The Experts below are selected from a list of 768 Experts worldwide ranked by ideXlab platform

Luis Garcia De Vicuna - One of the best experts on this subject based on the ideXlab platform.

  • voltage support control strategies for Static Synchronous Compensators under unbalanced voltage sags
    IEEE Transactions on Industrial Electronics, 2014
    Co-Authors: Miguel Castilla, Jaume Miret, Antonio Camacho, J Matas, Luis Garcia De Vicuna
    Abstract:

    Static Synchronous Compensators have been broadly employed for the provision of electrical ac network services, which include voltage regulation, network balance, and stability improvement. Several studies of such Compensators have also been conducted to improve the ac network operation during unbalanced voltage sags. This paper presents a complete control scheme intended for Synchronous Compensators operating under these abnormal network conditions. In particular, this control scheme introduces two contributions: a novel reactive current reference generator and a new voltage support control loop. The current reference generator has as a main feature the capacity to supply the required reactive current even when the voltage drops in amplitude during the voltage sag. Thus, a safe system operation is easily guaranteed by fixing the limit required current to the maximum rated current. The voltage control loop is able to implement several control strategies by setting two voltage set points. In this paper, three voltage support control strategies are proposed, and their advantages and limitations are discussed in detail. The two theoretical contributions of this paper have been validated by experimental results. Certainly, the topic of voltage support is open for further research, and the control scheme proposed in this paper can be viewed as an interesting configuration to devise other control strategies in future works.

  • coordinated reactive power control for Static Synchronous Compensators under unbalanced voltage sags
    International Symposium on Industrial Electronics, 2012
    Co-Authors: Miguel Castilla, Jaume Miret, Antonio Camacho, J Matas, Eduardo Alarcongallo, Luis Garcia De Vicuna
    Abstract:

    Unbalanced voltage sags strongly deteriorate the performance of power converters and electrical machines connected to the distribution network. In particular, a reduction of the power quality is noticed in these equipments, which is caused by a ripple in the output power and an increase of the current harmonic distortion. Several solutions based on reactive power compensation have been introduced to cope with this problem. Among them, Static Synchronous Compensators have confirmed the superior performance due to the possibility of using all rated power exclusively to voltage support. This paper presents a simple reactive power control algorithm for Static Synchronous Compensators operating under unbalanced voltage sags. The main feature of the proposed algorithm is that it allows a fine adjustment of the amount of reactive power injected by the positive- and negative-sequence components. Thus the control algorithm provides voltage support at the output of the Static Synchronous compensator. Specifically the proposed control conveniently corrects both the positive- and negative-sequence voltage. Selected simulation results are provided to validate the proposal.

Mj Hossain - One of the best experts on this subject based on the ideXlab platform.

  • A commercial building based microgrid performance investigation
    'Springer Science and Business Media LLC', 2019
    Co-Authors: Liu J, Lu J, Mj Hossain, Li H
    Abstract:

    © Springer Nature Switzerland AG 2019. In order to overcome the problems which distributed generations bring to the power system, the microgrid concept is proposed. For the power quality consideration, the introduction of the Static Synchronous Compensators and the active power filters may lead to complexity and extra cost to the system. Therefore, an appropriate control strategy for the microgrid is developed in this paper to combine the power quality improvement function to the interlinking converter. This paper investigated the performance of a commercial building based microgrid system. The proposed control strategy enables the microgrid to achieve the active power, reactive power, and harmonics compensation functions. Different scenarios are carried out through simulation based on the real case data. The simulation results show that the microgrid performs effectively with the grid under different cases

  • agent based reactive power management of power distribution networks with distributed energy generation
    Energy Conversion and Management, 2016
    Co-Authors: M S Rahman, M A Mahmud, H R Pota, Mj Hossain
    Abstract:

    In this paper, a new agent-based distributed reactive power management scheme is proposed to improve the voltage stability of energy distribution systems with distributed generation units. Three types of agents – distribution system agent, estimator agent, and control agent are developed within the multi-agent framework. The agents simultaneously coordinated their activities through the online information and energy flow. The overall achievement of the proposed scheme depends on the coordination between two tasks – (i) estimation of reactive power using voltage variation formula and (ii) necessary control actions to provide the estimated reactive power to the distribution networks through the distributed Static Synchronous Compensators. A linear quadratic regulator with a proportional integrator is designed for the control agent in order to control the reactive component of the current and the DC voltage of the Compensators. The performance of the proposed scheme is tested on a 10-bus power distribution network under various scenarios. The effectiveness is validated by comparing the proposed approach to the conventional proportional integral control approach. It is found that, the agent-based scheme provides excellent robust performance under various operating conditions of the power distribution network.

  • distributed multi agent scheme for reactive power management with renewable energy
    Energy Conversion and Management, 2014
    Co-Authors: M S Rahman, M A Mahmud, H R Pota, Mj Hossain
    Abstract:

    This paper presents a new distributed multi-agent scheme for reactive power management in smart coordinated distribution networks with renewable energy sources (RESs) to enhance the dynamic voltage stability, which is mainly based on controlling distributed Static Synchronous Compensators (DSTATCOMs). The proposed control scheme is incorporated in a multi-agent framework where the intelligent agents simultaneously coordinate with each other and represent various physical models to provide information and energy flow among different physical processes. The reactive power is estimated from the topology of distribution networks and with this information, necessary control actions are performed through the proposed proportional integral (PI) controller. The performance of the proposed scheme is evaluated on a 8-bus distribution network under various operating conditions. The performance of the proposed scheme is validated through simulation results and these results are compared to that of conventional PI-based DSTATCOM control scheme. From simulation results, it is found that the distributed MAS provides excellence performance for improving voltage profiles by managing reactive power in a smarter way.

Subhashish Bhattacharya - One of the best experts on this subject based on the ideXlab platform.

  • a control structure for pwm controlled Static Synchronous Compensators under unbalanced conditions and grid faults
    International Journal of Electrical Power & Energy Systems, 2015
    Co-Authors: Saman Babaei, Subhashish Bhattacharya
    Abstract:

    Abstract Grid connected Voltage Source Converters (VSCs) are the heart of many applications with power quality concerns due to their reactive power controllability. Among the widely used grid-connected applications of the VSCs, the Static Synchronous Compensators (STATCOMs) are commonly used for compensating the voltage quality problems that come from voltage sag and swell. In spite of superior feature of fast voltage regulation and reactive power support functionality, VSC-based STATCOMs have the major drawback of being sensitive to the grid disturbances, especially the unbalanced condition and faults. Moreover, when the STATCOMs are used in the Distributed Generation (DG) applications or reactive power support of the sensitive industrial load, the unbalanced condition becomes even more intolerable. Protection system usually trips due to over current or highly distorted current caused by negative sequence current flow under unbalanced conditions and system faults. This paper propose an alternative control structure to keep the VSC-based STATCOM online during the unbalanced condition and system faults by limiting the negative sequence current. This eliminates the need to redesign/overdesign of the STACOM power components and over rating of the semiconductor switches to operate under fault current. Converter MVA rating reduction will decrease the cost significantly. Proposed controller performance has been verified by simulation and Hardware-In-the-Loop test.

  • dual angle control for line frequency switched Static Synchronous Compensators under system faults
    IEEE Transactions on Power Electronics, 2014
    Co-Authors: Saman Babaei, Babak Parkhideh, Mukul C Chandorkar, B Fardanesh, Subhashish Bhattacharya
    Abstract:

    Voltage-sourced converter (VSC)-based Static Synchronous Compensators (STATCOMs) are used for voltage regulation in transmission and distribution systems. Unlike PWM-controlled STATCOMs, angle-controlled STATCOMs are switched at line frequency to limit the system losses. In recent years, angle-controlled STATCOMs have been deployed by utilities for the purpose of transmission system voltage regulation, voltage stability improvement, and increasing operational functionality. Despite the superior feature on voltage waveform quality and efficiency, the practical angle-controlled STATCOMs suffer from the over-current (and trips) and possible saturation of the interfacing transformers caused by negative sequence current during unbalanced conditions and faults in the utility. This paper specifically proposes a control structure to improve the angle-controlled STATCOMs performance under unbalanced conditions and faults. The main improvement is a substantial decrease in the negative sequence current and dc-link voltage oscillations under power system faults by the proposed control. This eliminates the need to redesign the STACOM power components to operate under fault current and dc-link voltage oscillations. The proposed control structure is designed based on adding appropriate oscillations to the conventional angle-controller output that is the control angle by which the VSC voltage vector leads/lags the line voltage vector. Since this control structure uses two angles for controlling the VSC output voltage, it is called dual angle control (DAC). PSCAD/EMTDC and experimental results verify the validity of the proposed control structure under unbalanced system conditions and faults. The experiments were conducted on a transient network analyzer, a unique hardware-based flexible ac transmission system simulator which was designed to study system faults and transients for a 2 × 100 MVA STATCOM field installation.

  • oscillatory angle control scheme for pwm Static Synchronous Compensators under unbalanced conditions and system faults
    Energy Conversion Congress and Exposition, 2013
    Co-Authors: Saman Babaei, Subhashish Bhattacharya
    Abstract:

    Grid connected Voltage Source Converters (VSCs) are the heart of many applications with power quality concerns due to their reactive power controllability. Among the widely used grid-connected applications of the VSCs, the Static Synchronous Compensators (STATCOMs) are commonly used for compensating the voltage quality problems that come from voltage sag and swell. In spite of superior feature of fast voltage regulation and reactive power support functionality, VSC-based STATCOMs have the major drawback of being sensitive to the grid disturbances, especially the unbalanced condition and faults. Moreover, when the STATCOMs are used in the Distributed Generation (DG) applications or reactive power support of the sensitive industrial load, the unbalanced condition becomes even more intolerable. Protection system usually trips due to over current or highly distorted current caused by negative sequence current flow under unbalanced conditions and system faults. This paper propose an alternative control structure to keep the VSC-based STATCOM online during the unbalanced condition and system faults by limiting the negative sequence current. This eliminates the need to redesign/overdesign of the STACOM power components and over rating of the semiconductor switches to operate under fault current. Converter MVA rating reduction will decrease the cost significantly. Proposed controller performance has been verified by simulation and Hardware-In-the-Loop test.

Miguel Castilla - One of the best experts on this subject based on the ideXlab platform.

  • voltage support control strategies for Static Synchronous Compensators under unbalanced voltage sags
    IEEE Transactions on Industrial Electronics, 2014
    Co-Authors: Miguel Castilla, Jaume Miret, Antonio Camacho, J Matas, Luis Garcia De Vicuna
    Abstract:

    Static Synchronous Compensators have been broadly employed for the provision of electrical ac network services, which include voltage regulation, network balance, and stability improvement. Several studies of such Compensators have also been conducted to improve the ac network operation during unbalanced voltage sags. This paper presents a complete control scheme intended for Synchronous Compensators operating under these abnormal network conditions. In particular, this control scheme introduces two contributions: a novel reactive current reference generator and a new voltage support control loop. The current reference generator has as a main feature the capacity to supply the required reactive current even when the voltage drops in amplitude during the voltage sag. Thus, a safe system operation is easily guaranteed by fixing the limit required current to the maximum rated current. The voltage control loop is able to implement several control strategies by setting two voltage set points. In this paper, three voltage support control strategies are proposed, and their advantages and limitations are discussed in detail. The two theoretical contributions of this paper have been validated by experimental results. Certainly, the topic of voltage support is open for further research, and the control scheme proposed in this paper can be viewed as an interesting configuration to devise other control strategies in future works.

  • coordinated reactive power control for Static Synchronous Compensators under unbalanced voltage sags
    International Symposium on Industrial Electronics, 2012
    Co-Authors: Miguel Castilla, Jaume Miret, Antonio Camacho, J Matas, Eduardo Alarcongallo, Luis Garcia De Vicuna
    Abstract:

    Unbalanced voltage sags strongly deteriorate the performance of power converters and electrical machines connected to the distribution network. In particular, a reduction of the power quality is noticed in these equipments, which is caused by a ripple in the output power and an increase of the current harmonic distortion. Several solutions based on reactive power compensation have been introduced to cope with this problem. Among them, Static Synchronous Compensators have confirmed the superior performance due to the possibility of using all rated power exclusively to voltage support. This paper presents a simple reactive power control algorithm for Static Synchronous Compensators operating under unbalanced voltage sags. The main feature of the proposed algorithm is that it allows a fine adjustment of the amount of reactive power injected by the positive- and negative-sequence components. Thus the control algorithm provides voltage support at the output of the Static Synchronous compensator. Specifically the proposed control conveniently corrects both the positive- and negative-sequence voltage. Selected simulation results are provided to validate the proposal.

M S Rahman - One of the best experts on this subject based on the ideXlab platform.

  • agent based reactive power management of power distribution networks with distributed energy generation
    Energy Conversion and Management, 2016
    Co-Authors: M S Rahman, M A Mahmud, H R Pota, Mj Hossain
    Abstract:

    In this paper, a new agent-based distributed reactive power management scheme is proposed to improve the voltage stability of energy distribution systems with distributed generation units. Three types of agents – distribution system agent, estimator agent, and control agent are developed within the multi-agent framework. The agents simultaneously coordinated their activities through the online information and energy flow. The overall achievement of the proposed scheme depends on the coordination between two tasks – (i) estimation of reactive power using voltage variation formula and (ii) necessary control actions to provide the estimated reactive power to the distribution networks through the distributed Static Synchronous Compensators. A linear quadratic regulator with a proportional integrator is designed for the control agent in order to control the reactive component of the current and the DC voltage of the Compensators. The performance of the proposed scheme is tested on a 10-bus power distribution network under various scenarios. The effectiveness is validated by comparing the proposed approach to the conventional proportional integral control approach. It is found that, the agent-based scheme provides excellent robust performance under various operating conditions of the power distribution network.

  • distributed multi agent scheme for reactive power management with renewable energy
    Energy Conversion and Management, 2014
    Co-Authors: M S Rahman, M A Mahmud, H R Pota, Mj Hossain
    Abstract:

    This paper presents a new distributed multi-agent scheme for reactive power management in smart coordinated distribution networks with renewable energy sources (RESs) to enhance the dynamic voltage stability, which is mainly based on controlling distributed Static Synchronous Compensators (DSTATCOMs). The proposed control scheme is incorporated in a multi-agent framework where the intelligent agents simultaneously coordinate with each other and represent various physical models to provide information and energy flow among different physical processes. The reactive power is estimated from the topology of distribution networks and with this information, necessary control actions are performed through the proposed proportional integral (PI) controller. The performance of the proposed scheme is evaluated on a 8-bus distribution network under various operating conditions. The performance of the proposed scheme is validated through simulation results and these results are compared to that of conventional PI-based DSTATCOM control scheme. From simulation results, it is found that the distributed MAS provides excellence performance for improving voltage profiles by managing reactive power in a smarter way.