Probabilistic reliability estimation method and device of active power distribution network

Abstract

The present invention provides a probabilistic reliability estimation method and device of an active power distribution network. The method includes the following steps that: the load power and / or power supply power at each node of a power distribution network system are obtained; random variables composed of the load power and / or power supply power are transformed into first standard normal variables which are unrelated to one another; a point estimation method is adopted to construct a sample matrix corresponding to a random variable space based on the first standard normal variables; and failure mode influence analysis is carried out for the sample matrix, so that the probability density function of a reliability index is obtained. According to the method and device of the invention, a condition that the point estimation method can convert influences on reliability caused by the power supply power of DG (distributed generation) and the load power at each node into a deterministic problem so as to solve the deterministic problem is considered, and therefore, calculation is simple; a condition that Nataf transformation is not limited by the type of input variables, so that the relativity problem of the random variables can be effectively processed; and the point estimation method and the Nataf transformation are combined together, and therefore, the accurate estimation of the probabilistic reliability of the active power distribution network can be realized.

Description

technical field [0001] The invention belongs to the field of power distribution system planning and operation, and in particular relates to a method and device for estimating the probability reliability of an active power distribution network. Background technique [0002] There are many uncertain factors in the actual operation of power distribution system, such as system component failure, load power fluctuation and so on. In recent years, with the gradual maturity of power electronic technology in the application of renewable energy generation, more and more intermittent distributed generation (DG) is connected to the distribution network, which will face more random power during operation. The impact of fluctuations. The probabilistic reliability calculation takes various uncertain factors as input variables, quantitatively analyzes the influence of these random factors on the reliability of distribution network power supply, and evaluates the reliability level of the d...

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Problems solved by technology

Analytical method needs to simplify the research object, and then perform convolution calculation to solve it. The calculation amount is large, and the simplification process will cause certain errors, which is not suitable for analyzing complex problems; Monte Carlo simulation method can directly simulate various uncertain factors , the implementation is simple, but in order to obtain higher precision, a large number of sampling calculations need to be repeated, and there is a contradiction between calculation accuracy and calculation efficiency

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