Technical Q&A

Introduction

The VarStec Technical Q&A provides practical engineering answers for medium-voltage power quality and reactive power compensation applications. Topics include power factor correction, capacitor bank design and switching transients, protection and fusing, harmonic analysis and filter design, IEEE standards and component ratings, MotorVAR™ motor starting and voltage-sag mitigation, arc-flash mitigation, commissioning, and hybrid STATCOM-capacitor systems. Organized into 12 technical chapters, the resource reflects decades of field experience and VarStec’s System-Fit design approach.

Technical Q&A Chapters

  1. System-Fit™ Engineering & VarStec Capabilities
    Defining the System-Fit™ Standard in Medium-Voltage Reactive Power Compensation
  2. Power Factor Fundamentals
    kW, kVAR, kVA, Displacement Power Factor, True Power Factor, and Medium-Voltage Power Factor Correction
  3. Capacitor Bank Design
    System Grounding, Bank Configuration, Switching Duty, Stage and Step Sizing, Protection, Controls, Harmonic Performance, and Filter-Ready Design
  4. Capacitor Switching & Transients
    Inrush and Outrush Current, Back-to-Back Switching, Current-Limiting Reactors, Restrikes, and Transient Recovery Voltage (TRV)
  5. Capacitor Bank & Harmonic Filter Bank Protection & Fusing
    Fusing, Blown-Fuse Detection, Unbalance, Overcurrent and Overvoltage Protection, Harmonic Distortion, Resonance, and Thermal Overload Protection
  6. Harmonic Analysis Fundamentals
    IEEE 519, PCC, THD/TDD, Harmonic Resonance, System Impedance, Measurements, Capacitor-Bank Interaction, and Harmonic Filter Design
  7. Medium-Voltage Harmonic Filter Design & Mitigation
    Notch, High-Pass, C-High-Pass, and H-Type Filters, Tuning, Q-Factor, Resonance Damping, and Component Ratings
  8. IEEE Standards & Component Ratings for Medium-Voltage Capacitor Banks and Harmonic Filters
    Practical Application of IEEE Standards for Capacitor Banks, Harmonic Filters, Switching, Protection, and Component Ratings
  9. MotorVAR™ Motor Starting & Voltage Sag Mitigation
    Capacitor-Assisted Starting for Large Medium-Voltage Motors, Including Voltage-Sag Reduction, Starting Torque, and MotorVAR™ Sizing
  10. Arc Flash Mitigation for Metal-Enclosed Capacitor Banks & Harmonic Filter Banks
    Fault Prevention, Arc-Energy Reduction, Personnel Exposure Reduction, and Control of Arc-Flash Effects
  11. Operation, Maintenance & Commissioning
    Commissioning, Inspection, Maintenance, Repair, Energization, and Return-to-Service Practices for Medium-Voltage Capacitor Banks and Harmonic Filter Banks
  12. STATCOMs, Capacitor Banks & Hybrid Systems
    Dynamic VAR Support Combining STATCOMs with Switched Capacitor and Harmonic Filter Banks for Fast Response and Economical Bulk MVAR