Power Quality Assessment and Mitigation

Rodan’s power systems engineering group analyze, measure, simulate, and solve electric power problems and provide training on many power quality and power system topics. Our customers include electric power utilities, institutional, industrial and commercial energy users.  We utilize a variety of enterprise power quality monitoring and energy efficiency analysis tools for electric power transmission and distribution systems.

Power quality has become increasingly important for industrial and commercial electric power customers, particularly as today’s manufacturing and control processes rely on computerized equipment which is sensitive to power system interruptions and disturbances. Rodan can provide solutions to existing power quality problems, alleviate problems that may be looming in a power system, and provide recommendations to ensure optimal power quality for facilities under construction or renovation.

Power quality problems can affect your productivity and your bottom line. We have the experience, know-how, and technology to identify, solve, and oftentimes prevent problems. Rodan’s services, including site surveys, computer simulations, and equipment sensitivity assessments are invaluable tools for improving power system performance.

Common Power Quality Problems
Three common types of power quality problems that can impact customer operations inlcude:

• Voltage Sags and Momentary Interruptions.
  Increased sensitivity of power electronic equipment, coupled with the high likelihood of voltage sags and interruptions, has resulted in these being the most visible power quality events. Adjustable-speed drives, computers, office equipment, programmable controllers, and induction heating furnaces can be extremely sensitive to these events. Typically, sags occur when there are temporary faults on the utility power system, resulting in a reduction in the voltage level. Equipment sensitivity to these events is important because nuisance tripping of sensitive industrial loads can cause equipment downtime, reduce productivity, and hurt your bottom line.
  

• Transients
  AC and dc drives, along with other electronic loads, can be very sensitive to transient voltages. The tolerance levels of these devices are often less than other loads such as standard motors. A major concern for transient voltages occurs with possible magnification of utility capacitor switching transients at low-voltage capacitor locations on customer power systems.
  

• Harmonics
  Adjustable-speed and dc drives, along with switch-mode power supplies, cause harmonic currents due to their nonlinear characteristics. These harmonic currents can combine with system frequency response characteristics to cause harmonic voltage distortion. This distortion can cause control malfunction, capacitor failures, motor and transformer overheating, and increased system losses. These problems are compounded by the use of capacitor banks, which can cause resonance conditions magnifying the harmonic distortion levels. These banks are normally installed for power factor correction purposes, as well as to free up transformer capacity.
  

When we do facility power system studies, we look at a range of specific issues, such as:

• Harmonic analysis
• Utility capacitor switching activities
• Voltage variation analysis
• Power factor correction
• Identifying and Solving PQ Problems

We use a wide range of techniques and tools to find, study, and correct power quality problems. Monitoring and field measurements are a key element in the problem-solving process. We use a combination of fixed and portable monitoring instruments to detect and analyze disturbances on both the utility and your side of the meter, as well as at key process points and other locations. This monitoring helps us to locate where problems are occurring, and determine their potential cause(s) and solution(s).

We also use computer simulations to model your power system and key connection points - utility service entrance, major systems, and backup systems.

Our goal is to prescribe a solution that is effective, cost-efficient, and won't cause problems for either you or the utility. We look at a wide range of corrective measures, including, to providing a range of cost-effective options for mitigation such as:

• Harmonic filters
• Capacitors
• K-Factor Transformers
• Power Line Conditioners
• Grounding
• Surge arrestors or protectors
• Increased line insulation
• Uninterruptible power supplies (UPS)
• Superconducting Magnetic Energy Storage (SMES)
• Backup generation