With the development of power systems, power grid within a control area becomes much more complicated due to increasing number of nodes and renewable energy interconnections. The role of power system control center is...With the development of power systems, power grid within a control area becomes much more complicated due to increasing number of nodes and renewable energy interconnections. The role of power system control center is more critical in maintaining system reliable and security operations. Latest developed information and communication technologies provide a platform to enhance the functions and performance of power system control center. Smart power dispatch concept will be the trend of future control center development. In this paper, we start from the human factors of control center design and propose operation indices to reduce the information presented to the system operator. The operation indices will be the important criteria in situation awareness of a power grid. Past, present, future and capability states of a power grid are also proposed to provide better visions to the operator of system conditions. The basic ideas of operation indices and operation states are discussed in the paper. In the end, the design factors for a power dispatch cockpit are discussed.展开更多
The convergence of Internet of Things(IoT),5G,and cloud collaboration offers tailored solutions to the rigorous demands of multi-flow integrated energy aggregation dispatch data processing.While generative adversarial...The convergence of Internet of Things(IoT),5G,and cloud collaboration offers tailored solutions to the rigorous demands of multi-flow integrated energy aggregation dispatch data processing.While generative adversarial networks(GANs)are instrumental in resource scheduling,their application in this domain is impeded by challenges such as convergence speed,inferior optimality searching capability,and the inability to learn from failed decision making feedbacks.Therefore,a cloud-edge collaborative federated GAN-based communication and computing resource scheduling algorithm with long-term constraint violation sensitiveness is proposed to address these challenges.The proposed algorithm facilitates real-time,energy-efficient data processing by optimizing transmission power control,data migration,and computing resource allocation.It employs federated learning for global parameter aggregation to enhance GAN parameter updating and dynamically adjusts GAN learning rates and global aggregation weights based on energy consumption constraint violations.Simulation results indicate that the proposed algorithm effectively reduces data processing latency,energy consumption,and convergence time.展开更多
The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-domin...The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-dominated grids.Conventional classifica-tions,which decouple voltage,frequency,and rotor angle stability,fail to address the emerging strong voltage‒angle coupling effects caused by RES dynamics.This coupling introduces complex oscillation modes and undermines system robustness,neces-sitating novel stability assessment tools.Recent studies focus on eigenvalue distributions and damping redistribution but lack quantitative criteria and interpretative clarity for coupled stability.This work proposes a transient energy-based framework to resolve these gaps.By decomposing transient energy into subsystem-dissipated components and coupling-induced energy exchange,the method establishes stability criteria compatible with a broad variety of inverter-interfaced devices while offering an intuitive energy-based interpretation for engineers.The coupling strength is also quantified by defining the relative coupling strength index,which is directly related to the transient energy interpretation of the coupled stability.Angle‒voltage coupling may induce instability by injecting transient energy into the system,even if the individual phase angle and voltage dynamics themselves are stable.The main contributions include a systematic stability evaluation framework and an energy decomposition approach that bridges theoretical analysis with practical applicability,addressing the urgent need for tools for managing modern power system evolving stability challenges.展开更多
To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrate...To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrated grid-following control mode,allowing smooth switching between GFL and GFM modes.First,impedance models of GFL and GFM PV energy storage VSG systems were established,and grid stability was analyzed.Second,an online impedance identification method based on voltage fluctuation data screening was proposed to enhance the accuracy of impedance identification.Additionally,a PV energy storage GFM/GFL VSG smooth switching method based on current inner loop compensation was introduced to achieve stable grid-connected operation of distributed photovoltaics under changes in strong and weak power grids.Finally,a grid stability analysis was conducted on the multi-machine parallel PV ESS,and a simulation model of a multi-machine parallel PV ESS based on current inner loop compensation was established for testing.Results showed that,compared to using a single GFM or single GFL control for the PV VSG system,the smooth switching method of multi-machine parallel PV ESS effectively suppresses system resonance under variations in power grid strength,enabling adaptive and stable grid-connected operations of distributed PV.展开更多
A decision feedback equalization(DFE)algorithm is proposed by simplifying Volterra structure.The simplification principle and process of the proposed Volterra-based equalization algorithm are presented.With the suppor...A decision feedback equalization(DFE)algorithm is proposed by simplifying Volterra structure.The simplification principle and process of the proposed Volterra-based equalization algorithm are presented.With the support of this algorithm,the signal damage for four-level pulse amplitude modulation signal(PAM-4)is compensated,which is caused by device bandwidth limitation and dispersion during transmission in C-band intensity modulation direct detection(IM-DD)fiber system.Experiments have been carried out to demonstrate that PAM-4 signals can transmit over 2 km in standard single-mode fiber(SSMF)based on a 30 GHz Mach-Zehnder modulator(MZM).The bit error rate(BER)can reach the threshold of hard decision-forward error correction(HD-FEC)(BER=3.8×10-3)and its sensitivity is reduced by 2 d Bm compared with traditional feedforward equalization(FFE).Meanwhile,the algorithm complexity is greatly reduced by 55%,which provides an effective theoretical support for the commercial application of the algorithm.展开更多
With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite comm...With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite communication provides a large coverage area suitable for a variety of services and is less affected by geographical factors;moreover,the costs are independent of the communication distance.This study investigates information acquisition technology for small hydropower stations in remote areas using high-and low-orbit satellites.The information collection needs of small hydropower stations in remote areas are analyzed,and an information acquisition system is designed using high-and low-orbit satellites.For network security protection,network anomaly detection technology based on a support vector machine algorithm is proposed.The effectiveness of information collection was evaluated and verified for small hydropower plants in remote areas.The system provides technical support for“full coverage,full collection,and full monitoring”of the measurement automation information acquisition system.展开更多
By using electric power data,observational station temperature data in Beijing,CN05.1 temperature data,ERA5 atmospheric reanalysis data,and ERSST.v3 b sea surface temperature(SST) data,it is found that summer(JulyAugu...By using electric power data,observational station temperature data in Beijing,CN05.1 temperature data,ERA5 atmospheric reanalysis data,and ERSST.v3 b sea surface temperature(SST) data,it is found that summer(JulyAugust) electric power demand in Beijing is remarkably positively correlated with the previous spring(MarchApril) tropical North Atlantic(TNA) SST anomaly(SSTA).The possible physical mechanism of the TNA SSTA affecting summer electric power in Beijing is also revealed.When a positive SSTA occurs in the TNA during spring,anomalous easterlies prevail over the tropical central Pacific,which can persist to the following summer.Trade winds are thus enhanced over the northern Pacific,which favors a strengthening of upwelling cold water in the tropical central-eastern Pacific.As a result,a negative SSTA appears in the central-eastern Pacific in summer,which means a La Nina event is triggered by the previous TNA SSTA through the Bjerknes feedback.During the La Nina event,an anomalous anticyclonic circulation occupies the northwestern Pacific.The southerly anomalies at the western edge of this anomalous anticyclone strengthen the transportation of warm and humid airflow from the low latitudes to North China,where Beijing is located,causing higher summer temperatures and increased electricity usage for air conditioning,and vice versa.The results of this study might provide a new scientific basis and dues for the seasonal prediction of summer electric power demand in Beijing.展开更多
Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system canno...Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system cannot quantitatively estimate the actual operating conditions of the power system for only considering the most serious and credible accidents.Therefore,the risk theory is introduced into an on-line security assessment system and then an on-line risk assessment system for wind power is designed and implemented by combining with the dynamic security assessment system.Based on multiple data integration,the wind power disturbance probability is available and the security assessment of the power grid can obtain security indices in different aspects.The operating risk index is an expectation of severity,computed by summing up all the products of the result probability and its severity.Analysis results are reported to the dispatchers in on-line environment,while the comprehensive weak links are automatically provided to the power dispatching center.The risk assessment system in operation can verify the reasonableness of the system.展开更多
The variability characteristics of Guangdong daily power load from 2002 to 2004 and its connection to meteorological variables are analyzed with wavelet analysis and correlation analysis. Prediction equations are esta...The variability characteristics of Guangdong daily power load from 2002 to 2004 and its connection to meteorological variables are analyzed with wavelet analysis and correlation analysis. Prediction equations are established using optimization subset regression. The results show that a linear increasing trend is very significant and seasonal change is obvious. The power load exhibits significant quasi-weekly (5 – 7 days) oscillation, quasi-by-weekly (10 – 20 days) oscillation and intraseasonal (30 – 60 days) oscillation. These oscillations are caused by atmospheric low frequency oscillation and public holidays. The variation of Guangdong daily power load is obviously in decrease on Sundays, shaping like a funnel during Chinese New Year in particular. The minimum is found at the first and second day and the power load gradually increases to normal level after the third day during the long vacation of Labor Day and National Day. Guangdong power load is the most sensitive to temperature, which is the main affecting factor, as in other areas in China. The power load also has relationship with other meteorological elements to some extent during different seasons. The maximum of power load in summer, minimum during Chinese New Year and variation during Labor Day and National Day are well fitted and predicted using the equation established by optimization subset regression and accounting for the effect of workdays and holidays.展开更多
文摘With the development of power systems, power grid within a control area becomes much more complicated due to increasing number of nodes and renewable energy interconnections. The role of power system control center is more critical in maintaining system reliable and security operations. Latest developed information and communication technologies provide a platform to enhance the functions and performance of power system control center. Smart power dispatch concept will be the trend of future control center development. In this paper, we start from the human factors of control center design and propose operation indices to reduce the information presented to the system operator. The operation indices will be the important criteria in situation awareness of a power grid. Past, present, future and capability states of a power grid are also proposed to provide better visions to the operator of system conditions. The basic ideas of operation indices and operation states are discussed in the paper. In the end, the design factors for a power dispatch cockpit are discussed.
基金supported by China Southern Power Grid Technology Project under Grant 03600KK52220019(GDKJXM20220253).
文摘The convergence of Internet of Things(IoT),5G,and cloud collaboration offers tailored solutions to the rigorous demands of multi-flow integrated energy aggregation dispatch data processing.While generative adversarial networks(GANs)are instrumental in resource scheduling,their application in this domain is impeded by challenges such as convergence speed,inferior optimality searching capability,and the inability to learn from failed decision making feedbacks.Therefore,a cloud-edge collaborative federated GAN-based communication and computing resource scheduling algorithm with long-term constraint violation sensitiveness is proposed to address these challenges.The proposed algorithm facilitates real-time,energy-efficient data processing by optimizing transmission power control,data migration,and computing resource allocation.It employs federated learning for global parameter aggregation to enhance GAN parameter updating and dynamically adjusts GAN learning rates and global aggregation weights based on energy consumption constraint violations.Simulation results indicate that the proposed algorithm effectively reduces data processing latency,energy consumption,and convergence time.
基金supported by the Science and Technology Project of China Southern Power Grid Co.,Ltd under Grant 036000KC23090004(GDKJXM20231026).
文摘The integration of renewable energy sources(RESs)with inverter interfaces has fundamentally reshaped power system dynamics,challenging traditional stability analysis frameworks designed for synchronous generator-dominated grids.Conventional classifica-tions,which decouple voltage,frequency,and rotor angle stability,fail to address the emerging strong voltage‒angle coupling effects caused by RES dynamics.This coupling introduces complex oscillation modes and undermines system robustness,neces-sitating novel stability assessment tools.Recent studies focus on eigenvalue distributions and damping redistribution but lack quantitative criteria and interpretative clarity for coupled stability.This work proposes a transient energy-based framework to resolve these gaps.By decomposing transient energy into subsystem-dissipated components and coupling-induced energy exchange,the method establishes stability criteria compatible with a broad variety of inverter-interfaced devices while offering an intuitive energy-based interpretation for engineers.The coupling strength is also quantified by defining the relative coupling strength index,which is directly related to the transient energy interpretation of the coupled stability.Angle‒voltage coupling may induce instability by injecting transient energy into the system,even if the individual phase angle and voltage dynamics themselves are stable.The main contributions include a systematic stability evaluation framework and an energy decomposition approach that bridges theoretical analysis with practical applicability,addressing the urgent need for tools for managing modern power system evolving stability challenges.
基金supported by National Key Research and Development Technology Project program(SQ2022YFB2400136).
文摘To enable distributed PV to adapt to variations in power grid strength and achieve stable grid connection while enhancing operational flexibility,it is essential to configure grid-connected inverters with an integrated grid-following control mode,allowing smooth switching between GFL and GFM modes.First,impedance models of GFL and GFM PV energy storage VSG systems were established,and grid stability was analyzed.Second,an online impedance identification method based on voltage fluctuation data screening was proposed to enhance the accuracy of impedance identification.Additionally,a PV energy storage GFM/GFL VSG smooth switching method based on current inner loop compensation was introduced to achieve stable grid-connected operation of distributed photovoltaics under changes in strong and weak power grids.Finally,a grid stability analysis was conducted on the multi-machine parallel PV ESS,and a simulation model of a multi-machine parallel PV ESS based on current inner loop compensation was established for testing.Results showed that,compared to using a single GFM or single GFL control for the PV VSG system,the smooth switching method of multi-machine parallel PV ESS effectively suppresses system resonance under variations in power grid strength,enabling adaptive and stable grid-connected operations of distributed PV.
基金supported by the China Southern Power Grid Science and Technology Project,Research on 230 MHz Iot Access Architecture for Deep Coverage of Power Edge Services and R&D of Key Communication Devices(No.036000KK52180036).
文摘A decision feedback equalization(DFE)algorithm is proposed by simplifying Volterra structure.The simplification principle and process of the proposed Volterra-based equalization algorithm are presented.With the support of this algorithm,the signal damage for four-level pulse amplitude modulation signal(PAM-4)is compensated,which is caused by device bandwidth limitation and dispersion during transmission in C-band intensity modulation direct detection(IM-DD)fiber system.Experiments have been carried out to demonstrate that PAM-4 signals can transmit over 2 km in standard single-mode fiber(SSMF)based on a 30 GHz Mach-Zehnder modulator(MZM).The bit error rate(BER)can reach the threshold of hard decision-forward error correction(HD-FEC)(BER=3.8×10-3)and its sensitivity is reduced by 2 d Bm compared with traditional feedforward equalization(FFE).Meanwhile,the algorithm complexity is greatly reduced by 55%,which provides an effective theoretical support for the commercial application of the algorithm.
基金funded by the Guangdong Power Grid Co.,Ltd.Technology Project(GDKJXM20180019).
文摘With a lack of coverage in private and public power communication networks,especially for collection of information from hydropower stations in remote areas,communication coverage is a significant issue.Satellite communication provides a large coverage area suitable for a variety of services and is less affected by geographical factors;moreover,the costs are independent of the communication distance.This study investigates information acquisition technology for small hydropower stations in remote areas using high-and low-orbit satellites.The information collection needs of small hydropower stations in remote areas are analyzed,and an information acquisition system is designed using high-and low-orbit satellites.For network security protection,network anomaly detection technology based on a support vector machine algorithm is proposed.The effectiveness of information collection was evaluated and verified for small hydropower plants in remote areas.The system provides technical support for“full coverage,full collection,and full monitoring”of the measurement automation information acquisition system.
基金supported by the National Natural Science Foundation of China [grant number 42088101]the National Key R&D Program of China [grant number 2018YFC1505604]the National Natural Science Foundation of China [grant numbers 42005016 and 41905061]。
文摘By using electric power data,observational station temperature data in Beijing,CN05.1 temperature data,ERA5 atmospheric reanalysis data,and ERSST.v3 b sea surface temperature(SST) data,it is found that summer(JulyAugust) electric power demand in Beijing is remarkably positively correlated with the previous spring(MarchApril) tropical North Atlantic(TNA) SST anomaly(SSTA).The possible physical mechanism of the TNA SSTA affecting summer electric power in Beijing is also revealed.When a positive SSTA occurs in the TNA during spring,anomalous easterlies prevail over the tropical central Pacific,which can persist to the following summer.Trade winds are thus enhanced over the northern Pacific,which favors a strengthening of upwelling cold water in the tropical central-eastern Pacific.As a result,a negative SSTA appears in the central-eastern Pacific in summer,which means a La Nina event is triggered by the previous TNA SSTA through the Bjerknes feedback.During the La Nina event,an anomalous anticyclonic circulation occupies the northwestern Pacific.The southerly anomalies at the western edge of this anomalous anticyclone strengthen the transportation of warm and humid airflow from the low latitudes to North China,where Beijing is located,causing higher summer temperatures and increased electricity usage for air conditioning,and vice versa.The results of this study might provide a new scientific basis and dues for the seasonal prediction of summer electric power demand in Beijing.
基金supported by National High Technology Research and Development Program of China (863 Program) (No.2011AA05A118)
文摘Because of the large-scale integration of wind power,the dynamic characteristics of power system have many uncertain effects.Based on deterministic analysis methods,traditional on-line security assessment system cannot quantitatively estimate the actual operating conditions of the power system for only considering the most serious and credible accidents.Therefore,the risk theory is introduced into an on-line security assessment system and then an on-line risk assessment system for wind power is designed and implemented by combining with the dynamic security assessment system.Based on multiple data integration,the wind power disturbance probability is available and the security assessment of the power grid can obtain security indices in different aspects.The operating risk index is an expectation of severity,computed by summing up all the products of the result probability and its severity.Analysis results are reported to the dispatchers in on-line environment,while the comprehensive weak links are automatically provided to the power dispatching center.The risk assessment system in operation can verify the reasonableness of the system.
基金Platform for Meteorological Prediction of Power Load in Guangdong Province
文摘The variability characteristics of Guangdong daily power load from 2002 to 2004 and its connection to meteorological variables are analyzed with wavelet analysis and correlation analysis. Prediction equations are established using optimization subset regression. The results show that a linear increasing trend is very significant and seasonal change is obvious. The power load exhibits significant quasi-weekly (5 – 7 days) oscillation, quasi-by-weekly (10 – 20 days) oscillation and intraseasonal (30 – 60 days) oscillation. These oscillations are caused by atmospheric low frequency oscillation and public holidays. The variation of Guangdong daily power load is obviously in decrease on Sundays, shaping like a funnel during Chinese New Year in particular. The minimum is found at the first and second day and the power load gradually increases to normal level after the third day during the long vacation of Labor Day and National Day. Guangdong power load is the most sensitive to temperature, which is the main affecting factor, as in other areas in China. The power load also has relationship with other meteorological elements to some extent during different seasons. The maximum of power load in summer, minimum during Chinese New Year and variation during Labor Day and National Day are well fitted and predicted using the equation established by optimization subset regression and accounting for the effect of workdays and holidays.
