Transcript

Introduction to Event Capture and Analysis

Good afternoon, everyone, and welcome to today’s white paper webinar. Today, we will be discussing event capture and specifically how the event capture record can be analyzed with Merlin to provide a more complete and robust overview of a PQ investigation.

The white paper here is going to talk about setting up event capture, what event capture is, how Merlin™ works, and the different pieces of the Merlin output that you’re going to find in the event capture.

What Is Event Capture?

To summarize what event capture is, event capture is basically a poor man’s waveform capture. The early PMI recorders didn’t support waveform triggering, so you wouldn’t get triggered or periodic waveform captures, which are obviously much more high-resolution data than what you get with these event capture. The point of the event capture was to track and record a point of interest during a recording session.

You’re able to configure it to have a series of parameters. For example, if you go down here and look at how this one was configured: when you have the nominal voltage plus or minus six volts, so whenever the voltage would fluctuate by plus or minus six volts, you get an event change record that was triggered. It will show you the minimum and maximum voltage during that period, the same with the current, and then the previous and post-values for each one of those.

So, it’s telling you that before this, the current was zero amps, went up to 1.7 amps, and that triggered a voltage drop of about six-and-a-half volts or so. And you got a handful of these records to tell you the duration was 40 cycles, 13 cycles, 22 cycles, a little under a second, a little over a second. Some of these are longer, some of these are shorter.

Event Capture vs. Waveform Captures

The event capture is a very high-level, low-resolution view of excursions basically for voltage and recording. It doesn’t provide the same resolution as waveform captures, which all the modern PMI recorders do provide. While we still do record the event captures, kind of like a free ride-along that comes with the waveform captures with all of PMI’s new modern recordings.

What makes this distinct is that in an individual recording, you can go in and look at each individual record and you can see the time of day, but this is just a lot of data to present to a user. It’s a lot of tabular data, lots of columns and rows and values that can get overwhelming, especially on a longer recording with a lot of events.

In this case, we have four waveform captures, which have conveniently been pre-classified with Merlin™ as a juxtaposition, looking at our record here on the event change, and you can see the min and max and then the previous and posts. But with the waveform captures, we get obviously much more data. You can look at the voltage and waveform sine waves as they’re occurring during the triggered event, and we can look at the RMS for that, and you can see the SAG and the RMS voltages and then the increase in the current. So, it’s clearly a load-driven SAG.

Event Change Records as Part of a Holistic PQ Overview

The point of this paper was to talk about how even though the event change records are not providing a whole lot of information on their own, they can be used as part of a holistic overview into the entire PQ recording session.

If you have Merlin, which is our PQ analysis software that rides on top of PQ Canvas, we have a power quality report, which is a high-level overview, but also with a lot of executive details about what happened over the course of the entire recording session. And a not insignificant part of that is based on the results that came from the event change.

If you look at the power quality report, you can find the PQ history matrix, and we’ll find both the sags, swells, loose neutrals, and flicker. We don’t have much rapid voltage changing here. But the voltage sags here, the severity seven, that is going to be coming from both the waveform captures, the strip charts, but also from the event change records that we saw before from PQ Canvas.

Merlin’s Event Change Report

When you come into Merlin, we have the event change report, which actually is going to be a whole overview of all the event change records that were recorded in this session. What it’s really good at is picking out high-severity events and being able to cluster those.

We’ll see here, we have two SAG groupings. What this can do very quickly without the human having to look at it, it’s going to tell you that these events are occurring on this date and time over this period of time, and it’s going to give you an overview of what the event was based on the event capture records themselves.

All of this information, everything from the executive summary, which is your brief three-paragraph overview of what it got from those, I think it was 15 event change records, and then it highlights your high-severity events. All of that comes back into and gets fed into the power quality report and is part of our overview for SAG.

When we have voltage SAG, this is feeding from the waveform captures, from our compliance report output, and from the event change output. It’s a very useful record to have. Like I said, it does not take up a lot of recorder memory, so if you do not have a recorder that’s streaming continuous to PQ Canvasa, these records are very lightweight, so to speak.

Turning them on and having them record and setting some thresholds is a really good, efficient way to grab a lot of really useful events. If you’ve got a PQ investigation that has a lot of things going on, the event change report is a really good way of just isolating specifically the things we have rapid or large shifts from the steady state of the system.

Navigating Event Change Reports in Merlin

With that, I’ve got Matthew here, who wrote this paper, and I’m going to have him go ahead and walk you through the overview of how you can get into Merlin™ and how this process works and how you can get in from PQ Canvass to look at the event change reports.

Here’s the page you get to when you select one of your recordings you have uploaded. Usually, we could go down here to these event chains, as we were shown earlier. These are all the raw data that Merlin™ uses to do its analyses. But if we go back to this main page, up in the top left, we have a little Overview button. This will bring us to the Merlin™ homepage.

This has our color report, the focus areas, the compliance, and down here at the bottom is the Event Change Report. This is specifically focusing in on those event changes for those triggers that we set setting up the device. And this has summaries, like we were saying, of just the executive summary of the kind of overview of everything, specifically high severity.

This focuses on compliance. This one kind of summarizes the events for you. It even tries to guess as to what the cause might have been and who’s responsible for the event. It even tells you what you can do to investigate further. It’ll suggest things like, “Oh, you should change the values for the other triggers to find something later.” And then also, it has some more advice to what you could do, as well as next steps in your investigation that might help.

High Severity Events, Compliance, and Attribution

That’s actually a really good point. One of the more interesting pieces here of what Merlin™ will do for you is it will identify high severity events, and it will tell you whether or not you’re within compliance for a series of different IEEE and IEC standards.

Attribution is a big piece, and again, it’s been extremely accurate in the cases we’ve run so far. We’ve done this with a handful of customers who’ve been working with us over our beta program, and the attribution will help identify is this something on the utility side, or is this load-driven by the customer? Is the customer responsible for what’s happening here? And it does a pretty good job at identifying that and identifying what the load is in addition.

Providing Context to Merlin™ Before Analysis

With Merlin™, when you start an analysis—this recording that we’ve done here has already been executed, but when you start an analysis, you can give it a lot of input, so that when it’s making its decisions and it’s coming up with a report, it can take any inputs you gave. Like, hey, this is on a customer. He’s on his own isolated transformer because he owned the customer on this feeder. And so he is complaining about light flicker. We suspect that it’s load driven from the customer. It’s a bad heat pump, or something along those lines. So you can kind of prod Merlin along before the analysis, so it has that in its context before it even starts.

Summary of Events, Patterns, and Multi-Trigger Events

Of course, we have the summary of all events, so again, this goes back through and tries to tie everything together just from the event capture record, and then patterns and likely origins, where it’s going to try to tell you what was the cause of what we were seeing here with rapid voltage change or sags.

The closely spaced and multi-trigger events are really useful for helping the utility diagnose what’s going on. If you are in dialogue with the customer, you can identify time of day. Hey, were you home during this period? Is this something that you might have been at home and had this large two-phase load? Is this when you get home and plug in your EV, or is this some other event that might have been caused by you to help investigate and diagnose what that is?

Using Merlin™’s Chat Feature

One of the other things that’s very useful, because as you can see here, there’s a lot of information that Merlin™ is giving you across the board—individual shift chart records, waveforms, the event change, specific focus areas, our compliance report output, and then the digest. And that can be a lot of information to digest.

So, one of the things we have, it’s in beta right now, is a chat that you can do with Merlin™. You can ask Merlin™, “Hey, tell me what’s going on. Make it a high-level overview. Tell me what the most important things in this recording are, and what do we need to do in order to proceed?” Then it’ll think about that for a couple of seconds. It can give you a nice overview.

Document Writer for Customer and Engineering Communications

In addition to this, if you’re working with customers, let’s say we determined that this is not on the utility’s fault, this is certainly load driven at the customer’s location, we have a document writer. That will help you, the PQ Canvass user, to craft a letter to explain to the customer what’s going on.

You can also have it craft documents like short notes for the local engineering team, your PQ engineering team. And you can have it write reports for regulatory compliance or compliance agencies if you need to. There are several different templates that you can choose from, where you can specify the technical rigor of what’s being included in that output report.

Example Document Output

Immediately, it points out right here that it’s well-regulated 120-volt three-phase service with two customer-driven equipment starts that cause moderate sags, but brief harmonic spikes and some oscillatory transients. So, outside of those episodes, voltage, balance, and distortion, all very good, and there are no interruptions or swells. The two sequences line up with a flicker event and exceedances.

The background PQ conditions are very good voltage regulation. Three-phase imbalance is low. Neutral looks healthy. A few common mode steps, so very low current. The attribution: start from very low, with sag depth closely proportionate with the current. No significant voltage disturbances with concurrent local current changes. So, that’s already telling us a little bit about what it’s going to tell us.

One or more customer three-phase devices, likely with a magnetic inrush stage followed by a non-linear electronic stage is the primary source. So, it’s telling us right here that all the signs are pointing to this being a customer-driven load.

Again, when I was talking earlier about finding events, we got dates and times. It’s going to tell you, here’s some times to look at. What was going on at these dates and times? Were you home? Can you see what was going on? Do you have three-phase motors, transformers, power electronics systems at home that might be causing this?

Document Writer Templates

So, that’s just a real quick example of what Merlin™ can do. You can take this chat output. We’ve got the document writer. I’m going to say, a general PQ report, customer letters in here, technical summary, executive summary, non-technical customer letters—so you can have it write a brief letter to the customer explaining to them what we found as a utility and what our responsibility is and what their responsibility might be and what we can recommend.

An engineering deep dive—if you want a really good, multi-page detailed engineering analysis, this will give you that. And you can save it as a PDF, export it, pass it around the engineering team, et cetera.

Wrap-Up

All in all, the event change records themselves are useful, even without Merlin™. There’s good data that’s in there. But when it’s combined with Merlin, when Merlin can ingest that and take a holistic, whole PQ investigation overview and roll that in together and give you a report is where these event change records really shine.

Well, I think that covers just about everything. If you have any questions, feel free to type them in the question box over here, and we’ll see if we can get those answered.

Okay. Well, it doesn’t look like we have any questions today. If you do think of any questions after the session ends, feel free to call our technical support at 800-296-4120. That’s 4-1-2-0, or you can send an email to support@powermonitors.com. Thank you everybody for joining, and we will see you next week for next week’s white paper webinar.