Decision Method Of Proactive Operation For Distributed Generation Based On Power Quality Situation Awareness

The continuous depletion of conventional energy sources has led to the rapid development of DG technology for renewable energy sources such as wind energy and photovoltaic.And the grid-connected DG penetration is too high,it will affect the reliable and stable operation of the grid.At present,the research on power quality problems basically adopts the strategy of starting and managing,and can not guarantee the continuous and stable operation of microgrid.The emergence of microgrid grid-connected converters can realize the tracking compensation of power quality problems,which is a means to ensure the safe and stable operation of microgrid.This paper proposes to upgrade the grid-connected converter as an advanced converter with situational awareness and trend-oriented function,and to collect,understand and forecast all kinds of information elements involved in the change of power quality,and strive to grasp the change trend of factor information,through the change of the situation,and then guiding the micro-grid power quality control decision-making center in a right direction,which can achieve dynamic adjustment and control.In order to realize the awareness of power quality of the micro-grid system and the decision-making of the active operation of the micro-network converter,this paper studies the IEC 61850 90-7 standard,OpenADR communication specification,demand response technology,Markov decision process and micro-grid power flow calculation,decomposition and other related knowledge.Based on the demand response technology and the micro-grid power flow calculation,the knowledge of the change of the power quality of the micro-grid can be realized from different angles.The modeling method based on the Markov Decision Process is based on the idea of dynamic programming,The state of the process,the state transition probability matrix and the reward matrix to achieve the decision-making process modeling;the distributed system information modeling method based on IEC 61850 90-7standard can make the micro-grid system,the device has a self-description ability,to meet the interoperability between the various devices in the system.Based on the above technology,this paper proposes two kinds of distributed power generation active decision-making methods,which are based on grid price and micro-grid trend respectively.The former analyzes the demand status of the power quality of the microgrid by analyzing the power price of the grid,and realizing the perception of the demand state of the micro-grid power quality through the continuous power flow calculation and the singular value decomposition method.The optimal decision of the distributed operation mode of the distributed generation converter is obtained through the MarkovDecision Process model,and the latter is a two-stage distributed active power generation decision.The first stage is based on the singular value decomposition method.The second stage is based on the information of the power quality demand predicted by the micro-network tidal current prediction,and the converter is based on the Markov Decision-making process.