Effect of connecting shunt capacitor on nonlinear load terminals

This material is posted here with permission of the IEEE. Such permission of the IEEE does not in any way imply IEEE endorsement of any of Brunel University's products or services. Internal or personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or redistribution must be obtained from the IEEE by writing to [email protected]. Copyright @ 2003 IEEEThe use of terminal shunt capacitance has different effects on the displacement factor and distortion factor components of the power factor. These effects are considered for nonlinear loads with ideal supply, and also where the supply impedance exists but is small compared with the load impedance. Optimization of the displacement factor is found to result in reduction of the distortion factor to a minimum value

A goal programming methodology for multiobjective optimization of distributed energy hubs operation

This paper addresses the problem of optimal energy flow management in multicarrier energy networks in the presence of interconnected energy hubs. The overall problem is here formalized by a nonlinear constrained multiobjective optimization problem and solved by a goal attainment based methodology. The application of this solution approach allows the analyst to identify the optimal operation state of the distributed energy hubs which ensures an effective and reliable operation of the multicarrier energy network in spite of large variations of load demands and energy prices. Simulation results obtained on the 30 bus IEEE test network are presented and discussed in order to demonstrate the significance and the validity of the proposed method

Separated magnet yoke for permanent magnet linear generator for marine wave energy converters

In this paper the performance of a longitudinal flux permanent magnet linear generator (PMLG) for wave energy converters (WEC) is investigated. The influence of the number of slots per pole, phase q and the number of stator's winding sections are analysed. The power output and the cogging forces in the PMLG are calculated and reviewed with respect to the above design parameters. In addition, an optimised PMLG model is designed and simulated. Three-dimensional Finite Element Method (FEM) is used for solving the combined field and circuit equations of the generator.The PRIMaRE project

Handbook of Renewable Energy Technology & Systems

Worldwide, the effects of global warming, pollution due to power generation from fossil fuels, and its depletion have led to the rapid deployment of renewable energy-based power generation. The leading renewable technologies are wind and photovoltaic (PV) systems. The incorporation of this generation of technologies has led to the development of a broad array of new methods and tools to integrate renewable generation into power system networks. The Handbook of Renewable Energy Technology & Systems comprises 22 chapters, arranged into four sections, which present a comprehensive analysis of various renewable energy-based distributed generation (DG) technologies. Aspects of renewable energy covered include wind and photovoltaic power systems and technology, micro-grids, power electronic applications, power quality, and the protection of renewable distributed generation

How market regulatory framework and policy affected the CHP development in meeting 2010 targets in the UK

The future UK combined heat and power (CHP) uptake depends on the policy and market regulatory framework. Since CHP produces up to 1MT carbon savings per GW power, the UK government recognizes its role in the reduction of carbon emissions. In addition, there are the potential contributions to the security, diversity, and competitiveness of energy supply, and to provide support in a competitive manufacturing industry for sustainable energy technologies in the UK (CHPA, 2006; Defra, 2004). In 2000, the UK government announced a target of achieving at least 10,000 MWe of good quality CHP by 2010 (Defra, 2004). This article will present the existing policy and market regulations for CHP, and discuss how these issues affected CHP policy deployment for meeting 2010 targets. In addition, this article will discuss how the technology innovation, strong combined heat and power policy, and stabilized market regulations can enhance CHP development for future consideration

Technology of VAr compensators for induction generator applications in wind energy conversion systems

Many of today utility interconnected wind farms use induction generator (IG) to convert the captured wind mechanical power into electricity. Induction generator has some advantages over the synchronous generator (SG). The main advantages are its robustness and its capability to be synchronized directly to the grid. The main disadvantage, however, is its dependency on the grid for supplying its own reactive power ‘VAr’. Whether fixed or adjustable VAr systems are connected across its terminal, IG must operate at unity power factor at the rated loading while the wind power varies. With supervised control and appropriate coordination, VAr can be used to the benefits of both the wind farm developer and the hosting utility. The incorporation of today adjustable reactive power compensators such as the Static VAr Compensation (SVC) and Static Synchronous Compensator (STATCOM) with IG are vital ingredient toward a successful penetration of wind energy in today distribution grid to ensure voltage stability during the steady state and transient periods

The impact of energy awareness on energy efficiency

The increasing levels of global warming, depleting sources of fossil fuels and increasing energy costs are all having a large detrimental effect on today's society. Many efforts are being made to try and increase energy efficiency all over the world. One of the major problems is unnecessary and excessive energy utilisation. This problem has been identified by Loughborough University and they are making efforts to try and reduce energy wastage. One of their strategies, used up until recently, involved increasing energy awareness within students in halls of residence by means of a reward system called the Residential Halls Energy Efficiency League (Imago Services, Loughborough Students Union, Estates Services 2006). This scheme managed to reduce energy consumption by up to 10%, saving an estimated £9000 in only 52 days. Can those results be improved by targeting students more specifically? How much energy can be saved by increasing energy awareness

An economic robust programing approach for the design of energy management systems

Energy management systems have a key role in the operation of microgrid applications. Due to their importance, several approaches have been reported in the specialized literature. In this chapter, a novel formulation for robust optimizationbased EMS for microgrid applications. The novelty recast in the introduction of transmission constraints and in the avoidance of the use of prediction models for the uncertain variables. In this formulation, a time-variant uncertainty set is used to include the uncertainty in the optimization process. Unlike in the approaches reported in the specialized literature, the sets are previously defined based on the empirical statistics of historical data available. Thus, at each sampling time, the boundaries for the uncertain variables are obtained without using a prediction model. This reduces the complexity of the EMS making possible to compute the solution of the associated optimization problem in the range of the seconds. A modified version of the IEEE 9-bus system benchmark was used as test bench. In the modified version, the hydraulic generation unit (the largest unit in the system) was changed by an equivalent wind power station. The EMS was in charge of assigning the real power and the voltage level of the remaining two generation units