In artificial intelligence(AI)based-complex power system management and control technology,one of the urgent tasks is to evaluate AI intelligence and invent a way of autonomous intelligence evolution.However,there is,...In artificial intelligence(AI)based-complex power system management and control technology,one of the urgent tasks is to evaluate AI intelligence and invent a way of autonomous intelligence evolution.However,there is,currently,nearly no standard technical framework for objective and quantitative intelligence evaluation.In this article,based on a parallel system framework,a method is established to objectively and quantitatively assess the intelligence level of an AI agent for active power corrective control of modern power systems,by resorting to human intelligence evaluation theories.On this basis,this article puts forward an AI self-evolution method based on intelligence assessment through embedding a quantitative intelligence assessment method into automated reinforcement learning(AutoRL)systems.A parallel system based quantitative assessment and self-evolution(PLASE)system for power grid corrective control AI is thereby constructed,taking Bayesian Optimization as the measure of AI evolution to fulfill autonomous evolution of AI under guidance of their intelligence assessment results.Experiment results exemplified in the power grid corrective control AI agent show the PLASE system can reliably and quantitatively assess the intelligence level of the power grid corrective control agent,and it could promote evolution of the power grid corrective control agent under guidance of intelligence assessment results,effectively,as well as intuitively improving its intelligence level through selfevolution.展开更多
Power systems operate close to their voltage stability margin owing to the high load demand.To prevent voltage collapse,the system operator must be aware of the system functionality and be prepared to implement preven...Power systems operate close to their voltage stability margin owing to the high load demand.To prevent voltage collapse,the system operator must be aware of the system functionality and be prepared to implement preventive and corrective control measures.Hence,an appropriate algorithm to determine the time required by the operator is crucial,making it necessary to adopt appropriate models for effective implementation.Based on the load prediction curve for each bus,a new method is proposed to estimate the remaining time before voltage instability.Furthermore,an algorithm is developed to select the most suitable control action(preventive or corrective)based on the remaining time until the power system voltage instability occurs.In this study,two models based on voltage stability-constrained optimal power flow(VSC-OPF)are proposed,incorporating voltage stability index constraints for both control types.The effectiveness of the proposed algorithm and models is assessed using the IEEE 14-and 57-bus power systems,thereby demonstrating promising results.展开更多
With the advancements in voltage source converter(VSC)technology,VSC based high voltage direct current(VSCHVDC)systems provide system operators with a prospective approach to enhance system operating stability and res...With the advancements in voltage source converter(VSC)technology,VSC based high voltage direct current(VSCHVDC)systems provide system operators with a prospective approach to enhance system operating stability and resilience.In addition to long-distance transmission,the VSC-HVDC system can also provide multiple ancillary services,such as frequency regulation,due to its power controllability.However,if a time delay exists in the control signal,the VSC-HVDC system may bring destabilizing influences to the system,which will decrease the system resilience under the disturbance.In order to reduce control deviation caused by time delay,in this paper,a small signal model is first conducted to analyze the impact of time delay on system stability.Then a time-delay correction control strategy for HVDC frequency regulation control is developed to reduce the influence of the time delay.The control performance of the proposed time-delay correction control is verified both in the established small signal model and the runtime simulation in a modified IEEE 39 bus system.The results indicate that the proposed time-delay correction control strategy shows significant improvement in system stability.展开更多
With the development of power electronics-based units such as battery storage systems(BSS)and voltage source converters(VSC)that can quickly respond,the power system will receive a lot of security benefits from these ...With the development of power electronics-based units such as battery storage systems(BSS)and voltage source converters(VSC)that can quickly respond,the power system will receive a lot of security benefits from these fast control units.To fully utilize fast correction controls from the BSS and grid coupling VSC(GCVSC),this paper presents a new N-1 security-constrained stochastic unit commitment(SUC)model for hybrid AC and DC grids.In the proposed model,those fast-control units are used to avoid overloading and voltage violations in the post-contingency short-term period.In order to maintain good voltage profiles during pre-and post-contingency periods,the reactive power support ability of the BSS and the GCVSC is also considered.To improve calculation speed,the Bilinear Benders decomposition-based method is used to solve the proposed SUC model.Results on two examples,hybrid AC and DC grids,show that the proposed method can provide highly effective unit commitment solutions with post-contingency corrective actions,especially suitable for avoiding post-contingency short-term security problems in day-ahead dispatch.展开更多
Employing the novel Deep Reinforcement Learning approach,this paper addresses the active power corrective control in modern power systems.Seeking to minimize the joint effect engendered by operation cost and blackout ...Employing the novel Deep Reinforcement Learning approach,this paper addresses the active power corrective control in modern power systems.Seeking to minimize the joint effect engendered by operation cost and blackout penalty,this correction strategy focuses on evaluating the robustness and adaptability aspects of the control agent.In Part I of this paper,where robustness is the primary focus,the agent is developed to handle unexpected incidents and guide the stable operation of power grids A Simulation-driven Graph Attention Reinforcement Learning method is proposed to perform robust active power corrective control.The aim of the graph attention networks is to determine the representation of power system states considering the topological features.Monte Carlo tree search is adopted to select the best suitable action set out of the large action space,including generator redispatch and topology control actions.Finally,driven by simulation,a guided training mechanism along with a long-short-term action deployment strategy are designed to help the agent better evaluate the action set while training and to operate more stably when deployed.The efficacy of the proposed method has been demonstrated in the“2020 I earning to Run a Power Network.Neurips Track 1”global competition and the associated cases.Part II of this paper deals with the adaptability case,where the agent is equipped to better adapt to a grid that has an increasing share of renewable energies through the years.展开更多
Corrective control theory lays a novel foundation for the fault-tolerant control of asynchronous sequential machines. In this paper, we present a corrective control scheme for tolerating permanent state transition fau...Corrective control theory lays a novel foundation for the fault-tolerant control of asynchronous sequential machines. In this paper, we present a corrective control scheme for tolerating permanent state transition faults in the dynamics of asynchronous sequential machines. By a fault occurrence, the asynchronous machine may be stuck at a faulty state, not responding to the external input. We analyze the detectability of the considered faults and present the necessary and sufficient condition for the existence of a controller that overcomes any permanent transition faults. Fault tolerance is realized by using potential reachability and asynchronous mechanisms in the machine. A case study on an asynchronous counter is provided to illustrate the proposed fault detection and tolerance scheme.展开更多
基金supported by the National Key R&D Program of China[grant number 2018AAA0101504]。
文摘In artificial intelligence(AI)based-complex power system management and control technology,one of the urgent tasks is to evaluate AI intelligence and invent a way of autonomous intelligence evolution.However,there is,currently,nearly no standard technical framework for objective and quantitative intelligence evaluation.In this article,based on a parallel system framework,a method is established to objectively and quantitatively assess the intelligence level of an AI agent for active power corrective control of modern power systems,by resorting to human intelligence evaluation theories.On this basis,this article puts forward an AI self-evolution method based on intelligence assessment through embedding a quantitative intelligence assessment method into automated reinforcement learning(AutoRL)systems.A parallel system based quantitative assessment and self-evolution(PLASE)system for power grid corrective control AI is thereby constructed,taking Bayesian Optimization as the measure of AI evolution to fulfill autonomous evolution of AI under guidance of their intelligence assessment results.Experiment results exemplified in the power grid corrective control AI agent show the PLASE system can reliably and quantitatively assess the intelligence level of the power grid corrective control agent,and it could promote evolution of the power grid corrective control agent under guidance of intelligence assessment results,effectively,as well as intuitively improving its intelligence level through selfevolution.
文摘Power systems operate close to their voltage stability margin owing to the high load demand.To prevent voltage collapse,the system operator must be aware of the system functionality and be prepared to implement preventive and corrective control measures.Hence,an appropriate algorithm to determine the time required by the operator is crucial,making it necessary to adopt appropriate models for effective implementation.Based on the load prediction curve for each bus,a new method is proposed to estimate the remaining time before voltage instability.Furthermore,an algorithm is developed to select the most suitable control action(preventive or corrective)based on the remaining time until the power system voltage instability occurs.In this study,two models based on voltage stability-constrained optimal power flow(VSC-OPF)are proposed,incorporating voltage stability index constraints for both control types.The effectiveness of the proposed algorithm and models is assessed using the IEEE 14-and 57-bus power systems,thereby demonstrating promising results.
基金supported by National Natural Science Foundation of China(51977135,52207119).
文摘With the advancements in voltage source converter(VSC)technology,VSC based high voltage direct current(VSCHVDC)systems provide system operators with a prospective approach to enhance system operating stability and resilience.In addition to long-distance transmission,the VSC-HVDC system can also provide multiple ancillary services,such as frequency regulation,due to its power controllability.However,if a time delay exists in the control signal,the VSC-HVDC system may bring destabilizing influences to the system,which will decrease the system resilience under the disturbance.In order to reduce control deviation caused by time delay,in this paper,a small signal model is first conducted to analyze the impact of time delay on system stability.Then a time-delay correction control strategy for HVDC frequency regulation control is developed to reduce the influence of the time delay.The control performance of the proposed time-delay correction control is verified both in the established small signal model and the runtime simulation in a modified IEEE 39 bus system.The results indicate that the proposed time-delay correction control strategy shows significant improvement in system stability.
基金supported by National Natural Science Foundation of China under Grant 51707059.
文摘With the development of power electronics-based units such as battery storage systems(BSS)and voltage source converters(VSC)that can quickly respond,the power system will receive a lot of security benefits from these fast control units.To fully utilize fast correction controls from the BSS and grid coupling VSC(GCVSC),this paper presents a new N-1 security-constrained stochastic unit commitment(SUC)model for hybrid AC and DC grids.In the proposed model,those fast-control units are used to avoid overloading and voltage violations in the post-contingency short-term period.In order to maintain good voltage profiles during pre-and post-contingency periods,the reactive power support ability of the BSS and the GCVSC is also considered.To improve calculation speed,the Bilinear Benders decomposition-based method is used to solve the proposed SUC model.Results on two examples,hybrid AC and DC grids,show that the proposed method can provide highly effective unit commitment solutions with post-contingency corrective actions,especially suitable for avoiding post-contingency short-term security problems in day-ahead dispatch.
基金supported by the National Key R&D Program of China under Grant 2018AAA0101504the Science and technology project of SGCC(State Grid Corporation of China):fundamental theory of human-in-the-oop hybrid-augmented intelligence for power grid dispatch and control.
文摘Employing the novel Deep Reinforcement Learning approach,this paper addresses the active power corrective control in modern power systems.Seeking to minimize the joint effect engendered by operation cost and blackout penalty,this correction strategy focuses on evaluating the robustness and adaptability aspects of the control agent.In Part I of this paper,where robustness is the primary focus,the agent is developed to handle unexpected incidents and guide the stable operation of power grids A Simulation-driven Graph Attention Reinforcement Learning method is proposed to perform robust active power corrective control.The aim of the graph attention networks is to determine the representation of power system states considering the topological features.Monte Carlo tree search is adopted to select the best suitable action set out of the large action space,including generator redispatch and topology control actions.Finally,driven by simulation,a guided training mechanism along with a long-short-term action deployment strategy are designed to help the agent better evaluate the action set while training and to operate more stably when deployed.The efficacy of the proposed method has been demonstrated in the“2020 I earning to Run a Power Network.Neurips Track 1”global competition and the associated cases.Part II of this paper deals with the adaptability case,where the agent is equipped to better adapt to a grid that has an increasing share of renewable energies through the years.
文摘Corrective control theory lays a novel foundation for the fault-tolerant control of asynchronous sequential machines. In this paper, we present a corrective control scheme for tolerating permanent state transition faults in the dynamics of asynchronous sequential machines. By a fault occurrence, the asynchronous machine may be stuck at a faulty state, not responding to the external input. We analyze the detectability of the considered faults and present the necessary and sufficient condition for the existence of a controller that overcomes any permanent transition faults. Fault tolerance is realized by using potential reachability and asynchronous mechanisms in the machine. A case study on an asynchronous counter is provided to illustrate the proposed fault detection and tolerance scheme.
