2012 was a historic year for the U.S. solar industry. There were 3,313 megawatts (MW) of photovoltaic (PV) capacity installed throughout the year, which represents 76% growth over 2011’s record…
Power Quality White Papers
Power quality white papers on Power Quality.
209 white papers in Power Quality
Techniques for Analyzing Motor Startups
This paper covers the setup fundamentals and techniques required to obtain the high-quality waveform capture needed to analyze a motor startup. It also reviews the basic electrical characteristics of a…
Defining Interharmonics
Interharmonics are frequency components at non-integer harmonics of the line frequency. The proliferation of large DC-converter variable speed drives and wind/solar inverter generation has led to an increase in interharmonic…
Three-Phase Motor Start Causes Voltage Dips
In many cases when a local utility customer complains of voltage problems, it can often be traced back to a neighboring electrical load change that has caused voltage dips on…
Understanding Telephone Interference Factor
Harmonic distortion that is produced from power conversion systems can cause interference on analog telephone lines. The degree of telephone interference can be expressed in terms of the Telephone Interference…
CBEMA and ITIC Curves
The CBEMA and ITIC curves are both used to visibly represent voltage events. The terms and associated curves are used somewhat interchangeably even though there are subtle differences between the…
Voltage and Current Out of Limits Reports
This white paper covers Out of Limits Reports, their main benefits, and how and when to use them. Out of Limits Reports offer a quick way to gauge power quality…
Measuring Frequency with PMI Recorders
Line frequency is the most tightly controlled parameter in the electrical distribution system. Since almost all generation in a region is connected essentially in parallel, the frequency is inherently synchronized…
Daily Profile Graphs in ProVision
Daily Profiles are used to spot daily trends in voltage, current, power factor, etc. An entire recording session is combined to form the "average" 24-hour day, which is then plotted…
Arithmetic vs. Vector Power
The basic formulas for RMS voltage, current, power, etc. in a simple single-phase circuit are well-defined and universal. For polyphase systems, the situation is more complex: in the 3-phase delta…
Computing Event Duration with Histogram Data
The cycle histogram is an important, but underused record type available with all PMI recorders. The histogram doesn't require any configuration, spans the entire recording session (no possibility of memory…
Measuring Voltage Unbalance
Voltage unbalance can cause severe heating in motors and large DC power converters and an increase in harmonic currents. Fortunately unbalance is easy to measure with PMI recorders and ProVision…
