CN103176105B - Test circuit and method for capacitor internal fuses based on alternating current phase selection - Google Patents

Abstract

The invention discloses a capacitor internal fuse test circuit based on an AC phase selection method and a test method thereof, comprising the following steps: 1) customizing the first capacitor for testing and the second capacitor for testing; 2) selecting the first capacitor, the second Capacitor; 3) Connect to form a fuse test circuit in the capacitor; 3) Turn on the power switch to transmit power, the phase selection circuit breaker detects the measurement signal of the voltage change PT, when the voltage is at the peak value, immediately close the phase selection circuit breaker, the second The capacitor of a test product discharges the internal fuse, and the internal fuse flows through high-frequency and large current instantaneously, and a transient or power-frequency continuous current fusing occurs, and the phase selection circuit breaker is disconnected; 4) The waveform recorder records the waveform of voltage and current, It can calculate the fusing time of the internal fuse and analyze the fusing performance of the internal fuse; 6) Replace the internal fuse and repeat the test to obtain the best internal fuse configuration scheme for the capacitor to be selected. The invention only needs to replace the internal fuses of different specifications, the cost is low, and the operation is simple.

Description

A test circuit and test method for fuses in capacitors based on AC phase selection

technical field

The present invention and a capacitor internal fuse test circuit and test method based on an AC phase selection method belong to the technical field of power capacitors.

Background technique

At present, internal fuses are more and more used in power capacitors. Their function is that when capacitor components fail, the corresponding internal fuses will be blown quickly, isolating the faulty components, protecting other intact components, and ensuring the normal operation of the capacitor. In practical applications, due to unreasonable selection, the internal fuse cannot be blown in time and cannot provide protection. Therefore, when selecting and configuring the internal fuse, tests must be carried out to check its fusing performance. At present, the more commonly used methods include DC voltage piercing method and AC piercing method. Compared with the DC puncture method, the puncture test under AC voltage is more in line with the actual situation. However, because the capacitor element generally breaks down at the peak voltage, the fusing characteristics of the internal fuse need to be tested when the component is pierced at the peak value, which is of little significance for the test at the time of non-peak breakdown. In the AC mode, the voltage phase during mechanical piercing is not easy to be controlled. In order to ensure that the peak pierced capacitors can reach a certain number to test their fusing characteristics, a considerable number of capacitor samples must be provided, the cost is high, and mechanical The piercing method is time-consuming and labor-intensive.

Contents of the invention

The object of the present invention is to provide a capacitor internal fuse test circuit and its test method based on the AC phase selection method. In the AC voltage mode, the peak breakdown of the capacitor element is simulated by closing the phase selection circuit breaker, without using the capacitor The shell is punched and pierced to ensure the validity of each test, so as to save time, effort and cost.

In order to achieve the above object, technical scheme of the present invention is:

A capacitor internal fuse test circuit based on AC phase selection, including test power supply Us, first capacitor C ₁ , second capacitor C ₂ , first sample capacitor C _m-1.1 , second sample capacitor C _{mn- 1.} Rheological CT, phase selection circuit breaker K, internal fuse R, voltage transformer PT, waveform recorder JL; wherein the test power supply Us is connected in series with the first capacitor _C1 and the second capacitor _C2 through a circuit to form a loop ; The capacitor C _m-1.1 of the first sample, the capacitor C _mn-1 of the second sample, and rheological series are connected in parallel with the second capacitor C ₂ ; the phase selection circuit breaker K, the internal fuse R After being connected in series with the second sample capacitor C _mn-1 in parallel; the two ends of the second capacitor _C2 are connected with a voltage transformer PT; the voltage transformer PT is connected to the phase selection circuit breaker K through a line; Waveform recorder JL is connected to rheological CT and pressure variable PT through lines respectively.

A test method for a fuse test circuit in a capacitor based on an AC phase selection method, comprising the following steps: 1) customizing the first capacitor C _m-1.1 and the second capacitor C _mn-1 ; 2) selecting the first Capacitor C ₁ , second capacitor C ₂ ; 3) The first sample capacitor C _m-1.1 , the second sample capacitor C _mn-1 , the first capacitor C ₁ , the second capacitor determined in step 1) and step 2) Capacitor C ₂ is connected with the test power supply Us, rheological CT, phase selection circuit breaker K, internal fuse R, voltage transformer PT, and waveform recorder JL to form a capacitor internal fuse test loop; 3) Turn on the switch of the power supply Us to transmit power, The phase selection circuit breaker K detects the measurement signal of the voltage transformer PT. When the voltage is at the peak value, the phase selection circuit breaker K is closed immediately, and the first sample capacitor C _m-1.1 connected in parallel with it discharges the internal fuse R, and the internal fuse Wire R flows through high-frequency and high-current instantaneously, and a transient or power-frequency freewheeling fuse occurs, and the phase-selection circuit breaker K is disconnected; 4) While step 3) is being carried out, the waveform recorder JL records the waveforms of voltage U and current I According to the waveform of voltage U and current I, the fusing time of internal fuse R can be calculated and the fusing performance of internal fuse R can be analyzed; 6) Replace internal fuse R, repeat step 3) and step 4) test, and integrate all test data , to obtain the best internal fuse configuration scheme of the capacitor Cx to be selected.

The step 1) is specifically to customize the first sample capacitor C _m-1.1 and the second sample capacitor C _mn-1 according to the capacitor Cx to be selected with an element structure of M parallel N series, and the first The process parameters of the sample capacitor C _m-1.1 and the second sample capacitor C _mn-1 are consistent with the capacitor Cx to be selected. In terms of structure, the element structure of the first sample capacitor C _m-1.1 is M-1 and 1 string. The component structure of the second sample capacitor C _mn-1 is M and N-1 strings.

The step 2) specifically selects the first capacitor _C1 and the second capacitor _C2 according to the technical parameters of the capacitor Cx to be selected, and requires the voltage across the second capacitor _C2 to be equal to the capacitor Cx to be selected after the power supply Us is powered on. rated voltage.

The phase selection circuit breaker K is a circuit breaker with a phase selection function, or a circuit breaker with a phase selection controller.

The beneficial effect of the present invention is: a kind of fuse test loop and its test method in the capacitor based on the AC phase selection method of the present invention, in the AC voltage mode, the peak breakdown of the capacitor element is simulated by closing the phase selection circuit breaker, There is no need to punch and puncture the capacitor shell, which can ensure the validity of each test, so as to save time, effort and cost. In the normal test process, it is only necessary to replace the internal fuses of different specifications, and there is no need to make different internal fuse capacitor samples, and it is not necessary to punch holes and puncture the capacitors. The cost is low and the operation is simple.

Description of drawings

FIG. 1 is a structural schematic diagram of a fuse test circuit in a capacitor based on an AC phase selection method according to the present invention.

Detailed ways

Example 1

As shown in Figure 1, a capacitor internal fuse test circuit based on AC phase selection in this embodiment includes a test power supply Us1, a first capacitor _C12 , a second capacitor _C23 , and a first sample capacitor C _m-1.1 4. The second sample capacitor C _mn-1 5. Rheology CT6, phase selection circuit breaker K7, internal fuse R8, voltage transformer PT9, waveform recorder JL10; The first capacitor C ₁ 2 and the second capacitor C ₂ 3 are connected in series to form a circuit; the capacitor C _m-1.1 4 of the first sample, the capacitor C _mn-1 5 of the second sample, and rheology 6 are connected in series with the second The capacitor _C23 is connected in parallel; the phase selection circuit breaker K7 and the internal fuse R8 are connected in parallel with the second sample capacitor Cmn _- 15 after being connected in parallel; an equivalent capacitor is formed to simulate the capacitor Cx to be selected, The phase selection circuit breaker K7 adopts a circuit breaker with a phase selection function (when performing local opening and closing operations or receiving remote opening and closing instructions, it can judge the voltage change measurement signal, and according to the preset closing and opening Phase angle, open and close. The closing phase angle is set to ±90 degrees, and the opening phase angle is not limited); the two ends of the second capacitor C ₂ 3 are connected with a voltage transformer PT9; the voltage transformer PT9 is connected to the phase selection circuit breaker K7 through the line; the waveform recorder JL10 is connected to the rheological CT6 and the voltage transformer PT9 respectively through the line; the voltage transformer PT9 tests the voltage U at both ends of the equivalent capacitor and sends it to the phase selection circuit breaker K7 , Rheological CT6 test flows through the current I.

The test method includes the following steps: 1) Customize the first sample capacitor C _m-1.1 4. The second sample capacitor C _mn-1 5: According to the component structure of the capacitor Cx to be selected in M parallel N series, customize the second capacitor Cx The first sample capacitor C _m-1.1 4, the second sample capacitor C _mn-1 5, and the process parameters of the first sample capacitor C _m-1.1 4 and the second sample capacitor C _mn-1 5 are the same as The to-be-selected capacitors Cx are the same. In terms of structure, the structure of the first sample capacitor C _m-1.1 4 elements is M-1 and 1 series, and the second sample capacitor C _mn-1 5 elements is structure of M and N-1 strings; 2) Select the first capacitor C ₁ 2 and the second capacitor C ₂ 3: select the first capacitor C ₁ 2 and the second capacitor C ₂ 3 according to the technical parameters of the capacitor Cx to be selected, and require the second capacitor after the power supply Us1 is powered The voltage at both ends of C ₂ 3 is equal to the rated voltage of the capacitor Cx to be selected; 3) The first sample capacitor C _m-1.1 4 and the second sample capacitor C _mn-1 5 determined in step 1) and step 2) The first capacitor _C12 , the second capacitor _C23 , the test power supply Us1, rheological CT6, phase selection circuit breaker K7, internal fuse R8, voltage transformer PT9, waveform recorder JL10 are connected to form a capacitor internal fuse test circuit; 3) Turn on the switch of the power supply Us1 to transmit power, the phase selection circuit breaker K7 detects the measurement signal of the voltage transformer PT9, when the voltage is at the peak value (±90 degrees), close the phase selection circuit breaker K7 immediately, and the first test in parallel The product capacitor C _m-1.1 4 discharges the internal fuse R8, and the internal fuse R8 flows through a high frequency and large current instantaneously, and a transient or power frequency freewheeling fuse occurs, and the phase selection circuit breaker K7 is disconnected; 4) In step 3) At the same time, the waveform recorder JL10 records the waveforms of voltage U and current I. According to the waveforms of voltage U and current I, the fusing time of internal fuse R8 can be calculated and the fusing performance of internal fuse R8 can be analyzed; 6) Replace the internal fuse R8, repeat the test of step 3) and step 4), and combine all the test data to obtain the best internal fuse configuration scheme of the capacitor Cx to be selected.

Example 2

As shown in Figure 1, a capacitor internal fuse test circuit based on AC phase selection in this embodiment includes a test power supply Us1, a first capacitor _C12 , a second capacitor _C23 , and a first sample capacitor C _m-1.1 4. The second sample capacitor C _mn-1 5. Rheology CT6, phase selection circuit breaker K7, internal fuse R8, voltage transformer PT9, waveform recorder JL10; The first capacitor C ₁ 2 and the second capacitor C ₂ 3 are connected in series to form a circuit; the capacitor C _m-1.1 4 of the first sample, the capacitor C _mn-1 5 of the second sample, and rheology 6 are connected in series with the second The capacitor _C23 is connected in parallel; the phase selection circuit breaker K7 and the internal fuse R8 are connected in parallel with the second sample capacitor Cmn _- 15; the phase selection circuit breaker K7 adopts a phase selection controller The circuit breaker (when performing local opening and closing operations or receiving remote opening and closing instructions, it can judge the pressure change measurement signal, and open and close according to the preset closing and opening phase angle. The closing phase angle set to ±90 degrees, and the opening phase angle is not limited); the two ends of the second capacitor _C23 are connected with a voltage transformer PT9; the voltage transformer PT9 is connected to the phase selection circuit breaker K7 through a line; the The waveform recorder JL10 is connected to the rheological CT6 and the pressure transformer PT9 respectively through lines.

The test method includes the following steps: 1) Customize the first sample capacitor C _m-1.1 4. The second sample capacitor C _mn-1 5: According to the component structure of the capacitor Cx to be selected in M parallel N series, customize the second capacitor Cx The first sample capacitor C _m-1.1 4, the second sample capacitor C _mn-1 5, and the process parameters of the first sample capacitor C _m-1.1 4 and the second sample capacitor C _mn-1 5 are the same as The to-be-selected capacitors Cx are the same. In terms of structure, the structure of the first sample capacitor C _m-1.1 4 elements is M-1 and 1 series, and the second sample capacitor C _mn-1 5 elements is structure of M and N-1 strings; 2) Select the first capacitor C ₁ 2 and the second capacitor C ₂ 3: select the first capacitor C ₁ 2 and the second capacitor C ₂ 3 according to the technical parameters of the capacitor Cx to be selected, and require the second capacitor after the power supply Us1 is powered The voltage across C ₂ 3 is equal to the rated voltage of the capacitor Cx to be selected; 3) The first test capacitor C _m-1.1 4, the second test capacitor C _mn-1 5 determined in step 1) and step 2), The first capacitor _C12 , the second capacitor _C23 , the test power supply Us1, rheological CT6, phase selection circuit breaker K7, internal fuse R8, voltage transformer PT9, waveform recorder JL10 are connected to form a capacitor internal fuse test circuit; 3) Turn on the switch of the power supply Us1 to transmit power, the phase selection circuit breaker K7 detects the measurement signal of the voltage transformer PT9, when the voltage is at the peak value (±90 degrees), close the phase selection circuit breaker K7 immediately, and the first test in parallel The product capacitor C _m-1.1 4 discharges the internal fuse R8, and the internal fuse R8 flows through a high frequency and large current instantaneously, and a transient or power frequency freewheeling fuse occurs, and the phase selection circuit breaker K7 is disconnected; 4) In step 3) At the same time, the waveform recorder JL10 records the waveforms of voltage U and current I. According to the waveforms of voltage U and current I, the fusing time of internal fuse R8 can be calculated and the fusing performance of internal fuse R8 can be analyzed; 6) Replace the internal fuse R8, repeat the test of step 3) and step 4), and combine all the test data to obtain the best internal fuse configuration scheme of the capacitor Cx to be selected.

In this embodiment, a capacitor internal fuse test circuit and test method based on the AC phase selection mode, in the AC voltage mode, the peak breakdown of the capacitor element is simulated by closing the phase selection circuit breaker, without drilling holes in the capacitor shell And puncture, can guarantee the effectiveness of each test, in order to save time and effort, cost savings. In the normal test process, it is only necessary to replace the internal fuses of different specifications, and there is no need to make different internal fuse capacitor samples, and it is not necessary to punch holes and puncture the capacitors. The cost is low and the operation is simple.

Claims (5)

1., based on the fuse test loop in capacitor exchanging phase selection mode, it is characterized in that comprising experiment power supply Us(1), the first capacitor C ₁(2), the second capacitor C ₂(3), the first test product capacitor C _m-1.1(4), the second test product capacitor C _m.n-1(5), stream become CT(6), phase selection isolating switch K(7), Internal fuse R(8), pressure become PT(9), wave tracer JL(10); Wherein said experiment power supply Us(1) by circuit and the first capacitor C ₁(2) and the second capacitor C ₂(3) primary Ioops is connected into; The first described test product capacitor C _m-1.1(4), the second test product capacitor C _m.n-1(5), stream becomes CT(6) connect rear and the second capacitor C ₂(3) be connected in parallel; Described phase selection isolating switch K(7), Internal fuse R(8) series connection after with the second test product capacitor C _m.n-1(5) be connected in parallel; The second described capacitor C ₂(3) two ends are connected with pressure change PT(9); Described pressure becomes PT(9) by circuit and phase selection isolating switch K(7) be connected; Described wave tracer JL(10) respectively by circuit with stream become CT(6), press become PT(9) be connected.

2. a test method for a kind of fuse test loop in capacitor based on interchange phase selection mode as claimed in claim 1, is characterized in that comprising the steps: 1) customize the first test product capacitor C _m-1.1(4), the second test product capacitor C _m.n-1(5); 2) the first capacitor C is selected ₁(2), the second capacitor C ₂(3); 3) by step 1) and step 2) the first test product capacitor C of determining _m-1.1(4), the second test product capacitor C _m.n-1(5), the first capacitor C ₁(2), the second capacitor C ₂(3) and experiment power supply Us(1), stream become CT(6), phase selection isolating switch K(7), Internal fuse R(8), pressure become PT(9), wave tracer JL(10) be connected to form fuse test loop in capacitor; 4) opening power Us(1) switch power transmission, phase selection isolating switch K(7) detect that pressure becomes PT(9) measuring-signal, when voltage is positioned at peak value, phase selection of closing immediately isolating switch K(7), the first test product capacitor C in parallel with it _m-1.1(4) to Internal fuse R(8) electric discharge, Internal fuse R(8) transient flow crosses high frequency big current, transient state or power frequency continued flow fusing occur, disconnects phase selection isolating switch K(7); 5) while step 3) is carried out, wave tracer JL(10) waveform of recording voltage U and electric current I, the waveform according to voltage U and electric current I can calculate Internal fuse R(8) fusing time and analyze Internal fuse R(8) fusing performance; 6) Internal fuse R(8 is changed), repeat step 4) and step 5) test, comprehensive all test figures, draw the Internal fuse allocation plan treating type selecting capacitor Cx the best.

3. the test method of a kind of fuse test loop in capacitor based on interchange phase selection mode according to claim 2, it is characterized in that described step 1) be specially be M according to component structure and N string treat type selecting capacitor Cx, customize the first test product capacitor C _m-1.1(4), the second test product capacitor C _m.n-1, and the first described test product capacitor C (5) _m-1.1(4), the second test product capacitor C _m.n-1(5) technological parameter is consistent with treating type selecting capacitor Cx, in structure, and the first test product capacitor C _m-1.1(4) component structure is M-1 and 1 string, the second test product capacitor C _m.n-1(5) component structure is M and N-1 string.

4. the test method of a kind of fuse test loop in capacitor based on interchange phase selection mode according to claim 2, is characterized in that described step 2) be specially according to treating that the technical parameter of type selecting capacitor Cx selects the first capacitor C ₁(2), the second capacitor C ₂(3) power supply Us(1, is required) the second capacitor C after power transmission ₂(3) voltage at two ends equals the rated voltage treating type selecting capacitor Cx.

5. the test method of a kind of fuse test loop in capacitor based on interchange phase selection mode according to claim 2, it is characterized in that described phase selection isolating switch K(7) adopt the isolating switch with phase-selecting function, or the one in the isolating switch of band phase-controlled device.