CN217156622U - Magnetic balance alternating current sensor - Google Patents
Magnetic balance alternating current sensor Download PDFInfo
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- CN217156622U CN217156622U CN202123411844.XU CN202123411844U CN217156622U CN 217156622 U CN217156622 U CN 217156622U CN 202123411844 U CN202123411844 U CN 202123411844U CN 217156622 U CN217156622 U CN 217156622U
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
- Y02E40/00—Technologies for an efficient electrical power generation, transmission or distribution
- Y02E40/50—Arrangements for eliminating or reducing asymmetry in polyphase networks
Abstract
A magnetic balance alternating current sensor is applied to measurement and protection of a power distribution network of a three-phase circuit and comprises a flame-retardant shell, a magnetic balance sensor and a magnetic balance control circuit, wherein the flame-retardant shell is used for protecting the internal structure of the sensor; three circular preformed holes are alternately arranged in the flame-retardant shell and used for placing a three-phase circuit; the three phase sequence current coils are attached to the edges of the circular preformed hole and used for measuring the phase sequence current of the three-phase circuit; the three zero-sequence current coils are attached to the edges of the circular reserved holes, and each zero-sequence current coil is adjacent to each phase-sequence current coil and used for measuring the zero-sequence current of the three-phase circuit; and the non-inductive resistors are arranged in the flame-retardant shell, and the phase-sequence current coil and the zero-sequence current coil are arranged outside. Has the advantages that: the functions are various, the installation and the use are simple and convenient, the energy consumption is reduced in the operation, and the equipment maintenance is not needed; the sampling device has the advantages of light weight, small volume and wide measurement range, and overcomes the defects of narrow frequency band, slow response and the like of the traditional sampling device.
Description
Technical Field
The utility model relates to a magnetic balance alternating current sensor especially relates to a distribution network is with measuring magnetic balance alternating current sensor of protect function sharing.
Background
In order to meet the requirement of fine management of the line loss of the national power grid and realize the measurement of the line loss of the branch line of the power distribution network, a new requirement needs to be provided for a primary equipment current transformer so as to meet the requirement of measurement precision. With the rapid development of electronic technology, a microcomputer type relay protection device gradually takes a leading position, and in relay protection and measurement, energy flow and information flow of a control part are separated, so that a monitoring device does not need a transformer with high power output for sampling.
When the current sensor works at the temperature of between 40 ℃ below zero and 70 ℃ outdoors, the current sensor has a large error range, weak anti-interference capability, poor product ratio and phase difference which are easily interfered by external electromagnetic fields.
SUMMERY OF THE UTILITY MODEL
Due to the rapid development of the power industry and the more complex power grid conditions, the intelligent current sensor for improving the power factor and the quality of the power grid is widely applied. Because of the particularity of the pole switch and the ring main unit for the power distribution network, the utility model provides a magnetic balance AC current sensor shared by the measurement and protection functions for the power distribution network, which is used for providing current acquisition signals for a power distribution terminal FTU/DTU, and a magnetic balance phase zero sequence integrated bus current sensor shared by the measurement and protection functions with current sampling, measurement, zero sequence and protection functions, which is specially designed for the utility model, the utility model provides a magnetic balance AC current sensor applied to the measurement and protection of the power distribution network of a three-phase circuit, which is characterized by comprising,
a flame retardant housing for protecting the sensor internal structure;
three circular preformed holes are arranged in the flame-retardant shell in an inserting mode and used for placing a three-phase circuit;
the three phase sequence current coils are attached to the edge of the circular preformed hole, each phase sequence current coil comprises a first iron core and corresponds to one phase of the three-phase circuit, and the phase sequence current coils are used for measuring the phase sequence current of the three-phase circuit;
the three zero-sequence current coils are attached to the edge of the circular preformed hole, each zero-sequence current coil is adjacent to each phase-sequence current coil, each zero-sequence current coil comprises a second iron core and corresponds to one phase of the three-phase circuit, and the zero-sequence current coils are used for measuring the zero-sequence current of the three-phase circuit;
and the non-inductive resistors are arranged in the flame-retardant shell, and the phase-sequence current coil and the zero-sequence current coil are arranged outside.
Preferably, epoxy resin is filled between the flame-retardant shell and the circular reserved hole.
Preferably, the first iron core is formed by arranging a silicon steel sheet iron core and an amorphous iron core in a mixed manner.
Preferably, the second iron core is an amorphous iron core and is formed by a coil with high ampere turns.
Preferably, the three-phase circuit is coupled to each of the phase-sequence current coils, each of the phase-sequence current coils is connected in parallel to the non-inductive resistor, and outputs a first voltage signal through the non-inductive resistor, where the first voltage signal is a phase-sequence voltage and is generated when the phase sequence in the circuit is asymmetric.
Preferably, the three-phase circuit is coupled with the zero-sequence current coil, three phase-sequence current coils are connected in parallel and are connected in parallel with the non-inductive resistor, a second voltage signal is output through the non-inductive resistor, and the second voltage signal is zero-sequence voltage and is generated when the circuit is grounded and short-circuited.
Preferably, the phase-sequence current coil and the zero-sequence current coil are connected to the non-inductive resistor through a five-core shielding twisted pair.
Preferably, the zero sequence signal output generated by the zero sequence current coil is synthesized according to the zero sequence currents of three phases in the three-phase circuit.
Preferably, the first iron core and the second iron core are low-energy-consumption small iron cores, a primary winding is arranged outside the first iron core and the second iron core, a secondary winding is further arranged outside the first iron core and the second iron core, the non-inductive resistor is arranged on the secondary winding, a voltage drop is generated on the non-inductive resistor by a secondary current generated by the secondary winding, and the amplitude of the voltage drop is in direct proportion to a primary current of the primary winding and has the same phase.
Has the advantages that: the functions are various, the installation and the use are simple and convenient, the energy consumption is reduced in the operation, and the equipment maintenance is not needed; the weight is light, the volume is small, the installation space is saved, the field wiring is reduced, the structure is simple, and the performance is excellent; the measuring range is wide, and the defects of narrow frequency band, slow response and the like of the traditional electromagnetic sampling device are overcome; the small voltage signal sampling fundamentally eliminates major fault hidden dangers in the operation of the power system, and ensures the safety of personnel and equipment to the greatest extent.
Drawings
FIG. 1a is a front view of a current sensor according to a preferred embodiment of the present invention;
FIG. 1b is a side view of the current sensor according to the preferred embodiment of the present invention;
FIG. 2 is a schematic circuit diagram of a current sensor according to a preferred embodiment of the present invention;
fig. 3 is a schematic diagram of a small iron core coil of the current sensor according to the preferred embodiment of the present invention.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the accompanying drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by a person of ordinary skill in the art without creative efforts belong to the protection scope of the present invention.
It should be noted that, in the present invention, the embodiments and features of the embodiments may be combined with each other without conflict.
The present invention will be further described with reference to the accompanying drawings and specific embodiments, but the present invention is not limited thereto.
The utility model provides a magnetic balance alternating current sensor which is applied to the measurement and protection of a three-phase circuit distribution network and is characterized in that as shown in figure 1a, the magnetic balance alternating current sensor comprises,
a flame-retardant housing 1 for protecting the internal structure of the sensor;
three circular preformed holes 2 are arranged in the flame-retardant shell 1 in an inserting way;
the three phase sequence current coils 3 are attached to the edge of the circular preformed hole 2, each phase sequence current coil 3 comprises a first iron core and corresponds to one phase of the three-phase circuit;
the three zero-sequence current coils 4 are attached to the edge of the circular preformed hole 2, each zero-sequence current coil 4 is adjacent to each phase-sequence current coil 3, and each zero-sequence current coil 4 comprises a second iron core and corresponds to one phase of the three-phase circuit;
and the non-inductive resistors 5 are arranged in the flame-retardant shell 1 and outside the phase-sequence current coil 3 and the zero-sequence current coil 4.
Specifically, in the embodiment, the flame-retardant shell 1 is made of a flame-retardant material, so that the situation that a high temperature harms the sensor when a circuit fails is avoided, the circular preformed hole 2 is used for the three-phase circuit to pass through, and the sensor is placed on the inner side of the edge of the preformed hole, so that the real-time state of the three-phase circuit can be monitored;
the precision of the non-inductive resistor 5 is five parts per million, the temperature drift coefficient is small, the error range of the product is unchanged when the non-inductive resistor works at the temperature of between 40 ℃ below zero and 70 ℃ below zero, and the anti-jamming capability is strong.
In the preferred embodiment of the present invention, as shown in fig. 1b, epoxy resin 9 is filled between the flame-retardant casing 1 and the circular preformed hole 2.
Specifically, in the present embodiment, the epoxy resin 9 has excellent physical mechanical and electrical insulating properties, and is suitable for filling between the flame-retardant housing 1 and the circular prepared hole 2 as an easy injection molding material.
In the preferred embodiment of the present invention, the first iron core is formed by arranging the silicon steel sheet iron core 7 and the amorphous iron core 6 in a mixed manner.
Specifically, in this embodiment, the phase-sequence current coil 3 is internally combined with the phase-sequence silicon-steel sheet iron core 7 and the phase-sequence amorphous iron core 6, so that the sharing of the measurement protection function is ensured, and meanwhile, the magnetic balance of the phase-sequence circuit is ensured due to the consistency of the phase-sequence silicon-steel sheet iron core 7 and the phase-sequence amorphous iron core 6.
In the preferred embodiment of the present invention, the second iron core is an amorphous iron core 6 and is formed by a coil with high ampere turns.
Specifically, in this embodiment, the zero-sequence current coil 4 employs the amorphous iron core 6 for zero sequence and the scheme of high ampere-turns to ensure the common use of the measurement protection function, and meanwhile, the consistency of the amorphous iron core 6 for zero sequence and the metal film non-inductive resistor 5 with five ten-thousandth precision ensure the magnetic balance of the zero-sequence circuit by using the current synthesis principle.
In the preferred embodiment of the present invention, as shown in fig. 2, the three-phase circuit is coupled to each phase sequence current coil 3, and each phase sequence current coil 3 is connected in parallel to the non-inductive resistor 5.
Specifically, in this embodiment, when the phase sequence in the circuit is asymmetric, a phase sequence voltage is generated in a different phase, the automatic protection of the circuit can be realized by using the phase sequence voltage as a control variable, and when the phase sequence voltage occurs, a response is made in time.
The utility model discloses in the preferred embodiment, three zero sequence current coil 4 of three-phase circuit coupling, three zero sequence current coil 4 connect in parallel each other to connect in parallel a noninductive resistance 5 jointly.
Specifically, in this embodiment, when a ground short circuit occurs, a large zero-sequence voltage occurs, and the zero-sequence voltage is used as a control variable to protect the circuit from the ground short circuit, and the occurrence of the zero-sequence voltage proves that a ground end circuit occurs, so that a worker can timely handle the ground end circuit. Meanwhile, the output signal is more stable and reliable, and the anti-interference capability is stronger.
In the preferred embodiment of the present invention, the phase-sequence current coil 3 and the zero-sequence current coil 4 are connected to the non-inductive resistor 5 through the five-core shielded twisted pair 8.
Specifically, in this embodiment, the five-core shielded twisted pair 8 can prevent the product ratio difference and the phase difference from being interfered by an external electromagnetic field.
In the preferred embodiment of the present invention, as shown in fig. 3, the first iron core and the second iron core are small iron cores with low energy consumption, a primary winding is disposed outside the first iron core and the second iron core, a secondary winding a is further disposed outside the first iron core and the second iron core, and the secondary winding a is provided with an noninductive resistor 5.
Specifically, in the present embodiment, the small core coil type low power current sensor includes a primary winding small core and a secondary winding a with extremely small loss. The secondary winding a is connected with an integrated element, so that the secondary output of the integrated element is a voltage signal. The secondary current generates a voltage drop Us on the integrated component whose magnitude is proportional to the primary current and is in phase, and the smaller the secondary power required by the internal losses and load of the sensor, the wider the measurement range and the higher the accuracy.
The above description is only an example of the preferred embodiment of the present invention, and not intended to limit the scope of the present invention, and those skilled in the art should be able to realize the equivalent alternatives and obvious variations of the present invention.
Claims (8)
1. A magnetic balance alternating current sensor is applied to the measurement and protection of a power distribution network of a three-phase circuit and is characterized by comprising,
a flame retardant housing for protecting the sensor internal structure;
three circular preformed holes are arranged in the flame-retardant shell in an inserting mode;
the three phase sequence current coils are attached to the edge of the circular reserved hole, each phase sequence current coil comprises a first iron core and corresponds to one phase of the three-phase circuit;
the three zero-sequence current coils are attached to the edge of the circular preformed hole, each zero-sequence current coil is adjacent to each phase-sequence current coil, each zero-sequence current coil comprises a second iron core and corresponds to one phase of the three-phase circuit;
and the non-inductive resistors are arranged in the flame-retardant shell, and the phase-sequence current coil and the zero-sequence current coil are arranged outside.
2. A magnetically balanced alternating current sensor according to claim 1 wherein epoxy is filled between the flame retardant casing and the circular preformed hole.
3. The magnetically-balanced ac current sensor according to claim 1, wherein the first core is formed by a silicon steel sheet core and an amorphous core in a mixed arrangement.
4. A magnetically balanced alternating current sensor according to claim 1 wherein the second core is amorphous and is formed using a high ampere-turn coil.
5. A magnetically balanced alternating current sensor according to claim 1 wherein said three phase circuit is coupled to each of said phase sequence current coils, respectively, and each of said phase sequence current coils is connected in parallel with said non-inductive resistance, respectively.
6. A magnetically balanced alternating current sensor according to claim 5 wherein said three phase circuit couples said zero sequence current coils, three of said zero sequence current coils being connected in parallel with each other and in common with one of said non-inductive resistors.
7. A magnetically balanced alternating current sensor according to claim 6 wherein the phase-sequence current coil and the zero-sequence current coil are connected to the non-inductive resistance by a five-core shielded twisted pair.
8. The magnetically balanced ac current sensor according to claim 7, wherein the first core and the second core are low energy consuming small cores, a primary winding is disposed outside the first core and the second core, a secondary winding is disposed outside the first core and the second core, and the non-inductive resistor is disposed on the secondary winding.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123411844.XU CN217156622U (en) | 2021-12-30 | 2021-12-30 | Magnetic balance alternating current sensor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202123411844.XU CN217156622U (en) | 2021-12-30 | 2021-12-30 | Magnetic balance alternating current sensor |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN217156622U true CN217156622U (en) | 2022-08-09 |
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202123411844.XU Active CN217156622U (en) | 2021-12-30 | 2021-12-30 | Magnetic balance alternating current sensor |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN217156622U (en) |
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2021
- 2021-12-30 CN CN202123411844.XU patent/CN217156622U/en active Active
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