CN210865891U

CN210865891U - Zero-flux high-precision current transformer

Info

Publication number: CN210865891U
Application number: CN202020077566.5U
Authority: CN
Inventors: 曾琴; 杨博
Original assignee: Shenzhen Zhicheng Electric Measurement Technology Co ltd
Current assignee: Shenzhen Zhicheng Electric Measurement Technology Co ltd
Priority date: 2020-01-14
Filing date: 2020-01-14
Publication date: 2020-06-26
Anticipated expiration: 2030-01-14

Abstract

The utility model discloses a zero magnetic flux high accuracy current transformer, including main body cover, compensating coil base, be provided with current transformer among the main body cover, the main body cover surface sets up load interface, this load interface with current transformer electric connection, set up compensating coil and be used for twining this compensating coil's iron core in the compensating coil base. The utility model discloses applicable occasion such as commercial power detection, household power consumption detect, adopt the design of punching the formula, current transformer can adopt prior art, for example hall current sensor etc. because common hall current sensor has taken compensating element certainly, but the compensation effect can not reach best, can be not up to standard because the production condition influences, so adopt the compensating element of external formula can reduce the defect of preparation technology, produce the compensating coil base alone and also can play the effect.

Description

Zero-flux high-precision current transformer

Technical Field

The utility model relates to a filtering technology, current transformer technical field, concretely relates to zero magnetic flux high accuracy current transformer.

Background

The mutual inductor is also called instrument transformer, and is a general name of current mutual inductor and voltage mutual inductor. The high voltage can be changed into low voltage, and the large current can be changed into small current for measuring or protecting the system. Its function is mainly to convert high voltage or large current into standard low voltage (100V) or standard small current (5A or 1A, both referring to rated value) in proportion so as to realize standardization and miniaturization of measuring instrument, protection equipment and automatic control equipment. Meanwhile, the mutual inductor can be used for isolating a high-voltage system so as to ensure the safety of people and equipment.

Wherein the error of the current transformer is generated by an alternating excitation current providing a magnetic flux. If the magnetic flux is zero, the transformer can be said to have no error, and the accuracy can be greatly improved. This is a practical significance of zero flux current transformers. The transformer needs to have a current output. Even with an external short (0 load), there is a voltage drop due to the internal resistance of the coil. This voltage drop is provided by the electromotive force generated by the alternating magnetic flux. There are several ways to solve the current problem of zero flux. One approach is to use another auxiliary transformer superimposed on the main transformer to provide back emf to compensate for the voltage drop created by I x R. The magnetic flux of the main transformer is not required to provide an electromotive force for the purpose of zero magnetic flux. Another method is to use an external circuit to provide, but the external circuit that provides accurate in-phase electromotive force needs a little work. The former method is easier to implement and more accurate. Theoretically, the zero-flux current transformer has no error, but because zero flux cannot be achieved, leakage inductance of a distributed capacitor is added, and the like, the zero-flux current transformer has an error. But the accuracy of the average transformer is improved by at least one order of magnitude, and a power supply is not needed, so that the method has a wide prospect if the price is reduced.

SUMMERY OF THE UTILITY MODEL

To the defect among the prior art, the utility model provides a zero magnetic flow high accuracy current transformer reaches the magnetic potential through increasing external compensating coil balanced to filter capacitance reduction oscillation has still been increased in compensating coil's return circuit.

Zero magnetic flux high accuracy current transformer, including main body cover, compensating coil base, be provided with current transformer in the main body cover, the main body cover surface sets up load interface, this load interface with current transformer electric connection, set up compensating coil and be used for twining this compensating coil's iron core in the compensating coil base.

The utility model adopts the mode of increasing the compensation coil to ensure that the magnetic core in the current transformer reaches the magnetic potential balance, so that the magnetic core can be always kept in the state of approaching zero magnetic flux, and the used sensor can reach higher precision; the utility model discloses applicable occasion such as commercial power detection, household power consumption detect, adopt the design of punching the formula, current transformer can adopt prior art, for example hall current sensor etc. because common hall current sensor has taken compensating element certainly, but the compensation effect can not reach best, can be not up to standard because the production condition influences, so adopt the compensating element of external formula can reduce the defect of preparation technology, produce the compensating coil base alone and also can play the effect.

Further, the main body shell is a cylinder with a central shaft provided with a channel.

Furthermore, the current transformer comprises a magnetic core and a winding, wherein the magnetic core is annular, and the winding is wound on the magnetic core.

Further, the load interface is electrically connected with the winding.

Furthermore, in order to facilitate connection, the compensation coil base is detachably connected with the main body shell.

Further, the compensation coil base is connected with the main body shell through threads.

Furthermore, the compensation coil base is connected with the main body shell through a buckle.

Furthermore, in order to reduce current oscillation, one end of the compensation coil is connected in parallel with one end of a capacitor C1 and one end of a resistor R1, the other end of the capacitor C1 is grounded, the other end of the resistor R1 is connected with a load L1, and the compensation coil and the load L1 form a loop. The load L1 is prior art.

The beneficial effects of the utility model are embodied in:

the utility model adopts the mode of increasing the compensation coil to ensure that the magnetic core in the current transformer reaches the magnetic potential balance, so that the magnetic core can be always kept in the state of approaching zero magnetic flux, and the used sensor can reach higher precision; the utility model discloses can be applicable to occasions such as commercial power detection, household electricity consumption detection, adopt the design of punching the heart, current transformer can adopt prior art, for example hall current sensor etc. because common hall current sensor has compensation element by itself, but compensation effect can not reach the best, can be because production condition influences not up to standard, so adopt the compensation element of external connection formula can reduce the defect of manufacture craft, produce the compensation coil base alone and can also play a role; the magnetic potential balance is achieved by adding an external compensation coil, and a filter capacitor is added in a loop of the compensation coil to reduce oscillation; the cost is reduced and the productivity is improved.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below. Throughout the drawings, like elements or portions are generally identified by like reference numerals. In the drawings, elements or portions are not necessarily drawn to scale.

Fig. 1 is a schematic structural view of the present invention;

fig. 2 is a schematic diagram of the compensation coil base of the present invention.

In the figure, 1-main body shell, 2-compensation coil base, 21-iron core, 22-compensation coil, 3-channel and 4-load interface.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. The following examples are only for illustrating the technical solutions of the present invention more clearly, and therefore are only examples, and the protection scope of the present invention is not limited thereby.

It is to be noted that unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which the present invention belongs.

As shown in fig. 1 and 2, the zero-flux high-precision current transformer includes a main body case 1 and a compensation coil base 2, the current transformer is disposed in the main body case 1, a load interface 4 is disposed on a surface of the main body case 1, the load interface 4 is electrically connected to the current transformer, and a compensation coil 22 and an iron core 21 for winding the compensation coil 22 are disposed in the compensation coil base 2.

The utility model adopts the mode of increasing the compensation coil to ensure that the magnetic core in the current transformer reaches the magnetic potential balance, so that the magnetic core can be always kept in the state of approaching zero magnetic flux, and the used sensor can reach higher precision; the utility model discloses applicable occasion such as commercial power detection, household power consumption detect, adopt the design of punching the formula, current transformer can adopt prior art, for example hall current sensor etc. because common hall current sensor has taken compensating element certainly, but the compensation effect can not reach best, can be not up to standard because the production condition influences, so adopt the compensating element of external formula can reduce the defect of preparation technology, produce compensating coil base 2 alone and also can play the effect.

The main body shell 1 is a cylinder with a central shaft provided with a channel 3.

The current transformer comprises a magnetic core and a winding, wherein the magnetic core is annular, and the winding is wound on the magnetic core.

The load interface 4 is electrically connected with the winding.

For convenient connection, the compensation coil base 2 is detachably connected with the main body housing 1.

The compensation coil base 2 with the main body cover 1 passes through threaded connection, in this embodiment the compensation coil base 2 with be equipped with the screw thread that is used for connecting on the main body cover 1, and the screw thread phase-match can adopt prior art.

The compensation coil base 2 and the main body housing 1 are connected through a buckle, and the buckle connection is the prior art.

In order to reduce current oscillation, one end of the compensation coil 22 is connected in parallel with one end of a capacitor C1 and one end of a resistor R1, the other end of the capacitor C1 is grounded, the other end of the resistor R1 is connected with a load L1, and the compensation coil 22 and the load L1 form a loop. The load L1 is prior art.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the scope of the embodiments of the present invention, and are intended to be covered by the claims and the specification.

Claims

1. Zero magnetic flux high accuracy current transformer, its characterized in that: including main body cover (1), compensating coil base (2), be provided with current transformer in main body cover (1), main body cover (1) surface sets up load interface (4), this load interface (4) with current transformer electric connection, set up compensating coil (22) and be used for twining iron core (21) of this compensating coil (22) in compensating coil base (2).

2. The zero-flux high-precision current transformer of claim 1, wherein: the main body shell (1) is a cylinder with a central shaft provided with a channel (3).

3. The zero-flux high-precision current transformer of claim 1, wherein: the current transformer comprises a magnetic core and a winding, wherein the magnetic core is annular, and the winding is wound on the magnetic core.

4. The zero-flux high-precision current transformer of claim 3, wherein: the load interface (4) is electrically connected with the winding.

5. The zero-flux high-precision current transformer of claim 1, wherein: the compensation coil base (2) is detachably connected with the main body shell (1).

6. The zero-flux high-precision current transformer of claim 5, wherein: the compensation coil base (2) is connected with the main body shell (1) through threads.

7. The zero-flux high-precision current transformer of claim 5, wherein: the compensation coil base (2) is connected with the main body shell (1) through a buckle.

8. The zero-flux high-precision current transformer of claim 1, wherein: one end of the compensation coil (22) is connected in parallel with one end of a capacitor C1 and one end of a resistor R1, the other end of the capacitor C1 is grounded, the other end of the resistor R1 is connected with a load L1, and the compensation coil (22) and the load L1 form a loop.