Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption o...Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption of wind generators.In this study,a two-stage reactive power optimization method based on the alternating direction method of multipliers(ADMM)algorithm is proposed for achieving optimal reactive power dispatch in wind farm-integrated distribution systems.Unlike existing optimal reactive power control methods,the proposed method enables distributed reactive power flow optimization with a two-stage optimization structure.Furthermore,under the partition concept,the consensus protocol is not needed to solve the optimization problems.In this method,the influence of the wake effect of each wind turbine is also considered in the control design.Simulation results for a mid-voltage distribution system based on MATLAB verified the effectiveness of the proposed method.展开更多
A distributed active and reactive power control(DARPC)strategy based on the alternating direction method of multipliers(ADMM)is proposed for regional AC transmission system(TS)with wind farms(WFs).The proposed DARPC s...A distributed active and reactive power control(DARPC)strategy based on the alternating direction method of multipliers(ADMM)is proposed for regional AC transmission system(TS)with wind farms(WFs).The proposed DARPC strategy optimizes the power distribution among the WFs to minimize the power losses of the AC TS while tracking the active power reference from the transmission system operator(TSO),and minimizes the voltage deviation of the buses inside the WF from the rated voltage as well as the power losses of the WF collection system.The optimal power flow(OPF)of the TS is relaxed by using the semidefinite programming(SDP)relaxation while the branch flow model is used to model the WF collection system.In the DARPC strategy,the large-scale strongly-coupled optimization problem is decomposed by using the ADMM,which is solved in the regional TS controller and WF controllers in parallel without loss of the global optimality.The boundary information is exchanged between the regional TS controller and WF controllers.Compared with the conventional OPF method of the TS with WFs,the optimality and accuracy of the system operation can be improved.Moreover,the proposed strategy efficiently reduces the computation burden of the TS controller and eliminates the need of a central controller.The protection of the information privacy can be enhanced.A modified IEEE 9-bus system with two WFs consisting of 64 wind turbines(WTs)is used to validate the proposed DARPC strategy.展开更多
针对目前谐波电流造成特定线路各元件损耗难以明确其来源的问题,提出一种基于无功功率方向法来判别引起公共连接点(point of common coupling,PCC)处的主谐波电流来源方法。通常情况下,系统侧和用户侧谐波源流过特定线路各元件造成的损...针对目前谐波电流造成特定线路各元件损耗难以明确其来源的问题,提出一种基于无功功率方向法来判别引起公共连接点(point of common coupling,PCC)处的主谐波电流来源方法。通常情况下,系统侧和用户侧谐波源流过特定线路各元件造成的损耗大小,可由两侧各自贡献的谐波电流大小区分,故以谐波电流指标为判别依据。以电网中谐波阻抗基本性质为基础,结合PCC处谐波电压和电流实测信息,利用基本电路原理和不等式约束条件,在谐波无功功率方向法的思路与判别条件下,推导得出了仅根据谐波电压和电流的相角差,就可直接判别主谐波电流来源的方法。最后,通过多种实际工程场景的实测数据,验证了该方法的有效性,使用中的便捷性反映了该方法在工程实用中的价值。展开更多
基金support of The National Key Research and Development Program of China(Basic Research Class)(No.2017YFB0903000)the National Natural Science Foundation of China(No.U1909201)。
文摘Since the connection of small-scale wind farms to distribution networks,power grid voltage stability has been reduced with increasing wind penetration in recent years,owing to the variable reactive power consumption of wind generators.In this study,a two-stage reactive power optimization method based on the alternating direction method of multipliers(ADMM)algorithm is proposed for achieving optimal reactive power dispatch in wind farm-integrated distribution systems.Unlike existing optimal reactive power control methods,the proposed method enables distributed reactive power flow optimization with a two-stage optimization structure.Furthermore,under the partition concept,the consensus protocol is not needed to solve the optimization problems.In this method,the influence of the wake effect of each wind turbine is also considered in the control design.Simulation results for a mid-voltage distribution system based on MATLAB verified the effectiveness of the proposed method.
基金supported in part by Technical University of Denmark(DTU)in part by China Scholarship Council(No.201806130202)。
文摘A distributed active and reactive power control(DARPC)strategy based on the alternating direction method of multipliers(ADMM)is proposed for regional AC transmission system(TS)with wind farms(WFs).The proposed DARPC strategy optimizes the power distribution among the WFs to minimize the power losses of the AC TS while tracking the active power reference from the transmission system operator(TSO),and minimizes the voltage deviation of the buses inside the WF from the rated voltage as well as the power losses of the WF collection system.The optimal power flow(OPF)of the TS is relaxed by using the semidefinite programming(SDP)relaxation while the branch flow model is used to model the WF collection system.In the DARPC strategy,the large-scale strongly-coupled optimization problem is decomposed by using the ADMM,which is solved in the regional TS controller and WF controllers in parallel without loss of the global optimality.The boundary information is exchanged between the regional TS controller and WF controllers.Compared with the conventional OPF method of the TS with WFs,the optimality and accuracy of the system operation can be improved.Moreover,the proposed strategy efficiently reduces the computation burden of the TS controller and eliminates the need of a central controller.The protection of the information privacy can be enhanced.A modified IEEE 9-bus system with two WFs consisting of 64 wind turbines(WTs)is used to validate the proposed DARPC strategy.
文摘针对目前谐波电流造成特定线路各元件损耗难以明确其来源的问题,提出一种基于无功功率方向法来判别引起公共连接点(point of common coupling,PCC)处的主谐波电流来源方法。通常情况下,系统侧和用户侧谐波源流过特定线路各元件造成的损耗大小,可由两侧各自贡献的谐波电流大小区分,故以谐波电流指标为判别依据。以电网中谐波阻抗基本性质为基础,结合PCC处谐波电压和电流实测信息,利用基本电路原理和不等式约束条件,在谐波无功功率方向法的思路与判别条件下,推导得出了仅根据谐波电压和电流的相角差,就可直接判别主谐波电流来源的方法。最后,通过多种实际工程场景的实测数据,验证了该方法的有效性,使用中的便捷性反映了该方法在工程实用中的价值。
