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Voltage Control For Active Distribution Nestworks Based On Model Predictive Control

Posted on:2018-12-29Degree:MasterType:Thesis
Country:ChinaCandidate:J M ZhangFull Text:PDF
GTID:2322330542451976Subject:Electrical engineering
Abstract/Summary:PDF Full Text Request
Active distribution network(ADN)contains many distributed generators(DGs).Since the intermittent characteristic of some kind of DGs,such as photovoltaic(PV)and wind turbine(WT),DGs have significant influence on the power loss,voltage,power quality and stability of ADN and the ADN operation control is facing great challenges.With the development of power electronics technology,DSs are more and more controllable,which provides new control method for ADN voltage control at the same time.In this paper,the main objective is proposing a new voltage control strategy in which DGs can participate.The main content of this paper can be listed as follows:1.The research background and the state-of-art of the voltage control method in ADN are introduced,and the characteristics of three kinds of voltage control modes are explained.In addition,the model predictive control and its application in ADN are introduced.2.The concept and characteristics of multi-area ADN are expounded in detail,and the rationality of using distributed control method in multi-area ADN is described.Then,the characteristics and models of voltage regulating equipment available in AND are introduced.Futhermore,the principle,steps and characteristics of model predictive control are introduced.On this basis,the distributed model predictive control(DMPC)method is described.3.Based on the characteristics of multi-area ADN in non-electric power market environment,an improved DMPC voltage cooperative control strategy is proposed,which includes:(1)The voltage deviation of the adjacent area is added to the objective function of the area controller.Hence,the voltage control effect of the overall ADN can be improved at the cost of the lightly increase of exchanged information amout among areas.(2)Aiming at the different speed of different voltage regulation equipment in ADN,the action delay variable is added to the prediction model to realize the coordination of different speed regulation equipment.(3)The fixed constraints of the state variables are softened into a gradient constraint to reduce the adjustment process oscillation.4.Based on the characteristics of multi-area ADN in electric power market environment,a two-stage distributed voltage cooperative control strategy is proposed,and the area external model is extablished.In the first stage,a pre-evaluation strategy is proposed to allocate the voltage regulation task among adjacent areas according to the area external model.In the second stage,a DMPC strategy which takes the interests of different areas into account is proposed,which can realize the control objectives of multiple areas at the same time,while preserving the fast reserve capacity of the area as much as possible.
Keywords/Search Tags:active distribution network, model predictive control, voltage control, distributed control
PDF Full Text Request
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