An Optimal Load Shedding Method Considering the Impact of Distributed Power

Abstract

The invention discloses an optimized load shedding method with consideration of the influence of a distributed power supply. All nodes in a distribution network upload interruptible load capacities ata current time and load priority levels to a centralized controller at a root node and the centralized controller establishes an optimized load shedding model with consideration of an outer net equivalence according to the uploaded information and a flow restraint; the centralized controller converts a non-linear flow restraint into one in a convex second-order cone mode by means of second-ordercone relaxation and thus calculates an optimized load shedding value with consideration of the distributed power supply output influence rapidly, and issues the information to all node control units;after all nodes perform a load shedding action, a measuring unit monitors whether the node voltages are restored to be in a rated range and determines whether to complete the load shedding process. With the method disclosed by the invention, quick and precise load shedding controlling is realized in a distribution network including lots of distributed power supplies and the voltage of the distribution network is restored to the greatest extent; limit exceeding of the voltage of the distributed power supply is avoided; and thus over-voltage tripping of the distributed power supply caused by theimproper load shedding is avoided.

Description

technical field [0001] The invention relates to the technical field of power system operation and control, in particular to an optimized load shedding method considering the influence of distributed power sources. Background technique [0002] With the formation of the interconnection pattern of regional power grids, the connection between power grids is becoming closer and closer, and the failure of a certain regional power grid may lead to the consequences of "one small change affects the whole body". The essence of safe and stable operation of the power system lies in power balance. When the power transmission network fails and a large power shortage occurs at the receiving end, the system frequency will drop sharply, and the voltage in some areas will also drop sharply, seriously affecting the stability of the power system. In extreme cases, large-scale power outages may occur. At present, a large number of DC transmission processes in my country have been implemented, ...

AI Technical Summary

Problems solved by technology

However, this centralized fixed load shedding scheme cannot cope with changes in system operating conditions, because the decision-making center does not actually consider local real-time voltage, current operating conditions, and interruptible load information; in addition, hierarchical and partitioned grid dispatching The management mode makes the regional distribution network dispatching center only grasp the local real-time status and model data, and it is difficult to quickly and effectively obtain the whole network information, which often results in untimely and inaccurate load shedding decisions.

On the one hand, load fluctuations and the uncertainty of distributed power output in the distribution network make the measurement data of the remote terminal unit RTU inaccurate and the information collection not timely. The protection device tripped and caused a larger area of ​​power outage

On the other hand, the access of a large number of distributed power sources to the distribution network has changed the network topology, and the existence of bidirectional power flows has brought new challenges to the optimization decision-making of emergency load shedding.

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