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Ronald Gordon Harley - One of the best experts on this subject based on the ideXlab platform.

  • two level dynamic stochastic optimal Power Flow Control for Power systems with intermittent renewable generation
    IEEE Transactions on Power Systems, 2013
    Co-Authors: Jiaqi Liang, G K Venayagamoorthy, Diogenes Molina, Ronald Gordon Harley
    Abstract:

    High penetration of intermittent renewable energy imposes new challenges to the operation and Control of Power systems. Power system security needs to be ensured dynamically as the system operating condition continuously changes. The dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the Adaptive Critic Designs (ACDs) has shown promising dynamic Power Flow Control capability and has been demonstrated in a small system. To further investigate the potential of the DSOPF Control algorithm for large Power systems, a 70-bus test Power system with different generation resources, including large wind plants, is developed. A two-level DSOPF Control scheme is proposed in this paper to scale up the DSOPF algorithm for this 70-bus system. The lower-level area DSOPF Controllers Control their own area Power network. The top-level global DSOPF Controller coordinates the area Controllers by adjusting the inter-area tie-line Flows. This two-level architecture distributes the Control and computation burden to multiple area DSOPF Controllers, and reduces the training difficulty for implementing the DSOPF Control for a large Power network. Simulation studies on the 70-bus Power system with large wind variation are shown to demonstrate the effectiveness of the proposed two-level DSOPF Control scheme.

  • wide area measurement based dynamic stochastic optimal Power Flow Control for smart grids with high variability and uncertainty
    Power and Energy Society General Meeting, 2012
    Co-Authors: Jiaqi Liang, G K Venayagamoorthy, Ronald Gordon Harley
    Abstract:

    Summary form only given. To achieve a high penetration level of intermittent renewable energy, the operation and Control of Power systems need to account for the associated high variability and uncertainty. Power system stability and security need to be ensured dynamically as the system operating condition continuously changes. A wide-area measurement based dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the adaptive critic designs (ACDs) is presented in this paper. The proposed DSOPF Control replaces the traditional AGC and secondary voltage Control, and provides a coordinated AC Power Flow Control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal Control, where the Control objective is explicitly formulated to incorporate Power system economy, stability and security considerations. The proposed DSOPF Controller dynamically drives the Power system to its optimal operating point by continuously adjusting the steady-state set points sent by the traditional OPF algorithm. A 12-bus test Power system is used to demonstrate the development and effectiveness of the proposed DSOPF Controller.

  • Wide-area measurement based dynamic stochastic optimal Power Flow Control for smart grids with high variability and uncertainty
    IEEE Transactions on Smart Grid, 2012
    Co-Authors: Jiaqi Liang, Ronald Gordon Harley
    Abstract:

    To achieve a high penetration level of intermittent renewable energy, the operation and Control of Power systems need to account for the associated high variability and uncertainty. Power system stability and security need to be ensured dynamically as the system operating condition continuously changes. A wide-area measurement based dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the adaptive critic designs (ACDs) is presented in this paper. The proposed DSOPF Control replaces the traditional AGC and secondary voltage Control, and provides a coordinated AC Power Flow Control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal Control, where the Control objective is explicitly formulated to incorporate Power system economy, stability and security considerations. The proposed DSOPF Controller dynamically drives the Power system to its optimal operating point by continuously adjusting the steady-state set points sent by the traditional OPF algorithm. A 12-bus test Power system is used to demonstrate the development and effectiveness of the proposed DSOPF Controller.

Jiaqi Liang - One of the best experts on this subject based on the ideXlab platform.

  • two level dynamic stochastic optimal Power Flow Control for Power systems with intermittent renewable generation
    IEEE Transactions on Power Systems, 2013
    Co-Authors: Jiaqi Liang, G K Venayagamoorthy, Diogenes Molina, Ronald Gordon Harley
    Abstract:

    High penetration of intermittent renewable energy imposes new challenges to the operation and Control of Power systems. Power system security needs to be ensured dynamically as the system operating condition continuously changes. The dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the Adaptive Critic Designs (ACDs) has shown promising dynamic Power Flow Control capability and has been demonstrated in a small system. To further investigate the potential of the DSOPF Control algorithm for large Power systems, a 70-bus test Power system with different generation resources, including large wind plants, is developed. A two-level DSOPF Control scheme is proposed in this paper to scale up the DSOPF algorithm for this 70-bus system. The lower-level area DSOPF Controllers Control their own area Power network. The top-level global DSOPF Controller coordinates the area Controllers by adjusting the inter-area tie-line Flows. This two-level architecture distributes the Control and computation burden to multiple area DSOPF Controllers, and reduces the training difficulty for implementing the DSOPF Control for a large Power network. Simulation studies on the 70-bus Power system with large wind variation are shown to demonstrate the effectiveness of the proposed two-level DSOPF Control scheme.

  • wide area measurement based dynamic stochastic optimal Power Flow Control for smart grids with high variability and uncertainty
    Power and Energy Society General Meeting, 2012
    Co-Authors: Jiaqi Liang, G K Venayagamoorthy, Ronald Gordon Harley
    Abstract:

    Summary form only given. To achieve a high penetration level of intermittent renewable energy, the operation and Control of Power systems need to account for the associated high variability and uncertainty. Power system stability and security need to be ensured dynamically as the system operating condition continuously changes. A wide-area measurement based dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the adaptive critic designs (ACDs) is presented in this paper. The proposed DSOPF Control replaces the traditional AGC and secondary voltage Control, and provides a coordinated AC Power Flow Control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal Control, where the Control objective is explicitly formulated to incorporate Power system economy, stability and security considerations. The proposed DSOPF Controller dynamically drives the Power system to its optimal operating point by continuously adjusting the steady-state set points sent by the traditional OPF algorithm. A 12-bus test Power system is used to demonstrate the development and effectiveness of the proposed DSOPF Controller.

  • Wide-area measurement based dynamic stochastic optimal Power Flow Control for smart grids with high variability and uncertainty
    IEEE Transactions on Smart Grid, 2012
    Co-Authors: Jiaqi Liang, Ronald Gordon Harley
    Abstract:

    To achieve a high penetration level of intermittent renewable energy, the operation and Control of Power systems need to account for the associated high variability and uncertainty. Power system stability and security need to be ensured dynamically as the system operating condition continuously changes. A wide-area measurement based dynamic stochastic optimal Power Flow (DSOPF) Control algorithm using the adaptive critic designs (ACDs) is presented in this paper. The proposed DSOPF Control replaces the traditional AGC and secondary voltage Control, and provides a coordinated AC Power Flow Control solution to the smart grid operation in an environment with high short-term uncertainty and variability. The ACD technique, specifically the dual heuristic dynamic programming (DHP), is used to provide nonlinear optimal Control, where the Control objective is explicitly formulated to incorporate Power system economy, stability and security considerations. The proposed DSOPF Controller dynamically drives the Power system to its optimal operating point by continuously adjusting the steady-state set points sent by the traditional OPF algorithm. A 12-bus test Power system is used to demonstrate the development and effectiveness of the proposed DSOPF Controller.

Zhe Chen - One of the best experts on this subject based on the ideXlab platform.

  • Power Flow Control for transmission networks with implicit modeling of static synchronous series compensator
    International Journal of Electrical Power & Energy Systems, 2015
    Co-Authors: Francisco Jurado, Salah Kamel, Zhe Chen
    Abstract:

    Abstract This paper presents an implicit modeling of Static Synchronous Series Compensator (SSSC) in Newton–Raphson load Flow method. The algorithm of load Flow is based on the revised current injection formulation. The developed model of SSSC is depended on the current injection approach. In this model, the voltage source representation of SSSC is transformed to current source, and then this current is injected at the sending and auxiliary buses. These injected currents at the terminals of SSSC are a function of the required line Flow and voltage of buses. These currents can be included easily to the original mismatches at the terminal buses of SSSC. The developed model can be used to Control active and reactive line Flow together or individually. The implicit modeling of SSSC device decreases the complexity of load Flow code, the modification of Jacobian matrix is avoided, the change only will be in the mismatches vector. Finally, this modeling solves the problem that happens when the SSSC is only connected between two areas. Numerical examples on the WSCC 9-bus, IEEE 30-bus system, and IEEE 118-bus system are used to illustrate the feasibility of the developed SSSC model and performance of the Newton–Raphson current injection load Flow algorithm.

  • dynamic stability enhancement and Power Flow Control of a hybrid wind and marine current farm using smes
    IEEE Transactions on Energy Conversion, 2009
    Co-Authors: Li Wang, Shiangshong Chen, Zhe Chen
    Abstract:

    This paper presents a Control scheme based on a superconducting magnetic energy storage (SMES) unit to achieve both Power Flow Control and damping enhancement of a novel hybrid wind and marine-current farm (MCF) connected to a large Power grid. The performance of the studied wind farm (WF) is simulated by an equivalent 80-MW induction generator (IG) while an equivalent 60-MW IG is employed to simulate the characteristics of the MCF. A damping Controller for the SMES unit is designed by using modal Control theory to contribute effective damping characteristics to the studied combined WF and MCF under different operating conditions. A frequency-domain approach based on a linearized system model using eigen techniques and a time-domain scheme based on a nonlinear system model subject to disturbance conditions are both employed to validate the effectiveness of the proposed Control scheme. It can be concluded from the simulated results that the proposed SMES unit combined with the designed damping Controller is very effective to stabilize the studied combined WF and MCF under various wind speeds. The inherent fluctuations of the injected active Power and reactive Power of the WF and MCF to the Power grid can also be effectively Controlled by the proposed Control scheme.

  • Power Flow Control and damping enhancement of a large wind farm using a superconducting magnetic energy storage unit
    Iet Renewable Power Generation, 2009
    Co-Authors: Shiangshong Chen, Lingfeng Wang, Weijen Lee, Zhe Chen
    Abstract:

    A novel scheme using a superconducting magnetic energy storage (SMES) unit to perform both Power Flow Control and damping enhancement of a large wind farm (WF) feeding to a utility grid is presented. The studied WF consisting of forty 2 MW wind induction generators (IGs) is simulated by an equivalent 80 MW IG. A damping Controller of the SMES unit is designed based on the modal Control theory to contribute proper damping characteristics to the studied WF under different wind speeds. A frequency-domain approach based on a linearised system model using eigen techniques and a time-domain scheme based on a nonlinear system model subject to disturbance conditions are both employed to validate the effectiveness of the proposed SMES unit with the designed SMES damping Controller. It can be concluded from the simulated results that the proposed SMES unit combined with the designed damping Controller is very effective in stabilising the studied large WF under various wind speeds. The inherent fluctuations of the injected active Power of the WF to the Power grid can also be effectively Controlled by the proposed Control scheme.

Marco Liserre - One of the best experts on this subject based on the ideXlab platform.

  • grid forming Control of smart solid state transformer in meshed network
    International Symposium on Power Electronics for Distributed Generation Systems, 2021
    Co-Authors: Rongwu Zhu, Marco Liserre
    Abstract:

    Smart solid-state transformer (ST) is a promising solution to modernize the current electricity grid with high penetration of renewables, behaving as an energy hub/router. The ST-fed network can operate in either a radial or meshed configuration, due to the excellent Power Flow Control capability. The Power Flow Control scheme of ST is dependent on the ST-fed network configuration, (e.g., radial or meshed network), which is also impacted by the grid condition, i.e., grid faults. An universal Power Flow Control scheme to allow the ST operating in both radial network and meshed network can avoid the transition caused by switching the Control schemes. This paper proposes a grid forming Control for the ST to fulfill aforementioned requirements and to ensure the dynamic performances under step change of the Power setpoint. The simulation results based on the adapted Cigre LVac grid benchmark models are carried out in Matlab to validate the correctness of the proposed grid forming Control of ST.

  • reverse Power Flow Control in a st fed distribution grid
    IEEE Transactions on Smart Grid, 2018
    Co-Authors: Giovanni De Carne, Giampaolo Buticchi, Marco Liserre
    Abstract:

    The massive integration of distributed generation in the grid poses new challenges to the system operators, like the reverse Power Flow from the low voltage (LV) to medium voltage (MV) grid. In the case of high DG Power production and low load absorption, the voltage rises in the line reaching the upper voltage limit. At this regard the smart transformer (ST) offers a new possibility to limit the reverse Power Flow in the MV grids. The ST can adapt the voltage waveform modifying the frequency in order to interact with the local distributed generation, that are normally equipped with droop characteristic. However, when a fast change in the frequency is applied to avoid reverse Power Flow to MV grid, stability problems, so far not investigated, arise. In this paper, the stability analysis has been performed analytically and validated by means of Control-hardware-in-loop in a real time digital simulator and with experimental results in laboratory.

  • reactive Power Flow Control for pv inverters voltage support in lv distribution networks
    IEEE Transactions on Smart Grid, 2017
    Co-Authors: Angel Molinagarcia, Marco Liserre, R A Mastromauro, Tania Garciasanchez, Sante Pugliese, S Stasi
    Abstract:

    This paper proposes a reactive Power Flow Control pursuing the active integration of photovoltaic systems in LV distribution networks. An alternative Power Flow analysis is performed according to the specific characteristics of LV networks, such as high resistance/reactance ratio and radial topologies. The proposed solution gives high performances, in terms of rms-voltage regulation, by estimating the reactive Power reference on each node considering the influence of the rest of the nodes in terms of active and reactive Power demanded/generated by them. The local Control of each photovoltaic system is based on the Power converter Control, interfacing these units with the grid and the loads respectively. The local Control is designed on the basis of locally measured feedback variables. Photovoltaic units thus guarantee universal operation, being able to change between islanding-mode and grid-connected mode without disrupting critical loads connected to them, and allowing smooth transitions. Exhaustive results are also included and discussed in this paper.

  • reverse Power Flow Control in a st fed distribution grid
    European Conference on Cognitive Ergonomics, 2016
    Co-Authors: Giovanni De Carne, Giampaolo Buticchi, Marco Liserre
    Abstract:

    The increasing implementation of Distributed Generation (DG) in the distribution grids creates new challenges in Controlling the voltage profile. If the DG production exceeds the load consumption, the Power Flow reverses through the MV/LV substations. The reverse Power Flow impacts mainly on the voltage profile, increasing further the voltage in LV and MV grids. At this regard the Smart Transformer offers a new possibility to avoid the reverse Power Flow in the MV grids. The ST can adapt the voltage waveform modifying the frequency in order to interact with the local DG: the DG PLL notices the frequency change and the generators, equipped with droop Controllers, decrease their Power output. This paper deals specifically with the stability issues of the DG PLL when a fast change in the frequency is applied for avoiding the reverse Power Flow in MV grid. If the PLL in the DG is tuned with a low bandwidth, it could result in oscillatory phenomena in the current Controller of the DG. The evaluation of the stability analysis has been performed analytically and validated by means of Control-Hardware-In-Loop (CHIL).

Salah Kamel - One of the best experts on this subject based on the ideXlab platform.

  • Power Flow Control for transmission networks with implicit modeling of static synchronous series compensator
    International Journal of Electrical Power & Energy Systems, 2015
    Co-Authors: Francisco Jurado, Salah Kamel, Zhe Chen
    Abstract:

    Abstract This paper presents an implicit modeling of Static Synchronous Series Compensator (SSSC) in Newton–Raphson load Flow method. The algorithm of load Flow is based on the revised current injection formulation. The developed model of SSSC is depended on the current injection approach. In this model, the voltage source representation of SSSC is transformed to current source, and then this current is injected at the sending and auxiliary buses. These injected currents at the terminals of SSSC are a function of the required line Flow and voltage of buses. These currents can be included easily to the original mismatches at the terminal buses of SSSC. The developed model can be used to Control active and reactive line Flow together or individually. The implicit modeling of SSSC device decreases the complexity of load Flow code, the modification of Jacobian matrix is avoided, the change only will be in the mismatches vector. Finally, this modeling solves the problem that happens when the SSSC is only connected between two areas. Numerical examples on the WSCC 9-bus, IEEE 30-bus system, and IEEE 118-bus system are used to illustrate the feasibility of the developed SSSC model and performance of the Newton–Raphson current injection load Flow algorithm.