CN203761123U - UPS parallel operation current sampling and converting control system - Google Patents

Abstract

The utility model brings forward an UPS parallel operation current sampling and converting control system. The system comprises an output current sampling circuit, a parallel operation current signal control circuit, a converting circuit and a DSP control circuit. The input end of the converting circuit is connected with the output current sampling circuit and the parallel operation current signal control circuit, and the output end of the converting circuit is connected with the DSP control circuit, so that positive and negative output current sampling signals (I_+, I_-) and positive and negative parallel operation current signals (IBUS_I+, IBUS_I-) are converted into current sampling signals (IOP_POB) and current circulation control signals (IOP_ERR) for parallel operation and are then sent to the DSP control circuit. According to the scheme, a winding is shared by current sampling devices to complete stand-alone and parallel operation current sampling, so the system can be used for output current sampling in a parallel operation mode and a stand-alone mode. In the stand-alone mode, circuits of a parallel operation portion will not work and circuit sampling of the stand-alone mode will not be affected. The system has circuit structures simple in control mode, has less peripheral circuits and is worth of being popularized.

Description

A kind of UPS parallel operation current sample switching control system

Technical field

The utility model patent relates to power electronic equipment technical field, relates in particular to a kind of parallel operation current sample switching control system for UPS parallel operation.

Background technology

UPS (Uninterruptible Power System) uninterrupted power supply is as a kind of power equipment that improves power supply reliability and power supply quality, the high-quality power supply of voltage stabilizing, frequency stabilization can be provided to load all the time, suppress the impact of the power supply interference load such as spike, surge, noise and the bucking voltage depression of electrical network simultaneously, for UPS user, the parallel connection of many UPS modules powers to the load, can improve greatly stability and the reliability of power supply, also can form more powerful electric power system, dilatation facilitates, is easy to maintenance etc.

UPS (or inverter) is because output is sinusoidal ac, parallel running need to be considered the factor of amplitude, frequency and phase place, want well to carry out parallel output and to reduce circulation, its controlling of sampling mode just seems and is important, and parallel operation current sample control mode is wherein with regard to particular importance.Some parallel operation current sample need to arrange two groups of sampling resistors in Current Transformer Secondary side, circulation control signal is controlled separately, and then to parallel operation plate, signal is further processed, increase complexity and the debugging difficulty of circuit, also increase the out of order probability of circuit.

Utility model content

The utility model is intended to propose a kind of brand-new solution, is applicable to current sampling device, method of work and the switching control system of parallel operation UPS (or inverter).

The technical scheme that the utility model adopts comprises:

A kind of UPS parallel operation current sample switching control system, be connected with one or many UPS, this system comprises output current sample circuit, parallel operation current signal control circuit, change-over circuit and DSP control circuit, wherein output current sample circuit comprises current transformer, once the surveying and export that L line is connected and its secondary side is connected with the first input end of change-over circuit of described current transformer, described parallel operation current signal control circuit comprises relay and control relay circuit, the signal output part of described parallel operation current signal control circuit is connected with the second input of change-over circuit, the output of described change-over circuit is connected with DSP control circuit, so that output current sample circuit is just being exported, negative output current sampled signal (I_+, I_-) and parallel operation current signal control circuit just bring, negative parallel operation current signal (IBUS_I+, IBUS_I-) convert current sampling signal (IOP_POB) and parallel operation electric current circulation control signal (IOP_ERR) to and send into DSP control circuit.

One as above technical scheme is improved, described change-over circuit comprises the first anti-phase ratio amplifying circuit being connected with positive parallel operation current signal (IBUS_I+) input with positive output current sampling signal (I_+) input, described the first anti-phase ratio amplifying circuit rear end is connected with the first bleeder circuit and the first voltage follower in turn, described change-over circuit also comprises the second anti-phase ratio amplifying circuit being connected with negative parallel operation current signal (IBUS_I-) input with negative output current sampled signal (I_-) input, described the second anti-phase ratio amplifying circuit rear end is connected with the 3rd anti-phase ratio amplifying circuit in turn, the second bleeder circuit and second voltage follower, wherein said the 3rd anti-phase ratio amplifying circuit front end is also connected with negative parallel operation current signal (IBUS_I-) input with negative output current sampled signal (I_-) input.

One as above technical scheme is improved, the voltage signal of described current sampling signal (IOP_POB) for changing centered by 1.5VDC, electric current circulation control signal (IOP_ERR) dead level for 1.5VDC in the time that UPS unit uses for described parallel operation, in the time that UPS parallel operation is used, it is the voltage signal changing centered by 1.5VDC

One as above technical scheme is improved, and described first, second, and third anti-phase ratio amplifying circuit all adopts operational amplifier to form.

Improve as the one of above technical scheme, described change-over circuit also comprises high-frequency filter circuit and common mode, differential mode filter circuit.

One as above technical scheme is improved, and described bleeder circuit is to draw voltage branch circuit on 3.0VDC.

Therefore the utility model institute proposition system has adopted a kind of brand-new UPS parallel operation current sample conversion and control mode, it shares a winding, can complete unit output current sample conversion and the conversion of parallel operation current sample simultaneously.System of the present utility model comprises the output current sample circuit of current transformer and sampling resistor composition, the parallel operation current signal control circuit of relay and control relay circuit composition, and the change-over circuit being formed by clamp diode, amplifier, filter inductance and corresponding RC filter circuit, high-frequency filter circuit, common mode, differential mode filter circuit, voltage follow, scale operation circuit etc.Wherein, described current transformer and sampling resistor are sampled and current signal are converted to voltage signal the output current of UPS; described relay is controlled the input of parallel operation current signal; described clamp diode be by the voltage clamping of diode one end to the opposite side of diode for the protection of circuit below not by over-voltage breakdown; described part amplifier and peripheral circuit thereof form anti-phase ratio circuit; a part of amplifier forms voltage follower in addition, and described filter circuit is mainly by inductance, electric capacity, resistance combination of two or make separately for reaching filter effect.

The beneficial effects of the utility model are:

Current sampling device of the present utility model shares a winding, shares a sample circuit and completes unit and parallel operation current sample, both can, for parallel operation pattern, also can sample for the output current of single cpu mode.Under single cpu mode, the circuit of parallel operation part can not be worked, and can not affect the circuit sampling of single cpu mode, and circuit structure control mode is simple, and peripheral circuit is less.In addition, the utility model utilizes amplifier and a reverse scale operation circuit of peripheral capacitance resistance combination, independently goes out a circulation control signal, and circuit structure is simple, sampling high conformity.

Brief description of the drawings

Clearer for technical problem, technical scheme and beneficial effect that the utility model is solved, below in conjunction with drawings and Examples, the utility model is further elaborated.Should be appreciated that specific embodiment described herein is only applicable to explain the utility model, and be not used in restriction the utility model.In the appended accompanying drawing of the utility model:

Fig. 1 is the utility model operation principle block diagram;

Fig. 2 is output current sample circuit schematic diagram of the present utility model;

Fig. 3 is parallel operation current signal control circuit schematic diagram of the present utility model;

Fig. 4 is change-over circuit schematic diagram of the present utility model.

Embodiment

The utility model provides a kind of UPS parallel operation current sample switching control system, and as shown in Figure 1, it comprises output current sample circuit, parallel operation current signal control circuit, change-over circuit and DSP control circuit.Output current sample circuit comprises Current Transmit 1 and sampling resistor R1, parallel operation current signal control circuit comprises relay R Y1 and control relay circuit, wherein the primary side of Current Transmit 1 is connected on output L line, secondary side is connected on the input of change-over circuit, parallel operation current signal is also linked in change-over circuit by relay R Y1, and change-over circuit produces output current sampled signal and parallel operation uses electric current circulation control signal in DSP control circuit.

As shown in Figure 2, in output current sample circuit, output current is in output current sampled signal through isolation of Current Transmit 1 secondary side output, current signal is become voltage signal by resistance R 1, and amplitude that can regulation output voltage, C2, C3 are used for filtering common mode and disturb, and C1 is used for filtering differential mode interference.

As shown in Figure 3; parallel operation current signal control circuit comprises relay R Y1 and control relay circuit; wherein; H_BUS_AB signal is divided into a suitable voltage by resistance R 23, R24 and drives triode Q1; carry out turning on and off of control relay RY1 with this; D4 is for the coil inductance afterflow to relay R Y1; the induced voltage that when protection Q1 is not turned off, relay R Y1 coil produces punctures, the common mode disturbances on L3, L4, C12, C13 filtering input signal ISS_BUS_I+, ISS_BUS_I-.When unit uses, H_BUS_AB signal goes out low level always, and relay R Y1 is failure to actuate, and when parallel operation, H_BUS_AB signal goes out high level, relay 3,4 pin and 5,6 pin adhesives, and parallel operation current signal IBUS_I+ and IBUS_I-are sent in change-over circuit.

As shown in Figure 3, according to change-over circuit of the present utility model, for convert current sampling signal and the parallel operation electric current circulation control signal of sending into DSP control circuit to by the output current sampled signal of output current sample circuit output with through the parallel operation current signal of bringing of relay R Y1.In the time that UPS unit uses, control relay R Y1 open circuit, now on the anti-phase ratio amplification of positive output current signal I_+ process amplifier U1A (the first anti-phase ratio amplifying circuit), 3.0VDC, draw voltage dividing potential drop (the first bleeder circuit) and U1B voltage follow (the first voltage follower) to improve its output characteristic IOP_POB voltage signal changing of output (current sampling signal) afterwards centered by 1.5VDC, because I_-amplifies through the anti-phase ratio of amplifier U1C (the second anti-phase ratio amplifying circuit), R6, R7, R9, the coupling of R10 resistance, the 8 pin output voltages of UIC are contrary with the symbol of I_-, equal and opposite in direction, so when resistance R 11, when R12 is made as identical value, the 13 pin input voltages of U1D are zero, therefore the anti-phase ratio through amplifier U1D (the 3rd anti-phase ratio amplifying circuit) is amplified, on 3.0VDC, draw after voltage dividing potential drop (the second bleeder circuit) and U2A voltage follow (second voltage follower) improve its output characteristic, DIOP_ERR is the dead level (parallel operation electric current circulation control signal) of a 1.5VDC.Control relay adhesive in the time that UPS parallel operation is used, now IBUS_I+ and IBUS_I-are non-vanishing, the circuit of U1A becomes the anti-phase summing circuit by I_+ and IBUS_I+ signal from anti-phase ratio amplifying circuit, on 3.0VDC, draw voltage dividing potential drop and U1B voltage follower circuit partial parameters not to change, IOP_POB still exports a voltage signal changing centered by 1.5VDC; Because I_-amplifies through the anti-phase ratio of amplifier U1C, the coupling of R6, R7, R9, R10 resistance, the 8 pin output voltages of UIC are contrary with the symbol of I_-, equal and opposite in direction, so in the time that R11, R12 are made as identical value, the voltage that the 13 pin input voltages of U1D only amplify through anti-phase ratio for IBUS_I-, pass through a series of processing (through the 3rd anti-phase ratio amplifying circuit, the second bleeder circuit and second voltage follower), now IOP_ERR is a voltage signal changing centered by 1.5VDC again.

Can find out from above-mentioned scheme, output current is sent in change-over circuit after current transformer isolation sampling, can complete output electric current measure and the detection of parallel operation circulation by change-over circuit simultaneously, control relay adhesive in the time carrying out parallel operation, parallel operation signal is sent in change-over circuit, controls in DSP through being sent to after change-over circuit.The isolation of whole process and forceful electric power, parallel operation signal only has and just can participate in control when relay adhesive, and system safety is reliable.

In concrete enforcement, for the sampling output current of safety and precise, R1 will adopt noninductive precision resistance, and will ensure that born maximum power is in specified power bracket, and the resistance of resistance is chosen to be generally and in the time of maximum current, made the voltage of output be no more than 3VDC.C2, C3 filter common mode capacitance is in the safe range of controlling leakage current and can bearing at human body, unsuitable excessive, generally adopts the safety electric capacity of 10NF, and C1 differential mode capacitor need to be selected sizeable metal film electric capacity according to EMC.

In concrete enforcement, for relay R Y1 can normally be worked, 1 pin (driving pin) voltage of locating of triode Q1 and the electric current flowing through all should be in suitable scopes, voltage should be not less than the base-emitter pressure drop (being generally 0.7V) of Q1 after by R23, R24 dividing potential drop, the electric current flowing through while driving the maximum current that bears of pin, triode multiplication factor and relay work according to triode, choose the maximum, minimum value of R23, R24 in certain scope, be generally the resistance of 2～10K.D5 chooses fast (recovering soon) diode, common mode disturbances in L3, L4, C12, C13 filtering small-signal, L3, L4 generally choose the inductance (as 56UH) of microhenry rank, and it is proper that C12, C13 generally choose nanofarad rank (as 10nF).

In concrete enforcement, in order to make IOP_POB, IOP_ERR can export one and can be controlled the signal of DSP identification and improve and control effect, following components and parts should be chosen especially, L1, L2 is generally the inductance (as 56UH) of microhenry rank, C5, C8, C11, generally choose hundreds of PF to 2NF left and right, choose according to the concrete debugging of debugging effect, C7, C10 is the High-frequency Interference of filter power supply 3VDC, be generally the electric capacity of UF rank, C4, C6, C9 is filter capacitor, generally smaller, be advisable with tens PF, R4 and R5 sum equal R13, R6 and R7 sum equal R9, R8, R9, R11, R12, R13 equates, R15, R16, R20, R21 equates, R17, R22 is generally unsuitable excessive, with 1～10K resistance, because current transformer secondary current is less, therefore above electric capacity, resistance, inductance can meet power requirement with less encapsulation (06031/10W).Wherein, when unit,

$U_{\mathrm{IOP}\_\mathrm{POB}}=\frac{R13(U_{I+}-U_{I-})}{R4+R5}*\frac{R16}{R15+R16}+\frac{R15}{R15+R16}*3$

$U_{\mathrm{IOP}\_\mathrm{ERR}}=[-\frac{R18}{R12}\mathrm{UI}\_-+\frac{R9*R18*U_{I\_-}}{(R6+R7)*R11}]*\frac{R21}{R20+R21}+\frac{R20}{R20+R21}*3$

Because every parallel operation sample circuit is the same, therefore have when parallel operation

$U_{\mathrm{IOP}\_\mathrm{POB}}=-\frac{R13\left(U_{I+}-U_{I+}{U}_{\mathrm{IBUS}\_I+}-U_{\mathrm{IBUS}\_I-}\right)}{R4+R5}*\frac{R16}{R15+R16}+\frac{R15}{R15+R16}*3$

$U_{\mathrm{IOP}\_\mathrm{ERR}}=[-\frac{R18}{R12}{U}_{I\_}-+\frac{R9*R18*\left(U_{I\_-+}{U}_{\mathrm{IBUS}\_I-}\right)}{(R6+R7)*R11}]*\frac{R21}{R20+R21}+\frac{R20}{R20+R21}*3$

If described resistance, capacitance parameter before adopting, when unit

U _{iOP_ERR}=1.5, parallel operation is a fixing value by electric current circulation control signal when unit, is equivalent to no signal output.When parallel operation

$U_{\mathrm{IOP}\_\mathrm{POB}}=-\frac{U_{I+}-U_{I+}{U}_{\mathrm{IBUS}\_I+}-U_{\mathrm{IBUS}\_I-}}{2}+1.5,U_{\mathrm{IOP}\_\mathrm{ERR}}=\frac{U_{\mathrm{IBUS}\_I-}}{2}+1.5,$ The output current signal that while being parallel operation, parallel operation is sampled for another parallel operation by electric current circulation control signal, is sent to DSP and can participates in parallel operation current-sharing and circulation control.

The foregoing is only preferred embodiment of the present utility model; not thereby limit the scope of the claims of the present utility model; all equivalent structure or conversion of equivalent flow process that utilizes the utility model specification and accompanying drawing content to do; or be directly or indirectly used in other parallel operation current-sharing and circulation control technology field, be all in like manner included in scope of patent protection of the present utility model.

Claims (6)

1. a UPS parallel operation current sample switching control system, be connected with one or many UPS, it is characterized in that, comprise output current sample circuit, parallel operation current signal control circuit, change-over circuit and DSP control circuit, wherein output current sample circuit comprises current transformer, once the surveying and export that L line is connected and its secondary side is connected with the first input end of change-over circuit of described current transformer, described parallel operation current signal control circuit comprises relay and control relay circuit, the signal output part of described parallel operation current signal control circuit is connected with the second input of change-over circuit, the output of described change-over circuit is connected with DSP control circuit, so that output current sample circuit is just being exported, negative output current sampled signal (I_+, I_-) and parallel operation current signal control circuit just bring, negative parallel operation current signal (IBUS_I+, IBUS_I-) convert current sampling signal (IOP_POB) and parallel operation electric current circulation control signal (IOP_ERR) to and send into DSP control circuit.

2. UPS parallel operation current sample switching control system according to claim 1, it is characterized in that, described change-over circuit comprises the first anti-phase ratio amplifying circuit being connected with positive parallel operation current signal (IBUS_I+) input with positive output current sampling signal (I_+) input, described the first anti-phase ratio amplifying circuit rear end is connected with the first bleeder circuit and the first voltage follower in turn, described change-over circuit also comprises the second anti-phase ratio amplifying circuit being connected with negative parallel operation current signal (IBUS_I-) input with negative output current sampled signal (I_-) input, described the second anti-phase ratio amplifying circuit rear end is connected with the 3rd anti-phase ratio amplifying circuit in turn, the second bleeder circuit and second voltage follower, wherein said the 3rd anti-phase ratio amplifying circuit front end is also connected with negative parallel operation current signal (IBUS_I-) input with negative output current sampled signal (I_-) input.

3. UPS parallel operation current sample switching control system according to claim 1, it is characterized in that, the voltage signal of described current sampling signal (IOP_POB) for changing centered by 1.5VDC, described parallel operation use electric current circulation control signal (IOP_ERR) for the dead level of 1.5VDC, is the voltage signal changing centered by 1.5VDC in the time that UPS unit uses in the time that UPS parallel operation is used.

4. UPS parallel operation current sample switching control system according to claim 2, is characterized in that, described the first anti-phase ratio amplifying circuit, the second anti-phase ratio amplifying circuit and the 3rd anti-phase ratio amplifying circuit all adopt operational amplifier to form.

5. UPS parallel operation current sample switching control system according to claim 1, is characterized in that, described change-over circuit also comprises high-frequency filter circuit and common mode, differential mode filter circuit.

6. UPS parallel operation current sample switching control system according to claim 2, is characterized in that, described first, second bleeder circuit is to draw voltage branch circuit on 3.0VDC.