CN203761026U - Transformer overcurrent protection system - Google Patents
Transformer overcurrent protection system Download PDFInfo
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- CN203761026U CN203761026U CN201420026389.2U CN201420026389U CN203761026U CN 203761026 U CN203761026 U CN 203761026U CN 201420026389 U CN201420026389 U CN 201420026389U CN 203761026 U CN203761026 U CN 203761026U
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- voltage signal
- transformer
- protection system
- overcurrent protection
- sampled voltage
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Abstract
The utility model provides a transformer overcurrent protection system, which comprises a signal acquisition unit, a processor and an execution unit, wherein the signal acquisition unit is used for acquiring sampling voltage signals corresponding to the magnitude of the grounding current; the processor is used for acquiring a grounding current value according to the sampling voltage signals and the processor sends a stop command when the grounding current value exceeds the preset current threshold; and the execution unit stops operation of the transformer. The transformer overcurrent protection system can prevent the transformer from being damaged.
Description
Technical field
The utility model belongs to field transformer, is specifically related to a kind of transformer overcurrent protection system.
Background technology
Power transformer is one of electric equipment important in electric power system, if power transformer breaks down, not only can damage power transformer self, and can cause damage to user, affects the normal production of people and life.In order to prevent power transformer from breaking down, cause damage, conventionally by the iron core single-point grounding of transformer.When power transformer normally moves, earth current is between several milliamperes to tens milliamperes.When power transformer breaks down, earth current can be over tens amperes.Therefore, by measuring the size of earth current, can judge whether power transformer operation is normal.
In the transformer overcurrent protection system of using at present, when earth current overrun, transformer overcurrent protection system gives the alarm, and monitor staff should check power transformer.Affect the many factors that earth current changes, earth current occurs that the situation of fluctuation is comparatively frequent, and is difficult to the position that location causes earth current fluctuation.Therefore, in actual applications, although earth current has surpassed normal range (NR), and transformer overcurrent protection system also sent warning, and monitor staff is unable to fix a breakdown, and can cause transformer to damage when serious.
Utility model content
The technical problems to be solved in the utility model is exactly the above-mentioned defect existing in existing transformer overcurrent protection system, and a kind of transformer overcurrent protection system is provided, and it can avoid transformer to damage.
For this reason, the utility model provides a kind of transformer overcurrent protection system, for the protection of transformer, normally moves, and comprising:
Signal gathering unit, for obtaining the sampled voltage signal corresponding with earth current size;
Processor, for according to described sampled voltage signal acquisition earth current value, and when described earth current value surpasses predetermined current threshold value, sends execution instruction;
Performance element, carries out corresponding operation for the described execution instruction of sending according to described processor;
The time that described processor surpasses predetermined current threshold value in described earth current value is sent suspended market order while being greater than Preset Time, and described performance element is ended transformer operation.
Wherein, described processor is sending operating instruction after Preset Time, described performance element starting transformer.
Wherein, described processor sends alarm command when described earth current value surpasses described predetermined current threshold value, and described performance element is carried out alarm command.
Wherein, also comprise:
Signal processing unit, for the treatment of described sampled voltage signal;
Sampling analysis unit, for obtaining effective value and the peak value of described sampled voltage signal first-harmonic and harmonic wave, and obtains effective value and the peak value of described sampled signal.
Wherein, described signal processing unit comprises:
Control amplification module, for controlling, amplify described sampled voltage signal;
Filtration module, carries out filtering for the described sampled voltage signal to after amplifying.
Wherein, described sampling analysis unit comprises:
Data sampling module, for obtaining effective value and the peak value of described sampled voltage signal first-harmonic and/or harmonic wave;
Data analysis module, for obtaining effective value and the peak value of described sampled voltage signal according to the effective value of first-harmonic and/or harmonic wave and peak value.
Wherein, described processor obtains described earth current value according to the effective value of described sampled voltage signal and peak value.
Wherein, described signal gathering unit comprises:
Band magnetic gap coil, for zero magnetic flux balance with the sampler space is provided;
Magnetic Sensor, is located at the described magnetic gap position with magnetic gap coil, by responding to the magnetic field of magnetic gap position, obtains induced voltage signal;
Differential operational amplifier, for converting described induced voltage signal to single-ended voltage signal;
Electric current and voltage converting unit, for converting described single-ended voltage signal to current signal, and by the described winding with magnetic gap coil of described current signal input;
Pressure resistance, is connected between described winding and ground with magnetic gap coil, in order to obtain resistance voltage signal;
Low noise operational amplifier, its input is connected with described pressure resistance one end away from ground connection, output is connected with described signal processing unit, and described low noise operational amplifier is used for amplifying described resistance voltage signal and obtains sampled voltage signal, and impedance transformation is provided.
Wherein, described Magnetic Sensor is GMR Magnetic Sensor TMR Magnetic Sensor.
Wherein, also comprise:
Communication unit, for the communication between described processor and host computer or CSRC platform;
Power Management Unit, for providing electric energy;
Control unit, for the input interface of man-machine interaction is provided;
Display unit, for providing the interface of man-machine interaction;
Memory cell, for storing the real-time waveform data of described sampled voltage signal, the effective value of sampled voltage signal and peak value, the first-harmonic of sampled voltage signal and the effective value of harmonic wave and peak value.
The utlity model has following beneficial effect:
The transformer overcurrent protection system that the utility model provides; processor surpasses predetermined current threshold value in earth current value; and the time that surpasses predetermined current threshold value send suspended market order while being greater than Preset Time; performance element is received the operation of ending transformer after the suspended market order of processor; this is not only conducive to staff and fixes a breakdown; and be conducive to transformer Cooling cooling, thereby avoid transformer to damage.
Because transformer temperature is too high, also can cause earth current fluctuation, preferably, after ending transformer operation, processor sends operating instruction after Preset Time, and performance element restarts transformer.
Accompanying drawing explanation
Fig. 1 provides the theory diagram of transformer overcurrent protection system for the present embodiment;
Fig. 2 is the schematic diagram of the utility model embodiment signal gathering unit;
Fig. 3 is the theory diagram of the utility model embodiment signal processing unit;
Fig. 4 is the theory diagram of the utility model embodiment sampling analysis unit.
Embodiment
For making those skilled in the art understand better the technical solution of the utility model, transformer overcurrent protection system the utility model being provided below in conjunction with accompanying drawing is described in detail.
As shown in Figure 1, transformer overcurrent protection system comprises signal gathering unit 1, signal processing unit 2, sampling analysis unit 3, processor 4 and performance element 5.
Wherein, signal gathering unit 1 is for obtaining sampled voltage signal corresponding to earth current size.Signal processing unit 2 is for processing sampled voltage signal.Sampling analysis unit 3 is for obtaining effective value and the peak value of sampled voltage signal first-harmonic and/or harmonic wave, and obtains effective value and the peak value of sampled signal.Processor 4 is for obtaining earth current value according to the effective value of sampled voltage signal and peak value, and comparison earth current and predetermined current threshold value, when earth current value surpasses predetermined current threshold value, sends execution instruction.Performance element 5 is carried out corresponding operation for the execution instruction of sending according to processor.Performance element 5 comprises alarm module and/or ends module.Alarm module is carried out alarm command, ends module and carries out suspended market order and enabled instruction.
Signal gathering unit 1 adopts the magnetic balance current measurement pattern of closed loop feedback, and this metering system isolation is high, highly sensitive, and the linearity is good, and dynamic range is large.As shown in Figure 2, signal gathering unit 1 comprises band magnetic gap coil 11, Magnetic Sensor 12, differential operational amplifier 13, electric current and voltage converting unit 14, pressure resistance 15 and low noise operational amplifier 16.
Wherein, be with magnetic gap coil 11 for zero magnetic flux balance and the sampler space is provided.With magnetic gap coil 11, comprise magnetic core 111 and the winding 112 that is wrapped in magnetic core 111 peripheries, magnetic core 111 is provided with magnetic gap 113.Wherein, magnetic core 111 adopts high permeability materials to make, and the number of turn of winding 112 is between 1000～3000 circles, and the width of magnetic gap is less than 5mm.During use, iron core grounding wire, through band magnetic gap coil 11 center, is about to be placed on magnetic gap coil 11 outside of iron core grounding wire.For ease of installing, band magnetic gap coil 11 adopts Split type structure, is with magnetic gap coil 11 to be comprised of two parts.During use, two parts are fixed together, form band gap helical coil 11.
Magnetic Sensor 12 is arranged at magnetic gap 113 positions with magnetic gap coil 11, for the magnetic field by induction magnetic gap position, obtains induced voltage signal.Magnetic Sensor 12 can adopt GMR Magnetic Sensor or TMR Magnetic Sensor.GMR Magnetic Sensor comprises the Wheatstone bridge consisting of magnetic induction film or the impedance component consisting of magnetic induction film.GMR Magnetic Sensor or TMR Magnetic Sensor is highly sensitive, the linearity good, dynamic range is large, frequency response is fast and temperature stability is good.
Differential operational amplifier 13 is for converting induced voltage signal to single-ended voltage signal.Differential operational amplifier 13 adopts low noise zero shift differential operational amplifier.
Electric current and voltage converting unit 14 is for converting single-ended voltage signal to current signal, and is electrically connected to the winding 112 with magnetic gap coil 11, with by the winding 112 of current signal input tape magnetic gap coil 11.
Pressure resistance 15 is connected between the winding and ground with magnetic gap coil, in order to obtain resistance voltage signal.The resistance of the present embodiment pressure resistance 15 is 100 Europe, and precision is 0.1%.Because measured signal scope is 0.1mA～10A, if the number of turn of winding 112 is 1000 circles, the drive current range in winding 112 is 0.1 μ A～10mA, and the noise current in circuit is not more than 0.1 μ A so, and voltage noise is not more than 10uV.Therefore, when selecting device, should meet above-mentioned two conditions.
The input of low noise operational amplifier 16 is connected with pressure resistance 15 one end away from ground connection, the output of low noise operational amplifier 16 as the output of signal gathering unit 1 with shown in signal processing unit 2(Fig. 1) be connected, low noise operational amplifier 16 is for amplifying resistance voltage signal to obtain sampled voltage signal, and impedance transformation is provided.
In conjunction with reference to shown in figure 1 and Fig. 3, signal processing unit 2 comprises controls amplification module 21 and filtration module 22.Wherein, control the sampled voltage signal that amplification module 21 obtains for controlling amplifying signal collecting unit 1.The multiplication factor of controlling amplification module 21 can be made as 1 times or 100 times as required.
Filtration module 22 carries out filtering for the sampled voltage signal to after amplifying.Filtration module 22 filtering out-of-band noises, improve signal to noise ratio.As adopting 4 rank Butterworth Active Filters, bandwidth range is 10Hz～5kHz.After filtration module 22 is scaled by signal, output to sampling analysis unit 3.
In conjunction with reference to shown in figure 1 and Fig. 4, sampling analysis unit 3 comprises data sampling module 31 and data analysis module 32.Wherein, data sampling module 31 is for obtaining effective value and the peak value of sampled voltage signal first-harmonic and/or harmonic wave, and obtains real-time waveform data.Data analysis module 32, for obtaining effective value and the peak value of sampled voltage signal according to the effective value of first-harmonic and/or harmonic wave and peak value.Be that data analysis module 32 receives after data sampling module 31 real-time waveform data, carry out FFT conversion and frequency-domain analysis, draw respectively the total effective value of sampled voltage signal (effective value and/or the peak value that comprise sampled voltage signal), and transfer to processor 4 by analyzing the effective value obtaining.Sampling analysis unit 3 can adopt DSP device, also can adopt dedicated devices ADE7880, and ADE7880 device is You San road voltage measurement passage He San road current measurement passage respectively, has PGA and digital filter in passage.The embedded arithmetic unit of ADE7880 device calculates the effective value of effective value, first-harmonic effective value and the each harmonic of signal, and original signal waveform data can be exported.
Processor 4 obtains iron core grounding current value according to the effective value of sampled voltage signal and peak value, relatively earth current and predetermined current threshold value, if earth current surpasses predetermined current threshold value, send alarm command, by alarm module, carry out alarm command, monitor staff investigates fault.When the time that earth current value surpasses predetermined current threshold value is greater than Preset Time (as 24 hours), processor 4 sends suspended market order, and performance element 5 is ended transformers operation, the i.e. inputs of disconnecting transformer.The operation of termination transformer, is not only conducive to staff and fixes a breakdown, and is conducive to transformer Cooling cooling, thereby avoids transformer to damage.
Because transformer temperature is too high, also can cause earth current fluctuation, preferably, when ending transformer operation, processor 4 sends and reruns instruction after Preset Time, and performance element 5 restarts transformer.In the present embodiment, processor 4 can adopt all types of MCU, the processor that the model that also can adopt the YouST company production that cost and power consumption are lower is STM32F103.
As shown in Figure 1, iron core grounding current on-line monitoring equipment also comprises:
Communication unit 6, for the treatment of the communication between device 4 and host computer or CSRC platform.Communication unit 6 makes iron core grounding current on-line monitoring equipment and host computer or CSRC platform carry out communication, so that Long-distance Control, as transmitted data and the configuration data gathering.Communication unit 6 can adopt RS485 communication mode or GPRS communication mode.By communication unit 6, data timing can be uploaded, and can monitor in real time.
Power Management Unit 7, for providing electric energy to each parts of iron core grounding current on-line monitoring equipment, as adopted the power supply input of 220Vac to provide, or is provided by solar cell.
Control unit 8, for the input interface of man-machine interaction is provided, as adopted manipulation keyboard to carry out function selection, or input configuration data.
Display unit 9, for providing the interface of man-machine interaction.Display unit 9 adopts Liquid Crystal Module or the OLED module of graphic dot matrix pattern.The present embodiment adopts OLED display module, and its operating temperature range is wider, and visual angle is wide, clear display.
Memory cell 10, for storing the real-time waveform data of described sampled voltage signal, the effective value of sampled voltage signal and peak value, the first-harmonic of sampled voltage signal and the effective value of harmonic wave and peak value.Memory cell 10 adopts the FLASH memory of 16Mbit.
The transformer overcurrent protection system that the present embodiment provides; processor surpasses predetermined current threshold value in earth current value; and the time that surpasses predetermined current threshold value send suspended market order while being greater than Preset Time; performance element is received the operation of ending transformer after the suspended market order of processor; this is not only conducive to staff and fixes a breakdown; and be conducive to transformer Cooling cooling, thereby avoid transformer to damage.
Be understandable that, above execution mode is only used to principle of the present utility model is described and the illustrative embodiments that adopts, yet the utility model is not limited to this.For those skilled in the art, in the situation that not departing from spirit of the present utility model and essence, can make various modification and improvement, these modification and improvement are also considered as protection range of the present utility model.
Claims (10)
1. a transformer overcurrent protection system, normally moves for the protection of transformer, comprising:
Signal gathering unit, for obtaining the sampled voltage signal corresponding with earth current size;
Processor, for according to described sampled voltage signal acquisition earth current value, and when described earth current value surpasses predetermined current threshold value, sends execution instruction;
Performance element, carries out corresponding operation for the described execution instruction of sending according to described processor;
It is characterized in that, the time that described processor surpasses predetermined current threshold value in described earth current value is sent suspended market order while being greater than Preset Time, and described performance element is ended transformer operation.
2. transformer overcurrent protection system according to claim 1, is characterized in that, described processor is sending operating instruction after Preset Time, described performance element starting transformer.
3. transformer overcurrent protection system according to claim 1, is characterized in that, described processor sends alarm command when described earth current value surpasses described predetermined current threshold value, and described performance element is carried out alarm command.
4. transformer overcurrent protection system according to claim 1, is characterized in that, also comprises:
Signal processing unit, for the treatment of described sampled voltage signal;
Sampling analysis unit, for obtaining effective value and the peak value of described sampled voltage signal first-harmonic and harmonic wave, and obtains effective value and the peak value of described sampled signal.
5. transformer overcurrent protection system according to claim 4, is characterized in that, described signal processing unit comprises:
Control amplification module, for controlling, amplify described sampled voltage signal;
Filtration module, carries out filtering for the described sampled voltage signal to after amplifying.
6. transformer overcurrent protection system according to claim 5, is characterized in that, described sampling analysis unit comprises:
Data sampling module, for obtaining effective value and the peak value of described sampled voltage signal first-harmonic and/or harmonic wave;
Data analysis module, for obtaining effective value and the peak value of described sampled voltage signal according to the effective value of first-harmonic and/or harmonic wave and peak value.
7. transformer overcurrent protection system according to claim 6, is characterized in that, described processor obtains described earth current value according to the effective value of described sampled voltage signal and peak value.
8. transformer overcurrent protection system according to claim 4, is characterized in that, described signal gathering unit comprises:
Band magnetic gap coil, for zero magnetic flux balance with the sampler space is provided;
Magnetic Sensor, is located at the described magnetic gap position with magnetic gap coil, by responding to the magnetic field of magnetic gap position, obtains induced voltage signal;
Differential operational amplifier, for converting described induced voltage signal to single-ended voltage signal;
Electric current and voltage converting unit, for converting described single-ended voltage signal to current signal, and by the described winding with magnetic gap coil of described current signal input;
Pressure resistance, is connected between described winding and ground with magnetic gap coil, in order to obtain resistance voltage signal;
Low noise operational amplifier, its input is connected with described pressure resistance one end away from ground connection, output is connected with described signal processing unit, and described low noise operational amplifier is used for amplifying described resistance voltage signal and obtains sampled voltage signal, and impedance transformation is provided.
9. transformer overcurrent protection system according to claim 8, is characterized in that, described Magnetic Sensor is GMR Magnetic Sensor TMR Magnetic Sensor.
10. transformer overcurrent protection system according to claim 1, is characterized in that, also comprises:
Communication unit, for the communication between described processor and host computer or CSRC platform;
Power Management Unit, for providing electric energy;
Control unit, for the input interface of man-machine interaction is provided;
Display unit, for providing the interface of man-machine interaction;
Memory cell, for storing the real-time waveform data of described sampled voltage signal, the effective value of sampled voltage signal and peak value, the first-harmonic of sampled voltage signal and the effective value of harmonic wave and peak value.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420026389.2U CN203761026U (en) | 2014-01-16 | 2014-01-16 | Transformer overcurrent protection system |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201420026389.2U CN203761026U (en) | 2014-01-16 | 2014-01-16 | Transformer overcurrent protection system |
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| Publication Number | Publication Date |
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| CN203761026U true CN203761026U (en) | 2014-08-06 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN201420026389.2U Expired - Fee Related CN203761026U (en) | 2014-01-16 | 2014-01-16 | Transformer overcurrent protection system |
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104184120A (en) * | 2014-09-11 | 2014-12-03 | 南自晋能自动化有限公司 | High-performance transformer protection device |
| CN105067868A (en) * | 2015-09-15 | 2015-11-18 | 深圳市信瑞达电力设备有限公司 | Current measuring method and device |
| CN107066067A (en) * | 2017-01-25 | 2017-08-18 | 郑州云海信息技术有限公司 | A kind of board Over Current Protection System, method, computer-readable recording medium and storage control |
-
2014
- 2014-01-16 CN CN201420026389.2U patent/CN203761026U/en not_active Expired - Fee Related
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104184120A (en) * | 2014-09-11 | 2014-12-03 | 南自晋能自动化有限公司 | High-performance transformer protection device |
| CN105067868A (en) * | 2015-09-15 | 2015-11-18 | 深圳市信瑞达电力设备有限公司 | Current measuring method and device |
| CN105067868B (en) * | 2015-09-15 | 2018-06-26 | 深圳市信瑞达电力设备有限公司 | current measuring method and device |
| CN107066067A (en) * | 2017-01-25 | 2017-08-18 | 郑州云海信息技术有限公司 | A kind of board Over Current Protection System, method, computer-readable recording medium and storage control |
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Legal Events
| Date | Code | Title | Description |
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| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20140806 Termination date: 20200116 |
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| CF01 | Termination of patent right due to non-payment of annual fee |