The Research On Coordinated Control Of Multi-FACTS Devices For Improving The Power Flow Distribution

The appearance of FACTS technology provides a new approach to power flowcontrol of modern power system. Thus, the issue that how to improve the power flowdistribution by applying the new FACTS technology has been one of the main directionof the study of the FACTS technology. However, the inter-actions betweenmulti-FACTS devices, which exist in the same system, brings bad effect to some extentto the effectiveness of the power flow control with FACTS technology. Therefore, it’snecessary to start the study of the issue that coordinated control to improve the powerdistribution of the system.The coordinated power flow control and the OPF under the circumstance ofenergy market with FACTS are analyzed and researched specifically with theconsideration of inter-action between multi-FACTS devices.The issue of coordinated power flow control is handled as nonlinear-constrainedproblem when considering the FACTS control targets. The coordinated power flowcontrol model is established and the sensitity coefficient of the objective function withrespect to the FACTS cntrol parameters is calculated. Then, based on Interior-pointalgorithm the coordinated power flow control model is solved. Case study shows theeffectiveness of the proposed model in dealing with the coordination of themulti-objects of FACTS devices.The OPF in energy market with the consideration of the inter-action betweenmulti-FACTS devices (OPF-FACTS) tends to achieve the minimum generation cost onthe premise of the FACTS devices coordinate with each other. In this paper, theOPF-FACTS is classified into two categories. One is that the objective of the OPFmodel is just to achieve the minimum generation cost. And the other is that theobjective of the OPF model includes the minimum generation cost and meanwhile thegood performance of every FACTS device in their control targets. The solution of howto consider the control objectives of the multi-FACTS devices is discussed. Case studyshows that the latter one cost more than the former one.Based on the exsiting research results, the OPF-TSC model consideringmulti-FACTS devices is established and then solved by applying the Interior-pointalgorithm. Case study shows that adding additional stability constraints such astransient stability constraint, the generation cost and the branch loss of OPF-FACTSwill increase definitely for additional power generation is needed to achieve the constraints, and thus lead to more active and reactive power transmitted on thebranches.This paper has studied the power flow control and optimal power flow of thepower systems in which multi-FACTS devices installed with the consideration of theinteractions between multi-FACTS devices. The work done in the paper can providereferences to the follow-up study of the power flow improvement with multi-FACTSdevices.