Do You Need an Electrical Power Management System?

You might not have to install a high-end EPMS, even if you need power quality data. Here are some options.

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Manufacturing plants are such energy hogs, but it’s often difficult for owners to implement energy conservation control strategies without the data gleaned from an electrical power management system (EPMS). The decisions aren’t based solely on energy conservation and cost savings. With the heavy machinery running at many plants, the loss of power could jeopardize safety and put employees at risk.

Whether you need an EPMS, though, depends on the level of detailed power information your facility needs. You might be able to get that information without a high-end EPMS.

Do you have to install an EPMS if you need power quality data? Absolutely not. Smart devices have the ability to store the last several events within the device—sometimes up to 30 days’ worth of information. You don’t have to integrate your high-end power meters into your online EPMS. You can decide to install meters and then extract the data from devices on a case-by-case basis.

This is exactly how one of our customers decided to use the high-end Schneider Electric meters built into their facility. Nobody collects the data from them, and they’re not integrated into an EPMS. However, if our customer ever had a power quality event and wanted to understand what happened on a detailed level, they could extract the device information by plugging the meter into a laptop.

It’s the economical best of both worlds.

If an EPMS still sounds like it’s the right solution for you, here are three options:

  1. Get an OEM EPMS. If you need higher-end energy functions, such as waveform, sag/swell detection, transient detection and harmonic analysis, it probably makes sense to integrate a proprietary EPMS. Most OEM EPMSs—such as Schneider Electric’s PowerSCADA Expert, GE’s EnerVista Viewpoint or Eaton’s Power Xpert—support open protocols like Modbus and DNP or APIs like OPC, so third-party integration is definitely possible.
  2. Just use SCADA. If you don’t need advanced analysis such as waveform capture or sequence-of-events recording, and you’re just looking for basic electrical parameters, you should use an open SCADA system to be the basis of your EPMS. You can save yourself a lot of money and a lot of complexity. Additionally, you will most likely have more options for sourcing both the software and the system integration services, which might be important if you wish to solicit competitive bids.
  3. Use a hybrid EPMS/SCADA system. If you don’t want to commit to a certain manufacturer but still need higher-end electrical analysis functionality, use an open SCADA solution like Wonderware. Then, specify intelligent electronic devices that display advanced data in a web browser. Your systems integrator can embed the web page or viewer in a frame so you can easily access the advanced data when needed.

Hybrid EPMS/SCADA case study

Affinity Energy has a customer using a Wonderware SCADA system that monitors hundreds of pieces of power and environmental reliability equipment such as generators, automatic transfer switches, uninterruptible power supplies, air conditioning units, fire alarms and leak detection.

When the system was originally specified more than 15 years ago, the owner understood the importance of being able to detect sags, swells and transients, and installed Power Measurement's Ion power quality meters with disturbance detection. Since we could not directly integrate the waveform and disturbance reporting to Wonderware, we installed Power Measurement Pegasys software (at the time, it had an easy-to-use Windows client for advanced analysis).

An operator who wanted to view the advanced meter data merely had to click on a button inside Wonderware. We scripted a command line to bring up the client software and give it primary focus on the system.

Over the years, we’ve updated the software to Ion Enterprise and embedded its web client in a frame right within Wonderware. Today, our client uses Power Monitoring Expert and the same simple methodology for accessing this advanced power analysis data.

And you know what? It works great. They are still able to use the seamless proprietary software and hardware, and can easily view it within their SCADA system.

Allan Evora is president of Affinity Energy, a member of the Control System Integrators Association (CSIA). For more information about Affinity Energy, visit its profile on the Industrial Automation Exchange.


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