Model an inverter system with demand response capability aligned with the framework detailed in AS 4755.1:2017 using DIgSILENT PowerFactory modelling software

Ram, Asis (2018) Model an inverter system with demand response capability aligned with the framework detailed in AS 4755.1:2017 using DIgSILENT PowerFactory modelling software. [USQ Project]


Governments are under pressure to solve the energy crisis of today and into the future by investing in cleaner sources of energy. Conventional fossil-fuel generating facilities have in the past met the majority of global electrical energy demands. However, environmental and climate change implications of fossil-fuel based generation present serious challenges to society and the environment (Obi & Bass 2016). Distributed Generation (DG), particularly Photovoltaic (PV) systems provide a means of mitigating these challenges by generating electricity directly from sunlight (Zhang, Yun, Li & Liu 2014). In 2015, the Australian Government settled on reforms to the Renewable Energy Target by setting the target for large-scale generation of 33,000 GWhr by the year 2020. This would result in about 23.5 per cent of Australia’s electricity generation coming from renewable sources by 2020 (Department of Environment and Energy 2017).

Studies have shown that the presence of DG can cause undesirable voltage rise in the low voltage (LV) networks (Roy, Pota & Mahmud 2016). Implementation of voltage rise mitigation on LV networks is more important than ever, given that distribution authorities are required to maintain voltage levels within statutory limits.

Research conducted identified various methods to mitigate voltage rise at the PV system inverter to grid point of common coupling (PCC). The reactive power – voltage (Q(U)) characteristic method has been identified as an effective method that is recommended by Australian/New Zealand Standard (AS/NZS) 4777.2 and Energy Queensland Limited (EQL) Connection Standard (2018).

A basic inverter control model is investigated in this thesis. Initially, the model simulates the network with the PV inverters performing local voltage control using Q(U) characteristics. Under this arrangement, inverters act in isolation to control the connection point voltage by reactive power injection/ absorption. The control system is then augmented through the use of a remote control device located at the supplier substation which limits power export from the inverters when local voltage control mitigation is not achieved or voltages are above statutory limits.

A PowerFactory model has been developed to simulate the practical integration of PV injection systems into a low voltage distribution network. This model allows for steady state simulation of the network for varying load and generation profiles. It also provides insight into the system stability when the integrated PV inverters operate to locally control the network voltage.

The remote controller model utilises data from the PV inverters and the solar panels. This control strategy is based on a two stage process. Initially the voltage is monitored and controlled locally by the inverters. Once the local controller voltages exceed the regulated limits, the remote controller will issue commands to the Demand Response Enabled Inverters.

The research performed here investigates the suitability of these two control strategies when maintaining distribution voltage limits.

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Item Type: USQ Project
Item Status: Live Archive
Faculty/School / Institute/Centre: Historic - Faculty of Health, Engineering and Sciences - School of Mechanical and Electrical Engineering (1 Jul 2013 - 31 Dec 2021)
Supervisors: Hewitt, Andrew
Qualification: Bachelor of Engineering (Honours) (Electrical and Electronics)
Date Deposited: 30 Aug 2022 03:41
Last Modified: 29 Jun 2023 02:29
Uncontrolled Keywords: inverter system; reactive power injection/absorption; remote control device

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