F. R. Islam

Design a PV-AF system using V2G technology to improve power quality

This paper presents the use of PHEVs with photovoltaic sources as an implementation of Vehicle to Grid (V2G) technology for designing a photovoltaic shunt active filter (PV-AF) system to improve power quality of photovoltaic generation. A system model with photovoltaic generation and a dynamic model of PHEVs are introduced here based on third order battery model. A simple battery scheme is proposed for the control of the charging and discharging of the PHEVs using a power electronic interface. The active filter controller is designed based on the instantaneous power theory (p-q theory) to improve the PV cells performance. Simulations have been carried out and demonstrate that PHEVs have the potential to work as an active filter of photovoltaic generation to improve power quality, dynamic power factor correction and harmonics current compensation.

PHEV's park as a virtual active filter for HVDC networks

The HVDC converters used for rectifying or inverting operations absorb reactive power from the converters connected bus. Compensation of reactive power in AC side of converters is quite necessary in either case of operation. On the other hand the nonlinear behavior of power electronic converters produces harmonics in both sides of HVDC links. Passive and active filters are used to filter the harmonics. Due to the increasing interest in HVDC links, the reactive power compensation and harmonic reduction method should be improved but this increases the total cost along with the hardware complexity and control strategies of the links. In these circumstances the implementation of Vehicle to Grid (V2G) technology is used to design a shunt active filter system to improve power quality of HVDC link. The active filter controller is designed based on the instantaneous power theory (p-q theory). Simulations have been carried out which demonstrate that PHEVs have the potential to work as an active filter of HVDC to harmonics current and reactive power compensation, as a result improve the power quality.

V2G technology to design a virtual UPFC

Unified Power Flow Controller (UPFC) is a FACTS device which can fulfil multiple power flow control objectives such as needs of reactive shunt compensation, phase shifting and series compensation. However UPFCs are quite expensive and therefore are not widely used. In this paper the potential of Plug in Hybrid Electric Vehicles (PHEV) in a V2G mode of operation is explained, which gives a low-cost solution for designing a virtual UPFC using PHEV charging station. A third order dynamic battery model is used here to represent the PHEV. Simulations have been carried out and demonstrated that PHEVs have the potential to work as a virtual UPFC to improve power quality.

Impact of dynamic PHEVs load on renewable sources based distribution system

In this paper, charging effect of dynamic Plug in Hybrid Electric Vehicle (PHEV) is presented in a renewable energy based electricity distribution system. For planning and designing a distribution system, PHEVs are one of the most important factor as it is going to be a spinning reserve of energy, and also a major load for distribution network. A dynamic load model of PHEVs is introduced here based on third order battery model. To determine the system adequacy, it is necessary to do a micro level analysis to know the PHEVs load impact on grid. Scope of such analysis will cover the performance of wind and solar generation with dynamic PHEVs load, as well as the stability analysis of the power grid to demonstrate that it is important to consider the dynamics of PHEVs load in a renewable energy based distribution network.

Design a Unified Power Quality Conditioner using V2G technology

Unified Power Quality Conditioner (UPQC) can fulfil multiple power quality control objectives such as needs of reactive power compensation, voltage flicker and harmonics current compensation. However UPQCs are quite expensive and therefore are not widely used. In this paper the potential of Plug in Hybrid Electric Vehicles (PHEV) in a V2G mode of operation is explained, which gives a low-cost solution for designing a virtual UPQC using PHEV charging station. A third order dynamic battery model is used here to represent the PHEV. Simulations have been carried out and demonstrated that PHEVs have the potential to work as a virtual UPQC to improve power quality.

Integrating Smart PHEVs in Future Smart Grid

In a smart power network, PHEVs can act as either loads or distributed sources of energy. The two terms most commonly used to describe the interconnection of a power network and electric vehicle are `Grid-to-Vehicle (G2V)’ and `Vehicle-to-Grid (V2G)’. When electric vehicles are connected into the grid to recharge their batteries or supply energy to it, they act as loads known as the G2V or V2G modes of operation respectively. This chapter reviews the impact of implementing the G2V mode, and the benefits and drawbacks of, and strategies for, the V2G interfacing of individual vehicles with a PHEV park. The performance of a power system network can be improved using V2G technology, which offers reactive power support, power regulation, load balancing, and harmonics filtering, which in turn, improve its quality, efficiency, reliability and stability. To implement V2G technology, a power network might require significant changes in its structure, components and controls, the issues for which include battery life, the need for concentrated communication between vehicles and the grid, the effects on distribution accessories, infrastructure changes, and social, political, cultural and technical concerns. As storage is essential for a power system, distributed electric vehicles can be an economical storage solution if it has a good plan for buying and selling its energy. Bidirectional power flow technologies of V2G systems need to be addressed and the economic benefits of V2G technologies depend on vehicle aggregation and G2V/V2G strategies. In the future, it is expected that their benefits will receive greater attention from grid operators and vehicle owners.

Method, impact and rank similarity of modified centrality measures of power grid to identify critical components

Modified versions of betweenness and closeness centrality measures are proposed to identify and rank critical nodes in power systems. Power flows in various lines of a transmission system are taken as weighting parameters to calculate betweenness and closeness centrality measures. Changes in measures of impact like path length, connectivity loss and size of blackout are observed when nodes from the nominal system are removed one by one. Test results show the efficacy of proposed modified method because of severe effect found on measures of impact. Rank similarity analysis is carried out on Australian test system in six different operating conditions to validate that critical nodes do not change the order of criticality even though system loads and generations are varied in a wide range.

Modified centrality measure based on bidirectional power flow for smart and bulk power transmission grid

A centrality measure has been proposed considering the directionality of power flow of future smart grid. Applicability of the proposed method has been evaluated in several standard IEEE test systems. Various comparisons are shown between impacts of removal of critical nodes found from two different models: nondirectional and bidirectional. Larger impact of removing critical nodes found from bidirectional flow model shows the utility of the proposed method. Measures of impacts considered are changes in path length, loss of connectivity and load lost during cascade.