A capacitor state online testing device for capacitor batch aging

Abstract

The present invention provides an online capacitor state test device for batch aging of capacitors, wherein a plurality of capacitors are arranged in a matrix formation. Each row and each column are respectively provided with a horizontal connecting line and a vertical connecting line; one end of a plurality of capacitors in the same row is connected to the same horizontal connecting line, and the other end of a plurality of capacitors in the same column is connected to the same vertical connecting line; a horizontal connecting line is connected to the common end of a horizontal relay, and the normally-on end of the horizontal relay is connected to a power supply; a vertical connecting line is connected to one end of a test meter, and the other end of the test meter is connected to the normally-on end of the vertical relay. In the case of capacitor testing, the horizontal relay connected to the capacitor to be tested is in a normally-on state, and the other horizontal relays are in a normally-off state, so that the test meter reads the current of the circuit where the capacitor to be tested is located. The present invention can achieve the purpose of performing contact testing and short-circuit testing on each capacitor in large-scale aging at a low cost.

Description

Technical Field

[0001] The present invention relates to the technical field of capacitor detection, and in particular to an online capacitor state testing device for batch capacitor aging. Background Art

[0002] During the batch aging of capacitors with power and heating, the elasticity of the elastic contacts will gradually weaken due to the long-term operation of the fixture at high temperature, and the contacts will gradually wear and oxidize, causing the contact resistance between the contacts and the capacitors to gradually increase, which will eventually affect the aging effect and cause the aging of the electrolytic capacitors to be a virtual aging result with insufficient power voltage or even no voltage applied. In the equipment used for the aging of large quantities of capacitors, it is necessary to add the contact test function between the above contacts and the capacitors, and at the same time, it is also necessary to identify each short-circuited capacitor that breaks down during the aging process.

[0003] There is an existing technology that uses a capacitance capacity test method to evaluate whether the fixture contacts and capacitor electrodes are in good contact. Large-scale aging equipment usually uses a fixture to connect multiple capacitors in parallel as a group, thereby greatly reducing the connection between the capacitor and the pressurized power supply. For a capacitor group in parallel, if a single capacitor has poor contact, and the total capacity change caused by it does not significantly exceed the change caused by the capacity error, it is impossible to determine whether poor contact has occurred in this group of capacitors. Even if it can be determined that there are capacitors with poor contact in this group of capacitors, it is impossible to determine which capacitor has poor contact. The only way to eliminate the hidden dangers of virtual aging is to abandon this group of capacitors.

[0004] There is another technology that provides an independent test channel for each capacitor, which can test the connection status of each capacitor. However, this requires a large number of switching devices and wires connecting the channels to the current test device, which greatly increases the cost of mass aging. Summary of the invention

[0005] An object of the present invention is to provide an online capacitor state testing device for capacitor batch aging, which can achieve the purpose of performing contact test and short circuit test on each capacitor in large batch aging at low cost.

[0006] In particular, the present invention provides an online capacitor state testing device for batch aging of capacitors, characterized in that a plurality of capacitors are arranged in a matrix formation, and each row and each column are respectively provided with a horizontal connecting line and a vertical connecting line; one end of a plurality of capacitors located in the same row is connected to the same horizontal connecting line, and the other end of a plurality of capacitors located in the same column is connected to the same vertical connecting line; a horizontal connecting line is connected to a common end of a horizontal relay, and the normally-on end of the horizontal relay is connected to a power supply; a vertical connecting line is connected to one end of a test meter, and the other end of the test meter is connected to the normally-on end of the vertical relay; in the case of capacitor aging, each horizontal relay and each vertical relay are in a normally-on state; in the case of capacitor testing, the horizontal relay connected to the capacitor to be tested is in a normally-on state, and the other horizontal relays are in a normally-off state, so that the test meter reads the current of the circuit in which the capacitor to be tested is located.

[0007] Preferably, a capacitor and a protection element are connected in series to form an aging unit, one end of multiple aging units in the same row is connected to the same horizontal connection line, and the other end of multiple aging units in the same column is connected to the same vertical connection line.

[0008] Preferably, the normally-on end of the transverse relay is connected to an external power line, the external power line is connected to a common end of a power relay, the normally-on end of the power relay is connected to a DC power supply, and the normally-open end of the power relay is connected to an AC power supply.

[0009] Preferably, the longitudinal connecting line is connected to the input end of a DC current test meter and the input end of an AC current test meter respectively, the other end of the DC current test meter is connected to the normally-on end of a longitudinal relay, and the other end of the AC current test meter is connected to the normally-open end of a longitudinal relay.

[0010] Preferably, the protection element is a protection resistor.

[0011] The capacitor status online testing device of the present invention forms a matrix of multiple capacitors, and uses multiple capacitors in the same row as an aging group and multiple capacitors in the same column as a test group. When a single capacitor needs to be tested, it is only necessary to power the row where the capacitor to be tested is located, and the circuit current of each capacitor in the row can be read out through the test table of each column.

[0012] When DC power is supplied to the row of capacitors to be tested, if an overcurrent occurs in one of the capacitors in the row, the current reading measured by the test meter will surge, thereby identifying any capacitor with overcurrent. When AC power is supplied to the row of capacitors to be tested, if the AC current reading of some of the capacitors is relatively small or even zero, it means that the capacitor has a problem of poor contact with the aging fixture.

[0013] Therefore, the present invention can measure and identify the poor contact (open circuit) and overcurrent (short circuit) states of the M×N capacitors in an M-row, N-column matrix by using only M+N test channels, N DC ammeters, and N AC ammeters during aging, thereby realizing the aging process monitoring function of a large number of capacitors at a relatively low cost.

[0014] Based on the following detailed description of specific embodiments of the present invention in conjunction with the accompanying drawings, those skilled in the art will become more aware of the above and other objects, advantages and features of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings:

[0016] Figure 1 4 is a circuit diagram of a capacitor state online testing device according to the present invention. DETAILED DESCRIPTION

[0017] The present invention proposes a method for testing the contact state between each capacitor and the fixture contact in large-scale aging, which can measure the actual contact state of each capacitor, thereby identifying and eliminating capacitors with poor contact. The number of test devices used in the entire circuit and the number of wires connected to the test devices are greatly reduced, thereby greatly reducing the cost of the entire aging equipment.

[0018] like Figure 1 As shown, the present invention adopts a method of forming a matrix of multiple capacitors. In order to maximize the number of equipment aging capacitors, this embodiment adopts Figure 1 In the figure, there are M×N capacitors arranged in a matrix of M rows and N columns. In other embodiments, multiple capacitors can also be arranged in other effective arrays, such as a triangular matrix, a mesh matrix, a star matrix, etc.

[0019] In order to ensure that each capacitor can be independently protected during the aging process, each capacitor in this embodiment is connected in series with a protection element to form an aging unit. One end of the aging unit is a capacitor end, and the other end is a protection element end. The protection element uses a protection resistor. Therefore, M×N aging units form a matrix. In other embodiments, the protection element is not necessarily provided. If a protection element is provided, it can also be a constant current diode, a current fuse, etc.

[0020] A group of capacitor ends of aging units arranged horizontally are connected with a horizontal connecting line, and a group of protection element ends of aging units arranged vertically are connected with a vertical connecting line. For example, a stepped capacitor similar to an electrolytic capacitor needs to pay attention to the capacitor direction. The capacitor ends of each aging unit are in the same direction. In this way, the capacitor end of each aging unit is connected to all the capacitor ends of all other aging units arranged horizontally to form a horizontal connecting line. In other words, the capacitor ends of multiple aging units in the same row are connected to the same horizontal connecting line. The protection element end of each aging unit is connected to all the protection element ends of other aging units arranged vertically to form a vertical connecting line. In other words, the protection element ends of multiple aging units in the same column are connected to the same vertical connecting line. Finally, multiple (M) horizontal connecting lines and multiple (N) vertical connecting lines are formed.

[0021] The present invention connects the above-mentioned M horizontal connecting wires to the common end of the M horizontal relay selection switches. All the normally-on ends of the horizontal relays are connected to the external power line, and all the normally-off ends are connected to the ground. The function of the M horizontal relays is to select one or several of the M wires of all the aging units to be connected to the power line or to the ground.

[0022] The above external power line is connected to the common end of the power relay switch. The normally-on end of the power relay is connected to the positive end of a DC power supply, and the normally-off end of the power relay is connected to the output end of an AC power supply. The low output ends of the two power supplies are connected to the ground. The power relay can choose to connect one or several aging units in the same line to a DC power supply or to an AC power supply.

[0023] The N longitudinal connecting wires are respectively connected to the current input terminals of N DC current test meters (modules) and N AC current test meters (modules). The other terminals of the N DC ammeters are respectively connected to the normally open terminals of the N longitudinal relay selection switches, and the other terminals of the N AC ammeters are respectively connected to the normally open terminals of the same N longitudinal relays, and the common terminals of the longitudinal relays are connected to the ground. The function of the N longitudinal relays is to select a certain aging unit to be connected to the DC ammeter or to the AC current ammeter.

[0024] In the normal aging process, each horizontal relay and each vertical relay are in the normally on state, and all aging units are connected to the DC power supply and are in the aging mode. At this time, all N vertical connecting wires are connected to N DC ammeters, and each DC ammeter reads the parallel leakage current of the M capacitors in the connected vertical connecting wire.

[0025] During the aging process, if the single capacitor test mode is started, by controlling M horizontal relays, only one horizontal connection line in the row where the capacitor to be tested is connected to the external power line, and the remaining horizontal connection lines are connected to the ground. At this time, you can also choose to test the DC current or the AC current. If you choose to test the DC current, the power line is still connected to the DC power supply, and the ammeter is still connected to N DC ammeters. At this time, the N DC ammeters measure the independent leakage current of all N capacitors connected in this horizontal connection line. If an overcurrent occurs in one of the capacitors, the measured current will surge, so that any capacitor with overcurrent can be identified.

[0026] When testing AC current, the power cord is connected to the AC power supply, and the ammeter is connected to N AC ammeters. At this time, the N AC ammeters measure the AC current of all N capacitors connected in this horizontal connecting line. When the AC current of some capacitors is relatively small or even zero, it means that the capacitor has a poor contact with the aging fixture.

[0027] In summary, the present invention can measure and identify the poor contact (open circuit) and overcurrent (short circuit) states of M×N capacitors in an M-row, N-column matrix by using only M+N test channels, N DC ammeters, and N AC ammeters during aging, thereby realizing the aging process monitoring function of a large number of capacitors at a relatively low cost.

[0028] At this point, those skilled in the art should recognize that, although multiple exemplary embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived based on the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and recognized as covering all these other variations or modifications.

Claims

1. A capacitor state online testing device for capacitor batch aging, characterized in that: A plurality of capacitors are arranged in a matrix formation, and each row and each column are respectively provided with a horizontal connecting line and a vertical connecting line; one end of the plurality of capacitors in the same row is connected to the same horizontal connecting line, and the other end of the plurality of capacitors in the same column is connected to the same vertical connecting line; a horizontal connecting line is connected to a common end of a horizontal relay, and a normally-on end of the horizontal relay is connected to a power supply; a vertical connecting line is connected to one end of a test meter, and the other end of the test meter is connected to the normally-on end of the vertical relay; in the case of capacitor aging, each horizontal relay and each vertical relay are in a normally-on state; in the case of capacitor testing, the horizontal relay connected to the capacitor to be tested is in a normally-on state, and the other horizontal relays are in a normally-off state, so that the test meter reads the current of the circuit where the capacitor to be tested is located; A capacitor and a protection element are connected in series to form an aging unit, one end of multiple aging units in the same row is connected to the same horizontal connection line, and the other ends of multiple aging units in the same column are connected to the same vertical connection line; The normally-on end of the transverse relay is connected to an external power line, the external power line is connected to a common end of a power relay, the normally-on end of the power relay is connected to a DC power supply, and the normally-open end of the power relay is connected to an AC power supply; The protection element is a protection resistor.

Images