Review of STATCOM technology and their applications in power networks

Hackett, Thomas (2017) Review of STATCOM technology and their applications in power networks. [USQ Project]


Abstract

In 2012 Ergon Energy replaced an aging Static VAr Compensator (SVC) with a Static Synchronous Compensator (STATCOM). The STATCOM in this instance could not provide the same level of network support as the previous SVC, this highlighted the fact that while in principle the STATCOM can provide various methods of compensation, they are not always designed to provide every method. More specifically, there are distinctive control system and component differences between STATCOMs depending on their required purpose. In the context of the STATCOMs evolution from a device which provided only reactive power support to both balanced and unbalanced networks, to a device that can now operate in all four quadrants this is now more important than ever. There is a need to identify the design differences between STATCOMs used to provide differing methods of network support as well as those used for large-scale Photovoltaic (PV) generation.

A literature review was conducted which details the fundamental operating principles of reactive power compensation, investigates how STATCOM technology is used to facilitate this and details the evolution of the STATCOMs role to present day operation. STATCOM operation is then categorised and the differences in control system and component design for each category are investigated and summarised. The review of the available literature highlights the need for further investigation of the DC bus design for STATCOMs operating in an unbalanced electrical network.

The methodology includes an analysis of the switching strategy used by a three-phase STATCOM with a Pulse Width Modulation (PWM) scheme. A number of equations are subsequently derived to mathematically describe this operation and the mathematical model is then implemented numerically in MATLAB. The operation and outputs of the model are tested and then verified using established power theory.

Analysis of the numerical model is then conducted using various model parameters to simulate specific network conditions. A method of calculating Total Harmonic Distortion (THD) is implemented to compare and understand how the STATCOMs DC bus responds to both increasing amounts of system imbalance and different amounts of DC bus capacitance.

The results of the simulation conclude that the presence of imbalance in the network drives different DC bus design requirements regardless of the method of compensation the STATCOM is providing. More specifically, the STATCOMs DC bus must be appropriately sized compared to the coupling inductance to allow the DC bus ripple to be mitigated.


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Item Type: USQ Project
Item Status: Live Archive
Additional Information: Bachelor of Engineering (Honours)(Power)
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
Date Deposited: 10 Sep 2021 04:50
Last Modified: 10 Sep 2021 04:50
URI: https://sear.unisq.edu.au/id/eprint/40808

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