CN203552926U - Electronic current transformer for disconnecting circuit breaker - Google Patents

Abstract

The utility model discloses an electronic current transformer for an isolation circuit breaker, which comprises an air-core coil, an energy-taking coil, a low-power coil, a remote module, an optical cable and a suspension insulator, wherein the remote modules are respectively connected to the air-core coil and the output end of the low-power coil; the working power of the remote module is provided by the energy-taking coil or an external laser; the remote module is also connected to an optical cable, and the output digital signal is transmitted by the optical cable, and the optical cable passes through the type insulators. This kind of electronic current transformer can be integrated with 66kV～750kV isolation circuit breaker.

Description

Electronic current transformer for isolating circuit breaker

technical field

The utility model belongs to the field of high-voltage electrical appliances for power transmission and transformation equipment, in particular to an electronic current transformer that can be used for 66kV-750kV isolation circuit breakers, and can be used as a transformer in substations with voltage levels of 66kV, 110kV, 220kV, 330kV, 500kV and 750kV. Energy metering, relay protection and power monitoring.

Background technique

The disconnecting circuit breaker (DCB) is a new type of high-voltage switchgear that combines the switch and the isolation function. It can directly replace the traditional circuit breaker (CB)/disconnector (DS) combined solution, and has the advantages of small footprint and low failure rate. Low efficiency, low maintenance, low construction investment, low power outage and low maintenance cost. The electronic current transformer has the characteristics of simple insulation structure, small size, large dynamic range, and no magnetic saturation. It is a substitute for conventional electromagnetic current transformers.

Existing power transformers for substations (including electromagnetic transformers and electronic transformers) are designed and applied for traditional circuit breaker/disconnector combinations. With the construction of smart substations and the wide application of isolating circuit breakers , the existing transformers can no longer meet the requirements. It is based on this consideration that this case arose.

Utility model content

The purpose of this utility model is to provide an electronic current transformer for an isolation circuit breaker, which can be integrated with a 66kV-750kV isolation circuit breaker.

In order to achieve the above object, the solution of the present utility model is:

An electronic current transformer for an isolated circuit breaker, comprising an air-core coil, an energy-taking coil, a low-power coil, a remote module, an optical cable, and a suspension insulator, wherein the remote module is connected to the air-core coil and the low-power coil respectively The output end of the remote module; the working power of the remote module is provided by the energy-taking coil or an external laser; the remote module is also connected to an optical cable, and the output digital signal is transmitted by the optical cable, and the optical cable passes through the suspension insulator.

The above-mentioned current transformer also includes a coil housing and a remote module box both arranged on the high-voltage side, the air-core coil, the energy-taking coil and the low-power coil are respectively fixed in the coil housing, and the center of the coil housing is used for Pass through the primary current conductor of the isolation circuit breaker, and the remote module is fixed in the remote module box.

After adopting the above scheme, the utility model solves the problem that there is no current transformer that can be integrated with the isolation circuit breaker and adapt to the development needs of the new generation of intelligent substations. The electronic current transformer for the isolation circuit breaker of the utility model has a structure Simple, advanced technology, high precision, good temperature stability, high reliability and other advantages, to meet the technical development needs of the new generation of intelligent substation. The utility model has the following characteristics:

(1) The utility model can be easily integrated with the isolation circuit breaker in actual use. The primary current conductor of the isolation circuit breaker passes through the center of the coil shell of the transformer, which is easy to install, small in size and light in weight. Advanced and reliable technology;

(2) Use the air-core coil and the low-power coil to sense the current signal for protection and the current signal for measurement, so that the measurement accuracy of the current transformer is high (meeting the requirements of 0.2S level), and the temperature stability is good (can be controlled at -40°C ~+75°C temperature range to work normally) and has a large dynamic range and good transient characteristics, which can meet the needs of relay protection and electric energy measurement at the same time;

(3) Use the remote module to collect the analog output of the current sensor on the spot, and output the signal with optical fiber, and the suspended optical fiber insulator ensures insulation, simple structure and process, low cost, small volume and weight, stable insulation performance, and insulation margin Large, no flammable and explosive hidden dangers, greatly improving the safety and reliability of the power grid;

(4) The working power of the remote module can be provided by the energy-taking coil or an external laser. When the primary current is less than a certain value, the working power of the remote module is provided by the external laser through the optical cable. When the primary current is greater than this fixed value, the remote The working power of the module is provided by the energy-taking coil, and the two power supply modes can realize seamless switching;

(5) In actual use, dual redundant configurations can be made according to requirements, including air-core coils, low-power coils, energy-taking coils, and remote modules, which can be configured as two independent sets of each other. If a set of sensors or remote modules fail It will not affect the normal operation of another set of sensors or remote modules, and the dual sampling and comparison technology is used for the analog signal output by each sensor to compare and verify the sampling values of the two channels in real time, so as to realize the hardware self-test function of the sampling loop and avoid The problem of protection malfunction caused by abnormal sampling is solved, and the reliability is high.

Description of drawings

Fig. 1 is the structural representation of the utility model;

Fig. 2 is a schematic diagram of the integrated structure of the utility model and the isolation circuit breaker.

Detailed ways

The technical solutions and beneficial effects of the present utility model will be described in detail below in conjunction with the accompanying drawings.

As shown in Figure 1, the utility model provides an electronic current transformer for an isolation circuit breaker, which can be used in conjunction with a 66kV, 110kV, 220kV, 330kV, 500kV or 750kV isolation circuit breaker. The current transformer includes a coil housing 1 , an air-core coil 2, an energy-taking coil 3, a low-power coil 4, a remote module 5, a remote module box 6, an optical cable 7 and a suspension insulator 8, wherein the coil housing 1 and the remote module box 6 are both Set on the high-voltage side, the coil housing 1 is fixed with an air-core coil 2, an energy-taking coil 3 and a low-power coil 4, and the center of the coil housing 1 is used to pass through the primary current conductor of the isolation circuit breaker, wherein, The air-core coil 2 is used for sensing the current signal for protection, and the low-power coil 4 is used for sensing the current signal for measurement.

A remote module 5 is fixed in the remote module box 6, and the remote module 5 is respectively connected to the output ends of the air-core coil 2 and the low-power coil 4, and the output signals of the two are collected and processed on the spot, and the hardware integration technology is used to Integral transformation is performed on the differential signal output by the air-core coil 2, so that the current transformer has higher measurement accuracy, larger dynamic range and better transient characteristics; Design two independent sampling loops to complete dual sampling. Real-time comparison and verification of two-way sampling values realizes the hardware self-check function of the sampling loop, and avoids protection malfunctions caused by abnormal sampling; the working power of the remote module 5 can be provided by the energy-taking coil 3 or an external laser. At a certain value, the working power of the remote module 5 is provided by an external laser through the optical cable 7. When the primary current is greater than this fixed value, the working power of the remote module 5 is provided by the energy-taking coil 3. The two power supply methods can realize seamless switching .

The remote module 5 is also connected to an optical cable 7 , and the output digital signal is transmitted by the optical cable 7 , and the optical cable 7 passes through a suspension insulator 8 , which is used to isolate high and low potentials and protect the optical cable 7 .

In actual implementation, the air-core coil 2, the low-power coil 4 and the remote module 5 can be configured with dual redundancy according to engineering requirements. The two sets of configurations work independently and serve as backups for each other. One set works normally, thus ensuring the reliability of the current transformer.

As shown in Figure 2, when the utility model is integrated with the isolating circuit breaker, the coil housing 1 is fixed in the middle of the isolating circuit breaker 9, and the measured current flowing through the isolating circuit breaker 9 flows through the middle of the coil housing 1 at the same time . The coil shell 1 is fixed with an air-core coil 2, an energy-taking coil 3 and a low-power coil 4, and the remote module 5 is fixed inside the remote module box 6. The air-core coil 2 senses the current signal for protection, and the low-power coil 4 Sensing the current signal for measurement, the remote module 5 collects the output signals of the air-core coil 2 and the low-power coil 4 at the same time, and the working power of the remote module 5 is provided by an external laser or provided by the energy harvesting coil 3 from the primary current induction energy . The output signal of the remote module 5 is transmitted through the optical cable 7, and the optical cable 7 passes through the suspension insulator 8, and the suspension insulator 8 is used for high and low voltage isolation and protection of the optical cable 7.

The above embodiments are only to illustrate the technical ideas of the utility model, and cannot limit the protection scope of the utility model with this. Any changes made on the basis of the technical solutions according to the technical ideas proposed by the utility model all fall into the scope of the utility model. within the scope of the new protection.

Claims (2)

1. an isolation circuit breakers electronic current mutual inductor, it is characterized in that: comprise hollow coil, get energy coil, low-power coil, remote end module, optical cable and suspension insulator, wherein, described remote end module connects respectively the output of hollow coil and low-power coil; The working power of described remote end module is provided by the laser of getting energy coil or outside; Described remote end module also connects optical cable, and the digital signal of output is transmitted by optical cable, and described optical cable is through suspension insulator.

2. a kind of isolation circuit breakers electronic current mutual inductor as claimed in claim 1, it is characterized in that: described current transformer also comprises and is all arranged on high-tension side solenoid housing and remote end module casing, described hollow coil, get can coil and low-power coil be separately fixed in solenoid housing, and the center of solenoid housing is for the once through-flow conductor through isolation circuit breakers, and remote end module is fixed in remote end module casing.

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