CN218733254U - A network-load coordinated control device for power supply restoration of low-voltage lines - Google Patents

Abstract

The utility model discloses a network-load coordinated control device for low-voltage line power supply recovery, which comprises an analog input module, a switch input module, a switch output module, a logic control module, and a communication module; the analog input module Collect the low-voltage busbar voltage of the single-power incoming line substation and the incoming line current on the low-voltage side of the main transformer; The low-voltage side incoming line switch, the low-voltage tie line switch and the load switch are opened; the logic control module receives the information of the analog input module and the digital input module, executes the power supply restoration logic and the load switching logic, and outputs The module outputs control signals, and the information is uploaded to the substation monitoring system through the communication module. The utility model can effectively solve the power supply recovery problem of the low-voltage line after the voltage loss of the single power substation, and improve the power supply guarantee level of the distribution network.

Description

A network-load coordinated control device for power supply restoration of low-voltage lines

technical field

The utility model belongs to the technical field of electric power automatic control, and in particular relates to a network-load coordination control device for low-voltage line power supply recovery.

Background technique

With my country's economic development and social progress, the electricity consumption of industrial and agricultural production and people's livelihood is increasing year by year, and the requirements for the reliability of power supply in the power sector are also getting higher and higher. In many rural grid areas covered by the State Grid Corporation of China, due to the weak local grid structure, the guarantee of power supply is still a prominent problem. There are still many substations with a single power supply line of 110 kV and below. Once the power supply line fails permanently, it will cause the load loss of the whole station. If the low-voltage side is connected to the energy storage system, it will also lead to the loss of energy storage capacity. It is considered that there is no installation condition for the standby automatic switching device, and it is often necessary to add a new power supply line before considering to increase the reliability of the power supply of the substation by adding the standby automatic switching device. However, limited by conditions such as load level and power grid economic planning, it often takes a long time to add new power supply lines, resulting in the problem of insufficient power supply reliability of single power supply and single main transformer substation that cannot be effectively solved for a long time, and the operation and maintenance unit is faced with huge equipment. Operation and maintenance and power supply service pressure.

Utility model content

In order to solve the above-mentioned technical problems existing in the prior art, the utility model provides a network-load coordinated control device for power supply recovery of low-voltage lines, which is used to improve the reliability of power supply of medium and low-voltage power grids.

The technical scheme that the utility model solves its technical problem adopts is:

A network-load cooperative control device for low-voltage line power supply recovery, including an analog input module, a switch input module, a switch output module, a logic control module, and a communication module; the analog input module is connected to the logic control module; The switching value input module is connected with the main transformer low-voltage side incoming line switch, the control mechanism of the low-voltage tie line switch and the main transformer protection device, and collects the position signals of the low-voltage side incoming line switch and the low-voltage tie line switch, and the main transformer protection action signal; The switching value output module is connected with the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch control mechanism, and controls the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch to open; the logic control module After receiving signals from the analog input module and the digital input module, and executing the power supply recovery logic and load switching logic, the control signal is output through the digital output module, and the information is uploaded to the substation monitoring system through the communication module.

Further, it also includes a low-voltage busbar transformer connected to the analog input module to collect the low-voltage busbar voltage of the single-power incoming substation.

Further, it also includes a current transformer on the low-voltage side of the main transformer, which is connected to the analog input module to collect the incoming current of the low-voltage side of the main transformer in the single-power incoming line substation.

A power supply system using a network-load coordinated control device, including a network-load coordinated control device, a single power supply incoming line substation, a main transformer low-voltage side incoming line switch, a low-voltage tie line switch, multiple power supply incoming line substations, a load switch, and a single power supply incoming line The line substation is connected to the 10kV busbar through the main transformer low-voltage side incoming line switch, the multi-power incoming line substation is connected to the 10kV busbar through the low-voltage tie line switch, one end of the load switch is connected to the load, and the other end is connected to the 10kV busbar. The network-load coordinated control device is respectively connected to the single-power incoming line substation, the main transformer low-voltage side incoming line switch, the low-voltage tie line switch, the multi-power incoming line substation, and the load switch. The network-load coordinated control device collects the low-voltage bus voltage of the high-voltage substation , Multi-power incoming line substation voltage, position signal of main transformer low-voltage side incoming line switch and low-voltage tie line switch, main transformer protection action signal, control the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch.

The beneficial effects of the utility model are as follows: the utility model deploys the network-load cooperative control device in the substation with a single power supply line, and when the upper power grid fails and loses the single power supply or the internal failure of the main transformer causes the substation to lose voltage, the control switches to the low-voltage interconnection line Power supply, and ensure the power supply of important loads according to the load limit. For those connected to the energy storage system, it can not only ensure the grid-connected operation of the energy storage system, but also reduce the amount of load shedding. It can effectively solve the problem of power supply restoration of low-voltage lines after a single-power substation loses voltage, and improve the power supply guarantee level of the distribution network.

Description of drawings

Fig. 1 is the structural representation of the utility model.

Fig. 2 is a schematic diagram of a power supply system using a network-load coordinated control device.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments.

As shown in Figure 1, the utility model includes an analog input module, a switch input module, a switch output module, a logic control module, and a communication module;

The analog quantity input module is connected with the low-voltage busbar transformer and the main transformer low-voltage side current transformer, and collects the low-voltage busbar voltage and the main transformer low-voltage side incoming line current of the substation with single power supply incoming line;

The switching value input module is connected with the main transformer low-voltage side incoming line switch, the control mechanism of the low-voltage tie line switch and the main transformer protection device, and collects the position signals of the low-voltage side incoming line switch and the low-voltage tie line switch, and the main transformer protection action signal;

The switching value output module is connected with the main transformer low-voltage side incoming switch, the low-voltage tie line switch and the load switch control mechanism, and controls the main transformer low-voltage side incoming switch, the low-voltage tie line switch and the load switch to open.

The logic control module receives signals from the analog input module and the switch input module, executes the power supply recovery logic and the load switching logic, outputs the control signal through the switch output module, and uploads the information to the substation monitoring through the communication module system.

As shown in Figure 2, the power supply system using the network-load coordinated control device includes a single-power incoming line substation A and multi-power incoming line substation B, the main transformer low-voltage side incoming line switch A310, the low-voltage tie line switch LSN, and the network-load coordinated control device , Load switches 2 to 5, single-power incoming line substation A is connected to the 10 kV busbar through the low-voltage side incoming line switch of the main transformer, multi-power incoming line substation B is connected to the 10 kV busbar through the low-voltage tie line switch, and load switches SA2～ One end of SA5 is connected to the load, and the other end is connected to the 10kV busbar. The network-load coordination control device is respectively connected to the single-power incoming line substation, the main transformer low-voltage side incoming line switch A310, the low-voltage tie line switch LSA, the multi-power incoming line substation, and the load The switches SA2-SA5 are connected, and the network-load cooperative control device collects the low-voltage bus voltage of the high-voltage substation, the voltage of the substation with multi-power incoming lines, the position signals of the main transformer low-voltage side incoming line switch and the low-voltage tie line switch, and the main transformer protection action signal, Control the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch cut-off.

The network-load coordination device collects the 10 kV bus voltage of substation A, the incoming line current at the low-voltage side of the main transformer, the position signals of the incoming line switch A310 at the low-voltage side of the main transformer and the low-voltage tie line switch LSA, and the action signal of the main transformer protection device, etc. Control the incoming line switch A310 on the low-voltage side of the main transformer, the low-voltage tie line switch LSA and other 10 kV load switches SA2~SA5, and have the functions of power supply recovery and load switching for low-voltage loads when the main power supply loses voltage. In the network-load coordinated control device, parameters such as power supply recovery input and load switching input control word, whether the 10 kV outgoing line is an important line, voltage setting, post-acceleration overcurrent setting, action delay, and load upper limit can be set. The device has post-acceleration protection function, the power supply recovery action closes on the fault, accelerates to trip the low-voltage tie line switch LSA, and the post-acceleration overcurrent setting can choose to use the time-limited value of the outgoing line switch. This protection is after closing the low-voltage tie line switch LSA Open for a certain period of time, if the post-acceleration protection starts, it will be open until the fault is removed.

The power supply recovery logic of the network-load coordination device includes power supply recovery permission conditions, power supply recovery blocking conditions, and power supply recovery action conditions. The allowable condition of power supply recovery is that when the 10 kV bus of substation A is under voltage, the switch LSA is in place, and other blocking conditions are not met, the power supply recovery action is allowed. The power supply recovery blocking condition is that any one of the conditions of switch LSA closing, substation A main transformer backup protection action, switch LSA jumping abnormally, switch A310 or load switch refusing to trip is met. The operation condition of power supply recovery is that when the 10 kV bus of substation A loses voltage and switch A310 has no current, switch A310 and the outgoing line switch of non-important lines are tripped after a delay, and after the trip is confirmed, the switch LSA is closed after a delay.

The load switching logic of the network-load coordinated control device includes: when the total low-voltage load does not exceed the upper limit of the load before the voltage loss, it will directly enter the power supply restoration process; If the energy storage system is connected to the line, the amount of load shedding can be reduced according to the power and electricity supplied by the energy storage system; The importance level cuts off important lines step by step.

The important line parameters of the network-load coordinated control device can be set as SA2(1), SA3(2), SA4(0), and SA5(0), that is, when the total amount of low-voltage load exceeds the upper limit of the load before the pressure loss, it will be cut off first For non-important lines SA4 and SA5, complete the power supply restoration process. If the load of SA2 and SA3 exceeds the upper limit of load during subsequent operation, SA2 will be cut off first, and then SA3 will be cut off.

During normal operation, substation A uses the 110kV incoming line LA as the main power supply, and the low-voltage tie line is supplied by substation B. The switch LSA is opened, the switches LSN and LSB are closed, and the switch LSA is hot standby and serves as a connection between substations A and B. the disconnection point.

When a fault occurs in the upper-level power grid and the 110 kV incoming line LA loses power or the main transformer differential protection operates, substation A loses the main power supply. At this time, the network-load coordination device detects the loss of voltage of the 10 kV bus and the switch A310 has no current. , the delay re-trip switch A310 to ensure disconnection from the upper-level power grid, and judge whether to cut off non-essential lines according to the logic of load connection cut-off. After confirming that switch AS310 and non-essential lines are cut off, close the switch LSA, and accelerate if it is connected to the fault trip, otherwise the power supply recovery process ends and a new stable power supply network is formed.

It is easy for those skilled in the art to understand that the above descriptions are only preferred embodiments of the present utility model, and are not intended to limit the present utility model. Any modifications and equivalent replacements made within the spirit and principles of the present utility model And improvements, etc., all should be included in the protection scope of the present utility model.

Claims (4)

1. A network-load coordinated control device for low-voltage line power supply recovery, characterized in that it includes an analog input module, a switch input module, a switch output module, a logic control module, and a communication module; the analog input module It is connected with the logic control module; the switch value input module is connected with the main transformer low-voltage side incoming line switch, the control mechanism of the low-voltage tie line switch and the main transformer protection device, and collects the position signals of the low-voltage side incoming line switch and the low-voltage tie line switch, Main transformer protection action signal; the switch output module is connected with the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch control mechanism, and controls the main transformer low-voltage side incoming line switch, low-voltage tie line switch and load switch to open The logic control module receives signals from the analog input module and the switch input module, and after executing the power supply recovery logic and load switching logic, outputs the control signal through the switch output module, and uploads the information to the substation through the communication module surveillance system. 2. A network-load cooperative control device for low-voltage line power supply recovery according to claim 1, characterized in that it also includes a low-voltage bus transformer connected to the analog input module to collect low-voltage from a single power supply incoming line substation bus voltage. 3. A network-load cooperative control device for low-voltage line power supply recovery according to claim 1, characterized in that it also includes a current transformer on the low-voltage side of the main transformer, which is connected to the analog input module to collect single power supply incoming lines The incoming current of the main transformer low-voltage side of the substation. 4. A power supply system adopting the grid-load coordinated control device according to claims 1 to 3, characterized in that it includes a grid-load coordinated control device, a single power supply incoming line substation, a main transformer low-voltage side incoming line switch, and a low-voltage tie line Switches, multi-power incoming line substations, load switches, single power incoming line substations are connected to the 10 kV busbar through the low-voltage side incoming line switch of the main transformer, multi-power supply incoming line substations are connected to the 10 kV busbar through low-voltage tie line switches, load switches One end is connected to the load, and the other end is connected to the 10kV busbar. The network-load coordination control device is respectively connected to the single-power incoming line substation, the main transformer low-voltage side incoming line switch, the low-voltage tie line switch, the multi-power incoming line substation, and the load switch. The network-load cooperative control device collects the low-voltage bus voltage of the high-voltage substation, the voltage of the substation with multi-power incoming lines, the position signals of the main transformer low-voltage side incoming line switch and the low-voltage tie line switch, and the main transformer protection action signal, and controls the main transformer low-voltage side. Line switch, low-voltage tie line switch and load switch.

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