Three-phase composite capacitance voltage division type voltage sensor for primary and secondary fusion of power distribution

Abstract

The utility model discloses a three-phase composite capacitance voltage-dividing type voltage sensor for primary and secondary fusion of power distribution. The three-phase composite capacitance voltage-dividing type voltage sensor comprises an insulating shell, a capacitance voltage-dividing type voltage module and a secondary adjusting unit, the capacitive voltage division type voltage module is accommodated in the cavity of the insulating shell; each phase of the capacitive voltage division type voltage module comprises a phase sequence high-voltage arm composite capacitor, a phase sequence low-voltage arm composite capacitor, a zero-sequence high-voltage arm composite capacitor and a zero-sequence low-voltage arm composite capacitor, and each composite capacitor is a ceramic film composite capacitor; a high-voltage terminal is arranged at the upper end of the insulating shell, a five-core double-shielded wire is arranged at the lower end of the insulating shell, one end of the five-core double-shielded wire is electrically connected with the capacitive voltage division type voltage module, and the other end of the five-core double-shielded wire is connected with the secondary adjusting unit through an aviation plug; and a compensation capacitor and a compensation resistor are arranged in the secondary adjustment unit. The voltage sensor provided by the utility model is compact in structure, small in size, light in weight, simple in wiring and excellent in performance, and adopts aviation plug butt joint.

Description

Technical Field

[0001] The utility model relates to the technical field of automatic sampling control of power distribution networks, in particular to a three-phase composite capacitor voltage divider type voltage sensor for primary and secondary integration of power distribution. Background Art

[0002] As the State Grid has made clear requirements for refined line loss management and primary and secondary integration technology of distribution networks, new technical and testing requirements are proposed for current and voltage sensors of distribution network equipment. With the rapid development of electronic technology, the information and energy supply of the control part in protection and measurement are separated, and sensors with low power output meet the sampling requirements. In addition, the China Electrotechnical Society has proposed the group standard "Technical Conditions for 10kV and 20kV AC Sensors in Distribution Networks", which regulates the design, manufacture and testing of voltage sensors based on the impedance voltage division principle. The existing voltage sensors for primary and secondary integration of ZW32 type pole-mounted circuit breakers are large in size, weak in load capacity, and unstable in performance. Therefore, it is urgent to develop a voltage sensor that can be sealed or installed in the ZW32 pole with a compact structure, small size, light weight, and stable performance. Utility Model Content

[0003] In order to solve the problems of large size, weak load capacity and unstable performance of the existing voltage sensor for primary and secondary fusion of ZW32 type pole-mounted circuit breaker switch, the utility model proposes a three-phase composite capacitor voltage divider voltage sensor device for primary and secondary fusion of power distribution with compact structure, small size, light weight and stable performance.

[0004] A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution, comprising an insulating shell, a capacitor voltage divider voltage module and a secondary adjustment unit; the capacitor voltage divider voltage module is accommodated in the cavity of the insulating shell, and the cavity of the insulating shell is filled with epoxy resin; each phase of the capacitor voltage divider voltage module includes a phase sequence high-voltage arm composite capacitor, a phase sequence low-voltage arm composite capacitor, a zero-sequence high-voltage arm composite capacitor and a zero-sequence low-voltage arm composite capacitor, and the phase sequence high-voltage arm composite capacitor, the phase sequence low-voltage arm composite capacitor, the zero-sequence high-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor are all ceramic film composite capacitors; a high-voltage terminal is provided at the upper end of the insulating shell, a five-core double-shielded wire is provided at the lower end of the insulating shell, the output end of the capacitor voltage divider voltage module is electrically connected to one end of the five-core double-shielded wire, and the other end of the five-core double-shielded wire is electrically connected to the secondary adjustment unit through an aviation plug, and the output end of the secondary adjustment unit is provided with an aviation plug; a compensation capacitor and a compensation resistor are provided in the secondary adjustment unit.

[0005] Furthermore, the insulating shell is cylindrical.

[0006] Furthermore, the compensation resistor is a low-temperature drift non-inductive metal film resistor.

[0007] Furthermore, the high-voltage terminal is a copper insert, and the copper insert is embedded in the top of the insulating shell.

[0008] Furthermore, a plastic cover is provided at the bottom of the insulating shell, and a lead-out hole for the five-core double-shielded wire to pass through is provided on the plastic cover.

[0009] Furthermore, a hexagonal fastening hole is provided at the center of the plastic cover.

[0010] Furthermore, the capacitance of the phase-sequence high-voltage arm composite capacitor and the zero-sequence high-voltage arm composite capacitor are both 600pF.

[0011] Furthermore, the phase sequence low voltage arm composite capacitor has a capacitance of 1.6 μF, and the zero sequence low voltage arm composite capacitor has a capacitance of 1.83 μF.

[0012] Furthermore, the error between the capacitance values ​​of the zero-sequence high-voltage arm composite capacitors of each phase is within 2 pF.

[0013] Furthermore, the capacitance of the compensation capacitor is 0.047 μF to 0.1 μF.

[0014] Beneficial effects of the utility model:

[0015] The utility model provides a three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution, which is a low-voltage, new type of measurement and protection voltage sensor with compact structure, small size and light weight. It is installed inside the pole of ZW32 type column-mounted circuit breaker. The low-voltage signal line is connected with an aviation plug, with simple wiring and excellent performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solution of the present invention, a brief introduction will be given to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only one embodiment of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0017] Figure 1 This is a schematic diagram of the structure of the composite capacitive voltage divider voltage sensor provided by the utility model;

[0018] Figure 2 This is a schematic diagram of the circuit structure of the capacitive voltage divider voltage module provided by the utility model.

[0019] Explanation of the reference numerals: 1. Insulating shell; 2. Capacitor voltage divider voltage module; 3. Five-core double-shielded wire; 4. Aviation plug. DETAILED DESCRIPTION

[0020] The following is a clear and complete description of the technical solution in the utility model in conjunction with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] like Figure 1 As shown, the present embodiment provides a three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution, including a cylindrical insulating shell 1, a capacitor voltage divider voltage module 2 and a secondary adjustment unit, wherein the capacitor voltage divider voltage module 2 is accommodated in the cavity of the insulating shell 1, and the cavity of the insulating shell 1 is filled with epoxy resin; each phase of the capacitor voltage divider voltage module 2 includes a phase sequence high-voltage arm composite capacitor C1, a phase sequence low-voltage arm composite capacitor C2, a zero-sequence high-voltage arm composite capacitor C3 and a zero-sequence low-voltage arm composite capacitor C4, and the phase sequence high-voltage arm composite capacitor, the phase sequence low-voltage arm composite capacitor, the zero-sequence high-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor are all ceramic film composite capacitors; a high-voltage terminal is provided at the upper end of the insulating shell 1, and a five-core double-shielded wire 3 is electrically connected to the lower end of the insulating shell 1, and the signal of the capacitor voltage divider voltage module 2 is led out through the five-core double-shielded wire, and the other end of the five-core double-shielded wire is electrically connected to the secondary adjustment unit through an aviation plug 4, and the output end of the secondary adjustment unit is connected to the terminal through an aviation plug; a compensation capacitor and a compensation resistor are provided in the secondary adjustment unit. The compensation resistor adopts a low temperature drift non-inductive metal film resistor. A copper insert is embedded in the top of the insulating housing 1, and the upper end of the copper insert is used as a threaded rod for high-voltage lead wiring. A plastic cover is installed at the bottom of the insulating housing 1. The plastic cover is provided with a lead-out hole for a five-core double shielded wire to pass through. A hexagonal fastening hole is embedded in the center of the plastic cover to realize the fastening connection of the voltage sensor device installed in the sealed pole, and the diameter of the fastening hole is less than 10mm.

[0022] Specifically, Figure 2 As shown, the three-phase circuit shares a zero-sequence low-voltage arm composite capacitor. In each phase circuit, the phase-sequence high-voltage arm composite capacitor and the phase-sequence low-voltage arm composite capacitor are connected in series, the zero-sequence high-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor are connected in series, and the phase-sequence high-voltage arm composite capacitor and the phase-sequence low-voltage arm composite capacitor are connected in parallel with the zero-sequence high-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor; an introduction line is provided on the high-voltage end of the phase-sequence high-voltage arm composite capacitor and the zero-sequence high-voltage arm composite capacitor in parallel, and the introduction line is connected to the high-voltage power supply U A , U B , U CThe low-voltage ends of the phase-sequence low-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor are grounded, and the voltages across the phase-sequence low-voltage arm composite capacitor in each phase circuit are taken as the phase-sequence secondary output voltages Ua, Ub, and Uc, and the voltages across the zero-sequence low-voltage arm composite capacitor are taken as the zero-sequence secondary output voltage Uo.

[0023] The three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution provided in this embodiment has a phase sequence high voltage arm composite capacitor and a zero sequence high voltage arm composite capacitor with a capacitance of 600pF, a phase sequence low voltage arm composite capacitor with a capacitance of 1.6μF, and a zero sequence low voltage arm composite capacitor with a capacitance of 1.83μF. The error between the zero sequence high voltage arm composite capacitor capacitances of each phase is within 2pF. A , U B , U C The phase sequence secondary output voltages Ua, Ub, Uc and zero sequence secondary output voltage Uo are obtained under the action of The voltage divider ratio obtained under Zero sequence low voltage arm composite capacitor at rated operating voltage The voltage divider ratio obtained under The compensation capacitor has a capacitance of 0.047μF to 0.1μF. The measured phase sequence secondary output voltage is The zero-sequence secondary output voltage is The above-mentioned voltage sensor is used in the ZW32 pole-mounted circuit breaker with deep integration of primary and secondary systems in power distribution equipment. It has the functions of three-phase voltage measurement and zero-sequence signal output, adopts capacitor voltage division, and the secondary output impedance is 2kΩ, which makes the voltage sensor have strong load capacity. The influence of the length of the five-core double-shielded cable on the accuracy is within the controllable error range.

[0024] The above is only a specific implementation of the utility model, but the protection scope of the utility model is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the utility model, which should be included in the protection scope of the utility model. Therefore, the protection scope of the utility model should be based on the protection scope of the claims.

Claims

1. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary power distribution, characterized in that: The invention comprises an insulating shell (1), a capacitor voltage-dividing voltage module (2) and a secondary adjustment unit; the capacitor voltage-dividing voltage module (2) is accommodated in a cavity of the insulating shell (1), and the cavity of the insulating shell (1) is filled with epoxy resin; each phase of the capacitor voltage-dividing voltage module (2) comprises a phase-sequence high-voltage arm composite capacitor, a phase-sequence low-voltage arm composite capacitor, a zero-sequence high-voltage arm composite capacitor and a zero-sequence low-voltage arm composite capacitor, and the phase-sequence high-voltage arm composite capacitor, the phase-sequence low-voltage arm composite capacitor, the zero-sequence high-voltage arm composite capacitor and the zero-sequence low-voltage arm composite capacitor are all ceramic film composite capacitors; a high-voltage terminal is arranged at the upper end of the insulating shell (1), a five-core double-shielded wire (3) is arranged at the lower end of the insulating shell (1), the output end of the capacitor voltage-dividing voltage module (2) is electrically connected to one end of the five-core double-shielded wire (3), and the other end of the five-core double-shielded wire is electrically connected to the secondary adjustment unit through an aviation plug (4), and the output end of the secondary adjustment unit is provided with an aviation plug; a compensation capacitor and a compensation resistor are arranged in the secondary adjustment unit.

2. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 1, characterized in that: The insulating shell (1) is cylindrical.

3. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 2, characterized in that: The compensation resistor is a low temperature drift non-inductive metal film resistor.

4. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 3, characterized in that: The high-voltage terminal is a copper insert, which is embedded in the top of the insulating shell (1).

5. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 4, characterized in that: The bottom of the insulating shell (1) is provided with a plastic cover, and the plastic cover is provided with a lead-out hole for the five-core double-shielded wire to pass through.

6. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 5, characterized in that: A hexagonal fastening hole is arranged at the center of the plastic cover.

7. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 6, characterized in that: The capacitance of the phase sequence high voltage arm composite capacitor and the zero sequence high voltage arm composite capacitor are both 600pF.

8. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 7, characterized in that: The composite capacitance of the phase sequence low voltage arm is 1.6μF, and the composite capacitance of the zero sequence low voltage arm is 1.83μF.

9. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 8, characterized in that: The error between the capacitance values ​​of the zero-sequence high-voltage arm composite capacitors of each phase is within 2pF.

10. A three-phase composite capacitor voltage divider voltage sensor for primary and secondary integration of power distribution as claimed in claim 9, characterized in that: The capacitance of the compensation capacitor is 0.047μF~0.1μF.

Images