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Ioannis Lestas - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Frequency Control With On–Off Load Side Participation in Power Networks
    IEEE Transactions on Control of Network Systems, 2020
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of decentralized secondary frequency regulation in power networks where ancillary services are provided via on–off load-Side Participation. We initially conSider on–off loads that switch when prescribed frequency thresholds are exceeded, together with a large class of passive continuous dynamics for generation and demand. The conSidered on–off loads are able to assist existing secondary frequency control mechanisms and return to their nominal operation when the power system is restored to its normal operation, a highly desirable feature that minimizes users’ disruption. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to chattering, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteretic on–off policy where loads switch on and off at different frequency thresholds and show that stability guarantees are retained when the same decentralized passivity conditions for continuous generation and demand hold. Several relevant examples are discussed to demonstrate the applicability of the proposed results. Furthermore, we verify our analytic results by using numerical investigations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Secondary frequency regulation in power networks with on-off load Side Participation
    2017 IEEE 56th Annual Conference on Decision and Control (CDC), 2017
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of secondary frequency regulation where ancillary services are provided via load-Side Participation. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to Zeno-like behavior, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteresis on-off policy and provide stability guarantees in this setting. We provide numerical investigations of the results on a realistic power network.

  • primary frequency regulation with load Side Participation part i stability and optimality
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Andreas Kasis, Eoin Devane, Chrysovalantis Spanias, Ioannis Lestas
    Abstract:

    We present a method to design distributed generation and demand control schemes for primary frequency regulation in power networks that guarantee asymptotic stability and ensure fairness of allocation. We impose a passivity condition on net power supply variables and provide explicit steady-state conditions on a general class of generation and demand control dynamics that ensure convergence of solutions to equilibria that solve an appropriately constructed network optimization problem. We also show that the inclusion of controllable demand results in a drop in steady-state frequency deviations. We discuss how various classes of dynamics used in recent studies fit within our framework and show that this allows for less conservative stability and optimality conditions. We illustrate our results with simulations on the IEEE 68-bus transmission system and the IEEE 37-bus distribution system with static and dynamic demand response schemes.

Andreas Kasis - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Frequency Control With On–Off Load Side Participation in Power Networks
    IEEE Transactions on Control of Network Systems, 2020
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of decentralized secondary frequency regulation in power networks where ancillary services are provided via on–off load-Side Participation. We initially conSider on–off loads that switch when prescribed frequency thresholds are exceeded, together with a large class of passive continuous dynamics for generation and demand. The conSidered on–off loads are able to assist existing secondary frequency control mechanisms and return to their nominal operation when the power system is restored to its normal operation, a highly desirable feature that minimizes users’ disruption. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to chattering, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteretic on–off policy where loads switch on and off at different frequency thresholds and show that stability guarantees are retained when the same decentralized passivity conditions for continuous generation and demand hold. Several relevant examples are discussed to demonstrate the applicability of the proposed results. Furthermore, we verify our analytic results by using numerical investigations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Secondary frequency regulation in power networks with on-off load Side Participation
    2017 IEEE 56th Annual Conference on Decision and Control (CDC), 2017
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of secondary frequency regulation where ancillary services are provided via load-Side Participation. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to Zeno-like behavior, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteresis on-off policy and provide stability guarantees in this setting. We provide numerical investigations of the results on a realistic power network.

  • primary frequency regulation with load Side Participation part i stability and optimality
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Andreas Kasis, Eoin Devane, Chrysovalantis Spanias, Ioannis Lestas
    Abstract:

    We present a method to design distributed generation and demand control schemes for primary frequency regulation in power networks that guarantee asymptotic stability and ensure fairness of allocation. We impose a passivity condition on net power supply variables and provide explicit steady-state conditions on a general class of generation and demand control dynamics that ensure convergence of solutions to equilibria that solve an appropriately constructed network optimization problem. We also show that the inclusion of controllable demand results in a drop in steady-state frequency deviations. We discuss how various classes of dynamics used in recent studies fit within our framework and show that this allows for less conservative stability and optimality conditions. We illustrate our results with simulations on the IEEE 68-bus transmission system and the IEEE 37-bus distribution system with static and dynamic demand response schemes.

Eoin Devane - One of the best experts on this subject based on the ideXlab platform.

  • primary frequency regulation with load Side Participation part i stability and optimality
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Andreas Kasis, Eoin Devane, Chrysovalantis Spanias, Ioannis Lestas
    Abstract:

    We present a method to design distributed generation and demand control schemes for primary frequency regulation in power networks that guarantee asymptotic stability and ensure fairness of allocation. We impose a passivity condition on net power supply variables and provide explicit steady-state conditions on a general class of generation and demand control dynamics that ensure convergence of solutions to equilibria that solve an appropriately constructed network optimization problem. We also show that the inclusion of controllable demand results in a drop in steady-state frequency deviations. We discuss how various classes of dynamics used in recent studies fit within our framework and show that this allows for less conservative stability and optimality conditions. We illustrate our results with simulations on the IEEE 68-bus transmission system and the IEEE 37-bus distribution system with static and dynamic demand response schemes.

  • primary frequency regulation with load Side Participation part ii beyond passivity approaches
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Eoin Devane, Andreas Kasis, Marina Antoniou, Ioannis Lestas
    Abstract:

    We conSider the problem of distributed generation and demand control for primary frequency regulation in power networks, such that stability and optimality of the power allocation can be guaranteed. It was shown in Part I of this work, that by imposing an input strict passivity condition on the net supply dynamics at each bus, combined with a decentralized condition on their steady-state behavior, convergence to optimality can be guaranteed for broad classes of generation and demand control dynamics in a general network. In this paper, we show that by taking into account additional local information, the input strict passivity condition can be relaxed to less restrictive decentralized conditions. These conditions extend the classes of generation and load dynamics for which convergence to optimality can be guaranteed beyond the class of passive systems, thus, allowing to reduce the conservatism in the analysis and feedback design.

  • primary frequency regulation in power networks with ancillary service from load Side Participation
    IFAC-PapersOnLine, 2017
    Co-Authors: Andreas Kasis, Eoin Devane, Ioannis Lestas
    Abstract:

    Abstract We conSider the problem of designing distributed generation and demand control schemes that provide ancillary service in primary frequency regulation in power networks such that stability and fairness in the power allocation can be guaranteed. It is desirable in such schemes that load Side Participation in frequency control is activated only when the frequency exceeds prescribed thresholds so as to avoid frequent intervention in the operation of loads. This, however, leads to nonlinear control schemes with vector fields with discontinuous derivatives. In this paper, we investigate how stability and optimality may be ensured when such dynamics are conSidered. We show that subgradient methods can be used to derive decentralised conditions that ensure optimality of the equilibrium points. Decentralised conditions for asymptotic stability that are valid in this context are also provided. We illustrate our results with simulations on the IEEE 68 bus system, where it is demonstrated that the inclusion of controllable loads offers improved transient behaviour and that an optimal power allocation among controllable loads is achieved.

  • Primary Frequency Regulation With Load-Side Participation—Part I: Stability and Optimality
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Andreas Kasis, Eoin Devane, Chrysovalantis Spanias, Ioannis Lestas
    Abstract:

    We present a method to design distributed generation and demand control schemes for primary frequency regulation in power networks that guarantee asymptotic stability and ensure fairness of allocation. We impose a passivity condition on net power supply variables and provide explicit steady-state conditions on a general class of generation and demand control dynamics that ensure convergence of solutions to equilibria that solve an appropriately constructed network optimization problem. We also show that the inclusion of controllable demand results in a drop in steady-state frequency deviations. We discuss how various classes of dynamics used in recent studies fit within our framework and show that this allows for less conservative stability and optimality conditions. We illustrate our results with simulations on the IEEE 68-bus transmission system and the IEEE 37-bus distribution system with static and dynamic demand response schemes.

  • Primary Frequency Regulation With Load-Side Participation—Part II: Beyond Passivity Approaches
    IEEE Transactions on Power Systems, 2017
    Co-Authors: Eoin Devane, Andreas Kasis, Marina Antoniou, Ioannis Lestas
    Abstract:

    We conSider the problem of distributed generation and demand control for primary frequency regulation in power networks, such that stability and optimality of the power allocation can be guaranteed. It was shown in Part I of this work, that by imposing an input strict passivity condition on the net supply dynamics at each bus, combined with a decentralized condition on their steady-state behavior, convergence to optimality can be guaranteed for broad classes of generation and demand control dynamics in a general network. In this paper, we show that by taking into account additional local information, the input strict passivity condition can be relaxed to less restrictive decentralized conditions. These conditions extend the classes of generation and load dynamics for which convergence to optimality can be guaranteed beyond the class of passive systems, thus, allowing to reduce the conservatism in the analysis and feedback design.

Nima Monshizadeh - One of the best experts on this subject based on the ideXlab platform.

  • Secondary Frequency Control With On–Off Load Side Participation in Power Networks
    IEEE Transactions on Control of Network Systems, 2020
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of decentralized secondary frequency regulation in power networks where ancillary services are provided via on–off load-Side Participation. We initially conSider on–off loads that switch when prescribed frequency thresholds are exceeded, together with a large class of passive continuous dynamics for generation and demand. The conSidered on–off loads are able to assist existing secondary frequency control mechanisms and return to their nominal operation when the power system is restored to its normal operation, a highly desirable feature that minimizes users’ disruption. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to chattering, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteretic on–off policy where loads switch on and off at different frequency thresholds and show that stability guarantees are retained when the same decentralized passivity conditions for continuous generation and demand hold. Several relevant examples are discussed to demonstrate the applicability of the proposed results. Furthermore, we verify our analytic results by using numerical investigations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • Stability of Primary Frequency Control with on-Off Load Side Participation in Power Networks
    2018 IEEE Conference on Decision and Control (CDC), 2018
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We conSider the problem of load Side Participation providing ancillary services to the power network within the primary frequency control timeframe. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing primary frequency control mechanisms. However, such control policies are prone to chattering, which limits their practicality. To resolve this issue, we propose loads that follow a hysteretic on-off policy, and show that chattering behavior is not observed within such setting. Furthermore, we provide design conditions that ensure the existence of equilibria when such loads are implemented. However, as numerical simulations demonstrate, hysteretic loads may exhibit limit cycle behavior, which is undesirable. This is resolved by proposing a novel control scheme for hystertic loads. For the latter scheme, we provide asymptotic stability guarantees and show that no limit cycle or chattering will be exhibited. The practicality of our analytic results is demonstrated with numerical simulations on the Northeast Power Coordinating Council (NPCC) 140-bus system.

  • CDC - Secondary frequency regulation in power networks with on-off load Side Participation
    2017 IEEE 56th Annual Conference on Decision and Control (CDC), 2017
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of secondary frequency regulation where ancillary services are provided via load-Side Participation. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to Zeno-like behavior, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteresis on-off policy and provide stability guarantees in this setting. We provide numerical investigations of the results on a realistic power network.

  • secondary frequency control with on off load Side Participation in power networks
    arXiv: Optimization and Control, 2017
    Co-Authors: Andreas Kasis, Nima Monshizadeh, Ioannis Lestas
    Abstract:

    We study the problem of secondary frequency regulation where ancillary services are provided via load-Side Participation. In particular, we conSider on-off loads that switch when prescribed frequency thresholds are exceeded in order to assist existing secondary frequency control mechanisms. We show that system stability is not compromised despite the switching nature of the loads. However, such control policies are prone to Zeno-like behavior, which limits the practicality of these schemes. As a remedy to this problem, we propose a hysteretic on-off policy where loads switch on and off at different frequency thresholds. Moreover, we show that by exploiting appropriate decentralized passivity conditions, stability guarantees for a power network with hysteretic loads can be provided. Several relevant examples are discussed to demonstrate the applicability of the proposed results. Furthermore, numerical investigations of the results are provided on the Northeast Power Coordinating Council (NPCC) 140-bus system.

David J. Hill - One of the best experts on this subject based on the ideXlab platform.

  • MPC-Based Frequency Control With Demand-Side Participation: A Case Study in an Isolated Wind-Aluminum Power System
    IEEE Transactions on Power Systems, 2015
    Co-Authors: Hao Jiang, Yonghua Song, David J. Hill
    Abstract:

    Aluminum production relies on the smelting process which consumes huge amounts of electrical energy. One possible solution to reduce the fossil fuel consumption by aluminum production is the integration of wind power. Based on this background, this paper studies an isolated power system for aluminum smelting production with a high penetration of wind power. A dynamic model of the aluminum smelter load (ASL) is introduced in this paper using the field experiment data. Based on this model, the dynamic model of the isolated system conSidering demand Side Participation is proposed. The MPC-based frequency controller is proposed to keep the frequency deviation within a proper range ( ±0.1 Hz) under wind power fluctuation as well as to recover the system frequency after a large disturbance (such as one generator trip). Finally, simulation results demonstrate the effectiveness of the proposed MPC based frequency controller.