Load-shedding control method with consideration of system voltage stability after photovoltaic access

Abstract

The invention, which belongs to the technical field of the power system and automation thereof, discloses a load-shedding control method with consideration of system voltage stability after photovoltaic access, so that the adverse influence on high-voltage grid voltage recovery after a fault by large-scale photovoltaic access to the grid is eliminated. An equivalent local grid static voltage stability index of an external network is calculated to determine a voltage instability situation; a dominant factor of voltage instability is identified based on a characteristic change of reactive power absorbing by a photovoltaic aggregation station after the fault; and then load-shedding control strategies are formulated on the condition of using a photovoltaic factor as the dominant instability factor and using a cross-section factor as the dominant instability factor, thereby realizing load-shedding control of the voltage weak node load. Therefore, the power system scheduling operation staff can obtain the inherent operation rule of the photovoltaic access system and the foundation is laid for formulating a load-shedding optimization strategy cooperatively, so that the effectiveness and automation level of secure and stable control of a large grid are improved.

Description

technical field [0001] The invention belongs to the technical field of power systems and automation thereof. More precisely, the invention relates to a load shedding control method that takes into account the system voltage stability after photovoltaics are connected. Background technique [0002] At present, new energy technologies based on wind power and photovoltaics have been widely used. Large-scale photovoltaics are concentrated in areas such as Gobi and deserts. The regional power grid and the long transmission channel will affect the reactive power balance characteristics of the power grid, which will cause large fluctuations in the bus voltage along the way. At the same time, due to the limited reactive power adjustment capability of the photovoltaic power station itself, the inverter link of the photovoltaic power station will lose a part of reactive power, and the reactive power is basically proportional to the active power sent. Once a fault causes a large drop ...

AI Technical Summary

Problems solved by technology

This method aims at the problem that large-scale photovoltaic access to the power grid has an adverse effect on the voltage recovery of the high-voltage power grid after a fault. Changes in power characteristics identify the leading factors of voltage instability, and formulate load shedding control strategies when the instability factors are photovoltaic-dominated and cross-section-dominated, to achieve load shedding control of voltage-weak node loads

Images