Coordinated voltage control strategy in a low voltage distribution network.
| dc.contributor.author | Acharya, Parash | |
| dc.date.accessioned | 2024-08-15T22:17:36Z | |
| dc.date.available | 2024-08-15T22:17:36Z | |
| dc.date.issued | 2023 | |
| dc.description.abstract | With more Distributed Generations (DGs) and modern loads such as Electric Vehicles (EVs) installed in low-voltage networks, reactive power controllers will be required to maintain voltages at each grid point within acceptable limits. A reactive power controller connected at particular Installation Control Points (ICPs) will only maintain the voltage of the point to which it is connected. It is expected to have less effect on the other ICPs. A centralised reactive power controller within a distribution network could control the distributed sources to maintain the voltage of different ICPs within acceptable limits. This research will focus on developing a coordinated voltage control strategy through various DGs within the networks. Finally, the coordinated voltage control system will be compared with the distributed control system through various DGs. Load-flow studies are necessary to study the overall effect of a voltage controller within a dis- tribution network. A model of different power system components within a Low Voltage (LV) network was developed and used to study the voltage profile of the IEEE 13 bus system. A nodal admittance primitive (Yprim) matrix is formed for individual components, and finally, an overall Yprim matrix is developed for the network. The voltage profile of the IEEE 13 bus network is studied using the developed model of individual components. A comparison of these power-flow results was performed with the standard IEEE results. Similarly, a study of the voltage profile in a typical distribution network within New Zealand is performed. The impact of neutral voltage shift on the bus voltages is studied. Two networks were selected for the analysis, one representative of most city/commercial networks, while the other was selected randomly. Real half-hourly household load data was used to perform a power- flow analysis of these networks. A yearly power-flow analysis is performed using real half-hourly household load data for a typical city/commercial network of 46 ICPs, with 19 residential and 27 non-residential loads. Similarly, the neutral voltage shift analysis for an unbalanced load is performed for the randomly selected network. For the same network, the change in voltage in each phase due to the neutral voltage change is also analysed. This work clarifies how much of the voltage variation in an LV network is attributable to neutral point voltage shifts. Finally, voltage sensitivity analysis is performed for the typical city/commercial network using real load data for each ICP. Results show that with the same amount of injected reactive power, there is a higher voltage change at the nodes connected to the feeder with higher loads. A linearised model of VAR optimisation with the loss minimisation objective of a distribution network is developed. Loss sensitivity and voltage sensitivity matrices are derived, which are finally used in the VAR optimisation model while minimising the real power loss of the network. The network voltages are operated within the specified limit by injecting or absorbing the VAr from different parts of the network. This represents the randomly allocated DG inverters within the network, which can be used to absorb or inject reactive power. Finally, the optimisation results are presented for 46 bus typical city/commercial network representing the real distribution network within New Zealand. The result shows that the network can be operated within the specified voltage limits by injecting or absorbing the VAR from different parts of the network while minimising the losses. | |
| dc.identifier.uri | https://hdl.handle.net/10092/107383 | |
| dc.identifier.uri | https://doi.org/10.26021/15425 | |
| dc.language | English | |
| dc.language.iso | en | |
| dc.rights | All Right Reserved | |
| dc.rights.uri | https://canterbury.libguides.com/rights/theses | |
| dc.title | Coordinated voltage control strategy in a low voltage distribution network. | |
| dc.type | Theses / Dissertations | |
| thesis.degree.discipline | Electrical Engineering | |
| thesis.degree.grantor | University of Canterbury | |
| thesis.degree.level | Doctoral | |
| thesis.degree.name | Doctor of Philosophy | |
| uc.college | Faculty of Engineering |
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