Pub Date : 2023-10-13DOI: 10.35833/MPCE.2023.000057
Qing Ma;Changhong Deng
Volt-var control (VVC) is essentially a non-convex optimization problem due to the non-convexity of power flow (PF) constraints, resulting in the difficulty in obtaining the optimum without convexity conversion. The existing second-order cone method for the convexity conversion often leads to a sharp increase in PF constraints and optimization variables, which in turn increases the optimization difficulty or even leads to optimization failure. This paper first proposes a deterministic VVC method based on convex deep learning power flow (DLPF). This method uses the input convex neural network (ICNN) to establish a single convex mapping between state parameters and node voltage to complete the convexity conversion while the optimization variables only correspond to reactive power equipment, which can ensure the global optimum with extremely fast computation speed. To cope with the impact brought by the uncertainty of distributed energy and omit the additional worst scenario search of traditional robust VVC, this paper proposes robust VVC method based on convex deep learning interval power flow (DLIPF), which continues to adopt ICNN to establish another convex mapping between state parameters and node voltage interval. Combining DLIPF with DLPF, this method decreases the modeling and optimization difficulty of robust VVC significantly. Test results on 30-bus, 118-bus, and 200-bus systems prove the correctness and rapidity of the proposed methods.
{"title":"Deterministic and Robust Volt-var Control Methods of Power System Based on Convex Deep Learning","authors":"Qing Ma;Changhong Deng","doi":"10.35833/MPCE.2023.000057","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000057","url":null,"abstract":"Volt-var control (VVC) is essentially a non-convex optimization problem due to the non-convexity of power flow (PF) constraints, resulting in the difficulty in obtaining the optimum without convexity conversion. The existing second-order cone method for the convexity conversion often leads to a sharp increase in PF constraints and optimization variables, which in turn increases the optimization difficulty or even leads to optimization failure. This paper first proposes a deterministic VVC method based on convex deep learning power flow (DLPF). This method uses the input convex neural network (ICNN) to establish a single convex mapping between state parameters and node voltage to complete the convexity conversion while the optimization variables only correspond to reactive power equipment, which can ensure the global optimum with extremely fast computation speed. To cope with the impact brought by the uncertainty of distributed energy and omit the additional worst scenario search of traditional robust VVC, this paper proposes robust VVC method based on convex deep learning interval power flow (DLIPF), which continues to adopt ICNN to establish another convex mapping between state parameters and node voltage interval. Combining DLIPF with DLPF, this method decreases the modeling and optimization difficulty of robust VVC significantly. Test results on 30-bus, 118-bus, and 200-bus systems prove the correctness and rapidity of the proposed methods.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 3","pages":"719-729"},"PeriodicalIF":6.3,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10285627","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141091168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.35833/MPCE.2023.000213
Jie Xu;Hongjun Gao;Renjun Wang;Junyong Liu
The increasing integration of intermittent renewable energy sources (RESs) poses great challenges to active distribution networks (ADNs), such as frequent voltage fluctuations. This paper proposes a novel ADN strategy based on multi-agent deep reinforcement learning (MADRL), which harnesses the regulating function of switch state transitions for the real-time voltage regulation and loss minimization. After deploying the calculated optimal switch topologies, the distribution network operator will dynamically adjust the distributed energy resources (DERs) to enhance the operation performance of ADNs based on the policies trained by the MADRL algorithm. Owing to the model-free characteristics and the generalization of deep reinforcement learning, the proposed strategy can still achieve optimization objectives even when applied to similar but unseen environments. Additionally, integrating parameter sharing (PS) and prioritized experience replay (PER) mechanisms substantially improves the strategic performance and scalability. This framework has been tested on modified IEEE 33-bus, IEEE 118-bus, and three-phase unbalanced 123-bus systems. The results demonstrate the significant real-time regulation capabilities of the proposed strategy.
{"title":"Real-Time Operation Optimization in Active Distribution Networks Based on Multi-Agent Deep Reinforcement Learning","authors":"Jie Xu;Hongjun Gao;Renjun Wang;Junyong Liu","doi":"10.35833/MPCE.2023.000213","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000213","url":null,"abstract":"The increasing integration of intermittent renewable energy sources (RESs) poses great challenges to active distribution networks (ADNs), such as frequent voltage fluctuations. This paper proposes a novel ADN strategy based on multi-agent deep reinforcement learning (MADRL), which harnesses the regulating function of switch state transitions for the real-time voltage regulation and loss minimization. After deploying the calculated optimal switch topologies, the distribution network operator will dynamically adjust the distributed energy resources (DERs) to enhance the operation performance of ADNs based on the policies trained by the MADRL algorithm. Owing to the model-free characteristics and the generalization of deep reinforcement learning, the proposed strategy can still achieve optimization objectives even when applied to similar but unseen environments. Additionally, integrating parameter sharing (PS) and prioritized experience replay (PER) mechanisms substantially improves the strategic performance and scalability. This framework has been tested on modified IEEE 33-bus, IEEE 118-bus, and three-phase unbalanced 123-bus systems. The results demonstrate the significant real-time regulation capabilities of the proposed strategy.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 3","pages":"886-899"},"PeriodicalIF":6.3,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10272359","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141091155","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.35833/MPCE.2023.000412
Dalin Mu;Sheng Lin;Xiaopeng Li
The hybrid cascaded high-voltage direct current (HVDC) transmission system has various operation modes, and some operation modes are having sharply increasing requirements for protection rapidity, while the traditional pilot differential protection (PDP) has poor rapidity, and even refuses to operate when faults occur on the DC line. Therefore, a novel pilot protection scheme based on traveling wave characteristics is proposed. First, the adaptability of the traditional PDP applied in engineering is analyzed for different operation modes. Then, the expressions of the forward traveling wave (FTW) and backward traveling wave (BTW) on the rectifier side and the inverter side are derived for different fault locations. From the theoretical derivation, the difference between the BTW and FTW on the rectifier side is less than zero, and the same is true on the inverter side. However, in the event of an external fault of DC line, the difference between the BTW and FTW at near-fault terminal protection installation point is greater than zero. Therefore, by summing over the product of the difference between BTW and FTW of the rectifier side and that of the inverter side, the fault identification criterion is constructed. The simulation results show that the proposed pilot protection scheme can quickly and reliably identify the short-circuit faults of DC line in different operation modes.
{"title":"Traveling Wave Characteristics Based Pilot Protection Scheme for Hybrid Cascaded HVDC Transmission Line","authors":"Dalin Mu;Sheng Lin;Xiaopeng Li","doi":"10.35833/MPCE.2023.000412","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000412","url":null,"abstract":"The hybrid cascaded high-voltage direct current (HVDC) transmission system has various operation modes, and some operation modes are having sharply increasing requirements for protection rapidity, while the traditional pilot differential protection (PDP) has poor rapidity, and even refuses to operate when faults occur on the DC line. Therefore, a novel pilot protection scheme based on traveling wave characteristics is proposed. First, the adaptability of the traditional PDP applied in engineering is analyzed for different operation modes. Then, the expressions of the forward traveling wave (FTW) and backward traveling wave (BTW) on the rectifier side and the inverter side are derived for different fault locations. From the theoretical derivation, the difference between the BTW and FTW on the rectifier side is less than zero, and the same is true on the inverter side. However, in the event of an external fault of DC line, the difference between the BTW and FTW at near-fault terminal protection installation point is greater than zero. Therefore, by summing over the product of the difference between BTW and FTW of the rectifier side and that of the inverter side, the fault identification criterion is constructed. The simulation results show that the proposed pilot protection scheme can quickly and reliably identify the short-circuit faults of DC line in different operation modes.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 3","pages":"971-980"},"PeriodicalIF":6.3,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10272361","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141091160","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-05DOI: 10.35833/MPCE.2023.000306
Mubarak J. Al-Mubarak;Antonio J. Conejo
We consider a power system whose electric demand pertaining to freshwater production is high (high freshwater electric demand), as in the Middle East, and investigate the tradeoff of storing freshwater in tanks versus storing electricity in batteries at the day-ahead operation stage. Both storing freshwater and storing electricity increase the actual electric demand at valley hours and decrease it at peak hours, which is generally beneficial in term of cost and reliability. But, to what extent? We analyze this question considering three power systems with different generation-mix configurations, i. e., a thermal-dominated mix, a renewable-dominated one, and a fully renewable one. These generation-mix configurations are inspired by how power systems may evolve in different countries in the Middle East. Renewable production uncertainty is compactly modeled using chance constraints. We draw conclusions on how both storage facilities (freshwater and electricity) complement each other to render an optimal operation of the power system.
{"title":"Storing Freshwater Versus Storing Electricity in Power Systems with High Freshwater Electric Demand","authors":"Mubarak J. Al-Mubarak;Antonio J. Conejo","doi":"10.35833/MPCE.2023.000306","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000306","url":null,"abstract":"We consider a power system whose electric demand pertaining to freshwater production is high (high freshwater electric demand), as in the Middle East, and investigate the tradeoff of storing freshwater in tanks versus storing electricity in batteries at the day-ahead operation stage. Both storing freshwater and storing electricity increase the actual electric demand at valley hours and decrease it at peak hours, which is generally beneficial in term of cost and reliability. But, to what extent? We analyze this question considering three power systems with different generation-mix configurations, i. e., a thermal-dominated mix, a renewable-dominated one, and a fully renewable one. These generation-mix configurations are inspired by how power systems may evolve in different countries in the Middle East. Renewable production uncertainty is compactly modeled using chance constraints. We draw conclusions on how both storage facilities (freshwater and electricity) complement each other to render an optimal operation of the power system.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 2","pages":"323-333"},"PeriodicalIF":6.3,"publicationDate":"2023-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10272360","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140291172","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-04DOI: 10.35833/MPCE.2023.000085
Paranagamage S. A. Peiris;Shaahin Filizadeh;Dharshana Muthumuni
Power converters and their interfacing networks are often treated as modular state-space blocks for small-signal stability studies in microgrids; they are interconnected by matching the input and output states of the network and converters. Virtual resistors have been widely used in existing models to generate a voltage for state-space models of the network that require voltage inputs. This paper accurately quantifies the adverse impacts of adding the virtual resistance and proposes an alternative method for network modelling that eliminates the requirement of the virtual resistor when interfacing converters with microgrids. The proposed nonlinear method allows initialization, time-domain simulations of the nonlinear model, and linearization and eigenvalue generation. A numerically linearized small-signal model is used to generate eigenvalues and is compared with the eigenvalues generated using the existing modelling method with virtual resistances. Deficiencies of the existing method and improvements offered by the proposed modelling method are clearly quantified. Electromagnetic transient (EMT) simulations using detailed switching models are used for validation of the proposed modelling method.
{"title":"Improved State-space Modelling for Microgrids Without Virtual Resistances","authors":"Paranagamage S. A. Peiris;Shaahin Filizadeh;Dharshana Muthumuni","doi":"10.35833/MPCE.2023.000085","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000085","url":null,"abstract":"Power converters and their interfacing networks are often treated as modular state-space blocks for small-signal stability studies in microgrids; they are interconnected by matching the input and output states of the network and converters. Virtual resistors have been widely used in existing models to generate a voltage for state-space models of the network that require voltage inputs. This paper accurately quantifies the adverse impacts of adding the virtual resistance and proposes an alternative method for network modelling that eliminates the requirement of the virtual resistor when interfacing converters with microgrids. The proposed nonlinear method allows initialization, time-domain simulations of the nonlinear model, and linearization and eigenvalue generation. A numerically linearized small-signal model is used to generate eigenvalues and is compared with the eigenvalues generated using the existing modelling method with virtual resistances. Deficiencies of the existing method and improvements offered by the proposed modelling method are clearly quantified. Electromagnetic transient (EMT) simulations using detailed switching models are used for validation of the proposed modelling method.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 2","pages":"584-596"},"PeriodicalIF":6.3,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10272358","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140291168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-04DOI: 10.35833/MPCE.2022.000845
Mina Haghighat;Mehdi Niroomand;Hossein Dehghani Tafti;Christopher D. Townsend;Tyrone Fernando
To maximize conversion efficiency, photovoltaic (PV) systems generally operate in the maximum power point tracking (MPPT) mode. However, due to the increasing penetration level of PV systems, there is a need for more developed control functions in terms of frequency support services and voltage control to maintain the reliability and stability of the power grid. Therefore, flexible active power control is a mandatory task for grid-connected PV systems to meet part of the grid requirements. Hence, a significant number of flexible power point tracking (FPPT) algorithms have been introduced in the existing literature. The purpose of such algorithms is to realize a cost-effective method to provide grid support functionalities while minimizing the reliance on energy storage systems. This paper provides a comprehensive overview of grid support functionalities that can be obtained with the FPPT control of PV systems such as frequency support and volt-var control. Each of these grid support functionalities necessitates PV systems to operate under one of the three control strategies, which can be provided with FPPT algorithms. The three control strategies are classified as: ① constant power generation control (CPGC), ② power reserve control (PRC), and ③ power ramp rate control (PRRC). A detailed discussion on available FPPT algorithms for each control strategy is also provided. This paper can serve as a comprehensive review of the state-of-the-art FPPT algorithms that can equip PV systems with various grid support functionalities.
{"title":"A Review of State-of-the-Art Flexible Power Point Tracking Algorithms in Photovoltaic Systems for Grid Support: Classification and Application","authors":"Mina Haghighat;Mehdi Niroomand;Hossein Dehghani Tafti;Christopher D. Townsend;Tyrone Fernando","doi":"10.35833/MPCE.2022.000845","DOIUrl":"https://doi.org/10.35833/MPCE.2022.000845","url":null,"abstract":"To maximize conversion efficiency, photovoltaic (PV) systems generally operate in the maximum power point tracking (MPPT) mode. However, due to the increasing penetration level of PV systems, there is a need for more developed control functions in terms of frequency support services and voltage control to maintain the reliability and stability of the power grid. Therefore, flexible active power control is a mandatory task for grid-connected PV systems to meet part of the grid requirements. Hence, a significant number of flexible power point tracking (FPPT) algorithms have been introduced in the existing literature. The purpose of such algorithms is to realize a cost-effective method to provide grid support functionalities while minimizing the reliance on energy storage systems. This paper provides a comprehensive overview of grid support functionalities that can be obtained with the FPPT control of PV systems such as frequency support and volt-var control. Each of these grid support functionalities necessitates PV systems to operate under one of the three control strategies, which can be provided with FPPT algorithms. The three control strategies are classified as: ① constant power generation control (CPGC), ② power reserve control (PRC), and ③ power ramp rate control (PRRC). A detailed discussion on available FPPT algorithms for each control strategy is also provided. This paper can serve as a comprehensive review of the state-of-the-art FPPT algorithms that can equip PV systems with various grid support functionalities.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 1","pages":"1-21"},"PeriodicalIF":6.3,"publicationDate":"2023-10-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10272357","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139572875","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-22DOI: 10.35833/MPCE.2022.000738
Chunyi Han;Lei Shang;Shi Su;Xuzhu Dong;Bo Wang;Hao Bai;Wei Li
This paper proposes a grid synchronization control strategy for the grid-connected voltage source converters (VSCs) based on the voltage dynamics of the DC-link capacitor in the VSC. The voltage dynamics of the DC-link capacitor are used to regulate the frequency and phase angle of the inner potential of the VSC, synchronizing the VSC with grid. Firstly, in the proposed strategy, the active power regulation and grid synchronization of the VSC are combined, which are separated in the traditional control strategy. This can avoid the instability of the VSC in a weak grid with a low short circuit ratio (SCR), aroused by the dynamic interaction between the separated control loops in traditional control strategies. Secondly, the energy stored in the DC-link capacitor is directly coupled with the grid via the inner potential of the VSC, and the inertia characteristic is naturally featured in the inner potential by the proposed strategy. With the increase of the capacitance, the natural inertial response of the VSC is helpful to improve the grid frequency dynamic. Finally, simulation results are presented to validate the correctness and effectiveness of the proposed strategy on the enhancement of the grid frequency and voltage dynamic support capability.
{"title":"Grid Synchronization Control for Grid-Connected Voltage Source Converters Based on Voltage Dynamics of DC-Link Capacitor","authors":"Chunyi Han;Lei Shang;Shi Su;Xuzhu Dong;Bo Wang;Hao Bai;Wei Li","doi":"10.35833/MPCE.2022.000738","DOIUrl":"https://doi.org/10.35833/MPCE.2022.000738","url":null,"abstract":"This paper proposes a grid synchronization control strategy for the grid-connected voltage source converters (VSCs) based on the voltage dynamics of the DC-link capacitor in the VSC. The voltage dynamics of the DC-link capacitor are used to regulate the frequency and phase angle of the inner potential of the VSC, synchronizing the VSC with grid. Firstly, in the proposed strategy, the active power regulation and grid synchronization of the VSC are combined, which are separated in the traditional control strategy. This can avoid the instability of the VSC in a weak grid with a low short circuit ratio (SCR), aroused by the dynamic interaction between the separated control loops in traditional control strategies. Secondly, the energy stored in the DC-link capacitor is directly coupled with the grid via the inner potential of the VSC, and the inertia characteristic is naturally featured in the inner potential by the proposed strategy. With the increase of the capacitance, the natural inertial response of the VSC is helpful to improve the grid frequency dynamic. Finally, simulation results are presented to validate the correctness and effectiveness of the proposed strategy on the enhancement of the grid frequency and voltage dynamic support capability.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 5","pages":"1678-1689"},"PeriodicalIF":5.7,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10260254","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142328384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-22DOI: 10.35833/MPCE.2023.000093
Yang Wang;Fei Xia;Ying Wang;Xianyong Xiao
This study presents a harmonic transfer function (HTF) based single-input single-output (SISO) impedance modeling method. The method converts an HTF from phase domain to sequence domain and then transforms it into an SISO impedance while preserving the frequency coupling information of different sequences and different harmonics. Applications of this method to a line-commutated converter based high-voltage direct current (LCC-HVDC) system are presented. The results demonstrate the accuracy of the derived SISO impedance, and a truncation-order selection is suggested. The case study shows that the proposed method facilitates simpler impedance measurements and associated stability analysis.
{"title":"Harmonic Transfer Function Based Single-Input Single-Output Impedance Modeling of LCC-HVDC Systems","authors":"Yang Wang;Fei Xia;Ying Wang;Xianyong Xiao","doi":"10.35833/MPCE.2023.000093","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000093","url":null,"abstract":"This study presents a harmonic transfer function (HTF) based single-input single-output (SISO) impedance modeling method. The method converts an HTF from phase domain to sequence domain and then transforms it into an SISO impedance while preserving the frequency coupling information of different sequences and different harmonics. Applications of this method to a line-commutated converter based high-voltage direct current (LCC-HVDC) system are presented. The results demonstrate the accuracy of the derived SISO impedance, and a truncation-order selection is suggested. The case study shows that the proposed method facilitates simpler impedance measurements and associated stability analysis.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 4","pages":"1327-1332"},"PeriodicalIF":5.7,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10260255","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141965083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-09-19DOI: 10.35833/MPCE.2023.000183
Yuqing Bao;Zhonghui Zuo;Xuehua Wu
Electrical water heaters (EWHs) are important candidates to provide demand-response services. The traditional optimization method for EWHs focuses on the optimization of the electricity consumption, without considering the shifting potential of the water-use activities. This paper proposes an optimization method for EWHs considering the shifting potentials of both the electricity consumption and water-use activities. Considering that the water-use activities could be monolithically shifted, the shifting model of the water-use activities was developed. In addition to the thermodynamic model of the EWH, the optimal scheduling model of the EWH was developed and solved using mixed-integer linear programming. Case studies were performed on a single EWH and aggregate EWHs, demonstrating that the proposed method can shift the water-use activities and therefore increase the load-shifting potential of the EWHs.
{"title":"Optimization Method for Electrical Water Heaters Considering Shifting Potentials of Electricity Consumption and Water-Use Activities","authors":"Yuqing Bao;Zhonghui Zuo;Xuehua Wu","doi":"10.35833/MPCE.2023.000183","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000183","url":null,"abstract":"Electrical water heaters (EWHs) are important candidates to provide demand-response services. The traditional optimization method for EWHs focuses on the optimization of the electricity consumption, without considering the shifting potential of the water-use activities. This paper proposes an optimization method for EWHs considering the shifting potentials of both the electricity consumption and water-use activities. Considering that the water-use activities could be monolithically shifted, the shifting model of the water-use activities was developed. In addition to the thermodynamic model of the EWH, the optimal scheduling model of the EWH was developed and solved using mixed-integer linear programming. Case studies were performed on a single EWH and aggregate EWHs, demonstrating that the proposed method can shift the water-use activities and therefore increase the load-shifting potential of the EWHs.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 4","pages":"1250-1259"},"PeriodicalIF":5.7,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10255429","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141965858","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
With the increasing wind power penetration in the power system, the auxiliary frequency control (AFC) of wind farm (WF) has been widely used. The traditional system frequency response (SFR) model is not suitable for the wind power generation system due to its poor accuracy and applicability. In this paper, a piecewise reduced-order frequency response (P-ROFR) model is proposed, and an optimized auxiliary frequency control (O-AFC) scheme of WF based on the P-ROFR model is proposed. Firstly, a full-order frequency response model considering the change in operating point of wind turbine is established to improve the applicability. In order to simplify the full-order model, a P-ROFR model with second-order structure and high accuracy at each frequency response stage is proposed. Based on the proposed P-ROFR model, the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed explicitly. Then, an O-AFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency regulation. Finally, the effectiveness of the proposed P-ROFR model and the performance of the proposed O-AFC scheme are verified by simulation studies.
{"title":"Optimized Auxiliary Frequency Control of Wind Farm Based on Piecewise Reduced-Order Frequency Response Model","authors":"Xu Zhang;Chen Zhao;Junchao Ma;Long Zhang;Dan Sun;Chenxu Wang;Yan Peng;Heng Nian","doi":"10.35833/MPCE.2023.000448","DOIUrl":"https://doi.org/10.35833/MPCE.2023.000448","url":null,"abstract":"With the increasing wind power penetration in the power system, the auxiliary frequency control (AFC) of wind farm (WF) has been widely used. The traditional system frequency response (SFR) model is not suitable for the wind power generation system due to its poor accuracy and applicability. In this paper, a piecewise reduced-order frequency response (P-ROFR) model is proposed, and an optimized auxiliary frequency control (O-AFC) scheme of WF based on the P-ROFR model is proposed. Firstly, a full-order frequency response model considering the change in operating point of wind turbine is established to improve the applicability. In order to simplify the full-order model, a P-ROFR model with second-order structure and high accuracy at each frequency response stage is proposed. Based on the proposed P-ROFR model, the relationship between the frequency response indexes and the auxiliary frequency controller coefficients is expressed explicitly. Then, an O-AFC scheme with the derived explicit expression as the optimization objective is proposed in order to improve the frequency support capability on the premise of ensuring the full release of the rotor kinetic energy and the full use of the effect of time delay on frequency regulation. Finally, the effectiveness of the proposed P-ROFR model and the performance of the proposed O-AFC scheme are verified by simulation studies.","PeriodicalId":51326,"journal":{"name":"Journal of Modern Power Systems and Clean Energy","volume":"12 3","pages":"791-802"},"PeriodicalIF":6.3,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10255430","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141091136","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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