Project location: Eastern Cape Municipality, South Africa
Principal Development type: SSEG
Sector: Renewables
PROJECT DESCRIPTION
In early 2021 TNEI Africa (Pty) Ltd was appointed to perform a technical impact study for a proposed 655 kWAC PV plant on a municipal network in the Eastern Cape province of South Africa.
The plant will supply the 400 V reticulation network of a shopping centre and is embedded within the distribution network of Nelson Mandela Bay Municipality (NMBM). In addition to requiring compliance to various regulations and standards, it is required by the municipality that a grid impact assessment be conducted as part of the approval process for the grid connection of the plant.
The study investigated the resulting steady-state voltage, thermal loading and fault level characteristics that could arise from the integration of the 655 kW PV plant into the NMBM distribution network. The aim was to determine whether the PV plant could have any significant adverse impact on the NMBM distribution network to which it is connected.
SERVICES PROVIDED
TNEI used the energy yield data from PVsyst and metered load data for the site to obtain representative generation and load profiles for the study. To create a conservative, worst-case generation integration scenario with maximum reverse power flow, the coincidence of maximum generation and minimum load was simulated. A 24-hour generation profile was constructed by taking the maximum envelope of the PVsyst generation profiles, whilst the load profile was constructed by taking the minimum envelope of the post-processed load data.
TNEI built the DIgSILENT PowerFactory simulation model for the SSEG with the design data and OEM inverter simulation models.
The maximum generation profile and minimum load profile were then simulated concurrently via DIgSILENT PowerFactory’s quasi-dynamic simulation tool to observe the voltage and thermal loading conditions that could arise on a hypothetical worst-case generation integration day.
BENEFITS DELIVERED
The client could see the voltages for different operational power factors on the PV system’s busbar, the existing 400 V main busbar and the 11 kV utility ring main unit busbar over the 24-hour period of the hypothetical worst-case generation integration day.
The study concluded that the PV system would not have any significant adverse impact on the municipalities network.
The municipality allowed the connection of the SSEG to commence.
