May LMAG Talk and Tour of Rockwell Soft Switching Technology: (Review by Dave Jensen) On May 11th, 2017, the IEEE Life Member Affinity Group sponsored a Talk and Tour
at Rockwell Automation / Softswitching Technologies, 8155 Forsythia Street, Middleton, Wisconsin. Participants numbered approximately 14, consisting of LMAG and Madison Section members. The meeting started at 5:00 PM, socializing with pizza. At 5:30 PM, Chuck Kime, LMAG Chair, introduced speakers, Dr. Bill Brumsickle and Josh Kagerbauer. Title of the talk was “Voltage Quality for Automated Processes”. Bill Brumsickle started the talk by describing a technique to detect and record short term voltage sags that can disrupt critical manufacturing processes. Then he presented a product solution called a Dynamic Sag Corrector or DySC. There are single-phase and three-phase models, but both store energy in an array of electrolytic capacitors. When voltage sags occur not exceeding 50%, a voltage doubling circuit and inverter brings the waveform back to full value without discharging bus capacitors. If voltage sags exceed 50%, stored energy from the bus capacitors is employed. There are some limitations to correction duration such as capacitor energy storage and power semiconductor thermal capacity.
Josh Kagerbauer continued with a tour of the manufacturing facility. This gave us an opportunity to see the product in various sizes and configurations in addition to the factory assembly and test stations. We learned that each DySC receives a burn-in at 40 degrees Centigrade. Banks of resistors located outdoors provide loading. Josh concluded the tour with a demo of a three- phase sag and correction on a large DySC. The talk and tour were well-received judging from questions asked and interaction between group and presenters. Meeting adjourned at 7:00 PM.
Dave Jensen, Secretary for the LMAG, has prepared a detailed report (with pictures) here and a photo collection here.
May Section Meeting Talk: (Review by CJ Gervasi) Dr. Christopher DeMarco talked to our Section about electricity markets. He explained how utilities trade power in a market of widely fluctuating prices. Power companies sell power, i.e. power (usually measured in watts) to turn on an appliance that uses the power immediately. In the future the focus may be on selling energy, as people use electricity to charge batteries in electric cars. In this case people want a certain amount of energy (Wh), but they would like to buy it at the time of night when power is cheapest.
The incremental cost of a power source is the extra costs in fuel you have to pay to get more power. Turbines typically have a spot toward the top of the maximum output where they’re most efficient. Photovoltaic and wind power have zero incremental cost because they take no fuel. This is a huge advantage, but a huge disadvantage is you cannot control the amount of power you get to respond to market demand.
The electric grid has changed over the years from a command and control model using engineering principles to a market-based economy. We generally believe that market forces should be the most efficient way to determine which source in which location should be providing power, but market efficiency depends heavily on the infrastructure. One interesting twist resulting from photovoltaic electricity is there a greater slope in the increase in demand in the late afternoon because the sun is going down at the same time people are coming home and turning on air conditioning and other high-power appliances.
We think of power as being the main product an electric company provides, much of the value is in the service of maintaining tight tolerances on frequency and voltage while efficiently moving power from various sources to consumers.