Hossein Haghighat - Academia.edu (original) (raw)

Papers by Hossein Haghighat

Research paper thumbnail of Optimal Market Participation of Distributed Load Resources Under Distribution Network Operational Limits and Renewable Generation Uncertainties

IEEE Transactions on Smart Grid, 2018

Distributed load resources are encouraged nowadays to actively participate in the energy market. ... more Distributed load resources are encouraged nowadays to actively participate in the energy market. As a part of the distribution system, they affect the power flow pattern of the network and interact with intermittent renewable generation in the distribution system. In this regard, one fundamental challenge, not yet addressed, is to derive an optimal market participation model, under the demand bidding paradigm, that systemically accounts for the operational limits of a physical distribution grid considering uncertainty associated with both the electricity market and distribution network system. Accordingly, this paper addresses the optimal demand biding under uncertain market and distribution system data and network operational limits. Assuming a price-taker distribution utility with renewable energy, inflexible and deferrable loads and a two-settlement market model, we develop a two-stage robust stochastic bidding formulation solved using a decomposition algorithm. We derive optimal bid curves that minimize energy procurement cost and fully comply with the operational standards of the distribution network. Moreover, novel indexes are proposed to help the utility evaluate the operational performance of its network with regard to deferrable loads and renewable resources. Finally, we illustrate the advantage of the proposed model from a set of numerical experiments on an example system and the 33-bus system.

Research paper thumbnail of Distribution System Reconfiguration Under Uncertain Load and Renewable Generation

IEEE Transactions on Power Systems, 2016

Increasing penetration of variable loads and renewable generation will cause the conventional ope... more Increasing penetration of variable loads and renewable generation will cause the conventional operation strategy of the distribution system to become less certain and effective. This paper presents a method of determining the minimum loss network configuration of a distribution system with uncertain load and renewable generation. A robust optimization model is proposed wherein the optimal decisions on network configurations and losses are derived in two subsequent steps. The first step enforces the radiality constraint before knowing the actual system loads and output level of renewable generation. Power flows are computed next to achieve minimum network losses considering the worst operating conditions over the uncertainty sets. A mixed-integer two-stage robust optimization formulation and a decomposition algorithm in a master-slave structure are proposed to solve the problem. Results of an illustrative example and two test systems are presented to demonstrate the proposed method.

Research paper thumbnail of A model for reactive power pricing and dispatch of distributed generation

IEEE PES General Meeting, 2010

This paper proposes a new pricing mechanism and dispatch model for reactive power service from di... more This paper proposes a new pricing mechanism and dispatch model for reactive power service from distributed generation (DG) resources, including wind turbines and solar photovoltaic plants, connected to a low voltage distribution system. Novel cost functions of reactive power service are proposed for DG resources as well as alternative VAR suppliers such as STATCOM and capacitor banks, taking into account their operational and fixed costs of reactive power provision. The real-time reactive power price is calculated based on the real power losses incurred for reactive power generation, while additional fixed payments are made to ensure capital cost recovery. An optimal power flow (OPF) model is developed which seeks to minimize the total payments of the Distribution Company (DisCo) for active and reactive power services while maintaining the system security. Two types of DG technologies are considered in this work: wind turbines equipped with doubly-fed induction generators (DFIG) and photovoltaic (PV) plants. The reactive power characteristics and different voltage strategies of these DG sources are also included in the OPF model. A test distribution system and a numerical example are used system to illustrate the application of the proposed method.

Research paper thumbnail of UHV for Iranian power grid, will it be a reality?

Canadian Conference on Electrical and Computer Engineering, 2005.

The transmission system of Iranian power grid comprises 400 and 230 kV elements. Rapid annual dem... more The transmission system of Iranian power grid comprises 400 and 230 kV elements. Rapid annual demand increase of 7-9% would increase power consumption of current 29000 MW to 67000 MW within the next 15 years. Most of the consumption is located towards central and north regions, while new generation requirements may be towards south regions with new high fossil fuel

Research paper thumbnail of A new reactive power planning procedure for Iranian Power Grid

Electric Power Systems Research, 2004

Reactive power planning has received considerably attention during the last few years. Allocation... more Reactive power planning has received considerably attention during the last few years. Allocation of reactive power resources of both static (ex. switchable capacitors and/or reactors) and dynamic (ex. static VAr compensators, or SVCs) types can have major impacts on voltage security (i.e. voltage profile and stability) and active power losses. They, however, impose costs so that the planning procedure is, indeed, an optimization problem in which the resources should be so allocated and sized that optimum performance, in terms of voltage profile and stability and minimum active power losses are achieved while, at the same time, minimum reactive power resource costs are imposed. This problem is addressed in this paper for the multi-zone Iranian Power Grid. Genetic Algorithm (GA) is employed to solve the resulting multi-objective optimization problem. The system under study is a large-scale test case so that new approaches are proposed to tackle the problem. Implementation of the results are underway.

Research paper thumbnail of An initial-point strategy for optimizing distribution system reconfiguration

Electric Power Systems Research, 2019

This study presents a simple and fast strategy for selecting the candidate solutions of the distr... more This study presents a simple and fast strategy for selecting the candidate solutions of the distribution system reconfiguration problem without solving optimization based or load flow based programs. It consists of constructing a node-node adjacency matrix of the original network topology in which specific diagonal entries corresponding to the off-diagonal ones represent the favourable candidate solutions. This strategy needs only primitive network information and is applicable to any optimization method and network dimension without affecting the computational tractability of the problem. Through numerical experiments on various test systems, the efficacy of the proposed scheme is illustrated.

Research paper thumbnail of Generic Resource Allocation in Distribution Grid

IEEE Transactions on Power Systems, 2019

This work presents a generic method for allocating active and reactive power resources in the dis... more This work presents a generic method for allocating active and reactive power resources in the distribution network. It is based on the conventional AC load flow model and can provide accurate results without solving sophisticated optimization programs. Numerical results of standard test systems are presented which indicate the proposed method, compared to the optimization based approaches, can quickly attain accurate and easy-to-compute decisions.

Research paper thumbnail of A Bilevel Approach to Operational Decision Making of a Distribution Company in Competitive Environments

IEEE Transactions on Power Systems, 2012

ABSTRACT This paper presents a model for operational decision making of a distribution company (d... more ABSTRACT This paper presents a model for operational decision making of a distribution company (disco) with distributed generation (DG) and interruptible loads (IL) in a competitive market. The disco objective, modeled through the upper-level problem, is to minimize the cost of market purchases and DG unit dispatch while taking into account the responses of the other discos. This upper-level problem is constrained by a lower-level market clearing problem whose objective corresponds to maximization of social welfare. Such a setting results in a multi-disco equilibrium problem formulated as an equilibrium problem with equilibrium constraints (EPEC) by combining the optimality conditions of all upper-level problems. Using a nonlinear approach, the EPEC problem is reformulated as a single nonlinear optimization model which is simultaneously solved for all discos. The proposed approach is applied to an ac model of a power system to account for voltage and reactive power constraints of the transmission and distribution networks. Numerical examples based on two test systems are presented to illustrate the application of the proposed method.

Research paper thumbnail of Smart Online Protection System for Power Transmission Towers: An IoT-Aided Design and Implementation

IEEE Internet of Things Journal

Research paper thumbnail of Optimal Placement and Sizing of Electric Vehicles Charging Stations Based on Voltage Stability Index and Loss Reduction in Distribution Grid

Iranian Journal of Energy, Sep 10, 2019

Research paper thumbnail of Example system and 118-bus system (power and gas systems)

Data used in the numerical results of the example system and 118-bus system (power and gas systems)

Research paper thumbnail of Co-Optimization of Battery Storage Investment and Grid Expansion in Integrated Energy Systems

IEEE Systems Journal, 2021

Research paper thumbnail of Stochastic network investment in integrated gas-electric systems

Electric Power Systems Research, 2021

Abstract Power and gas systems are large interdependent infrastructures because of gas-fired powe... more Abstract Power and gas systems are large interdependent infrastructures because of gas-fired power production facilities. This study presents a transmission expansion planning model considering the interaction between power and gas markets in a bi-level structure. The transmission investment decisions are made in the upper level power market problem considering the construction and operating costs. The lower level problem clears the gas market and determines demand and supply quantities of gas-fired units and of gas wells using a mixed integer linear program. The uncertainty of gas and power demands in both markets are considered using a scenario-based approach. A stochastic bilevel mixed integer optimization program is thus developed which is computed in an exact fashion by applying a customized reformulation-decomposition method. An example system and a test system are provided to illustrate the application of the proposed scheme.

Research paper thumbnail of Integrating Energy Management of Autonomous Smart Grids in Electricity Market Operation

IEEE Transactions on Smart Grid, 2020

This study presents a market operation model integrated with energy management programs of indepe... more This study presents a market operation model integrated with energy management programs of independent smart grids using bilevel optimization. In this framework, autonomous smart grid entities, in the lower levels, operate their own networks and send decisions to the upper level market operator that clears the day ahead market based on unit commitment and second order conic AC power flow models. A single-leader multi-follower game is thus developed, in which every smart grid derives optimal schedules of its own renewable energy resources, storage devices, and responsive demands that are interconnected through a distribution grid using mixed integer linear programming. Given the mixed integer nature of the upper and lower level decisions, we develop and customize an exact reformulation-decomposition method to compute this bilevel optimization program. Through numerical experiments performed on three test systems, we demonstrate that the proposed modeling paradigm can accurately represent the physics of the transmission and distribution grids and achieves reasonable results with significant computational efficacy.

Research paper thumbnail of Bilevel Mixed Integer Transmission Expansion Planning

IEEE Transactions on Power Systems, 2018

This study presents a bilevel transmission expansion planning model with mixed integer programmin... more This study presents a bilevel transmission expansion planning model with mixed integer programming (MIP) market clearing problem considering production cost nonconvexities. We use a customized reformulation-and-decomposition scheme to solve this challenging bilevel MIP. Comparative results from this model with respect to a conventional bilevel model with linear programming market clearing are presented to show the impact of nonconvexities on the transmission expansion decisions.

Research paper thumbnail of Bilevel Conic Transmission Expansion Planning

IEEE Transactions on Power Systems, 2018

Research paper thumbnail of Stochastic and Chance-Constrained Conic Distribution System Expansion Planning Using Bilinear Benders Decomposition

IEEE Transactions on Power Systems, 2017

Research paper thumbnail of Loading margin calculation with line switching: A decomposition method

International Journal of Electrical Power & Energy Systems, 2015

ABSTRACT This paper presents a model for loading margin calculation integrated with transmission ... more ABSTRACT This paper presents a model for loading margin calculation integrated with transmission line switching. A mixed-integer nonlinear optimization model is developed which maximizes the loading margin of the system subject to various operational system constraints. An iterative algorithm, based on the Benders decomposition method, is used to solve the problem. The proposed method is tested on medium and large scale test systems and optimization results are compared with that of a non-decomposed method to show the efficacy of the proposed approach.

Research paper thumbnail of Energy loss reduction by optimal distributed generation allocation in distribution systems

International Transactions on Electrical Energy Systems, 2014

This paper presents a mixed-integer nonlinear optimization model for distributed generation (DG) ... more This paper presents a mixed-integer nonlinear optimization model for distributed generation (DG) placement in the distribution system. A multiperiod ac optimal power-flow model is developed for minimizing annual energy losses and determining the optimal site and size of DG units. Various system constraints and time-varying demands are incorporated in the model. A novel iterative method for solving the multiperiod DG placement problem based on the Benders decomposition technique is proposed, which reduces the computational burden and facilitates its practical application. Two case studies are presented to illustrate the efficacy of the proposed method.

Research paper thumbnail of Strategic offering under uncertainty in power markets

International Journal of Electrical Power & Energy Systems, 2014

A power producer implementing nominal strategy can be penalized if not planning for randomness or... more A power producer implementing nominal strategy can be penalized if not planning for randomness or will lose profit if protects its decisions against the most severe outcome. The robust optimization approach achieves a trade-off between these two extremes. This paper presents a robust method for deriving offers of a strategic generator under uncertainty. The problem is formulated as a bilevel mathematical program wherein the strategic generator, in the upper level, maximizes its profit subject to a transmission-constrained economic dispatch model in the lower-level. The randomness of input parameters in the lower-level problem involving rival offers and market demand, are modeled using uncertainty sets. The bilevel optimization model is then transformed into a mixed-integer linear optimization problem by deriving the robust counterpart of the lower-level problem and making use of a linearization-reformulation technique. Numerical results of several case studies are presented to illustrate the application of the proposed method.

Research paper thumbnail of Optimal Market Participation of Distributed Load Resources Under Distribution Network Operational Limits and Renewable Generation Uncertainties

IEEE Transactions on Smart Grid, 2018

Distributed load resources are encouraged nowadays to actively participate in the energy market. ... more Distributed load resources are encouraged nowadays to actively participate in the energy market. As a part of the distribution system, they affect the power flow pattern of the network and interact with intermittent renewable generation in the distribution system. In this regard, one fundamental challenge, not yet addressed, is to derive an optimal market participation model, under the demand bidding paradigm, that systemically accounts for the operational limits of a physical distribution grid considering uncertainty associated with both the electricity market and distribution network system. Accordingly, this paper addresses the optimal demand biding under uncertain market and distribution system data and network operational limits. Assuming a price-taker distribution utility with renewable energy, inflexible and deferrable loads and a two-settlement market model, we develop a two-stage robust stochastic bidding formulation solved using a decomposition algorithm. We derive optimal bid curves that minimize energy procurement cost and fully comply with the operational standards of the distribution network. Moreover, novel indexes are proposed to help the utility evaluate the operational performance of its network with regard to deferrable loads and renewable resources. Finally, we illustrate the advantage of the proposed model from a set of numerical experiments on an example system and the 33-bus system.

Research paper thumbnail of Distribution System Reconfiguration Under Uncertain Load and Renewable Generation

IEEE Transactions on Power Systems, 2016

Increasing penetration of variable loads and renewable generation will cause the conventional ope... more Increasing penetration of variable loads and renewable generation will cause the conventional operation strategy of the distribution system to become less certain and effective. This paper presents a method of determining the minimum loss network configuration of a distribution system with uncertain load and renewable generation. A robust optimization model is proposed wherein the optimal decisions on network configurations and losses are derived in two subsequent steps. The first step enforces the radiality constraint before knowing the actual system loads and output level of renewable generation. Power flows are computed next to achieve minimum network losses considering the worst operating conditions over the uncertainty sets. A mixed-integer two-stage robust optimization formulation and a decomposition algorithm in a master-slave structure are proposed to solve the problem. Results of an illustrative example and two test systems are presented to demonstrate the proposed method.

Research paper thumbnail of A model for reactive power pricing and dispatch of distributed generation

IEEE PES General Meeting, 2010

This paper proposes a new pricing mechanism and dispatch model for reactive power service from di... more This paper proposes a new pricing mechanism and dispatch model for reactive power service from distributed generation (DG) resources, including wind turbines and solar photovoltaic plants, connected to a low voltage distribution system. Novel cost functions of reactive power service are proposed for DG resources as well as alternative VAR suppliers such as STATCOM and capacitor banks, taking into account their operational and fixed costs of reactive power provision. The real-time reactive power price is calculated based on the real power losses incurred for reactive power generation, while additional fixed payments are made to ensure capital cost recovery. An optimal power flow (OPF) model is developed which seeks to minimize the total payments of the Distribution Company (DisCo) for active and reactive power services while maintaining the system security. Two types of DG technologies are considered in this work: wind turbines equipped with doubly-fed induction generators (DFIG) and photovoltaic (PV) plants. The reactive power characteristics and different voltage strategies of these DG sources are also included in the OPF model. A test distribution system and a numerical example are used system to illustrate the application of the proposed method.

Research paper thumbnail of UHV for Iranian power grid, will it be a reality?

Canadian Conference on Electrical and Computer Engineering, 2005.

The transmission system of Iranian power grid comprises 400 and 230 kV elements. Rapid annual dem... more The transmission system of Iranian power grid comprises 400 and 230 kV elements. Rapid annual demand increase of 7-9% would increase power consumption of current 29000 MW to 67000 MW within the next 15 years. Most of the consumption is located towards central and north regions, while new generation requirements may be towards south regions with new high fossil fuel

Research paper thumbnail of A new reactive power planning procedure for Iranian Power Grid

Electric Power Systems Research, 2004

Reactive power planning has received considerably attention during the last few years. Allocation... more Reactive power planning has received considerably attention during the last few years. Allocation of reactive power resources of both static (ex. switchable capacitors and/or reactors) and dynamic (ex. static VAr compensators, or SVCs) types can have major impacts on voltage security (i.e. voltage profile and stability) and active power losses. They, however, impose costs so that the planning procedure is, indeed, an optimization problem in which the resources should be so allocated and sized that optimum performance, in terms of voltage profile and stability and minimum active power losses are achieved while, at the same time, minimum reactive power resource costs are imposed. This problem is addressed in this paper for the multi-zone Iranian Power Grid. Genetic Algorithm (GA) is employed to solve the resulting multi-objective optimization problem. The system under study is a large-scale test case so that new approaches are proposed to tackle the problem. Implementation of the results are underway.

Research paper thumbnail of An initial-point strategy for optimizing distribution system reconfiguration

Electric Power Systems Research, 2019

This study presents a simple and fast strategy for selecting the candidate solutions of the distr... more This study presents a simple and fast strategy for selecting the candidate solutions of the distribution system reconfiguration problem without solving optimization based or load flow based programs. It consists of constructing a node-node adjacency matrix of the original network topology in which specific diagonal entries corresponding to the off-diagonal ones represent the favourable candidate solutions. This strategy needs only primitive network information and is applicable to any optimization method and network dimension without affecting the computational tractability of the problem. Through numerical experiments on various test systems, the efficacy of the proposed scheme is illustrated.

Research paper thumbnail of Generic Resource Allocation in Distribution Grid

IEEE Transactions on Power Systems, 2019

This work presents a generic method for allocating active and reactive power resources in the dis... more This work presents a generic method for allocating active and reactive power resources in the distribution network. It is based on the conventional AC load flow model and can provide accurate results without solving sophisticated optimization programs. Numerical results of standard test systems are presented which indicate the proposed method, compared to the optimization based approaches, can quickly attain accurate and easy-to-compute decisions.

Research paper thumbnail of A Bilevel Approach to Operational Decision Making of a Distribution Company in Competitive Environments

IEEE Transactions on Power Systems, 2012

ABSTRACT This paper presents a model for operational decision making of a distribution company (d... more ABSTRACT This paper presents a model for operational decision making of a distribution company (disco) with distributed generation (DG) and interruptible loads (IL) in a competitive market. The disco objective, modeled through the upper-level problem, is to minimize the cost of market purchases and DG unit dispatch while taking into account the responses of the other discos. This upper-level problem is constrained by a lower-level market clearing problem whose objective corresponds to maximization of social welfare. Such a setting results in a multi-disco equilibrium problem formulated as an equilibrium problem with equilibrium constraints (EPEC) by combining the optimality conditions of all upper-level problems. Using a nonlinear approach, the EPEC problem is reformulated as a single nonlinear optimization model which is simultaneously solved for all discos. The proposed approach is applied to an ac model of a power system to account for voltage and reactive power constraints of the transmission and distribution networks. Numerical examples based on two test systems are presented to illustrate the application of the proposed method.

Research paper thumbnail of Smart Online Protection System for Power Transmission Towers: An IoT-Aided Design and Implementation

IEEE Internet of Things Journal

Research paper thumbnail of Optimal Placement and Sizing of Electric Vehicles Charging Stations Based on Voltage Stability Index and Loss Reduction in Distribution Grid

Iranian Journal of Energy, Sep 10, 2019

Research paper thumbnail of Example system and 118-bus system (power and gas systems)

Data used in the numerical results of the example system and 118-bus system (power and gas systems)

Research paper thumbnail of Co-Optimization of Battery Storage Investment and Grid Expansion in Integrated Energy Systems

IEEE Systems Journal, 2021

Research paper thumbnail of Stochastic network investment in integrated gas-electric systems

Electric Power Systems Research, 2021

Abstract Power and gas systems are large interdependent infrastructures because of gas-fired powe... more Abstract Power and gas systems are large interdependent infrastructures because of gas-fired power production facilities. This study presents a transmission expansion planning model considering the interaction between power and gas markets in a bi-level structure. The transmission investment decisions are made in the upper level power market problem considering the construction and operating costs. The lower level problem clears the gas market and determines demand and supply quantities of gas-fired units and of gas wells using a mixed integer linear program. The uncertainty of gas and power demands in both markets are considered using a scenario-based approach. A stochastic bilevel mixed integer optimization program is thus developed which is computed in an exact fashion by applying a customized reformulation-decomposition method. An example system and a test system are provided to illustrate the application of the proposed scheme.

Research paper thumbnail of Integrating Energy Management of Autonomous Smart Grids in Electricity Market Operation

IEEE Transactions on Smart Grid, 2020

This study presents a market operation model integrated with energy management programs of indepe... more This study presents a market operation model integrated with energy management programs of independent smart grids using bilevel optimization. In this framework, autonomous smart grid entities, in the lower levels, operate their own networks and send decisions to the upper level market operator that clears the day ahead market based on unit commitment and second order conic AC power flow models. A single-leader multi-follower game is thus developed, in which every smart grid derives optimal schedules of its own renewable energy resources, storage devices, and responsive demands that are interconnected through a distribution grid using mixed integer linear programming. Given the mixed integer nature of the upper and lower level decisions, we develop and customize an exact reformulation-decomposition method to compute this bilevel optimization program. Through numerical experiments performed on three test systems, we demonstrate that the proposed modeling paradigm can accurately represent the physics of the transmission and distribution grids and achieves reasonable results with significant computational efficacy.

Research paper thumbnail of Bilevel Mixed Integer Transmission Expansion Planning

IEEE Transactions on Power Systems, 2018

This study presents a bilevel transmission expansion planning model with mixed integer programmin... more This study presents a bilevel transmission expansion planning model with mixed integer programming (MIP) market clearing problem considering production cost nonconvexities. We use a customized reformulation-and-decomposition scheme to solve this challenging bilevel MIP. Comparative results from this model with respect to a conventional bilevel model with linear programming market clearing are presented to show the impact of nonconvexities on the transmission expansion decisions.

Research paper thumbnail of Bilevel Conic Transmission Expansion Planning

IEEE Transactions on Power Systems, 2018

Research paper thumbnail of Stochastic and Chance-Constrained Conic Distribution System Expansion Planning Using Bilinear Benders Decomposition

IEEE Transactions on Power Systems, 2017

Research paper thumbnail of Loading margin calculation with line switching: A decomposition method

International Journal of Electrical Power & Energy Systems, 2015

ABSTRACT This paper presents a model for loading margin calculation integrated with transmission ... more ABSTRACT This paper presents a model for loading margin calculation integrated with transmission line switching. A mixed-integer nonlinear optimization model is developed which maximizes the loading margin of the system subject to various operational system constraints. An iterative algorithm, based on the Benders decomposition method, is used to solve the problem. The proposed method is tested on medium and large scale test systems and optimization results are compared with that of a non-decomposed method to show the efficacy of the proposed approach.

Research paper thumbnail of Energy loss reduction by optimal distributed generation allocation in distribution systems

International Transactions on Electrical Energy Systems, 2014

This paper presents a mixed-integer nonlinear optimization model for distributed generation (DG) ... more This paper presents a mixed-integer nonlinear optimization model for distributed generation (DG) placement in the distribution system. A multiperiod ac optimal power-flow model is developed for minimizing annual energy losses and determining the optimal site and size of DG units. Various system constraints and time-varying demands are incorporated in the model. A novel iterative method for solving the multiperiod DG placement problem based on the Benders decomposition technique is proposed, which reduces the computational burden and facilitates its practical application. Two case studies are presented to illustrate the efficacy of the proposed method.

Research paper thumbnail of Strategic offering under uncertainty in power markets

International Journal of Electrical Power & Energy Systems, 2014

A power producer implementing nominal strategy can be penalized if not planning for randomness or... more A power producer implementing nominal strategy can be penalized if not planning for randomness or will lose profit if protects its decisions against the most severe outcome. The robust optimization approach achieves a trade-off between these two extremes. This paper presents a robust method for deriving offers of a strategic generator under uncertainty. The problem is formulated as a bilevel mathematical program wherein the strategic generator, in the upper level, maximizes its profit subject to a transmission-constrained economic dispatch model in the lower-level. The randomness of input parameters in the lower-level problem involving rival offers and market demand, are modeled using uncertainty sets. The bilevel optimization model is then transformed into a mixed-integer linear optimization problem by deriving the robust counterpart of the lower-level problem and making use of a linearization-reformulation technique. Numerical results of several case studies are presented to illustrate the application of the proposed method.