Double-time-scale distributed voltage control method and system for three-phase unbalanced active power distribution network

Abstract

The invention provides a double-time-scale distributed voltage control method and system for a three-phase unbalanced active power distribution network. The method comprises the following steps: constructing a mathematical model for realizing multi-target voltage control of an unbalanced tree-shaped power distribution system; dividing a voltage control problem into a fast time scale optimization problem and a slow time scale optimization problem by using a double-time scale optimization framework based on model predictive control, and respectively processing the two optimization problems; andrealizing distributed voltage control by using an alternating direction multiplier method. According to the scheme, devices with different time characteristics are adjusted respectively, the service life of the devices is prolonged, and better economical efficiency is achieved.

Description

technical field [0001] The disclosure belongs to the technical field of active distribution network voltage control, and in particular relates to a dual-time-scale distributed voltage control method and system for a three-phase unbalanced active distribution network. Background technique [0002] The statements in this section merely provide background information related to the present disclosure and do not necessarily constitute prior art. [0003] In recent years, the environmental problems caused by the extensive use of fossil fuels have become more and more serious, and they are also facing the problem of worrying reserves. Therefore, the development and utilization of renewable and clean energy have received extensive attention. The integration of distributed power sources based on renewable energy such as photovoltaics and wind power can well alleviate human dependence on fossil fuels, and meet the growing demand for electricity while achieving environmental friendlin...

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Problems solved by technology

Because the randomness and uncertainty of renewable energy may lead to voltage fluctuations, at the same time, the reverse power flow caused by a high proportion of new energy access may also cause serious voltage rise problems

[0004] Although a lot of research on voltage control has been done at home and abroad, most of them are based on the three-phase balanced system, relying on the single-phase equivalent model, which is not applicable to the three-phase unbalanced system

However, due to uneven single-phase loads, non-equilibrium conductor spacing, and unbalanced power sources, the distribution network itself is inherently unbalanced.

Existing methods cannot efficiently control the voltage of an unbalanced system

[0005] At the same time, with the increasing popularity of distributed systems in distribution networks, some major defects in traditional centralized control methods are exposed

First of all, the large-scale access of devices such as distributed power sources and controllable loads will greatly increase the information that the central controller and communication network need to collect and process, which will easily lead to system failures

Secondly, since the centralized method needs to collect the data of the whole system, the privacy information of the distributed power source is difficult to be protected, which may bring trouble to its owner

[0006] The voltage control devices in the distribution network have different time characteristics and should be coordinated and operated on different time scales, but most of the existing control methods are designed on the same time scale, and the economy needs to be improved. Unbalanced active distribution network Lack of cost-effective distributed voltage control strategies

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