How critical is process reliability to your industry?
Process reliability is absolutely critical. Machines have become pretty reliable, but motor drives have not been able to keep pace. There is a general impression that semiconductors drives, although versatile, are not as rugged and reliable. There is good news, however. Cell-based power drives possess reliability and availability close to one hundred percent.
So, what is special about cell-based drives? Cell-based drive design is the latest in the power electronics market. Multiple power cells based on low voltage IGBTs are interconnected in a modular design to provide the desired output which is good enough to drive virtually any machine. Variable frequencies are available from zero to 150 KHz. A high mark is the ability to bypass a sick cell quickly without interrupting the operation or causing transients on the line. Here are some of the advantages of cell-based power drives:
- Low Voltage IGBTs- Although the output can deliver very high voltages, a series connection of low voltage IGBTs (Insulated Gate Bipolar Transistors) with their current and speed superiority permits dozens of MVAs (mega volt-amp) at the output.
- Modular Design: The series design permits a modular nature. Only the defective module needs replacement. That makes for reduced spares cost. A module can be quickly replaced, in a matter of minutes.
- Quick Bypass: In case a cell fails to perform up to the desired level it can be bypassed in a matter of milliseconds without stopping the machine and affecting the output.
- Cell Redundancy and Continued Availability- Modular nature permits redundancy in cells. Even if a cell fails during operation, the machine remains available throughout with no effect on power or torque.
- No Emergency Shutdown- No emergency repair is required because of the combined effect of redundancy and a fast bypass. The failed cell can be replaced at next scheduled maintenance.
- Reliability- These features grant a nearly hundred percent reliability.
It is for these reasons that cell-based power drives are now dominating the industrial power solutions.
