CN206863089U - Threephase current transformer no-load voltage ratio on-line conversion intelligent controller - Google Patents

Abstract

It the utility model is related to composite transformation ratio current transformer ratio conversion control device in three-phase electric energy metering device, specially threephase current transformer no-load voltage ratio on-line conversion intelligent controller.Solve the problems, such as that electric energy metrical field lacks threephase current transformer no-load voltage ratio on-line conversion intelligent controlling device at present.The utility model secondary to composite transformation ratio current transformer ratio can carry out online switching and with second open circuit safeguard measure is prevented, that is, moment make-before-break when changing composite transformation ratio current transformer ratio, can effectively avoid device damage and personal injury accident；The utility model sampling electric power meter voltage transformer summation current transformer signal carries out contrast calculation process, can intelligent decision direction of tide whether change and whether size of current exceeds setting value, the no-load voltage ratio of the program automatic conversion composite transformation ratio current transformer of setting can be passed through, realize that live signal identifies, intelligent decision controls, no-load voltage ratio is changed safely, generates electricity and electricity consumption is two-way all measures.

Description

Threephase current transformer no-load voltage ratio on-line conversion intelligent controller

Technical field

Composite transformation ratio current transformer ratio conversion control device in three-phase electric energy metering device is the utility model is related to, is had Body is threephase current transformer no-load voltage ratio on-line conversion intelligent controller.

Background technology

Electric power meter circuit is only sent out for rated load at present（With）Electricity designs a kind of monotropic ratio or twice pair The current transformer of no-load voltage ratio, the disposable only selection in scene install a kind of transformation ratio current transformer, forbid to change no-load voltage ratio after being powered Because second open circuit has very big danger to power network.Replacing current transformer ratio is needed to power off, artificial secondary short circuit is jumped Line replacing no-load voltage ratio is abnormally dangerous, and safety does not allow.Electric energy metrical Current Transformer all uses S levels, is typically designed operation In the range of the 20%~120% of its no-load voltage ratio rated current, by People's Republic of China's measurement verification regulations《JJG313-2010 Verification of Measuring Current Transformer》With《JJG1021-2007 electric power mutual-inductors》, the error limit of this scope S level current transformers Linear steady, when beyond 20%~120% scope, current transformer error becomes big.Sometimes electric current exceeds several times to hundred Times, such as wind（Water）The generating and electricity consumption of electricity or heat supply heating phase and non-heating period or the enterprise's seasonality electricity consumption periodically to go into operation Load variations are very big, between usual no-load voltage ratio needs 5 times to 100 times of change, the measurable scope of remote supercurrent transformer, cause Leakage metering and energy waste in underload or excess load.Two sets of metering systems of increase need to increase land used space and metering Equipment, trouble point and O＆M cost are also increased, and do not meet existing national standards code.

The electric administrative department also having now has used Composite Double transformation ratio current transformer or variable specific current transformer, multiple Transformation ratio current transformer is closed when changing no-load voltage ratio, it is necessary to have a power failure, a series of manual operation such as rewiring, gives Electricity customers band Carry out inconvenient and economic loss, while need substantial amounts of time and manpower.It is therefore desirable to equip a kind of threephase current transformer to become Than on-line conversion intelligent controller.

The content of the invention

The utility model solves electric energy metrical field and lacks threephase current transformer no-load voltage ratio on-line conversion intelligent control at present The problem of device, there is provided a kind of threephase current transformer no-load voltage ratio on-line conversion intelligent controller, the supporting electric energy metrical of the controller The composite transformation ratio current transformer of field power load change greatly uses.

The utility model adopts the following technical scheme that realization：Threephase current transformer no-load voltage ratio on-line conversion intelligent control Instrument, including the sampled voltage transformer for cascading and connecing with the threephase potential transformer in electric power meter, sampled voltage mutual inductance Device amplifies the voltage signal U of sampling by the first programmable amplifier, then passes to AD moduluses by the first filter filtering and turn Parallel operation；Also include respectively with A, C the phase composite transformation ratio current transformer or A, B, C phase composite transformation ratio in electric power meter The current signal of every phase sampler is passed through sampling by the sampling current transformer of current transformer cascade concatenation, sampling current transformer Resistance is converted into voltage signal Ui, and voltage signal Ui passes to by the amplification of the second programmable amplifier and the second filter filtering again AD analog-digital converters, voltage signal Ui are given to MCU microprocessors by synchronizer simultaneously, and AD analog-digital converters will pass through simultaneously to be put The voltage signal U and Ui filtered greatly is also passed to MCU microprocessors by data/address bus, and touch LCD screen believes the instruction of user Number issue MCU microprocessors；First output end of MCU microprocessors is connected with A, C phase normally opened contact relay parallel with one another J2, J4 or A, B, C phase normally opened contact relay J2, J6, J4, the second output end of MCU microprocessors are connected with parallel with one another A, C phase normally-closed contact relay J1, J3 or A, B, C phase normally-closed contact relay J1, J5, J3；A, C phases normally opened contact relay The small no-load voltage ratio that device J2, J4 normally opened contact are serially connected with A, C phase composite transformation ratio current transformer in electric power meter respectively is defeated Leading-out terminal, A, C phase that A, C phase normally-closed contact relay J1, J3 normally-closed contact are serially connected with electric power meter respectively are compound The large velocity ratio output line terminal of transformation ratio current transformer；Or A, B, C phase normally opened contact relay J2, J6, J4 normally opened contact point The small no-load voltage ratio output line terminal for A, B, C the phase composite transformation ratio current transformer not being serially connected with electric power meter, A, B, C phase are normally closed Contact relay J1, J5, J3 normally-closed contact are serially connected with A, B, C phase composite transformation ratio Current Mutual Inductance in electric power meter respectively The large velocity ratio output line terminal of device.

The sine wave for the voltage signal Ui that MCU microprocessors transfer according to synchronized device becomes square wave and gives MCU microprocessors As time reference, make voltage signal U and Ui synchronized sampling on a time point；MCU microprocessors compare to be turned through AD moduluses The phase that the voltage signal U and Ui that parallel operation transfers are put at the same time, to determine the phase difference between voltage and current, in addition Current amplitude is determined by Ui and sampling resistor；

Through touch LCD screen to MCU microprocessor input current upper limit set values and lower current limit setting value, when according to electricity When the current amplitude that pressure signal Ui is determined is less than lower current limit setting value, MCU microprocessors make A, C phase normally opened contact relay J2, J4 or A, B, C phase normally opened contact relay J2, J6, J4 obtain electric, corresponding normally opened contact closure, make A, C phase normally-closed contact Relay J1, J3 or A, B, C phase normally-closed contact relay J1, J5, J3 are delayed electric, and corresponding normally-closed contact delay disconnects, from And the on-line conversion size no-load voltage ratio of current transformer under the safe condition of no second open circuit；When true according to voltage signal Ui When fixed current amplitude is more than upper current limit setting value, MCU microprocessors make A, C phase normally-closed contact relay J1, J3 or A, B, C Phase normally-closed contact relay J1, J5, J3 dead electricity, corresponding normally-closed contact closure, make A, C phase normally opened contact relay J2, J4 or Person's A, B, C phase normally opened contact relay J2, J6, J4 delay dead electricity, corresponding normally opened contact delay disconnects, so as to not secondary The on-line conversion small large velocity ratio of current transformer under the safe condition of open circuit；

Or during for bidirectional measuring, when the phase difference between electric current and voltage is equal to 180o ± 10o, MCU microprocessors It is electric that device obtains A, C phase normally opened contact relay J2, J4 or A, B, C phase normally opened contact relay J2, J6, J4, corresponding normally opened Contact closure, A, C phase normally-closed contact relay J1, J3 or A, B, C phase normally-closed contact relay J1, J5, J3 is set to be delayed electric, it is right The normally-closed contact delay answered disconnects, so as to the on-line conversion size of current transformer under the safe condition of no second open circuit No-load voltage ratio；When the phase difference between electric current and voltage is equal to 0o ± 10o, MCU microprocessors make A, C phase normally-closed contact relay J1, J3 or A, B, C phase normally-closed contact relay J1, J5, J3 dead electricity, corresponding normally-closed contact closure, make A, C phase normally opened contact after Electrical equipment J2, J4 or A, B, C phase normally opened contact relay J2, J6, J4 delay dead electricity, corresponding normally opened contact delay disconnect, from And the on-line conversion small large velocity ratio of current transformer under the safe condition of no second open circuit.

The effect of synchronizer is that voltage signal Ui sine wave is become square wave to MCU microprocessors as time reference, Make voltage signal Ui with voltage signal U synchronized samplings on a time point, accurately to determine the phase between electric current and voltage Difference.

The utility model can it is secondary to composite transformation ratio current transformer ratio progress online switch and with prevent it is secondary Open-circuit-protection measure, that is, change composite transformation ratio current transformer ratio when moment make-before-break, can effectively avoid device damage and Personal injury accident；The utility model sampling electric power meter voltage transformer summation current transformer signal carries out contrast computing Processing, can intelligent decision direction of tide whether change and whether size of current exceeds setting value, the journey of setting can be passed through The no-load voltage ratio of sequence automatic conversion composite transformation ratio current transformer, realize that live signal identifies, intelligent decision control, no-load voltage ratio turns safely Change, generate electricity and electricity consumption is two-way all measures.

Brief description of the drawings

Fig. 1 is that circuit theory diagrams of the present utility model and the connection principle for three-phase-three-wire energy measurement device are illustrated Figure；

Fig. 2 is that circuit theory diagrams of the present utility model and the connection principle for three-phase and four-line electric power meter are illustrated Figure.

In figure：1 is metering intelligent electric meter, and dotted line frame 2 is controller described in the utility model.

Embodiment

Embodiment 1

This example is as shown in figure 1, be applied to three-phase-three-wire energy measurement device.

Threephase current transformer no-load voltage ratio on-line conversion intelligent controller, including it is mutual with the three-phase voltage in electric power meter The sampled voltage transformer 3 that sensor 6 is cascaded and connect, sampled voltage transformer 3 program control put the voltage signal U of sampling by first Big device 22 amplifies, then passes to AD analog-digital converters 15 by the filtering of the first wave filter 24；Also include filling with electric energy metrical respectively The sampling current transformer 4 of the cascade concatenation of A, C phase composite transformation ratio current transformer 7,8 in putting, sampling current transformer 4 will be every The current signal of phase sampler is converted into voltage signal Ui by sampling resistor 5, and voltage signal Ui passes through the second programmable amplifier again 12 amplifications and the filtering of the second wave filter 14 pass to AD analog-digital converters 15, and voltage signal Ui is given to by synchronizer 13 simultaneously MCU microprocessors 18, AD analog-digital converters 15 will also be passed by the voltage signal U and Ui for amplifying filtering by data/address bus simultaneously MCU microprocessors 18 are passed, the command signal of user is issued MCU microprocessors 18 by touch LCD screen 16；MCU microprocessors 18 The first output end be connected with A, C phase normally opened contact relay J2, J4 parallel with one another, the second output of MCU microprocessors 18 End is connected with A, C phase normally-closed contact relay J1, J3 parallel with one another；A, C phases normally opened contact relay J2, J4 normally opened contact 10 are serially connected with the small no-load voltage ratio output line terminal of A, C phase composite transformation ratio current transformer 7,8 in electric power meter, A, C phase respectively A, C phase composite transformation ratio electric current that normally-closed contact relay J1, J3 normally-closed contact 11 are serially connected with electric power meter respectively are mutual The large velocity ratio output line terminal of sensor 7,8；

The sine wave for the voltage signal Ui that MCU microprocessors 18 transfer according to synchronized device 13 becomes square wave and gives MCU micro- places Device is managed as time reference, makes voltage signal U and Ui synchronized sampling on a time point；MCU microprocessors 18 compare through AD The phase that the voltage signal U and Ui that analog-digital converter 15 transfers are put at the same time, to determine the phase between voltage and current Potential difference, current amplitude is determined additionally by Ui and sampling resistor 5；

Through touch LCD screen 16 to the input current upper limit set value of MCU microprocessors 18 and lower current limit setting value, work as root According to voltage signal Ui determine current amplitude be less than lower current limit setting value when, MCU microprocessors 18 make A, C phase normally opened contact after Electrical equipment J2, J4 obtain electric, and corresponding normally opened contact 10 closes, and A, C phase normally-closed contact relay J1, J3 is delayed electric, corresponding The delay of normally-closed contact 11 disconnects, and becomes so as to the size of the on-line conversion current transformer under the safe condition of no second open circuit Than；When the current amplitude determined according to voltage signal Ui is more than upper current limit setting value, MCU microprocessors 18 make A, C phase normal Closed contact relay J1, J3 dead electricity, corresponding normally-closed contact 11 close, and lose A, C phase normally opened contact relay J2, J4 delay Electricity, the delay of corresponding normally opened contact 10 disconnect, so as to the on-line conversion Current Mutual Inductance under the safe condition of no second open circuit The small large velocity ratio of device；

Or during for bidirectional measuring, when the phase difference between electric current and voltage is equal to 180o ± 10o, MCU microprocessors It is electric that device 18 obtains A, C phase normally opened contact relay J2, J4, and corresponding normally opened contact 10 closes, and makes A, C phase normally-closed contact relay J1, J3 are delayed electric, and the corresponding delay of normally-closed contact 11 disconnects, so as to the on-line conversion under the safe condition of no second open circuit The size no-load voltage ratio of current transformer；When the phase difference between electric current and voltage is equal to 0o ± 10o, MCU microprocessors 18 make A, C phases normally-closed contact relay J1, J3 dead electricity, corresponding normally-closed contact 11 close, and make A, C phase normally opened contact relay J2, J4 Be delayed dead electricity, the delay of corresponding normally opened contact 10 disconnects, so as to the on-line conversion electricity under the safe condition of no second open circuit The small large velocity ratio of current transformer.

When it is implemented, upper current limit setting value and lower current limit setting value can be according to A, C phase composite transformation ratio Current Mutual Inductances The difference of device 7,8 and the different set that is needed；Usual lower limit set value selects the 20% of secondary rated current, upper limit setting Value selects the 120% of secondary rated current.Sampling resistor 5 is from 100 Ω's.Sampling current transformer 4 selects 0VA no-load voltage ratios 5A/20mA（Or 1A/20mA）.Sampled voltage transformer 3 is from 0VA no-load voltage ratios 100V/2V.Delay time is set to 1~2 Second.

Embodiment 2

This example is as shown in Fig. 2 be applied to three-phase and four-line electric power meter.

Threephase current transformer no-load voltage ratio on-line conversion intelligent controller, including it is mutual with the three-phase voltage in electric power meter The sampled voltage transformer 3 that sensor 19 is cascaded and connect, sampled voltage transformer 3 are program control by first by the voltage signal U of sampling Amplifier 22 amplifies, then passes to AD analog-digital converters 15 by the filtering of the first wave filter 24；Also include respectively with electric energy metrical The sampling current transformer 4 of the cascade concatenation of A, B, C phase composite transformation ratio current transformer 7,20,8 in device, sample rate current mutual inductance The current signal of every phase sampler is converted into voltage signal Ui by device 4 by sampling resistor 5, and voltage signal Ui is program control by second again Amplifier 12 amplifies and the filtering of the second wave filter 14 passes to AD analog-digital converters 15, and voltage signal Ui passes through synchronizer 13 simultaneously MCU microprocessors 18 are given to, AD analog-digital converters 15 will pass through data/address bus by the voltage signal U and Ui that amplify filtering simultaneously MCU microprocessors 18 are also passed to, the command signal of user is issued MCU microprocessors 18 by touch LCD screen 16；MCU microprocessors First output end of device 18 is connected with A, B, C phase normally opened contact relay J2, J6, J4 parallel with one another, MCU microprocessors 18 Second output end is connected with A, B, C phase normally-closed contact relay J1, J5, J3 parallel with one another；A, B, C phase normally opened contact relay J2, J6, J4 normally opened contact 10 are serially connected with A, B, C phase composite transformation ratio current transformer 7,20,8 in electric power meter respectively Small no-load voltage ratio output line terminal, A, B, C phase normally-closed contact relay J1, J5, J3 normally-closed contact 11 is serially connected with electric energy metrical respectively The large velocity ratio output line terminal of A, B, C phase composite transformation ratio current transformer 7,20,8 in device；

The sine wave for the voltage signal Ui that MCU microprocessors 18 transfer according to synchronized device 13 becomes square wave and gives MCU micro- places Device is managed as time reference, makes voltage signal U and Ui synchronized sampling on a time point；MCU microprocessors 18 compare through AD The phase that the voltage signal U and Ui that analog-digital converter 15 transfers are put at the same time, to determine the phase between voltage and current Potential difference, current amplitude is determined additionally by Ui and sampling resistor 5；

Through touch LCD screen 16 to the input current upper limit set value of MCU microprocessors 18 and lower current limit setting value, work as root When being less than lower current limit setting value according to the voltage signal Ui current amplitudes determined, MCU microprocessors 18 make A, B, C phase normally opened contact Relay J2, J6, J4 obtain electric, and corresponding normally opened contact 10 closes, and A, B, C phase normally-closed contact relay J1, J5, J3 is delayed Electricity, the delay of corresponding normally-closed contact 11 disconnect, so as to the on-line conversion Current Mutual Inductance under the safe condition of no second open circuit The size no-load voltage ratio of device；When the current amplitude determined according to voltage signal Ui is more than upper current limit setting value, MCU microprocessors 18 Make A, B, C phase normally-closed contact relay J1, J5, J3 dead electricity, corresponding normally-closed contact 11 closes, make A, B, C phase normally opened contact after Electrical equipment J2, J6, J4 delay dead electricity, the corresponding delay of normally opened contact 10 disconnects, so as under the safe condition of no second open circuit The on-line conversion small large velocity ratio of current transformer；

Or during for bidirectional measuring, when the phase difference between electric current and voltage is equal to 180o ± 10o, MCU microprocessors It is electric that device 18 obtains A, B, C phase normally opened contact relay J2, J6, J4, and corresponding normally opened contact 10 closes, and makes A, B, C phase are normally closed to touch Point relay J1, J5, J3 are delayed electric, and the corresponding delay of normally-closed contact 11 disconnects, so as in the safe shape of no second open circuit The on-line conversion size no-load voltage ratio of current transformer under state；When the phase difference between electric current and voltage is equal to 0o ± 10o, MCU Microprocessor 18 makes A, B, C phase normally-closed contact relay J1, J5, J3 dead electricity, and corresponding normally-closed contact 11 closes, and makes A, B, C phase Normally opened contact relay J2, J6, J4 delay dead electricity, the corresponding delay of normally opened contact 10 disconnects, so as in no second open circuit The on-line conversion small large velocity ratio of current transformer under safe condition.

When it is implemented, upper current limit setting value and lower current limit setting value can be mutual according to A, B, C phase composite transformation ratio electric current The difference of sensor 7,20,8 and the different set that is needed；Usual lower limit set value selects the 20% of secondary rated current, the upper limit Setting value selects the 120% of secondary rated current.Sampling resistor 5 is from 100 Ω's.Sampling current transformer 4 is become from 0VA Compare 5A/20mA（Or 1A/20mA）.Sampled voltage transformer 3 is from 0VA no-load voltage ratios 100V/2V.Delay time is set to 1 ~2 seconds.

Claims (2)

1. A kind of 1. threephase current transformer no-load voltage ratio on-line conversion intelligent controller, it is characterised in that including with electric power meter The threephase potential transformer sampled voltage transformer that cascades and connect（3）, sampled voltage transformer（3）By the voltage signal of sampling U passes through the first programmable amplifier（22）Amplification, then by the first wave filter（24）Filtering passes to AD analog-digital converters（15）；Also Including respectively with A, C phase composite transformation ratio current transformer in electric power meter（7、8）Cascade the sample rate current mutual inductance of concatenation Device（4）, sampling current transformer（4）The current signal of every phase sampler is passed through into sampling resistor（5）Voltage signal Ui is converted into, electricity Pressure signal Ui passes through the second programmable amplifier again（12）Amplification and the second wave filter（14）Filtering passes to AD analog-digital converters （15）, voltage signal Ui passes through synchronizer simultaneously（13）It is given to MCU microprocessors（18）, AD analog-digital converters（15）Simultaneously will be through The voltage signal U and Ui for crossing amplification filtering is also passed to MCU microprocessors by data/address bus（18）, touch LCD screen（16） The command signal of user issues MCU microprocessors（18）；MCU microprocessors（18）The first output end be connected with it is parallel with one another A, C phases normally opened contact relay J2, J4, MCU microprocessor（18）The second output end to be connected with A, C phase parallel with one another normally closed Contact relay J1, J3；A, C phases normally opened contact relay J2, J4 normally opened contact（10）Electric power meter is serially connected with respectively In A, C phase composite transformation ratio current transformer（7、8）Small no-load voltage ratio output line terminal, A, C phase normally-closed contact relay J1, J3's is normal Closed contact（11）A, C the phase composite transformation ratio current transformer being serially connected with respectively in electric power meter（7、8）Large velocity ratio output Line end.
2. A kind of 2. threephase current transformer no-load voltage ratio on-line conversion intelligent controller, it is characterised in that including with electric power meter The threephase potential transformer sampled voltage transformer that cascades and connect（3）, sampled voltage transformer（3）By the voltage signal of sampling U passes through the first programmable amplifier（22）Amplification, then by the first wave filter（24）Filtering passes to AD analog-digital converters（15）；Also Including respectively with A, B, C phase composite transformation ratio current transformer in electric power meter（7、20、8）Cascade the sample rate current of concatenation Transformer（4）, sampling current transformer（4）The current signal of every phase sampler is passed through into sampling resistor（5）It is converted into voltage signal Ui, voltage signal Ui pass through the second programmable amplifier again（12）Amplification and the second wave filter（14）Filtering passes to AD analog-to-digital conversions Device（15）, voltage signal Ui passes through synchronizer simultaneously（13）It is given to MCU microprocessors（18）, AD analog-digital converters（15）Simultaneously will Voltage signal U and Ui by amplification filtering is also passed to MCU microprocessors by data/address bus（18）, touch LCD screen（16） The command signal of user is issued MCU microprocessors（18）；MCU microprocessors（18）The first output end be connected with it is parallel with one another A, B, C phase normally opened contact relay J2, J6, J4, MCU microprocessors（18）The second output end be connected with A parallel with one another, B, C phases normally-closed contact relay J1, J5, J3；A, B, C phase normally opened contact relay J2, J6, J4 normally opened contact（10）Go here and there respectively A, B, C the phase composite transformation ratio current transformer being connected in electric power meter（7、20、8）Small no-load voltage ratio output line terminal, A, B, C phase Normally-closed contact relay J1, J5, J3 normally-closed contact（11）A, B, C the phase composite transformation ratio being serially connected with respectively in electric power meter Current transformer（7、20、8）Large velocity ratio output line terminal.