Risk monitoring method for over-limit current protection of urban power grid including charging and discharging stations for electric vehicles

Abstract

The invention belongs to the field of power system protection and control and particularly relates to a current protection and threshold crossing risk monitoring method for an urban power grid including EV (electric vehicle) charge-discharge stations. Probability distribution of discharge powers of the EV charge-discharge stations is formed on basis of charge-discharge data information of the EV charge-discharge stations; short circuit current probability distribution of each current protector is calculated through Gram-Charlier series and a semi-invariant; a short circuit current threshold crossing severity index is calculated through a utility theory; current protection and threshold crossing risk indexes of the urban power grid including the EV charge-discharge stations are then calculated. According to the method, risk assessment is performed by a probabilistic power flow method on basis of the utility theory and a risk theory; normal current protection is effectively guaranteed for the urban power grid including EV charge-discharge stations, and the urban power grid can run safely and reliably.

Description

technical field [0001] The invention belongs to the field of power system protection and control, and in particular relates to a method for monitoring the risk of over-limit current protection of an urban power grid including electric vehicle charging and discharging stations. Background technique [0002] As a representative of new energy vehicles, electric vehicles have obvious advantages in terms of environmental protection, cleanliness, and energy saving compared with traditional vehicles powered by gasoline combustion. Electric vehicles, which represent the development direction of a new generation of energy-saving and environmentally friendly vehicles, have gradually been popularized and applied all over the world. The energy supply required for their operation is realized by the supporting charging and discharging devices and charging and discharging stations. After the electric vehicle charging and discharging station is connected to the power network as a distribute...

AI Technical Summary

Problems solved by technology

After the electric vehicle charging and discharging station is connected to the power network as a distributed micro-energy storage unit, the distribution network will change from a radial network to a complex network of distributed and controllable micro-energy storage and user interconnection, and its operating characteristics will change, affecting the power grid. safe and economical operation of

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