Semi-Rigid DG Conguration

An interesting idea still in academia though. If I were tasked with analyzing this system I would like the answers to a few of these questions:

How many installations using the Semi-Rigid concept are in continuous operation?

Who manufacturers the intelligent controller?

How much does the overall system cost to design, purchase, install and maintain?

How do the switching transients affect the plant's power quality?

Where's the inertia in the system?

What percentage of the plant load does the local distributed generation (DG) need to be supplying just prior to an event?

How does the grid operator feel about you remaining tied to him during the transient events without you providing any voltage or load support?

How does your management feel about adding additional points of failure into your grid connection?

What other more traditional steps have been taken to meet this 100% up-time requirement? Are they cheaper, more reliable, less risky, etc.?

What does it really cost if the critical systems undergo a short (you define the duration) power transient?

I'm not trying to be a nay-sayer, just thinking about the conversations I have had when evaluating high up-time critical systems for things like nuclear and fossil fueled generating systems, and process plants like refineries and synfuels. To quote Morcos and Goméz, who appear to be the first users of the term "Semi-Rigid Link" when referring to local Distributed Generation (DG) and switched series reactors, "...The task could be accomplished more efficiently and economically using energy storage equipment such a flywheel or battery bank..."

For my money I'd go with a proven technology like this and not expose my clients to something that hasn't gotten out of the lab yet.

Iám totally agree about your comment because I have had also involved to solve a guarantee stable power supply to a fertilizer plant from frequency tripping due to grid voltage dip. the solution was at that time ( 1973) using a flywheel for the control system, and reswitching the main 6 Kv busbar during one of the two lines supply failure taking as maximum time alowed of 1.2 sec. to close to prevent motor speed reduce which lead to plant trip awing to process instrument detector switch like presure switch, flow switch etc operate initiating a dangerous and complicates abnormal condition.

Thanks a lot