JPS5890181A - Phase detector for specially-high voltage - Google Patents

Abstract

PURPOSE:To increase the safety of operations and to enable the sure detection of a phase in a short time, by detecting the phase through comparison of current values generated by the phase difference of the electrostatic induction voltage of each phase of the main circuit. CONSTITUTION:After the sizes of retaining rods 13 and 14 are fixed in safe lengths, detectors 11 and 12 are fitted to the respective ends of the rods, and they are arranged and retained manually below the main circuit whose phase is to be detected, respectively. In addition, the detectors 11 and 12 detect an electrostatic induction voltage from each phase of a line switch 31, and microvoltages thus detected are led to an ammeter 17 via shield cables 15 and 16. The ammeter 17 measures a current generated by the phase difference of the microvoltages which are led therein.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a special high-voltage phase detector suitable for phase verification tests of electric power systems such as, for example, fat line switches.

As is well known, after starting 14L F') f, constructing or expanding a substation, changing capacity, pulling out transmission lines, replacing equipment, or performing temporary equipment construction, a phase detection test is required for connection N and candy. is necessary. Recently, there have been many construction projects of this type, and opportunities for phase verification tests have also increased.

Generally, in phase detection of a 6,000-inch circuit, primary phase detection can be performed relatively easily using a commercially available high-voltage phase detector used in power distribution lines, etc. However, due to the circuit voltage exceeding 60,000 V and safety issues, primary phase detectors have not yet been developed.

Conventionally, the phase detection methods for special high voltage circuits include (1) secondary phase detection using an instrument transformer, (2) megger phase detection using an insulation resistor (megger), and (3) provisional phase detection. There is secondary phase detection performed via a designer transformer.

However, secondary phase inspection requires a limited number of locations for phase inspection, requires complicated system operations due to large-scale system changes, and takes a long time. In addition, when installing a temporary single-unit transformer, construction costs increase, and if it is difficult to stop the transmission N line, the work must be done on or near live lines, making the work complicated and dangerous. There is a point where the number of elements increases. For this reason, there is a strong need for the development of a primary phase detector that can perform phase detection directly from the main circuit, rather than indirect secondary phase detection using a voltage transformer.

This invention was made based on the above circumstances, and its purpose is to detect the voltage of the Seidenbo 4 from each phase of the main circuit using a detector with a simple configuration, and to calculate the current value generated by the phase point of this voltage. Compared to secondary phase detection using an instrument transformer, phase detection can be performed reliably in a shorter period of time [1] than by secondary phase detection using a voltage transformer. The purpose of this invention is to provide a high-voltage phase detector that can safely determine whether work is being done without coming into contact with the equipment.

Hereinafter, one embodiment of the present invention will be described with reference to the drawings.

In FIG. 1, 11. Detectors J2 each have the same shape, and these detectors 11 and 12 are constructed of, for example, 8-piece aluminum Zeig. That is, this detector J
J, 12 are rectangular outer frames JJ1. J2 (and the inner frame 112°123 and this outer frame horn 1+721.
Connection member 713 that connects the inner frames 112r122 within a plane 1J74 1J11I +Jl@ +J2
A circular attachment portion J1r+127 is provided at the intersection of the connecting members 113-116 and 12s-26. FIG. 2 shows the detector 1 taken out, and shows the outer frame 11. , dimension t1 of the inner frame 113 ・Lx +t3 rL<Id,
For example, L I = 500 m.

Lz=300m, t3=300++un, L4=200
+n. This detector IJ, 12 mounting part J17*
Holding rods 13 and 14 made of, for example, an insulating member for extra-high voltage detectors are detachably attached to each of the holding rods 127. moreover,
One end (core wire) of a shielded cable 15°J6 is attached to the attachment portion jll+121 of the detector 11.12. The other end of the aluminum 5176 (core wire and shield couple) is connected to the connection terminals 171+172 of the ammeter (microammeter) 17. 173° and 174, respectively, and the grounding terminal J7 of this current 1J7.
A lead 781B is connected to.

In the above configuration, for actual measurement, first fix the length of the holding rod J3.14 to a safe length (below the height of the equipment pedestal), and then attach the detector I to the tip of the holding rod 13.14.
J, 12 is attached. As shown in FIG. 3, the detectors 11*12 are manually placed and held under the main circuit (eg, line switch 9J) for phase detection. This detector jl*12 detects the static conduction voltage from each phase of the line switch 3, and this detected minute voltage is transmitted to the shielded cable J5. It is led to the ammeter 17 via J6.

This 1m current meter 17 measures the current generated by the phase difference of the introduced minute voltage, and this current value is displayed. Such measurements are performed for each of the R phase, S phase, and T phase of the line switch 3 shown in FIG.

Next, the measurement principle will be explained. As shown in Figure 5,
A plurality of point charges Q+ +Qa in a vacuum, the potential 9 at a point P located a distance r1 +r2 +rB away from Qs (where ε0 is the dielectric constant of the vacuum) becomes 5-.

In addition, as shown in Fig. 6, iIt of finite length t in vacuum
The electric potential at point P generated by electric charges (density q) evenly distributed in the rice grains is xl-I-i!, where the vertical distance between the wire and point P is 81, and the cross-sectional area of the wire is a. becomes.

Furthermore, the electric potential at point P caused by charges (density ql + 9g + q3...) uniformly existing in a plurality of electric wires of finite length in the air X is given by equation (2).

Using the above equations (1) to (3), we will calculate the potential directly below the wires of a three-phase AC circuit at an electric station.

As shown in FIG.
If the distance between I, +QL and Pl is S+Z, and the length of the line is L)rL2, then 〆Sth 2 +, r,.

becomes. Here, taking the case of a 66 kV disconnector as an example, 5II=1 m, L1== (1,5y(, S
st=6 m.

ta = 1 m. Substituting this into the above formula yields =,
ql 'X 1.113.

Also, the potential of 21 points "11" generated by q2 and -92 is as follows. Here, S 2J = 1.8 m, 11 =
(1.5m.

If we set 5zz=6.2 m and 12=1 m, the above equation becomes = Ih Qa Xo, 564.

Also, the 21-point electric current fX'L?
' r s is (〆Ss +2+Lr2-2+X〆Ss z2+1*2
+1g). Here, 5s17” 3.2m, A
l=0.5m.

9-53a=6.7m and t2=lm, the above equation becomes "'Ks qs Xo, 24".

Ql + Ql +q* +-q2 +ql
The potential ■1 at 21 points generated by l qs is V+ = t'st + V + z + t'ts = Kg (Ql X 1.113 + qaX0.564 +
qsX0.243), and this Ql +qa l
If q8 is applied to a three-phase AC circuit, the respective phase relationships are 4 ql ・Qa =, Qa6 3 * Q1 = ql
e-'3'', which becomes lO-.Similarly, the above subtraction is performed for the 22 points and the Ps point to find the potential V2+v3 of the sPR point IP, and then V2 = 2(11(fl, 275 jo, 475 )
Vs = Ks qt ((1,559jO,475).

Next, when calculating the potential difference between each point, the potential difference VlK between 21 and 22 is VI2=V1 v.

=Kzql (0,711-j O,281)-2q
t (-(1,275-j(1,475)=Kz ql
(0,986+j O,194)lVnl=Kz q
l Xl, 005 The potential difference via between P2 and P3 is
(0,599+jO,475)”K2 ql (0,3
24-j O, 95) lVza I= K, ql X
The potential difference V81 between P3 and P1 is VBl ''' V 3 V 1 = Kz qt (0,599+jO,475)-2
qt (0,711 [1281)”'Ka ql (1
,31+j0.756)lV+B l =2q+X
l, 512. The potential at each point and the potential difference ratio vector obtained in this manner are shown in FIG. In actual measurements, the predistribution current pull J7Kldl'Vt
1l, 1vasl, IVIIIK proportional Lt current flows. Table 1 shows the calculated current ratio in a 66 kV disconnector and the actual measured value within 0, and the calculated value and the measured value almost match. Therefore, it can be put to practical use.

Table 1 Phase check side of 66 kV disconnector There was no difference in measurement results depending on the weather conditions, and there was no change when comparing the charging line and load line.

According to the above embodiment, the detector J1. provided on the holding rod 13.14. Phase detection can be performed using only J2 and ammeter 17. Therefore, the device configuration is simple and handling is convenient.

In addition, since it is a primary phase detection, there is no need for a temporarily installed single transformer or related system operations, and phase detection can be performed reliably and in a short time. Moreover, since the manufacturing cost of the phase detector is low, construction costs can be significantly reduced by 13-1 compared to conventional phase detection methods.

In addition, since the height of the detectors JJ and 12 is only about the height of the stand, it is possible to work safely without directly touching the live parts. However, the present invention is not limited to this, and may be implemented as a circular shape or a disc shape, for example. Other modifications may of course be made within the scope of the gist of the present invention.

As mentioned above, according to the present invention, phase detection can be performed reliably in a shorter time than conventional methods, construction costs can be reduced, and special high-voltage detection can be performed safely without directly contacting live parts. We can provide companion equipment.

[Brief explanation of drawings]

Fig. 1 is a configuration diagram showing an embodiment of the special high voltage phase detector according to the present invention, Fig. 2 is a front view showing the detector shown in Fig. 1 taken out, and Fig. 3 is an example of an actual measurement state. Figure 4 is a top view showing the track switch in Figure 3, M
Figures 5 to 14-8 are diagrams shown to explain the 61 fixed principle of this generation, respectively.
7...ni flow meter. Applicant's agent Patent attorney Name Takehiko E 5- Figure 1 Figure 2

Claims (1)

[Claims] A detector is provided at the tip of the insulating rod and is formed of a conductive strip, and two of these detectors are provided at a predetermined distance from the main circuit of the power system and are detected by the detector. A special high voltage phase detector 0 characterized in that it is equipped with an ammeter that measures the current generated by the phase difference between the electrostatic induced voltages of each phase.