Voltage stability evaluation method for integrated transmission and distribution network based on distributed computing

Abstract

The invention discloses a power transmission-distribution network integrating voltage stability assessment method based on distributed calculation. The power transmission-distribution network integrating voltage stability assessment method based on distributed calculation comprises the following steps: (A) defining loads and generation increase modes of a power transmission network and a power distribution network, and resolving the global voltage stability assessment problem of the power transmission network and the power distribution network into three parts, namely an independent power transmission network calculation sub-problem, an independent power distribution network calculation sub-problem and common connection point information interaction; (B) carrying out continuous power flow prediction by the power transmission network employing a tangent prediction method, calculating various node state variables, various common connection point state variables and predicted values of load parameters of the power transmission network, and judging whether the tangent slope symbols of front and rear points of a P-V curve are opposite or not; and (C) finishing continuous power flow correction link calculation by distributed alternate iteration of the power flow of the power transmission network and power distribution network, and judging whether the power flow meets the convergence condition of distributed calculation or not, if so, turning to the step (B), or else, continuing the step (C). Therefore, distributed calculation of the whole power network load margin is realized.

Description

technical field [0001] The invention relates to an integrated voltage stability evaluation method of a transmission and distribution network based on distributed computing. Background technique [0002] The current voltage stability assessment of the power system separates the transmission network from the distribution network, resulting in low accuracy of the assessment results. With the transformation of the distribution network to an active distribution network containing a large number of different types of distributed power sources, the distribution network becomes an active network, which changes the power flow distribution between the transmission and distribution networks, and the distribution network is no longer suitable for simple equivalence. For the load power, the reactive power and voltage characteristics of distributed power sources need to be strictly taken into account. Therefore, the traditional way of evaluating the voltage stability of the transmission n...

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Problems solved by technology

Document 2 "Extended Continuous Power Flow Calculation of Master-Slave Combined System Containing Distributed Power Generation" (Journal of Electrotechnical Society, 2012, Vol. In this method, both the transmission and distribution networks use orthogonal parameterization technology for continuous power flow calculation, so it is difficult to ensure the synchronization of the load growth of the transmission and distribution network during the continuous power flow calculation process, and it is also difficult to ensure that the P-V curve can be obtained reliably (the abscissa of the P-V curve represents "System active load variation", the ordinate indicates "system node voltage", the abscissa corresponding to the nose point of the P-V curve indicates "system power limit value", and the ordinate corresponding to the nose point indicates the nose point of "node voltage critical value") (that is, the critical point of voltage stability)

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