Transient Behaviour of Three Phase STATCOMs

Bell, Mark (2018) Transient Behaviour of Three Phase STATCOMs. [USQ Project]


Static Synchronous Compensators (STATCOMs) are becoming widespread throughout power networks due to their versatility in providing reactive and active power support. The need for this type of network support has increased greatly due to the integration of renewable energy sources. STATCOM operation can be affected by the behaviour of the network it is connected to. One important aspect of this, is the ability of the STATCOM to maintain a stable D.C. bus voltage for varying levels of system unbalance. This research investigates the behaviour of the D.C. bus voltage for varying levels of negative phase sequence (NPS) in the connection point voltage.

A state space based numerical model has been developed to allow this behaviour to be analysed. The model is constructed using a defining set of first order differential equations for each of the eight switching states of the STATCOM. Using state space solution techniques, the transient and steady state solutions for each of these states can be used to find a continuous time solution for the system. This state space technique allows the behaviour of any of the system variables to be fully described.

The successful development of a state space based model has allowed for the prediction of the D.C. bus ripple as a function of the D.C. bus capacitor size and the percentage of negative phase sequence (NPS) in the source voltage.

This model can be utilised by designers and end users of STATCOMs to assess the suitability of these devices when operating under varying network conditions.

In terms of the D.C. bus voltage, this type of analysis can be used to assess the suitability of the D.C. bus capacitors, the harmonic distortion in the inverter output and the requirements of the D.C. bus control system.

An improved understanding of the challenges faced in maintaining the D.C. bus voltage for varying network conditions will help engineers to better evaluate and define the design requirements and operational limitations of this technology.

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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: Dr Andrew Hewitt
Qualification: Bachelor of Engineering (Honours)
Date Deposited: 17 May 2022 04:18
Last Modified: 27 Jun 2023 04:46
Uncontrolled Keywords: Static Synchronous Compensators; STATCOMs; negative phase sequence; system balance

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