JPS5937839A - Ac current limiting device k./juuu,protecting device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention is designed to reduce the extreme fault current limit l+ :F-AC current limiting BIi'? (hereinafter referred to as current limiting device).

One way to suppress the 11φ overflow in a general 52 power system is to connect two current limiting reactors in series (:
There are no means for inserting it. However, the Koya method requires sufficient impedance to sufficiently suppress the fault current of the faulty axis of the system, and since the 1fc current limiting reactor is always inserted into the 8th line, the impedance of ( The drawback was that the voltage drop caused by the transmission was large (which was contrary to the principle of complete power transmission).

In order to eliminate the above drawbacks (: Risa 1 + fc
In this case, a voltage booster or an autotransformer is connected in series with the system line (:
Installation, said transformer,! ′ft is the content, resistance, and input @candy connected in series (=inserted) on the 2nd side of the autotransformer to form the secondary side in an open state during steady state, and the number of systems is 1fl1Pj (
2. Activate the input signal f'I6 connected in series with the above contents and the resistor J: By constructing the transformer 1fc, the secondary side of the autotransformer is formed in a closed circuit, and the iron LrK of a transformer or autotransformer is designed to cause a resonance phenomenon.
In order to suppress the 1g1i overcurrent by rapidly increasing the impedance seen from the side, it is necessary to
11! The impedance seen from i is made sufficiently small, and when a fault occurs in system C2, the impedance increases rapidly at 6:00 pm to suppress the faulty overcurrent IM. purpose.

Now, let's take an example of the present invention and explain 1.
Do J.

1 1 Figure 5 2 1 is above the current limit 1? 1 is 2 divine system S
1° S2 interconnection point a + b (- connection is n. A resistor C and a charging device S are connected to each other.Here, each input device S is, for example, a Gikitsubu steel gate, or a high-speed switch, or a zinc oxide lightning arrester, etc. The nonlinearity of
Then it means 1 device etc. In addition, the air circuit of the transformer T's I-1 (the air circuit is shown in Fig. 2) is inserted with a gap or a non-conducting body to distribute fCg 1 + g 21 g 3 + g %. .

The operation of the present invention having such a configuration will be explained below.

Figure 1 C: First, both systems S □ 1 and S2 are in a healthy state (2 Suke C 2 is Megu Ryuhei N1's feeding device S is in an open state, or a high impedance payment state ≦ 2 Yes, υ [also transformer T's 2 pin 0111 t or 4 Li air (2 is open circuit and is the same as a general glue handle. At this time, current limiting device 1
Since the impedance of is 12 tl (= designed), ifk Jji + loss is connected between both systems S1 and 82 (: becomes 1, now the above state (2), both systems MS If a fault such as a line short circuit occurs in the system of , and S2, an excessive amount of electrical wire will flow into the primary winding N1 of transformer T, but the secondary The voltage across the winding N20 rises rapidly by 1 to the induced electromotive force, so when the induced electromotive force reaches a preset voltage (=, the voltage at both ends of the winding N20 is activated, the 2nd voltage of the transformer T is Next winding N20 Pi5
Content C ↓ and resistor R old issue &: Connect closing P
form 8. Note that if the closing device S is a gap, it will discharge, and if the nonlinear resistance element is a low impedance (=, high-speed switch, semiconductor switch, etc.), it will be closed. induces a state of iron resonance, and the impedance seen from the primary elevation I of the transformer T rapidly increases.

Therefore, the filtration current flowing between the connecting points a and b of the system is limited.

Next 4 = The above phenomenon will be explained using a theoretical formula. 1, that is, the resistance and leakage in the primary and secondary windings of the transformer T60
Neglecting the leakage inductance due to the bundle.

If we consider the magnetic resistance of the iron core of the 1fcK pressurizer T to be linear.

Steady PPJ of this rib (= primary winding N1 of transformer T
The apparent impedance seen from is expressed as a multiple number.

mag According to 1.

However, zab: impedance in a transient state (steady state with respect to two pairs), ω: angular circumference rfR number of the line power supply, n: number of turns of the 1st winding N0 of the transformer T, r mag: magnetism of the iron JL7 of the transformer T The resistance is the impedance length of either line of system S1 or S2 (in the steady state when a fault occurs and the closing device nS is activated).
a b is... (21 However, r is the resistance of the resistor R, n2 is the number of turns of the 2Q winding N2F, and C is the capacitance of the condenser C.

By the way, the magnetic resistance r of the iron core circuit in transformer T
When the following conditions are satisfied between mag, the number of turns n of the secondary winding N20, and the capacitance C of the content C, that is, the iron resonance frequency 12
When forming 1, the above (2; expressed by the formula 117'(
It becomes a. Therefore, from equation (1) and (from equation 41, the number of turns n2 of the two-way winding N2, the resistance r of the resistor R, and the capacitor 111c
Each amount of magnetic resistance r mag of C1 core magnetic circuit gJ
It's easy to find a suitable mag. That is, the n2, r + C
1? It is possible to change the impedance area of X' and C2 to a sufficiently large value.

ζ Trowel, the necessity of resistance R is (4
Type 1 Eri, flaw straightness b becomes infinite, and Ia flow effectiveness appears to increase. However, since the attenuation period 114 of the blood flow component of the current-limiting transient current becomes extremely long and no longer serves as a current-limiting function, appropriate practice is required.

In Figure 3, the power supply voltage is 6.6 kV (maximum volume per frequency is 60)], and the current flowing through the steady ribs is 100 A.
C maximum area), short circuit current is 3.3 k A C foot normal Q,
The current limiting characteristics of the fault overcurrent when the current limiting device N according to the present invention C2 (the closing device S is a gap type) is installed in the distribution system line (Jυ thick f + Q) of 1 is electronically calculated. Eri simulation and fc characteristic prisoner, this 3rd ward =
3 is the drum shape of the gap voltage, 4 is the waveform of steady current 1 outgoing current, 5 is the point of failure, 6 is the waveform of the fault current when a first-class device is inserted, and 7 is the waveform of the fault current when a first-class device is inserted. The waveform of the current limiting current in the case of
1 is the waveform of the current flowing through the capacitor C.

FIG. 4 shows an example of a current limiting device using a single-volume pressure device.1. As is well known, in this example, the insulation of the 1st winding and the secondary winding is the same and the tl is not the same. This has the effect of significantly reducing the cost of the equipment, such as saving on the amount of electricity and reducing the amount of bolting due to the shortening of the magnetic path.

As described above, according to the present invention, the steady IPl (m is 1
In order to minimize the impedance seen from the next side (:
By keeping the two sides of the current limiter in an open state and connecting the system (fcl) i, 217 (Fltl gm m continued), the condenser, and the resistor to the old version to cause fero-resonance. Since the impedance seen from the primary side is rapidly increased to limit the failure overcurrent, there is a possibility that it will be possible to easily and reliably implement thread RAM protection.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of an AC current limiting load showing an embodiment of the present invention, and FIG. 2 is a sectional view showing the M plane of the transformer shown in FIG. 1.
FIG. 3 is a characteristic diagram for explaining the present invention, and FIG. 4 is a circuit P2S configuration diagram showing another embodiment. 1...limit #f Mukuro f1ri, S...inserted! 1i, R...
・Resistance, C...condenser. Note that the same reference numerals in the figures indicate the same or equivalent parts.

Claims (1)

[Claims] The transformer 1fc is interposed between two different types of systems, and the secondary 111 of the transformer or autotransformer is
The transformer 1 is connected in series with n * 1 contents, a resistor and a closing device, and the transformer 1 is connected to two autotransformers.
Connected to the next side t + fc resistor, content, keep the iM column circuit of the input bowl j light in the open state, and if a failure occurs in the system, ft-F#? J(: is the above content, the current limiter whose characteristic is to operate the arrogance as if closing the resistance in a row and causing iron resonance.