Improved Real-Power Loss Minimisation

The problem of the reactive control of a power system is formulated as a static optimisation technique to ensure the minimisation of the real-power system losses by controlling the switchable reactive power sources, generator terminal voltages, transformer tap ratios and phase shiftet's. The objective function as well as the constraints  are established using the linearized sensitivity relationships of power system state and control variables and standard linear programming routines are used to determine the optimum operating condition; the fast-decoupled load flow technique is employed because it is fast, simple and has less computer storage. Results of the application of this development to the IEEE 14 bus system is presented

Assessment of Long-Run Marginal Costing of Transmission and Distribution Expansion

The Long-Run Marginal Costing (LRMC) technique is used as a cost-reflecting pricing method and finds useful application in the recovery of the total investment cost for the use of a transmission or distribution network. This paper reviews recent applications of this technique based on some examples from United Kingdom, Greece and Oman. Then using typical practical networks as case studies, this paper compares two different methods for the determination of the LRMC of transmission and distribution expansion/reinforcement: the average incremental cost (AIC) methodology and marginal incremental costs (MIC) techniques. Based on the results obtained, it is concluded that the AIC technique is easier to implement and explain because of its price stability

Technical Note: On the Correctness of Load Loss Factor

Load Loss Factor (LLF) is a function of the estimate of the losses between the grid supply point and the consumers. It varies with voltage levels and types of consumers (such as domestic, industrial or commercial). This technical note compares the accuracy of LLF derived from exact daily and seasonal variation in demand and estimated values from the system load factor (LF).http://dx.doi.org/10.4314/njt.v34i3.1

Stochastic Fault Analysis of Balanced Systems

A sequence coordinates approach for fault calculations is extended to take into account the uncertainty of the network input data. The probability of a fault current on a bus exceeding its short circuit current is determined. These results would be of importance in determining the protective philosophy of any network. The simple 6-bus Saskatchewan Power Corporation System is used to demonstrate the features of this new development

The Impact of Distributed Generation on Distribution Networks

Distributed Generators (DG or embedded generators) are generators that are connected to the distribution network. Their advantages are the ability to reduce or postpone the need for investment in the transmission and distribution infrastructure when optimally located; the ability to reduce technical losses within the transmission and distribution networks as well as general improvement in power quality and system reliability. This paper highlights the benefits of distributed generation by using a 15-bus radial distribution network, modelled in the DIgSILENT Power Factory software, to demonstrate the improvement in voltage profile as well as the reduction in technical losses.http://dx.doi.org/10.4314/njt.v34i2.1

OPTIMAL LOCATION OF DISTRIBUTED GENERATION ON THE NIGERIAN POWER SYSTEM

The optimal sizing and location of distributed generators (DG) remain crucial factors in their application for active power loss minimization as well as voltage profile improvement. This paper describes an analytical method for the optimal sizing and placement of DG in the Nigerian power network for active power loss minimization. The effectiveness of the proposed method showed a 6.2% reduction in active power losses on the 33kV Nigerian network (i.e. from 92.7MW to 87.0MW). The results showed an improvement in the voltage profile of that six load buses whose voltages were outside the statutory limit of 0.95 pu≤ Vi ≤ 1.05pu.

A Practical Application of Low Voltage DC Distribution Network Within Buildings

Science & Technolog

Metaheuristics for Transmission Network Expansion Planning

This chapter presents the characteristics of the metaheuristic algorithms used to solve the transmission network expansion planning (TNEP) problem. The algorithms used to handle single or multiple objectives are discussed on the basis of selected literature contributions. Besides the main objective given by the costs of the transmission system infrastructure, various other objectives are taken into account, representing generation, demand, reliability and environmental aspects. In the single-objective case, many metaheuristics have been proposed, in general without making strong comparisons with other solution methods and without providing superior results with respect to classical mathematical programming. In the multi-objective case, there is a better convenience of using metaheuristics able to handle conflicting objectives, in particular with a Pareto front-based approach. In all cases, improvements are still expected in the definition of benchmark functions, benchmark networks and robust comparison criteria

A Real Test System For Power System Planning, Operation, and Reliability

Made available in DSpace on 2018-11-26T17:48:24Z (GMT). No. of bitstreams: 0 Previous issue date: 2018-04-01Nowadays, several test systems available in the specialized literature are used to verify studies regarding power system planning or network reliability. However, there are no test systems currently available with enough information in order to endorse studies that simultaneously approach expansion planning, operation, and reliability issues. This paper introduces a real test system, including the load modeling, and generation and transmission systems. The main objective is to provide all the details and information required to evaluate methods and models developed for power system planning, operation, and reliability. The presented load modeling includes hourly, daily, weekly, monthly, and seasonal patterns. Furthermore, besides the substation data, reliability details, construction costs, and characteristics of right of ways (e.g., line length, impedance, and ratings) for the transmission system are exposed. The real transmission system presented contains 39 buses, 135 transformers, and 66 lines at two voltage levels: 230 and 400 kV. Finally, the generation system reliability data as well as operation and installation costs for each unit are also provided.Sao Paulo State Univ, Fac Engn Ilha Solteira Campus, Dept Elect Engn, Ilha Solteira, SP, BrazilShahid Beheshti Univ, Dept Elect Engn, Tehran, IranUniv Tehran, Sch Elect & Comp Engn, Coll Engn, Tehran, IranSao Paulo State Univ, Fac Engn Ilha Solteira Campus, Dept Elect Engn, Ilha Solteira, SP, Brazi