Hui Ren - Profile on Academia.edu (original) (raw)
Papers by Hui Ren
Proceedings of the 51st Hawaii International Conference on System Sciences, 2018
The paper studies the reliability of the power system from the perspective of node loads. The rel... more The paper studies the reliability of the power system from the perspective of node loads. The reliability of the whole system can be estimated by evaluating the power supply reliability of each node. A measure, "connectivity" observed at load node (Ci), is proposed. Ci is calculated through a recursion equation by evaluating the generation capacity that can be transferred from the further neighbor to the nearest neighbor of load node i. IEEE-30 bus system is taken as a test system. We calculated the index of 7 load nodes at 2 different load levels with different N-1 failures. The test results show that the variation of the index and that of the percentage load shedding at selected load nodes show good consistency.
Energies, 2020
Solar photovoltaic (PV) power generation has strong intermittency and volatility due to its high ... more Solar photovoltaic (PV) power generation has strong intermittency and volatility due to its high dependence on solar radiation and other meteorological factors. Therefore, the negative impact of grid-connected PV on power systems has become one of the constraints in the development of large scale PV systems. Accurate forecasting of solar power generation and flexible planning and operational measures are of great significance to ensure safe, stable, and economical operation of a system with high penetration of solar generation at transmission and distribution levels. In this paper, studies on the following aspects are reviewed: (1) this paper comprehensively expounds the research on forecasting techniques of PV power generation output. (2) In view of the new challenge brought by the integration of high proportion solar generation to the frequency stability of power grid, this paper analyzes the mechanisms of influence between them and introduces the current technical route of PV pow...
2018 IEEE Industry Applications Society Annual Meeting (IAS), 2018
In recent years, with the vigorous development of the new energy industry in the world, distribut... more In recent years, with the vigorous development of the new energy industry in the world, distributed photovoltaics (PV) have strongly penetrated the international energy markets at exponential growth rates, and a large number of electric vehicles (EVs) have been used mainly driven by policies. The use of EVs and distributed PV would lead to an increase in load uncertainty. Hence, a new day-ahead portfolio optimization model for a power supply company with distributed PV considering EVs was developed. The model contains risks depending on market price fluctuation and load uncertainty caused by EVs load, conventional load and distributed PV's output, considering the expected cost of errors, and helping to determine an optimal quantity of power to be obtained from distributed PV's output and different electricity markets. This paper analyses the efficient frontier of conditional value-at-risk (CVaR) and the influence of different EVs market penetration levels and distributed PV&...
Energies, May 18, 2018
Sharing the benefits of distribution systems from the integration of distributed photovoltaic sys... more Sharing the benefits of distribution systems from the integration of distributed photovoltaic systems (DGPVs) with investors is vital to the coordinated development of DGPVs and active distribution systems (ADN). The investment and development of DGPVs, incentive policies, and the development of distribution system interact, and the interactions vary with the changes in the on-grid capacity of DGPVs. In this paper, an event-driven co-simulation platform is built to simulate the abovementioned interaction among DGPVs, ADN, and incentive policy under a long-term time frame. The platform includes an investment model of DGPV investors and an ADN model with consideration of the growth of the ADN. On this platform, we study how multiple factors, including incentive system, global horizontal radiance (GHR), and cost, affect the investment and integration of DGPVs in the future 10 years. Simulation and analysis showed that investors' decisions are more sensitive to variation in GHR and cost, followed by variation in tariff system, subsidy, and self-use ratio. Distribution subsidies have certain impact on the development of DGPV and could partially replace the national and provincial capacity and generation subsidies. When the on-grid capacity reaches a certain level, the distribution subsidy reaches a dynamic equilibrium.
Energies, 2018
This paper aims to identity the significant impact factors (IFs) of the residential electricity c... more This paper aims to identity the significant impact factors (IFs) of the residential electricity consumption level (RECL) and to better understand the influence mechanism of IFs on RECL. The analysis of influence mechanism is commonly through regression model where feature selection must first be performed to pick out non-redundant IFs that is highly correlated with RECL. In contrast to the existing studies, this study recognizes the problem that majority feature selection methods (e.g., step regression) are limited to the identification of linear relationships and proposes a novel wrapper feature selection (WFS) method to address this issue. The WFS is based on genetic algorithm (GA) and multinomial logistic regression (MLR). GA is a searching algorithm used to generate different feature subsets (FSs) that consist of several IFs. MLR is a modeling algorithm used to score these FSs. Further, maximal information coefficient (MIC) is utilized to verify the validity of WFS for selecting IFs. Finally, MLR based explanatory model is established to excavate the relationship between selected IFs and RECL. The results of Ireland dataset based case study show that WFS can identify the significant and non-redundant IFs that are linearly or nonlinearly related to RECL. The details about how selected IFs affect RECL are also provided via the explanatory model. Such research can provide useful guidance for a wide range of stakeholders including local governments, electric power companies, and individual households.
Energies, 2017
To address the static voltage stability issue and suppress the voltage fluctuation caused by the ... more To address the static voltage stability issue and suppress the voltage fluctuation caused by the increasing integration of wind farms and solar photovoltaic (PV) power plants, a two-tier reactive power and voltage control strategy based on ARMA power forecasting models for wind and solar plants is proposed in this paper. Firstly, ARMA models are established to forecast the output of wind farms and solar PV plants. Secondly, the discrete equipment is pre-regulated based on the single-step prediction information from ARMA forecasting models according to the optimization result. Thirdly, a multi-objective optimization model is presented and solved by particle swarm optimization (PSO) according to the measured data and the proposed static voltage stability index. Finally, the IEEE14 bus system including a wind farm and solar PV plant is utilized to test the effectiveness of the proposed strategy. The results show that the proposed strategy can suppress voltage fluctuation and improve the static voltage stability under the condition of high penetration of renewables including wind and solar power.
Energies, 2019
An active distribution network (ADN) differs from a traditional distribution network in many aspe... more An active distribution network (ADN) differs from a traditional distribution network in many aspects, one of which is the integration of a large amount of distributed generation (DG), especially intermittent photovoltaics (PVs). The integration of intermittent PVs has both pros and cons for the distribution system. As the platform on which new techniques work and the main body of a greener future energy system, the development of an ADN has to be sustainable, need-oriented, and environmentally friendly, and the traditional technical–economic evaluation method cannot meet the requirements and provide advice in the decision-making process. Based on the concept of sustainable development, we used an ADN with the integration of a large number of distributed PVs (DGPVs) as an example and established a multi-dimensional index system to evaluate the sustainable development level (SDI) of the ADN. The analysis was based on a platform we built with consideration of the investment feasibility...
Energies, 2017
The optimal dispatching model for a stand-alone microgrid (MG) is of great importance to its oper... more The optimal dispatching model for a stand-alone microgrid (MG) is of great importance to its operation reliability and economy. This paper aims at addressing the difficulties in improving the operational economy and maintaining the power balance under uncertain load demand and renewable generation, which could be even worse in such abnormal conditions as storms or abnormally low or high temperatures. A new two-time scale multi-objective optimization model, including day-ahead cursory scheduling and real-time scheduling for finer adjustments, is proposed to optimize the operational cost, load shedding compensation and environmental benefit of stand-alone MG through controllable load (CL) and multi-distributed generations (DGs). The main novelty of the proposed model is that the synergetic response of CL and energy storage system (ESS) in real-time scheduling offset the operation uncertainty quickly. And the improved dispatch strategy for combined cooling-heating-power (CCHP) enhanced the system economy while the comfort is guaranteed. An improved algorithm, Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy (SIP-CO-PSO-ERS) algorithm with strong searching capability and fast convergence speed, was presented to deal with the problem brought by the increased errors between actual renewable generation and load and prior predictions. Four typical scenarios are designed according to the combinations of day types (work day or weekend) and weather categories (sunny or rainy) to verify the performance of the presented dispatch strategy. The simulation results show that the proposed two-time scale model and SIP-CO-PSO-ERS algorithm exhibit better performance in adaptability, convergence speed and search ability than conventional methods for the stand-alone MG's operation.
Energy and Power Engineering, 2013
Studying the propagation of cascading failures through the transmission network is key to asses a... more Studying the propagation of cascading failures through the transmission network is key to asses and mitigate the risk faced the energy system. As complex systems the power grid failure is often studied using some probability distributions. We apply 4 well-known probabilistic models, Poisson model, Power Law model, Generalized Poisson Branching process model and Borel-Tanner Branching process model, to a 14-year utility historical outage data from a regional power grid in China, computing probabilities of cascading line outages. For this data, the empirical distribution of the total number of line outages is well approximated by the initial line outages propagating according to a Borel-Tanner branching process. Also for this data, Power law model overestimates, while Generalized Possion branching process and Possion model underestimate, the probability of larger outages. Especially, the probability distribution generated by the Poisson model deviates heavily from the observed data, underestimating the probability of large events (total no. of outages over 5) by roughly a factor of 10-2 to 10-5. The observation is confirmed by a statistical test of model fitness. The results of this work indicate that further testing of Borel-Tanner branching process models of cascading failure is appropriate, and should be further discussed as it outperforms other more traditional models.
A novel power system FDI scheme based on Petri nets and coding theory
2004 International Conference on Power System Technology, 2004. PowerCon 2004.
ABSTRACT
Modeling and analysis of power system events
2006 IEEE Power Engineering Society General Meeting, 2006
ABSTRACT
A Review of FACTS' Practical Consideration and Economic Evaluation
2009 Asia-Pacific Power and Energy Engineering Conference, 2009
... These models are proposed for the correct representation of SVCs and TCSCs in voltage collaps... more ... These models are proposed for the correct representation of SVCs and TCSCs in voltage collapse studies. ... 146, pp. 428-434, 1999. [29] S. Gerbex, R. Cherkaoui, and AJ Germond, "Optimal location of multi-type FACTS devices in a power system by means of genetic ...
Fault diagnosis for substation automation based on Petri nets and coding theory
In this paper, coding-based methodology for faults monitoring of discrete event systems is applie... more In this paper, coding-based methodology for faults monitoring of discrete event systems is applied to electric power system. Using Petri nets and coding theory to perform the fault diagnosis is further studied. One feeder of the substation is modeled by Petri net using real time discrete events, and redundant places are introduced to form structure redundancy and facilitate fault diagnosis. Based on the previous work, the feeder's all possible failures are analyzed and a new method to model these failures is given. Then parity check from coding theory is used to form an encoded Petri net, therefore faults can be detected and identified through error syndrome. Method to construct important matrix, generator matrix, is presented. The simulation is simple, fast and shows very high accuracy, as combining with error correction theory. The result of simulation shows that the scheme has good performance in real-time substation fault diagnosis.
Renewable Energy especially wind energy integration has attained profound growth across the world... more Renewable Energy especially wind energy integration has attained profound growth across the worldwide power system. Wind energy integration at large scale comes up with the challenge on voltages and reactive power management at power system level. The research work presented in this paper has analyzed the impact of wind energy on reactive power reserve with special reference to Hebei Southern Power System. The maximum wind power integration capacity is calculated, and the effect of increasing wind power integration on voltage profiles is studied. Possible controls from system sides and its effects on wind power integration are explored. Study shows that with the increase of the wind power integration capacity, the intermittency and variation will bring more serious problems to the system frequency regulation, reserve service and voltage control. These problems also become the limiting factors for further increase of large-scale wind power integration. In order to make a better use of wind power resources in Heibei province and maintain system safety at the same time, further research should be performed on exploring the reactive and active power regulation and control of the wind farm and the methods to decrease the variability of wind farm outputs.
Proceedings of the 51st Hawaii International Conference on System Sciences, 2018
The paper studies the reliability of the power system from the perspective of node loads. The rel... more The paper studies the reliability of the power system from the perspective of node loads. The reliability of the whole system can be estimated by evaluating the power supply reliability of each node. A measure, "connectivity" observed at load node (Ci), is proposed. Ci is calculated through a recursion equation by evaluating the generation capacity that can be transferred from the further neighbor to the nearest neighbor of load node i. IEEE-30 bus system is taken as a test system. We calculated the index of 7 load nodes at 2 different load levels with different N-1 failures. The test results show that the variation of the index and that of the percentage load shedding at selected load nodes show good consistency.
Energies, 2020
Solar photovoltaic (PV) power generation has strong intermittency and volatility due to its high ... more Solar photovoltaic (PV) power generation has strong intermittency and volatility due to its high dependence on solar radiation and other meteorological factors. Therefore, the negative impact of grid-connected PV on power systems has become one of the constraints in the development of large scale PV systems. Accurate forecasting of solar power generation and flexible planning and operational measures are of great significance to ensure safe, stable, and economical operation of a system with high penetration of solar generation at transmission and distribution levels. In this paper, studies on the following aspects are reviewed: (1) this paper comprehensively expounds the research on forecasting techniques of PV power generation output. (2) In view of the new challenge brought by the integration of high proportion solar generation to the frequency stability of power grid, this paper analyzes the mechanisms of influence between them and introduces the current technical route of PV pow...
2018 IEEE Industry Applications Society Annual Meeting (IAS), 2018
In recent years, with the vigorous development of the new energy industry in the world, distribut... more In recent years, with the vigorous development of the new energy industry in the world, distributed photovoltaics (PV) have strongly penetrated the international energy markets at exponential growth rates, and a large number of electric vehicles (EVs) have been used mainly driven by policies. The use of EVs and distributed PV would lead to an increase in load uncertainty. Hence, a new day-ahead portfolio optimization model for a power supply company with distributed PV considering EVs was developed. The model contains risks depending on market price fluctuation and load uncertainty caused by EVs load, conventional load and distributed PV's output, considering the expected cost of errors, and helping to determine an optimal quantity of power to be obtained from distributed PV's output and different electricity markets. This paper analyses the efficient frontier of conditional value-at-risk (CVaR) and the influence of different EVs market penetration levels and distributed PV&...
Energies, May 18, 2018
Sharing the benefits of distribution systems from the integration of distributed photovoltaic sys... more Sharing the benefits of distribution systems from the integration of distributed photovoltaic systems (DGPVs) with investors is vital to the coordinated development of DGPVs and active distribution systems (ADN). The investment and development of DGPVs, incentive policies, and the development of distribution system interact, and the interactions vary with the changes in the on-grid capacity of DGPVs. In this paper, an event-driven co-simulation platform is built to simulate the abovementioned interaction among DGPVs, ADN, and incentive policy under a long-term time frame. The platform includes an investment model of DGPV investors and an ADN model with consideration of the growth of the ADN. On this platform, we study how multiple factors, including incentive system, global horizontal radiance (GHR), and cost, affect the investment and integration of DGPVs in the future 10 years. Simulation and analysis showed that investors' decisions are more sensitive to variation in GHR and cost, followed by variation in tariff system, subsidy, and self-use ratio. Distribution subsidies have certain impact on the development of DGPV and could partially replace the national and provincial capacity and generation subsidies. When the on-grid capacity reaches a certain level, the distribution subsidy reaches a dynamic equilibrium.
Energies, 2018
This paper aims to identity the significant impact factors (IFs) of the residential electricity c... more This paper aims to identity the significant impact factors (IFs) of the residential electricity consumption level (RECL) and to better understand the influence mechanism of IFs on RECL. The analysis of influence mechanism is commonly through regression model where feature selection must first be performed to pick out non-redundant IFs that is highly correlated with RECL. In contrast to the existing studies, this study recognizes the problem that majority feature selection methods (e.g., step regression) are limited to the identification of linear relationships and proposes a novel wrapper feature selection (WFS) method to address this issue. The WFS is based on genetic algorithm (GA) and multinomial logistic regression (MLR). GA is a searching algorithm used to generate different feature subsets (FSs) that consist of several IFs. MLR is a modeling algorithm used to score these FSs. Further, maximal information coefficient (MIC) is utilized to verify the validity of WFS for selecting IFs. Finally, MLR based explanatory model is established to excavate the relationship between selected IFs and RECL. The results of Ireland dataset based case study show that WFS can identify the significant and non-redundant IFs that are linearly or nonlinearly related to RECL. The details about how selected IFs affect RECL are also provided via the explanatory model. Such research can provide useful guidance for a wide range of stakeholders including local governments, electric power companies, and individual households.
Energies, 2017
To address the static voltage stability issue and suppress the voltage fluctuation caused by the ... more To address the static voltage stability issue and suppress the voltage fluctuation caused by the increasing integration of wind farms and solar photovoltaic (PV) power plants, a two-tier reactive power and voltage control strategy based on ARMA power forecasting models for wind and solar plants is proposed in this paper. Firstly, ARMA models are established to forecast the output of wind farms and solar PV plants. Secondly, the discrete equipment is pre-regulated based on the single-step prediction information from ARMA forecasting models according to the optimization result. Thirdly, a multi-objective optimization model is presented and solved by particle swarm optimization (PSO) according to the measured data and the proposed static voltage stability index. Finally, the IEEE14 bus system including a wind farm and solar PV plant is utilized to test the effectiveness of the proposed strategy. The results show that the proposed strategy can suppress voltage fluctuation and improve the static voltage stability under the condition of high penetration of renewables including wind and solar power.
Energies, 2019
An active distribution network (ADN) differs from a traditional distribution network in many aspe... more An active distribution network (ADN) differs from a traditional distribution network in many aspects, one of which is the integration of a large amount of distributed generation (DG), especially intermittent photovoltaics (PVs). The integration of intermittent PVs has both pros and cons for the distribution system. As the platform on which new techniques work and the main body of a greener future energy system, the development of an ADN has to be sustainable, need-oriented, and environmentally friendly, and the traditional technical–economic evaluation method cannot meet the requirements and provide advice in the decision-making process. Based on the concept of sustainable development, we used an ADN with the integration of a large number of distributed PVs (DGPVs) as an example and established a multi-dimensional index system to evaluate the sustainable development level (SDI) of the ADN. The analysis was based on a platform we built with consideration of the investment feasibility...
Energies, 2017
The optimal dispatching model for a stand-alone microgrid (MG) is of great importance to its oper... more The optimal dispatching model for a stand-alone microgrid (MG) is of great importance to its operation reliability and economy. This paper aims at addressing the difficulties in improving the operational economy and maintaining the power balance under uncertain load demand and renewable generation, which could be even worse in such abnormal conditions as storms or abnormally low or high temperatures. A new two-time scale multi-objective optimization model, including day-ahead cursory scheduling and real-time scheduling for finer adjustments, is proposed to optimize the operational cost, load shedding compensation and environmental benefit of stand-alone MG through controllable load (CL) and multi-distributed generations (DGs). The main novelty of the proposed model is that the synergetic response of CL and energy storage system (ESS) in real-time scheduling offset the operation uncertainty quickly. And the improved dispatch strategy for combined cooling-heating-power (CCHP) enhanced the system economy while the comfort is guaranteed. An improved algorithm, Search Improvement Process-Chaotic Optimization-Particle Swarm Optimization-Elite Retention Strategy (SIP-CO-PSO-ERS) algorithm with strong searching capability and fast convergence speed, was presented to deal with the problem brought by the increased errors between actual renewable generation and load and prior predictions. Four typical scenarios are designed according to the combinations of day types (work day or weekend) and weather categories (sunny or rainy) to verify the performance of the presented dispatch strategy. The simulation results show that the proposed two-time scale model and SIP-CO-PSO-ERS algorithm exhibit better performance in adaptability, convergence speed and search ability than conventional methods for the stand-alone MG's operation.
Energy and Power Engineering, 2013
Studying the propagation of cascading failures through the transmission network is key to asses a... more Studying the propagation of cascading failures through the transmission network is key to asses and mitigate the risk faced the energy system. As complex systems the power grid failure is often studied using some probability distributions. We apply 4 well-known probabilistic models, Poisson model, Power Law model, Generalized Poisson Branching process model and Borel-Tanner Branching process model, to a 14-year utility historical outage data from a regional power grid in China, computing probabilities of cascading line outages. For this data, the empirical distribution of the total number of line outages is well approximated by the initial line outages propagating according to a Borel-Tanner branching process. Also for this data, Power law model overestimates, while Generalized Possion branching process and Possion model underestimate, the probability of larger outages. Especially, the probability distribution generated by the Poisson model deviates heavily from the observed data, underestimating the probability of large events (total no. of outages over 5) by roughly a factor of 10-2 to 10-5. The observation is confirmed by a statistical test of model fitness. The results of this work indicate that further testing of Borel-Tanner branching process models of cascading failure is appropriate, and should be further discussed as it outperforms other more traditional models.
A novel power system FDI scheme based on Petri nets and coding theory
2004 International Conference on Power System Technology, 2004. PowerCon 2004.
ABSTRACT
Modeling and analysis of power system events
2006 IEEE Power Engineering Society General Meeting, 2006
ABSTRACT
A Review of FACTS' Practical Consideration and Economic Evaluation
2009 Asia-Pacific Power and Energy Engineering Conference, 2009
... These models are proposed for the correct representation of SVCs and TCSCs in voltage collaps... more ... These models are proposed for the correct representation of SVCs and TCSCs in voltage collapse studies. ... 146, pp. 428-434, 1999. [29] S. Gerbex, R. Cherkaoui, and AJ Germond, "Optimal location of multi-type FACTS devices in a power system by means of genetic ...
Fault diagnosis for substation automation based on Petri nets and coding theory
In this paper, coding-based methodology for faults monitoring of discrete event systems is applie... more In this paper, coding-based methodology for faults monitoring of discrete event systems is applied to electric power system. Using Petri nets and coding theory to perform the fault diagnosis is further studied. One feeder of the substation is modeled by Petri net using real time discrete events, and redundant places are introduced to form structure redundancy and facilitate fault diagnosis. Based on the previous work, the feeder's all possible failures are analyzed and a new method to model these failures is given. Then parity check from coding theory is used to form an encoded Petri net, therefore faults can be detected and identified through error syndrome. Method to construct important matrix, generator matrix, is presented. The simulation is simple, fast and shows very high accuracy, as combining with error correction theory. The result of simulation shows that the scheme has good performance in real-time substation fault diagnosis.
Renewable Energy especially wind energy integration has attained profound growth across the world... more Renewable Energy especially wind energy integration has attained profound growth across the worldwide power system. Wind energy integration at large scale comes up with the challenge on voltages and reactive power management at power system level. The research work presented in this paper has analyzed the impact of wind energy on reactive power reserve with special reference to Hebei Southern Power System. The maximum wind power integration capacity is calculated, and the effect of increasing wind power integration on voltage profiles is studied. Possible controls from system sides and its effects on wind power integration are explored. Study shows that with the increase of the wind power integration capacity, the intermittency and variation will bring more serious problems to the system frequency regulation, reserve service and voltage control. These problems also become the limiting factors for further increase of large-scale wind power integration. In order to make a better use of wind power resources in Heibei province and maintain system safety at the same time, further research should be performed on exploring the reactive and active power regulation and control of the wind farm and the methods to decrease the variability of wind farm outputs.