The Experts below are selected from a list of 57 Experts worldwide ranked by ideXlab platform

Christopher L Demarco - One of the best experts on this subject based on the ideXlab platform.

  • convex relaxation of sparse tableau formulation for the ac optimal Power flow
    Electric Power Systems Research, 2019
    Co-Authors: Byungkwon Park, Christopher L Demarco
    Abstract:

    Abstract Optimal Power flow (OPF) approaches employing such methods as semi-definite programming (SDP) have garnered considerable interest in the literature of the last decade. The OPF formulations for these approaches have almost universally relied on Ybus admittance matrix representations, which derive from nodal analysis, and restrict allowable network elements to be voltage-controlled only. Limitations of nodal analysis long been recognized, and to overcome these, Commercial Power System software often employs modified nodal analysis (MNA). Here, we consider a novel general Power System modeling approach based on multi-port representation of individual components with Sparse Tableau Formulation (STF) of network constraints, which is more versatile than MNA for OPF requiring many monitored links with constrained flows. In STF, one is better able to exploit the fact that the vast majority of Power grid network elements have voltage-current behavior that is well-modeled as linear. This opens the door to simple, engineering-based convex relaxations. We discuss two relaxations, admittance-based and current-based. The tightness of the relaxation is shown to improve when angle constraints and narrow bounds for active Power generation are provided. Sequential bound tightening and reduced spatial branch-and-bound are discussed to obtain stronger relaxation solution. We conduct case studies to show the effectiveness of our relaxations with standard test cases.

  • sparse tableau relaxation for the optimal Power flow problem
    Allerton Conference on Communication Control and Computing, 2017
    Co-Authors: Byungkwon Park, Christopher L Demarco
    Abstract:

    Optimal Power flow (OPF) approaches employing such methods as semi-definite programming have garnered considerable interest in the literature of the last decade. The OPF formulations for these approaches have almost universally relied on Y bus admittance matrix representations, which derive from nodal analysis, and restrict allowable network elements to be voltage-controlled only. Limitations of nodal analysis long been recognized, and to overcome these, Commercial Power System software often employs modified nodal analysis (MNA). However, with OPF requiring many monitored links with constrained flows, the work here argues for a formulation even more versatile than MNA: Sparse Tableau Formulation (STF) of network constraints, with multi-port representation of individual components. The vast majority of transmission network components (e.g., transmission lines, transformers) have multi-port voltage-current behavior that is well-modelled as linear. Therefore, nonlinearities appear only in equations associated with generation and load at each bus. Utilizing STF, these sources of nonconvexity are confined to constraints local to each bus. This opens the door to simple, engineering-based convex relaxations. We introduce a constant current source at each bus, with these sources' values bounded in a manner that contains any feasible current produced by the actual generator or load model. The tightness of the relaxation is shown to improve when angle constraints are provided, and a DCOPF-based heuristic method is proposed to obtain such angle bounds.

Mahesh S Illindala - One of the best experts on this subject based on the ideXlab platform.

  • the influence of inverter based dgs and their controllers on distribution network protection
    IEEE Transactions on Industry Applications, 2014
    Co-Authors: Mohammed A Hajahmed, Mahesh S Illindala
    Abstract:

    The ever growing penetration of distributed generation (DG) in a distribution network has a profound impact on network protection and stability. Traditional protection schemes and algorithms need to be extensively investigated as more and more DGs get introduced into the network. The current version of IEEE Standard 1547 does not present a comprehensive solution for fault current detection in the presence of various kinds of DGs. Power electronic inverter-based DGs (IBDGs) are of special concern in distribution network protection as they are often incapable of providing sufficient fault current and their controllers play a principal role in the DG behavior. In this paper, the effects of voltage and current controllers for IBDGs on industrial and Commercial Power System protection schemes are investigated. It is shown that the inverter control mode has a direct impact on its fault current levels and duration. A simplified distribution network model with IBDG operating under voltage and current control modes was tested to verify the effects of these controllers. This paper also proposes an adaptive relaying algorithm to detect the faults in the presence of IBDGs with various types of controllers.

  • the influence of inverter based dgs and their controllers on distribution network protection
    IEEE Industry Applications Society Annual Meeting, 2013
    Co-Authors: Mohammed A Hajahmed, Mahesh S Illindala
    Abstract:

    The ever growing penetration of distributed generation (DG) in a distribution network has a profound impact on the network protection and stability. Traditional protection schemes and algorithms need to be extensively investigated as more and more DGs get introduced into the network. The current version of IEEE Std 1547 does not present a comprehensive solution for fault current detection in the presence of various kinds of DGs. Power electronic inverter-based DGs are of special concern in distribution network protection as they are often incapable of providing sufficient fault current and their controllers play a principal role in the DG behavior. In this paper, the effects of voltage and current controllers for inverter-based DGs on industrial and Commercial Power System distribution network protection schemes are investigated. It is shown that the type of controller and its design parameters during the fault have a direct impact on fault current levels and duration. A simplified distribution network model with inverter-based DG operating under voltage and current control modes was tested to verify the effects of these controllers. This paper also proposes an adaptive relaying algorithm to detect the faults in the presence of inverter-based DGs with various types of controllers.

Byungkwon Park - One of the best experts on this subject based on the ideXlab platform.

  • convex relaxation of sparse tableau formulation for the ac optimal Power flow
    Electric Power Systems Research, 2019
    Co-Authors: Byungkwon Park, Christopher L Demarco
    Abstract:

    Abstract Optimal Power flow (OPF) approaches employing such methods as semi-definite programming (SDP) have garnered considerable interest in the literature of the last decade. The OPF formulations for these approaches have almost universally relied on Ybus admittance matrix representations, which derive from nodal analysis, and restrict allowable network elements to be voltage-controlled only. Limitations of nodal analysis long been recognized, and to overcome these, Commercial Power System software often employs modified nodal analysis (MNA). Here, we consider a novel general Power System modeling approach based on multi-port representation of individual components with Sparse Tableau Formulation (STF) of network constraints, which is more versatile than MNA for OPF requiring many monitored links with constrained flows. In STF, one is better able to exploit the fact that the vast majority of Power grid network elements have voltage-current behavior that is well-modeled as linear. This opens the door to simple, engineering-based convex relaxations. We discuss two relaxations, admittance-based and current-based. The tightness of the relaxation is shown to improve when angle constraints and narrow bounds for active Power generation are provided. Sequential bound tightening and reduced spatial branch-and-bound are discussed to obtain stronger relaxation solution. We conduct case studies to show the effectiveness of our relaxations with standard test cases.

  • sparse tableau relaxation for the optimal Power flow problem
    Allerton Conference on Communication Control and Computing, 2017
    Co-Authors: Byungkwon Park, Christopher L Demarco
    Abstract:

    Optimal Power flow (OPF) approaches employing such methods as semi-definite programming have garnered considerable interest in the literature of the last decade. The OPF formulations for these approaches have almost universally relied on Y bus admittance matrix representations, which derive from nodal analysis, and restrict allowable network elements to be voltage-controlled only. Limitations of nodal analysis long been recognized, and to overcome these, Commercial Power System software often employs modified nodal analysis (MNA). However, with OPF requiring many monitored links with constrained flows, the work here argues for a formulation even more versatile than MNA: Sparse Tableau Formulation (STF) of network constraints, with multi-port representation of individual components. The vast majority of transmission network components (e.g., transmission lines, transformers) have multi-port voltage-current behavior that is well-modelled as linear. Therefore, nonlinearities appear only in equations associated with generation and load at each bus. Utilizing STF, these sources of nonconvexity are confined to constraints local to each bus. This opens the door to simple, engineering-based convex relaxations. We introduce a constant current source at each bus, with these sources' values bounded in a manner that contains any feasible current produced by the actual generator or load model. The tightness of the relaxation is shown to improve when angle constraints are provided, and a DCOPF-based heuristic method is proposed to obtain such angle bounds.

Mohammed A Hajahmed - One of the best experts on this subject based on the ideXlab platform.

  • the influence of inverter based dgs and their controllers on distribution network protection
    IEEE Transactions on Industry Applications, 2014
    Co-Authors: Mohammed A Hajahmed, Mahesh S Illindala
    Abstract:

    The ever growing penetration of distributed generation (DG) in a distribution network has a profound impact on network protection and stability. Traditional protection schemes and algorithms need to be extensively investigated as more and more DGs get introduced into the network. The current version of IEEE Standard 1547 does not present a comprehensive solution for fault current detection in the presence of various kinds of DGs. Power electronic inverter-based DGs (IBDGs) are of special concern in distribution network protection as they are often incapable of providing sufficient fault current and their controllers play a principal role in the DG behavior. In this paper, the effects of voltage and current controllers for IBDGs on industrial and Commercial Power System protection schemes are investigated. It is shown that the inverter control mode has a direct impact on its fault current levels and duration. A simplified distribution network model with IBDG operating under voltage and current control modes was tested to verify the effects of these controllers. This paper also proposes an adaptive relaying algorithm to detect the faults in the presence of IBDGs with various types of controllers.

  • the influence of inverter based dgs and their controllers on distribution network protection
    IEEE Industry Applications Society Annual Meeting, 2013
    Co-Authors: Mohammed A Hajahmed, Mahesh S Illindala
    Abstract:

    The ever growing penetration of distributed generation (DG) in a distribution network has a profound impact on the network protection and stability. Traditional protection schemes and algorithms need to be extensively investigated as more and more DGs get introduced into the network. The current version of IEEE Std 1547 does not present a comprehensive solution for fault current detection in the presence of various kinds of DGs. Power electronic inverter-based DGs are of special concern in distribution network protection as they are often incapable of providing sufficient fault current and their controllers play a principal role in the DG behavior. In this paper, the effects of voltage and current controllers for inverter-based DGs on industrial and Commercial Power System distribution network protection schemes are investigated. It is shown that the type of controller and its design parameters during the fault have a direct impact on fault current levels and duration. A simplified distribution network model with inverter-based DG operating under voltage and current control modes was tested to verify the effects of these controllers. This paper also proposes an adaptive relaying algorithm to detect the faults in the presence of inverter-based DGs with various types of controllers.

Shunsuke Nishi - One of the best experts on this subject based on the ideXlab platform.