Distributed photovoltaic (PV) entities can be coordinated to provide reactive power for voltage regulation in distribution networks.However,integrating large-scale distributed PV entities into reactive power optimizat...Distributed photovoltaic (PV) entities can be coordinated to provide reactive power for voltage regulation in distribution networks.However,integrating large-scale distributed PV entities into reactive power optimization makes it difficult to balance the individual benefit of each PV entity with the overall economic efficiency of the system.To address this challenge,we propose a market-oriented two-stage reactive power regulation method.At the first stage,a long-term multi-layer reactive power capacity market is created to incentivize each PV entity to provide reactive power capacity,while ensuring their financial interests are guaranteed.At the second stage,a real-time multi-layer reactive power dispatch mechanism is introduced to manage the reactive power generation of distributed PV entities,prioritizing the dispatch of lower-cost PV entities to maximize system-wide economic efficiency.Simulation results based on a real Finnish radial distribution network demonstrate the effectiveness of the proposed method in optimizing reactive power for large-scale distributed PV entities.展开更多
A synchronous condenser(SC)isusedto maintain grid voltage stability owing to its bidirectional fast reactive power regulation ability and good dynamic characteristics.To address the issue of dynamic voltage instabilit...A synchronous condenser(SC)isusedto maintain grid voltage stability owing to its bidirectional fast reactive power regulation ability and good dynamic characteristics.To address the issue of dynamic voltage instability inpower systemduring failuresor heavy inductive loads,an SC reactive power regulation optimization method based onsingle neuron adaptive PID(SNA-PID)combined with whale optimization algorithm(WOA)is proposed.This approach aimsto overcome the limitationsof normal PID controllers.Asimulation model of the SC reactive power regulation system,based on SNA-PID combined with the WOA,is established using Matlab.The parameters of the SNA-PID are optimizedbythe WOAwith the ITAE criterion under two typical operation situationsof the power system:one is to set three different degrees of short-circuit ground faults,and the other isto accessthree different three-phase resistive loads.Compared to conventional PID control,asthe degree of short-circuit ground faults increases and the three-phase resistive load resistance decreases,the SC reactive power regulation optimization method based on SNA-PID combined with the WOA can still reduce the voltage recovery time and voltage oscillation,while maintaining voltage stability.Simulation results show that the proposed method exhibits better dynamic adjustment characteristics and adaptive ability.展开更多
Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering ...Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering largescale wind-power transmission.First,the unique voltage characteristics of half-wavelength lines are deduced based on the distributed parameter model.In the secondary voltage-control level,reactive power-transmission limits of half-wavelength lines are introduced as another control objective except for tracing the pilot bus voltage reference.Considering the uncertainty and fluctuation of wind power,the overvoltage risk-assessment method of half-wavelength lines is presented to determine specific voltage-control strategies.Simulation results demonstrate that the proposed voltage-control method delivers superior tracking performance according to a voltage reference value and prevents the overvoltage risk of halfwavelength lines effectively in different wind-power penetrations.展开更多
The penetration rate of distributed generation is gradually increasing in the distribution system concerned.This is creating new problems and challenges in the planning and operation of the system.The intermittency an...The penetration rate of distributed generation is gradually increasing in the distribution system concerned.This is creating new problems and challenges in the planning and operation of the system.The intermittency and variability of power outputs from numerous distributed renewable generators could significantly jeopardize the secure operation of the distribution system.Therefore,it is necessary to assess the hosting capability for intermittent distributed generation by a distribution system considering operational constraints.This is the subject of this study.An assessment model considering the uncertainty of generation outputs from distributed generators is presented for this purpose.It involves different types of regulation or control functions using on-load tap-changers(OLTCs),reactive power compensation devices,energy storage systems,and the reactive power support of the distributed generators employed.A robust optimization model is then attained It is solved by Bertsimas robust counterpart through GUROBI solver.Finally,the feasibility and efficiency of the proposed method are demonstrated by a modified IEEE 33-bus distribution system.In addition,the effects of the aforementioned regulation or control functions on the enhancement of the hosting capability for intermittent distributed generation are examined.展开更多
基金supported by Natural Science Foundation of Henan(No.252300421523)National Natural Science Foundation of China(No.52422705)Foundation of Key Laboratory of Cleaner Intelligent Control on Coal&Electricity,Ministry of Education,China(No.CICCE202409).
文摘Distributed photovoltaic (PV) entities can be coordinated to provide reactive power for voltage regulation in distribution networks.However,integrating large-scale distributed PV entities into reactive power optimization makes it difficult to balance the individual benefit of each PV entity with the overall economic efficiency of the system.To address this challenge,we propose a market-oriented two-stage reactive power regulation method.At the first stage,a long-term multi-layer reactive power capacity market is created to incentivize each PV entity to provide reactive power capacity,while ensuring their financial interests are guaranteed.At the second stage,a real-time multi-layer reactive power dispatch mechanism is introduced to manage the reactive power generation of distributed PV entities,prioritizing the dispatch of lower-cost PV entities to maximize system-wide economic efficiency.Simulation results based on a real Finnish radial distribution network demonstrate the effectiveness of the proposed method in optimizing reactive power for large-scale distributed PV entities.
基金Supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX21_0474).
文摘A synchronous condenser(SC)isusedto maintain grid voltage stability owing to its bidirectional fast reactive power regulation ability and good dynamic characteristics.To address the issue of dynamic voltage instability inpower systemduring failuresor heavy inductive loads,an SC reactive power regulation optimization method based onsingle neuron adaptive PID(SNA-PID)combined with whale optimization algorithm(WOA)is proposed.This approach aimsto overcome the limitationsof normal PID controllers.Asimulation model of the SC reactive power regulation system,based on SNA-PID combined with the WOA,is established using Matlab.The parameters of the SNA-PID are optimizedbythe WOAwith the ITAE criterion under two typical operation situationsof the power system:one is to set three different degrees of short-circuit ground faults,and the other isto accessthree different three-phase resistive loads.Compared to conventional PID control,asthe degree of short-circuit ground faults increases and the three-phase resistive load resistance decreases,the SC reactive power regulation optimization method based on SNA-PID combined with the WOA can still reduce the voltage recovery time and voltage oscillation,while maintaining voltage stability.Simulation results show that the proposed method exhibits better dynamic adjustment characteristics and adaptive ability.
基金supported by State Grid Corporation of China,Projects under Grant 520626200031National Natural Science Foundation of China,No.51877200。
文摘Half-wavelength transmission can transmit large-scale renewable energy over very long distances.This paper proposes an improved steady-state voltage-control method for half-wavelength transmission systems considering largescale wind-power transmission.First,the unique voltage characteristics of half-wavelength lines are deduced based on the distributed parameter model.In the secondary voltage-control level,reactive power-transmission limits of half-wavelength lines are introduced as another control objective except for tracing the pilot bus voltage reference.Considering the uncertainty and fluctuation of wind power,the overvoltage risk-assessment method of half-wavelength lines is presented to determine specific voltage-control strategies.Simulation results demonstrate that the proposed voltage-control method delivers superior tracking performance according to a voltage reference value and prevents the overvoltage risk of halfwavelength lines effectively in different wind-power penetrations.
基金the Scientific and Technological Project of SGCC Headquarters entitled“Smart Distribution Network and Ubiquitous Power Internet of Things Integrated Development Collaborative Planning Technology Research”(5400-201956447A-0-0-00).
文摘The penetration rate of distributed generation is gradually increasing in the distribution system concerned.This is creating new problems and challenges in the planning and operation of the system.The intermittency and variability of power outputs from numerous distributed renewable generators could significantly jeopardize the secure operation of the distribution system.Therefore,it is necessary to assess the hosting capability for intermittent distributed generation by a distribution system considering operational constraints.This is the subject of this study.An assessment model considering the uncertainty of generation outputs from distributed generators is presented for this purpose.It involves different types of regulation or control functions using on-load tap-changers(OLTCs),reactive power compensation devices,energy storage systems,and the reactive power support of the distributed generators employed.A robust optimization model is then attained It is solved by Bertsimas robust counterpart through GUROBI solver.Finally,the feasibility and efficiency of the proposed method are demonstrated by a modified IEEE 33-bus distribution system.In addition,the effects of the aforementioned regulation or control functions on the enhancement of the hosting capability for intermittent distributed generation are examined.
