JPS631394Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-speed operation, large-capacity auxiliary relay circuit used when issuing a closing command to a breaker.

A characteristic of electromagnetic auxiliary relays is that high-speed operation auxiliary relays are required to have a mechanically lightweight contact structure because the purpose is high speed. On the other hand, when connecting a breaker closing coil (inductive load) with a current of several amperes flowing through a 100V DC control power supply, a current of several amperes also flows to the closing command contact connected in series with this coil. The auxiliary relay is equipped with a magnetic blow-off device to quickly cut off the current when the closing command contact returns, and the contact structure is also larger.
Therefore, low-speed operation is inevitably unavoidable. Figure 1: System diagram of Nishiya breaker closing circuit
Give an example. The CB bridge, disconnector, and EQ are automatic synchronization devices. The automatic synchronization closing device EQ determines the closing conditions for the circuit breaker CB using the voltage introduced from each potential transformer PT-B and PT-L. For this reason,
Automatic synchronization devices require high speed operation.
Figure 2 shows the bus line BUS and transmission line LINE in Figure 1.
An example of the phase relationship between In the phase plane of the power system voltage shown in Figure 2, when the circuit breaker CB is turned on,
There is a risk that the breaker cannot be closed within the required phase difference of 0° to ±θ° and may be closed at a point outside of this range. Automatic synchronization device EQ uses bus line BUC voltage〓E
₁ and transmission line LIN〓E voltage〓E ₂ After confirming mutual synchronization,
It is necessary to turn on the breaker when the allowable phase difference is between -θ and O+θ. Figure 3 shows bus line BUS and power transmission line LIN
〓 Shows the moving state of the phase plane of E. In Figure 3,
If the bus line BUS _voltage〓E1 is taken as a reference and the transmission line LIN〓E _voltage〓E2 is used as the dependent (comparison) side, if there is a slight frequency difference between the two, each voltage will change as shown in Figure 3. The vector rotates on the phase plane, and even if the closing condition is satisfied near the phase difference +θ and a closing command is given to the switch, the voltage vector will rotate (move) and the switch will not actually disconnect. If a low-speed operation relay is used to connect the primary circuit of the power supply, the actual power-on phase difference will be θ+θ', and the shock given to the power system will be large. To avoid this, there is a method of assuming a phase shift of θ' in advance and narrowing the phase difference θ. This method narrows the input range, which is not preferable in terms of power system operation.

Recently, automatic control of insulators and disconnectors has been carried out using electronic computers, but such a case still requires high-speed relays as described above. As described above, there are many similar cases, and there is a great need for high-speed, large-capacity relays. FIG. 4 shows a conventional contact amplifier circuit. In Fig. 4, F indicates the closing command contact, X indicates its signal amplification contact, and the closing coil of the CB armature or disconnector. For example, if the contact point for the line breaker closing command is F, then the auxiliary relay X, which has a large current line breaker capacity, issues a closing command to the line breaker CB.
In this case, it is generally difficult to increase the operating speed of the auxiliary relay X due to its contact structure.

The object of the present invention is to obtain a closing command circuit for a shunt breaker that has a high operating speed and a large capacity contactor. FIG. 5 shows an example of the present invention. In Figure 5, F is the closing command point, Y is the high-speed moving auxiliary relay, Y _-a1 and Y _-a2 are the output contacts of the auxiliary relay, and Z
indicates an auxiliary relay with a large current flow and disconnection capacity, Z _-a indicates the output contact of the same auxiliary relay, CB terminal and breaker closing coil, and P and N indicate the DC control power supply. According to this, the first input signal to the breaker CB is
This is done at contact Y _-a1 of auxiliary relay Y, and then auxiliary relay Z bypasses the contact of auxiliary relay Y to protect it. When the closing command F returns, the auxiliary relay Y returns first, and then the auxiliary relay Z returns. By doing so, the control current of the breaker CB is cut off by the auxiliary relay Z, and a high-speed operation large-capacity contact auxiliary relay circuit can be obtained.

FIG. 6 shows a time diagram of this circuit. In FIG. 6, F is a closing command contact, Y is a high-speed operation auxiliary relay, Z is an auxiliary relay with a large current breaker capacity, and I is a breaker closing current.
As shown in Fig. 6, the line breaker closing command is delayed by the operation time delay _t1 of the high-speed operation auxiliary relay Y, and when the auxiliary relay Z, which has a large current line breaker capacity, is used. The time can be reduced by _t2 .

_t3 is the recovery time of the auxiliary relay, which has a large current and breaking capacity.

[Brief explanation of the drawing]

Figure 1 is a block system diagram of the breaker closing circuit, Figures 2 and 3 are phase characteristic diagrams of the power system and synchronous closing device, Figure 4 is a conventional auxiliary relay circuit diagram, and Figure 5 is a diagram of the conventional auxiliary relay circuit. The figure is a circuit diagram of the invention, and FIG. 6 is a time diagram of the invention circuit. P and N are power bus bars, Y is a high-speed operation type auxiliary relay, F is a command signal contact, CB is a breaker control coil, and Z is an auxiliary relay with a large current breaker capacity.

Claims (1)

[Scope of utility model registration request] a fast-acting first auxiliary relay that is energized by the closing of the closing command contact; a breaker closing coil that is energized when the first output contact of the first auxiliary relay is closed; 2nd of 1st auxiliary relay
is energized when the output contact of the first auxiliary relay is closed, and has a larger current carrying capacity than the first auxiliary relay, and
and a second auxiliary relay with a long recovery time, and the output contact of the second auxiliary relay is connected in parallel to the first output contact of the first auxiliary relay to issue a command to close the circuit breaker. circuit.