JPS6127984B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a distribution line transport control system that performs two-state control using a distribution line as a transmission path.

A power distribution automation system is generally configured as shown in FIG. In the figure, 1 is a substation, 2 is a master station, 3 is a high voltage coupler, 4 is a loop point accident investigation device, 5 is a high voltage distribution line, 6 is an accident investigation device for selective sequential transmission, and 7 is a loop point. . Loop point 7 is a normally open contact placed at a suitable location in the distribution line network, and can be switched into two states, locked and unlocked, under control from the master station.
take a state. The unlocked state is a state in which loop point 7 can automatically switch to disconnect the faulty section and supply power to the healthy section in order to ensure uninterrupted power in the healthy section in response to an accident on the power distribution line. be. On the other hand, a locked state is a state in which the automatic switching function of loop point 7 is temporarily stopped because if accidents occur frequently on the distribution line, there is a risk that the accident will spread if the loop point 7 has an automatic switching function. Point.

In FIG. 1, when the loop point 7 is in the unlocked state under the control of the master station 2, when the accident investigation device 6 for selective sequential transmission disconnects the accident section, the loop point accident investigation device 4 operates and the loop point 7 will be introduced to ensure uninterrupted power outages in healthy sections. On the other hand, when a lock control signal is injected from the master station 2 to the high voltage distribution line 5 through the high voltage coupler 3, the loop point fault investigation device 4 locks the loop point 7 and prohibits the input.

Regarding the above-mentioned two-state control, conventionally a control signal as shown in FIG. 2 has been used. FIG. 2A shows the period of two states to be controlled by the master station 2, and _FIG.
and unlock control signal _B2 . When the loop point accident investigation device 4 receives one of these two control signals B ₁ and B ₂ , it holds the loop point in one state until the other control signal arrives.

However, when using a distribution line as a transmission path, the amount of signal attenuation between the master station 2 and the loop point accident investigation device 4 is the same as the amount of signal attenuation between the master station of another system and the loop point accident investigation device (crosstalk). As a result, when a lock release control signal _C1 is generated from another system as shown in FIG. 2C, loop point 7
As shown in FIG. 2D, the state is different from that in FIG. 2A, and the loop point 7 is erroneously turned on during a period when it should be in the locked state, as shown in FIG. 2E.

In such two-state control, a malfunction may occur during the lock release period when the loop point 7 wraps around and becomes locked, but in this case, even if the power outage rate in the healthy section increases, the expansion of the accident can be prevented. However, as shown in FIG. 2, a malfunction that causes the lock to be released during the lock period should be avoided as much as possible because it will lead to an accident.

The present invention has been made in view of the above points, and in two-state control using power distribution lines as transmission paths,
To provide a distribution line transport control system that prioritizes two states and prevents transition from a priority state to a non-priority state due to malfunction.

Hereinafter, an embodiment of the present invention will be described with reference to FIGS. 3 to 5, in which the lock state is prioritized during two-state control of loop points in a power distribution automation system. FIG. 3 is a configuration diagram of the power distribution automation system, and the same parts as in FIG. 1 are given the same reference numerals. The master station 2 shown in the figure includes a control signal generation circuit 21 that generates a lock control signal and an unlock control signal, and an AM control signal generation circuit 21 that amplitude modulates a carrier wave with the output of the control signal generation circuit 21.
A modulation circuit 22 and an amplifier circuit 2 that amplifies this output.
3. In addition, loop point accident investigation device 4
, two systems of AM demodulation circuits 41 _a and 41 _b , and a control signal discrimination circuit 42 that detects and discriminates a lock control signal and an unlock control signal from their outputs.
_a , _42b , and an OR circuit 43 that controls the state of the loop point 7 by the OR of these determination results.

In the above configuration, the master station 2 connects the loop point 7 to the fourth
When control is performed as shown in FIG. 4A, the control signal generating circuit 21 generates the lock control signal B ₃ and the lock release control signal B ₄ as shown in FIG. 4B according to the divisions shown in FIG. 4A. The lock control signal _B3 consists of a pulse train that repeats at short intervals over the entire lock period, and each pulse has a meaning as a lock control signal. The period of this pulse train is determined from when the loop point accident investigation device 4 receives the lock release control signal to when the loop point 7
The protection time until the power is turned on is set to be shorter than the protection time X. On the other hand, the unlock control signal _B4 is sent out only for a short period of time at the time of state switching.

If the control signal has such a form, when the master station 2 is transmitting the lock control signal _B3 shown in FIG. 4B, the lock release control signal of another system shown in FIG.
Even if C ₃ is received by the loop point accident investigation device 4 and the loop point 7 attempts to become unlocked by mistake,
Since the lock control signal _B3 is received again within the protection time X, the lock will not be erroneously unlocked during the lock period, and the spread of the accident can be prevented.

In this case as well, there is a malfunction in which the loop point 7 becomes locked during the lock release period due to a part of the lock control signal _C2 of the other system, but this is allowed for the same reason as mentioned above. In the end, due to the original control signal B and the looped control signal C, the state of loop point 7 becomes as shown in Fig. 4D, but the input of loop point 7 is due to the original lock release as shown in Fig. 4E. The safety of the distribution automation system is improved because it is carried out only during the period.

In the embodiment, the lock release control signal _B4 is
As shown in the figure, it is sent only at the time of state switching. Therefore, if noise similar to the lock control signal _B3 is mixed into the lock release period which generally lasts a long time, the lock state will be unnecessarily caused.
Although the above embodiment deals with malfunctions due to wraparound, unnecessary locking due to malfunctions due to noise is undesirable in that, even if safety is ensured, the automatic switching function of the power distribution automation system will be inhibited. In such a case, as shown in FIG. 5B, if the lock release control signal _B4 is repeatedly sent out not only at the time of state switching, but also when the lock release control signal B4 is repeatedly sent out, noise N that is similar to the lock control signal _B3 will be mixed in and the loop point will be lost. Even if the state of loop point 7 once becomes the locked state as shown in FIG. 5C, the loop point 7 can be restored to the unlocked state again by the next unlocking control signal _B4 . During the lock release period shown in FIG. 5A, the lock release control signal _B4 is repeatedly sent at a cycle longer than the protection time X described above.

In the embodiment, the lock control signal and the unlock control signal are distinguished by time width, but they may also be distinguished by having different frequencies. The lock control signal may be sent out continuously during the lock period, especially if the frequencies are different.

As mentioned above, when performing two-state control using a power distribution line as a transmission path, priority is assigned between the two states,
The distribution line transport control method of the present invention, in which the control signal for the priority state is transmitted continuously or repeatedly in short cycles during the control period, and the control signal for the non-priority state is transmitted repeatedly only for a short period of time or in long cycles when switching states. If so, even if there is a signal wrap-around phenomenon unique to high-voltage distribution lines, it is possible to prevent malfunctions in which a priority state shifts to a non-priority state due to control signals from other systems.

It is clear that the priority state and non-priority state are not limited to the locked state and unlocked state of the loop point, but may be two states of other controlled objects.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an example of a power distribution automation system, Fig. 2 is a time chart for explaining conventional loop point two-state control, Fig. 3 is a block diagram showing an embodiment of the present invention, and Fig. 4 is a block diagram showing an example of a power distribution automation system. 5 and 5 are different time charts used to explain the same embodiment. 1... Substation, 2... Master station, 3... High voltage coupler, 4... Loop point accident investigation device, 5... High voltage distribution line, 6... Accident investigation device for selective sequential transmission, 7... Loop Point, 21... Control signal generation circuit, 22... AM modulation circuit, 23... Amplification circuit, 41 _a , 41 _b ...
AM demodulator, 42 _a , 42 _b . . . control signal discrimination circuit, 43 . . . OR circuit.

Claims (1)

[Claims] 1 In a distribution line transfer control method in which a control side sends a control signal to a controlled object using a distribution line as a transmission path, and thereby sets the controlled object in two predetermined states, a priority is set between the two states. and a second state in which the controlled object corresponds to a non-priority state.
When setting a controlled object to a priority state by providing a predetermined protection time between receiving the first control signal and shifting to a non-priority state, the first control signal corresponding to the priority state is set to the priority state. If the controlled object is transmitted continuously during the period when the controlled object is set to the priority state or repeatedly at a cycle shorter than the protection time of the controlled object, and is set to the non-priority state, the second control signal is transmitted at the time of switching. A power distribution line transport control system characterized in that the transmission is repeatedly transmitted for a short period of time or at a cycle longer than the protection time of a non-controlled object.