Automatic Voltage Control Method Based On Linear Sensitivity Analysis And Its Software Development

At present, the major electrical network of China still uses the traditionaldisperser adjustment way to control voltage and reactive power. This control methodcan’t comprehensively considerate and coordinate the whole network which consist ofall station system. For this reason, it can only realize local optimization and isdifficult to realize the purpose of the optimization which is to improve the nodevoltage and reduce the line loss from the full-scale view in the whole network. Takingautomatic voltage control project of Hunan power grid as an example, this dissertationattempts to implement study on effective reactive power optimization of the wholesystem．The thesis analyzes the significance of reactive voltage optimization control andintroduces the basic mathematical model and development status of reactive voltagecontrol. In addition, reactive voltage control optimization algorithms that are appliedto the power system are reviewed and its characteristics and applications areanalyzed.By bringing the application of current automatic voltage control method in realsystem into consideration and reviewing speed and precision requirements forreal-time analysis, this thesis proposes a method of automatic voltage control that isbased on linear sensitivity analysis. It doesn’t consider step-down transformer.Regional voltage effective constraint node concept is presented based on thecomprehensive understanding of the operation of voltage and reactive power control.The node voltage constraint in the linear programming model consists of only thedominated high voltage and low voltage nodes, therefore the voltage constraintdimension can be effectively reduced and the speed of linear programming can besignificantly improved. Further more, the sensitivity of balancing machineinformation is obtained, which can participate in voltage and reactive power control.When added balancing machine to the control, without prejudice to the accuracy andspeed of the calculation, the system network loss is effectively reduced.Based on automatic voltage control algorithm which is mentioned in the previousparagraph, a software of AVC is designed based on web. This software in the serversystem is exploited by C++and Java programme language. This paper introduces thetechnical processes during the period of software development and functions of all modules and software user interface with IEEE-10, IEEE-14and IEEE-30system andthe real EMS data of Hunan Electric Power System added in the research. Finally, thesystem network loss is significantly reduced and the voltage qualification rate isgreatly improved, proving the correctness and accurateness of this approach.