Research On The Optimal Power Flow Of VSC-MTDC And Hybrid System

With the development of wind energy and solar energy in the last few decades, it has been expanding worldwide. However, the development of wind energy and solar energy has its limitations, such as the volatility, intermittent, resulting in power quality and output power can not meet the requirements of direct grid. In the implementation of wind energy grid, the most important step in the first rectifier and then the inverter link. In the implementation of solar energy and network, the most important step in the first step-up and then reverse the link. So the new energy and the first step is based on the inverter DC part. In the selection of location, large-scale distribution of new energy power generation location requirements need to stay away from the load center, submarine cable transmission is essential for offshore wind farm, because of these factors using multi-terminal DC transmission in the majority of the competition more practical value, The optimal power flow method in theory and practice have a pivotal position, and this method is multi-terminal DC and AC hybrid system important method.In this paper, DC system of voltage source converter is selected as the research object. The purpose of this paper is to analyze the principle of the basic power flow equation, comb the regulation method and study its AC side regulation. Under the condition of ensuring the stable operation of the system, the variable regions of DC voltage, current and pulse width modulation wave angle are further generalized.This paper introduces the optimal power flow model, which is based on the VSC multi-terminal DC and AC hybrid system. The core of this model is to minimize the cost of power generation under the conditions of the power flow of the hybrid system and the stable operation of the system. At the same time, the model can not ignore the connection transformer and the internal loss of the converter, the actual situation that VSC multi-terminal DC and AC hybrid system.The interior-point algorithm of the optimal power flow is based on the VSC multi-terminal DC / AC hybrid system. According to the calculation method of interior point method, the formula of optimal tide is analyzed, and the interior point algorithm of optimal power flow is obtained.The corresponding preparation of debugging the corresponding simulation program. The IEEE-14 nodes are selected to obtain the optimal power flow solution. From the cost point of view, the optimal power flow method compared with the ordinary power flow method, the choice of the optimal power flow of the hybrid system to run the economic level can teach to improve the overall system to run the purpose.In this paper, the VSC converter characteristics are fully considered in the model, and the system can be run stably, and the mathematical model can be obtained which can truly reflect the actual situation of VSC multi-terminal DC and AC hybrid system. From the practical significance level, the optimal power flow method of the VSC multi-terminal DC and AC hybrid system has important significance in the economic point of view and the overall energy efficiency point of view.