CN104007294B - Overhead line parameter measurement wiring device - Google Patents

Abstract

The invention discloses a wiring device for measuring overhead line parameters. The device includes a three-phase high-voltage lead wire interface, a main switching switch, three induced voltage measuring pile heads, three AC voltmeters, a DC voltmeter, and a DC voltmeter. Ammeter, three air switches, and a rectifier. The three-phase high-voltage lead wire interface is located on the rear side of the box for the introduction of overhead lines; the main switch is located above the device panel to realize the switching of the overhead line induced voltage and DC resistance parameter measurement functions; the induced voltage leads to the measurement pile head on the left side of the device It can be connected with an external instrument to realize the measurement function; the AC voltmeter is used to measure the induced voltage; the DC voltmeter and the DC ammeter are used to measure the voltage and current in the DC resistance measurement circuit; the air switch realizes the selection of the DC measurement circuit; the rectifier device realizes the AC DC conversion is used to complete DC resistance measurement. The invention can solve the troublesome problem of connecting and changing wires in the prior art.

Description

Wiring device for overhead line parameter measurement

Technical field:

The invention relates to a wiring device for measuring overhead line parameters.

Background technique:

Before the newly-built and rebuilt high-voltage overhead lines are put into use, it is necessary to check the line insulation, check the phase, measure the DC resistance and various power frequency parameters, and use them as calculation system short-circuit current, calculation power flow distribution, relay protection setting and reasonable operation The actual basis of the choice of the method and other work.

In the prior art, testers generally use manual wiring to realize the connection between the test equipment and the transmission line under test. In the current overhead line parameter test project, the operation of connecting and changing lines in the measurement links of induced voltage, nuclear phase, insulation resistance and DC resistance is too cumbersome:

Before wiring, the testers at the first and last ends of the overhead line should first close the grounding knife respectively, then use high-altitude wiring pliers to hook up the bare copper wire, and then tighten and fix it with insulating tape to prepare for the test. In order to ensure the personal safety of the testers, To prevent the induction electric injury, insulated gloves should be worn during the whole test wiring process.

When measuring the induced voltage, it is required to short-circuit the non-measuring phase to ground at the end first, and suspend the phase to be measured; the three phases at the first end are all suspended in the air, and then the first and last ends pull the grounding knife, and the testers at the first end start to use a multimeter to lap the three phases in turn. Measure the induced voltage and check the phases, and then use the insulation resistance meter to measure the insulation resistance of the three phases. After the above test process is completed, the induced voltage and insulation resistance measurement of one phase is completed. During the measurement process, it can be checked at the same time whether the phase differences between the first and last ends of the phase are corresponding. After the one-phase test is completed, it is necessary to contact the tester at the end of the line to replace the wiring. At this time, the tester at the end will usually close the grounding switch again, and then change the line and repeat the above test operation. After the three-phase test is completed, close the grounding switch at the first and last ends again to prepare for the DC resistance test.

When measuring DC resistance, the test personnel at the end of the line are required to short-circuit the three phases without grounding; the test personnel at the head end connect the two phases to be measured in series into the DC circuit. The DC circuit is generally connected in series by two vehicle batteries as the power supply, and then a pointer ammeter is connected in series with a pointer ammeter from one end of the power supply to measure the current in the circuit, and then the two phases to be measured (shorted at the end) are connected in series Enter the DC circuit, and finally connect it to the other pole of the battery pack with a wire (reconnect when starting the test) to form a DC test circuit. The DC circuit cannot be closed before the test. During the test, the grounding switch should be opened at the first and last ends. A tester at the first end will manually connect the battery to form a DC circuit during the test. It can be regarded as a switch for the DC circuit. One tester is responsible for connecting the multimeter to the two poles of the battery pack to read the circuit voltage, and one tester is responsible for reading the readings of the ammeter in the circuit, and the tester responsible for recording must record the read test voltage and current values in time. After the above tests are completed, the first-end test personnel close the grounding switch, replace the test wiring, and measure the voltage and current values of the other two phases according to the above steps. After the three sets of tests are completed, close the grounding switch at the first and last ends. , the DC resistance test ends.

The operation of connecting and changing the wires described above is complicated, and the tester needs to directly touch the test wires when wiring. When the power frequency induced voltage in the transmission line under test is low, it will cause a slight electric shock to the test personnel. However, when the power frequency induced voltage is high, it will seriously injure the test personnel, and even cause the death of the test personnel.

Although in the prior art, it is possible to use insulating gloves for wiring to ensure the personal safety of the test personnel. However, insulating gloves are generally relatively thick, and it is very inconvenient for testers to wear insulating gloves for wiring, which can easily lead to loose wiring and affect the test process and test accuracy.

Invention content:

In order to overcome the defects of the prior art, the object of the present invention is to provide a wiring device for measuring overhead line parameters, which can solve the cumbersome problem of connecting and changing lines in the prior art. At the same time, it can realize the effective isolation between the test personnel and the charged body during the test, so as to ensure the personal safety of the test personnel.

The present invention solves technical problem and adopts following technical scheme:

The overhead line parameter measurement wiring device is provided with a junction box as the main body of the wiring device, a three-phase high-voltage lead wire interface is provided on the side of the junction box, and an induced voltage is provided on the other side to lead out the measurement pile head;

A main switch is arranged on the panel of the junction box. The main switch has a disc-shaped switch base and a switch knob that can rotate on the switch base. Contacts, each group of static contacts includes five fixed contacts arranged at equal intervals; the switch knob is provided with three sliders corresponding to the three groups of static contacts at intervals, and each of the sliders can and Can only be in contact with three of the fixed contacts at the same time;

There are also three AC voltmeters, a DC voltmeter, a DC ammeter, three air switches and a rectifier on the junction box panel; the three-phase high-voltage wire of the overhead line is connected to the junction box through the three-phase high-voltage lead interface, and The third fixed contact of each group of static contacts is connected; the fifth fixed contact of each group of static contacts is respectively connected to the three AC voltmeters through the lead wires, and the three induced voltages lead to the measurement pile heads with the lead wires respectively. The fifth fixed contact connection of each set of static contacts;

The DC voltmeter and DC ammeter are connected in the DC circuit transformed by the rectifier device, and the two lines of the DC circuit are connected in parallel to the three air switches. Among the three sets of static contacts on the switch base, the first The first fixed contact of the second group of static contacts is connected to the first air switch, the first fixed contact of the second and third group of static contacts is connected to the second air switch, and the third fixed contact of the first group of static contacts is connected to the second air switch. The first fixed contact is connected with the third air switch.

The three-phase high-voltage lead wire interface is located on the rear side of the junction box for the introduction of overhead lines; the main switch is located on the device panel to realize the switching of the overhead line induced voltage and DC resistance parameter measurement functions; the induced voltage leads the measurement pile head to the wiring On the left side of the box, an external instrument can be connected to realize the measurement function; the AC voltmeter is used to measure the induced voltage; the DC voltmeter and the DC ammeter are used to measure the voltage and current in the DC resistance measurement circuit; the air switch realizes the selection of the DC measurement circuit; The rectification device realizes the conversion of AC and DC to complete the measurement of DC resistance.

Compared with the prior art, the beneficial effects of the present invention are reflected in:

The present invention can select the corresponding measurement function through the main switch, simplifies the frequency of manual connection and replacement in the test process, and solves the problem of complicated connection and replacement in the prior art. At the same time, all the line switching operations of the present invention are completed in the overhead line parameter measurement wiring device, which realizes the isolation of the tester and the charged body during the test process, and can effectively guarantee the personal safety of the tester.

Description of drawings:

Fig. 1 is a perspective view of the device of the present invention; Fig. 2 is a schematic block diagram of a main switch; Fig. 3 is a schematic diagram of a switch knob of a main switch; Fig. 4 is an internal circuit diagram of the present invention.

Labels in the figure: 1 Junction box, 2 Three-phase high-voltage lead wire interface, 3 Induction voltage leads to measuring pile head, 4 Main switch, 5 Switch knob, 6 Switch base, 7 Slider, 8 AC voltmeter, 9 DC voltmeter , 10 DC ammeter, 11 first air switch, 12 second air switch, 13 third air switch.

The present invention will be further described below through specific embodiments and in conjunction with the accompanying drawings.

detailed description:

Embodiment: In combination with Fig. 1, a junction box 1 as the wiring device body is provided, and three holes are provided on the rear side of the junction box 1 as the three-phase high-voltage lead wire interface 2, and three holes are provided on the other side (left side) of the junction box. An induced voltage leads to the measurement pile head 3;

The junction box panel is provided with a main switch 4, as shown in Figures 2 and 3, the main switch has a disc-shaped switch base 6 and a switch knob 5 that can rotate on the switch base. There are three groups of static contacts distributed at intervals in the circumferential direction, and each group of static contacts contains five fixed contacts arranged at equal intervals; the three groups of static contacts are respectively numbered as group I, group II and group III, each group of static contacts The five fixed contacts of the contact are respectively numbered ①②③④⑤, and the fixed contacts numbered ② and ④ in each group are neutral gears. Three sliders 7 corresponding to the three groups of static contacts are arranged at intervals on the switch knob. It can and can only be in contact with three fixed contacts at the same time, that is, the three sliders can respectively conduct the fixed contacts ① and ③ or the fixed contacts ③ and ⑤ of the three sets of static contacts.

There are also three AC voltmeters 8, a DC voltmeter 9, a DC ammeter 10, three air switches and a rectifier on the junction box panel; the three-phase high-voltage wires of the overhead line are connected to the junction box through the three-phase high-voltage lead interface 2 1. Connect with the third fixed contact (number ③) of each set of static contacts; the fifth fixed contact (number ⑤) of each set of static contacts is respectively connected to three AC voltmeters via lead wires, on the left side of the junction box The three induced voltages lead to the measurement pile head 3 and are respectively connected to the fifth fixed contact (number ⑤) of each group of static contacts through lead wires.

As shown in Figures 2 and 4, the DC voltmeter 9 and the DC ammeter 10 are connected in the DC circuit converted by the rectifier device, the two lines of the DC circuit are connected in parallel on three air switches, and the three sets of static contacts of the switch base 6 , the first fixed contact (number ①) of the static contact of group I and II is connected to the first air switch 11, and the first fixed contact (number ①) of the static contact of group II and III is connected to the second air switch 12 connection, the first fixed contact (number ①) of the third third group I static contact is connected with the third air switch 13.

As shown in Figure 3, the realization principle of the main switch of the present invention is analyzed in combination with the above-mentioned content: when the switch knob is in the X gear, the three sliders 7 are respectively on the ②③④ fixed contacts of each group of static contacts, and they are in neutral at this time state; when the switch knob is turned to the Y gear, the three sliders 7 slide synchronously to the ①②③ fixed contacts of each group of static contacts to realize the ①③ conduction; when the switch knob is turned to the Z gear, the three sliders 7 Synchronously slide to the ③④⑤ fixed contacts of each group of static contacts to realize ③⑤ conduction;

Working process of the present invention is as follows:

Preparations before the test: First, close the grounding switches at both ends of the overhead line to be tested, and then use high-altitude wiring pliers to hang the bare copper wires at the first and last ends of the overhead line to lead the three phases down and fix them on the insulating tape (keep lead wires are insulated from each other). Then lead the lead wire at the head end of the overhead line into the measuring wiring device, and the A, B, and C three-phase lines are respectively connected to the third fixed contacts (number ③) of the three sets of static contacts.

At the beginning of the test, first measure the induced voltage (phase nuclear can also be realized at the same time), at this time, the A phase at the end of the overhead line to be tested should be suspended, and the two phases B and C should be short-circuited to the ground; after the above process is completed, the first and last ends of the overhead line Pull open the ground switch, turn the main switch knob of the device to the Z position, and read the three-phase induced voltage through three AC voltmeters (at this time, it is actually measuring the induced voltage of line A, the reason for reading the three-phase voltage is mainly It is for comparison with the voltage value of phase A. Since the ends of the phase B and C lines have been grounded, the measured voltages of B and C should be much smaller than the voltage measured by phase A, thus realizing the nuclear phase of the line, that is, the A phase at the head end. Phase corresponds to phase A at the end), after measuring the induced voltage of phase A, the insulation resistance of the three phases can be measured through the induced voltage on the left side of the junction box by leading out the measuring pile head (measured by an external megohmmeter). The insulation resistance values of phase B and phase C should also be smaller than that of phase A, thus reconfirming the phase sequence correspondence between the first and last ends. The data recorded in the test is only the induced voltage value and insulation resistance value of the measured phase (A phase), and whether the phases at the first and last ends correspond to each other. After the completion, turn the knob of the main switch to neutral, and then contact the personnel at the end of the overhead line to short-circuit the ends A and C to ground, and suspend phase B. Repeat the above steps to complete the measurement of the induced voltage of phase B. The measurement operation of phase C is the same.

After the induced voltage measurement is completed, the three phases at the end of the overhead line need to be short-circuited and not grounded. Then the head-end tester turns the main switch knob of the device to the Y position to measure the DC resistance. First, close the first air switch (AB air switch) open), read the voltage and current of the AB DC circuit, then disconnect the AB air switch, and then close the second air switch (BC air switch), read the voltage and current of the BC DC circuit, and then close the third air switch Switch (CA circuit breaker), read the voltage and current of CA DC circuit.

The use of the device ends here, the head end closes the ground switch knife, and the device is taken off.

Claims (1)

1. overhead transmission line parameter measurement termination is it is characterised in that be provided as the junction box (1) of termination body, It is provided with three-phase high-voltage pin interfaces (2) in the side of described junction box, another side is provided with induced voltage and draws measurement pile crown (3)；

Junction box's panel is provided with main switching switch (4), described main switching switch have discoidal switch base (6) and The switching knob (5) that can rotate in switch base, circumferentially spaced in described switch base three group static contacts are distributed with, Every group of static contact comprises five fixed contacts equidistantly arranged；It is interval with described switching knob and described three groups of static contacts pair Three slide blocks (7) answered, each described slide block energy and can only simultaneously contacting with three described fixed contacts；

Three A.C. voltmeters (8), D.C. voltmeter (9), a DC ammeter are additionally provided with junction box's panel (10), three air switches and a fairing；Overhead transmission line three-phase high-voltage line is through described three-phase high-voltage pin interfaces (2) Access junction box (1), be connected with the 3rd fixed contact of every group of static contact respectively；5th fixed contact of every group of static contact is through lead Connect described three A.C. voltmeters respectively, three described induced voltages extraction measurement pile crown (3) are quiet with every group respectively through lead 5th fixed contact of contact connects；

Described D.C. voltmeter (9), DC ammeter (10) are connected in the DC loop of described fairing conversion, institute The two lines road stating DC loop is connected in parallel on described three air switches, in three groups of static contacts of switch base, the one the second First fixed contact of group static contact is connected with the first air switch, the first fixed contact of the two or three group of static contact and the second air Switch connects, and the first fixed contact of the 3rd the first static contact is connected with the 3rd air switch.