Repository logo
 

Research Publications (Engineering and Built Environment)

Permanent URI for this collectionhttp://ir-dev.dut.ac.za/handle/10321/215

Browse

Author: search.filters.author.Kabeya, Musasa

Search Results

Now showing 1 - 3 of 3
  • Thumbnail Image
    Item
    Enhancement of solar PV output error under variable irradiation and temperature using an improved regulation strategy
    (IEEE, 2022-08-22) Akinyemi, Ayodeji Stephen; Kabeya, Musasa; Davidson, Innocent Ewaen
    A Photo-Voltaic Solar System (PVSS) is being operated in Steve Biko campus, Durban University of Technology. The energy generated by the PVSS is time varying, based on the quantity of sunlight and the temperature at which the photovoltaic (PV) cell functions. Consequently, in all situations, it is critical to obtain the full power from the PV array. The monitoring control strategy of Maximum Power Generated (MPG) from the PVSS connected to a Boost Inverter (BI) is presented in this research paper by employing an Improved Incremental Conductance and Integral Regulator (IIC & IR). The outcomes of the simulation indicate that full power can be obtained from the PV array while ensuring a consistent generated voltage under various operating scenarios.
  • Thumbnail Image
    Item
    Seasonal variation of soil resistivity and corrective factor for optimal substation earth grid design in Eastern Cape
    (IEEE, 2022-01-25) Madikizela, Andile; Kabeya, Musasa; Davidson, Innocent E.
    Optimal Substation Earth Grid Design is a vital aspect of the electrical power system protection. The Seasonal Variation of Soil Resistivity mostly influences Earth Grid Design. Due to seasonal changes, there is an annual variation in the Soil Resistivity with no known correction factors that can be utilized. This has led to a need to ascertain annual 'Seasonal Soil Resistivity Correction Factors' for utility application. The objective of this paper is to develop seasonal Soil Resistivity Correction Factors for Optimal Substation Earth Grid Design in a power distribution substation focusing on meeting the minimum safety requirements, which are the step and touch potentials. A case study site was used for this study in the Eastern Cape region based on a study carried out in the Gauteng province. Results obtained show that in winter, (June/July), the highest soil resistivity was reached and lowest value obtained in autumn season (March). The upper soil layer resistivity noticeably varies more than the lower layer. The corrective factors for the upper layer with probe spacing (0.5m-1m) is multiplied by 1.16; for the second upper layer probe spacing from (2m-5m) is multiplied by 1.02; while the lower layer with probe spacing (5m-50m) is multiplied by 1.01. The corrective factors are focused on July, which is the highest, for an Optimal Substation Earth Grid Design.
  • Thumbnail Image
    Item
    Voltage rise regulation with a Grid Connected Solar Photovoltaic system
    (MDPI AG, 2021-10-25) Stephen, Akinyemi Ayodeji; Kabeya, Musasa; Davidson, Innocent E.
    Renewable Distributed Generation (RDG), when connected to a Distribution Network (DN), suffers from power quality issues because of the distorted currents drawn from the loads connected to the network over generation of active power injection at the Point of Common Coupling (PCC). This research paper presents the voltage rise regulation strategy at the PCC to enhance power quality and continuous operation of RDG, such as Photovoltaic Arrays (PVAs) connected to a DN. If the PCC voltage is not regulated, the penetration levels of the renewable energy integration to a DN will be limited or may be ultimately disconnected in the case of a voltage rise issue. The network is maintained in both unity power factor and voltage regulation mode, depending on the condition of the voltage fluctuation occurrences at the PCC. The research investigation shows that variation in the consumer’s loads (reduction) causes an increase in the power generated from the PVA, resulting in an increase in the grid current amplitude, reduction in the voltage of the feeder impedance and an increase in the phase voltage amplitude at the PCC. When the system is undergoing unity power factor mode, PCC voltage amplitude tends to rises with the loads. Its phase voltage amplitude rises above an acceptable range with no-loads which are not in agreement, as specified in the IEEE-1547 and Southern Africa grid code prerequisite. Incremental Conduction with Integral Regulator bases (IC + PI) are employed to access and regulate PVA generation, while the unwanted grid current distortions are attenuated from the network using an in-loop second order integral filtering circuit algorithm. Hence, the voltage rise at the PCC is mitigated through the generation of positive reactive power to the grid from the Distribution Static Compensator (DSTATCOM), thereby regulating the phase voltage. The simulation study is carried out in a MATLAB/Simulink environment for PVA performance.