CN207623447U - A current transformer polarity testing device - Google Patents

Abstract

The utility model relates to a current transformer polarity test device belongs to electric power system test equipment technical field. A polarity testing device for a current transformer comprises a single chip microcomputer control system for generating pulse signals, a power amplifier and a universal meter; the output end of the single chip microcomputer control system is connected with the input end of the power amplifier, the output end of the power amplifier is connected to two ends of a wire of the primary device through which the current transformer penetrates, and the universal meter is connected with two ends of a secondary outgoing line of the current transformer. The utility model uses the single chip microcomputer control system or the dry battery control circuit to automatically generate the pulse signal to enable the current transformer to generate induction current, and the polarity of the current transformer is judged by the deviation of the pointer of the universal meter, the device has simple operation and high automation degree; the device can ensure the accuracy of the test, greatly reduce the labor intensity of workers, correspondingly reduce the test time, improve the test efficiency and ensure that the test accuracy can reach 100 percent.

Description

A current transformer polarity testing device

technical field

The utility model relates to a polarity testing device for a current transformer, which belongs to the technical field of power system testing equipment.

Background technique

Current transformer (CT) is an important electrical equipment in the power system. It is responsible for the isolation between high and low voltage systems and the conversion of high voltage to low voltage. Whether the wiring is correct or not is of great significance to the normal operation of the protection, measurement, metering and other equipment of the system. When the newly installed current transformer is put into operation or the secondary cable of the current transformer is replaced, using the polarity test method to check the correctness of the current transformer wiring is already an indispensable work procedure for relay protection workers.

The usual way to check the wiring of the current transformer is to first connect the negative pole of the dry battery to one end of the wire of the primary equipment through which the current transformer passes, and then use the positive pole of the dry battery to touch the other end of the wire of the primary equipment for 1 to 2 seconds. , so that a positive pulse current is generated in the wire of the primary equipment of the current transformer in a short period of time, and an induced current will be generated on the secondary side of the current transformer. Another person makes observational measurements through the meter. Although the parts used in this test method are simple, because the pulse current is generated by manual operation of the dry battery, it has good requirements for the operation and requires the cooperation of two people to complete it. The test results are closely related to various factors such as the operator's technical level, mental state and professionalism. This method is time-consuming and laborious, and the accuracy is not high.

Utility model content

The purpose of the utility model is to provide a current transformer polarity test device which can improve the automation degree of the current transformer polarity test, and improve the test efficiency and accuracy.

In order to achieve the above object, the technical solution adopted by the utility model is:

A current transformer polarity test device, including a control system for generating pulse signals and a multimeter; the output end of the control system is connected to the two ends of the wires of the primary equipment that the current transformer passes through, and the multimeter is connected to the secondary of the current transformer. out both ends.

The further improvement of the technical solution of the utility model lies in that the control system is a single-chip microcomputer control system.

The further improvement of the technical solution of the utility model is: the single-chip microcomputer control system includes a single-chip microcomputer and a power amplifier; the output end of the single-chip microcomputer is connected with the input end of the power amplifier, and the output end of the power amplifier is connected to the two ends of the wires of the primary equipment that the current transformer passes through , Connect the multimeter to both ends of the secondary outlet of the current transformer.

The further improvement of the technical solution of the utility model lies in that: the amplification factor of the power amplifier is 100 times.

The further improvement of the technical solution of the utility model is that: the control system is a dry battery control circuit, in which a dry battery, a circuit switch, and a cycle delay time relay are sequentially connected in series, and the output end of the dry battery control circuit is connected to a current transformer The two ends of the wire of the primary equipment passing through; the multimeter is connected to the two ends of the secondary outlet of the current transformer.

The further improvement of the technical solution of the utility model lies in that the pulse signal is a rectangular pulse signal.

The further improvement of the technical solution of the utility model lies in that: the period of the rectangular pulse signal is 5s, and the pulse is 1s.

Owing to adopting above-mentioned technical scheme, the technical effect that the utility model obtains has:

The utility model uses a single-chip microcomputer control system to generate a pulse signal to cause the current transformer to generate an induced current. Compared with the traditional method, only one person is needed to complete the test operation, which can reduce the amount of labor on site and save manpower. At the same time, the labor intensity of the staff is greatly reduced, the test time is also greatly reduced, and the test efficiency is greatly improved.

The utility model uses a power amplifier to amplify the pulse signal generated by the single-chip control system, so that the induced current in the current transformer can be measured by the multimeter, and the power amplifier ensures that the polarity of the current transformer can be measured by using the single-chip control system to generate the pulse signal. Successful implementation.

The utility model uses a single-chip microcomputer control system to generate a pulse signal to make the current transformer generate an induced current, and judges the polarity of the current transformer through the pointer deflection of the multimeter, which is easy to operate and can ensure the accuracy of the test, and the test accuracy can reach 100. %.

In the utility model, a cycle delay time relay is connected in series in the dry battery control circuit, so that the dry battery control circuit can automatically generate a pulse signal, thereby realizing automatic testing of the polarity of the current transformer.

The utility model has simple operation and high degree of automation.

Description of drawings

Fig. 1 is a schematic diagram of the connection of each part when the utility model uses a single-chip microcomputer control system;

Fig. 2 is a schematic diagram of the connection of each component when the utility model uses the dry battery control circuit;

Among them, 1. Single-chip microcomputer, 2. Power amplifier, 3. Current transformer, 4. Multimeter, 5. Lead wire of primary equipment, 6. Secondary outlet, 7. Dry battery, 8. Circuit switch, 9. Cycle delay time relay , 10. Protective device.

detailed description

Below in conjunction with accompanying drawing and specific embodiment the utility model is described in further detail:

The utility model discloses a polarity testing device for a current transformer, which is used for testing the polarity of the current transformer, and then operating and maintaining a power system. The following are specific examples:

The current transformer 3 has a primary side and a secondary side. As shown in Figure 1, the wire 5 of the primary equipment in the circuit is set around the primary side of the current transformer 3, and the secondary outlet 6 in the circuit is surrounded by the secondary side of the current transformer. side setting.

The control system of the utility model has two setting modes, one is a single-chip microcomputer control system composed of a single-chip microcomputer 1 and a power amplifier 2; the other is a dry battery control circuit composed of a dry battery and a cycle delay relay.

Example 1:

Summarized in this embodiment, the utility model uses a single-chip microcomputer control system composed of a single-chip microcomputer 1 and a power amplifier 2, as shown in FIG. 1 , including a single-chip microcomputer 1, a power amplifier 2 and a multimeter 4. The single-chip microcomputer 1 is used to generate a stable pulse signal in the test device. The output terminal of the single-chip microcomputer 1 is connected to the input terminal of the power amplifier 2, and the output terminal of the power amplifier 2 is connected to the wire of the primary equipment that the current transformer 3 passes through. 5, specifically, the output end of the power amplifier 2 is connected to both ends of the wire 5 of the primary device through which the current transformer 3 passes through a wire. A multimeter 4 is connected to both ends of the secondary outgoing line 6 of the current transformer 3 , and the multimeter 4 is used to detect the direction of the induced current at the secondary side of the current transformer 3 . Multimeter 4 uses an analog multimeter. The amplification factor of the power amplifier 2 is usually 100 times.

When in use, the pulse signal generated by the single-chip microcomputer 1 is amplified by the power amplifier 2 and then loaded to the primary side of the current transformer 3, and the secondary side of the corresponding current transformer 3 generates an induced current; the pointer of the multimeter 4 acts on the induced current. The deflection occurs below, and the polarity of the current transformer can be judged by the deflection direction of the pointer of the multimeter 4. When testing, turn the function selection knob of the multimeter 4 to DC voltage. The utility model judges the polarity of the current transformer through the pointer deflection of the multimeter, which is convenient and intuitive. The utility model uses a power amplifier to amplify the pulse signal generated by the single-chip microcomputer control system, and the amplified pulse signal is input into the wire of the primary device of the current transformer, and then the secondary side of the current transformer generates an induced current that can be measured by the multimeter. The power amplifier ensures that the polarity measurement of the current transformer can be successfully implemented by using the single-chip microcomputer control system to generate pulse signals. Selecting the appropriate power amplifier in the specific implementation can ensure the safety of the multimeter.

The judgment method when using the utility model to test the polarity of the current transformer is that if the gauge needle of the multimeter deviates from 0 from left to right, both the gauge needle is positively opened, indicating that the primary input terminal of the connected current transformer 3 is positively connected to the multimeter. The secondary output terminal of the current transformer connected to the binding post is the terminal with the same name, and the two polarities are the same; if the needle of the multimeter shifts from 0 from right to left, that is, the needle reverses, indicating that the primary input terminal of the current transformer connected The secondary output terminal of the current transformer connected to the positive terminal of the multimeter is not the terminal with the same name, and the polarity of the two is opposite. When using the device to test the polarity of the current transformer, only one tester is needed, and the tester turns on the single-chip microcomputer control system and observes the pointer of the multimeter.

In the specific use process, adjust the single-chip microcomputer 1 to make it send out a rectangular pulse signal with a fixed time interval. In order to ensure the safety of the instrument and ensure the measurement accuracy, the period of the rectangular pulse signal is set to 5s, and the pulse is 1s. The use of shorter pulses can ensure the safety of the multimeter. Even if the pointer of the multimeter deflects to the left, the pulse duration is short and the multimeter will not be damaged.

It is also possible to use a pointer ammeter in the utility model, even if a pointer ammeter is used instead of a pointer universal meter, the same test effect can be achieved.

Example 2:

In this embodiment, the utility model uses a dry battery control circuit composed of a dry battery and a cycle delay relay as the control system. All three-phase lines are shown in the drawings of this embodiment, and the circuit for testing the single-phase lines is schematically shown in FIG. 2 . After the dry battery 7, the cycle delay time relay 9, and the circuit switch 8 form a series circuit, the two ends of the circuit are connected as output ends to the two ends of the wire 5 of the primary device through which the current transformer 3 passes. One end of the secondary outlet 6 is connected to a meter for testing, which can be a pointer ammeter or a pointer multimeter. A protection device 10 is also connected to the end of the secondary outlet line 6 . When using, first set the delay time of the cycle delay time relay. For example, it can be set to the working state of closing for 1s, opening for 4s, and then closing and cycling in turn; then close the circuit switch. At this time, the dry battery control circuit capable of generating pulse signals. In this embodiment, the use process of the device is similar to that in Embodiment 1, except that the setting of the rectangular pulse signal is carried out on the cycle delay time relay.

The utility model uses a single-chip microcomputer control system to generate a pulse signal to make the current transformer generate an induced current. Compared with the traditional method, only one person is needed to complete the test operation, the labor intensity of the staff is greatly reduced, and the test time is also greatly reduced. The test efficiency is improved. Greatly improve.

The utility model uses a single-chip microcomputer control system to generate a pulse signal to make the current transformer generate an induced current, and judges the polarity of the current transformer through the pointer deflection of the multimeter, which is easy to operate and can ensure the accuracy of the test, and the test accuracy can reach 100. %.

In the utility model, a cycle delay time relay is connected in series in the dry battery control circuit, so that the pulse signal can be automatically generated in the dry battery control circuit, thereby realizing automatic testing of the polarity of the current transformer.

The utility model has the advantages of simple structure, convenient operation, high degree of automation and good performance.

Claims (7)

1. A current transformer polarity test device, characterized in that: it includes a control system for generating pulse signals and a multimeter (4); the output end of the control system is connected to the primary device that the current transformer (3) passes through Connect the two ends of the wire (5) to the two ends of the secondary outlet (6) of the current transformer (3) with the multimeter (4). 2. A current transformer polarity testing device according to claim 1, characterized in that the control system is a single-chip microcomputer control system. 3. A current transformer polarity test device according to claim 2, characterized in that: the single-chip microcomputer control system includes a single-chip microcomputer (1) and a power amplifier; the output of the single-chip microcomputer (1) and the input of the power amplifier (2) The output terminal of the power amplifier (2) is connected to both ends of the wire (5) of the primary equipment passing through the current transformer (3), and the multimeter (4) is connected to the secondary outlet wire (6) of the current transformer (3). ends. 4. A current transformer polarity testing device according to claim 3, characterized in that: the amplification factor of the power amplifier (2) is 100 times. 5. A current transformer polarity test device according to claim 1, characterized in that: the control system is a dry battery control circuit, in which a dry battery (7), a circuit switch (8 ), the cycle delay time relay (9), the output terminal of the dry battery control circuit is connected to the two ends of the wire (5) of the primary equipment through which the current transformer (3) passes; the multimeter (4) is connected to the current transformer (3) Both ends of the secondary outgoing line (6). 6. A current transformer polarity testing device according to any one of claims 1-5, characterized in that the pulse signal is a rectangular pulse signal. 7. A current transformer polarity testing device according to claim 6, characterized in that: the period of the rectangular pulse signal is 5s, and the pulse is 1s.