CN108631437A - A kind of low-voltage distribution network automatic control system - Google Patents

Abstract

The invention discloses a low-voltage distribution network automation control system, including: a computer, an intelligent terminal, a server, a low-voltage distribution network automation transformation station area and a GSM short message automation subsystem; the low-voltage distribution network automation transformation station area is a management area of the low-voltage distribution network , used to convert the output end of the medium-voltage distribution network into a low-voltage circuit, and perform data detection and set switches on the low-voltage circuit; both the computer and the intelligent terminal are connected to the server signal; the low-voltage distribution network automation transformation station area is connected to the server and GSM SMS respectively Automation subsystem signal connections. The advantage of the present invention is that it realizes the function of multiple remote control operations by the operator on each low-voltage station area, effectively eliminates the unnecessary power outage effect caused by the medium-voltage fault to the low-voltage, and protects the health of the distribution transformer and the safety of the three-phase electrical equipment of the user; According to the composition of load users, personnel can adjust the customized parameters of operation to improve management efficiency and management level.

Description

A low-voltage distribution network automation control system

technical field

The invention relates to the field of electric power, and more specifically, to an automatic control system for a low-voltage distribution network.

Background technique

At present, the automation technology of medium-voltage distribution network is developing rapidly, but there is a lack of solutions for intelligent automation cooperation between medium-voltage and low-voltage networks. The following problems exist in the daily operation between the existing medium-voltage and low-voltage networks: after the automatic operation of the medium-voltage distribution network, when the line of the medium-voltage distribution network fails, the low-voltage main switch cannot cooperate with the change of the operating state of the medium-voltage switch. Automatic control function; resulting in the failure of automatic reclosing after the low-voltage main switch trips under voltage or undervoltage;

Secondly, the switch manufacturers of the low-voltage load master switches currently in operation have different product structures, which brings extremely high operational difficulty and cost pressure to the centralized automation of low-voltage aspects;

In some cases, when the low-voltage main switch encounters under-voltage and under-voltage tripping, it cannot maintain a match with the medium-voltage automation system due to logic matching problems, resulting in long recovery time for power supply, low reliability of power supply, and many complaints from users for long power outages;

The current protection device has a single function and cannot automatically cut off the load when the distribution transformer is running without phase according to the different needs of the actual user end, resulting in long-term phase-loss operation of the transformer, which endangers the health of the distribution transformer and the three-phase electrical equipment of the user, especially the motor. In order to prevent users from compensating and complaining due to burning three-phase electrical equipment of users, the power management agencies in some areas even choose to turn off the protection function of the low-voltage main switch, which brings certain risks to the operation of the power grid.

Contents of the invention

The present invention provides a method for overcoming the above-mentioned defects in the prior art.

In order to solve the problems of the technologies described above, the technical solution of the present invention is as follows:

A low-voltage distribution network automation control system, including: a computer, an intelligent terminal, a server, a low-voltage distribution network automation transformation station area, and a GSM short message automation subsystem;

The low-voltage distribution network automation transformation station area is the management area of the low-voltage distribution network, which is used to convert the output end of the medium-voltage distribution network into a low-voltage circuit, and perform data detection and set switches on the low-voltage circuit;

Both the computer and the intelligent terminal are connected to the server signal;

The low-voltage distribution network automation transformation station area is respectively connected with the server and the GSM short message automation subsystem signal.

The above-mentioned working principle is: the computer and the intelligent terminal are first connected to the server, through which the server controls the low-voltage distribution network automation transformation station area to detect the relevant data of the low-voltage circuit, and after the operation is completed, the relevant information is transmitted to the operator through the GSM SMS automation subsystem On the smart terminal; the operator can also send the operation instruction to the GSM SMS automation subsystem through the GSM network, and the on-site personnel in the low-voltage distribution network automation transformation station area can switch the low-voltage circuit after receiving the operation instruction.

Preferably, the low-voltage distribution network automation transformation station area includes a 10KV/0.4KV transformer, an incoming line side voltage acquisition module, a low voltage load main switch, a CT acquisition module, an outgoing line side voltage acquisition module, a control module and a communication module;

The control module cooperates with other modules in the low-voltage distribution network automation transformation station area to control various low-voltage load master switches with electronic control functions, and can adjust protection parameters according to the rated capacity of the transformer, and according to the type, purpose and method of load users Differentiated protection control scheme settings are made;

Described control module comprises relay protection module and processing module, and control module is connected with communication module signal, and communication module is used for connecting with server and GSM short message automation subsystem;

The control module is also electrically connected with the incoming line side voltage acquisition module, the low voltage load master switch, the CT acquisition module and the outgoing line side voltage acquisition module;

The input end of the 10KV/0.4KV transformer is connected to the external 10KV medium voltage side, and the output end provides a current of 0.4KV and is connected to the input end of the incoming line side voltage acquisition module;

The input end of the low-voltage load master switch is connected with the output end of the incoming line side voltage acquisition module, and the output end is connected with the input end of the CT acquisition module;

The input end of the outgoing line side voltage acquisition module is connected to the output end of the CT acquisition module, and the output end is connected to an external device.

Preferably, the CT module is an electromagnetic current transformer, which is used to convert the large current at the input side into a current with a smaller value through a certain ratio, so as to measure the current value.

Preferably, the communication module is a GSM/GPRS module, which is used for remote information transmission and sending remote instructions to the control module.

Preferably, both the incoming-line-side voltage acquisition module and the outgoing-line-side voltage acquisition module include an A/D converter for reading voltage data after converting an analog signal in the grid system into a digital signal.

Compared with the prior art, the beneficial effects of the technical solution of the present invention are:

The low-voltage distribution network automation control system sets up low-voltage distribution network automation to transform the station area, and integrates with the server to realize GPRS/GSM communication, so that the low-voltage distribution network automation control system can realize multiple remote control functions for each low-voltage station area, effectively eliminating the middle Protect the health of the distribution transformer and the safety of the user's three-phase electrical equipment;

The operator obtains the operation status of the low-voltage distribution network automation transformation station area at any time through the GSM SMS automation subsystem, and adjusts the customized parameters of the operation according to the composition of the load users, which helps to improve management efficiency and management level;

Operators can choose whether to use leakage and grounding protection according to the needs of the user type, and effectively eliminate the harm caused by the failure of the low-voltage distribution network to the power grid.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

Figure 1 is a schematic diagram of a low-voltage distribution network automation control system.

Figure 2 is a schematic diagram of the low-voltage distribution network automation transformation station area.

Detailed ways

The accompanying drawings are for illustrative purposes only and cannot be construed as limiting the patent;

In order to better illustrate this embodiment, some parts in the drawings will be omitted, enlarged or reduced, and do not represent the size of the actual product;

For those skilled in the art, it is understandable that some well-known structures and descriptions thereof may be omitted in the drawings.

The technical solutions of the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Example 1

A low-voltage distribution network automation control system, as shown in Figure 1, includes: a computer, an intelligent terminal, a server, a low-voltage distribution network automation transformation station area, and a GSM short message automation subsystem;

The low-voltage distribution network automation transformation station area is the management area of the low-voltage distribution network, which is used to convert the output end of the medium-voltage distribution network into a low-voltage circuit, and perform data detection and set switches for the low-voltage circuit;

Both the computer and the smart terminal are connected to the server signal;

The low-voltage distribution network automation transformation station area is respectively connected to the server and the GSM SMS automation subsystem signal.

In this embodiment, as shown in Figure 2, the low-voltage distribution network automation transformation station area includes a 10KV/0.4KV transformer, a voltage acquisition module on the incoming line side, a low-voltage load switch, a CT acquisition module, a voltage acquisition module on the outgoing line side, and a control module and communication modules;

The control module includes a relay protection module and a processing module, the control module is connected to the communication module for signals, and the communication module is used to connect with the server and the GSM short message automation subsystem;

The control module is also electrically connected with the incoming line side voltage acquisition module, the low voltage load master switch, the CT acquisition module and the outgoing line side voltage acquisition module;

The input terminal of the 10KV/0.4KV transformer is connected to the external 10KV medium voltage side, and the output terminal provides 0.4KV current and is connected to the input terminal of the voltage acquisition module on the incoming line side;

The input end of the low-voltage load master switch is connected to the output end of the voltage acquisition module on the incoming line side, and the output end is connected to the input end of the CT acquisition module;

The input end of the voltage acquisition module on the outlet side is connected to the output end of the CT acquisition module, and the output end is connected to an external device.

In this embodiment, the CT module is an electromagnetic current transformer.

In this embodiment, the communication module is a GSM/GPRS module, which is used to transmit remote information and send remote commands to the control module.

In this embodiment, both the voltage acquisition module at the incoming line side and the voltage acquisition module at the outgoing line side include an A/D converter.

The detailed working principle of the low-voltage distribution network automation control system in this embodiment is as follows:

The purpose of the low-voltage distribution network automation control system is to match the state changes of the power grid caused by medium-voltage faults, so that the low-voltage load main switch can automatically open when the medium-voltage fault occurs, and the low-voltage main switch completes automatic switching after automatic troubleshooting. Closing operation; at the same time, according to the characteristics of low-voltage equipment, it can have the functions of ground fault discrimination and leakage discrimination, trigger the corresponding protection trip operation, and play the role of protecting the transformer and isolating faults.

In the low-voltage distribution network automation transformation station area, the 10KV/0.4KV transformer first converts the external 10KV medium voltage to 0.4KV low voltage, and then through the outgoing line side voltage acquisition module, incoming line side voltage acquisition module and CT acquisition module. Real-time detection of voltage and current for low-voltage electricity, judgment of dangerous conditions such as voltage loss/undervoltage, overvoltage, leakage, zero break, grounding, short circuit, overload, etc., and protection through the low-voltage load master switch.

The relay protection module receives data and commands through the communication module, and sends data and GSM information through the GPRS/GSM communication module.

The processing module realizes multiple functions, including: adjusting protection parameters, and setting differentiated protection control schemes according to different types, uses and methods of load users;

When the fault type of grounding or leakage occurs on the low-voltage line, the operator can customize the "Enable" or "Exit" control module to control the shunt tripping of the low-voltage load master switch through the processing module; when set to "Enable" When the type of grounding or leakage fault occurs, the operator sets the output timing of the low-voltage automatic control module to the control action of the low-voltage load switch shunt trip to a delay time that is greater than 0 and can be customized, that is, within the discrimination time, if There is a delay time, and it is necessary to wait for the delay time before outputting the control action of shunt tripping;

After the control module has successfully output the control action of the shunt tripping of the low-voltage load switch, the processing module can customize whether it needs to perform a reclosing operation of the switch; it can independently output whether to output the first or second reclosing operation according to the needs The operation is set as "input" or "exit", and the delay time of the action can be set each time;

The processing module has the functions of the typical current time type, voltage time type and voltage current type distribution network protection device of the medium voltage protection device. Both sides of the switch are lower than the set value and there is no flow, and it will open after reaching the delay (the set value, delay action time, and whether to input can be set); the switch is in the closing position, and both sides of the switch are less than the set value, Open after the delay is reached (set value, delay action time, input or not can be set, and df/dt lock can be set); the switch is in the close position, and the voltage on either side of the switch is greater than the set value, after the delay is reached Opening (fixed value, delay action time, input or not can be set, and df/dt lock can be set); the switch is in the minute position, any side is greater than the set value, and the switch is closed after the delay is reached; the switch is in the minute position, If the pressure on both sides remains above 20S, it is confirmed that the switch is in the ready state, and the closing is delayed after the pressure loss on one side;

Residual voltage blocking: When jumping, the voltage on either side reaches the residual voltage setting value. Keep above 50MS, and within 1 hour of residual pressure discrimination time. The device no longer closes when there is pressure on the opposite side. The residual voltage discrimination time is generally less than the voltage closing time and the one-sided loss of voltage closing time;

Quick-break lockout: In order to prevent wrong judgment caused by inrush current, under the function of voltage and current, tripping is not allowed when the current is greater than the quick-break current;

Closing lock state. When the low-voltage load master switch is closed with pressure, the low-voltage automatic control module triggers the closing lock within the time for voltage loss discrimination, overcurrent acceleration discrimination, grounding discrimination, and leakage discrimination. When the low-voltage load main switch is in the jump state, if there is residual voltage on any side of the voltage and it remains above 50MS, and it disappears within the residual voltage discrimination time, the low-voltage load switch will not close when there is voltage on the opposite side (residual voltage discrimination The time is generally less than the closing time with pressure and the closing time when one side loses pressure); the residual voltage lockout does not allow automatic reset, and the residual voltage reset condition is to meet the switch closing position + pressure on either side, two pressures for 20S, and the locking side There are any one of the 4 conditions of press close and button reset.

The server, communication module and processing module cooperate to enable operators to realize the following functions on the low-voltage distribution network automation transformation station remotely through computers and smart terminals:

Through low-voltage distribution network automation transformation of the processing module and GSM SMS automation subsystem of the station area, real-time online monitoring of electrical parameters such as current, voltage, frequency, power, power factor, electricity, and current unbalance rate;

The processing module will change the opening and closing position of the low-voltage load switch; and send the information on load state transformation such as overload, grounding, leakage, short circuit, overvoltage and undervoltage, and loss of voltage to the WEB server through the GSM SMS automation subsystem. Send it to the designated maintainer through the GSM SMS network;

The processing module can preset the alarm number, and the preset alarm number can also modify the setting value on the module by sending a text message modification command to the number on the low-voltage automatic control module;

Remote control opening and closing control operation, if necessary, can be dispatched by letting the background server use GPRS communication to send an opening and closing operation command to the low-voltage automatic control module in the station area.

The communication modules in the low-voltage distribution network automation transformation station area include GPRS and GSM communication modes. The GPRS mode is used for the communication of data and control commands between the server and the reformed background area; the GSM mode is specially designed for the different management responsible personnel of each low-voltage station area, so that the specific responsible person can communicate with the station with a relatively poor signal. The district can still carry out the remote control operation to the station district in time through the short message.

After obtaining the permission to use, the operator can access the server through a computer or smart terminal to view the collected data information and generated data, such as data analysis tables and station area operation status tables.

Apparently, the above-mentioned embodiments of the present invention are only examples for clearly illustrating the present invention, rather than limiting the implementation of the present invention. For those of ordinary skill in the art, other changes or changes in different forms can be made on the basis of the above description. It is not necessary and impossible to exhaustively list all the implementation manners here. All modifications, equivalent replacements and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the claims of the present invention.

Claims (5)

1. A low-voltage distribution network automation control system is characterized in that, comprising: computer, intelligent terminal, server, low-voltage distribution network automation transformation station area and GSM short message automation subsystem; The low-voltage distribution network automation transformation station area is the management area of the low-voltage distribution network, which is used to convert the output end of the medium-voltage distribution network into a low-voltage circuit, and perform data detection and set switches on the low-voltage circuit; Both the computer and the intelligent terminal are connected to the server signal; The low-voltage distribution network automation transformation station area is respectively connected with the server and the GSM short message automation subsystem signal. 2. The low-voltage distribution network automation control system according to claim 1, characterized in that, the low-voltage distribution network automation transformation station area includes a 10KV/0.4KV transformer, a voltage acquisition module on the incoming line side, a low-voltage load master switch, and a CT acquisition Module, outlet side voltage acquisition module, control module and communication module; Described control module comprises relay protection module and processing module, and control module is connected with communication module signal, and communication module is used for connecting with server and GSM short message automation subsystem; The control module is also electrically connected with the incoming line side voltage acquisition module, the low voltage load master switch, the CT acquisition module and the outgoing line side voltage acquisition module; The input end of the 10KV/0.4KV transformer is connected to the external 10KV medium voltage side, and the output end provides a current of 0.4KV and is connected to the input end of the incoming line side voltage acquisition module; The input end of the low-voltage load master switch is connected with the output end of the incoming line side voltage acquisition module, and the output end is connected with the input end of the CT acquisition module; The input end of the outgoing line side voltage acquisition module is connected to the output end of the CT acquisition module, and the output end is connected to an external device. 3. The low-voltage distribution network automation control system according to claim 2, wherein the CT module is an electromagnetic current transformer. 4. The low-voltage distribution network automation control system according to claim 2, wherein the communication module is a GSM/GPRS module, which is used for remote information transmission and sending remote commands to the control module. 5. The low-voltage distribution network automation control system according to claim 2, characterized in that, both the incoming-line-side voltage acquisition module and the outgoing-line-side voltage acquisition module include A/D converters.