WO2021244242A1 - Transient voltage locking module for power distribution terminal - Google Patents

Abstract

Disclosed is a transient voltage locking module for a power distribution terminal, comprising a power module, a voltage acquisition and comparison module, and a transient voltage state latch module electrically connected to each other. The power module is an AC/DC module used for converting a 220 V alternating current converted from a line PT into a 5 V direct current and supplying same to a post-stage circuit for use. The voltage acquisition and comparison module is used for detecting the voltage of the load side and the voltage of the power supply side of a switch at any time, comparing the voltages with a set first threshold, determining whether an instantaneous voltage exists or not, comparing the instantaneous voltage with a set second threshold and determining whether a normal power supply state exists or not. The transient voltage state latch module comprises a passive contact used for realizing short circuit or disconnection according to the comparison result of the voltage acquisition and comparison module and keeping an on-off state after power loss. In this way, the transient voltage locking module for the power distribution terminal can keep the transient voltage state on the line after the line loses power, and information is provided for the power distribution terminal.

Description

Transient voltage blocking module for power distribution terminal Technical field

The invention relates to the field of power distribution automation, in particular to a transient voltage blocking module for a power distribution terminal.

Background technique

Modern power supply and distribution are working hard to improve the level of automation and improve the stability of power supply and distribution. One of the most important links is to realize automatic isolation of faulty lines.

If there is a fault on the line, after the upper switch is closed, the upper switch will trip immediately due to the fault on the line. At this time, the switch on this line will detect the voltage that exists and disappears instantaneously. According to industry standards, if If voltage information of >30% of the rated voltage is detected on the line, but the duration is >80ms and <3 seconds, it is judged that there is an instantaneous voltage on the line, referred to as transient voltage. This transient voltage state on the distribution line can characterize the line fault. Now the switch on the line detects the instantaneous voltage situation and automatically shuts down or closes in combination with the set waiting time, that is, if the switch on the line detects the instantaneous voltage If the voltage exists, it will be automatically locked and automatic closing is prohibited, so as to realize the isolation of the fault line after the switch. When the upper switch automatically closes again, the power supply to the user before the switch can be restored, thereby realizing the failure Automatic isolation of lines and quick restoration of power supply to non-faulty lines.

This function of opening and closing the lock after detecting the instantaneous voltage is called "transient voltage lockout".

Each switch itself only has the function of opening and closing. The transient voltage blocking function requires the main controller in the power distribution terminal to detect and judge the transient voltage, and then the main controller controls the relevant mechanism to realize the blocking function of the switch. In order to detect and judge the transient voltage, the power distribution terminal itself needs to be in a power supply working state. Moreover, the instantaneous voltage is on the premise that there is a fault on the line, try to transmit power to the line, and activate the protection action of the upper switch. If the distribution terminal has been in the normal power supply state since the moment the instantaneous voltage was detected last The power distribution terminal can maintain the lockout function of the corresponding switch of the faulty line, but if the intermediate power distribution terminal loses power and the power of the backup power supply inside the power distribution terminal is also exhausted, it will be lost when the power distribution terminal is running again. For the memory of the previous instantaneous voltage, the state of the subsequent circuit is in an unknown state. In the case of unknown line fault status at the distribution terminal, closing the control switch will cause the switch to be closed on the faulty line, causing the outlet circuit breaker to trip, resulting in a power outage, and damaging the power supply of many normal lines.

If the transient voltage information detected last time can be recorded, and after the power distribution terminal restarts, the transient voltage information will be transmitted to the power distribution terminal, the power distribution terminal can "restore memory" and realize the lockout of the corresponding switch of the faulty line , To avoid closing to the fault.

Summary of the invention

The technical problem to be solved by the present invention is to provide a transient voltage blocking module, which can keep and record the transient voltage state that has occurred on the line for use by the power distribution terminal.

In order to solve the above technical problems, the technical solution adopted by the present invention is:

A transient voltage blocking module for a power distribution terminal includes a power supply module, a voltage acquisition and comparison module, and a transient voltage state latch module that are electrically connected to each other.

The power supply module is an AC/DC module, and the AC/DC module is used to convert 220V alternating current converted from the line PT (voltage transformer) into 5V direct current for use in the subsequent circuit.

The voltage acquisition and comparison module detects the voltage on the load side and the power side of the switch at all times, and compares it with the set first threshold to determine whether there is an instantaneous voltage; at the same time, it compares with the set second threshold to determine whether it is normal Power supply status.

The transient voltage state latch module includes a passive contact, and the passive contact realizes short-circuiting or disconnection according to the comparison result of the voltage acquisition and comparison module, and maintains the on-off state after power loss. The passive contact is sent to the inside of the power distribution terminal as a remote signal state.

Compared with the prior art, the present invention has the following technical effects:

After the power distribution terminal is equipped with a transient voltage blocking module, there is no need to provide power to this module, just connect the 220V AC power of the power distribution line to the module in parallel. This design can reduce the amount of modification that users add to the module, and it will not increase the distribution. The internal power consumption of the electric terminal; the output of the passive contact of the module can meet the active or passive remote signal interface of different users, with high versatility.

The line is out of power and the backup power supply of the power distribution terminal is exhausted. When it is put into use again, the power distribution terminal judges whether there is a fault at the back end of the line by reading the on and off of the passive contact in the transient voltage latch module of the transient voltage latch module Therefore, the switch corresponding to the faulty line is blocked to ensure that it will not be closed to the faulty line twice, and the stability of the power supply is improved.

On the basis of the above technical solution, the present invention can also be improved as follows.

Preferably, the power supply module simultaneously obtains power from the PT on the load side and the PT on the power supply side of the switch.

The beneficial effect of adopting the above-mentioned further scheme is that it is suitable for the current ring network power supply mode. Because the instantaneous voltage is mainly in the case of no power on the line, try to supply power, because the fault occurs instantaneous tripping, and the ring network can be powered from both sides. Taking power from one side can ensure that no matter which side has a fault, electric energy can be obtained. As long as the instantaneous voltage on the line lasts for 80ms, the electricity induced from this 80ms instantaneous voltage is sufficient to support the present invention to complete the instantaneous voltage state lock live.

Preferably, the passive contact adopts a self-holding relay.

The beneficial effect of adopting the above-mentioned further scheme is that the existing mature technology products have stable operation and low cost.

Preferably, there are two passive contacts.

The beneficial effect of adopting the above-mentioned further solution is that different contacts can be used to indicate the faults on the user side and the power side respectively, and the description of the faults is more accurate.

Description of the drawings

Figure 1 is a schematic diagram of a power distribution line equipped with the present invention;

2 is a schematic structural diagram of the transient voltage blocking module for power distribution terminal of the present invention;

The names of the parts or functional modules indicated by the numbers in the drawings are as follows:

A. Transient voltage blocking module; PT1, power-side voltage transformer; PT2, load-side voltage transformer;

1. Voltage module; 2. Voltage acquisition and comparison module; 3. Transient voltage state latch module; CK1, left substation exit switch; CK2, right substation exit switch; KG1, load switch 1; KG2, tie switch; KG3, Load switch 3.

detailed description

The principles and features of the present invention will be described below with reference to the accompanying drawings. The examples cited are only used to explain the present invention, and are not used to limit the scope of the present invention.

Please refer to Figure 1 for the distribution line equipped with the transient voltage blocking module of the present invention. CK1 and CK2 are the outlet switches of the left substation and the right substation respectively, and KG1, KG2, and KG3 are the load switches on the line. Configure a power distribution terminal separately; KG2 runs in the contact switch state to avoid simultaneous power supply by the two-sided transformers. PT1 is a voltage transformer located on the power supply side of KG1, used to induct power from the power supply side line and detect power on the line Voltage; PT2 is a voltage transformer located on the load side of KG1, used to induct electricity from the load side line and detect the voltage on the line;

Please refer to Figure 2, a transient voltage blocking module for a power distribution terminal, including a power supply module, a voltage acquisition and comparison module, and a transient voltage state latch module that are electrically connected to each other.

The power supply module 1 is an AC/DC module, which draws power from PT2 on the load side of the switch and PT1 on the power supply side at the same time. The AC/DC module is used to convert the 220V alternating current converted from the line PT into 5V direct current for use by the subsequent circuit. Since this module is used when there is no power in the line, it takes power from the power supply side and the load side respectively, which can ensure that there is a transient voltage phenomenon in any direction. The module can obtain power from the line, thereby latching the transient voltage information.

The voltage acquisition and comparison module 2 detects the voltage on the load side and the power side of the load switch KG1 at all times, and compares it with the set first threshold to determine whether there is an instantaneous voltage. In general, the first threshold is set to the line rated voltage The duration is greater than or equal to 80ms, that is, if there is a voltage greater than 30% of the rated voltage and the duration is greater than 80ms, it is determined that there is an instantaneous voltage on the line. At the same time, it is compared with the set second threshold to determine whether it is a normal power supply state. Generally, the second threshold is set to 80% of the rated voltage for a duration of 4s, that is, if there is more than 80% of the rated voltage on the line and the duration exceeds If the voltage is 4s, it is deemed that the line has resumed normal power supply.

The transient voltage state latch module includes a passive contact, and the passive contact adopts a self-holding relay. The self-holding relay realizes short-circuiting or disconnection according to the comparison result of the voltage acquisition and comparison module, and maintains the on-off state after power loss. The passive contact is sent to the inside of the power distribution terminal as a remote signal state.

When the module detects the transient voltage state, it will latch the transient voltage state and provide it to the power distribution terminal. After the power distribution terminal detects this signal, the corresponding switch KG1 will be blocked, prompting the operation and maintenance personnel to come for repairs, and the operation and maintenance personnel After the maintenance is completed, KG1 needs to be manually closed or unlocked. After closing, if the fault on the line has disappeared, the line will resume normal power supply. After the voltage acquisition and comparison module 2 detects a voltage signal greater than the second threshold, it will be transient The passive contact in the status latch module is released, and the line resumes normal power supply.

The foregoing descriptions are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection of the present invention. Within range.

Claims (4)

1. A transient voltage blocking module for a power distribution terminal, which is characterized by comprising a power supply module, a voltage acquisition and comparison module, and a transient voltage state latch module that are electrically connected to each other;

   The power supply module is an AC/DC module, and the AC/DC module is used to convert the 220V alternating current converted from the line PT into 5V direct current for use by the subsequent circuit;

   The voltage acquisition and comparison module detects the voltage on the load side and the power side of the switch at all times, and compares it with the set first threshold to determine whether there is an instantaneous voltage; at the same time, it compares with the set second threshold to determine whether it is normal Power supply status

   The transient voltage state latch module includes a passive contact, and the passive contact realizes short-circuiting or disconnection according to the comparison result of the voltage acquisition and comparison module, and maintains the on-off state after power loss.
2. The transient voltage blocking module for a power distribution terminal according to claim 1, wherein the power supply module draws power from the PT on the load side and the PT on the power supply side of the switch at the same time.
3. The transient voltage blocking module for a power distribution terminal according to claim 1 or 2, wherein the passive contact adopts a self-holding relay.
4. The transient voltage blocking module for a power distribution terminal according to claim 1 or 2, characterized in that there are two passive contacts.

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