CN201956187U - Electronic voltage transformer - Google Patents

Abstract

Provided is an electronic type voltage transformer. A weak magnetic coupling sensing component is arranged a casting body, two terminals of the primary winding of the sensing component are respectively connected to a primary binding post and a grounding terminal that are arranged on the casting body, and the secondary winding of the sensing component is serially connected to a senseless resistive component; the output end of the secondary signal of the sensing component is connected to a secondary binding post after the secondary signal of the sensing component is adjusted by the senseless resistive component, and the primary winding and the secondary winding of the sensing component are respectively provided with a segment average voltage and a layered shield. The electronic type voltage transformer in the utility model has the advantages of high accuracy grade, good stability and anti-EMI through weak magnetic coupling, by selecting resistive resistance with low temperature drift as the component and taking the comprehensive measures of average voltage and shielding on electric field.

Description

Electronic voltage transformer

technical field

The utility model patent relates to an electrical component, which is an electronic voltage transformer that converts high voltage in the power system into a low voltage with a certain value to supply the metering, measurement and relay protection of the power system.

Background technique

In the power system, the signals required for voltage metering, measurement and relay protection are mostly provided by electromagnetic transformers. The problems of this transformer are short circuit risk, heavy weight, large volume, and secondary load reflection. Sensitive, prone to ferromagnetic resonance, serious safety hazards will occur. At present, with the continuous development of intelligent technology, the power system has developed towards networking, automation and digitalization, and the input signals required by secondary equipment have been significantly reduced, and large-capacity secondary signals are not required. Therefore, this traditional It is difficult for electromagnetic voltage transformers to meet new technical requirements. There is an urgent need for an electronic transformer with no risk of short circuit, small size, light weight, insensitivity to secondary loads, stable performance, and good linearity.

With the development of digital substations and the needs of smart grid construction, power systems have higher and higher requirements for intelligence and automation of measurement, protection, control and data transmission, and electronic voltage transformers that have emerged as a result have become popular. The research object, in the current medium voltage system, most of the electronic voltage transformers adopt the principle of resistance voltage division and the principle of resistance-capacity voltage division. The structure is complex (resistance-capacitance division requires an external power supply), and the accuracy is low. Especially after a period of operation, the error data deviates seriously, exceeding the accuracy level data at the factory, and failing to meet the actual requirements of users.

Utility model content

The purpose of this utility model is to provide an electronic voltage transformer with high measurement accuracy, good linearity, stable performance and no risk of short circuit.

The technical scheme that the technical problem that the utility model solves adopts is:

An electronic voltage transformer, which is characterized in that a weakly magnetically coupled sensor is provided in the cast body, and the two terminals of the primary winding of the sensor are respectively connected to the primary terminal (high voltage terminal A) on the cast body. It is connected with the grounding terminal (grounding terminal N). The secondary winding of the sensor is connected in series with or without inductive resistive elements. Part of the non-inductive resistive element is directly set in the casting body, and a part is set in the adjustment box with shielding function. inside. After the secondary signal of the sensor is adjusted by the non-inductive resistive element, the output terminal is connected to the secondary terminal. The primary winding and secondary winding of the sensor are respectively equipped with measures such as segmental voltage equalization and layered shielding.

The primary winding of the sensing element is evenly wound on the insulating frame, and the two ends of the primary winding are respectively connected with the primary connection terminal and the grounding terminal embedded in the casting body.

The primary connection terminal and grounding terminal are connectors with internal threads, which are respectively embedded in the upper and lower parts of the cast body of the transformer.

The secondary winding of the sensing element is evenly wound on the insulating frame coaxial with the primary winding, and the primary winding and the secondary winding are insulated and isolated by organic insulating materials, and the secondary winding is connected to a non-inductive resistive element. Connect with the secondary terminal.

The non-inductive resistive element is a group of resistors, which are connected in series with the secondary winding of the sensing element. The part of the resistor with low temperature drift is directly set in the casting body, and the other part of the resistor is installed in the shielding function. Adjustment box. These non-inductive resistive elements have the characteristics of wide ambient temperature range, high precision, small temperature coefficient and good stability.

The secondary signal of the sensing part is transformed by the non-inductive resistive element, and the output end is connected with the secondary terminal with a shielded wire.

The outer shielding cable is connected to the secondary terminal, and the other end of the outer shielding cable has a connector for easy connection. The end of the adjustment box is connected to the shielding layer of the secondary terminal through the shielded wire outer network.

The segmental voltage equalization is to set a potential ring on the primary winding of the sensing element according to an equal potential difference.

The layered shielding is a step-by-step wrapping of different conductors on the secondary winding of the sensor. The weak magnetic coupling sensor is an assembly with a primary winding, a secondary winding and a small iron core.

The electronic voltage transformer of the utility model adopts the principle of combining weak magnetic coupling sensing and low-temperature drift alloy resistance sampling, so that the designed product not only has no short circuit risk, light weight, small volume, wide linear area, etc. The characteristics of electronic products, and the product has stable performance, strong load capacity (above 1,000 ohms), no external power supply, simple structure, and easy installation.

The utility model improved by this technology is a new combination based on the conversion principle of weak magnetic coupling and non-inductive resistive resistance elements. Through the connection of weak magnetic coupling sensing parts and non-inductive resistive elements, the high voltage of the transmission network can It is a low voltage that meets various functional requirements of intelligence and digitization and is directly proportional to it, and this low voltage signal has the characteristics of high precision, good linearity, stable performance, and no short circuit risk. Thereby replacing the traditional electromagnetic voltage transformer. Because the voltage transformer has no short-circuit danger in the whole measurement range, the input and output linearity is good, and the performance is stable, so it can greatly improve the measurement accuracy and reliability when used in conjunction with the intelligent secondary unit. The technical improvement utility model is an innovative combination design of the weak magnetic coupling sensing element and the non-inductive resistive resistance conversion element, so that the product has high measurement accuracy, good linearity, stable performance, and no short circuit danger. New technical effects that can meet the needs of intelligent secondary equipment. The primary winding of the sensor is evenly wound on the insulating skeleton, and the two ends of the winding are respectively connected to the primary terminal embedded in the upper and lower parts of the casting body and the grounding insert. Concept set potential ring. The secondary winding of the sensor is evenly set in the insulating frame and is isolated from the primary winding through organic insulation. The secondary winding is connected to the secondary terminal after being connected in series with a non-inductive resistive element. The non-inductive resistive components are installed in the adjustment box with shielding function, and the connections between the non-inductive resistive components and the secondary winding, secondary terminals, and adjustment box are all connected by shielded wires. Through the above measures, a good shielding effect can be formed. Improve its anti-interference ability. The electronic voltage transformer uses organic insulating materials to cast the above-mentioned sensing parts, non-inductive resistive elements, terminal blocks, adjustment boxes, shielded wiring, etc. into one body, and has good insulation and mechanical properties. The outline of the casting body is rectangular, with the primary high-voltage terminal on the upper part, the primary grounding terminal and the secondary terminal on the lower part, and the secondary terminal has a connector for easy connection with the intelligent secondary unit. .

The characteristics of this technology improved utility model:

The beneficial effects of the utility model are:

(1) High precision, good linearity and stable performance;

(2) There is no dangerous phenomenon of short circuit and large current, and its operation is safe and reliable;

(3) It has complete functions and is easy to use, and can be used as a sensing component for measurement and protection of electronic systems;

(4) Small size and light weight;

(5) Low cost and low energy consumption in operation;

(6) No noise, anti-interference, and superior environmental protection characteristics;

The utility model can meet the needs of the metering, measurement and protection of the electric power system in the direction of digitization, intelligence and networking.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is a schematic structural view of an embodiment of the utility model.

In the figure: 1. Primary terminal 2. Primary winding 3. Secondary winding 4. Primary end connection 5. Skeleton 6. Grounding insert 7. Adjustment box 8. Non-inductive resistive element I 9. Secondary side connection I 10. Secondary terminal 11. Non-inductive resistive element II 12. Layered shielding 13. Secondary side connection II 14. Epoxy resin 15. Segmented voltage equalizing ring

Detailed ways

Below according to shown in Figure 1, the utility model embodiment is stated:

As shown in Figure 1, the electronic voltage transformer uses a weakly coupled sensing element, the primary winding 2 of the sensing element is evenly wound on the insulating skeleton 5, and the two ends of the primary winding 2 are respectively connected to the ring The primary connection terminal 1 on the upper and lower parts of the pouring body of the epoxy resin 14 is connected to the grounding insert 6 , and the primary connection terminal 1 and the grounding insert 6 are connectors with internal threads, that is, connection nuts. The secondary winding 3 is nested on the skeleton 5, and the primary side is isolated from the secondary side by organic insulation, so that the high voltage of the primary side is completely isolated from the low voltage of the secondary side, which plays the role of safety insulation. The secondary winding 3 is connected to the secondary terminal 10 after the non-inductive resistive element I 8 and the non-inductive resistive element II 11. The non-inductive resistive element II 11 is directly arranged in the pouring body, and the non-inductive resistive element I 8 is installed in the adjustment box 7 with shielding function. The primary winding 2 of the sensor is provided with a segmented voltage equalizing ring 15 , and the secondary winding 3 is provided with a layered shield 12 . The connecting wire 4 at the primary end of the sensing element and all the connecting wires I 9 and II 13 of the secondary side are transition-connected with shielded wires. A shielded cable with a certain length and a connector at one end is connected to the secondary terminal 10, so that it can be easily connected with external equipment. The electrical components of the whole product are cast into one body with epoxy resin 14 .

Due to the weak magnetic coupling in the design of the transformer, the use of low-temperature drift resistive resistors in the selection of components, and the use of comprehensive measures such as voltage equalization and shielding in the electric field treatment, the electronic transformer has high accuracy, good stability, Anti-electromagnetic interference and other advantages.

Claims (11)

1. electronic type voltage transformer, it is characterized in that in pour mass, being provided with the sensing part of a weak magnetic coupling, two terminals of winding of sensing part respectively be located at pour mass on the primary connection terminal be connected with earth terminal, the secondary winding of sensing part is serially connected with noninductive resistance element; Sensing part secondary singal output after noninductive resistance element adjustment is connected with the secondary connection terminal, and winding of sensing part and secondary winding are respectively equipped with that segmentation is all pressed, laminated shield.

2. electronic type voltage transformer according to claim 1 is characterized in that a winding is wound on the skeleton of insulation equably, and the two ends of a winding are connected with earth terminal with the primary connection terminal that is embedded in pour mass respectively.

3. electronic type voltage transformer according to claim 1 and 2 is characterized in that primary connection terminal and earth terminal are the connector that has internal thread, and it is embedded in the upper and lower of instrument transformer pour mass respectively.

4. electronic type voltage transformer according to claim 1, it is characterized in that secondary winding be wound on equably with the coaxial insulation framework of winding on, and winding and secondary winding are by the organic insulating material isolation of insulating, and secondary winding is connected with the secondary connection terminal after connecting noninductive resistance element.

5. according to claim 1 or 4 described electronic type voltage transformers, it is characterized in that described noninductive resistance element is one group of resistance, it is connected in series with the secondary winding of sensing part, have this part resistance that low temperature floats and be set directly in the pour mass, another part resistance is contained in the adjustment box with function of shielding.

6. according to claim 1 or 4 described electronic type voltage transformers, it is characterized in that the sensing part secondary singal is connected with the secondary terminal with shielding wire through noninductive resistance element conversion output.

7. according to claim 1 or 4 described electronic type voltage transformers, it is characterized in that being connected with the external shield cable on the described secondary connection terminal, the other end of external shield cable has the connector that can conveniently connect.

8. electronic type voltage transformer according to claim 5 is characterized in that described adjustment box end is connected through the screen of shielding wire outer net with the secondary terminal.

9. electronic type voltage transformer according to claim 1 is characterized in that described segmentation all presses to by the equipotential difference current potential ring is set on a winding of sensing part.

10. electronic type voltage transformer according to claim 1 is characterized in that described laminated shield is the wrapping of carrying out with different conductors on the secondary winding of sensing part step by step.

11. electronic type voltage transformer according to claim 1 is characterized in that described weak magnetic coupling sensing part is an assembly that has winding, secondary winding, little iron core.

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