Voltage measurement device and method for a three-phase common tank GIS device

Abstract

The application relates to a voltage measuring device and method of a three-phase common tank GIS device, which comprises a basin type insulator, an induction cylinder and a collection board card, the induction cylinder is composed of a metal inner wall and a metal outer wall fixed by a structure support, the induction cylinder is fixed in a hole of the basin type insulator, the collection board card is connected with the metal inner wall and the metal outer wall of the induction cylinder respectively, and the collection board card is used for reducing the voltage of the three-phase common tank GIS device. The technical scheme provided by the application omits the high-voltage capacitor, the medium-voltage capacitor and the intermediate transformer in the traditional capacitor voltage division mutual inductor, and has no ferromagnetic resonance problem; the influence of the coupling capacitor between the phase-to-phase conductive rods on the phase measurement is eliminated, independent measurement of three phases is realized; the influence of the induction capacitor formed by the metal inner wall and the metal outer wall and the induction capacitor formed by the metal outer wall and the ground on the circuit is eliminated, and the accuracy of the measuring device is ensured by adjusting the variable resistor on the collection board card.

Description

Technical Field

[0001] The present invention belongs to the field of intelligent measurement of power systems, and in particular relates to a voltage measurement device and method for three-phase common box GIS equipment. Background Art

[0002] Three-phase gas-insulated switchgear (GIS) devices have many advantages, such as energy saving, small footprint, low probability of gas leakage, and easy installation. They are widely used in power grids, so voltage measurements are often performed on three-phase GIS devices.

[0003] Voltage transformers are important signal acquisition devices in power grids. Currently, the voltage transformers used in power grids at home and abroad are mainly electromagnetic voltage transformers (PT) and capacitive voltage transformers (CVT). Capacitive voltage transformers are mainly used for voltage measurement in three-phase common box GIS equipment, such as Figure 1 As shown in the figure, the capacitor voltage transformer adopts a three-phase common box structure, with its three-phase arc extinguishing chambers installed in a single housing. The capacitor voltage transformer includes high-voltage capacitors, medium-voltage capacitors, an intermediate transformer, a damper, a compensating reactor, a zinc oxide lightning arrester, a drain coil, a protective gap, and an earthing switch. The capacitor voltage transformer uses the principle of capacitive voltage division, dividing the high voltage on the bus side through series capacitors. The 10-20kV voltage is extracted at the low-voltage end and then stepped down through an intermediate transformer to produce three sets of 57.7V phase voltages and one set of 100V open-delta voltages.

[0004] However, capacitive voltage transformers still suffer from the ferromagnetic resonance problem of electromagnetic transformers. Furthermore, capacitive voltage transformers are bulky and require high insulation requirements. They require separate compartments for installation in three-phase GIS equipment, resulting in a large footprint and high equipment and space costs. Therefore, it is necessary to provide a voltage measurement device and method for three-phase GIS equipment that can overcome these shortcomings. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the purpose of the present invention is to provide a voltage measuring device and method that can accurately measure the voltage of three-phase common-box GIS equipment. Through the voltage measuring device of three-phase common-box GIS equipment, the volume of the device can be reduced, independent measurement of the three phases can be achieved, and the problem of ferromagnetic resonance can be overcome.

[0006] The purpose of the present invention is achieved by adopting the following technical solutions:

[0007] A voltage measuring device for three-phase common-box GIS equipment, the improvement of which is that the device comprises: a pot-type insulator, an induction cylinder, and a collection board, wherein the induction cylinder is composed of a metal inner wall and a metal outer wall fixed by a structural support member;

[0008] The induction cylinder is fixed in the hole of the pot-type insulator;

[0009] The acquisition boards are respectively connected to the metal inner wall and the metal outer wall of the sensing cylinder;

[0010] The acquisition board is used to reduce the voltage of the three-phase common box GIS equipment.

[0011] Preferably, the height of the metal outer wall is greater than the height of the metal inner wall.

[0012] Preferably, the conductive rod in the three-phase common box GIS equipment is placed at the central axis of the induction cylinder.

[0013] Preferably, the acquisition board includes a first operational amplifier, a first regulating unit and a second regulating unit;

[0014] The inverting input terminal of the first operational amplifier is connected to the metal inner wall, the non-inverting input terminal of the first operational amplifier is connected to the metal outer wall, and the output terminal of the first operational amplifier is connected to the input terminal of the second adjustment unit;

[0015] The connection point between the inverting input terminal of the first operational amplifier and the metal inner wall is connected to the input terminal of the first adjustment unit, the connection point between the non-inverting input terminal of the first operational amplifier and the metal outer wall is grounded, and the connection point between the output terminal of the first operational amplifier and the input terminal of the second adjustment unit is connected to the output terminal of the first adjustment unit.

[0016] Furthermore, the first regulating unit includes: a first voltage-stabilizing diode, a second voltage-stabilizing diode, a first resistor, a first capacitor, a second resistor, and a control switch;

[0017] The input end of the first regulating unit is connected to the positive electrode of the first voltage regulator tube, the negative electrode of the first voltage regulator tube is connected to the negative electrode of the second voltage regulator tube, and the positive electrode of the second voltage regulator tube is connected to the output end of the first regulating unit;

[0018] The input end of the first regulating unit is connected to one end of the first resistor, and the other end of the first resistor is connected to the output end of the first regulating unit;

[0019] The input end of the first regulating unit is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected to the output end of the first regulating unit;

[0020] The second resistor is connected in parallel with the control switch;

[0021] The second regulating unit includes: a third resistor, a variable resistor and a second operational amplifier;

[0022] The input end of the second regulating unit is connected to one end of the third resistor, the other end of the third resistor is connected to the inverting input end of the second operational amplifier, and the non-inverting input end of the second operational amplifier is grounded;

[0023] A connection point between the other end of the third resistor and the inverting input terminal of the second operational amplifier is connected to one end of the variable resistor, and the other end of the variable resistor is connected to the output terminal of the second operational amplifier.

[0024] Specifically, the AC signal voltage at the output end of the first operational amplifier in the acquisition board is the voltage of the three-phase common box GIS device after reduction, wherein the reduction ratio is R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C e It is the capacitance of the coupling capacitor formed between the metal inner wall of the induction cylinder and the conductive rod.

[0025] Specifically, the resistance value of the variable resistor R 2ref The acquisition process includes:

[0026] Turn off the control switch and apply a corrective AC signal to one end of the conductive rod in the three-phase common box GIS equipment;

[0027] Adjust the resistance of the variable resistor to R 2ref :

[0028]

[0029] Where f is the frequency of the corrected AC signal, C e is the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, R cal is the resistance of the second resistor, R f is the resistance of the first resistor, and R1 is the resistance of the third resistor.

[0030] A voltage measurement method for a three-phase common box GIS device based on the voltage measurement device, wherein the improvement is that the method comprises:

[0031] Turn on the control switch in the acquisition board;

[0032] Determine the voltage V of the three-phase common box GIS equipment under test by the following formula sys :

[0033]

[0034] Where R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C eis the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, V 2out After the conductive rod is connected to the three-phase power grid, the AC signal voltage at the output end of the first operational amplifier in the board is collected.

[0035] Compared with the closest prior art, the present invention has the following beneficial effects:

[0036] The technical solution provided by the present invention is aimed at accurately measuring the voltage of three-phase common-box GIS equipment. The voltage measuring device for three-phase common-box GIS equipment provided has a compact structure and small size, eliminates the high-voltage capacitors, medium-voltage capacitors, intermediate transformers, etc. in traditional capacitor voltage divider transformers, and has no ferromagnetic resonance problem.

[0037] The inductive cylinder shielding structure in the voltage measuring device of the three-phase common box GIS equipment eliminates the influence of the coupling capacitance between the conductive rods between phases on the measurement of the phase, and realizes independent measurement of the three phases.

[0038] The acquisition board in the voltage measurement device of the three-phase common box GIS equipment uses the characteristic that the positive and negative terminals of the operational amplifier have basically the same potential to clamp the potential of the metal inner wall to the ground potential, eliminating the influence of the spatial induction capacitance formed by the metal inner wall and the metal outer wall and the capacitance formed by the metal outer wall and the ground on the circuit.

[0039] The control switch in the voltage measuring device of the three-phase common box GIS equipment realizes the separation of calibration and measurement. The measurement circuit can be calibrated using only a small signal. The measurement device is corrected by adjusting the variable resistor on the acquisition board, ensuring the accuracy of the measurement device.

[0040] The voltage method of three-phase common box GIS equipment based on the voltage measurement device of three-phase common box GIS equipment has a simple process and is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 It is a circuit diagram of a capacitive voltage transformer in the background technology of the present invention;

[0042] Figure 2 This is a schematic structural diagram of a voltage measuring device for a three-phase common box GIS device according to an embodiment of the present invention;

[0043] Figure 3 This is a schematic structural diagram of an induction cylinder in a voltage measurement device for a three-phase common-box GIS device according to an embodiment of the present invention;

[0044] Figure 4 This is a diagram showing the positional relationship between the conductive rod and the induction cylinder in a three-phase common box GIS device according to an embodiment of the present invention;

[0045] Figure 5This is a circuit diagram of a voltage measuring device for a three-phase common box GIS device according to an embodiment of the present invention;

[0046] Figure 6 This is a flow chart of a voltage measurement method for a three-phase common box GIS device according to an embodiment of the present invention;

[0047] Among them, C1 is a high-voltage capacitor, C2 is a medium-voltage capacitor, T is an intermediate transformer, ZD is a damper, L is a compensating reactor, BL is a damper, L1 is a drain coil, P is a protective gap, K is a grounding switch, Out is an output terminal, I is a pot-type insulator, II is an induction cylinder, III is an acquisition board, II_1 is a metal outer wall, II_2 is a structural support, and II_3 is a metal inner wall. DETAILED DESCRIPTION

[0048] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0050] This embodiment provides a voltage measurement device for a three-phase GIS device. Figure 2 As shown, the device includes: a basin insulator I, an induction cylinder II and a collection board III;

[0051] like Figure 3 As shown, the induction cylinder II is composed of a metal inner wall II_3 and a metal outer wall II_1 fixed by a structural support II_2;

[0052] The induction cylinder II is fixed in the hole of the pot-type insulator I;

[0053] The acquisition board III is connected to the metal inner wall II_3 and the metal outer wall II_1 of the sensing cylinder II respectively;

[0054] The acquisition board III is used to reduce the voltage of the three-phase common box GIS equipment.

[0055] Furthermore, the height of the metal outer wall II_1 is greater than the height of the metal inner wall II_3, so that the coupling capacitance Ci formed between the metal inner wall II_3 and the metal outer wall II_1 is much greater than the coupling capacitance C formed between the conductive rod and the metal inner wall II_3. e , thereby reducing the partial pressure on Ci;

[0056] in Where L0 is the height of the metal outer wall, L 01 is the radius of the metal outer wall, L 02 is the radius of the metal inner wall, and ε is the coupling parameter.

[0057] Further, such as Figure 4 As shown, the conductive rod in the three-phase common box GIS equipment is placed at the central axis of the induction cylinder II.

[0058] Furthermore, the circuit diagram of the voltage measuring device is as follows Figure 5 As shown, the acquisition board III includes a first operational amplifier, a first regulating unit and a second regulating unit;

[0059] The inverting input terminal of the first operational amplifier is connected to the metal inner wall, the non-inverting input terminal of the first operational amplifier is connected to the metal outer wall, and the output terminal of the first operational amplifier is connected to the input terminal of the second adjustment unit;

[0060] The connection point between the inverting input terminal of the first operational amplifier and the metal inner wall is connected to the input terminal of the first adjustment unit, the connection point between the non-inverting input terminal of the first operational amplifier and the metal outer wall is grounded, and the connection point between the output terminal of the first operational amplifier and the input terminal of the second adjustment unit is connected to the output terminal of the first adjustment unit.

[0061] Specifically, the first regulating unit includes: a first voltage regulator tube, a second voltage regulator tube, a first resistor, a first capacitor, a second resistor and a control switch;

[0062] The input end of the first regulating unit is connected to the positive electrode of the first voltage regulator tube, the negative electrode of the first voltage regulator tube is connected to the negative electrode of the second voltage regulator tube, and the positive electrode of the second voltage regulator tube is connected to the output end of the first regulating unit;

[0063] The input end of the first regulating unit is connected to one end of the first resistor, and the other end of the first resistor is connected to the output end of the first regulating unit;

[0064] The input end of the first regulating unit is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected to the output end of the first regulating unit;

[0065] The second resistor is connected in parallel with the control switch;

[0066] The second regulating unit includes: a third resistor, a variable resistor and a second operational amplifier;

[0067] The input end of the second regulating unit is connected to one end of the third resistor, the other end of the third resistor is connected to the inverting input end of the second operational amplifier, and the non-inverting input end of the second operational amplifier is grounded;

[0068] A connection point between the other end of the third resistor and the inverting input terminal of the second operational amplifier is connected to one end of the variable resistor, and the other end of the variable resistor is connected to the output terminal of the second operational amplifier.

[0069] Specifically, the AC signal voltage at the output end of the first operational amplifier in the acquisition board is the voltage of the three-phase common box GIS device after reduction, wherein the reduction ratio is R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C e is the capacitance of the coupling capacitor formed between the metal inner wall II_3 in the induction cylinder II and the conductive rod.

[0070] Specifically, the resistance value of the variable resistor R 2ref The acquisition process includes:

[0071] Turn off the control switch and apply a corrective AC signal to one end of the conductive rod in the three-phase common box GIS equipment;

[0072] Determine the AC signal voltage V at the output of the first operational amplifier in the acquisition board after the conductive rod is connected to the rectified AC signal. 1out :

[0073]

[0074] Where s = j2πf, is the Laplace operator, f is the frequency of the corrected AC signal, V sig To correct the voltage of the AC signal, C e C is the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, f is the capacitance of the first capacitor, R cal is the resistance of the second resistor, R2 is the resistance of the variable resistor before correction, R f is the resistance value of the first resistor, R1 is the resistance value of the third resistor;

[0075] Generally, f=50Hz can be taken;

[0076] In order to make the corrected V 1out =V sig , press the formula to adjust the resistance of the variable resistor to R 2ref :

[0077]

[0078] In this embodiment, R f =1GΩ, R cal =680MΩ, if C e=50pF, then R 2ref =R1; If environmental factors cause C e Not equal to 50pF, then

[0079] A voltage measurement method for a three-phase common box GIS device based on the voltage measurement device, such as Figure 6 As shown, the method includes:

[0080] S101. Turn on the control switch in acquisition board III;

[0081] S102. Determine the voltage V of the three-phase GIS device under test according to the following formula sys :

[0082]

[0083] Where R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C e is the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, V 2out After the conductive rod is connected to the three-phase power grid, the AC signal voltage at the output end of the first operational amplifier in the board is collected.

[0084] Those skilled in the art will appreciate that the embodiments of the present application can be provided as methods, systems, or computer program products. Therefore, the present application can adopt the form of a complete hardware embodiment, a complete software embodiment, or an embodiment in combination with software and hardware. Moreover, the present application can adopt the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) that contain computer-usable program code.

[0085] The present application is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to the embodiments of the present application. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of the processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device generate instructions for implementing the steps in the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A device that provides the functions specified in a block or multiple blocks.

[0086] These computer program instructions may also be stored in a computer readable memory that can direct a computer or other programmable data processing device to work in a specific manner, so that the instructions stored in the computer readable memory produce an article of manufacture comprising an instruction device, which implements the process Figure 1 a process or multiple processes and / or boxes Figure 1 The function specified in one or more boxes.

[0087] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operational steps are executed on the computer or other programmable device to produce a computer-implemented process, thereby providing the instructions executed on the computer or other programmable device for implementing the process. Figure 1 a process or multiple processes and / or boxes Figure 1 A step that specifies a function in one or more boxes.

[0088] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or replaced by equivalents. Any modification or equivalent replacement that does not depart from the spirit and scope of the present invention should be covered by the scope of protection of the claims of the present invention.

Claims

1. A voltage measuring device for three-phase GIS equipment, characterized in that: The device comprises: a pot-type insulator, an induction cylinder and a collection board, wherein the induction cylinder is composed of a metal inner wall and a metal outer wall fixed by a structural support member; The induction cylinder is fixed in the hole of the pot-type insulator; The acquisition boards are respectively connected to the metal inner wall and the metal outer wall of the sensing cylinder; The acquisition board is used to reduce the voltage of the three-phase common box GIS equipment; The acquisition board includes a first operational amplifier, a first adjustment unit and a second adjustment unit; The inverting input terminal of the first operational amplifier is connected to the metal inner wall, the non-inverting input terminal of the first operational amplifier is connected to the metal outer wall, and the output terminal of the first operational amplifier is connected to the input terminal of the second adjustment unit; The connection point between the inverting input terminal of the first operational amplifier and the metal inner wall is connected to the input terminal of the first adjustment unit, the connection point between the non-inverting input terminal of the first operational amplifier and the metal outer wall is grounded, and the connection point between the output terminal of the first operational amplifier and the input terminal of the second adjustment unit is connected to the output terminal of the first adjustment unit; The first regulating unit includes: a first voltage-stabilizing diode, a second voltage-stabilizing diode, a first resistor, a first capacitor, a second resistor, and a control switch; The input end of the first regulating unit is connected to the positive electrode of the first voltage regulator tube, the negative electrode of the first voltage regulator tube is connected to the negative electrode of the second voltage regulator tube, and the positive electrode of the second voltage regulator tube is connected to the output end of the first regulating unit; The input end of the first regulating unit is connected to one end of the first resistor, and the other end of the first resistor is connected to the output end of the first regulating unit; The input end of the first regulating unit is connected to one end of the first capacitor, the other end of the first capacitor is connected to one end of the second resistor, and the other end of the second resistor is connected to the output end of the first regulating unit; The second resistor is connected in parallel with the control switch; The second regulating unit includes: a third resistor, a variable resistor and a second operational amplifier; The input end of the second regulating unit is connected to one end of the third resistor, the other end of the third resistor is connected to the inverting input end of the second operational amplifier, and the non-inverting input end of the second operational amplifier is grounded; A connection point between the other end of the third resistor and the inverting input terminal of the second operational amplifier is connected to one end of the variable resistor, and the other end of the variable resistor is connected to the output terminal of the second operational amplifier.

2. The voltage measuring device according to claim 1, wherein The height of the metal outer wall is greater than the height of the metal inner wall.

3. The voltage measuring device according to claim 1, wherein: The conductive rod in the three-phase common box GIS equipment is placed at the central axis of the induction cylinder.

4. The voltage measuring device according to claim 1, wherein: The AC signal voltage at the output end of the first operational amplifier in the acquisition board is the voltage of the three-phase common box GIS device after reduction, wherein the reduction ratio is R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C e It is the capacitance of the coupling capacitor formed between the metal inner wall of the induction cylinder and the conductive rod.

5. The voltage measuring device according to claim 4, wherein: The resistance value of the variable resistor R 2ref The acquisition process includes: Turn off the control switch and apply a corrective AC signal to one end of the conductive rod in the three-phase common box GIS equipment; Adjust the resistance of the variable resistor to R 2ref : Where f is the frequency of the corrected AC signal, C e is the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, R cal is the resistance of the second resistor, R f is the resistance of the first resistor, and R1 is the resistance of the third resistor.

6. A voltage measurement method for a three-phase common box GIS device based on the voltage measurement device according to any one of claims 1 to 5, characterized in that: The method comprises: Turn on the control switch in the acquisition board; Determine the voltage V of the three-phase common box GIS equipment under test by the following formula sys : Where R 2ref is the resistance of the variable resistor, R1 is the resistance of the third resistor, C f is the capacitance of the first capacitor, C e is the capacitance of the coupling capacitor formed between the metal inner wall of the inductive cylinder and the conductive rod, V 2out After the conductive rod is connected to the three-phase power grid, the AC signal voltage at the output end of the first operational amplifier in the board is collected.

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