Search

The lack of access to clean and affordable energy supply is one of the factors affecting people's socioeconomic life and well-being in several local communities in Nigeria. This has birthed several other issues such as a lack of potable water, good healthcare service, etc. Therefore, this paper presents the techno-economic design and analysis of wind power-based water pumping systems, considering the average daily wind speed of a location in Ikeja, Lagos, Nigeria. The wind potential was modelled using a two-parameter Weibull distribution to determine its viability for water pumping in the location. Five 25-kW, pitch-controlled wind turbines (WT1 - WT5) from different manufacturers with dissimilar characteristics were examined at varying hub heights. The annual energy generated, the cost of energy (COE) and the cost/m³ of water produced (Cunit) were then evaluated. The results indicate that WT3 has the least COE ranging from $0.03/kWh to $0.13/kWh and Cunit ranges from $0.003/m³ to $0.012/m³ for hub-heights of 10m to 50m, while WT5 has the highest COE ranging from $0.011/kWh to $0.64/kWh and Cunit ranges from $0.011/m³ to $0.063/m³ for hub-heights of 10m to 50m. The results further reveal that the proposed system is more economically viable than the public utility system. [ABSTRACT FROM AUTHOR]

In this paper, the influence of the Static Var Compensators (SVC) on distance relay protection when connected to the sub-transmission network of the Nigerian 132-kV grid system is investigated. This is carried out by monitoring the error margin of the fault locator associated with the distance protective relays when SVC is connected to the transmission line. The location of the SVC is selected such that there is a common primary source of power to the subtransmission network (Ikorodu-Sagamu 132-kV transmission line) and the SVC, which is a shunt-connected device located on Ikorodu 132-kV bus. The fault is simulated at 33.6 km and 60.4 km respectively from the Ikorodu 132-kV sub-station in MATLAB/ Simulink model and the simulation results obtained are used to investigate the influence of SVC on distance protective relay when connected to the 132-kV power transmission line. The results of the line faults are obtained with respect to earth for both zones one (1) and two (2) when SVC is connected and disconnected for all shunt type of faults. Thus, indicating under-reach and overreach characteristics of the distance relay, when the SVC is connected and disconnected, while the transmission line protection showed no under-reach or over-reach characteristics for line-toline fault for both zones with the SVC connected or disconnected. The results of this study show that though SVCs improve the quality of power to consumers, there is a tendency for underreach and over-reach characteristics of the protective relay to be displayed when the relays are disconnected and connected, which introduces error margins to the fault locator in distance protective relays. Therefore, more detailed dynamic simulations are recommended for reducing the error margin. [ABSTRACT FROM AUTHOR]

Reactive power compensation on radial distribution systems is a challenging issue. Electric power distribution systems are being bedeviled by high active power loss and severe voltage violation especially on the buses that are far from distribution substations. This article presents a two‐stage approach for sizing shunt capacitors and identifying the locations where their placement would be most beneficial within radial distribution systems. A multiobjective function capturing real power loss minimization and bus voltage profile enhancement was formulated and weighted approach was engaged to transform the function into single objective one. While backward forward sweep approach was used for the load flow analysis, loss sensitivity factor was employed to predetermine suitable sites for capacitor installation, with the optimal sites and sizes determined using cuckoo search algorithm. This approach was implemented on IEEE 15‐bus and Yale 17‐bus/11 kV feeder. Results obtained using the method was thereafter compared with those obtained through other methods as obtained from literature and the comparison shows that cuckoo search algorithm outsmarts others. Significant reduction in real power loss, coupled with appreciable enhancement in voltage profile, is achieved on the Yale 17‐bus/11 kV feeder. The approach is therefore viable for addressing reactive power compensation problems confronting practical radial distribution systems. [ABSTRACT FROM AUTHOR]

Increase in geometrical trend in the demand for electrical energy, in addition to large interconnections, has increased the operational and structural complexities of modern power systems. Improved performance in modern power systems as well as enhanced reliability without sacrificing the integrity of the network at a minimum operating cost is, therefore, of great concern to power system utilities researchers and engineers. In addition, there has been a rapid development in the integration of renewable energy sources into the conventional power systems and various hybrid generating plants, in modern power systems, have emerged. In solving the EDP in modern power systems, due to the existence of non-convexity in the problem, the capability derived in the meta-heuristical-based methods have been extensively explored in recent times. This paper, therefore, presents a comprehensive review of various meta-heuristic approaches through which the solution to economic dispatch problems could be effectively provided. [ABSTRACT FROM AUTHOR]

This paper presents an alternative approach of Inherent Structural Characteristics Theory (ISCT), for solving loss allocation to network participants as well as generation-to-load matching problems in a deregulated environment. The mathematical formulations of ISCT, based on the fundamental circuit theory laws, are revisited. A Generation-to-Load Allocation Coefficient (GLAC) matrix for solving generation-to-load allocation and network loss allocation to load problems, for efficient transmission pricing, is formulated. The allocation of real and reactive power contributions, by individual generator, required to serve the network demands is also determined on the basis of the GLAC matrix. Total network losses are determined and allocated to individual network loads based on GLAC matrix. The approach is demonstrated using the standard IEEE 30 bus network. The results obtained are compared with that obtained using graph theory approach based on the solved power flow. The comparison of the results shows that the ISCT approach is reasonable and it is a good signal, which could be useful for pricing of electricity by the market regulators. [ABSTRACT FROM AUTHOR]