance-capacitance networks, thereby regulates the output voltage of this module.
Flow equalizing circuit of the present invention, owing to introduce the dual power supply of positive-negative power, amplifier output can just can be born like this, all modules all can be regulated, electric current is higher than the output voltage of turning down of average current, and electric current is lower than the output voltage of heightening of average current, has realized bidirectional modulation.For current sample amplifying circuit 1, the problem that bidirectional modulation has existed when having solved aforementioned average current mode flow equalizing circuit underloading.Because the introducing of negative supply, the output of ground level just can be very accurate, and be adjustable near this, so a module is too raised output voltage by other module situation can not appear in just well current-sharing naturally when underloading yet.For current-sharing regulating circuit 2, after the parallel connection,, this blocks current is higher than zero level, the output that so just can raise this module if less than system's average current, then needing to export one; And if this blocks current then needs to export one and is lower than zero level greater than system's average current, could effectively reduce the output of this module like this, carry out the precise current-equalizing of full-load range.Therefore, circuit of the present invention can be realized the FR precise current-equalizing of load, and circuit is simple and reliable, need not increase the performance that cost has promptly improved system greatly.
As shown in Figure 5, a kind of power module of average current type current-equalizing circuit comprises AC/DC module a, Voltage Feedback relatively circuit b, pwm circuit c and average current type current-equalizing circuit d.The input of AC/DC module a links to each other with external AC power supply, and its output links to each other with direct current output bus.The Voltage Feedback relatively input of circuit b links to each other with the output of AC/DC module a, and its control end links to each other with the output of flow equalizing circuit d, and its output links to each other with the input of pwm circuit c.The output of pwm circuit c links to each other with the control end of AC/DC module a.The sampling end of flow equalizing circuit d links to each other with the output of AC/DC module a, and its current-sharing end links to each other with current equalizing bus bar.Wherein, among the flow equalizing circuit d, the negative pole Share-of current equalizing bus bar is by the 8th resistance R 8 ground connection.
As shown in Figure 6, a kind of power-supply system of average current type current-equalizing circuit comprises at least two power modules, and the dc output end of each power module links to each other with direct current output bus, and the current-sharing end links to each other with current equalizing bus bar.In above-mentioned each power module, the negative pole Share-of current equalizing bus bar is by the 8th resistance R 8 ground connection.
The present invention passes through the 8th resistance R 8 ground connection by the negative pole Share-with current equalizing bus bar in each module, has solved because the current-limiting points drifting problem that asymmetry caused of each module.As shown in Figure 3, the 8th resistance R 8 is one tens ohm a resistance, because its resistance is much larger than a1, a2 to the impedance of ground wire separately, so because the asymmetric pressure drop that causes of module substantially all is added on these two resistance, can not influence a1, a2 current potential over the ground, just can not influence current sampling signal yet.So just solved the problem of the serious drift of current-limiting points after the module parallel connection.
Embodiment two:
As shown in Figure 7, a kind of average current type current-equalizing circuit comprises the current sample amplifying circuit 1, current-sharing regulating circuit 2 and the amplitude limiter circuit 3 that link to each other in turn.
Described current sample amplifying circuit 1 adopts differential amplifier circuit, comprises two first resistance (R1 and R1 '), two second resistance (R2 and R2 ') and first operational amplifier A 1.First operational amplifier A 1 adopts the dual power supply of positive-negative power.One this module of termination forward output signal V2 of first resistance R 1, the reverse input end of another termination first operational amplifier A 1.The reverse input end and the output of 2 cross-over connections of second resistance R and first operational amplifier A 1.First resistance R 1 ' the reverse output signal V1 of this module of termination, the positive input of another termination first operational amplifier A 1.Second resistance R, 2 ' one ends link to each other other end ground connection with the positive input of first operational amplifier A 1.The output of first operational amplifier A 1 links to each other with the input of current-sharing regulating circuit 2.
Current-sharing regulating circuit 2 comprises the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8, second capacitor C 2 and second operational amplifier A 2.After linking to each other with an end of the 5th resistance R 5, the 4th resistance R 4 links to each other with the output of current sample amplifying circuit 1, the other end of the 4th resistance R 4 links to each other with the reverse input end of second operational amplifier A 2, and the other end of the 5th resistance R 5 links to each other with the positive input of second operational amplifier A 2.The positive input of one termination, second operational amplifier A 2 of the 6th resistance R 6, other end ground connection.The back cross-over connections in parallel with second capacitor C 2 of the 7th resistance R 7 are in the reverse input end and the output of second operational amplifier A 2.The output of second operational amplifier A 2 links to each other with the input of amplitude limiter circuit 3.The anodal Share+ of current equalizing bus bar links to each other with the positive input of second operational amplifier A 2, and its negative pole Share-is by the 8th resistance R 8 ground connection.Wherein, the resistance of the 4th resistance R 4 and the 5th resistance R 5 equates; The resistance of the 6th resistance R 6 equates with the 7th resistance R 7.Wherein, second operational amplifier A 2 adopts positive and negative dual power supply.
Amplitude limiter circuit 3 is to be made of voltage stabilizing didoe D1, and the output coupling of its negative electrode and current-sharing regulating circuit 2 is compared circuit b coupling, plus earth as the output of amplitude limiter circuit 3 and the Voltage Feedback of this power module simultaneously.
Identical among the average current type current current-sharing power supply module in the present embodiment and the structure of power-supply system and the embodiment one.
Embodiment three:
As shown in Figure 8, the current sample amplifying circuit 1 in the average current type current-equalizing circuit in the present embodiment is identical with circuit structure among the embodiment one, and amplitude limiter circuit 3 is identical with circuit structure among the embodiment two.Identical among the structure of average current type current current-sharing power supply module and power-supply system and the embodiment one.
Current-sharing regulating circuit 2 comprises the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R 8, second capacitor C 2 and second operational amplifier A 2.After linking to each other with an end of the 5th resistance R 5, the 4th resistance R 4 links to each other with the output of current sample amplifying circuit 1, the other end of the 4th resistance R 4 links to each other with the reverse input end of second operational amplifier A 2, and the other end of the 5th resistance R 5 links to each other with the positive input of second operational amplifier A 2.The positive input of one termination, second operational amplifier A 2 of the 6th resistance R 6, other end ground connection.The 7th resistance R 7 is connected the back cross-over connection in the reverse input end and the output of second operational amplifier A 2 with second capacitor C 2.The output of second operational amplifier A 2 links to each other with the input of amplitude limiter circuit 3.The anodal Share+ of current equalizing bus bar links to each other with the positive input of second operational amplifier A 2, and its negative pole Share-is by the 8th resistance R 8 ground connection.Wherein, the resistance of the 4th resistance R 4 and the 5th resistance R 5 equates; The resistance of the 6th resistance R 6 is identical with the resistance of the 7th resistance R 7.Wherein, second operational amplifier A 2 adopts positive and negative dual power supply.
Embodiment four:
As shown in Figure 9, the current sample amplifying circuit 1 in the average current type current-equalizing circuit in the present embodiment and amplitude limiter circuit 3 are identical with circuit structure among the embodiment one.The structure of average current type current current-sharing power supply module and power-supply system with
Identical among the embodiment one.
Current-sharing regulating circuit 2 comprises the 4th resistance R 4, the 5th resistance R 5, the 6th resistance R 6, the 7th resistance R 7, the 8th resistance R the 8, the 11 resistance R 11 and second operational amplifier A 2.Wherein, second operational amplifier A 2 adopts positive and negative dual power supply.After linking to each other with an end of the 5th resistance R 5, the 4th resistance R 4 links to each other with the output of current sample amplifying circuit 1, the other end of the 4th resistance R 4 links to each other with the reverse input end of second operational amplifier A 2, and the other end of the 5th resistance R 5 links to each other with an end of the 11 resistance R 11.The other end of the 11 resistance R 11 links to each other with the positive input of second operational amplifier A 2.The positive input of one termination, second operational amplifier A 2 of the 6th resistance R 6, other end ground connection.7 cross-over connections of the 7th resistance R are in the reverse input end and the output of second operational amplifier A 2.The output of second operational amplifier A 2 links to each other with the input of amplitude limiter circuit 3.The anodal Share+ of current equalizing bus bar links to each other with the tie point of the 5th resistance R 5 and the 11 resistance R 11, and its negative pole Share-is by the 8th resistance R 8 ground connection.
Wherein, the resistance of the 4th resistance R 4, the 5th resistance R 5 and the 11 resistance R 11 equates.The resistance of the 6th resistance R 6 is the twice of the 7th resistance R 7.