Auxiliary device for measuring characteristics of GIS (Gas Insulated Switchgear) switch

Abstract

The invention relates to the technical field of GIS (Gas Insulated Switchgear) equipment detection, and discloses a GIS switch characteristic measurement auxiliary device, which comprises a fracture time measurement loop connected with an oscilloscope, an opening and closing coil current measurement loop, an auxiliary switch measurement loop and a fracture time measurement loop, two ends of the capacitor are connected in parallel with two sides of the GCB fracture, and the first resistor is connected in parallel with an adjustable resistor. The adjustable resistor is added on the basis of an existing fracture time measurement loop, the size of the adjustable resistor can be adjusted according to the actual situation, the influence of the RC time constant of the fracture time measurement loop can be remarkably reduced or eliminated, the transition phenomenon of the waveform of a switch fracture is improved, the opening and closing time is accurately measured, and the measurement accuracy is improved. The product detection quality is improved, and the customer satisfaction is improved.

Description

Technical Field

[0001] The invention belongs to the technical field of GIS equipment detection, and in particular relates to a GIS switch characteristic measurement auxiliary device. Background Art

[0002] Circuit breakers, disconnectors, and earthing switches are important high-voltage electrical appliances in power systems. The opening and closing time and its synchronization, opening and closing speed and its overtravel, opening and closing coil current and its waveform are important parameters. Taking the circuit breaker as an example, the operating mechanism occupies an important position in the high-voltage circuit breaker. It not only has to ensure the long-term operation reliability of the circuit breaker, but also has to meet the requirements of the arc extinguishing characteristics for the operating mechanism. The opening and closing time or speed of the circuit breaker must meet its opening and closing requirements, so as to quickly cut off the fault without expanding the fault, so as to maintain the stability of the power system and reduce the damage to the equipment and line insulation at the fault point. For this reason, the circuit breaker is required to have good operating performance to meet the above requirements.

[0003] At present, the DL750 oscilloscope is generally used in conjunction with a large-scale operating test bench to complete the opening and closing characteristic test of circuit breakers, disconnectors, and earthing switches. However, the large-scale operating test bench is fixed in position and is large, heavy, and difficult to move, which increases the difficulty of mobile test operations.

[0004] In addition, the currently used large-scale operation test bench is difficult to use on-site in the substation. When the DL750 oscilloscope is used in conjunction with the control cabinet to conduct the switch opening and closing characteristic test on-site in the substation, there is no dedicated measurement auxiliary device between the DL750 oscilloscope and the break signal line, speed measurement signal line, and auxiliary switch signal line, and the oscilloscope channel input signal power supply (DC5V-24V) is not easy to obtain; in addition, the current signal of the opening and closing coil loop also needs to be taken by a clamp ammeter and input to the oscilloscope. Due to the limitations of the clamp ammeter gear setting, on-site environmental conditions, etc., the current waveform of the opening and closing coil loop is easily interfered by external factors, and the measured value has a certain error.

[0005] like Figure 1 As shown in the figure, taking this primary main wiring mode as an example, when the substation detects the circuit breaker opening and closing characteristics on site, the ES11 grounding bar cannot be removed due to the influence of the induced voltage on one side, and due to the influence of the ground capacitance of the cable CHd12 on the other side, the switch opening and closing characteristics test is equivalent to connecting a capacitor in parallel on both sides of the GCB (Gas Circuit Breaker, abbreviated as GCB, gas circuit breaker) break, especially when the cable line is long and the cable-to-ground capacitance is large. Figure 3 As shown in the figure, due to the large RC time constant in the measurement circuit, it is easy to cause the opening characteristic oscilloscope diagram measured by the oscilloscope to have a serious transition phenomenon. The opening characteristic waveform diagram is as follows Figure 2 shown. Summary of the invention

[0006] The invention provides a GIS switch characteristic measurement auxiliary device, which is used to solve the problem that the RC time constant in the break time measurement loop under certain special working conditions is large, resulting in inaccurate opening waveform and test data measured by an oscilloscope.

[0007] In order to solve the above technical problems, the technical solutions included in the present invention and the beneficial effects corresponding to the technical solutions are as follows:

[0008] The present invention provides a solution of a GIS switch characteristic measurement auxiliary device, comprising a break time measurement circuit, a closing coil current measurement circuit, and an auxiliary switch measurement circuit, wherein the break time measurement circuit, the closing coil current measurement circuit, and the auxiliary switch measurement circuit are all provided with connection points for connecting an oscilloscope, the break time measurement circuit comprises a first resistor and a power supply, and is characterized in that the circuit also comprises an adjustable resistor, and the adjustable resistor is connected in parallel with the first resistor.

[0009] The beneficial effects of the above technical solution are: on the basis of the existing break time measurement circuit, an adjustable resistor is added, and the size of the adjustable resistor can be adjusted according to actual conditions, which can significantly reduce the influence of the RC time constant of the break time measurement circuit, improve the transition phenomenon of the switch break waveform, accurately measure the opening and closing time, improve product detection quality, and improve customer satisfaction.

[0010] Furthermore, the break time measurement loop also includes a second resistor, and the second resistor is connected in parallel at both sides of the GCB break.

[0011] The influence of the RC time constant can be further reduced by adding a second resistor.

[0012] Furthermore, the closing and opening coil current measurement loop is connected to the oscilloscope via a milliohm-level voltage divider resistor, so as to enable the oscilloscope to sample the closing and opening coil control loop current.

[0013] A milliohm-level standard resistor is inserted in series in the opening and closing coil current measurement circuit to sample the opening and closing coil control circuit current with an oscilloscope, which can accurately measure the opening and closing coil circuit current and its waveform and improve the anti-interference ability of the measurement circuit.

[0014] Furthermore, the auxiliary switch measurement circuit is connected to the oscilloscope through a third resistor. A fourth resistor is also provided in the auxiliary switch measurement circuit. The fourth resistor is connected in parallel with the auxiliary switch contact to reduce the influence of the auxiliary switch secondary circuit RC time constant on the auxiliary switch break waveform.

[0015] Furthermore, the power supply includes a battery power supply and a rectifier-step-down module power supply, and the battery power supply and the rectifier-step-down module power supply are controlled by a switching control switch.

[0016] The switching power supply rectifier and step-down module (AC220V to DC5V-24V) makes the power supply easy to obtain and use; the battery power supply is used as a backup power supply, and one of them can be selected according to specific conditions to improve the reliability of power supply.

[0017] Furthermore, it also includes a speed measurement circuit, and the break time measurement circuit, the opening and closing coil current measurement circuit, the auxiliary switch measurement circuit and the speed measurement circuit are all connected to the oscilloscope through terminal block wiring.

[0018] Wiring through terminal blocks makes wiring more convenient, more beautiful, and less prone to errors during the wiring process.

[0019] Furthermore, the terminal block wiring, the first resistor, the second resistor, the adjustable resistor, the milliohm-level voltage divider resistor, the third resistor and the fourth resistor are all arranged in a device box.

[0020] Furthermore, a wiring hole for connecting to an external device is provided on the side of the device box, and an M-shaped strong waterproof cable connector is installed at the wiring hole to prevent moisture and water, prevent the wires from being damaged by friction with the hole wall, and thus protect the wires.

[0021] Furthermore, the adjustable resistor is a knob-type single-turn variable resistor, and the knob portion of the knob-type single-turn variable resistor is arranged on the outer surface of the device box.

[0022] The knob part of the knob-type single-turn rheostat is set on the outer surface of the device box, and the knob is directly rotated during the test, making the operation more convenient.

[0023] Furthermore, the ends of the wires connected to the terminal block are all covered with number tubes, and the purpose of the wire is marked on each number tube to prevent incorrect connection with external wires. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 This is a schematic diagram of a primary main wiring method of the prior art;

[0025] Figure 2 It is a waveform diagram of the opening characteristics of the prior art;

[0026] Figure 3 It is a schematic diagram of a break time measurement circuit of the prior art;

[0027] Figure 4 The present invention increases R L The schematic diagram of the break time measurement circuit after that;

[0028] Figure 5 The present invention increases R1 and R L The schematic diagram of the break time measurement circuit after that;

[0029] Figure 6 This is a comparison chart of the measurement effects of three types of break time measurement circuits;

[0030] Figure 7 It is a schematic diagram of the electrical connection principle of the device of the present invention. DETAILED DESCRIPTION

[0031] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0032] The basic concept of the present invention is: the size of the RC time constant of the measuring loop is changed by the adjustable resistor in the device to improve the waveform of the switch break; the clamp ammeter is replaced by a milliohm-level standard voltage-dividing resistor to sample the current of the opening and closing coil loop by an oscilloscope; the speed measuring line is transitioned and transferred by the device and a signal power supply is provided for it; the action characteristics of the auxiliary switch contact are sampled by the voltage-dividing resistor; the signal power supply (5V to 24V) can be obtained through the reserved interface, and a permanent backup signal power supply (battery box and 9V battery) is also installed to meet the needs of different occasions; the device host adopts an integrated structural design, and the components are encapsulated inside the device box through the internal circuit connection diagram of the device host, and the wires are collected, dispersed and connected in the device box, so that the device is small and portable, easy to use and easy to operate.

[0033] Specifically, the GIS switch characteristic measurement auxiliary device of the present invention comprises a break time measurement circuit for connecting to an oscilloscope, a closing coil current measurement circuit, an auxiliary switch measurement circuit, a speed measurement circuit and a built-in power supply. The present invention improves the break time measurement circuit, the closing coil current measurement circuit, the auxiliary switch measurement circuit and the signal power supply circuit.

[0034] In the existing break time measurement circuit (such as Figure 3 As shown), an adjustable resistor R L (like Figure 4 As shown), the adjustable resistor is connected in parallel with the first resistor R2 in the existing measurement circuit. In the case where there is no break parallel capacitance or the capacitance is very small, R L It can be adjusted to the maximum resistance. When there is a break parallel capacitor or the capacitor is very large, R L It can be adjusted to a smaller value, depending on the actual situation. In order to further reduce the influence of the RC constant and improve the measurement accuracy, the second resistor R1 (such as Figure 5 As shown), the second resistor is connected in parallel on both sides of the GCB fracture, where R1 is a 4.7KΩ resistor; R2 is a 1.0KΩ resistor, and R L The resistance variation range is set to 0.05KΩ~100KΩ. The comparison of the measurement effects of the above three break time measurement circuits is as follows: Figure 6As shown, it can be seen that an adjustable resistor R is added L (like Figure 4 As shown), further, a second resistor R1 is added on this basis (as shown Figure 5 As shown), both solutions can reduce the influence of the RC constant and both solutions are feasible.

[0035] like Figure 7 As shown, a milliohm-level voltage-dividing resistor R is connected in series in the existing opening and closing coil circuit, so as to sample the current of the opening and closing coil control circuit through an oscilloscope, that is, the current waveform is obtained by using the voltage waveform measured in the oscilloscope, or the current in the opening and closing control circuit is converted by Ohm's law using the voltage measured in the oscilloscope; the resistance value of the opening and closing coil circuit current sampling resistor R is 10mΩ or 20mΩ; because the opening and closing coil resistance is generally tens of ohms or larger, and R is in the milliohm level, the voltage division or current limiting problem caused by connecting in series in the circuit can be ignored.

[0036] The auxiliary switch measurement circuit is connected to the measurement channel of the oscilloscope through the third resistor R4. A fourth resistor R3 is added to the existing auxiliary switch measurement circuit. The resistance value of R4 is equal to the resistance value of R2, and the resistance value of R3 is equal to the resistance value of R1. R3 can reduce the influence of the RC time constant of the auxiliary switch secondary circuit (the secondary cable from the control cabinet to the mechanism is generally longer) on the auxiliary switch break waveform.

[0037] The device is equipped with a switching power supply rectifier and voltage reduction module (AC220V to DC5V-24V). The switching power supply module is an AC to DC switching power supply voltage reduction module, which makes the power supply easy to take and easy to use. The DC power supply can power each signal measurement circuit (break time measurement circuit, speed measurement circuit, auxiliary switch measurement circuit). The DC power supply voltage is low and relatively safe; a battery power supply (DC9V) is installed, which is used as a backup power supply for the signal measurement circuit or used under the condition of no power supply (AC220V). In order to further improve the reliability of the characteristic test, the present embodiment is connected to a control switch A on the input side of the switching power supply rectifier and voltage reduction module, and the control switch A can control whether the switching power supply rectifier and voltage reduction module is connected to the AC220V power supply. In addition, a control switch B is connected on the output side of the battery power supply, and the control switch B can control whether each signal measurement circuit is provided with power DC9V by the battery assembly, that is, different power supplies can be selected through the control switch A and the control switch B, wherein the rated voltage of the control switch A is DC / AC220V, and the rated voltage of the control switch B is DC24V.

[0038] The break time measurement circuit, the closing coil current measurement circuit, the auxiliary switch measurement circuit, and the speed measurement circuit are all connected to the oscilloscope through the terminal block wiring. In order to protect the electronic devices from damage, the electronic devices are placed in the device box, and the wires are collected in the device box. Connect the terminal block, the first resistor R2, the second resistor R1, and the adjustable resistor R L , milliohm-level voltage-dividing resistor R, the third resistor R4, and the fourth resistor R3 are all arranged in the device box; a wiring hole for connecting with external equipment is arranged on the side of the device box, and an M-type strong waterproof cable connector is installed at the wiring hole; the adjustable resistor R L It is a knob-type single-turn variable resistor kit, the knob part is installed on the cover of the device box, and the kit is equipped with a resistance value indicating dial; a 9V battery box assembly with a switch and black and red wires is fixed inside or outside the device box; two Φ12mm metal switches are fixed on the cover of the device box; a wire quick connector is installed at the end of each wire, which makes it easy to connect with external wires (external wires are also equipped with wire quick connectors), without exposed terminals, and safe and reliable; the ends of the wires connected to the terminal block are all covered with number tubes, and each number tube is marked with the purpose of the wire to prevent incorrect connection with external wires.

[0039] The specific hardware connection scheme of the GIS switch characteristic measurement auxiliary device of the present invention is as follows:

[0040] (1) Draw a schematic diagram of the electrical connection principle of the device, such as Figure 7 shown.

[0041] (2) Install and fix the terminal block inside the device box.

[0042] (3) According to the schematic diagram of the device's electrical connection principle, connect each resistor to the terminal block in sequence.

[0043] (4) According to the schematic diagram of the electrical connection principle of the device, select and connect the switching power supply rectifier and step-down module on the terminal block.

[0044] (5) Drill three holes on the cover of the device box, two of which are used to install control switches A and B, and the other is used to install the knob-type resistor, and then connect the wires correctly according to the device electrical connection diagram.

[0045] (6) According to the schematic diagram of the electrical connection principle of the device, connect the wires (break wire, speed measurement wire, auxiliary switch measurement wire, coil current measurement wire) to the terminal block.

[0046] (7) Drill several holes on the side of the device box according to the actual wiring needs, and pass the wires on the terminal block (break wire, speed measurement wire, auxiliary switch measurement wire, coil current measurement wire) and the power supply (AC220V) wire led out from the control switch A through each side hole.

[0047] (8) Insert number tubes into each wire passing through each side hole to identify the purpose of the wire, and then connect quick plugs to the ends of each wire.

[0048] (9) Install and fix the battery box assembly inside the device box, and correctly connect the wires to the control switch B according to the device electrical connection diagram.

[0049] (10) After all internal wiring is completed, fasten the terminal block protective cover and install and secure the device box cover.

[0050] (11) According to the number tube markings on the wires, connect the oscilloscope measurement channel wires, the tachometer wires, the break wires on the switch body, the auxiliary switch leads, the closing and opening coil loop leads, and the power cord through the transfer plug at the end of the wires.

[0051] (12) After the above work is completed, the measurement phase can be started. The R can be changed by rotating the rheostat knob on the adjustment device. L The size of the resistor.

[0052] Taking the on-site measurement of circuit breaker switch characteristics in a substation as an example, the detection method of the new device includes the following steps:

[0053] Step 1: After confirming that the primary main circuit test status is correct, remove the ES guide bar at one end of the circuit breaker, connect the port lines A, B, and C from the insulated lead-out of the ES grounding terminal, and connect the port line COM after the ES at the other end of the circuit breaker is grounded; the other end of the above-mentioned broken line is connected to the (A, B, C, COM) line of the new device;

[0054] Step 2: Install a tachometer on the circuit breaker mechanism, and connect the (+, -, C) wires of the tachometer to the (+, -, C) wires of the novel device respectively;

[0055] Step 3: Lead out the auxiliary switch contact leads from the control cabinet, and connect the leads (a, oa) to the (a, oa) lines of the new device respectively;

[0056] Step 4: Disconnect the opening and closing coil control loop and lead out the (+, -) wires, which are respectively connected to the (R+, R-) wires of the new device, that is, connect the milliohm-level standard voltage-dividing resistor R in the new device in series in the opening and closing coil control loop;

[0057] Step 5: Use several oscilloscope channel cables to connect the oscilloscope and the new device according to the corresponding positions;

[0058] Step 6: Confirm that the rheostat knob is at the maximum resistance value of RL, turn on the oscilloscope power, turn on the oscilloscope and set the relevant channel parameters, turn on the signal power (turn on the control switch A or B), trigger the oscilloscope, operate the circuit breaker switch handle on the control cabinet, and then the circuit breaker characteristic test can be carried out;

[0059] Step 7: When the capacitance between the circuit breaker openings is large, the opening waveform of the circuit breaker opening waveform measured will have a transition phenomenon. At this time, the rheostat knob on the rotating device should be appropriately reduced to reduce R L The resistance can be adjusted.

[0060] The main problems solved by the present invention are:

[0061] (1) The device is small in size, light in weight, portable and easy to move.

[0062] (2) When the DL750 oscilloscope is used in conjunction with the control cabinet at the substation to test the opening and closing characteristics of the switch, this device can be used as a special measurement auxiliary device between the DL750 oscilloscope and the break signal line, speed measurement signal line, and auxiliary switch signal line.

[0063] (3) The device is equipped with a milliohm-level standard voltage-dividing resistor, which replaces the commonly used clamp ammeter to perform oscilloscope sampling of the opening and closing coil loop current. It can accurately measure the opening and closing coil current, and its current waveform is not easily affected by external factors.

[0064] (4) For the break time measurement circuit, the device is equipped with R1, R2, R L (Adjustable resistor), through the design of R1, R2 resistance value coordination and R L The resistance adjustment can significantly reduce or eliminate the special main wiring form measurement circuit (such as Figure 1 As shown in the figure, the influence of RC time constant is reduced, thereby improving the transition phenomenon of the switch break waveform (as shown in the figure Figure 2 As shown), the accuracy of the opening and closing time test data is improved, and the test quality is improved.

[0065] (5) The device is equipped with a battery power supply and a rectifier and step-down module power supply, which can be selected for use according to different measurement environments and can provide power supply for all signal measurement circuits in the device.

[0066] The beneficial effects brought by the present invention are:

[0067] (1) It can significantly reduce or eliminate the influence of the RC time constant of the break time measurement circuit, improve the transition phenomenon of the switch break waveform, accurately measure the opening and closing time, improve product testing quality, and improve customer satisfaction.

[0068] (2) It can be used as a transition and measurement auxiliary device between the company's P14 test bench or on-site control cabinet and the DL750 oscilloscope. The device is used for transition and function auxiliary measurement during switch characteristic tests. The secondary wiring is neat and orderly, safe and reliable, with no exposed terminals, which improves test efficiency and safe operation capabilities.

[0069] (3) It can accurately measure the current and waveform of the opening and closing coil circuits, and improve the anti-interference ability of the measurement circuit.

[0070] (4) The device has its own DC power supply or a step-down rectifier function, making it easy to obtain signal power (DC5V-24V).

[0071] (5) Strong practicability and easy to promote and use. The new device has a compact structure, is small and portable, and is easy to move around. It has true and reliable measurements, strong versatility, and high test efficiency. It is suitable for products of various voltage levels and models in the factory, and is suitable for factory tests and on-site tests.

[0072] The specific implementation methods of the present invention are given above, but the present invention is not limited to the described implementation methods. Under the idea given by the present invention, the technical means in the above-mentioned embodiments are transformed, replaced, and modified in a way that is easy for a person skilled in the art to think of, and the effect is basically the same as the corresponding technical means in the present invention, and the purpose of the invention is basically the same. The technical solution formed in this way is formed by fine-tuning the above-mentioned embodiments, and this technical solution still falls within the protection scope of the present invention.

Claims

1. A GIS switch characteristic measurement auxiliary device, comprising a break time measurement circuit, a closing coil current measurement circuit, and an auxiliary switch measurement circuit, wherein the break time measurement circuit, the closing coil current measurement circuit, and the auxiliary switch measurement circuit are all provided with connection points for connecting an oscilloscope, and the break time measurement circuit comprises a first resistor and a power supply, characterized in that: The circuit also includes an adjustable resistor, which is connected in parallel with the first resistor.

2. The GIS switch characteristic measurement auxiliary device according to claim 1, characterized in that: The break time measurement loop also includes a second resistor, which is connected in parallel at both sides of the GCB break.

3. The GIS switch characteristic measurement auxiliary device according to claim 2, characterized in that: The closing and opening coil current measurement loop is connected to the oscilloscope through a milliohm-level voltage divider resistor to enable the oscilloscope to sample the closing and opening coil control loop current.

4. The GIS switch characteristic measurement auxiliary device according to claim 3, characterized in that: The auxiliary switch measurement loop is connected to the oscilloscope through a third resistor. A fourth resistor is also provided in the auxiliary switch measurement loop. The fourth resistor is connected in parallel with the auxiliary switch contact to reduce the influence of the auxiliary switch secondary loop RC time constant on the auxiliary switch break waveform.

5. The GIS switch characteristic measurement auxiliary device according to claim 1, characterized in that: The power supply includes a battery power supply and a rectifier-step-down module power supply, and the battery power supply and the rectifier-step-down module power supply are controlled by a switching control switch.

6. The GIS switch characteristic measurement auxiliary device according to claim 4, characterized in that: It also includes a speed measurement circuit, and the break time measurement circuit, the opening and closing coil current measurement circuit, the auxiliary switch measurement circuit and the speed measurement circuit are all connected to the oscilloscope through terminal block wiring.

7. The GIS switch characteristic measurement auxiliary device according to claim 6, characterized in that: The terminal block wiring, the first resistor, the second resistor, the adjustable resistor, the milliohm-level voltage-dividing resistor, the third resistor and the fourth resistor are all arranged in the device box.

8. The GIS switch characteristic measurement auxiliary device according to claim 7, characterized in that: The side of the device box is provided with a wiring hole for connecting with external equipment, and an M-type strong waterproof cable connector is installed at the wiring hole.

9. The GIS switch characteristic measurement auxiliary device according to claim 7, characterized in that: The adjustable resistor is a knob-type single-turn variable resistor, and the knob part of the knob-type single-turn variable resistor is arranged on the outer surface of the device box.

10. The GIS switch characteristic measurement auxiliary device according to claim 6, characterized in that: The ends of the wires connected to the terminal block wiring are all covered with number tubes, and the purpose of the wire is marked on each number tube to prevent incorrect connection with external wires.

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