Alexandros I. Nikolaidis

Loss Evaluation and Total Ownership Cost of Power Transformers—Part I: A Comprehensive Method

The key techniques employed in this paper reflect on a comprehensive method for calculating the cost of the electric power and energy needed to supply the life-cycle losses of power transformers. The method is applicable to transformer users who possess their own generation and transmission facilities. The proposed loss evaluation method is based on factors derived from relevant historical and forecasted data that are combined to determine the total ownership cost of power transformers. Finally, in a companion paper, the method is evaluated on a small-scale real system.

Indices to Assess the Integration of Renewable Energy Resources on Transmission Systems

The continuous increase on the penetration levels of Renewable Energy Sources (RESs) in power systems has led to radical changes on the design, operation, and control of the electrical network. This paper investigates the influence of these changes on the operation of a transmission network by developing a set of indices, spanning from power losses to GHG emissions reduction. These indices are attempting to quantify any impacts therefore providing a tool for assessing the RES penetration in transmission networks, mainly for isolated systems. These individual indices are assigned an analogous weight and are mingled to provide a single multiobjective index that performs a final evaluation. These indices are used to evaluate the impact of the integration of RES into the classic WSCC 3-machine, 9-bus transmission network.

Analyzing the resilience and flexibility of power systems to future demand and supply scenarios

A systematic resilience and flexibility analysis of future power systems to address the impacts of climate change and Renewable Energy penetration is becoming increasingly important, as it is expected to have a great effect on the demand and supply portfolios. Depending on the intrinsic characteristics of each power system, different aspects have to be considered in the analysis since this cannot be universal for all power systems. To highlight this, the paper presents two different case studies pertaining to the Great Britain and Cyprus networks respectively. Firstly, the resilience of the Great Britain transmission network to future demand and supply scenarios (2020, 2030 and 2050) is evaluated using a reduced version of the current Great Britain transmission network. Subsequently, the future flexibility requirements of the isolated network of Cyprus are appropriately benchmarked against future energy mix scenarios that involve conventional generation and renewable energy penetration.

Distribution loss factors for the emerging, open-access electricity market in Cyprus

The isolated power system of Cyprus is currently in a transition towards an open-access electricity market. One of the challenges that spring from this transition relates to the establishment of a transparent loss allocation method through the use of distribution loss factors (DLFs) that will be applicable in the emerging open-access market environment. To this end, this paper investigates the particulars of the DLF calculation methodology currently proposed to be used by the Market Operator in Cyprus to assess how incurred losses are allocated to all market participants. The analysis indicates that the formulation — which is currently under public consultation-, may entail hidden cross-subsidies between consumers and Distributed Generators.

Assessing the Renewable Energy Sources Integration Through a Series of Technical Performance Indices Using DIgSILENT PowerFactory DPL

The increasing penetration of intermittent energy sources in existing power systems heavily impacts the planning and operational processes of system operators. Therefore, refined approaches are required to address the techno-economic issues introduced by the stochastic nature of renewable energy sources, in an attempt to harness the maximum benefit possible. To address these challenges, this work capitalizes on a set of technical performance indices. These indices are attempting to quantify some operational impacts by providing an operational and/or long-term planning tool for assessing the renewable energy penetration in transmission networks. The modeling and simulation case studies are facilitated within the powerful grid simulator DIgSILENT which enables for fast and reliable execution of a wide spectrum of computing procedures. In particular, this chapter showcases how DIgSILENT’s programming language (DPL) is utilized to create several automated scenarios that may explore potential topologies of a test system as per the systems’ operators and planners’ possible interests.