Active distribution network dynamic simulation method based on multi -level optimization chase and changing iteration method

Abstract

The invention discloses a dynamic simulation method for an active distribution network based on a multi-level optimization and chasing variational iterative method. First, the variational iteration algorithm is improved in two aspects: on the one hand, on the right side of the correction functional, the The approximate analytical solution has been obtained; on the other hand, differential equations with higher coupled frequencies are preferentially calculated. Therefore, an optimization chasing variational iterative method with faster offline convergence is proposed. Secondly, based on this method, the approximate analytical solutions corresponding to the photovoltaic system in the active distribution network and the dynamic elements in the synchronous generator system are obtained. Subsequently, a multi-stage mechanism is introduced, that is, the approximate analytical solution is applied on continuous time intervals, which breaks through the limited convergence region of the original variational iteration method, so that it can be applied to active distribution systems that require accurate solutions in larger time spans. power grid simulation. This method is faster than the traditional numerical integration method.

Description

technical field [0001] The invention discloses a dynamic simulation method of an active distribution network based on a multi-level optimization and chasing variational iterative method, and belongs to the technical field of power system simulation and analysis. Background technique [0002] In recent years, renewable energy is moving towards the main body of the future global energy structure. The large-scale access of distributed renewable energy such as photovoltaics to the distribution network has brought changes in power flow and voltage distribution to the distribution network, making the single-source radiation distribution network develop towards a multi-source active distribution network. . The distributed renewable power source with high penetration rate will bring many power system problems to the distribution network. For example, the photovoltaic power station is a highly nonlinear system, and the power it provides is random and uncertain, which will affect the...

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Problems solved by technology

[0003] However, the research work on dynamic simulation of active distribution network with high penetration distributed generation faces many technical difficulties and challenges

For the high-dimensional nonlinear system of the active distribution network, the traditional explicit and implicit integration algorithms, on the one hand, in the dynamic simulation operation, the simulation efficiency is low due to too many iterations; on the other hand, in a variety of distributed power In the computing environment of the rigid differential system of the connected active distribution network, the traditional integral algorithm needs to match the rigid characteristics with a smaller step size, so it is difficult to balance the computational efficiency and numerical stability of the dynamic simulation

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