JP3044832B2 - Trip circuit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a trip circuit such as a circuit breaker in a protection relay device.

[0002]

2. Description of the Related Art FIG. 2 shows an example of a trip circuit such as a circuit breaker. That is, FIG.
₀ trip circuit relay X ₀ during closing of the operating conditions switch of the relay of (not shown) (contact) Y outputs a trip signal to operate. FIG. 4B shows a trip signal output by operating the trip circuit relays X ₁ and X ₂ when the operating condition Y is closed, and FIG. 4C shows a stationary photocoupler PC ₁ , PC ₂ is operated to output a trip signal via an AND circuit.

[0003] Generally, Y is a relay X ₀ , X ₁ , X ₂ or P
Under operating conditions provided in a device different from C ₁ and PC ₂ , for example, in a high-voltage, extra-high-voltage substation, the bus protection relay Y ₀
Operating conditions. That is, when the bus protection relay Y ₀ is operated, pass the operating conditions such as line protection relay, it is performed to cut off the breaker of the line. In this case, as shown in the case of outputting a trip signal is received by one of the auxiliary relay (trip circuit relay) X ₀ as shown in FIG. 2 (a), the same figure (b), (c) In order to improve the reliability, a trip signal may be output under the AND condition of X ₁ , X ₂ or PC ₁ , PC ₂ . Note that P,
N is a positive terminal and a negative terminal of the DC power supply.

[0004]

Amplification of contacts as shown in FIG. 2 (more contacts that perform the same operation with one contact)
When adding a Y operation condition to a circuit that creates trip conditions such as a circuit breaker (hereinafter collectively referred to as a trip circuit), if the cable is wired with a dotted line from a separate device and the distance is long In this case, the ground capacities C ₁ and C ₂ (see FIG. 3) can be as large as 1 km, as will be described later. On the other hand, in the control of high-voltage and extra-high-voltage substations and power plants, in addition to the DC circuit, an AC circuit is also included. Interaction may occur. When they come into contact with each other, the battery as the DC power supply E becomes a large-capacity capacitor in terms of AC and has almost no impedance. For this reason, in the case of FIG. 3A, when the contacted AC is in a positive half cycle at the terminal P side, the batteries E,
Relay X _2, current flows through the earth capacitance C _2, relay X
₂ is operated, since the time of the next half cycle operates X ₁ at the same time, operating conditions Y relay X ₁ is also not operated, X ₂ is operated to trip signals of both the relay and conditions are satisfied the output I do. In the case of AC touch in the stationary type shown in FIG. 2B, when the AC is 50 Hz, PC ₁ operates in 10 ms and PC ₂ operates in the next 10 ms. Here, since the photocouplers PC ₁ and PC ₂ have a slight recovery time,
When operating alternately, there is a risk that the other will operate and output a trip signal before one returns. Although the description is omitted, a malfunction occurs in the case of FIG.

[0005]

According to the present invention, a switch that operates when the operating condition is satisfied and a relay for a trip circuit are connected in series to both terminals of a DC power supply, and when the switch operates,
The trip circuit relay operates to output a trip signal.
In the trip circuit, the trip circuit
Series resonance of reactor and capacitor in parallel with
Circuit, and the series resonance circuit
AC current that has low impedance with respect to
Circuit. Also, circuit relays
Connect a parallel resonant circuit of a reactor and a capacitor in series
And, the parallel resonance circuit has a
High impedance prevents interfering alternating current and direct current
The part is a circuit flowing through the reactor. Also, birds
In order to improve the reliability of the
Operates between relay and negative terminals when relay operating conditions are satisfied
The trip circuit relay connected in series with the switch
At least two are provided, and the trip signal is
Output.

[0006]

[Function] A series resonance circuit in parallel with a trip circuit relay
The provision of, if AC is incompatible to the DC power supply circuit, the resonance circuit resonates with the frequency of the alternating current, low impedance
Bypass the current flowing through the trip circuit for the relay become a
To prevent the trip circuit relay from malfunctioning. Again
When a parallel resonance circuit is provided in series with the lip circuit relay
Has a high impedance with respect to the frequency of the
To prevent the contacted AC,
Prevent malfunction. At this time, the DC component from the DC power supply is
Normal operation because it flows on the reactor side of the parallel resonance circuit
Does not cause any trouble. Trip circuit connected in series
At least two relays for
By outputting a trip signal, reliability is improved.
Is improved.

[0007]

FIG. 1 shows an embodiment of the present invention. The same parts as those in FIGS. 2 and 3 are denoted by the same reference numerals and the description thereof will be omitted. That is, in the present invention, in FIG. 1A, the resonance circuits 1 and 11 are connected in parallel with the relays X ₁ and X ₂ , respectively. Each of the resonance circuits 1 and 11 is formed of a series circuit of a reactor L and a capacitor C, and is a series resonance circuit that resonates at a contacting AC frequency. FIG.
FIG. 1 (b) shows each of the photocouplers PC ₁ and PC ₂ in parallel with FIG.
In this example, the same resonance circuits 1 and 11 as in FIG.

The operation of the present invention configured as described above will be described.

In FIG. 1A, when a normal operation condition is satisfied and a condition signal Y is input, a current flows from a DC power supply terminal P to a terminal N through a relay X ₁ , a contact Y, and a relay X _2. The relays X ₁ and X ₂ are each energized, and a trip signal is output when each of the contacts is closed. In such a trip circuit, if an alternating current touches the terminal P, the resonance circuits 1, 11
Resonate and the impedance decreases. Therefore, when the terminal P has a positive half cycle, current flows to the resonance circuit 1 and the ground capacitance C ₁ , and when the terminal N has a positive half cycle, the current flows to the resonance circuit 11 and the ground capacitance C ₂ . , The sensitivity of the relays X ₁ and X ₂ is greatly reduced and no malfunction occurs.

1B, the current flowing in each photocoupler is diverted to the resonance circuits 1 and 11, so that malfunction due to AC cross-contact can be prevented. In addition, in each embodiment,
Although a series resonance circuit is connected in parallel with the relay for preventing malfunction, the relays X ₁ and X ₂ and the photocoupler PC are connected.
_1, connected to the PC ₂ the parallel resonant circuit connected in parallel a reactor and a capacitor in series, high for AC was mixed contact
Impedes the AC and blocks direct current from the DC power supply.
The same effect can be obtained by passing the flow through the reactor side.
Of course, it can be done.

[0011]

As described above, according to the present invention, even if an AC control power supply comes into contact with a DC circuit, a trip circuit or the like does not operate erroneously. In the case where the operating conditions of other devices are transferred via a cable, there has been a certain restriction at the same time as paying attention to the ground capacitance of the transfer cable, but according to the present invention, There are no restrictions.

[Brief description of the drawings]

FIGS. 1A and 1B are configuration diagrams showing one embodiment of the present invention, in which FIG. 1A shows a case where an auxiliary relay is used, and FIG. 1B shows a case where a photocoupler is used.

FIG. 2 shows an example of a conventional trip circuit.
Is the case where one auxiliary relay is used, and (b) is the auxiliary relay 2
(C) shows the case where a photocoupler is used.

FIG. 3 is an explanatory diagram of a case where an AC touch occurs with a DC circuit;
(A) shows the case where an auxiliary relay is used, and (b) shows the case where a photocoupler is used.

[Explanation of symbols]

1, 11 ... resonant circuit X _1, X ₂ ... trip circuit for the relay PC _1, PC ₂ ... photo-coupler Y ... conditions are met for the switch

Claims (3)

(57) [Claims] Between 1. A positive electrode of the DC power supply and the negative of the terminals to connect the switch and the trip circuit relay that operates when satisfied operating conditions of the relay in series, the dynamic of the switch
During trip operation, the trip circuit relay operates to output the trip signal.
In a trip circuit designed to output
In parallel with the relay for the
A column resonance circuit is connected, and the series resonance circuit
Contact with low frequency impedance
A trip circuit characterized by a flow circuit. To 2. A positive electrode of the DC power source and between the negative electrode of the terminals, switches and birds that operate during establishment operating conditions of the relay
Connected in series with the
During trip operation, the trip circuit relay operates to output the trip signal.
In a trip circuit designed to output
And a capacitor and a capacitor in series with the
A column resonance circuit is connected, and the parallel resonance circuit
Contact with high frequency impedance
Block the flow, and the DC component is
A trip circuit characterized by: 3. Between the positive and negative terminals of a DC power supply.
And a switch that operates when the relay operating conditions are satisfied.
Connect at least two trip circuit relays.
Output a trip signal under the AND condition.
The trip circuit according to claim 1 or 2, wherein: