Verification method of main transformer n-1 in medium voltage distribution system based on safe working area

Abstract

A safety working range based (N-1) calibration method for a main transformer of a medium-voltage power distribution system comprises the following steps of inputting structural information of the medium-voltage power distribution system for carrying out topological structure analysis on the medium-voltage power distribution system and carding a connection relation among circuits; carrying out wiring mode analysis on the medium-voltage power distribution system; reading information of a working point of the medium-voltage power distribution system; giving out a safety boundary of a safety working range of the main transformer of the medium-voltage power distribution system; calculating safety distance from the working point of the medium-voltage power distribution system to the safety boundary of the safety working range of the main transformer; judging a running state of the working point of the medium-voltage power distribution system; and giving out a (N-1) calibration result of the main transformer in a research region. According to the calibration method, the working point of the conventional power distribution system can be described from the perspective of a grid structure of the power distribution system and based on a feeder interconnection relation, the boundary of the safety working range of the main transformer of the medium-voltage power distribution system is further described, and the safety distance from the working point of the system to the boundary of the safety working range of the main transformer is calculated. By the calibration method, more comprehensive safety information can be provided, and the calibration method is more suitably used in real-time dispatching operation.

Description

technical field [0001] The invention relates to a power supply security checking method of a distribution network. In particular, it relates to a method for verifying the main transformer N-1 of a medium-voltage power distribution system based on a safe working range. Background technique [0002] As an important link in the production, transmission and use of electric energy, the power distribution system is the link between users and power generation and transmission systems. During distribution system planning, operation and dispatching, the N-1 safety criterion is usually used to evaluate the wiring mode of the distribution system, that is, to check whether the planning and design or operation scheduling scheme of the distribution system meets the N-1 safety criterion. The N-1 safety criterion requires that when the distribution network is in operation, when an independent component (such as the main transformer, feeder, etc.) in the distribution network fails, there wi...

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Problems solved by technology

[0003] However, the topological structure of the power distribution system is changeable and the scale of components is large. The traditional N-1 verification method of the main transformer of the power distribution system performs N-1 verification on the main transformers in the research area one by one, that is, at a given operating point, Assume that each main transformer may fail, and analyze the situation after each main transformer fails, and verify whether the power grid is safe after the main transformer fails through a large number of simulation calculations. The calculation amount is large and the calculation speed is slow. And the simulation results can only give the judgment of safety or unsafety and which main transformers N-1 check fails, it is difficult to give an overall evaluation of the operating state of the system, such as the margin between the operating point of the system and the unsafe operating state , what is the capacity of the operating point beyond the safe value, what is the direction and measure of the preventive control of the operating point

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