Dranetz provides a variety of consulting services expertly delivered through our sister company Electrotek Concepts.
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.Get a Quote Get More Information
Electrotek consultants 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. Electrotek services, including site surveys, computer simulations, and equipment sensitivity assessments are invaluable tools for improving power system performance.
The Smart Grid program reinforces the goal for increasing the number of renewable energy sources supplying power to the grid as well as an increasing reliance on Independent Power Producers (IPP) and standby generating capacity for peak load conditions.
As these new sources of power connect to the grid they bring with them a new set of issues related to power quality and reliability. Recognizing that both the quantity and size of renewable energy power plants are growing, there is a considerable learning experience ahead of both the grid operators as well as the owners of these renewable energy power plants.
As renewable energy power plants grow in size and number, power quality issues such as harmonics, flicker, overvoltage and frequency become important considerations. Electrotek provides a range of technical and analytical services related to renewable plants and we can assist with many power system and power quality issues. Solar arrays using inverter technology must synchronize with the grid frequency and can add to grid instability under fluctuating frequency conditions. Independent Power Producers and standby generation must be carefully coordinated and synchronized when switched into the grid.
Electrotek performs harmonic studies for renewable power plants and IPPs. Variable speed turbines that utilize power electronics can produce harmonic voltages and currents that can violate interconnection requirements. Wind plant collector systems usually include extensive underground cable systems that create harmonic resonance considerations that can lead to equipment damage. We evaluate and design harmonic filters for wind plants. In cases where inverters are use, there are concerns that they may produce harmonics and contribute to frequency fluctuations.
Electrotek utilizes its own SuperHarm™ software package to model the transmission system, the wind plant collector system, the reactive power system, and the turbine harmonic source characteristics and to model other renewable energy power plant configurations. These models allow simulation studies to be performed to determined potential problems and their most economical solutions. Electrotek also uses experience and site measurements to validate the results of the modeling and simulations.
Power quality monitoring is often done at the point of connection to the transmission system. The monitoring may be performed to evaluate compliance with power quality standards, or to troubleshoot electrical problems. Electrotek uses instruments that can store data for several weeks. For some projects, the instruments are connected to a telephone line or internet connection in conjunction with our www.powermonitoring.com service.
We evaluate individual turbines with methods from IEC 61400-21 "Wind turbines — Part 21: Measurement and assessment of power quality characteristics of grid connected wind turbines". We also monitor the point of common coupling with the utility transmission system against the IEEE Std. 519 "Recommended Practices and Requirements for Harmonic Control in Electrical Power Systems" and IEEE Std. 1453 "Recommended Practice for Measurement and Limits of Voltage Fluctuations and Associated Light Flicker on AC Power Systems."
Electrotek completed a major project that spanned several years for the National Renewable Energy Laboratory to collect information from two large wind plants in the central U.S. We also evaluate turbine electrical characteristics and monitor the collector system for unusual operating conditions.
Wind plant collector systems are prone to overvoltage conditions due to their special characteristics. We evaluate grounding transformers, station class surge arresters, and elbow style arresters on wind plant collector systems. We perform power system simulation studies of the collector system by modeling the network, turbine characteristics, and VAR compensation systems.
We utilize state-of-the-art computer simulation and analysis tools. We have expertise in a wide range of technical evaluations including electrical transient and harmonic analysis.
We use the following simulation and analysis tools
These tools are used throughout the power industry, and allow us to work with a wide range of model data formats.
Modern power systems are highly complex, and to ensure reliable performance, require consideration of all issues, probable problems and their causes, and potential solutions. Our over ten years of experience in power and distribution system studies, and our extensive track record in working with customers and their power providers to identify and solve power system problems, makes us the people to call. The PQAudit (power quality audit) can address all aspects of power quality. It focuses on common issues such as harmonic distortion, low voltage, voltage sags, wiring and grounding, and poor power factor. By using the PQAudit, you can identify potential problems, plan and take corrective measures, and prevent facility downtime, saving both time and money.
Before performing an onsite survey, it is important to review your facility's power system performance. This preliminary analysis characterizes the problem, identifies important changes to the facility or to the electric supply system (equipment or wiring changes, modifications, etc.) that could be causing power quality problems, and helps determine a plan for the site survey. Consisting of a conference call, this preliminary review sets the stage for the site survey. Thanks to our expertise, we can sometimes diagnose current or potential problems at this stage, thus reducing the need for or scope of the onsite survey and helping to focus attention where it is most needed.
Site survey & field measurements
The site survey is designed to gather information about the facility, power quality problems, and affected equipment.
Field measurements are completed in conjunction with the onsite power system and equipment inspection. Example measurement quantities include dc drive line current, bus voltages, and harmonic distortion levels, as well as power factor. Standard reporting forms are used to document all information and measurements.
Following the preliminary review and site visit, we will prepare a technical report summarizing the findings of the audit. This report will include a summary of all of the information gathered, highlighted power system problems, a summary of field measurements, suggested solutions, and recommendations for follow-on power system monitoring or engineering analysis. This report introduces you to the scope and nature of any problems, and provides an excellent foundation for more analysis and effective power system design.
All at a Reasonable Cost
The PQAudit package is reasonably priced — at a fixed cost. There are no unexpected fees or mysterious "other’ professional services. Additional analytical or engineering services are available on a quotation basis.