Power distribution network equipment fault processing method
Technical Field
The invention relates to the field of power distribution networks, in particular to a power distribution network equipment fault processing method.
Background
When a power distribution network has a fault, how the distributed power supply operates directly influences the execution of a fault recovery strategy, and when the fault occurs, after a power grid containing equipment such as a terminal or a local device is separated from a public power grid, the power grid performs island operation.
The existing management mode is relatively disordered and lacks relevance to the management of industrial equipment, so that the power supply guarantee and the load recovery of equipment such as a terminal, a local device and the like are relatively passive when a fault occurs.
Disclosure of Invention
In order to solve the defects and shortcomings in the prior art, the invention provides a power distribution network equipment fault processing method which comprises the following steps.
S1, configuring terminal association information.
(1) Establishing a directed association list for each terminal, wherein the list comprises all adjacent terminals connected with the terminal by feeders, and the list comprises all forward terminals, backward terminals and parallel terminals associated with the terminal, wherein the current direction of the feeder from the forward terminal to the terminal is the same as the current direction of the feeder from the terminal to the next terminal, the current direction of the feeder from the backward terminal to the terminal is opposite to the current direction of the feeder from the terminal to the next terminal, and the parallel terminals and the terminal have the same backward terminals.
(2) And determining the power flow direction of the whole network, and regarding any distributed power supply as an origin point for the network containing multiple power supplies, wherein the power flow direction of the whole network is the power direction for supplying power from the origin point to the whole network.
And S2, recovering the power distribution network fault.
The fault recovery steps of the power distribution network containing the distributed power supply are as follows.
(1) After a fault occurs, if the distributed power supply on the fault feeder line is a non-black start distributed power supply, directly tripping off an outlet breaker of the distributed power supply; and for the black start distributed power supply, a grid-connected circuit breaker is disconnected, and an island operation mode of a circuit breaker interface is adopted to supply power to local users. And when the capacity of the black-start distributed power supply is smaller than the load power of the local user, carrying out load shedding operation. The distributed power sources on the non-faulty feeders can continue to remain in grid-tied operation.
(2) After the fault is located, searching for a power-losing area, receiving an instruction of a local device by a terminal, diagnosing the fault area by combining a corresponding directed association list and the whole network power flow direction, informing the local device after the diagnosis is finished, tripping off all switches around the fault by the local device, simultaneously detecting an operation result, if the tripping is unsuccessful, expanding an isolation range by cooperating with other local devices, realizing the recovery of power supply of a fault upstream area by closing a head end outlet breaker switch, and simultaneously recovering the power supply of a fault downstream by closing a connection switch.
The local device at each switch of the feeder line acquires current data, when the line is short-circuited, the local device judges short-circuit faults, and at the line outlet, the local device forms a public tripping signal to trip off the breaker; all terminals acquire the fault information of the local devices, and the fault positions are judged by combining the information acquired by the terminals of the adjacent switches; the local device disconnects the switches at two ends of the fault according to the judgment result of the terminal, realizes the isolation of the fault area and informs other local devices of the isolation result; after the isolation is successful, the local device closes the head-end switch and the interconnection switch by combining the locking information, and the power supply of the non-fault area is recovered.
(3) If the network has unrecovered area, go to step (4), otherwise go to step (5).
(4) And (4) considering all black start distributed power supplies on the fault feeder line, searching a recovery path for the unrecovered area, if the path is found, entering a multi-user island operation mode, and otherwise, maintaining the current operation state.
(5) And performing synchronous operation on all the non-black start distributed power supplies in the network, and connecting the grid again. At this stage, the optimal switching strategy is continuously searched, if the switching state changes, the switching state is adjusted after the grid connection is finished, otherwise, the current state is kept.
(6) And after the fault is cleared, the operation mode before the fault is recovered.
And S3, recovering the terminal load.
(1) And monitoring the bus frequency, voltage, active power, reactive power and terminal running state of the system in real time, and actively responding to the input switch by the terminal when the frequency or voltage of the system is abnormal to a terminal response action value due to disturbance.
(2) The electric energy meter acquires terminal capacity information participating in active response, calculates a load recovery sensitivity index according to local frequency, voltage, active power and reactive power of each bus provided with a switching device, and uploads the capacity information and the load recovery sensitivity index to a coordination center.
(3) Different local devices acquire local state information quantity of frequency, voltage, active power, reactive power and the like in real time, and the current response load priority is calculated. And when the frequency or voltage value reaches the action value of the device, determining the load amount required to be put into the device under the current working condition according to the response load priorities of different buses. And calculating the optimized load recovery amount by combining the terminal response information and the load recovery sensitivity index, and updating the load recovery strategy.
(4) And transmitting the optimized load recovery strategy to each local device. And the local device receives the instruction, updates the action value of each round, and puts the load after certain time delay.
Further, the power distribution network recovers from the fault, and the method further comprises the following steps.
If the terminal detects that the forward terminal has a forward overcurrent action sign, the terminal judges that the terminal is a non-fault area, if the terminal detects that the forward terminal has a backward overcurrent protection action and does not detect that other terminals have forward overcurrent protection actions, the terminal judges that the terminal is a fault area, informs the local device to execute a switch tripping command to isolate faults, and simultaneously sends a switch joint debugging command to other terminals.
Further, the power distribution network recovers from the fault, and the method further comprises the following steps.
If the terminal detects that the backward terminal has a backward overcurrent action mark, the terminal judges the terminal to be a non-fault area, if the terminal detects that the backward terminal has a forward overcurrent protection action and does not detect that other terminals have backward overcurrent protection actions, the terminal judges the terminal to be a fault area, informs the local device to execute a switch tripping command to isolate faults, and simultaneously sends a switch joint debugging command to other terminals.
The method for processing the faults of the power distribution network equipment has high automatic operation level, can realize remote control and real-time detection, automatically completes fault detection and isolation through joint debugging of feeder equipment based on the associated configuration of the equipment, and realizes quick recovery of equipment load through an optimized load recovery strategy.
Drawings
Fig. 1 is a flowchart of a method for processing a fault of a power distribution network device according to the present invention.
Detailed Description
As shown in fig. 1, a method for processing a fault of a power distribution network device according to the present invention includes.
S1, configuring terminal association information.
(1) Establishing a directed association list for each terminal, wherein the list comprises all adjacent terminals connected with the terminal by feeders, and the list comprises all forward terminals, backward terminals and parallel terminals associated with the terminal, wherein the current direction of the feeder from the forward terminal to the terminal is the same as the current direction of the feeder from the terminal to the next terminal, the current direction of the feeder from the backward terminal to the terminal is opposite to the current direction of the feeder from the terminal to the next terminal, and the parallel terminals and the terminal have the same backward terminals.
(2) And determining the power flow direction of the whole network, and regarding any distributed power supply as an origin point for the network containing multiple power supplies, wherein the power flow direction of the whole network is the power direction for supplying power from the origin point to the whole network.
And S2, recovering the power distribution network fault.
The fault recovery steps of the power distribution network containing the distributed power supply are as follows.
(1) After a fault occurs, if the distributed power supply on the fault feeder line is a non-black starting distributed power supply, in order to ensure the electric energy quality, an outlet breaker of the distributed power supply is directly tripped; and for the black start distributed power supply, a grid-connected circuit breaker is disconnected, and an island operation mode of a circuit breaker interface is adopted to supply power to local users. And when the capacity of the black-start distributed power supply is smaller than the load power of the local user, carrying out load shedding operation. The distributed power sources on the non-faulty feeders can continue to remain in grid-tied operation.
(2) After the fault is located, searching for a power-losing area, receiving an instruction of a local device by a terminal, diagnosing the fault area by combining a corresponding directed association list and the whole network power flow direction, informing the local device after the diagnosis is finished, tripping off all switches around the fault by the local device, simultaneously detecting an operation result, if the tripping is unsuccessful, expanding an isolation range by cooperating with other local devices, realizing the recovery of power supply of a fault upstream area by closing a head end outlet breaker switch, and simultaneously recovering the power supply of a fault downstream by closing a connection switch.
The local device at each switch of the feeder line acquires current data, when the line is short-circuited, the local device judges short-circuit faults, and at the line outlet, the local device forms a public tripping signal to trip off the breaker; all terminals acquire the fault information of the local devices, and the fault positions are judged by combining the information acquired by the terminals of the adjacent switches; the local device disconnects the switches at two ends of the fault according to the judgment result of the terminal, realizes the isolation of the fault area and informs other local devices of the isolation result; after the isolation is successful, the local device closes the head-end switch and the interconnection switch by combining the locking information, and the power supply of the non-fault area is recovered.
(3) If the network has unrecovered area, go to step (4), otherwise go to step (5).
(4) And (4) considering all black start distributed power supplies on the fault feeder line, searching a recovery path for the unrecovered area, if the path is found, entering a multi-user island operation mode, and otherwise, maintaining the current operation state.
(5) And performing synchronous operation on all non-black start distributed power supplies (including an island operation unit and a tripped distributed power supply unit) in the network, and connecting the network again. At this stage, the optimal switching strategy is continuously searched, if the switching state changes, the switching state is adjusted after the grid connection is finished, otherwise, the current state is kept.
(6) And after the fault is cleared, the operation mode before the fault is recovered.
And S3, recovering the terminal load.
(1) And monitoring the bus frequency, voltage, active power, reactive power and terminal running state of the system in real time, and actively responding to the input switch by the terminal when the frequency or voltage of the system is abnormal to a terminal response action value due to disturbance.
(2) The electric energy meter acquires terminal capacity information participating in active response, calculates a load recovery sensitivity index according to local frequency, voltage, active power and reactive power of each bus provided with a switching device, and uploads the capacity information and the load recovery sensitivity index to a coordination center.
(3) Different local devices acquire local state information quantity of frequency, voltage, active power, reactive power and the like in real time, and the current response load priority is calculated. And when the frequency or voltage value reaches the action value of the device, determining the load amount required to be put into the device under the current working condition according to the response load priorities of different buses. And calculating the optimized load recovery amount by combining the terminal response information and the load recovery sensitivity index, and updating the load recovery strategy.
(4) And transmitting the optimized load recovery strategy to each local device. And the local device receives the instruction, updates the action value of each round, and puts the load after certain time delay.
Further, the power distribution network recovers from the fault, and the method further comprises the following steps.
If the terminal detects that the forward terminal has a forward overcurrent action sign, the terminal judges that the terminal is a non-fault area, if the terminal detects that the forward terminal has a backward overcurrent protection action and does not detect that other terminals have forward overcurrent protection actions, the terminal judges that the terminal is a fault area, informs the local device to execute a switch tripping command to isolate faults, and simultaneously sends a switch joint debugging command to other terminals.
Further, the power distribution network recovers from the fault, and the method further comprises the following steps.
If the terminal detects that the backward terminal has a backward overcurrent action mark, the terminal judges the terminal to be a non-fault area, if the terminal detects that the backward terminal has a forward overcurrent protection action and does not detect that other terminals have backward overcurrent protection actions, the terminal judges the terminal to be a fault area, informs the local device to execute a switch tripping command to isolate faults, and simultaneously sends a switch joint debugging command to other terminals.
The terminal can be various electric equipment except local equipment in the power distribution network, such as primary equipment, secondary equipment and the like.
The method for processing the faults of the power distribution network equipment has high automatic operation level, can realize remote control and real-time detection, automatically completes fault detection and isolation through joint debugging of feeder equipment based on the associated configuration of the equipment, and realizes quick recovery of equipment load through an optimized load recovery strategy.
The above embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and the scope of the present invention is defined by the claims. Various modifications and equivalents may be made by those skilled in the art within the spirit and scope of the present invention, and such modifications and equivalents should also be considered as falling within the scope of the present invention.