CN203522156U - Phase current balance protection circuit of automobile frequency converter - Google Patents
Phase current balance protection circuit of automobile frequency converter Download PDFInfo
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- CN203522156U CN203522156U CN201320670861.1U CN201320670861U CN203522156U CN 203522156 U CN203522156 U CN 203522156U CN 201320670861 U CN201320670861 U CN 201320670861U CN 203522156 U CN203522156 U CN 203522156U
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Abstract
The utility model provides a phase current balance protection circuit of an automobile frequency converter. The protection circuit comprises a current transformer used for acquiring load three-phase current of the frequency converter, and is characterized by further comprising a signal conditioning circuit, an adder, a positive reference generation circuit, a negative reference generation circuit, a positive threshold comparison circuit, a negative threshold comparison circuit and a gate circuit. According to the utility model, when the load of the automobile frequency converter works, the current transformer is used for acquiring A, B and C three-phase current signals, and performing superposing of the signals, then comparison is performed on voltages generated through superposing, when phase currents are not balanced or faults occur, after deviation voltages are compared with normal voltages, protection signals are outputted for directly turning off the hardware output of the frequency converter. Compared to other circuits which employ software for determining and executing output, the protection circuit provided by the utility model has the advantages of high reliability, high anti-interference capability, fast output speed and the like.
Description
Technical field
The utility model relates to electric powered motor and controls and detection technique field, specifically a kind of phase current balanced protection circuit of automobile frequency converter.
Background technology
Three large key technologies of electric automobile comprise motor, battery and electronic control technology now, and wherein electronic control technology comprises car load control and electric machines control technology.Automobile frequency converter is one of kernel component of realizing motor in electric automobile control, and the reliability of its work is directly connected to the overall performance of car load and the handling and fail safe of vehicle etc.In order to guarantee the Performance And Reliability of frequency converter, meet fast the requirement of control and protection in real time, the functions such as the software and hardware of frequency converter needs to possess current-limiting protection, overcurrent and overvoltage protection in design process, shorted to earth protection and overload protection.
Conventional frequency converter is due to factors such as cost and volume restrictions; generally according to the current signal of the frequency converter external load gathering; by software, judge whether electric current exists overcurrent, phase shortage, phase current imbalance etc. abnormal; if exist extremely, software again output protection signal turn-offs the output of frequency converter or stops corresponding software output.Adopt software judge the phase current of frequency converter need to sample through overcurrent signal, processor calculating obtains judged result, processor is exported the stages such as control signal, actuator action; antijamming capability a little less than; control signal output speed is slower; in requiring high occasion and environment, easily occur protection problem not in time, reliability is lower.
Utility model content
The purpose of this utility model is to provide a kind of phase current balanced protection circuit of automobile frequency converter, and when the current anomaly of frequency converter external load, the output that can turn-off in time frequency converter, effectively protects frequency converter, and it is normally worked.
The technical solution of the utility model is:
A kind of phase current balanced protection circuit of automobile frequency converter, comprise for gathering the current transformer of inverter load three-phase current, also comprise signal conditioning circuit, adder, forward reference data generative circuit, negative sense reference data generative circuit, positive threshold comparison circuit, negative sense threshold value comparison circuit and AND circuit;
The output of described current transformer is connected with the input of adder by signal conditioning circuit, the output of described adder is connected with the in-phase input end of negative sense threshold value comparison circuit with the inverting input of positive threshold comparison circuit, the in-phase input end of described positive threshold comparison circuit is connected with the output of forward reference data generative circuit, and the inverting input of described negative sense threshold value comparison circuit is connected with the output of negative sense reference data generative circuit;
The output of described positive threshold comparison circuit is connected the input of AND circuit with the output of negative sense threshold value comparison circuit, the output of described AND circuit is connected with the hardware protection circuit of frequency converter.
The phase current balanced protection circuit of described automobile frequency converter, described current transformer comprises A phase current mutual inductor, B phase current mutual inductor and C phase current mutual inductor, and described signal conditioning circuit comprises A phase signals modulate circuit, B phase signals modulate circuit and C phase signals modulate circuit;
The output of described A phase current mutual inductor is connected with the input of adder by A phase signals modulate circuit, the output of described B phase current mutual inductor is connected with the input of adder by B phase signals modulate circuit, and the output of described C phase current mutual inductor is connected with the input of adder by C phase signals modulate circuit.
The phase current balanced protection circuit of described automobile frequency converter, also comprises firstorder filter, and described adder is connected with negative sense threshold value comparison circuit with positive threshold comparison circuit by firstorder filter.
The phase current balanced protection circuit of described automobile frequency converter, described forward reference data generative circuit comprises power supply and voltage reference chip, the output of described power supply is connected with the in-phase input end of positive threshold comparison circuit by voltage reference chip.
The phase current balanced protection circuit of described automobile frequency converter; described negative sense reference data generative circuit comprises power supply, voltage reference chip and inverting amplifier; the output of described power supply is connected with the input of inverting amplifier by voltage reference chip, and the output of described inverting amplifier is connected with the inverting input of negative sense threshold value comparison circuit.
The utility model is when load (three phase alternating current motor) work of automobile frequency converter; by high precision current transformer, gather A, B, C three-phase current signal; and it is superposeed; the voltage again stack being generated compares; when phase current is uneven or break down; after its deviation voltage and normal voltage compare; export a guard signal; be used for directly turn-offing the hardware output of frequency converter; with respect to other, by software, judged and carry out the circuit of output; the advantages such as have reliability high, antijamming capability is strong, and output speed is fast.
Accompanying drawing explanation
Fig. 1 is structural representation of the present utility model;
Fig. 2 is forward reference data generative circuit schematic diagram;
Fig. 3 is negative sense reference data generative circuit schematic diagram.
Embodiment
As shown in Figure 1; a phase current balanced protection circuit for automobile frequency converter, comprises A phase current mutual inductor 1, B phase current mutual inductor 2, C phase current mutual inductor 3, A phase signals modulate circuit 4, B phase signals modulate circuit 5, C phase signals modulate circuit 6, adder 7, firstorder filter 8, forward reference data generative circuit 9, negative sense reference data generative circuit 10, positive threshold comparison circuit 11, negative sense threshold value comparison circuit 12 and AND circuit 13.Positive threshold comparison circuit 11 and negative sense threshold value comparison circuit 12 are the voltage comparator circuit with two voltage inputs.
A phase current mutual inductor 1, B phase current mutual inductor 2 and C phase current mutual inductor 3 are respectively used to gather A, B, the C three-phase current of inverter load.The output of A phase current mutual inductor 1 is connected with the input of A phase signals modulate circuit 4, and the output of A phase signals modulate circuit 4 is connected with the input of adder 7; The output of B phase current mutual inductor 2 is connected with the input of B phase signals modulate circuit 5, and the output of B phase signals modulate circuit 5 is connected with the input of adder 7; The output of C phase current mutual inductor 3 is connected with the input of C phase signals modulate circuit 6, and the output of C phase signals modulate circuit 6 is connected with the input of adder 7.
The output of adder 7 is connected with the input of firstorder filter 8, and the output of firstorder filter 8 is connected with the in-phase input end of negative sense threshold value comparison circuit 12 with the inverting input of positive threshold comparison circuit 11 respectively.The in-phase input end of positive threshold comparison circuit 11 is connected with the output of forward reference data generative circuit 9, and the inverting input of negative sense threshold value comparison circuit 12 is connected with the output of negative sense reference data generative circuit 10.The output of positive threshold comparison circuit 11 is connected the input of AND circuit 13 with the output of negative sense threshold value comparison circuit 12, the output of AND circuit 13 be connected with the hardware protection circuit of rear class frequency converter.
Figure 2 shows that the generative circuit of forward reference data voltage, supply voltage VCC is through current-limiting resistance R1 current limliting, through voltage reference chip Q1, carry out voltage stabilizing again, just obtain a source of stable pressure, source of stable pressure output positive voltage VO is to the in-phase input end of positive threshold comparison circuit 11.
Figure 3 shows that the generative circuit of negative sense reference data voltage, supply voltage VCC is through current-limiting resistance R1 current limliting, through voltage reference chip Q1, carry out voltage stabilizing again, obtain a source of stable pressure, due to voltage reference chip, Q1 can not produce negative voltage, so source of stable pressure is connected with inverting amplifier, the positive voltage that source of stable pressure is exported is after inverting amplifier carries out 1:1 amplification, produce negative voltage VO, export the inverting input of negative sense threshold value comparison circuit 12 to; Inverting amplifier is comprised of resistance R 2, R3, R4, R5, capacitor C 2, C3 and comparator U1.This mode has been utilized the anti-phase amplification principle of amplifier, directly the positive voltage of input is carried out to ratio amplification, because the positive voltage of inputting is through voltage stabilizing, so the negative voltage of output is also very stable.
Operation principle of the present utility model:
The load three phase alternating current motor of automobile frequency converter is when work, and its A, B, C three-phase current are after high-precision current transformer sampling, at three voltage signals that change with load current of secondary generation of current transformer; These three voltage signals, after signal conditioning circuit carries out signal condition, become the voltage signal being of moderate size, then are input to adder and carry out voltage stack.Under normal circumstances, when A, B, C threephase load current balance type and equal and opposite in direction, three voltage signals that are input to adder are that frequency is identical, the sinusoidal signal of phase phasic difference 120 degree, its instantaneous stack component is 0, when A, B, C threephase load current imbalance or phase shortage, the superimposed voltage that is input to three voltage signals of adder shows as positive voltage or negative voltage state.The superimposed voltage being generated by adder is carried out filtering through firstorder filter, remove high frequency and ripple component wherein, become DC voltage component, this DC voltage component is input to respectively the inverting input of positive threshold comparison circuit and the in-phase input end of negative sense threshold value comparison circuit.When the voltage of firstorder filter output is that positive voltage and this positive voltage are while being greater than forward reference data voltage, forward threshold values comparison circuit output protection signal (low level), when the voltage of firstorder filter output is that negative voltage and this negative voltage are while being less than negative sense reference data voltage, negative sense threshold values comparison circuit output protection signal (low level), the guard signal of positive threshold comparison circuit or the output of negative sense threshold value comparison circuit is through AND circuit, export a control signal (low level), this control signal transfers to the hardware protection circuit of frequency converter, turn-off the output of frequency converter, prevent the further expansion of fault.
For example, set that forward reference data voltage is 0.3, negative sense reference data voltage is-0.3:
When the voltage of firstorder filter output is 0.2 or-0.2, concerning positive threshold comparison circuit, the input of in-phase input end (0.3) is greater than the input (0.2 or-0.2) of inverting input, therefore positive threshold comparison circuit is output as high level; Concerning negative sense threshold value comparison circuit, the input of in-phase input end (0.2 or-0.2) is greater than the input (0.3) of inverting input, therefore the output of negative sense threshold value comparison circuit is also high level; Thereby AND circuit is output as high level, after the inverter of follow-up hardware protection circuit, be output as low level, cannot cut off follow-up hardware protection circuit.
When the voltage of firstorder filter output is 0.6, concerning positive threshold comparison circuit, the input of in-phase input end (0.3) is less than the input (0.6) of inverting input, therefore positive threshold comparison circuit is output as low level; Concerning negative sense threshold value comparison circuit, the input of in-phase input end (0.6) is greater than the input (0.3) of inverting input, therefore negative sense threshold value comparison circuit is output as high level; Thereby AND circuit is output as low level, after the inverter of follow-up hardware protection circuit, be output as high level, cut off follow-up hardware protection circuit, turn-off the output of frequency converter.
When the voltage of firstorder filter output is-0.6, concerning positive threshold comparison circuit, the input of in-phase input end (0.3) is greater than the input (0.6) of inverting input, therefore positive threshold comparison circuit is output as high level; Concerning negative sense threshold value comparison circuit, the input of in-phase input end (0.6) is less than the input (0.3) of inverting input, therefore negative sense threshold value comparison circuit is output as low level; Thereby AND circuit is output as low level, after the inverter of follow-up hardware protection circuit, be output as high level, cut off follow-up hardware protection circuit, turn-off the output of frequency converter.
The above execution mode is only that preferred implementation of the present utility model is described; not scope of the present utility model is limited; do not departing under the prerequisite of the utility model design spirit; various distortion and improvement that those of ordinary skills make the technical solution of the utility model, all should fall in the definite protection range of claims of the present utility model.
Claims (5)
1. the phase current balanced protection circuit of an automobile frequency converter, comprise for gathering the current transformer of inverter load three-phase current, it is characterized in that: also comprise signal conditioning circuit, adder, forward reference data generative circuit, negative sense reference data generative circuit, positive threshold comparison circuit, negative sense threshold value comparison circuit and AND circuit;
The output of described current transformer is connected with the input of adder by signal conditioning circuit, the output of described adder is connected with the in-phase input end of negative sense threshold value comparison circuit with the inverting input of positive threshold comparison circuit, the in-phase input end of described positive threshold comparison circuit is connected with the output of forward reference data generative circuit, and the inverting input of described negative sense threshold value comparison circuit is connected with the output of negative sense reference data generative circuit;
The output of described positive threshold comparison circuit is connected the input of AND circuit with the output of negative sense threshold value comparison circuit, the output of described AND circuit is connected with the hardware protection circuit of frequency converter.
2. the phase current balanced protection circuit of automobile frequency converter according to claim 1, it is characterized in that: described current transformer comprises A phase current mutual inductor, B phase current mutual inductor and C phase current mutual inductor, described signal conditioning circuit comprises A phase signals modulate circuit, B phase signals modulate circuit and C phase signals modulate circuit;
The output of described A phase current mutual inductor is connected with the input of adder by A phase signals modulate circuit, the output of described B phase current mutual inductor is connected with the input of adder by B phase signals modulate circuit, and the output of described C phase current mutual inductor is connected with the input of adder by C phase signals modulate circuit.
3. the phase current balanced protection circuit of automobile frequency converter according to claim 1, is characterized in that: also comprise firstorder filter, described adder is connected with negative sense threshold value comparison circuit with positive threshold comparison circuit by firstorder filter.
4. the phase current balanced protection circuit of automobile frequency converter according to claim 1; it is characterized in that: described forward reference data generative circuit comprises power supply and voltage reference chip, and the output of described power supply is connected with the in-phase input end of positive threshold comparison circuit by voltage reference chip.
5. the phase current balanced protection circuit of automobile frequency converter according to claim 1; it is characterized in that: described negative sense reference data generative circuit comprises power supply, voltage reference chip and inverting amplifier; the output of described power supply is connected with the input of inverting amplifier by voltage reference chip, and the output of described inverting amplifier is connected with the inverting input of negative sense threshold value comparison circuit.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320670861.1U CN203522156U (en) | 2013-10-29 | 2013-10-29 | Phase current balance protection circuit of automobile frequency converter |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201320670861.1U CN203522156U (en) | 2013-10-29 | 2013-10-29 | Phase current balance protection circuit of automobile frequency converter |
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| CN203522156U true CN203522156U (en) | 2014-04-02 |
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201320670861.1U Expired - Fee Related CN203522156U (en) | 2013-10-29 | 2013-10-29 | Phase current balance protection circuit of automobile frequency converter |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560491A (en) * | 2013-10-29 | 2014-02-05 | 安徽安凯汽车股份有限公司 | Circuit and method for protecting phase current balance of automobile frequency converter |
| CN105071349A (en) * | 2015-09-09 | 2015-11-18 | 广东科动电气技术有限公司 | Converter over-current protection and automatic reset circuit |
-
2013
- 2013-10-29 CN CN201320670861.1U patent/CN203522156U/en not_active Expired - Fee Related
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103560491A (en) * | 2013-10-29 | 2014-02-05 | 安徽安凯汽车股份有限公司 | Circuit and method for protecting phase current balance of automobile frequency converter |
| CN103560491B (en) * | 2013-10-29 | 2017-10-24 | 安徽安凯汽车股份有限公司 | A kind of phase current balanced protection circuit of automobile frequency converter and guard method |
| CN105071349A (en) * | 2015-09-09 | 2015-11-18 | 广东科动电气技术有限公司 | Converter over-current protection and automatic reset circuit |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140402 Termination date: 20171029 |