Second-order cone model for day-ahead dispatching of ac/dc active distribution networks

Abstract

The invention discloses a day-ahead dispatching second-order cone model of AC / DC active distribution network. The invention firstly establishes a steady-state power flow model of an AC distribution network, a DC distribution network and a voltage source converter, and establishes a steady-state power flow model of the AC / DC distribution network in the form of a second-order cone through a second-order cone relaxation technology. Furthermore, the model of active management measures for AC / DC active distribution network is established by modeling of active management measures. Finally, a mixed integer second-order cone model for day-ahead dispatching of AC / DC active distribution network is established. The objective function is to minimize the sum of the cost of power purchase and the penalty cost of light and wind abandonment, and the active power of active distribution network is realized through various active management measures and distribution network security constraints. Reactivepower joint optimization. The invention not only solves the problem that the line power flow exceeds the limit or the node voltage exceeds the limit due to the instability of the output of the distributed power source, but also solves the problem that how to carry out the day-ahead optimal dispatch after the high proportion distributed power source is connected into the AC / DC active distributionnetwork.

Description

technical field [0001] The invention belongs to the field of power grid dispatching automation, and relates to a second-order cone model for day-ahead dispatching of an AC / DC active distribution network considering joint optimization of active power and reactive power. Background technique [0002] Since the beginning of the 21st century, more and more serious environmental problems have prompted the energy policies of various countries to lean towards renewable energy. DC power sources such as DG and ESS (Energy Storage System) must be connected to the AC bus through a DC / AC inverter, requiring a large number of converters, which increases the operating loss of the system compared to connecting to the DC bus. The DC power supply connected to the AC distribution network through the inverter directly promotes the development of the DC distribution network. With the rapid development of DC loads and DC frequency conversion loads, users' demand for DC distribution networks is ...

AI Technical Summary

Problems solved by technology

[0003] The existing optimal scheduling model of AC and DC distribution network does not solve the efficiency and optimality of the model solution, and usually uses the Mixed Integer Nonlinear Programming model (Mixed Integer Nonlinear Programming, MINLP) for modeling, and the numerical value of the established model is The convergence of the solution is difficult to effectively guarantee; or the mixed integer linear programming model (Mixed Integer Linear Programming, MILP) is used for modeling, and the established model has been linearized, and the accuracy is low

In addition, some optimal scheduling models of AC and DC distribution networks do not consider the characteristics of large R / X ratio of AC distribution lines and strong coupling between active power and reactive power, and most of them do not consider the characteristics of active power and reactive power. power joint optimization

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