CN104181417B - A kind of transient-wave circuit of electronic current mutual inductor big electric current synthesis - Google Patents

Abstract

The invention provides the transient-wave circuit of a kind of electronic current mutual inductor big electric current synthesis, including controller unit, DC charging power supply and waveform output unit；Waveform output unit is connected with ECT test product；Controller unit includes charge control module, control of discharge module, waveform monitoring modular and transient-wave adjustment module；Controller unit is for controlling the duty of electronic device in waveform output unit, thus controls waveform output unit to ECT test product output transient voltage waveform and transient current waveform.Compared with prior art, the transient-wave circuit of a kind of electronic current mutual inductor big electric current synthesis that the present invention provides, the transient voltage waveform of output and the current peak of transient current waveform, damping time constant accurately can be adjusted, to meet the testing requirement of different model electronic current mutual inductor test product.

Description

A kind of transient-wave circuit of electronic current mutual inductor big electric current synthesis

Technical field

The present invention relates to a kind of transient-wave combiner circuit, be specifically related to a kind of electronic current mutual inductor big electric current synthesis Transient-wave circuit.

Background technology

The relay protection of electronic current mutual inductor includes direct method and waits ampere-turn method.Direct method by a Large Copacity and The current source possessing phase selection function is tested, and process of the test needs to meet primary circuit and wants time constant simultaneously Ask.But the most do not possess at present and carry out long current transformer big current temporary state test facilities；As when rated current being 2kA, can not carry out relay protection to it when symmetrical short-circuit electric current is 40kA, observe the most in a large number through the present inventor, study discovery There is no the prior art of the transient error test requirements document that can meet extra-high voltage grid current transformer at present.

During electronic current mutual inductor relay protection due to primary current too greatly, in product export inspection, test chamber Inspection under inspection and on-the-spot handing-over environment is difficult to directly produce a stable rating test electric current.Therefore Primary Conductor is used All around the method waiting ampere-turn, with flexible circuit conductor at test product coil along the circumferential direction uniform coiling number circle coil, as an inferior ampere-turn Coil, makes single turn smaller current by waiting ampere-turn can produce the biggest electric current of equivalence as experiment power supply.Fit Deng ampere-turn method For delivery test, Large Copacity GIS supporting current mutual inductor on site commissioning test and the on-the-spot school of GTA that great current mutual inductor is raw Test, but, carry out in current transformer error process of the test in ampere-turn methods such as employings, the measurement of its measurement error and direct method is by mistake There is deviation in difference.

Analyzing direct method and wait ampere-turn method to understand, its experiment abberation is all owing to measuring level and measuring the current transformer of level Cause；The close value of iron core magnetic of metering level and measurement level current transformer is higher than protected level current transformer, and core section Long-pending the least.When electronic current mutual inductor actual motion, one time bus is placed in current transformer center, primary current The magnetic field produced is in core interior distribution uniform, and error performance meets design requirement.Equivalence is carried out by mistake in ampere-turn methods such as employings During difference test, although multiturn wire equal distribution on winding circumference, its magnetic field piecewise uniform on the whole produced, but Magnetic field near every circle coil plane is the strongest, causes that the magnetic of the iron core local of its correspondence is close to be increased, and local magnetic saturation even occurs, Iron loss increases, and one time exciting current strengthens, and ultimately causes current transformer error and occurs deviation the most accordingly.Therefore by suitably increasing Add current transformer core section, reduce the corrective measure improvement such as the close value of magnetic, increase shield winding, wire arrangements of optimization Direct method and the inequivalence problem of ampere-turn method such as grade.

Electronic current mutual inductor synthetic test, in addition to the ampere-turn methods such as employing realize a High-current output, also to enter Row stable state power current and the synthesis of direct current transient current, to export the fault current that conformance with standard requires.Accordingly, it is desirable to provide A kind of the important parameters such as the transient current peak value of electronic current mutual inductor, damping time constant accurately can be adjusted, The Waveform generating circuit of electronic current mutual inductor synthetic test transient requirements is met with output.

Summary of the invention

In order to meet the needs of prior art, the invention provides the temporary of a kind of electronic current mutual inductor big electric current synthesis State waveform circuit, described circuit includes that controller unit, described circuit include DC charging power supply and be connected with ECT test product Waveform output unit；

Described controller unit includes that charge control module, control of discharge module, waveform monitoring modular and transient-wave are adjusted Joint module；The electronic device output in described waveform output unit of described controller unit adjusts the signal of duty to control Waveform output unit is to described ECT test product output transient voltage waveform and transient current waveform.

Preferably, described waveform output unit includes the charging crystalline substance lock being connected to the positive terminal of described DC charging power supply Pipe, commutator, electric discharge IGCT, adjustable resistance and controllable impedance；Low sense diverter and the negative pole of described DC charging power supply End connects；

Preferably, fly-wheel diode is connected in reverse parallel in described DC charging power supply two ends；One end of described fly-wheel diode Being connected between described electric discharge IGCT and adjustable resistance, the other end is connected to the negative pole end of described DC charging power supply and low sense Between diverter；

Preferably, the number of described charging IGCT, commutator and electric discharge IGCT is 2；One described charging crystalline substance The series arm of brake tube, commutator and electric discharge IGCT is connected to the positive terminal of described DC charging power supply and described adjustable electric Between resistance；The series arm of another described charging IGCT, commutator and electric discharge IGCT is also connected to described direct current and fills Between positive terminal and the described adjustable resistance of electricity power supply；

Preferably, described commutator is connected and the negative pole end of described DC charging power supply and low by storage capacitor respectively Between sense diverter；

When described charging IGCT is connected with described storage capacitor by described commutator, described DC charging electricity Source, charging IGCT and storage capacitor composition charge current loop, be charged described storage capacitor；

When described electric discharge IGCT is connected with described storage capacitor by described commutator, described electric discharge IGCT, Storage capacitor and described fly-wheel diode composition discharge current loop, described storage capacitor discharges；

Preferably, described fly-wheel diode is forward conduction when the voltage zero-cross polarity inversion of transient voltage waveform, thus The resonance when voltage over zero is stopped, and discharge current is exponentially decayed, and meets the output requirement of transient voltage waveform；

Preferably, described charge control module, it is used for controlling described commutator feed motion and makes described charging current Storage capacitor is charged by loop；

Described control of discharge module, is used for controlling described commutator feed motion and described storage capacitor is put Electricity；

Described waveform monitoring modular, gathers the electric current of the low sense diverter of waveform output unit, thus monitors described transient state Voltage waveform and described transient current waveform；

Described transient-wave adjustment module, for regulating adjustable resistance and the controllable impedance of waveform output unit, thus right Described transient voltage waveform and described transient current waveform are adjusted.

Compared with immediate prior art, the excellent effect of the present invention is:

1, in technical solution of the present invention, DC charging power supply is used to charge to storage capacitor, by controlling DC source Size, thus control the size of the transient current of waveform output unit output；

2, in technical solution of the present invention, at one fly-wheel diode of two ends reverse parallel connection of DC charging power supply so that During voltage zero-cross polarity inversion in transient voltage waveform, this fly-wheel diode of forward conduction, resonance stops at voltage over zero, Thus transient current waveform and the equal Pass Test requirement of transient voltage waveform；

3, in technical solution of the present invention, employing commutator control charging IGCT leads on-off with electric discharge IGCT Open, thus the synthesis realizing transient current waveform and transient voltage waveform controls；

4, in technical solution of the present invention, it is respectively adopted two discharge and recharge IGCTs, it is possible to realize electronic current mutual inductor The reclosing of big electric current synthetic test controls；

5, in technical solution of the present invention, use adjustable resistance and controllable impedance to transient current waveform and transient voltage waveform Accurately adjust.

Accompanying drawing explanation

The present invention is further described below in conjunction with the accompanying drawings.

Fig. 1 is: the transient-wave circuit theory of a kind of electronic current mutual inductor big electric current synthesis in the embodiment of the present invention Figure；

Fig. 2 is: the fundamental diagram of sustained diode 5 in Fig. 1；

Fig. 3 is: the harmonic wave figure of energy-storage capacitor electric discharge during sustained diode 5 locking in Fig. 1；

Fig. 4 is: the partial enlarged drawing of harmonic wave figure shown in Fig. 3；

Fig. 5 is: the harmonic wave figure of energy-storage capacitor electric discharge when sustained diode 5 turns in Fig. 1.

Detailed description of the invention

Embodiments of the invention are described below in detail, and the example of described embodiment is shown in the drawings, the most from start to finish Same or similar label represents same or similar element or has the element of same or like function.Below with reference to attached The embodiment that figure describes is exemplary, it is intended to is used for explaining the present invention, and is not considered as limiting the invention.

The transient-wave being applicable to electronic current mutual inductor big electric current synthetic test provided in the present embodiment produces electricity Road principle is as it is shown in figure 1, described circuit includes controller unit, DC charging power supply and waveform output unit；

1, waveform output unit is connected between DC charging power supply and ECT test product as shown in the figure, including: charging IGCT D1 and D2, discharge IGCT D3 and D4, sustained diode 5, and commutator K1 and K2, storage capacitor C1 and C2 adjustable resistance can Adjust inductance and low sense diverter；

Charging IGCT D1, commutator K1, electric discharge IGCT D3, adjustable resistance and controllable impedance are sequentially connected to direct current Between positive terminal and the ECT test product of charge power supply；Charging IGCT D2, commutator K2, electric discharge IGCT D4, adjustable resistance and Controllable impedance is sequentially connected between the positive terminal of DC charging power supply and ECT test product equally；

Sustained diode 5 is connected in reverse parallel in DC charging power supply two ends, the backward end of sustained diode 5 respectively with electric discharge The backward end of IGCT connects, and the forward end of sustained diode 5 is connected with the negative pole end of DC charging power supply；

Commutator K1 and K2 respectively by storage capacitor C1 and C2 be connected to DC charging power supply and low sense diverter it Between.

2, waveform output unit includes charge current loop and discharge current loop, particularly as follows:

When commutator K1 is connected with charging IGCT D1, and commutator K2 is connected with charging IGCT D2, now direct current Charge power supply, charging IGCT, commutator and storage capacitor composition charge current loop, be charged storage capacitor；

When commutator K1 is connected with electric discharge IGCT D3, and commutator K2 is connected with electric discharge IGCT D4, now discharges IGCT, commutator, storage capacitor and fly-wheel diode composition charge current loop, storage capacitor discharges；

Fig. 2 shows the sustained diode 5 operation principle in discharge current loop, the wherein work of sustained diode 5 With including:

(1), when waveform output unit is discharge current loop state, afterflow in circuit, the electronics in protection circuit Device.

(2), when waveform output unit is discharge current loop state, sustained diode 5 is at the electricity of transient voltage waveform Forward conduction when pressing through zero polarity inversion, so that resonance stops when voltage over zero, discharge current is exponentially decayed, full The output requirement of foot transient voltage waveform；

1., in Fig. 2, commutator K includes that commutator K1 and K2, storage capacitor C include storage capacitor C1 and C2；When double When throw switch K is connected with electric discharge IGCT, storage capacitor, adjustable resistance R1, controllable impedance L constitute typical RLC second-order circuit, Owing to adjustable resistance is Milliohm resistance, therefore this RLC second-order circuit is underdamping second-order circuit；Fig. 3 shows storage capacitor Discharging to adjustable resistance and controllable impedance, the transient voltage waveform of waveform output unit output and transient current waveform, due to RLC Second-order circuit is underdamping second-order circuit, so above-mentioned two waveform is the most progressively decayed；

2., the transient voltage waveform shown in Fig. 3 and transient current waveform do not meet the present embodiment test waveform output want Ask, the oscillating waveform time length after first peak value of its transient voltage waveform and transient current waveform, poor stability；In reality In electronic current mutual inductor big electric current synthetic test, set first according to the electronic current mutual inductor of different electric pressures Waveform time length after the size of peak value and first peak value.The voltage zero-cross of transient voltage waveform is may determine that by Fig. 4 During point, the resonance current of transient current waveform reaches maximum, if now allowing resonance stop, discharge current will be with time certain Between constant exponentially decay, then transient current waveform meets test requirements document；

When the voltage zero-cross polarity inversion of transient voltage waveform, forward conduction sustained diode 5, storage capacitor is short Road, destroys condition of resonance, makes resonance stop at voltage over zero, and now RLC second-order circuit is changed into RL firstorder circuit, such as Fig. 5 Shown in, transient current waveform after electric current reaches maximum according to RL firstorder circuit zero input response decay, this transient current The i.e. Pass Test requirement of waveform；

Wherein, resonance current refers to the discharge current of storage capacitor release；

(3): controller unit is for controlling the duty of electronic device in waveform output unit, thus it is defeated to control waveform Go out unit to ECT test product output transient voltage waveform and transient current waveform；As it is shown in figure 1, include charge control module, electric discharge Control module, waveform monitoring modular and transient-wave adjustment module, particularly as follows:

1.: charge control module controls commutator K1 and K2 action simultaneously, and commutator K1 and charging IGCT D1 is even Connecing, commutator K2 is connected with D2 with charging IGCT, and storage capacitor C1 and C2 is charged by DC charging power supply respectively；Fill Electric control module carries out Real-time Collection by collection plate to charging voltage and charging current and is sent to host computer, and host computer will fill Piezoelectric voltage compares with voltage setting value, charging current is compared with current setting value, if described charging voltage and filling Electricity electric current meets the requirement of setting value, then host computer controls to send electric discharge instruction to control of discharge module；Control of discharge module control Commutator processed carries out reclosing, including:

After a, commutator K1 are connected with electric discharge IGCT D3, commutator K2 is connected with electric discharge IGCT D4 again；

After b, commutator K2 are connected with electric discharge IGCT D4, commutator K1 is connected with electric discharge IGCT D3 again.

When control of discharge module detection discharge voltage is close to zero point, forward conduction sustained diode 5, storage capacitor is short Road, so that resonance potential stops near zero-crossing point.

2.: waveform monitoring modular, the voltage and current of the low sense diverter of waveform output unit is gathered by DSP circuit, And be sent to host computer, thus monitor transient voltage waveform and transient current waveform；If waveform output unit generation overvoltage or Overcurrent, then stop electronic current mutual inductor big electric current synthetic test transient-wave and produce circuit work；

3.: transient-wave adjustment module, for regulating adjustable resistance and the controllable impedance of waveform output unit, thus to temporarily State voltage waveform and transient current waveform are adjusted；The voltage signal of operator's foundation host computer collection and current signal, Send parameter adjustment instruction to transient-wave adjustment module, thus regulate the resistance value of adjustable resistance and the inductance of controllable impedance Value, changes circuit parameter at a distance, and the peak value of control transient current and damping time constant are to meet test requirements document.

The zero input response parameter calculation formula of RLC underdamping second-order circuit as shown in Figure 2 is:

1.: transient current computing formula is: $i=\frac{U_c}{\mathrm{\ωL}}{e}^{-\mathrm{\δt}}\sin \left(\mathrm{\ωt}\right);$

Wherein, U_cFor charging voltage, $\mathrm{\δ}=\frac{R1}{2L},\mathrm{\ω}=\sqrt{\frac{1}{\mathrm{LC}}-{\left(\frac{R1}{2L}\right)}^2};$

2.: the time constant computing formula of transient current waveform attenuating is:

3.: the instantaneous value computing formula of electric current is:Wherein, I₀It it is the peak value of first crest；

4.: controllable impedance voltage computing formula is $u_L=-\frac{U_c{\mathrm{\ω}}_0}{\mathrm{\ω}}{e}^{-\mathrm{\δt}}\sin (\mathrm{\ωt}-\mathrm{\β});$

Wherein, ${\mathrm{\ω}}_0=\sqrt{{\mathrm{\δ}}^2+{\mathrm{\ω}}^2},\mathrm{\β}=\arctan \left(\frac{\mathrm{\ω}}{\mathrm{\δ}}\right)=\arctan \sqrt{\frac{4L}{{R1}^{2}C}-1};$

By selecting suitable charging voltage U_c, energy-storage capacitor capacity C, controllable impedance L, adjustable resistance R1 and direct current return The electric discharge switching angle on road, can accurately adjust the peak value of transient current, damping time constant parameter, to meet different shaped The requirement of number electronic current mutual inductor relay protection.

Finally should be noted that: described embodiment is only some embodiments of the present application rather than whole realities Execute example.Based on the embodiment in the application, those of ordinary skill in the art are obtained under not making creative work premise Every other embodiment, broadly fall into the application protection scope.

Claims (6)

1. a transient-wave circuit for electronic current mutual inductor big electric current synthesis, described circuit includes controller unit, its Being characterised by, described circuit includes DC charging power supply and the waveform output unit being connected with ECT test product；

Described controller unit includes charge control module, control of discharge module, waveform monitoring modular and transient-wave regulation mould Block；The electronic device output in described waveform output unit of described controller unit adjusts the signal of duty to control waveform Output unit is to described ECT test product output transient voltage waveform and transient current waveform；

Described waveform output unit include being connected to the charging IGCT of the positive terminal of described DC charging power supply, commutator, Electric discharge IGCT, adjustable resistance and controllable impedance；Low sense diverter is connected with the negative pole end of described DC charging power supply.

The transient-wave circuit of the big electric current of a kind of electronic current mutual inductor the most as claimed in claim 1 synthesis, its feature exists In, fly-wheel diode is connected in reverse parallel in described DC charging power supply two ends；One end of described fly-wheel diode is put described in being connected to Between electricity IGCT and adjustable resistance, the other end is connected between the negative pole end of described DC charging power supply and low sense diverter.

The transient-wave circuit of the big electric current of a kind of electronic current mutual inductor the most as claimed in claim 2 synthesis, its feature exists In, the number of described charging IGCT, commutator and electric discharge IGCT is 2；One described charging IGCT, commutator With the series arm of electric discharge IGCT is connected between the positive terminal of described DC charging power supply and described adjustable resistance；Another The series arm of described charging IGCT, commutator and electric discharge IGCT is also connected to the positive terminal of described DC charging power supply And between described adjustable resistance.

The transient-wave circuit of the big electric current of a kind of electronic current mutual inductor the most as claimed in claim 3 synthesis, its feature exists In, described commutator respectively by storage capacitor connect the negative pole end with described DC charging power supply and low sense diverter it Between；

When described charging IGCT is connected with described storage capacitor by described commutator, described DC charging power supply, fill Electricity IGCT and storage capacitor composition charge current loop, be charged described storage capacitor；

When described electric discharge IGCT is connected with described storage capacitor by described commutator, described electric discharge IGCT, energy storage Electric capacity and fly-wheel diode composition discharge current loop, described storage capacitor discharges.

The transient-wave circuit of the big electric current of a kind of electronic current mutual inductor the most as claimed in claim 4 synthesis, its feature exists In, described fly-wheel diode is forward conduction when the voltage zero-cross polarity inversion of transient voltage waveform, so that in voltage mistake During zero point, resonance stops, and discharge current is exponentially decayed, and meets the output requirement of transient voltage waveform.

The transient-wave circuit of the big electric current of a kind of electronic current mutual inductor the most as claimed in claim 4 synthesis, its feature exists In, described charge control module, it is used for controlling commutator feed motion and storage capacitor is filled by charge current loop Electricity；

Described control of discharge module, is used for controlling described commutator feed motion and described storage capacitor is discharged；

Described waveform monitoring modular, gathers the electric current of the low sense diverter of waveform output unit, thus monitors described transient voltage Waveform and described transient current waveform；

Described transient-wave adjustment module, for regulating adjustable resistance and the controllable impedance of waveform output unit, thus to described Transient voltage waveform and described transient current waveform are adjusted.