Thermal Stress Evaluation of a Multifunctional Modular Multilevel Converter - STATCOM Operating as Active Filter

• Published in: 2019 IEEE 15th Brazilian Power Electronics Conference and 5th IEEE Southern Power Electronics Conference (COBEP/SPEC) pp. 1 - 6
• Main Authors: de Sousa, R.O., Amorim, W.C.S., Mendonca, D.C., Cupertino, A.F., Morais, L.M.F., Pereira, H.A.
• Format: Conference Proceeding
• Language: English
• Published: IEEE 01.12.2019
• Subjects: Active Power Filter; Automatic voltage control; Capacitors; Harmonic analysis; Harmonic Compensation; Modular Multilevel Converter; Multifunctional; Power harmonic filters; STATCOM; Stress; Thermal stresses
• ISSN: 2643-9778
• DOI: 10.1109/COBEP/SPEC44138.2019.9065465

The Modular Multilevel Converter (MMC) has proved to be an attractive technology in medium and high voltage Static Synchronous Compensator (STATCOM) applications. Nevertheless, once reactive power compensation profile is not constant over time, there are periods that a MMC-STATCOM works below its nominal capacity. In these periods, the converter can be used to perform ancillary services, such as Active Power Filtering. This paper analyzes the thermal stresses in the capacitors and semiconductor devices (i.e. IGBTs and diodes). The analyses take into account reactive compensation and harmonic current compensation of 5 th and 7 th harmonic components of a MMC based STATCOM. In addition, the limits of harmonic compensation for 5 th and 7 th harmonic orders are analytically derived. The results demonstrated lower thermal stresses during Active Power Filtering than the traditional STATCOM operation. Moreover, the 5 th harmonic compensation is the most stressed one among the cases studied in this work.