Showing papers on "Electric power system published in 2008"

Microgrids management

Abstract: The environmental and economical benefits of the microgrid and consequently its acceptability and degree of proliferation in the utility power industry, are primarily determined by the envisioned controller capabilities and the operational features. Depending on the type and depth of penetration of distributed energy resource (DER) units, load characteristics and power quality constraints, and market participation strategies, the required control and operational strategies of a microgrid can be significantly, and even conceptually, different than those of the conventional power systems.

System and method for inductive charging of portable devices

Abstract: A system and method for variable power transfer in an inductive charging or power system. In accordance with an embodiment the system comprises a pad or similar base unit that contains a primary, which creates an alternating magnetic field. A receiver comprises a means for receiving the energy from the alternating magnetic field from the pad and transferring it to a mobile device, battery, or other device. In accordance with various embodiments, additional features can be incorporated into the system to provide greater power transfer efficiency, and to allow the system to be easily modified for applications that have different power requirements. These include variations in the material used to manufacture the primary and/or the receiver coils; modified circuit designs to be used on the primary and/or receiver side; and additional circuits and components that perform specialized tasks, such as mobile device or battery identification, and automatic voltage or power-setting for different devices or batteries.

Power system dynamics : stability and control

Abstract: About The Authors. Preface. Acknowledgements. List of Symbols. PART I: INTRODUCTION TO POWER SYSTEMS. 1 Introduction . 1.1 Stability and Control of a Dynamic System. 1.2 Classification of Power System Dynamics. 1.3 Two Pairs of Important Quantities: Reactive Power/Voltage and Real Power/Frequency. 1.4 Stability of Power System. 1.5 Security of Power System. 1.6 Brief Historical Overview. 2. Power System Components. 2.1 Structure of the Electrical Power System. 2.2 Generating Units. 2.3 Substations. 2.4 Transmission and Distribution Network. 2.5 Protection. 2.6 Wide Area Measurement Systems. 3. The Power System in the Steady-State. 3.1. Transmission Lines. 3.2. Transformers. 3.3. Synchronous Generators. 3.4. Power System Loads. 3.5. Network Equations. 3.6. Power Flows in Transmission Networks. PART II: INTRODUCTION TO POWER SYSTEM DYNAMICS. 4. Electromagnetic Phenomena. 4.1. Fundamentals. 4.2. Three-Phase Short-Circuit on a Synchronous Generator. 4.3. Phase-to-Phase Short-Circuit. 4.4. Synchronization. 4.5. Short Circuit in a Network and its Clearing. 5. Electromechanical Dynamics - Small Disturbances. 5.1. Swing Equation. 5.2. Damping Power. 5.3. Equilibrium Points. 5.4. Steady-State Stability of Unregulated System. 5.5. Steady-State Stability of the Regulated System. 6. Electromechanical Dynamics - Large Disturbances. 6.1. Transient Stability. 6.2. Swings in Multi-Machine Systems. 6.3. Direct Method for Stability Assessment. 6.4. Synchronization. 6.5. Asynchronous Operation and Resynchronization. 6.6 Out-Of-Step Protection Systems. 6.7. Torsional Oscillations in the Drive Shaft. 7. Wind Power. 7.1 Wind Turbines. 7.2 Induction Machine Equivalent Circuit. 7.3 Induction Generator Coupled to the Grid. 7.4 Induction Generators with Slightly Increased Speed Range Via External Rotor Resistance. 7.5 Induction Generators with Significantly Increased Speed Range: DFIGs. 7.6 Fully Rated Converter Systems: Wide Speed Control. 7.7 Peak Power Tracking Of Variable Speed Wind Turbines. 7.8 Connections of Wind Farms. 7.9 Fault Behaviour of Induction Generators. 7.10 Influence of Wind Generators on Power System Stability. 8. Voltage Stability. 8.1. Network Feasibility. 8.2. Stability Criteria. 8.3. Critical Load Demand and Voltage Collapse. 8.4. Static Analysis. 8.5. Dynamic Analysis. 8.6. Prevention of Voltage Collapse. 8.7. Self-Excitation of a Generator Operating on a Capacitive Load. 9. Frequency Stability and Control. 9.1. Automatic Generation Control. 9.2. Stage I - Rotor Swings in the Generators. 9.3. Stage II - Frequency Drop. 9.4. Stage III - Primary Control. 9.5. STAGE IV - Secondary Control. 9.6. FACTS Devices in Tie-Lines. 10. Stability Enhancement. 10.1. Power System Stabilizers. 10.2. Fast Valving. 10.3. Braking Resistors. 10.4. Generator Tripping. 10.5. Shunt FACTS Devices. 10.6. Series Compensators. 10.7. Unified Power Flow Controller . PART III: ADVANCED TOPICS IN POWER SYSTEM DYNAMICS. 11. Advanced Power System Modelling. 11.1 Synchronous Generator. 11.2. Excitation Systems. 11.3. Turbines and Turbine Governors. 11.4. FACTS Devices. 12. Steady-State Stability of Multi-Machine System. 12.1. Mathematical Background. 12.2. Steady-State Stability of Unregulated System. 12.3. Steady-State Stability of The Regulated System. 13. Power System Dynamic Simulation. 13.1. Numerical Integration Methods. 13.2. The Partitioned-Solution. 13.3. The Simultaneous Solution Methods. 13.4. Comparison Between the Methods. 14. Power System Model Reduction - Equivalents. 14.1. Types of Equivalents. 14.2. Network Transformation. 14.3. Aggregation of Generating Units. 14.4. Equivalent Model of External Subsystem. 14.5. Coherency Recognition. 14.6. Properties of Coherency-Based Equivalents. Appendix. References. Index.

An Economic Dispatch Model Incorporating Wind Power

Abstract: In solving the electrical power systems economic dispatch (ED) problem, the goal is to find the optimal allocation of output power among the various generators available to serve the system load. With the continuing search for alternatives to conventional energy sources, it is necessary to include wind energy conversion system (WECS) generators in the ED problem. This paper develops a model to include the WECS in the ED problem, and in addition to the classic economic dispatch factors, factors to account for both overestimation and underestimation of available wind power are included. With the stochastic wind speed characterization based on the Weibull probability density function, the optimization problem is numerically solved for a scenario involving two conventional and two wind-powered generators. Optimal solutions are presented for various values of the input parameters, and these solutions demonstrate that the allocation of system generation capacity may be influenced by multipliers related to the risk of overestimation and to the cost of underestimation of available wind power.

Security-Constrained Unit Commitment With Volatile Wind Power Generation

Abstract: This paper presents a security-constrained unit commitment (SCUC) algorithm which takes into account the intermittency and volatility of wind power generation. The UC problem is solved in the master problem with the forecasted intermittent wind power generation. Next, possible scenarios are simulated for representing the wind power volatility. The initial dispatch is checked in the subproblem and generation redispatch is considered for satisfying the hourly volatility of wind power in simulated scenarios. If the redispatch fails to mitigate violations, Benders cuts are created and added to the master problem to revise the commitment solution. The iterative process between the commitment problem and the feasibility check subproblem will continue until simulated wind power scenarios can be accommodated by redispatch. Numerical simulations indicate the effectiveness of the proposed SCUC algorithm for managing the security of power system operation by taking into account the intermittency and volatility of wind power generation.

Stochastic Security for Operations Planning With Significant Wind Power Generation

Abstract: In their attempt to cut down on greenhouse gas emissions from electricity generation, several countries are committed to install wind power generation up to and beyond the 10%-20% penetration mark. However, the large-scale integration of wind power represents a challenge for power system operations planning because wind power 1) cannot be dispatched in the classical sense; and 2) its output varies as weather conditions change. This warrants the investigation of alternative short-term power system operations planning methods capable of better coping with the nature of wind generation while maintaining or even improving the current reliability and economic performance of power systems. To this end, this paper formulates a short-term forward electricity market-clearing problem with stochastic security capable of accounting for nondispatchable and variable wind power generation sources. The principal benefit of this stochastic operation planning approach is that, when compared to a deterministic worst-case scenario planning philosophy, it allows greater wind power penetration without sacrificing security.

Power supply system of vehicle

Abstract: PROBLEM TO BE SOLVED: To provide a power supply system of a vehicle, which can reduce a decline in power performance of a vehicle when it uses a plurality of power supplies in a switching manner or can prevent an excessive current flow when switching the power supplies. SOLUTION: A power supply system of a vehicle is equipped with inverters 14 and 22 which are supplied with electric power from batteries BA, BB1 and BB2; a connecting section 39B for connecting either one of the batteries BB1 and BB2 selectively to the inverters 14 and 22 so as to supply electric power to them; an air conditioner 40 which is supplied with electric power from the battery BA. When the battery (BB1 or BB2) to be selected is changed, a controller 30 stops the operation of the air conditioner 40 temporarily until the change in the connecting section 39B is completed. COPYRIGHT: (C)2010,JPO&INPIT

Stochastic security for operations planning with significant wind power generation

Abstract: In their attempt to cut down on greenhouse gas emissions from electricity generation, several countries are committed to install wind power generation up to and beyond the 10-20% penetration mark. However, the large-scale integration of wind power represents a challenge for power system operations planning because wind power (i) cannot be dispatched in the classical sense; and, (ii) its output varies as weather conditions change. This warrants the investigation of alternative short-term power system operations planning methods capable of better coping with the nature of wind generation while maintaining or even improving the current reliability and economic performance of power systems. To this end, this paper formulates a short-term forward electricity market-clearing problem with stochastic security capable of accounting for non-dispatchable and variable wind power generation sources. The principal benefit of this stochastic operation planning approach is that, when compared to a deterministic worst-case scenario planning philosophy, it allows greater wind power penetration without sacrificing security.

Reliability Issues in Photovoltaic Power Processing Systems

Abstract: Power processing systems will be a key factor of future photovoltaic (PV) applications. They will play a central role in transferring, to the load and/or to the grid, the electric power produced by the high-efficiency PV cells of the next generation. In order to come up the expectations related to the use of solar energy for producing electrical energy, such systems must ensure high efficiency, modularity, and, particularly, high reliability. The goal of this paper is to provide an overview of the open problems related to PV power processing systems and to focus the attention of researchers and industries on present and future challenges in this field.

Power Quality in Power Systems and Electrical Machines

Abstract: The second edition of this must-have reference covers power quality issues in four parts, including new discussions related to renewable energy systems. The first part of the book provides background on causes, effects, standards, and measurements of power quality and harmonics. Once the basics are established the authors move on to harmonic modeling of power systems, including components and apparatus (electric machines). The final part of the book is devoted to power quality mitigation approaches and devices, and the fourth part extends the analysis to power quality solutions for renewable energy systems. Throughout the book worked examples and exercises provide practical applications, and tables, charts, and graphs offer useful data for the modeling and analysis of power quality issues. *. Provides theoretical and practical insight into power quality problems of electric machines and systems. . 134 practical application (example) problems with solutions. . 125 problems at the end of chapters dealing with practical applications. . 924 references--mostly journal articles and conference papers--as well as national and international standards and guidelines.

Vulnerability Assessment of Cybersecurity for SCADA Systems

Abstract: Vulnerability assessment is a requirement of NERC's cybersecurity standards for electric power systems. The purpose is to study the impact of a cyber attack on supervisory control and data acquisition (SCADA) systems. Compliance of the requirement to meet the standard has become increasingly challenging as the system becomes more dispersed in wide areas. Interdependencies between computer communication system and the physical infrastructure also become more complex as information technologies are further integrated into devices and networks. This paper proposes a vulnerability assessment framework to systematically evaluate the vulnerabilities of SCADA systems at three levels: system, scenarios, and access points. The proposed method is based on cyber systems embedded with the firewall and password models, the primary mode of protection in the power industry today. The impact of a potential electronic intrusion is evaluated by its potential loss of load in the power system. This capability is enabled by integration of a logic-based simulation method and a module for the power flow computation. The IEEE 30-bus system is used to evaluate the impact of attacks launched from outside or from within the substation networks. Countermeasures are identified for improvement of the cybersecurity.

Temporary Primary Frequency Control Support by Variable Speed Wind Turbines— Potential and Applications

Abstract: This paper quantifies the capability of providing a short-term excess active power support of a commercial multi-megawatt variable speed wind turbine (VSWT) and generalizes the findings by considering different wind turbine (WT) physical parameters in a wider range from the example case. The paper also identifies some possible applications of it, in particular, in a hydro dominated system. To be able to quantify the system characteristic, a delay model of the studied hydro system is developed. Due to the fact that the initial power surge of a hydro turbine is opposite to that desired, the short-term extra active power support from a wind farm (WF) could be beneficial for a hydro dominated system in arresting the initial frequency fall, which corresponds to an improvement in the system temporary minimum frequency (TMF). The improvements in the TMF are calculated by using both the developed delay model and a detailed model, and the results show good agreement. It is shown that the WT under consideration can provide a 0.1 pu extra active power support for 10 s quite easily which is twice the Hydro-Quebec requirement.

Optimal Placement of Phasor Measurement Units for Power System Observability

Abstract: This paper proposes a method for optimal placement of phasor measurement units (PMUs) for complete observability of a power system for normal operating conditions, as well as for single branch outages. A binary search algorithm is used to determine the minimum number of PMUs needed to make the system observable. In case of more than one solution, a strategy is proposed to select the solution resulting in the most preferred pattern of measurement redundancy. The proposed method is used to benchmark the optimal PMU placement solutions for the IEEE 14-bus, IEEE 24-bus, IEEE 30-bus and New England 39-bus test systems. The proposed method is applied on a 298-bus system to determine the optimal placement of PMUs when conventional measurements are available.

Prospects of multilevel VSC technologies for power transmission

Abstract: Deregulation and privatization are posing new challenges to high voltage transmission and distributions systems. System components are loaded up to their thermal limits, and power trading with fast varying load patterns is leading to an increasing congestion. In addition to this, the dramatic global climate developments call for changes in the way electricity is supplied. Innovative solutions with HVDC (High Voltage Direct Current) and FACTS (Flexible AC Transmission Systems) have the potential to cope with the new challenges. New power electronic technologies with self-commutated converters provide advanced technical features, such as independent control of active and reactive power, the capability to supply weak or passive networks and less space requirements. In many applications, the VSC (Voltage-Sourced Converter) has become a standard for self-commutated converters and will be increasingly more used in transmission and distribution systems in the future. This kind of converter uses power semiconductors with turn-off capability.

GridLAB-D: An open-source power systems modeling and simulation environment

Abstract: GridLAB-D is a new power system modeling and simulation environment developed by the US Department of Energy. This paper describes its basic design concept, method of solution, and the initial suite of models that it supports.

Technical challenges associated with the integration of wind power into power systems

Abstract: Wind power is going through a very rapid development. It is among the fastest growing power sources in the world, the technology is being developed rapidly and wind power is supplying significant shares of the energy in large regions. The integration of wind power in the power system is now an issue in order to optimize the utilization of the resource and to continue the high rate of installation of wind generating capacity, which is necessary so as to achieve the goals of sustainability and security of supply. This paper presents the main technical challenges that are associated with the integration of wind power into power systems. These challenges include effects of wind power on the power system, the power system operating cost, power quality, power imbalances, power system dynamics, and impacts on transmission planning. The main conclusion is that wind power's impacts on system operating costs are small at low wind penetrations (about 5% or less). At higher wind penetrations, the impact will be higher, although current results suggest the impact remains moderate with penetrations approaching 20%. In addition, the paper presents the technology and expectations of wind forecasting as well as cases where wind power curtailment could arise. Future research directions for a better understanding of the factors influencing the increased integration of wind power into power systems are also provided.

Tuning and Gain Control in Electro-Magnetic power systems

Abstract: Tuning and gain control as described for magnetic power systems, including different ways to change the characteristic of transmission and reception.

Methods and systems for managing facility power and cooling

Abstract: Systems and methods are provided for determining data center cooling and power requirements and for monitoring performance of cooling and power systems in data centers. At least one aspect provides a system and method that enables a data center operator to determine available power and cooling at specific areas and enclosures in a data center to assist in locating new equipment in the data center.

Power control system for current regulated light sources

Abstract: A light emitting diode (LED) lighting system includes a PFC and output voltage controller and a LED lighting power system. The controller advantageously operates from an auxiliary voltage less than a link voltage generated by the LED lighting power system. The common reference voltage allows all the components of lighting system to work together. A power factor correction switch and an LED drive current switch are coupled to the common reference node and have control node-to-common node, absolute voltage that allows the controller to control the conductivity of the switches. The LED lighting system can utilize feed forward control to concurrently modify power demand by the LED lighting power system and power demand of one or more LEDs. The LED lighting system can utilize a common current sense device to provide a common feedback signal to the controller representing current in at least two of the LEDs.

Multilevel Diode-Clamped Converter for Photovoltaic Generators With Independent Voltage Control of Each Solar Array

Abstract: In photovoltaic (PV) power systems where a set of series-connected PV arrays (PVAs) is connected to a conventional two-level inverter, the occurrence of partial shades and/or the mismatching of PVAs leads to a reduction of the power generated from its potential maximum. To overcome these problems, the connection of the PVAs to a multilevel diode-clamped converter is considered in this paper. A control and pulsewidth-modulation scheme is proposed, capable of independently controlling the operating voltage of each PVA. Compared to a conventional two-level inverter system, the proposed system configuration allows one to extract maximum power, to reduce the devices voltage rating (with the subsequent benefits in device-performance characteristics), to reduce the output-voltage distortion, and to increase the system efficiency. Simulation and experimental tests have been conducted with three PVAs connected to a four-level three-phase diode-clamped converter to verify the good performance of the proposed system configuration and control strategy.

Review of islanding detection methods for distributed generation

Abstract: This paper presents an overview of power system islanding and islanding detection techniques. Islanding detection techniques, for a distribution system with distributed generation (DG), can broadly be divided into remote and local techniques. A remote islanding detection technique is associated with islanding detection on the utility side, whereas a local technique is associated with islanding detection on the DG side. Local techniques can further be divided into passive techniques, active techniques and hybrid techniques. These islanding detection techniques for DG are described and analyzed.

Multistate Wind Energy Conversion System Models for Adequacy Assessment of Generating Systems Incorporating Wind Energy

Abstract: Wind energy is considered to be a very promising alternative for power generation because of its tremendous environmental, social, and economic benefits. Electrical power generation from wind energy behaves quite differently from that of conventional sources. The fundamentally different operating characteristics of those facilities, therefore, affect the power system reliability in a manner different from that of the conventional systems. This paper is focused on the development of suitable models for wind energy conversion systems, in adequacy assessments of generating systems, using wind energy. These analytical models can be used in the conventional generating system adequacy assessment utilizing analytical or Monte Carlo state-sampling techniques. This paper shows that a five-state wind energy conversion system model can be used to provide a reasonable assessment of the practical power system adequacy studies, using an analytical method, or a state-sampling simulation approach.

Interdependency of Natural Gas Network and Power System Security

Abstract: This paper proposes an integrated model for assessing the impact of interdependency of electricity and natural gas networks on power system security. The integrated model incorporates the natural gas network constraints into the optimal solution of security-constrained unit commitment. The natural gas network is modeled by daily and hourly limits on pipelines, sub-areas, plants, and generating units. The application of fuel diversity (e.g., generating units with fuel switching capability) is presented as an effective peak shaving strategy for natural gas demand which could hedge price volatilities of natural gas and electric power. The proposed model can be used by a vertically integrated utility for the commitment and dispatch of generating units and the allocation of natural gas for the next day utilization. The proposed model can also be used for measuring the security of social services by modeling the interdependency of natural gas and electric power system infrastructures. If the proposed model is used by GENCOs, gas constraints will be submitted to electricity markets as energy constraints. Illustrative examples show the impact of natural gas supply infrastructure on the economic operation of a vertically integrated utility. The examples also discuss the impact of generating units with fuel switching capability on the power system security when the supply of natural gas is limited.

STATCOM Impact Study on the Integration of a Large Wind Farm into a Weak Loop Power System

Abstract: Recently, renewable wind energy is enjoying a rapid growth globally to become an important green electricity source to replace polluting and exhausting fossil fuel. However, with wind being an uncontrollable resource and the nature of distributed wind induction generators, integrating a large-scale wind-farm into a power system poses challenges, particularly in a weak power system. In the paper, the impact of static synchronous compensator (STATCOM) to facilitate the integration of a large wind farm (WF) into a weak power system is studied. First, an actual weak power system with two nearby large WFs is introduced. Based on the field SCADA data analysis, the power quality issues are highlighted and a centralized STATCOM is proposed to solve them, particularly the short-term (seconds to minutes) voltage fluctuations. Second, a model of the system, WF, and STATCOM for steady state and dynamic impact study is presented, and the model is validated by comparing with the actual field data. Using simulated PV and QV curves, voltage control and stability issues are analyzed, and the size and location of STATCOM are assessed. Finally, a STATCOM control strategy for voltage fluctuation suppression is presented and dynamic simulations verify the performance of proposed STATCOM and its control strategy.

Mitigation of Subsynchronous Resonance in a Series-Compensated Wind Farm Using FACTS Controllers

Abstract: The rapid growth of wind power systems worldwide will likely see the integration of large wind farms with electrical networks that are series compensated for ensuring stable transmission of bulk power. This may potentially lead to subsynchronous-resonance (SSR) issues. Although SSR is a well-understood phenomenon that can be mitigated with flexible ac transmission system (FACTS) devices, scant information is available on the SSR problem in a series-compensated wind farm. This paper reports the potential occurrence and mitigation of SSR caused by an induction-generator (IG) effect as well as torsional interactions, in a series-compensated wind farm. SSR suppression is achieved as an additional advantage of FACTS controllers which may already be installed in the power system for achieving other objectives. In this study, a wind farm employing a self-excited induction generator is connected to the grid through a series-compensated line. A static var compensator (SVC) with a simple voltage regulator is first employed at the IG terminal in addition to the fixed shunt capacitor for dynamic reactive power support. The same SVC is shown to effectively damp SSR when equipped with an SSR damping controller. Also, a thyristor-controlled series capacitor (TCSC) that is actually installed to increase the power transfer capability of the transmission line is also shown to damp subsynchronous oscillations when provided with closed-loop current control. While both FACTS controllers-the SVC and TCSC-can effectively mitigate SSR, the performance of TCSC is shown to be superior. Extensive simulations have been carried out using EMTDC/PSCAD to validate the performance of SVC and TCSC in damping SSR.

Design for distributed energy resources

Abstract: The blackout experiences have demonstrated the vulnerability of the interconnected electric power system to grid failure caused by natural disasters and unexpected phenomena. Changes in customer needs, additional stress due to liberalized electricity markets, and a high degree of dependency of today's society on sophisticated technological services also intensify the burden on traditional electric systems and demand for a more reliable and resilient power delivery infrastructure. This paper discusses the design of a restructured electric distribution network that employs a large number of small distributed energy resources (DER) units, which can improve the level of system reliability and provide service differentiations.

Optimal Rescheduling of Generators for Congestion Management Based on Particle Swarm Optimization

Abstract: Power system congestion is a major problem that the system operator (SO) would face in the post-deregulated era. Therefore, investigation of techniques for congestion-free wheeling of power is of paramount interest. One of the most practiced and an obvious technique of congestion management is rescheduling the power outputs of generators in the system. However, all generators in the system need not take part in congestion management. Development of sound formulation and appropriate solution technique for this problem is aimed in this paper. Contributions made in the present paper are twofold. Firstly a technique for optimum selection of participating generators has been introduced using generator sensitivities to the power flow on congested lines. Secondly this paper proposes an algorithm based on particle swarm optimization (PSO) which minimizes the deviations of rescheduled values of generator power outputs from scheduled levels. The PSO algorithm, reported in this paper, handles the binding constraints by a technique different from the traditional penalty function method. The effectiveness of the proposed methodology has been analyzed on IEEE 30-bus and 118-bus systems and the 39 -bus New England system.

Nonintrusive Load Monitoring and Diagnostics in Power Systems

Abstract: This paper describes a transient event classification scheme, system identification techniques, and implementation for use in nonintrusive load monitoring. Together, these techniques form a system that can determine the operating schedule and find parameters of physical models of loads that are connected to an AC or DC power distribution system. The monitoring system requires only off-the-shelf hardware and recognizes individual transients by disaggregating the signal from a minimal number of sensors that are installed at a central location in the distribution system. Implementation details and field tests for AC and DC systems are presented.

Demand Management of Grid Connected Plug-In Hybrid Electric Vehicles (PHEV)

Abstract: Deployment of PHEV will initiate an integration of transportation and power systems. Intuitively, the PHEVs will constitute an additional demand to the electricity grid, potentially violating converter or line capacities when recharging. Smart management schemes can alleviate possible congestions in power systems, intelligently distributing available energy. As PHEV are inherently independent entities, an agent based approach is expedient. Nonlinear pricing will be adapted to model and manage recharging behavior of large numbers of autonomous PHEV agents connecting in one urban area modelled as an energy hub. The scheme will incorporate price dependability. An aggregation entity, with no private information about its customers, will manage the PHEV agents whose individual parameters will be based on technical constraints and individual objectives. Analysis of the management scheme will give implications for PHEV modelling and integration schemes as well as tentative ideas of possible repercussions on power systems.