CN204514994U - A kind of imbalance of three-phase voltage protection module for soft starter - Google Patents
A kind of imbalance of three-phase voltage protection module for soft starter Download PDFInfo
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- CN204514994U CN204514994U CN201520086834.9U CN201520086834U CN204514994U CN 204514994 U CN204514994 U CN 204514994U CN 201520086834 U CN201520086834 U CN 201520086834U CN 204514994 U CN204514994 U CN 204514994U
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Abstract
The utility model relates to technical field of electric power, particularly relates to a kind of Voltage unbalance protection module.For an imbalance of three-phase voltage protection module for soft starter, comprise three-phase voltage signal input end, pressure-limit current-limit circuit, Zero-cross comparator testing circuit, imbalance of three-phase voltage testing circuit, output circuit.Imbalance of three-phase voltage testing circuit comprises voltage stabilizing diode D3 and adjustable resistance R21.The utility model defines the bound scope of non-equilibrium among three phase voltages by measures such as voltage stabilizing diode D3 and adjustable resistances, realize the judgement whether carrying out imbalance of three-phase voltage, both be applicable to underground coal mine soft start use, degree of unbalancedness can be made again to detect accurately, also have make simple, cost is low, reliability high.
Description
Technical field
The utility model relates to technical field of electric power, particularly relates to a kind of Voltage unbalance protection module.
Background technology
According to principle analysis, cause the reason of imbalance of three-phase voltage to have multiple, be mainly reflected in: the 1) imbalance of three-phase voltage of power supply system; 2) motor interior Xiang Zhi road virtual connection; 3) motor winding interturn short-circuit or shorted to earth; 4) wiring error etc.For protecting the safety of electrical equipment, Voltage unbalance protection must be added in underground coal mine soft initiator.
The current solution found is: 1) capacitances in series step-down, can drive middle decision circuitry that protection is exported when there being a phase phase shortage; 2) three-phase signal got by voltage transformer (VT), through signal transacting, through Chip Microcomputer A/D sampling, then calculates degree of unbalancedness, then carries out protection and export.This shows: method 1) can only protect 100% Voltage unbalance.Method 2) owing to adopting this nonlinear device of voltage transformer (VT) that degree of unbalancedness can be made to strengthen, add AD signal transacting, take a large amount of mcu resources.For this reason a kind ofly not only be applicable to underground mine use but also can have made degree of unbalancedness accurately and the imbalance of three-phase voltage protection module taking single-chip microcomputer less has just become the gordian technique of soft initiator.
Utility model content
The purpose of this utility model is, provides a kind of imbalance of three-phase voltage protection module for soft starter, to solve the problems of the technologies described above.
The technical matters that the utility model solves can realize by the following technical solutions:
A kind of imbalance of three-phase voltage protection module for soft starter, comprise three-phase voltage signal input end, also comprise the pressure-limit current-limit circuit be connected with described three-phase voltage signal input end, the Zero-cross comparator testing circuit be connected with described pressure-limit current-limit circuit, the imbalance of three-phase voltage testing circuit be connected with described Zero-cross comparator testing circuit, the output circuit that is connected with described imbalance of three-phase voltage testing circuit;
Described imbalance of three-phase voltage testing circuit comprises resistance R14, resistance R15, resistance R16, one end of described resistance R14, resistance R15, resistance R16 connects respectively compares Hou tri-road signal through described Zero-cross comparator testing circuit, one end of filter capacitor C6 is connected, the other end ground connection of described filter capacitor C6 after the other end of described resistance R14, resistance R15, resistance R16 links together;
The in-phase input end of comparer U2A, the inverting input of comparer U2B is also linked into after the other end of described resistance R14, resistance R15, resistance R16 links together;
Described imbalance of three-phase voltage testing circuit comprises 12VDC power output end, described 12VDC power output end is ground connection after contact resistance R19, resistance R20, voltage stabilizing diode D3 and adjustable resistance R21 successively, the inverting input of described comparer U2A, by electric capacity C5 ground connection, plays filtering, jamproof effect;
Also be connected with the inverting input of described comparer U2A between described resistance R20 and voltage stabilizing diode D3, also be connected with the in-phase input end of described comparer U2B between described voltage stabilizing diode D3 and adjustable resistance R21, the output terminal of described comparer U2A, the output terminal of described comparer U2B access described output circuit respectively.
The utility model can by the resistance of adjustment adjustable resistance R21, and make the in-phase input end level of comparer U2B be 4.6V, the inverting input level that can record comparer U2B is 6.7V, and these two level are as the bound level of imbalance of three-phase voltage.When voltage unbalance factor is no more than bound level range, normally work.Otherwise after voltage unbalance factor exceedes bound level range, output circuit is protected.Output circuit of the present utility model may be used for receiving topworks and protects, and also can receive single-chip microcomputer numeral mouth and judge.
The utility model is used for underground coal mine soft start, is suitable for the situation of electric pressure lower than 1140V (allowing overvoltage 130%Ue).The utility model defines the bound scope of non-equilibrium among three phase voltages by voltage stabilizing diode D3 and adjustable resistance R21, realizes the judgement whether carrying out imbalance of three-phase voltage.The utility model have make simple, cost is low, reliability high.
Described pressure-limit current-limit circuit can adopt existing pressure-limit current-limit circuit, also can adopt following pressure-limit current-limit circuit:
Described three-phase voltage signal input end is contact resistance R1, resistance R2, resistance R3 respectively, and described resistance R1 is ground connection after resistance R9, resistance R7, electric capacity C4; Described resistance R2 is ground connection after resistance R11, described resistance R7, described electric capacity C4; Described resistance R3 is ground connection after resistance R13, described resistance R7, described electric capacity C4, and described resistance R9, resistance R11, tie point between resistance R13 and described resistance R7 form insulated neutral.
Described Zero-cross comparator testing circuit can adopt existing Zero-cross comparator testing circuit, also can adopt following Zero-cross comparator testing circuit:
Described resistance R1 connects the in-phase input end of comparer U1B by resistance R4, by electric capacity C1 ground connection between the in-phase input end of described resistance R4 and described comparer U1B;
Described resistance R2 connects the in-phase input end of comparer U1D by resistance R5, by electric capacity C2 ground connection between the in-phase input end of described resistance R5 and described comparer U1D;
Described resistance R3 connects the in-phase input end of comparer U1C by resistance R6, by electric capacity C3 ground connection between the in-phase input end of described resistance R6 and described comparer U1C;
5V power output end is connected between described resistance R1 and resistance R4, by resistance R10 respectively by resistance R8 and is connected between described resistance R2 and resistance R5, is connected between described resistance R3 and resistance R6 by resistance R12;
Described neutral point connects the inverting input of described comparer U1B, the inverting input of described comparer U1D, the inverting input of described comparer U1C respectively by described resistance R7.The utility model makes the DC level between resistance R1 and resistance R4, between resistance R2 and resistance R5, between resistance R3 and resistance R6 rise to 5V by 5V power output end respectively, positive negative wave can be compared by current potential, obtain complete waveform.Neutral point is received as benchmark signal on the inverting input of three comparers through resistance R7 respectively, at three-phase voltage after relatively, realizes obtaining complete positive and negative waveform at the output terminal of three comparers.
5V power supply of the present utility model can be obtained by comparer power supply dividing potential drop:
Described 12VDC power output end is ground connection after resistance R17, resistance R18, the in-phase input end of comparer U1A is connected between described resistance R17 and resistance R18, the inverting input of described comparer U1A connects the output terminal of described comparer U1A, and the output terminal of described comparer U1A is as described 5V power output end.
Described output circuit can adopt existing output circuit, also can adopt following output circuit:
Described output circuit comprises rectification circuit, filtering circuit, described rectification circuit adopts commutation diode D1, commutation diode D2, the positive pole of described commutation diode D1 connects the output terminal of described comparer U2A, and the negative pole of described commutation diode D1 connects output protection end;
The positive pole of described commutation diode D2 connects the output terminal of described comparer U2B, and the negative pole of described commutation diode D2 also connects described output protection end;
Described filtering circuit adopts resistance R23, one end of electric capacity C7, described electric capacity C7 connects described output protection end, the other end ground connection of described electric capacity C7, and described resistance R23 is in parallel with described electric capacity C7.When voltage unbalance factor is no more than scope, output protection end output low level.Otherwise output protection end exports high level after voltage unbalance factor overruns, and can receive topworks and protect, also can receive single-chip microcomputer numeral mouth and judge.
The utility model is when circuit normally works, and non-equilibrium among three phase voltages permissible value is ± 2%, must not exceed in short-term ± 4%.When imbalance of three-phase voltage or after there is electric sampling open-phase, neutral point will offset, comparing, three superimposed after, when positive waveform comes, can boundary level 6.7V be exceeded.When negative wave comes, lower level 4.6V can be less than, thus make output protection end present high level, realize Voltage unbalance protection.When non-equilibrium among three phase voltages be less than ± 4% time, even if neutral point offsets, but be no more than bound level, thus make output present low level, can not protect.
Beneficial effect: owing to adopting technique scheme, what the utility model was less takies mcu resource, adopt rational circuit connecting relation, the bound scope of non-equilibrium among three phase voltages is defined by measures such as voltage stabilizing diode D3 and adjustable resistances, realize the judgement whether carrying out imbalance of three-phase voltage, both be applicable to underground coal mine soft start use, degree of unbalancedness can be made again to detect accurately, also have make simple, cost is low, reliability high.
Accompanying drawing explanation
Fig. 1 is a kind of circuit connection diagram of the present utility model;
Fig. 2 is the waveform of the wherein phase after superposition 5V power supply;
Fig. 3 is the waveform of the wherein phase compared with neutral point;
Fig. 4 is the waveform of the wherein phase after comparing with neutral point;
Fig. 5 is three superimposed filtered waveforms again, the waveform namely during three-phase voltage balance;
Fig. 6 is that tri-phase unbalance factor exceedes the ± waveform of 4%;
Fig. 7 is protection output waveform;
Fig. 8 is that tri-phase unbalance factor does not exceed ± the waveform of 4%.
Embodiment
The technological means realized to make the utility model, creation characteristic, reaching object and effect is easy to understand, setting forth the utility model further below in conjunction with concrete diagram.
With reference to Fig. 1, a kind of imbalance of three-phase voltage protection module for soft starter, comprises three-phase voltage signal input end J1, pressure-limit current-limit circuit, Zero-cross comparator testing circuit, imbalance of three-phase voltage testing circuit, output circuit.
1) pressure-limit current-limit circuit: comprise resistance R1, resistance R2, resistance R3, three-phase voltage is accessed by three-phase voltage signal input end J1, be respectively A phase, B phase and C phase, A phase is through resistance R1, resistance R9, B phase is through resistance R2, resistance R11, C phase after resistance R3, resistance R13, and A phase, B phase are connected with C phase, again through resistance R7, electric capacity C4 ground connection, composition insulated neutral N.
2) Zero-cross comparator testing circuit: after step-down current-limiting circuit, the 5V power supply of comparer U1A after 12VDC power supply dividing potential drop, through following, be added to A ' point respectively through resistance R8, resistance R10 is added to B ' point, resistance R12 is added to C ' point, the DC level of A ' B ' C ' 3 is risen to 5V, positive negative wave can be compared by current potential, obtain complete waveform.
A phase voltage through resistance R4, electric capacity C1 phase shift to the in-phase input end of comparer U1B, B phase voltage through resistance R5, electric capacity C2 phase shift to the in-phase input end of comparer U1D, C phase voltage through resistance R6, electric capacity C3 phase shift to the in-phase input end of comparer U1C.
Neutral point N point receives inverting input, the inverting input of comparer U1D, the inverting input of comparer U1C of comparer U1B, as the benchmark signal of three comparers respectively through R7.Three-phase voltage, after relatively, obtains complete positive and negative waveform at the output terminal of three comparers.
3) imbalance of three-phase voltage testing circuit: the positive and negative waveform signal of three-phase obtained from Zero-cross comparator testing circuit is at Signal averaging after resistance R14, resistance R15, resistance R16, filter capacitor C6 makes P point reference level be the sawtooth wave of 5.65V, and is linked into the in-phase input end of comparer U2A, the inverting input of comparer U2B respectively.12VDC power output end is ground connection after contact resistance R19, resistance R20, voltage stabilizing diode D3 and adjustable resistance R21 successively.D3 adopts 2.1V voltage stabilizing diode.Be connected with the inverting input of comparer U2A between resistance R20 and voltage stabilizing diode D3, be connected with the in-phase input end of comparer U2B between voltage stabilizing diode D3 and adjustable resistance R21.The inverting input of comparer U2A, also by electric capacity C5 ground connection, plays Anti-Jamming, makes boundary level more steady.
The resistance of adjustment adjustable resistance R21, the in-phase input end level making comparer U2B is 4.6V, and the inverting input level recording comparer U2B is 6.7V, and these two level are as the bound level of imbalance of three-phase voltage.When voltage unbalance factor is no more than bound level range, normally work.Otherwise after voltage unbalance factor exceedes bound level range, output circuit is protected.
4) output circuit: comprise rectification circuit, filtering circuit.The output terminal that rectification circuit adopts commutation diode D1, the positive pole of commutation diode D2, commutation diode D1 connects comparer U2A, the negative pole of commutation diode D1 connects output protection end.The positive pole of commutation diode D2 connects the output terminal of comparer U2B, and the negative pole of commutation diode D2 also connects output protection end.Filtering circuit adopts resistance R23, one end of electric capacity C7, electric capacity C7 connects output protection end, and the other end ground connection of electric capacity C7, resistance R23 is in parallel with electric capacity C7.When voltage unbalance factor is no more than scope, output protection end output low level.Otherwise output protection end exports high level after voltage unbalance factor overruns, and can receive topworks and protect, also can receive single-chip microcomputer numeral mouth and judge.
When adopting the utility model to be used for the imbalance of three-phase voltage protection module of underground coal mine soft start, the waveform of the wherein phase after three-phase voltage signal superposition 5V power supply as shown in Figure 2.With reference to Fig. 3, for the waveform of a wherein phase that compares with neutral point N point as shown in Figure 3.Fig. 4 is the wherein phase waveform after adopting comparer three-phase voltage and neutral point N point to be compared.With reference to Fig. 5, the positive and negative waveform signal of three-phase obtained from Zero-cross comparator testing circuit at Signal averaging after resistance R14, resistance R15, resistance R16, then is sawtooth wave through the waveform of the filtered P point of filter capacitor C6, and Fig. 5 is the waveform of three-phase voltage when balancing.And be that tri-phase unbalance factor exceedes the ± waveform of 4% with reference to Fig. 6.Protected by output circuit of the present utility model, the waveform that reference Fig. 7 output protection end exports as shown in Figure 7.With reference to Fig. 8, when tri-phase unbalance factor do not exceed ± 4% time, output protection end presents low level, can not protect.
Visible, when circuit normally works, non-equilibrium among three phase voltages permissible value is ± 2%, must not exceed in short-term ± 4%.When imbalance of three-phase voltage or after there is electric sampling open-phase, neutral point will offset, comparing, three superimposed after, when positive waveform comes, can boundary level 6.7V be exceeded.When negative wave comes, lower level 4.6V can be less than, thus make output protection end present high level, realize Voltage unbalance protection.When non-equilibrium among three phase voltages be less than ± 4% time, even if neutral point offsets, but be no more than bound level, thus make output present low level, can not protect.
More than show and describe ultimate principle of the present utility model and principal character and advantage of the present utility model.The technician of the industry should understand; the utility model is not restricted to the described embodiments; what describe in above-described embodiment and instructions just illustrates principle of the present utility model; under the prerequisite not departing from the utility model spirit and scope; the utility model also has various changes and modifications, and these changes and improvements all fall within the scope of claimed the utility model.The claimed scope of the utility model is defined by appending claims and equivalent thereof.
Claims (6)
1. the imbalance of three-phase voltage protection module for soft starter, comprise three-phase voltage signal input end, it is characterized in that, also comprise the pressure-limit current-limit circuit be connected with described three-phase voltage signal input end, the Zero-cross comparator testing circuit be connected with described pressure-limit current-limit circuit, the imbalance of three-phase voltage testing circuit be connected with described Zero-cross comparator testing circuit, the output circuit that is connected with described imbalance of three-phase voltage testing circuit;
Described imbalance of three-phase voltage testing circuit comprises resistance R14, resistance R15, resistance R16, one end of described resistance R14, resistance R15, resistance R16 connects respectively compares Hou tri-road signal through described Zero-cross comparator testing circuit, by filter capacitor C6 ground connection after the other end of described resistance R14, resistance R15, resistance R16 links together;
The in-phase input end of comparer U2A, the inverting input of comparer U2B is also linked into after the other end of described resistance R14, resistance R15, resistance R16 links together;
12VDC power output end is ground connection after contact resistance R19, resistance R20, voltage stabilizing diode D3 and adjustable resistance R21 successively, also be connected with the inverting input of described comparer U2A between described resistance R20 and voltage stabilizing diode D3, also be connected with the in-phase input end of described comparer U2B between described voltage stabilizing diode D3 and adjustable resistance R21, the output terminal of described comparer U2A, the output terminal of described comparer U2B access described output circuit respectively.
2. a kind of imbalance of three-phase voltage protection module for soft starter according to claim 1, is characterized in that, the inverting input of described comparer U2A is also by electric capacity C5 ground connection.
3. a kind of imbalance of three-phase voltage protection module for soft starter according to claim 1, it is characterized in that, described pressure-limit current-limit circuit comprises resistance R1, resistance R2, resistance R3, described three-phase voltage signal input end connects described resistance R1, resistance R2, resistance R3 respectively, and described resistance R1 is ground connection after resistance R9, resistance R7, electric capacity C4; Described resistance R2 is ground connection after resistance R11, described resistance R7, described electric capacity C4; Described resistance R3 is ground connection after resistance R13, described resistance R7, described electric capacity C4, and described resistance R9, resistance R11, tie point between resistance R13 and described resistance R7 form insulated neutral.
4. a kind of imbalance of three-phase voltage protection module for soft starter according to claim 3, it is characterized in that, described Zero-cross comparator testing circuit comprises resistance R4, resistance R5, resistance R6,
Described resistance R1 connects the in-phase input end of comparer U1B by described resistance R4, by electric capacity C1 ground connection between the in-phase input end of described resistance R4 and described comparer U1B;
Described resistance R2 connects the in-phase input end of comparer U1D by described resistance R5, by electric capacity C2 ground connection between the in-phase input end of described resistance R5 and described comparer U1D;
Described resistance R3 connects the in-phase input end of comparer U1C by described resistance R6, by electric capacity C3 ground connection between the in-phase input end of described resistance R6 and described comparer U1C;
5V power output end is connected between described resistance R1 and resistance R4, by resistance R10 respectively by resistance R8 and is connected between described resistance R2 and resistance R5, is connected between described resistance R3 and resistance R6 by resistance R12;
Described neutral point connects the inverting input of described comparer U1B, the inverting input of described comparer U1D, the inverting input of described comparer U1C respectively by described resistance R7.
5. a kind of imbalance of three-phase voltage protection module for soft starter according to claim 4; it is characterized in that; described 12VDC power output end is ground connection after resistance R17, resistance R18; the in-phase input end of comparer U1A is connected between described resistance R17 and resistance R18; the inverting input of described comparer U1A connects the output terminal of described comparer U1A, and the output terminal of described comparer U1A is as described 5V power output end.
6. a kind of imbalance of three-phase voltage protection module for soft starter as claimed in any of claims 1 to 4, it is characterized in that, described output circuit comprises rectification circuit, filtering circuit, described rectification circuit adopts commutation diode D1, commutation diode D2, the positive pole of described commutation diode D1 connects the output terminal of described comparer U2A, and the negative pole of described commutation diode D1 connects output protection end;
The positive pole of described commutation diode D2 connects the output terminal of described comparer U2B, and the negative pole of described commutation diode D2 also connects described output protection end;
Described filtering circuit adopts resistance R23, one end of electric capacity C7, described electric capacity C7 connects described output protection end, the other end ground connection of described electric capacity C7, and described resistance R23 is in parallel with described electric capacity C7.
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| Application Number | Priority Date | Filing Date | Title |
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| CN201520086834.9U CN204514994U (en) | 2015-02-06 | 2015-02-06 | A kind of imbalance of three-phase voltage protection module for soft starter |
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| CN201520086834.9U CN204514994U (en) | 2015-02-06 | 2015-02-06 | A kind of imbalance of three-phase voltage protection module for soft starter |
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| CN204514994U true CN204514994U (en) | 2015-07-29 |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107528295A (en) * | 2017-09-29 | 2017-12-29 | 中国西电电气股份有限公司 | A kind of three-phase protective circuit and method for VSC |
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Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107528295A (en) * | 2017-09-29 | 2017-12-29 | 中国西电电气股份有限公司 | A kind of three-phase protective circuit and method for VSC |
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