JPS6119940B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a breaking performance test of a circuit breaker, and more particularly to a circuit breaker equivalence test device for verifying the breaking performance in a region where the arc time exceeds 0.5 cycles. Conventionally, in the breaking performance test of circuit breakers, it is necessary to verify the breaking performance in areas where the arc time exceeds 0.5 cycles. Therefore, in the composite equivalence test, a technique is required to pass through the initial current zero point and reliably extend the arc. Generally, another capacitor is charged in advance, and at the current zero point, the charge is superimposed on the interrupting current as a steep pulse current through a reactor or resistor, and the current zero point is rapidly passed and the arc continues for another half wave. . However, in a circuit breaker with particularly excellent insulation recovery characteristics, the waveform of the pulse current affects the success rate of arc extension, so the success rate of a circuit that generates the pulse current is extremely low.

Therefore, the ideal wavelength is a high frequency of 1 KHz or more, and it is necessary to change the circuit constant of the pulse generation circuit to obtain this wavelength by several + μS. Therefore, new three-point gap control systems and the like have been proposed.

To obtain an ideal superimposed pulse current waveform, it is necessary to make the pulse generation circuit a composite type. In other words, the pulse current of the same polarity to be superimposed on the interrupting current that approaches the zero point has a peak value as large as possible, and the current change rate is negative (di/dt<0) in a time band where the current changes rapidly to the opposite polarity. By doing so, the current passes through the zero point with di/dt that is greater than the breaking capacity of the test circuit breaker CBt. However, the peak value of the next positive half wave (third wave) must be made as small as possible to avoid failure in arc extension due to passing through the zero point again at the rising edge. That is, in the arc extension pulse current waveform, the peak value of the first wave is increased, the current change rate di/dt to the second wave is increased, and the wave tail of the second wave is blunted to increase the third wave peak value. It is requested that it be set to 0.

For this reason, the circuit constants of the pulse generation circuit are changed in a short period of time to satisfy the above requirements, but a three-point gap control method using a timer is used to change the circuit constants midway. is being carried out. However, it has been difficult to perform gap discharge control reliably on the order of 10 μS in order to discharge at the moment of the peak of the AC voltage using a conventional timer.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, an object of the present invention is to provide a circuit breaker equivalence test device that can reliably perform gap discharge control on the order of 10 μS.

Therefore, the present invention provides a circuit breaker equivalence test having an arc extension pulse generation circuit that generates a pulse current to extend the arc by superimposing it on the breaking current near the zero point of the breaking current flowing through the test circuit breaker. In the apparatus, the arc extension pulse generation circuit has a three-point gap for switching circuit constants whose discharge is controlled by detecting a circuit voltage, and in particular, a signal that triggers a predetermined three-point gap among them is used to generate the arc extension pulse. Through a reverse voltage blocking diode that detects when the voltage of the charging capacitor that is the power source of the circuit is reversed, and a nonlinear resistance element whose resistance decreases when the voltage value of the reverse voltage blocking diode exceeds a predetermined value. The purpose of this invention is to provide a circuit breaker equivalence testing device characterized in that it is configured to be connected to one end of the charging capacitor, and will be described below using examples.

FIG. 1 shows an embodiment of the circuit breaker equivalence test device according to the present invention, in which part A is a charging circuit,
Part B is an arc extension pulse generation circuit, part C is a Weyl circuit, and part D is a current source circuit.

First, regarding the configuration of the charging circuit in section A, a rectifying element 14 and a resistor 16 are connected in series to a voltage source 12.

Next, regarding the configuration of the arc extension pulse generation circuit in part _B , a gap (discharge gap) _G1 is connected to one end of the capacitor _C1 charged in the charging circuit part A via a reactor L1, and A gap _G2 is connected to one end of _C1 via a resistor _R1 , and the other end of this gap _G2 is connected to the connection point between the reactor _L1 and the gap _G1 . In addition, the trigger electrode of the gap G ₃ is connected to one end of the capacitor C ₁ via a reverse voltage blocking diode SD and a non-linear resistance element, such as a Zener characteristic element ZD, whose resistance decreases when the voltage value exceeds a predetermined value. has been done. Also resistor R ₁ and gap
The connection point of G ₂ is connected to the other end of capacitor C ₁ through capacitor C ₂ and low resistance R ₂ . A series connection of a capacitor _C3 , a reactor _L3 , and a gap _G3 is connected in parallel with the capacitor _C2 . The connection point between capacitor C ₃ and reactor L ₃ is connected to the trigger electrode of gap G ₂ via resistors R ₃ and R′ ₃ .

Regarding the configuration of the Weyl circuit in section C, the line reactance L ₂ is connected to the other end of the gap G ₁ in section B of the arc extension pulse generation circuit, and the first auxiliary circuit breaker CB ₁
and a test circuit breaker CBt are connected in series, and the other end of the test circuit breaker CBt is connected to the other end of the capacitor _C1 . Test circuit breaker CBt and auxiliary circuit breaker CB ₁
The connection point is connected to the voltage source circuit E via the second auxiliary circuit breaker _CB2 .

Regarding the configuration of the current source circuit in section D, there is an inductance L ₀ between both ends of the current source G such as a generator.
Resistor R ₀ , capacitor C ₀ and third auxiliary circuit breaker
CB ₃ are connected in series. Inductance L ₀
The connection point between the auxiliary circuit breaker CB ₃ and _the current source G is connected to the other end of _{the capacitor C 1 .}

Next, the operation of this embodiment will be explained below. The voltage source 12 connects the capacitor to a predetermined voltage in advance.
C ₁ and C ₂ are charged, and after opening the test circuit breaker CBt, the first current zero point O ₁ of the current I ₁ as shown in Fig. 2 is reached.
When the gap G ₁ is triggered by the arc extension command immediately before, the current shown in Figure 3B determined by the series circuit of capacitor C ₁ - reactor L ₁ - reactor L ₂ (generated from the arc extension pulse generation circuit in section B) A current) I ₂ supplied from the circuit through the reactor L ₂ flows. FIG. 3A is an enlarged view of section P (near the _O1 point) in FIG. 2. Then capacitor C ₁
The point at which the voltage polarity of is almost completely reversed (TμS
When the gap G ₂ is triggered in (after), the current I' ₂ supplied from the arc extension pulse generation circuit B section through the reactor L ₂ is transferred to the capacitor C ₁ - resistor R ₁ -
The waveform is determined by the path of reactor _L2 .
Then, the current I _T (=
I ₁ + I ₂ ) becomes I _T (=I ₁ + I′ ₂ ), and the test circuit breaker CBt
flows to

By the way, the time TμS at which the gap _G2 is triggered is preferably near the maximum value at which the polarity of the voltage V of the capacitor _C1 is completely reversed and the voltage has risen to a voltage sufficient to cause a flashover of the gap _G2 .

Capacitor C _2, which is the power source for the trigger signal of gap G ₂ , is precharged together with capacitor C ₁ . When the gap G ₃ is triggered, the circuit consisting of capacitor C ₂ - capacitor C _{3 -} reactor L ₃ resonates, and the voltage generated by capacitor C ₃ causes resistance.
Gap G ₂ can be triggered via R ₃ and R′ ₃ . Gap G ₂ trigger (blocking, G ₃ toggle), Gap G ₁ trigger (arc extension)
To delay more than TμS, gap the timer circuit.
It is conceivable to start with the command of G ₁ and trigger gap G ₃ at a predetermined time limit, but synchronization is difficult. Therefore, in this embodiment, the reverse voltage blocking diode SD detects that the voltage of the capacitor _C1 is reversed, and when the voltage value of the reverse voltage blocking diode SD exceeds a predetermined value, a nonlinear resistor whose resistance decreases is activated. By connecting a body, for example, a Zener characteristic element ZD, to the trigger electrode of the gap _G3 , the gap _G3 is reliably triggered TμS after the command of the gap _G1 .

According to this embodiment, the three-point gaps G ₂ and G ₃ for switching circuit constants in the arc extension pulse generation circuit B section are reliably controlled by using a circuit voltage detection method using a reverse voltage blocking diode SD. ,
Intended pulse current waveform (increase the peak value of the first wave, increase the current change rate di/dt to the second wave, blunt the tail of the second wave, and increase the peak value of the third wave) ) can be obtained.

As is clear from the above description, according to the present invention, by detecting the circuit voltage, the three-point gap for constant switching of the arc extension pulse generation circuit is
By controlling G ₂ and G ₃ , gap discharge control can be performed reliably on the order of 10 μS, and the desired pulse current waveform described above can be obtained.

[Brief explanation of the drawing]

Fig. 1 is a circuit diagram showing an embodiment of the circuit breaker equivalence test device according to the present invention, Fig. 2 is a current waveform diagram that flows when the test circuit breaker in Fig. 1 is first opened, and Fig. 3 Figure 3B is an enlarged view of section P in Figure 2, Figure 3B is a current waveform diagram supplied from the arc extension pulse generation circuit in Figure 1 via reactor _L2 , Figure 3C is the test circuit breaker in Figure 1. FIG. 3 is a current waveform diagram flowing through CBt. C ₁ to _{C 3} are capacitors, CBt is the test circuit breaker, G ₁
~ _G3 is the gap, _L1 and _L3 are the reactors, _L2 is the stray reactance of the test line, and _R1 to _R3 are the resistances.

Claims (1)

[Claims] 1. In a circuit breaker equivalence test device having an arc extension pulse generation circuit that generates a pulse current to extend the arc by superimposing it on the interrupting current near the zero point of the interrupting current flowing through the test circuit breaker, the arc extension pulse generation The circuit has a three-point gap for circuit constant switching whose discharge is controlled by detecting the circuit voltage, and in particular, a signal that triggers a predetermined three-point gap is applied to a charging capacitor that serves as a power source for the arc extension pulse generation circuit. The voltage is obtained from one end of the charging capacitor through a reverse voltage blocking diode that detects that the voltage is reversed, and a nonlinear resistance element whose resistance decreases when the voltage value of the reverse voltage blocking diode exceeds a predetermined value. A circuit breaker equivalence test device characterized in that it is configured to be connected to.