Network voltage reactive-power compound coordination control system and method for new energy power generation

Abstract

The invention belongs to the technical field of voltage reactive-power control of grid-connected operation of new energy power generation with wind power, photovoltaic and the like in electric engineering, and particularly relates to a network voltage reactive-power compound coordination control system and method for new energy power generation. A silent dynamic var generator, a dynamic voltage restorer and an existing transformer station voltage reactive-power comprehensive control device are combined to form a dynamic voltage reactive-power control system, a voltage reactive-power plane is divided into sixteen control areas by the aid of the optimum voltage reactive-power operating state and the unit adjustment variable quantity of a capacitor bank and an on-load voltage regulating transformer tap, and each area corresponds a corresponding control strategy. Network voltage reactive-power frequent fluctuation caused by wind power and photovoltaic intermittent power generation is restrained by coordinately controlling the dynamic voltage reactive-power control system, network voltage reactive-power comprehensive control level is improved, practical engineering application is facilitated, and key technical support is provided for voltage reactive-power comprehensive control of new energy grid-connected power generation in a smart grid.

Description

technical field [0001] The invention belongs to the technical field of voltage and reactive power control for grid-connected power generation and operation of new energy sources such as wind power and photovoltaics in electrical engineering, and in particular relates to a grid voltage and reactive power composite coordinated control system and method including new energy power generation. Background technique [0002] The basic execution unit of the grid automatic voltage control system (Automatic Voltage Control System—AVC) is the substation voltage and reactive power comprehensive control device (Voltage and Reactive Power Control System—VQC). The VQC device is mainly composed of capacitor banks and on-load tap changer transformers. The VQC system coordinates and controls the switching of the capacitor bank and the transformation of the on-load tap changer (On Load Tap Changer—OLTC) through the control strategy of the nine-zone diagram to realize the comprehensive control o...

AI Technical Summary

Problems solved by technology

However, the main problems in the existing VQC device and the control strategy of the "nine-area map" are: the adjustment of the on-load tap changer transformer tap and the capacitor bank are adjusted in steps, and the adjustment steps are relatively large, making it difficult to achieve precise control. In addition, when the control strategy of the nine-zone diagram is adopted, oscillations will occur in some control areas, resulting in the traditional VQC device not being able to effectively meet the voltage and reactive power fluctuations caused by intermittent new energy generation such as wind power and photovoltaics when they are connected to the grid.

However, with the large-scale development of wind power, photovoltaic power generation and other new energy power generation and the continuous improvement of users' requirements for power quality, intermittent new energy power generation represented by wind power and photovoltaic power generation will inevitably lead to energy pressure while relieving energy pressure. Frequent voltage fluctuations, voltage flicker and other power quality problems have seriously affected the normal operation of the grid automatic voltage control system

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