CN106226564B - Routine test transfer box for high-voltage capacitive voltage transformer without removing the lead wire - Google Patents

Abstract

The invention discloses a routine test transfer box of a high-voltage capacitor type voltage transformer without removing lead wires, and relates to the technical field of power voltage transformer tests. The transition box includes a box body and a main panel on the upper surface of the box body. The equipment terminal of the main panel is connected to the device under test through insulated wires, and the instrument terminal is connected to the tester through the test line provided by the tester itself. The changeover switch in the operating area of the main panel can switch the wire connection mode in the inner space of the box body, so as to realize the purpose of completing the two test modes without disconnecting the wires. The transfer box is convenient to carry, easy to operate, reliable and safe, thereby reducing the number of climbing and wiring times of operators, and improving the efficiency of CVT routine tests.

Description

Routine test transfer box for high-voltage capacitive voltage transformer without removing the lead wire

technical field

The invention relates to the technical field of power voltage transformer testing.

Background technique

Traditional electromagnetic voltage transformers in power systems with a voltage level of 110kV and above are prone to resonant overvoltages with circuit breaker fracture equalizing capacitors. Therefore, capacitive voltage transformers (CVT ). The working principle of the capacitive voltage transformer is to divide the voltage by the series capacitor first, and then step down and isolate it through the electromagnetic voltage transformer. In order to ensure the safe and normal operation of the CVT, routine tests are carried out on a regular basis. There are two main routine test items, namely, the measurement of the insulation resistance of each internal part and the measurement of the capacitance and dielectric loss. The measurement of capacitance and dielectric loss is one of the important parameters to judge the insulation state of CVT. It can effectively reflect a series of defects such as water ingress and moisture in the equipment, insulation aging, etc. Since the CVT has both a capacitive voltage divider unit and an electromagnetic unit, the structure is complex, which determines that the measurement of the CVT capacitance and dielectric loss needs to be carried out in two steps.

At the substation test site, a tester needs to wear a safety belt to climb up the ladder, hang the safety belt hook or rope on the CVT support structure, remove the CVT secondary panel and test the wiring, and wait for the operator to get off the ladder and move to a safe position Do the first step of the test. After the first step of the test is completed, the operator needs to go up the ladder again to switch the test line. After the operation is completed, get off the ladder to carry out the second step of the test. After the second step is completed, the climber needs to go up the ladder again to remove the test wiring and restore the CVT secondary panel to its original state.

The operators in the first and second steps of the test steps need to climb up the ladder, fix the safety belt, and switch the test wiring. In addition, according to the relevant regulations, one person must climb up and one person should climb up the escalator when using a ladder to climb up. Therefore, the efficiency of CVT routine test is low at present, which affects the overall routine test work progress of the substation.

Contents of the invention

The technical problem to be solved by the present invention is to provide a routine test adapter box for high-voltage capacitive voltage transformers without removing the lead wires. The adapter box has the advantages of easy portability, simple operation, reliability and safety. Thereby reducing the climbing and wiring times of operators and improving the efficiency of CVT routine tests.

In order to solve the above technical problems, the technical solution adopted by the present invention is: a high-voltage capacitive voltage transformer routine test transfer box without removing the lead wire method, which is characterized in that the transfer box includes a box body and a main panel, the box The body is made of insulating material;

The main panel is provided with three areas: an operation area, an equipment area and an instrument area; the operation area includes an AC ammeter and a changeover switch for switching the internal connection mode of the box; The four equipment terminals are respectively the first equipment terminal, the second equipment terminal, the third equipment terminal and the fourth equipment terminal; the instrument area is provided with four instrument terminals for connecting test instruments , are respectively the terminal of the first instrument, the terminal of the second instrument, the terminal of the third instrument and the terminal of the fourth instrument;

The inner space of the box body is provided with wires for connecting equipment terminal, instrument terminal, AC ammeter and transfer switch: the first instrument terminal is connected with the first equipment terminal, the second instrument terminal is connected with the AC ammeter One end is connected, the other end of the AC ammeter is connected to the terminal of the third equipment, and the terminal of the third instrument is connected to the terminal of the fourth equipment;

The conversion switch includes a first gear, a second gear and a third gear, the first gear connects the first equipment terminal with the second equipment terminal; the second gear connects the second equipment terminal with the second equipment terminal The fourth instrument terminal is connected; the third gear is the closed gear.

Preferably, the high voltage is greater than or equal to 220kV.

Preferably, the withstand voltage level of the equipment terminal and the instrument terminal reaches 3kV; the withstand voltage level of the wire connected to the first instrument terminal and the first equipment terminal reaches 3kV; the first equipment terminal and the The withstand voltage level of the wire connected to the terminal of the second equipment reaches 3kV.

Preferably, the AC ammeter is a mechanical pointer type with a range of 50A.

The beneficial effect produced by adopting the above-mentioned technical scheme is that: the equipment terminal of the main panel is connected with the equipment under test through the insulated wire, and the instrument terminal is connected with the tester through the supporting test line of the tester itself. The transfer switch in the operating area of the main panel can change the wire connection mode in the inner space of the box body, so as to realize the purpose of completing two test modes without disconnecting the wires. The transfer box is easy to carry, easy to operate, practical and safe, reduces the number of times the test personnel climb up the ladder and connects, optimizes the entire test process, and improves the efficiency of the CVT routine test.

Description of drawings

Fig. 1 is a schematic structural view of the main panel on the upper surface of the box body of a specific embodiment of the present invention;

Fig. 2 is a schematic diagram of the wire connection method in the inner space of the box body of the embodiment in Fig. 1 .

In the figure: 1. Operation area; 2. Equipment area; 3. Instrument area; 4. AC ammeter; 5. Transfer switch; 51. First gear; 52. Second gear; 53. Third gear; 6 , equipment terminal; 61, first equipment terminal; 62, second equipment terminal; 63, third equipment terminal; 64, fourth equipment terminal; 7, instrument terminal; 71, first instrument terminal ; 72, the terminal of the second instrument; 73, the terminal of the third instrument; 74, the terminal of the fourth instrument.

Detailed ways

In order to make the object, technical solution and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, not to limit the present invention.

As shown in Fig. 1, it is an embodiment of the junction box for the routine test of the high-voltage capacitive voltage transformer of the present invention without removing the leads. In this embodiment, the transition box includes a box body and a main panel, and the box body is made of insulating material. The main panel has three areas: operation area 1, equipment area 2 and instrument area 3. The operation area 1 includes an AC ammeter 4 and a changeover switch 5 for switching the internal connection mode of the box body. In the equipment area 2, there are four equipment terminals 6 for connecting the equipment under test, which are respectively the first equipment terminal 61, the second equipment terminal 62, the third equipment terminal 63 and the fourth equipment terminal 64; There are four instrument terminals for connecting test instruments in the area, namely the first instrument terminal 71 , the second instrument terminal 72 , the third instrument terminal 73 and the fourth instrument terminal 74 .

In one embodiment, the box body is a hollow cuboid, and six sides are insulators. As shown in Figure 1, there are four equipment terminals 6 in the equipment area 2 on the left side of the main panel. The same-named ends of the secondary terminals of the equipment are connected. There are four instrument terminals 7 in the equipment area 3 on the right side of the main panel. The names are respectively "Cx", "CVT+", "CVT-" and the ground terminal. When using it, the test line and the same name as the tester are used. The terminals are connected. The withstand voltage level of the terminal 6 of the equipment and the terminal 7 of the instrument area reaches 3kV, and all the eight terminals are required to be conventional terminals that can withstand 3kV AC voltage for a long time. The AC ammeter 4 in the operation area 1 of the main panel is a mechanical pointer type with a range of 50A, which is used to monitor the current situation of the wire during the second step test, in order to avoid burning the test instrument due to excessive current during the second step test. The transition box is especially suitable for routine tests of capacitive voltage transformers with power line voltage levels of 220kV, 330kV, 500kV, etc. of 220kV and above.

As shown in FIG. 2 , it is the wire connection method in the inner space of the box body of the embodiment in FIG. 1 . The wire connection mode of the inner space of the box body is that the first instrument terminal 71 is connected with the first equipment terminal 61; the second instrument terminal 72 is connected with one end of the AC ammeter, and the other end of the AC ammeter is connected with the third equipment. The posts 63 are connected; the third instrument terminal 73 and the fourth equipment terminal 64 are connected. Wherein, the withstand voltage level of the wires between the first instrument terminal 71 and the first equipment terminal 61 reaches 3 kV on average. The average withstand voltage level of the wires between the first device terminal 61 and the second device terminal 62 reaches 3kV. The rest of the internal wires are ordinary insulated wires. The AC ammeter 4 is connected in series between the "da" terminal and the "CVT+" terminal.

The transfer switch 5 used to switch the internal connection mode of the box body includes a first gear 51, a second gear 52 and a third gear 53, and the first gear 51 connects the first equipment terminal 61 and the second equipment terminal 62 connected. The second gear 52 connects the second equipment terminal 62 and the fourth instrument terminal 74 . The third gear 53 is a closed gear. As shown in Figure 2, the names of the three gear positions of the transfer switch 5 are respectively "A" gear 51, "B" gear 52 and "OFF" gear 53, which are used to realize the wiring conversion between the two test steps: when the transfer switch 5. When switching to the "A" gear 51, the first step of the test "shielding method" test can be carried out; when the transfer switch 5 is switched to the "B" gear 52, the second step of the test "self-excitation method" test can be carried out; When the transfer switch 5 is switched to the "OFF" gear 53, no test is performed.

At the routine test site of the high-voltage CVT in the substation, the test personnel first climbed up the ladder, removed the CVT secondary panel, and connected all the secondary terminals used in the test to the test transfer box safely and firmly with custom-made leads. Equipment area 2. Connect the tester to the instrument area 3 of the adapter box with the test line provided with the tester itself. The knob of the transfer switch 5 is switched from the "OFF" gear 53 to the "A" gear 51, and the first step of the test is carried out. After completion, switch the knob of changeover switch 5 from "A" gear 51 to "B" gear 52, and carry out the second step test of the test. Finally, switch the knob of the transfer switch 5 from the "B" position 52 to the "OFF" position 53, remove the connection between the conversion box and the CVT and the connection between the conversion box and the test instrument, and the tester goes up the ladder to restore the CVT for the second time. Panel to the initial state, complete the entire test.

The beneficial effect produced by adopting the above-mentioned technical scheme is that: the equipment terminal of the main panel is connected with the equipment under test through the insulated wire, and the instrument terminal is connected with the tester through the supporting test line of the tester itself. The transfer switch in the operating area of the main panel can change the wire connection mode in the inner space of the box body, so as to realize the purpose of completing two test modes without disconnecting the wires. The transfer box is easy to carry, easy to operate, practical and safe, reduces the number of times the experimenter climbs up the ladder and connects, optimizes the entire test process, and improves the efficiency of the CVT routine test.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements and improvements made within the spirit and principles of the present invention should be included in the protection of the present invention. within range.

Claims (3)

1. The high-voltage capacitance type voltage transformer routine test switching box is characterized by comprising a box body and a main panel, wherein the box body is made of insulating materials;

the main panel is provided with three areas, namely an operation area (1), an equipment area (2) and an instrument area (3); the operation area (1) comprises an alternating current ammeter (4) and a change-over switch (5) for switching the connection mode in the box body; four device binding posts (6) for connecting tested devices are arranged in the device area (2), namely a first device binding post (61), a second device binding post (62), a third device binding post (63) and a fourth device binding post (64); four instrument binding posts (7) for connecting a testing instrument are arranged in the instrument area (3), namely a first instrument binding post (71), a second instrument binding post (72), a third instrument binding post (73) and a fourth instrument binding post (74); the names of the first equipment binding post (61), the second equipment binding post (62), the third equipment binding post (63) and the fourth equipment binding post (64) are respectively N, X, da and dn in sequence, and are respectively connected with the same name end of the secondary terminal of the tested equipment by insulated wires when in use; the names of the first instrument binding post (71), the second instrument binding post (72), the third instrument binding post (73) and the fourth instrument binding post (74) are respectively Cx, CVT+, "CVT-" and a grounding end in sequence, and the first instrument binding post, the second instrument binding post (72), the third instrument binding post and the fourth instrument binding post (74) are connected with terminals with the same name as the testing instrument through test wires matched with the testing instrument during use;

the inner space of the box body is provided with a wire for connecting the equipment binding post (6), the instrument binding post (7), the alternating current ammeter (4) and the change-over switch (5): the first instrument binding post (71) is connected with the first equipment binding post (61), the second instrument binding post (72) is connected with one end of the alternating current ammeter (4), the other end of the alternating current ammeter (4) is connected with the third equipment binding post (63), and the third instrument binding post (73) is connected with the fourth equipment binding post (64);

the change-over switch (5) comprises a first gear (51), a second gear (52) and a third gear (53), wherein the first gear (51) connects a first equipment binding post (61) and a second equipment binding post (62); a second gear (52) connects the second device terminal (62) and the fourth instrument terminal (74); the third gear (53) is a closing gear;

the voltage withstand level of the equipment binding post (6) and the instrument binding post (7) reaches 3kV; the voltage withstand level of the lead wire connected with the first instrument binding post (71) and the first equipment binding post (61) reaches 3kV; the voltage withstand level of the lead wire connected with the first equipment binding post (61) and the second equipment binding post (62) reaches 3kV.

2. The high voltage capacitive voltage transformer no-lead disassembly routine test transfer box of claim 1, wherein the high voltage is 220kV or more.

3. The high-voltage capacitive voltage transformer routine test switching box without disassembling leads according to claim 1, wherein the alternating current meter (4) is a mechanical pointer type, and the measuring range is 50A.

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