Polls

Measurement Range of Rogowski Current Sensors - R&D Project

peterjcs23 — Mon, 11 Oct 2021 15:01:43 GMT

Current Revision posted to Polls by peterjcs23 on 10/11/2021 3:01:43 PM

Rogowski Coil Current Sensors are used to measure AC waveforms, they cannot be used for DC measurements. Typically they have an advantage over iron cored current sensors at high current, as they are air cored and hence smaller and lighter than a current transformer. We have designed and made a sensor that works well at 150A full scale and higher.

The scale is set by the gain of the amplifier and we can set it up to read 20A full scale. The target is to read 5A with an error of 2%, but achieved 20%. The question is if we embark on a project to achieve 2% at 5A will there be a market for the product competing with Hall Sensor products. Here is a file that describes the Rogowski Current Sensor and the R&D project.

https://electronicsknowhowblog.wordpress.com/2015/04/22/rogowski-coil-current-sensor-rd-project/

Choose the lowest range of current for which you would use a Rogowski Coil in preference to an iron cored sensor...

Thanks for your help.

From Rogowski coil - Wikipedia, the free encyclopedia

This type of coil has advantages over other types of current transformers.

It is not a closed loop, because the second terminal is passed back through the centre of the toroid core (commonly a plastic or rubber tube) and connected along the first terminal. This allows the coil to be open-ended and flexible, allowing it to be wrapped around a live conductor without disturbing it. However, positioning of the measured conductor is important in that case: It has been shown that, with flexible sensors, the effect of the position on the accuracy ranges from 1 to 3%. Another technique uses two rigid winding halves with a precise locking mechanism.^[2]
Due to its low inductance, it can respond to fast-changing currents, down to several nanoseconds.^[3]
Because it has no iron core to saturate, it is highly linear even when subjected to large currents, such as those used in electric power transmission, welding, or pulsed power applications.^[3] This linearity also enables a high-current Rogowski coil to be calibrated using much smaller reference currents.^[1]
No danger of opening the secondary winding.^[3]
Lower construction costs.^[3]
Temperature compensation is simple.^[1]
Conventional current transformers require an increase of the number of secondary turns, in order to keep the output current constant. Therefore, a Rogowski coil for large current is smaller than an equivalent rating current transformer.^[4]

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Tags: rogowski_coil, current_sensor

Microinverters vs Inverters

ojed81 — Mon, 11 Oct 2021 14:59:50 GMT

Current Revision posted to Polls by ojed81 on 10/11/2021 2:59:50 PM

What is the best choice?

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Mains hum

neuromodulator — Mon, 11 Oct 2021 14:59:29 GMT

Current Revision posted to Polls by neuromodulator on 10/11/2021 2:59:29 PM

Probably many community members are quite familiar to the mains hum. What effect does it have on you?

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Poll: What Does the Smart Grid Mean To You?

rscasny — Mon, 11 Oct 2021 14:59:12 GMT

Current Revision posted to Polls by rscasny on 10/11/2021 2:59:12 PM

Define the 'Smart Grid.' I hear a pause. Can't do it? You are not alone.

The Smart grid means different things to different people. Some people think its about long overdue grid modernization of control and transmission assets. And other people think it's more than that. It involves the aforementioned things plus a bevy of IT-related and customer-service related (i.e., smart metering) implementations, an more. The latter is the total approach. We'll call it the IoT of electricity. So, what does the Smart Grid mean to you?

Poll Question: I've listed a number of "smart grid" innovations currently being built and/or implemented. Which one best typifies the term 'Smart Grid' to you.

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Tags: smart grid, community survey

Are You Satisfied with the Specs of the Present Generation of Low-Power Devices?

rscasny — Mon, 11 Oct 2021 14:59:07 GMT

Current Revision posted to Polls by rscasny on 10/11/2021 2:59:07 PM

Low-power, ultra-low-power, nano-power -- terms we see in just about every new product introduction, data sheet, or specifications. Clearly, the low-power spec of semiconductor devices today is critical as portable, battery-powered devices are seeing a high level of growth; this trend is expected to continue. But where are we at now? Is the current generation of low-power devices meeting your needs or do you need even lower power consumption to meet the needs of your designs? If so, what level of low-power consumption would you like to see?

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Poll: What's Your Main Interest in Power Management?

rscasny — Mon, 11 Oct 2021 14:59:02 GMT

Current Revision posted to Polls by rscasny on 10/11/2021 2:59:02 PM

Poll: What's Your Main Interest in Power Management?

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Has the time come for the decentralized power grid?

rscasny — Mon, 11 Oct 2021 14:59:00 GMT

Current Revision posted to Polls by rscasny on 10/11/2021 2:59:00 PM

In some circles, the centralized power grid most nations have is on par with the dinosaur: big, clumsy and a thing of the past.

Whether it be the excessive costs of building and maintaining a centralized power grid, the occurrence of too many power blackouts from centralized power, or the risk of hackers and other bad actors impacting its power reliability, the need for a decentralized power grid on a national scale is critical to human civilization.

A decentralized power grid can include solar, geothermal, wind, or any number of innovative renewable technologies. They can include microgrids or even what I like to call the home grid. Power is generated locally and more cost effectively.

Here's the question: Has the time come for the decentralized power grid?

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Seeking your Opinion: Is the Market Headed to Fully Electric Vehicles or 48V Hybrids?

rscasny — Mon, 11 Oct 2021 14:58:46 GMT

Current Revision posted to Polls by rscasny on 10/11/2021 2:58:46 PM

Recent news that Tesla is going to produce an all electric vehicle for $35,000 didn't surprise me that much. Sooner or later Tesla would have had to produce an electric vehicle in the price range that most people could afford.

But what really turned my head was the $ billions that Ford plans on investing electric vehicles in the next few years. GM is also responding to the electrification trends of the day and is expanding its electric car portfolio in China. And Volvo is planning on have its entire lineup electric vehicles.

But wait a minute.

Is the global market ready for full vehicular electrification?

What happened to the hybrid market?

Specifically, 48V hybrids that offer more torque, faster acceleration, and better performance than the older generation 12V hybrids, while at the same time maintaining fuel economy and emissions standards compliance.

Hybrid vehicles use a high voltage DC bus to supply power to the motor. To accomplish that, 48v hybrids use a bi-directional current/voltage converter, which is needed to provide power between the 48V and 12V batteries in a hybrid vehicle (i.e., boost 12V to 48 or buck 48 to 12). Some studies say the potential market for 48V hybrid vehicles is great, yet at the same time, some countries such as India and China expect to skip hybrid and go directly to full electric.

In your opinion, where do you think the market is moving towards: fully electric or 48V hybrids?

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Tags: scasny, power_featured

How do you Monitor your Electricity Usage?

cstanton — Mon, 11 Oct 2021 14:57:17 GMT

Current Revision posted to Polls by cstanton on 10/11/2021 2:57:17 PM

After my electricity supplier provided one of the 'smart meters' and I discovered that it outputs XML over the RJ45 serial connection, I've been looking at ways to disseminate and use this data, not to mention store it. I wondered what other people are using/doing, or if people just don't bother and rely solely on their bills?

I also suspect a device like this won't be the best way to monitor electricity usage in a 3 phase warehouse setup.

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Tags: monitoring, rj45, xml, supplier, electricity usage, power usage, electricity monitoring, power, energy, electricity supplier

set up for power plan

Former Member — Mon, 11 Oct 2021 14:57:04 GMT

Current Revision posted to Polls by Former Member on 10/11/2021 2:57:04 PM

this poll guessing the viewers and the and the responders of engineers. say yes for human power in the modern age is more worthy than any other, and no for never get the men involve.

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Tags: power

Polls

migration.user — Fri, 01 Oct 2021 13:26:24 GMT

Current Revision posted to Polls by migration.user on 10/1/2021 1:26:24 PM