A Study on Voltage Balance Control Strategy for Cascaded Multilevel STATCOM
Shruti Rastogi1, Manish Kumar Singh2
1Shruti Rastogi, Department of Electrical Engineering, BBD University, Lucknow, India.
2Manish Kumar Singh, Asst. Prof., Department of Electrical Engineering, BBD University, Lucknow, India.

Manuscript received on February 03, 2015. | Revised Manuscript received on February 09, 2015. | Manuscript published on February 15, 2015. | PP: 20-26 | Volume-3 Issue-3, February 2015. | Retrieval Number: C0806023315/2015©BEIESP
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© The Authors. Published By: Blue Eyes Intelligence Engineering and Sciences Publication (BEIESP). This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Abstract: This paper presents a study on dc capacitor voltage balance control strategy for cascade multilevel static synchronous compensator (STATCOM) and it also offers a general analytical method for balance control strategy. The focus area of concern for this study starts with the development of imbalance of dc capacitor voltage. This imbalance arises due to non-uniformity of active power consumed by chain and absorbed by it. Thus, as a solution to this problem a balance control strategy is discussed in this paper, which is based on Phase shift angle regulation. A general analytical method based on vector analysis is also presented. By this method of vector analysis the performance of Phase shift angle regulation balance control strategy can be analysed, together with its regulation capacity. To find out the importance of applying balance control strategy, a comparison assessment which is based on vector analysis between a system which is using balance control strategy and a system which is devoid of any balance control strategy is provided. This comparison comprehends that using balance control strategy is much better for the system. Another inference of comparison is that balance control strategy which is based upon Phase shift angle regulation, has the benefit of strong regulation capacity. After the comparison via vector analysis, the same comparison is done by using Simulink in MATLAB. The result of the simulations is the same as of vector analysis. The simulated data also verifies that application of a balance control strategy delivers better performance of cascade multilevel STATCOM rather than not using it.
Keywords: Cascaded multilevel, dc capacitor voltage balance, Static synchronous compensator (STATCOM), Vector analysis.