JPH0755898A - Method of synthetic shortcircuit test of circuit breaker - Google Patents

Abstract

PURPOSE:To expand the application of the double circuit method up to 84kV to all circuit breakers which are equal or above 100-kV. CONSTITUTION:A high-voltage side coil winding of a booster transformer TF1 of a power supply circuit in the double circuit method is set to a double coil winding with a transformation ratio of 0.715:0.285 (JEC-2300 target) or 0.67:0.33 (IEC-56 target) for cascade connection and then capacitors C1 and C2 are connected to each coil winding on the high-voltage side so that 4 parameter TRV waveform of synthetic shortcircuit test standard which is equal to or above 100kV can be generated at the high-voltage side terminal. When performing test according to the double circuit method, a four parameter TRV waveform for satisfying the synthetic shortcircuit test standard which is equal to or above 100kV is generated at the high-voltage side terminal of the booster transformer TF1. Therefore, the double circuit which was applied to only the synthesis test with a rated voltage of 84kV or less can be applied and expanded to all circuit breakers with a rated voltage of 100kV or higher.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a synthetic short circuit test method for circuit breakers.

[0002]

2. Description of the Related Art A conventional double circuit method (Skeet's method) of a circuit breaker is shown in FIG. In this test, a short circuit current is supplied from the current limiting generator AG to the test circuit breaker SP through the protective circuit breaker S ₁ , the current limiting reactor L ₁ , the closing device S ₂ , and the auxiliary circuit breaker Sh, and the auxiliary circuit breaker Sh is supplied. Also, the test breaker SP is opened simultaneously and the secondary high voltage of the step-up transformer TF ₂ is applied to the test breaker SP via the short circuit current suppressing resistor RS. The transient recovery voltage (TRV) is adjusted by the TRV adjustment capacitor C.

This double circuit method is widely used for development test of circuit breakers, especially vacuum circuit breaker (VCB) (IEC42).
7-P81 to P84). In addition to the rated breaking test, it has also been applied and actually used in advanced current breaking synthetic tests. This method has the advantage that existing equipment can be used and that the voltage source circuit does not need to be synchronized, and it can be applied to interruptions with a long arc time to some extent.

[0004]

The above-mentioned double circuit method is intended for a transient recovery voltage of a single frequency (two parameters) and can be applied to a circuit breaker up to 84 kV. 100 kV
With regard to the above circuit breaker, the four-parameter TRV is a standard value, so that other test methods (direct test, Weil test, Siemens I / II test method) had to be resorted to.

The present invention has been made in view of the above problems of the prior art, and an object thereof is to make the double circuit method applicable to all circuit breakers having a rated voltage of 100 kV or more. It is to provide a synthetic test method for a circuit breaker.

[0006]

In order to achieve the above object, the synthetic test method of the circuit breaker according to the present invention is such that the high voltage side winding of the step-up transformer of the voltage source circuit in the double circuit method has a transformer ratio of 0.715. : 0.285 (target for JEC-2300) or 0.67: 0.33 (target for IEC-56) connected in cascade, and the high-voltage side terminal has a 4-parameter TRV waveform of 100 kV or more of synthetic test standard. A capacitor is connected to each of the windings so as to emit.

[0007]

In the test by the double circuit method, when the short circuit current flowing through the circuit breaker under test is cut off, a 4-parameter TRV waveform satisfying the synthetic test standard of 100 kV or more is generated at the high voltage side terminal of the step-up transformer. Therefore, the double circuit method, which was conventionally applicable only to the synthetic test of 84 kV or lower rated voltage, can be applied to the circuit breakers of all rated voltages of 100 kV or higher.

[0008]

Embodiments of the present invention will be described with reference to the drawings.
In FIG. 1, AG is a short-circuit generator, S ₁ is a protective circuit breaker,
L ₂ is a current limiting reactor, S ₂ is a make-up device, Sh and Sp are auxiliary breakers and test breakers connected in series between make-up device S ₂ and ground, and TF ₁ is between make-up device S ₂ and ground. The connected step-up transformer, R _S, is a short-circuit suppressing resistor (200 Ω ~ 200 Ω connected between the high-voltage side output terminal 2 of the step-up transformer and the circuit breaker under test.
10 KΩ).

The high voltage side winding of the step-up transformer TF ₁ is winding n ₁
And n ₂ in series, and TRV adjusting capacitors C ₁ and C ₂ are connected to the windings n ₁ and n ₂ , respectively.

The high-voltage side transformer ratio of the step-up transformer TF ₁ (n ₂ /
n ₁ ) is 0.715: 0.285 (JEC2300 target) or 0.67: 0.33 (IEC56 target). (This constant is a value obtained from the TRV amplitude ratio of 1.4 in JEC2300 or 1.5 in IEC56.) The circuit breaker S is used for the TRV adjusting capacitors C ₁ and C _2.
The voltage generated at the high voltage side terminal of the step-up transformer TF ₁ when h and Sp are opened matches the voltage u ₁ , uc and the time t ₁ , t ₂ of the four-parameter transient recovery voltage waveform of the synthetic test standard of 100 kV or more. Select a capacitor with an appropriate capacitance.

An example of calculating the capacitances of the capacitors C ₁ and C _{2 under the} condition of 168 kV-40 kA and 100% rated cutoff is shown below.

U ₁ / t ₁ = 206 kV / 103 μs, uc
/ T ₂ = 288 kV / 309 μs, t ₁ / t ₂ = 1/3,
n ₁ = 13.2 kV / 196 kV, n ₂ = 13.2 kV /
80kV, 198kV / 80kV = 0.71 / 0.29 Z L = 0.4 a generator voltage 6kV-40 kA current
8 ^mH , and c ₁ / c ₂ is calculated from this.

From f = 0.8 / (2T), f = 0.8 /
^{(2 × 103 × 10 -6)} = 3.88kH Z, C 1 = 1 /
From ((2πf ² ) L), C ₁ ≈15770PF. When C _{2 is obtained} by the same method, C ₂ = 0.84 μF.
t ₁ and t ₃ are triple harmonic vibrations, and the specified voltages u ₁ and u
c is superimposed.

As described above, since the high-voltage side transformation ratio n ₂ / n ₁ of the step-up transformer is determined and the values of the TRV adjusting capacitors c ₁ and c ₂ are selected, a plurality of TRV swing ratios specified in JEC2300 or IEC56 are selected. Frequency (4 parameters) TRV
Waveforms can be obtained. Therefore, by the duplicated circuit method, 1
It has become possible to test circuit breakers with a rated voltage of 00 kV or higher.

[0015]

Since the present invention is configured as described above, it has the following effects.

(1) The double circuit method, which has been conventionally applicable only to the synthetic test of 84 kV or lower rated voltage,
The application will be expanded to circuit breakers of all rated voltages of 100 kV and above.

(2) In the conventional double circuit method, a single frequency (2
The TRV waveform obtained only with the parameter) can be used as a multi-frequency (4 parameter) TRV waveform.

(3) It is very economical because it can be applied to all circuit breakers with a slight modification to the existing double circuit method equipment.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing an embodiment of the present invention.

FIG. 2 is a circuit diagram showing a conventional example.

[Explanation of symbols]

AG ... shorting the generator L ₁ ... limiting reactor R _S ... short-circuit current suppressing resistor S ₁ ... protection breaker S ₂ ... insertion unit Sh ... auxiliary breaker Sp ... test breaker TF _1, TF ₂ ... step-up transformer C, C _1, C ₂ ... TRV (transient recovery voltage) adjustment capacitor

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Mitsuyasu Shiozaki 2-17 Osaki, Shinagawa-ku, Tokyo Incorporated company Meidensha

Claims (1)

[Claims] 1. A dual circuit method for performing a synthetic test of a circuit breaker using a current source circuit connected to a short-circuit generator and a voltage source circuit using a step-up transformer, wherein a high-voltage side winding of the step-up transformer is transformed. Ratio 0.715:
Cascade connection is made as two windings of 0.285 or 0.67: 0.33, and a capacitor is provided in each winding so that a 4-parameter transient recovery voltage waveform of 100 kV or more of synthetic test standard is generated at the high voltage side terminal. A synthetic test method for circuit breakers, characterized in that the circuit breakers of 100 kV or more can be tested by a double circuit method by connecting them.