Ultracapacitor-based ride-through system for adjustable speed drives applied to critical process

Many industrial plants rely on adjustable speed drives (ASD) for critical process applications. However, most ASD are susceptible to power disturbances, specially voltage sags and momentary interruptions. ASD tripping in industrial process can be very costly due to defective units produced as well as production down time. This paper presents an ultracapacitor-based ride-through system for adjustable speed drives applied to critical process. The complete system is composed by an unifield power quality conditioner (UPQC) and a two-quadrant chopper.