Circuit breaker on-off test loop

Abstract

The utility model relates to a circuit breaker on-off test loop. The circuit breaker is suitable for the technical field of circuit breakers. The technical problem to be solved by the application is to provide a circuit breaker on-off test loop. According to the technical scheme, the circuit breaker on-off test loop is characterized in that the circuit breaker on-off test loop comprises an alternating current power supply E, an inductor L1, a capacitor C1, a boosting transformer T, a resistor R, an auxiliary circuit breaker Q1 and a tested circuit breaker Q2, and the alternating current power supply E forms a test main loop through the inductor L1, the auxiliary circuit breaker Q1 and the tested circuit breaker Q2; one end of a primary side winding N1 of the boosting transformer T is connected with the power supply side of the auxiliary circuit breaker Q1, the other end of the primary side winding N1 of the boosting transformer T is connected with the alternating current power supply E, and the capacitor C1 is connected with the primary side winding N1 of the boosting transformer T in parallel; and a secondary side winding N2 of the boosting transformer T is connected in parallel with two ends of the tested circuit breaker Q2 through a resistor R.

Description

Technical Field

[0001] The utility model relates to the technical field of circuit breakers, in particular to a circuit breaker breaking test circuit. Background Art

[0002] The short-circuit breaking test of the circuit breaker is a key test of the circuit breaker. It is a test that must be done for each new circuit breaker product, and spot checks will also be conducted at the application site. The short-circuit breaking test methods are divided into direct method and synthetic method. The direct method is that the test voltage, current, and recovery voltage are all obtained from the actual operating power grid. This method is the most direct and effective, but it will affect the normal operation of the power grid and is generally not used. The synthetic method is mostly a pre-test of two or more test circuits specially designed. Specifically, the current is obtained from a current source, and the transient recovery voltage and power frequency recovery voltage are obtained from another power source. The test process is relatively complicated, and the accuracy depends on the circuit switching consistency. Utility Model Content

[0003] The technical problem to be solved by the utility model is: to provide a circuit breaker breaking test circuit in view of the above-mentioned existing problems.

[0004] The technical solution adopted by the utility model is: a circuit breaker breaking test circuit, characterized in that it includes: an AC power supply E, an inductor L1, a capacitor C1, a step-up transformer T, a resistor R, an auxiliary circuit breaker Q1, and a tested circuit breaker Q2, wherein the AC power supply E forms a test main circuit through the inductor L1, the auxiliary circuit breaker Q1, and the tested circuit breaker Q2;

[0005] One end of the primary winding N1 of the step-up transformer T is connected to the power supply side of the auxiliary circuit breaker Q1, the other end of the primary winding N1 of the step-up transformer T is connected to the AC power supply E, and the capacitor C1 is connected in parallel with the primary winding N1 of the step-up transformer T;

[0006] The secondary winding N2 of the step-up transformer T is connected in parallel to both ends of the tested circuit breaker Q2 through a resistor R.

[0007] In some embodiments, a ratio N2 / N1 of the secondary winding N2 of the step-up transformer T to the primary winding N1 thereof is 5-10.

[0008] In some embodiments, the resistance of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

[0009] Another technical solution adopted by the utility model is: a circuit breaker breaking test circuit, characterized in that it includes: an AC power supply E, an inductor L1, a capacitor C1, a step-up transformer T, a resistor R, an auxiliary circuit breaker Q1, and a tested circuit breaker Q2, wherein the first end of the AC power supply E is connected to the first end of the primary winding N1 of the step-up transformer T through the inductor L1, and the second end of the AC power supply E is connected to the second end of the primary winding N1 of the step-up transformer T;

[0010] The capacitor C1 is connected in parallel to both ends of the primary winding N1 of the step-up transformer T;

[0011] The first end of the secondary winding N2 of the step-up transformer T is connected to the first end of the tested circuit breaker Q2 via the resistor R, and the second end of the secondary winding N2 of the step-up transformer T is connected to the second end of the tested circuit breaker Q2;

[0012] The first end of the auxiliary circuit breaker Q1 is connected to the first end of the primary winding N1 of the step-up transformer T, and the second end of the auxiliary circuit breaker Q1 is connected to the first end of the tested circuit breaker Q2.

[0013] In some embodiments, a ratio N2 / N1 of the secondary winding N2 of the step-up transformer T to the primary winding N1 thereof is 5-10.

[0014] In some embodiments, the resistance of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

[0015] The beneficial effects of the utility model are:

[0016] 1. Through the open and closed states of the auxiliary circuit breaker Q1 and the tested circuit breaker Q2, the test circuit presents different loops. First, disconnect the auxiliary circuit breaker Q1. With the characteristic that the current in the inductor L1 cannot change suddenly, the capacitor C1 and the primary winding N1 of the step-up transformer T are charged. The secondary winding N2 of the step-up transformer T induces a voltage, and the tested circuit breaker Q2 obtains the test short-circuit current. After a certain period of time, disconnect the tested circuit breaker Q2. Both ends of the tested circuit breaker Q2 will bear the voltage of the secondary winding N2 of the step-up transformer T, thereby simulating the test recovery voltage borne by the circuit breaker when it is disconnected. Therefore, only one AC power supply is used to obtain the short-circuit current and recovery voltage required for the test.

[0017] 2. The test circuit is simple and reliable, and the adjustment is convenient. At the same time, the test power supply voltage is low and the safety is high. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1It is a schematic diagram of the structure of this application.

[0019] Figure 2 This is the circuit schematic when both Q1 and Q2 are closed.

[0020] Figure 3 This is the circuit schematic when both Q1 and Q2 are disconnected.

[0021] This specification includes references to "one embodiment" or "an embodiment." The appearance of the phrase "in one embodiment" or "in an embodiment" does not necessarily refer to the same embodiment. The particular features, structures or characteristics may be combined in any suitable manner consistent with the present disclosure.

[0022] The term "comprising" is open ended. As used in the appended claims, the term does not exclude additional structures or steps. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand the technical solution of the present utility model, the technical solution of the present utility model is further described below in conjunction with specific embodiments.

[0024] Embodiment 1:

[0025] like Figure 1 As shown, this embodiment is a circuit breaker breaking test circuit, including: an AC power supply E, an inductor L1, a capacitor C1, a step-up transformer T, a resistor R, an auxiliary circuit breaker Q1, and a tested circuit breaker Q2. The AC power supply E forms a test main circuit through the inductor L1, the auxiliary circuit breaker Q1, and the tested circuit breaker Q2; one end of the primary winding N1 of the step-up transformer T is connected to the power side of the auxiliary circuit breaker Q1, and the other end of the primary winding N1 of the step-up transformer T is connected to the AC power supply E, and the capacitor C1 is connected in parallel with the primary winding N1 of the step-up transformer T; the secondary winding N2 of the step-up transformer T is connected in parallel to both ends of the tested circuit breaker Q2 through the resistor R.

[0026] In some embodiments, a ratio N2 / N1 of the secondary winding N2 to the primary winding N1 of the step-up transformer T is 5-10.

[0027] In some embodiments, the resistor R is a phase-shifting resistor, and the resistance of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

[0028] Embodiment 2:

[0029] like Figure 1As shown, this embodiment is a circuit breaker breaking test circuit, comprising: an AC power source E, an inductor L1, a capacitor C1, a step-up transformer T, a resistor R, an auxiliary circuit breaker Q1, and a tested circuit breaker Q2, wherein a first end of the AC power source E is connected to a first end of a primary winding N1 of the step-up transformer T via the inductor L1, and a second end of the AC power source E is connected to a second end of the primary winding N1 of the step-up transformer T; the capacitor C1 is connected in parallel to both ends of the primary winding N1 of the step-up transformer T; a first end of a secondary winding N2 of the step-up transformer T is connected to a first end of the tested circuit breaker Q2 via the resistor R, and a second end of the secondary winding N2 of the step-up transformer T is connected to a second end of the tested circuit breaker Q2; a first end of the auxiliary circuit breaker Q1 is connected to a first end of the primary winding N1 of the step-up transformer T, and a second end of the auxiliary circuit breaker Q1 is connected to a first end of the tested circuit breaker Q2.

[0030] In some embodiments, a ratio N2 / N1 of the secondary winding N2 to the primary winding N1 of the step-up transformer T is 5-10.

[0031] In some embodiments, the resistor R is a phase-shifting resistor, and the resistance of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

[0032] Embodiment three:

[0033] This embodiment is a control method for opening a circuit breaker test circuit, comprising the following steps:

[0034] The AC power supply E forms a test main circuit through the inductor L1, auxiliary circuit breaker Q1 and the tested circuit breaker Q2.

[0035] like Figure 2 As shown, at the beginning of the test, the auxiliary circuit breaker Q1 and the tested circuit breaker Q2 are closed. At this time, the step-up transformer T and the capacitor C1 are bypassed, and there is no voltage and current. The current is gradually increased to the test breaking current, and the auxiliary circuit breaker Q1 is disconnected. At the moment when the auxiliary circuit breaker Q1 is disconnected, since the current of the inductor L1 cannot change suddenly, it will charge the capacitor C1 and the primary winding N1 of the step-up transformer T, so that the secondary winding N2 of the step-up transformer T induces a voltage, which is limited by the phase-shifting resistor R, so that the tested circuit breaker Q2 still maintains the test short-circuit current, and the current is resistive.

[0036] like Figure 3 As shown, the auxiliary circuit breaker Q1 is disconnected, and after an interval time t (t = 10 ~ 15μs), the tested circuit breaker Q2 is disconnected. At this time, both ends of the tested circuit breaker Q2 will be subjected to the voltage of the secondary winding N2 of the step-up transformer T, thereby simulating the test recovery voltage that the circuit breaker should withstand when disconnected.

[0037] The above are all preferred embodiments of the present utility model, and are not intended to limit the protection scope of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the protection scope of the present utility model.

Claims

1. A circuit breaker breaking test circuit, characterized in that: include: AC power source E, inductor L1, capacitor C1, step-up transformer T, resistor R, auxiliary circuit breaker Q1, and tested circuit breaker Q2. The AC power source E forms a test main circuit through the inductor L1, auxiliary circuit breaker Q1, and tested circuit breaker Q2. One end of the primary winding N1 of the step-up transformer T is connected to the power supply side of the auxiliary circuit breaker Q1, the other end of the primary winding N1 of the step-up transformer T is connected to the AC power supply E, and the capacitor C1 is connected in parallel with the primary winding N1 of the step-up transformer T; The secondary winding N2 of the step-up transformer T is connected in parallel to both ends of the tested circuit breaker Q2 through a resistor R.

2. A circuit breaker breaking test circuit according to claim 1, characterized in that: The ratio N2 / N1 of the secondary winding N2 of the step-up transformer T to the primary winding N1 thereof is 5-10.

3. A circuit breaker breaking test circuit according to claim 1, characterized in that: The resistance value of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

4. A circuit breaker breaking test circuit, characterized in that: include: An AC power source E, an inductor L1, a capacitor C1, a step-up transformer T, a resistor R, an auxiliary circuit breaker Q1, and a tested circuit breaker Q2, wherein a first end of the AC power source E is connected to a first end of a primary winding N1 of the step-up transformer T via the inductor L1, and a second end of the AC power source E is connected to a second end of a primary winding N1 of the step-up transformer T; The capacitor C1 is connected in parallel to both ends of the primary winding N1 of the step-up transformer T; The first end of the secondary winding N2 of the step-up transformer T is connected to the first end of the tested circuit breaker Q2 via the resistor R, and the second end of the secondary winding N2 of the step-up transformer T is connected to the second end of the tested circuit breaker Q2; The first end of the auxiliary circuit breaker Q1 is connected to the first end of the primary winding N1 of the step-up transformer T, and the second end of the auxiliary circuit breaker Q1 is connected to the first end of the tested circuit breaker Q2.

5. A circuit breaker breaking test circuit according to claim 4, characterized in that: The ratio N2 / N1 of the secondary winding N2 of the step-up transformer T to the primary winding N1 thereof is 5-10.

6. A circuit breaker breaking test circuit according to claim 4, characterized in that: The resistance value of the resistor R is greater than the power frequency inductive reactance of the secondary winding N2 of the step-up transformer T, so that the resistive current of the secondary winding N2 loop of the step-up transformer T is greater than the inductive current.

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