Essex STATCOM Upgrade - Engineering, Testing and Commissioning

摘要

Vermont Electric Power Company Inc. (VELCO) installed a unique voltage sourced converter (STATCOM) at its Essex Substation in 2001 as shown in Figure 1-1 to provide continuous steady state voltage regulation, dynamic system voltage support and power quality improvement in the Chittenden County area in the state of Vermont, USA. The Essex facility operated without any extended major forced or scheduled outage after the original GTO inverters were replaced with GCT inverters in late 2002 [1]. However, there were significant concerns due to the aging control system hardware and obsolescent software while at the same time there were more stringent reliability and availability requirements associated with significant additions of renewable generation including both wind and solar farms in Vermont. In 2014, VELCO performed a detailed technical assessment to evaluate the condition the facility to explore options to extend its useful life and improve its performance. The details and outcome of that assessment have been described in paper [1]. A major refurbishment project was initiated in July 2015 primarily to address the issue of the obsolete PLCs, and HMIs. However, in the interest of improving overall reliability and performance, the original six inverters, control and protection systems, cooling systems, and some of the auxiliary equipment were replaced as well. This paper covers the scope of the upgrade project, key aspects of engineering design, factory testing of the major equipment and control/protection systems as well as the commissioning of the upgraded facility. The paper also summarizes the equipment and performance improvements compared to the original STATCOM.