JPH01292274A - Synthetic tester for small leading current breaking test - Google Patents

Abstract

PURPOSE:To inspect the cut-off capacity of a small leading current in a state near to a use state, by a method wherein AC voltage is applied to the terminal on a power supply side of a breaker tested after a current is cut off and, at the same time, voltage on a load side is applied to the other terminal from a DC voltage source condenser. CONSTITUTION:A delay current is supplied to a breaker 5 tested from a current source circuit 14 through an auxiliary breaker 6b and, further, a delay current is supplied from the voltage source circuit 13 on a power supply side connected to the current source circuit 14 in parallel. The breaker 5 tested and auxiliary breakers 6a, 6b are opened and a current is cut off while the current source circuit 14 is separated to apply high voltage to the single pole of the breaker 5 tested from the voltage source circuit 13 on the power supply side. DC voltage is applied to the junction point of the breaker 5 tested and the auxiliary breaker 6a from the preliminarily charged condenser 10 of the voltage supply circuit 15 on the load side. By this method, the voltage equal to the voltage applied when a small leading current is cut off is applied between the electrodes of the breaker 5 being tested.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Field of Application) The present invention relates to a synthetic test device for advanced small current interruption testing of circuit breakers, and particularly to a method that is suitable for actual usage conditions in circuit breaker systems. The present invention relates to a synthetic test device for advanced small current interrupting tests of circuit breakers capable of verifying advanced small current interrupting performance.

(Prior Art) Generally, when opening/closing an unloaded power transmission line, power cable, etc., a circuit breaker interrupts the charging current of the ground capacitance, that is, the leading current. When verifying the performance of such a circuit breaker at a test site, a small current interruption test is performed using a capacitor bank as a load instead of the ground capacitance of a power transmission line or power cable. The test circuit is shown in FIG. 3, and the phenomenon at the time of interruption is shown in FIG. 4, and will be explained. The short-circuit generator 1 of the test power source is connected to one end of the test circuit breaker 5, and the load capacitor lOb is connected to the other end. When the test circuit breaker 5 is opened at time t1, the current is cut off at the zero point t2 of the breaking current ρ, and the load side voltage v1 becomes the peak value EII of the power source side voltage Vs. The interpole voltage VP of the test circuit breaker 5 changes by E■(1-cosωt) as the power supply side voltage Vs changes. This value increases to twice the peak value of the power supply voltage after 1/2 cycle of the power supply frequency. In this way, a direct test of the advanced small current interruption test is performed.

However, with the increase in the voltage and capacity of electric power systems, a huge amount of capacitor capacity is required in order to proceed with direct testing and perform small current interruption tests. For this reason, in order to make up for the lack of capacitor capacity, a synthetic test method that allows testing without increasing capacitor capacity has been devised and advanced small current interruption tests are being carried out at test sites. However, synthetic tests have advantages and disadvantages, and there are many problems.

A synthetic test circuit for a typical advanced small current interruption test, which is also described in JEC-2300, is shown in FIG. 5, and the phenomenon during interruption is shown in FIG. 6 and will be explained. Short-circuit generator 1 as test power source
is connected to the low voltage winding of the current source transformer 3b via the current limiting reactor 2, and connected to the high voltage winding via the auxiliary circuit breaker 6 to the test circuit breaker 5, and the other pole is grounded to determine the magnitude of the breaking current. A current source circuit 14 is configured to supply the portion. In addition, the short circuit generator 1 is connected to the low voltage winding of the voltage source transformer 3a, and the high voltage winding of the voltage source transformer 3a is connected to the test circuit breaker 5 via the voltage source capacitor 10a, so that the breaking current p is interrupted. After that, a voltage source circuit 13a for applying voltage is configured. Breaking current■
ρ is the delayed current source current Ii flowing from the current source circuit 14
The current is the sum of the leading voltage source current Iv flowing from the voltage source circuit 13a. Generally, the voltage source current Iv
is set at about 5 to 10% of the interrupting current Ip. The test circuit breaker 5 opens at time t1 and breaks at the zero point of the breaking current IP. At this time, the auxiliary circuit breaker 6 is also cut off at the same time, and the current source circuit 1
4 is separated. Further, the terminal voltage v1 of the voltage source capacitor LOa of the voltage source circuit 13a is the peak value Em of the power supply side voltage Vs, and the voltage between poles VP of the test circuit breaker 5 is the power supply voltage V
As s changes, Em (1-cos ωt) changes, and a voltage equivalent to a direct test is applied. Therefore, a few percent of direct tests
Large capacity lead and small current interruption tests can be performed with a capacitor capacity of . However, ω is the angular frequency of the power source. However, according to this synthetic test device, since one pole of the test circuit breaker 5 is grounded, the test voltage is applied only from one pole, and the voltage is different from that of the circuit breaker in use in the system. It becomes an impression. In addition, since the voltage is applied from one pole, the ground voltage becomes severe, and depending on the test voltage, the voltage value of 2Em may exceed the peak value of the commercial frequency withstand voltage. In this case, this circuit advances and is not suitable for small current interruption tests. Can not.

(Problems to be Solved by the Invention) According to the synthetic test device for the advanced small current interruption test of the circuit breaker described above, after the current is interrupted, voltage is applied from one pole, resulting in a test that is different from the state in which it is used in the system.6 The present invention The purpose of
An object of the present invention is to provide a synthetic test device for advanced small current interruption testing of circuit breakers that enables testing in conditions close to the conditions in which the circuit breaker is used.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, according to the present invention, a test circuit breaker and a first auxiliary circuit breaker are connected in series, and one terminal of the first circuit breaker is grounded. Then, a delayed □ current is supplied from a current source circuit having a short-circuit generator through a second auxiliary circuit breaker. Further, a delayed current is supplied from a power supply side voltage source circuit connected in parallel with the current source circuit, and a current added to the current of the current source circuit is supplied as a cutoff current. The test breaker, the first auxiliary breaker, and the second auxiliary breaker are opened, the current is cut off, and the current source circuit is disconnected. An AC voltage is applied, and by applying a DC voltage from a pre-charged capacitor of the load side voltage source circuit to the connection point of the test circuit breaker and the first auxiliary circuit breaker, a small current flows between the electrodes of the test circuit breaker. It is characterized by being able to apply a voltage equivalent to the voltage applied at the time of interruption, and performing a small current interruption test under conditions close to the conditions in which the circuit breaker is used in the system.

(Function) According to the test equipment configured as described above, voltage was not applied only from one pole of the test circuit breaker.

By applying voltage from both poles, it is possible to proceed in a state closer to the usage state of the circuit breaker in the system, making it possible to verify the small current breaking performance.

(Example) Examples of the present invention will be described below with reference to FIGS. 1 and 2. In Fig. 1, short circuit generator 1 is connected to current limiting reactor 2.
a to the low voltage side of the voltage source transformer 3a, and a series circuit of a transient recovery voltage adjustment resistor 4a and a transient recovery voltage adjustment capacitor 4b is connected to the high voltage side to form the power supply side voltage source circuit 1.
3. Further, the short-circuit generator 1 is connected to the low voltage side of the current source transformer 3b via the current limiting reactor 2b, and connected in parallel to the high voltage side of the voltage source transformer 3a via the auxiliary circuit breaker 6b to the high voltage side. A circuit 14 is configured. From the connection point 11a between the voltage source circuit 13 and current source circuit 14 on the power supply side, the circuit passes through the test breaker 5 and the auxiliary breaker 6a, and in the circuit at the grounding point 12, one pole of the auxiliary breaker 6a is grounded. Further, a load-side voltage source circuit 15 is connected between the connection point 11b of the test circuit breaker 5 and the auxiliary circuit breaker 6a and the ground point 12. Load side voltage source circuit 1
5 connects a series circuit of a waveform adjustment capacitor 8, a waveform adjustment resistor 7, a starting cap 9, and a DC voltage source capacitor 10 between the connection point 11b and the ground point 12.

The starting gap 9 includes a current zero point detection device 9a and a starting control device 9b. Although not shown, the DC voltage source capacitor 10 is equipped with a charging device.

Next, the operation of the invention will be explained with reference to FIGS. 1 and 2. The short-circuit generator 1 is excited and the current-limiting reactors 2a, 2b are supplied with a specified cutoff current rp and a specified recovery voltage peak value Effl from the power supply side voltage source circuit 13 and current source circuit 14.
, and the taps of the voltage source transformer 3a and current source transformer 3b. At this time, the voltage of the current source is such that the breaking current IP is the test circuit breaker 5 and the auxiliary circuit breaker 6a.

For example, in a gas circuit breaker, the arc voltage is about 2 to 3 KV, and a supply voltage that is not affected by an arc voltage of about 10 KV is required. It is necessary to some extent. Test circuit breaker 5 and auxiliary circuit breakers 6a, 6
b is set to be cut off at the current zero point t2 of the cutoff current Ip, and opened at tl. When the cutoff current Ip is cut off, the power supply voltage Vs is applied from the power supply voltage source circuit 13 to the connection point 11a of the test breaker 5, and the transient recovery voltage begins to rise.

The transient recovery voltage waveform can be adjusted by the transient recovery voltage adjustment resistor 4a and the transient recovery voltage adjustment capacitor 4b.

Immediately after the interruption at the current zero point t2 of the interruption current Ip,
The current zero point is detected by the current zero point detection device 9a, and the starting gap 9 is started by the starting control device 9b. The pre-charged DC voltage source capacitor 10 is discharged and the load side voltage Em
In order to apply the voltage, the waveform adjustment capacitor 8 is charged with a DC voltage. The polarity of this DC voltage is the same as the transient recovery voltage of the power supply side voltage Vs, and the rise of the voltage is adjusted by a waveform adjustment resistor 7 and a waveform adjustment capacitor 8. The transient recovery voltage adjustment of the power supply side voltage Vs and the waveform adjustment of the load side voltage Vl are adjusted so that the potential difference between the respective voltage rising portions is minimized. In this way, the power supply side voltage Vs and the load side type rf:, vl are applied to the test circuit breaker 5. When the load side voltage Vl reaches the peak value Em, the voltage VP between the poles of the test circuit breaker 5 becomes approximately Eo+(1-cosωt) and advances to obtain a voltage equivalent to the voltage between the poles when interrupting a small current.

〔Effect of the invention〕

As explained above, according to the present invention, a delayed current is supplied from an AC power supply, and after the current is cut off, an AC voltage is applied to the power supply side terminal of the circuit breaker under test, and at the same time, a pre-charged DC voltage source By applying the load side voltage from the capacitor to the other terminal, the voltage between electrodes when cutting off a small leading current is 11
It is possible to provide a synthetic test device for a small leading current test of a circuit breaker, which can apply an equivalent voltage and can perform a small leading current test in a manner consistent with the actual usage conditions in a circuit breaker system.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram of a synthetic test device for advanced small current test showing an embodiment of the present invention, Fig. 2 is a voltage and current waveform diagram at the time of interruption in the circuit shown in Fig. 1, and Fig. 3 is a general diagram. Figure 4 is a voltage and current waveform diagram at the time of interruption in the circuit shown in Figure 3, Figure 5 is a circuit diagram of a conventional synthetic test device for a small lead current test, and Figure 6 is a circuit diagram of a leading small current test. 6 is a diagram of cutoff dark voltage and current waveforms in the circuit shown in FIG. 5. FIG. 1... Short circuit generator, 2a, 2b... Current limiting reactor, 3a... Voltage source transformer, 3b.
... Gradual current JE device, 4a... Resistor for adjusting transient recovery voltage, 4b... Capacitor for adjusting transient recovery voltage, 5... Test breaker, 6a, 6b... Auxiliary circuit breaker. 7... Resistor for waveform adjustment, 8... Capacitor for waveform adjustment, 9... Starting cap, 9a... Current zero point detection device, 9b... Starting control device, 10.
...DC voltage source capacitor, 11a, llb... connection point, 12... grounding point, 13... power supply side voltage source circuit, 14... current source circuit, 15... load side voltage source circuit . Agent Patent Attorney Yudo Ken Chika Ken Daikomaru Figure 2 τ Figure 3 Figure 4 τ Figure 5

Claims (1)

[Claims] An AC power supply serving as a test power supply, a first test transformer to which a low voltage winding is connected to the AC power supply, a test circuit breaker connected to the high voltage winding of the first test transformer, and a first auxiliary test transformer. A power supply side voltage source circuit that connects the series circuit of the circuit breaker and the other terminal of the first auxiliary circuit breaker is grounded to form a closed circuit, and the AC power supply is connected in parallel with the low voltage winding of the first test transformer. The low voltage winding of the second test transformer is connected to the current source circuit, and the second auxiliary circuit breaker is connected to the high voltage winding of the second test transformer. The other terminal is connected to the connection between the first test transformer and the circuit breaker under test, and the other terminal of the second test transformer is connected to a circuit connected to a ground point and a predetermined voltage. A circuit breaker comprising a starting gap from a first capacitor charged to 1, connected to both ends of a second capacitor through a resistor, and a load-side voltage source circuit having both ends connected to both ends of the first auxiliary circuit breaker. Composite test device for small current interruption test.