Voltage optimization method for flexible interconnection power distribution system

Abstract

The invention provides a voltage optimization method for a flexible interconnection power distribution system. The method comprises the following steps: building a voltage optimization model based on distribution robust opportunity constraint, and constructing an uncertainty probability set for a random variable through a Wasserstein distance; for an objective function and constraint conditions in the model, setting the objective function by taking minimum network loss and minimum voltage deviation as objectives, meanwhile, setting power balance constraint, substation outlet power constraint, CB and OLTC operation constraint and flexible interconnection device operation constraint as hard constraint conditions, and setting node voltage and branch power as opportunity constraint conditions of the model; and constructing a voltage optimization model. The built model is difficult to directly solve, so that the mixed integer random second-order cone programming algorithm is used for solving. According to the optimization model and the solving method thereof, the uncertainty of the source load can be effectively handled, so that the operation safety of the power distribution system is guaranteed.

Description

technical field [0001] The invention belongs to the technical field of electric power dispatching, and in particular relates to a two-stage voltage optimization method of day-ahead and day-day in a flexible interconnection power distribution system considering source-load uncertainty. Background technique [0002] The output of distributed generation (DG) and the load demand of electrical equipment have strong uncertainties, that is, the double uncertainty of source and load, which is easy to cause the voltage limit of the distribution network. The traditional distribution network suppresses voltage fluctuations by setting OLTC (on-load tap changer) and CB (capacitor bank), but both OLTC and CB belong to reactive power regulation, and the response speed is slow. Accurate, high-frequency response to voltage fluctuations. For this reason, a flexible interconnection technology that interconnects multiple feeders in the distribution network through a flexible interconnection de...

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Problems solved by technology

One of them is based on a deterministic dispatching model, which can effectively reduce the impact of source-load uncertainty on system operation; however, with the increase of DG and load scale in today's distribution network, the source-load uncertainty increases, so This deterministic-based scheduling model is increasingly difficult to cope with

Another way of thinking is the scheduling model based on uncertainty, and the existing uncertainty scheduling model includes two kinds of robust optimization model and chance-constrained programming model; the robust optimization model pursues the worst-case The optimal solution of the objective function, so that the solution or decision to be obtained satisfies all the constraints, but because of this characteristic, the control strategy obtained through the robust optimization model is generally too conservative, which increases the restrictions on production and living power consumption, which is not conducive to Economic development; while the chance-constrained programming model assumes that the random variable obeys an exact probability distribution, so that in the optimization process, the probability of making a decision that satisfies the constraints is first calculated. As long as the probability is not lower than the specified confidence level, the decision-making is allowed Decision-making breaks through the constraints; however, in the actual power distribution system, for a large number of complex scenarios, it is difficult to obtain the exact probability distribution function of the uncertain variable, which makes it difficult for the practical application of the chance constrained programming model

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