Johan Driesen - Academia.edu (original) (raw)

Papers by Johan Driesen

2009 IEEE/PES Power Systems Conference and Exposition, 2009

Power systems worldwide have gone through a transition from vertically integrated into liberalize... more Power systems worldwide have gone through a transition from vertically integrated into liberalized energy markets. At the same time, increased environmental concerns are promoting the use of renewable and efficient generation technologies. Consequently, a growing number of small-scale Distributed Energy Resources (DER) are being installed in distribution systems. Passive operation of DER can result in severe grid operation problems. In contrast, active DER management can bring mutual benefits for the DER owner as well as Distribution System Operators (DSO). In this article a flexible multi-objective optimization scheme is presented in which DER placement and optimal ancillary services are evaluated and compared with conventional grid reinforcements. This allows assessing the potential of optimal active DER management and evaluating different tariff schemes for DER connection at different levels of DER in the grid. The proposed method uses a hybrid Strength Pareto Evolutionary Algorithm (SPEA2) with a distribution Optimal Power Flow (OPF). Results are analyzed using the UKGDS 355-bus system.

2005 International Conference on Future Power Systems, 2005

In this article the effect of motor starting on the voltages and currents in weak grids is analyz... more In this article the effect of motor starting on the voltages and currents in weak grids is analyzed. The objective is to find the size of the largest motor that can be started from the grid in an acceptable way, called the hosting capacity for motor starting. An overview of the different types of weak grids is given. Important are the measures that can be taken to improve the grid operation and increase the hosting capacity

IET Colloquium on Reliability of Electromagnetic Systems, 2007

This paper studies a torque estimation model for induction machines. The model requires different... more This paper studies a torque estimation model for induction machines. The model requires different machine parameters as input. Since the input parameters are deduced from measurements burdened with inaccuracy, it is necessary to take into account uncertainty in the input of the model. On that account the distribution and the interdependence of the input parameters is determined. A sufficient data

IET Conference Publications, 2009

Alternative vehicles, such as plug-in hybrid electric vehicles (PHEVs), become more popular. The ... more Alternative vehicles, such as plug-in hybrid electric vehicles (PHEVs), become more popular. The batteries of these PHEVs are designed to be charged at home, from a standard outlet in the garage, or on a corporate car park. These extra electrical loads have an impact on the distribution grid. The uncoordinated power consumption on a local scale can lead to grid

2006 IEEE PES Power Systems Conference and Exposition, 2006

... Weighted multi-objective optimization proves the presence of topologies with better performan... more ... Weighted multi-objective optimization proves the presence of topologies with better performance. ... and main grid power flows) with some reverses of the medal (DER installation cost and gas distribution grid expansion). ... the topology of pipelines, transmission capacities and ...

2008 18th International Conference on Electrical Machines, 2008

In this paper a torque estimation model for induction machines is studied. The model requires sev... more In this paper a torque estimation model for induction machines is studied. The model requires several machine parameters as input. Since the input parameters are deduced from measurements burdened with inaccuracy, it is necessary to take into account uncertainty in the input of the model. A first order and second order reliability method are performed to evaluate the probability of

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

In this paper, a drive model for a low-power rotary UPS system is described. Traditionally static... more In this paper, a drive model for a low-power rotary UPS system is described. Traditionally static UPS systems are preferred for low-power applications, although rotary UPS systems offer some interesting advantages. A comparison between both types is made to highlight these advantages. Three drive models are presented, with their advantages and disadvantages and a comparison is made to determine the most interesting model, considering both technical and economical aspects. The drive model based on a doubly-fed induction machine (DFIM) is further investigated by simulation as well as using an experimental setup. A case study investigating the inverter power rating as a function of the DFIM's stator power is included. The inverter control schemes are described in detail and the operation of the UPS system is illustrated, both in grid-connected mode and in islanding operation

Power Systems Conference and Exposition, PSCE, IEEE, 2009

Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehi... more Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehicle (HEV), the plug-in hybrid electric vehicle (PHEV) and the fuel-cell electric vehicle (FCEV), are becoming increasingly popular. HEVs are currently commercially available and PHEVs will be the next phase in the evolution of hybrid and electric vehicles. The batteries of the PHEVs are designed to be

IEEE Transactions on Power Systems, 2010

Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The ba... more Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The batteries of these plug-in hybrid electric vehicles are to be charged at home from a standard outlet or on a corporate car park. These extra electrical loads have an impact on the distribution grid which is analyzed in terms of power losses and voltage deviations. Without coordination

The charging of batteries of plug-in hybrid electric vehicles at home at standard outlets has an ... more The charging of batteries of plug-in hybrid electric vehicles at home at standard outlets has an impact on the distribution grid which may require serious investments in grid expansion. The coordination of the charging gives an improvement of the grid exploitation in terms of reduced power losses and voltage deviations with respect to uncoordinated charging. The vehicles must be dispatchable to achieve the most efficient solution. As the exact forecasting of household loads is not possible, stochastic programming is introduced. Two main techniques are analyzed in this paper: quadratic and dynamic programming. Both techniques are compared in results and storage requirements. The charging can be coordinated directly or indirectly by the grid utility or an aggregator who will sell the aggregated demand of PHEVs at the utility. PHEVs can also discharge and so inject energy in the grid to restrict voltage drops. The amount of energy that is injected in the grid depends on the price tariffs, the charging and discharging efficiencies and the battery energy content. The impact of a voltage controller embedded in a PHEV charger is regarded in this paper. A day and night tariff are applied. The charging and discharging of vehicles can respond to real-time pricing or on a price-schedule as well. Voltage control is the first step in the utilization of distributed resources like PHEVs for ancillary services.

2009 IEEE/PES Power Systems Conference and Exposition, 2009

Abstract Alternative vehicles based on internal combustion engines (ICE), such as the hybrid elec... more Abstract Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehicle (HEV), the plug-in hybrid electric vehicle (PHEV) and the fuel-cell electric vehicle (FCEV), are becoming increasingly popular. HEVs are currently commercially ...

2007 IEEE Lausanne Power Tech, 2007

This paper discusses uncertainties in distribution system analysis. Special emphasis lies with di... more This paper discusses uncertainties in distribution system analysis. Special emphasis lies with distributed generation (DG) units. Both backward-forward sweeps and Newton-Raphson based current injection updates are discussed. A first class of stochastic modeling is of probabilistic nature. In analytic probabilistic methods a linearization of the power flow equations is applied. Non-linearities are respected in numerical Monte Carlo analysis when using the appropriate convergence criteria. The second class uses qualitative uncertainty descriptions in boundary and fuzzy power flow methods. Correlation of loads and DG is always a crucial aspect. These aspects are elaborated with regard to robust methodologies for setting benchmarks of DG performance based on stochastic programming and evolutionary algorithms.

IET Renewable Power Generation, 2009

The amount of distributed energy resources (DER) in the grid is continually increasing, and the p... more The amount of distributed energy resources (DER) in the grid is continually increasing, and the potential benefits and drawbacks are becoming clearer. However, there is still a lack of clarity in how these multiple effects interact and which trade-offs should be made in the integration of new DER. There is a clear need for appropriate DER planning tools in the current market environment, in which both DER operators and distribution system operators (DSOs) may have multiple, often conflicting objectives and where uncertainty remains present as to which targets can be reached with a high amount of DER in the grid. A novel multi-objective planning framework is presented for the integration of stochastic and controllable DER in the distribution grid. A case study that illustrates the proposed framework is presented. Active DER management in terms of curtailment as well as dispatch of units is studied using the proposed multi-objective approach. Additionally, the extent to which active DER can be used as an alternative for grid reinforcements is analysed. The results show that the proposed multi-objective approach permits a better evaluation of the potential of active DER to support system operation.

IET Renewable Power Generation, 2007

The number of distributed generation (DG) units being connected at the low-and medium-voltage lev... more The number of distributed generation (DG) units being connected at the low-and medium-voltage level is evermore increasing. Because of the mostly non-dispatchable generation profile of small-scale renewable power sources, grid performance can be ameliorated as well as deteriorated. A traditional mathematical optimisation of techno-economic objectives is elaborated upon. A conservative approach can, however, easily underestimate performance deviations due to the stochastic output of DG. A robust planning methodology is formulated, based on accuracy improving Monte Carlo simulations nested in an evolutionary algorithm. Multiple objectives are pursued to assess proper trade-offs regarding the technical and economical aspects.

IEEE Transactions on Power Systems, 2000

Abstract—This paper discusses the impact of uncertain power injections in the grid on the load ma... more Abstract—This paper discusses the impact of uncertain power injections in the grid on the load margin. Two common analyses of voltage stability are those aiming for the closest saddle node bifur-cation and those assuming a prefixed direction of load and produc-tion increase. In ...

IEEE Transactions on Power Systems, 2000

Abstract Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popula... more Abstract Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The batteries of these plug-in hybrid electric vehicles are to be charged at home from a standard outlet or on a corporate car park. These extra electrical loads have an ...

Electric Power Systems Research, 2011

Plug-in hybrid electric vehicles (PHEVs) can be connected to the power grid. The power flow of th... more Plug-in hybrid electric vehicles (PHEVs) can be connected to the power grid. The power flow of this connection can be bidirectional, so vehicles can charge and discharge. This vehicle-to-grid option can aid to improve grid efficiency and reliability. A simulation covering an entire day is essential to obtain an accurate assessment of the impact of PHEVs. It is important to know when, statistically, vehicles are available for charging or discharging. In this work is shown that uncoordinated charging of PHEVs in distribution grid can lead to local grid problems. Therefore, coordinated charging and discharging is investigated and a voltage constraint is implemented. These vehicles can support the grid in terms of voltage control and congestion management. In that way, the distribution grid can handle more PHEVs without reinforcements. Distributed generation units are more common nowadays in the distribution grid with some of these generation units based on intermittent renewable resources. This paper shows that there could be a good combination with PHEVs as they can provide storage to take care of the excess of produced energy and use it for driving or release it into the grid at a later time. In that way, consumption and generation are more efficiently matched.

In this paper, a drive model for a low-power ro- tary UPS system is described. Nowadays static UP... more In this paper, a drive model for a low-power ro- tary UPS system is described. Nowadays static UPS systems are preferred for low-power applications, although rotary UPS systems offer some interesting advantages. A comparison be- tween both types is made, as to highlight these advantages. Three drive models are presented, with their advantages and disadvantages and a comparison is made

Abstract—The output of a power system analysis mostly requires extensive knowledge and correct ha... more Abstract—The output of a power system analysis mostly requires extensive knowledge and correct handling of input uncertainties. Analytical approaches often depend on simplified models whereas Monte Carlo based sampling methods are often time consuming. This paper presents an ...

2009 IEEE/PES Power Systems Conference and Exposition, 2009

Power systems worldwide have gone through a transition from vertically integrated into liberalize... more Power systems worldwide have gone through a transition from vertically integrated into liberalized energy markets. At the same time, increased environmental concerns are promoting the use of renewable and efficient generation technologies. Consequently, a growing number of small-scale Distributed Energy Resources (DER) are being installed in distribution systems. Passive operation of DER can result in severe grid operation problems. In contrast, active DER management can bring mutual benefits for the DER owner as well as Distribution System Operators (DSO). In this article a flexible multi-objective optimization scheme is presented in which DER placement and optimal ancillary services are evaluated and compared with conventional grid reinforcements. This allows assessing the potential of optimal active DER management and evaluating different tariff schemes for DER connection at different levels of DER in the grid. The proposed method uses a hybrid Strength Pareto Evolutionary Algorithm (SPEA2) with a distribution Optimal Power Flow (OPF). Results are analyzed using the UKGDS 355-bus system.

2005 International Conference on Future Power Systems, 2005

In this article the effect of motor starting on the voltages and currents in weak grids is analyz... more In this article the effect of motor starting on the voltages and currents in weak grids is analyzed. The objective is to find the size of the largest motor that can be started from the grid in an acceptable way, called the hosting capacity for motor starting. An overview of the different types of weak grids is given. Important are the measures that can be taken to improve the grid operation and increase the hosting capacity

IET Colloquium on Reliability of Electromagnetic Systems, 2007

This paper studies a torque estimation model for induction machines. The model requires different... more This paper studies a torque estimation model for induction machines. The model requires different machine parameters as input. Since the input parameters are deduced from measurements burdened with inaccuracy, it is necessary to take into account uncertainty in the input of the model. On that account the distribution and the interdependence of the input parameters is determined. A sufficient data

IET Conference Publications, 2009

Alternative vehicles, such as plug-in hybrid electric vehicles (PHEVs), become more popular. The ... more Alternative vehicles, such as plug-in hybrid electric vehicles (PHEVs), become more popular. The batteries of these PHEVs are designed to be charged at home, from a standard outlet in the garage, or on a corporate car park. These extra electrical loads have an impact on the distribution grid. The uncoordinated power consumption on a local scale can lead to grid

2006 IEEE PES Power Systems Conference and Exposition, 2006

... Weighted multi-objective optimization proves the presence of topologies with better performan... more ... Weighted multi-objective optimization proves the presence of topologies with better performance. ... and main grid power flows) with some reverses of the medal (DER installation cost and gas distribution grid expansion). ... the topology of pipelines, transmission capacities and ...

2008 18th International Conference on Electrical Machines, 2008

In this paper a torque estimation model for induction machines is studied. The model requires sev... more In this paper a torque estimation model for induction machines is studied. The model requires several machine parameters as input. Since the input parameters are deduced from measurements burdened with inaccuracy, it is necessary to take into account uncertainty in the input of the model. A first order and second order reliability method are performed to evaluate the probability of

IECON 2006 - 32nd Annual Conference on IEEE Industrial Electronics, 2006

In this paper, a drive model for a low-power rotary UPS system is described. Traditionally static... more In this paper, a drive model for a low-power rotary UPS system is described. Traditionally static UPS systems are preferred for low-power applications, although rotary UPS systems offer some interesting advantages. A comparison between both types is made to highlight these advantages. Three drive models are presented, with their advantages and disadvantages and a comparison is made to determine the most interesting model, considering both technical and economical aspects. The drive model based on a doubly-fed induction machine (DFIM) is further investigated by simulation as well as using an experimental setup. A case study investigating the inverter power rating as a function of the DFIM's stator power is included. The inverter control schemes are described in detail and the operation of the UPS system is illustrated, both in grid-connected mode and in islanding operation

Power Systems Conference and Exposition, PSCE, IEEE, 2009

Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehi... more Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehicle (HEV), the plug-in hybrid electric vehicle (PHEV) and the fuel-cell electric vehicle (FCEV), are becoming increasingly popular. HEVs are currently commercially available and PHEVs will be the next phase in the evolution of hybrid and electric vehicles. The batteries of the PHEVs are designed to be

IEEE Transactions on Power Systems, 2010

Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The ba... more Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The batteries of these plug-in hybrid electric vehicles are to be charged at home from a standard outlet or on a corporate car park. These extra electrical loads have an impact on the distribution grid which is analyzed in terms of power losses and voltage deviations. Without coordination

The charging of batteries of plug-in hybrid electric vehicles at home at standard outlets has an ... more The charging of batteries of plug-in hybrid electric vehicles at home at standard outlets has an impact on the distribution grid which may require serious investments in grid expansion. The coordination of the charging gives an improvement of the grid exploitation in terms of reduced power losses and voltage deviations with respect to uncoordinated charging. The vehicles must be dispatchable to achieve the most efficient solution. As the exact forecasting of household loads is not possible, stochastic programming is introduced. Two main techniques are analyzed in this paper: quadratic and dynamic programming. Both techniques are compared in results and storage requirements. The charging can be coordinated directly or indirectly by the grid utility or an aggregator who will sell the aggregated demand of PHEVs at the utility. PHEVs can also discharge and so inject energy in the grid to restrict voltage drops. The amount of energy that is injected in the grid depends on the price tariffs, the charging and discharging efficiencies and the battery energy content. The impact of a voltage controller embedded in a PHEV charger is regarded in this paper. A day and night tariff are applied. The charging and discharging of vehicles can respond to real-time pricing or on a price-schedule as well. Voltage control is the first step in the utilization of distributed resources like PHEVs for ancillary services.

2009 IEEE/PES Power Systems Conference and Exposition, 2009

Abstract Alternative vehicles based on internal combustion engines (ICE), such as the hybrid elec... more Abstract Alternative vehicles based on internal combustion engines (ICE), such as the hybrid electric vehicle (HEV), the plug-in hybrid electric vehicle (PHEV) and the fuel-cell electric vehicle (FCEV), are becoming increasingly popular. HEVs are currently commercially ...

2007 IEEE Lausanne Power Tech, 2007

This paper discusses uncertainties in distribution system analysis. Special emphasis lies with di... more This paper discusses uncertainties in distribution system analysis. Special emphasis lies with distributed generation (DG) units. Both backward-forward sweeps and Newton-Raphson based current injection updates are discussed. A first class of stochastic modeling is of probabilistic nature. In analytic probabilistic methods a linearization of the power flow equations is applied. Non-linearities are respected in numerical Monte Carlo analysis when using the appropriate convergence criteria. The second class uses qualitative uncertainty descriptions in boundary and fuzzy power flow methods. Correlation of loads and DG is always a crucial aspect. These aspects are elaborated with regard to robust methodologies for setting benchmarks of DG performance based on stochastic programming and evolutionary algorithms.

IET Renewable Power Generation, 2009

The amount of distributed energy resources (DER) in the grid is continually increasing, and the p... more The amount of distributed energy resources (DER) in the grid is continually increasing, and the potential benefits and drawbacks are becoming clearer. However, there is still a lack of clarity in how these multiple effects interact and which trade-offs should be made in the integration of new DER. There is a clear need for appropriate DER planning tools in the current market environment, in which both DER operators and distribution system operators (DSOs) may have multiple, often conflicting objectives and where uncertainty remains present as to which targets can be reached with a high amount of DER in the grid. A novel multi-objective planning framework is presented for the integration of stochastic and controllable DER in the distribution grid. A case study that illustrates the proposed framework is presented. Active DER management in terms of curtailment as well as dispatch of units is studied using the proposed multi-objective approach. Additionally, the extent to which active DER can be used as an alternative for grid reinforcements is analysed. The results show that the proposed multi-objective approach permits a better evaluation of the potential of active DER to support system operation.

IET Renewable Power Generation, 2007

The number of distributed generation (DG) units being connected at the low-and medium-voltage lev... more The number of distributed generation (DG) units being connected at the low-and medium-voltage level is evermore increasing. Because of the mostly non-dispatchable generation profile of small-scale renewable power sources, grid performance can be ameliorated as well as deteriorated. A traditional mathematical optimisation of techno-economic objectives is elaborated upon. A conservative approach can, however, easily underestimate performance deviations due to the stochastic output of DG. A robust planning methodology is formulated, based on accuracy improving Monte Carlo simulations nested in an evolutionary algorithm. Multiple objectives are pursued to assess proper trade-offs regarding the technical and economical aspects.

IEEE Transactions on Power Systems, 2000

Abstract—This paper discusses the impact of uncertain power injections in the grid on the load ma... more Abstract—This paper discusses the impact of uncertain power injections in the grid on the load margin. Two common analyses of voltage stability are those aiming for the closest saddle node bifur-cation and those assuming a prefixed direction of load and produc-tion increase. In ...

IEEE Transactions on Power Systems, 2000

Abstract Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popula... more Abstract Alternative vehicles, such as plug-in hybrid electric vehicles, are becoming more popular. The batteries of these plug-in hybrid electric vehicles are to be charged at home from a standard outlet or on a corporate car park. These extra electrical loads have an ...

Electric Power Systems Research, 2011

Plug-in hybrid electric vehicles (PHEVs) can be connected to the power grid. The power flow of th... more Plug-in hybrid electric vehicles (PHEVs) can be connected to the power grid. The power flow of this connection can be bidirectional, so vehicles can charge and discharge. This vehicle-to-grid option can aid to improve grid efficiency and reliability. A simulation covering an entire day is essential to obtain an accurate assessment of the impact of PHEVs. It is important to know when, statistically, vehicles are available for charging or discharging. In this work is shown that uncoordinated charging of PHEVs in distribution grid can lead to local grid problems. Therefore, coordinated charging and discharging is investigated and a voltage constraint is implemented. These vehicles can support the grid in terms of voltage control and congestion management. In that way, the distribution grid can handle more PHEVs without reinforcements. Distributed generation units are more common nowadays in the distribution grid with some of these generation units based on intermittent renewable resources. This paper shows that there could be a good combination with PHEVs as they can provide storage to take care of the excess of produced energy and use it for driving or release it into the grid at a later time. In that way, consumption and generation are more efficiently matched.

In this paper, a drive model for a low-power ro- tary UPS system is described. Nowadays static UP... more In this paper, a drive model for a low-power ro- tary UPS system is described. Nowadays static UPS systems are preferred for low-power applications, although rotary UPS systems offer some interesting advantages. A comparison be- tween both types is made, as to highlight these advantages. Three drive models are presented, with their advantages and disadvantages and a comparison is made

Abstract—The output of a power system analysis mostly requires extensive knowledge and correct ha... more Abstract—The output of a power system analysis mostly requires extensive knowledge and correct handling of input uncertainties. Analytical approaches often depend on simplified models whereas Monte Carlo based sampling methods are often time consuming. This paper presents an ...