Wireless Power Monitoring Solutions

Rich Ketcham, Senior Electrical Engineer at Lord Corporation, MicroStrain Sensing Systems talks to AZoSensors about wireless power monitoring solutions.

What are the main products and solutions by Lord MicroStrain Sensing Systems?

LORD MicroStrain Sensing Systems specializes in developing solutions for test, measurement, and long-term embedded applications. There are four main divisions – Inertial Sensors, Displacement Sensors, SensorCloud, and Wireless Sensing Networks.  The inertial sensors (e.g. 3DM-GX3-45) enable industrial grade inertial measurements and navigation.  The displacement sensors (e.g. M-DVRT) are designed for high-precision linear displacement measurements.

SensorCloud is our cloud based data visualization, analytics, and reporting platform.  A Wireless Sensing Network enables synchronized telemetry from numerous sensor types and can provide a conduit for remote data storage and viewing via SensorCloud. A typical network would include several wireless sensors nodes (e.g. V-Link, TC-Link, SG-Link, etc.), an internet connected WSDA-1000, and a SensorCloud account.

Recent focus has been on the release of your new Watt-Link™, a wireless energy and power monitoring sensor node. Can you explain how this product works?

The Watt-Link is a wireless sensor node which operates within a LORD MicroStrain wireless network and measures single-phase or three-phase power. It supports our new lossless data protocol (LXRS) as well as our low duty cycle sampling mode with sample rates, which can be set between 1 Hz and 1/hr.

The LXRS^® wireless protocol Network by Lord Corporation, MicroStrain Sensing Systems.

The Watt-Link has built-in analog components used for measuring line-level voltages and supports low-voltage CTs for computed current measurements. There are several different models to support various service voltages and types (WYE and Delta). It is parasitically powered, meaning it runs off of the same line power it’s measuring. Based on the meter settings applied by the end-user and the voltage and current measurements, the meter calculates numerous other parameters relating to energy usage.

The end-user can select up to 8 values for the node to periodically report to a LORD MicroStrain gateway. The gateway then passes the data to Node Commander, our flagship PC Software, or SensorCloud.  End-users can also design their own software to control the node as well as record, analyze, and react to incoming data via our Wireless Data Communication Protocol.

How does this product provide remote energy monitoring and reporting and what type of data is recorded?

What Type of Data

The Watt-Link internally measures line-level AC voltage and measures a current though a low-voltage CT for each phase, up to 3 phases. Based on these two measurements and the phase settings (single phase, three phase, etc.), the meter is capable of deriving additional measurements for each phase including true RMS and reactive power, true RMS and reactive energy, power factor, AC line frequency, and demand among other measurements.

Provide Remote Energy Monitoring

The Watt-Link has an internal 802.15.4 wireless transceiver which can report up to 8 floating point values periodically via LORD MicroStrain’s LXRS and LDC wireless protocols.  In LXRS mode, the Watt-Link will be given a slot for collision free data transmission over the channel.

For timing and sample time-stamping, it will synchronize its clock to a beacon periodically transmitted by a gateway. LXRS mode also provides a mechanism - termed Lossless - for recovering lost wireless packets due to temporary interferers and channel fading.

In LDC mode, data is sent as soon as it’s sampled and the medium access scheme is CSMA. It is great for quickly setting up a network but the network capacity is limited and wireless transmissions are less robust against temporary interferers.

Data from the meter can be received and recorded by a computer through the use of our WSDA-Base or our WSDA-1000, both of which allow for 2 km line of sight range. With an internet enabled WSDA-1000, the end-user can control and record data from any location with internet access. In addition, an end-user can also develop a custom application to periodically poll measurement values from the meter if the 8 value limit is too restrictive.

How does the Watt-Link^TM device compare to standard and traditional energy monitoring and reporting technology that is still being used in the current market?

I think there are several differences of note. For one, the Watt-Link is capable of operating within a large, synchronized, wireless network of various sensors (temperature, humidity, vibration, etc.), which enables a more holistic view of what is being monitored.  

Many traditional energy monitoring and reporting technologies use wired buses, which require additional installation time and expense.

Some metering technologies also require third party or custom applications to visualize and act upon the data. Conversely, the Watt-Link does not have a wired bus which minimizes installation time and expense.

The Watt-Link is also compatible with our PC based software, Node Commander, and our cloud-based platform, SensorCloud. As such, it’s not necessary to program a custom software interface or purchase a third party software platform for data collection and visualization.

What changes have you seen in the industry from end-users taking on this technology?

The Watt-Link was released in June, and we are already seeing a new paradigm in energy monitoring.  Since the installation of these devices is simpler than many traditional meters and there’s a continued emphasis worldwide to reduce energy usage, we’re seeing increasing interest in the metering of individual system components.

Instead of measuring buildings as a whole, customers are sub-metering down to the machine level. There are also benefits in utilizing the entire sensing system offered by LORD MicroStrain Sensing Systems in that the end-users are now able to monitor several aspects of the unit under test with one synchronized network.

What has been their main feedback and has this encouraged room for further developments of your latest sensing system?

The feedback we have received has been very positive, and most of our customers find the Watt-Link easy to install and configure. There’s always room for improvement, however. I think the most often requested feature is higher sample rates which is something we intend to address in the future.

Some have requested we increase the available measurement count reported by the Watt-Link, which is also on the future features list.  Dash boarding for the Watt-Link is another feature that has been requested and it’s currently being offered in Beta.

So what are the main areas of application for the Watt-Link^TM cloud-enabled sensor network?

The Watt-Link is most useful in sub-metering from individual processes down to individual machines. A SensorCloud enabled Watt-Link network would allow an end-user to control and monitor the network from anywhere with internet access.

Additionally, SensorCloud is designed to handle range of data requirements from short-term, low data rate to long-term, high data rate monitoring applications. For instance, an end-user could be monitoring the efficiency of the climate control system throughout the year. As another example, a user could monitor power generation from wind turbines at several spatially distributed locations from one remote interface.

Can you describe the main advantages of the Watt-Link^TM product?

The main advantages of the Watt-Link^TM product are based on the following:

• Wireless removes the installation time and expense required to set-up wired communications with the meter.
• Parasitically powered, so there is no need to have electricians to run additional power lines to solely power the meter.
• Measurements are synchronized within the wireless network and time stamped at the node using the LXRS protocol.
• Watt-Link readily operates alongside other LORD MicroStrain wireless nodes enabling a more holistic view of what is being monitored.
• LORD MicroStrain has proven solutions available for remotely controlling the Watt-Link as well as collecting and visualizing data.

Are there any support systems in place in the event of system failure of this product?

There are a number of features at various levels of the system which help mitigate common temporary problems. In terms of safety, the Watt-Link is UL rated and contains optical isolation separating the high voltage area of the meter from the rest.

The Watt-Link preserves accumulated values such as energy sum and positive energy sum across power failures. In the event that a temporary wireless interferer is encountered, the LXRS protocol enables the wireless meter to buffer up to 200,000 samples until the communication link is re-established. If the Watt-Link is communicating with a WSDA-1000, there’s additional failure support in that the WSDA-1000 internally stores up to 1.6 GB of data.

So, in the event that an internet connection goes down, the data is still collected and can be uploaded to SensorCloud or downloaded when the connection is re-established. Data on SensorCloud is continuously backed up as well.

How much data can this system process?

The Watt-Link transmits up to 8 floating point values per second although it does monitor other values simultaneously which can be accessed using our communication protocol. Individual WSDA-1000 and WSDA-Bases can handle full networks continuously up to 6096 aggregate samples per second.

Our wireless protocol also supports a sampling mode we call burst sampling where an individual sensor node samples at a high rate (4 kHz – 100 kHz) periodically for a short duration.

Are there any major developments with any of your other key products?

We just announced the release of MathEngine at Sensors Expo where it won a Best of Sensors Innovation Award. MathEngine is an analytics platform for SensorCloud based measurement data, which enables a user to develop and run algorithms on measurements as they are uploaded to SensorCloud.

The power in MathEngine is that it harnesses the data storage capabilities of SensorCloud while offloading the processing required to our secure servers. The user no longer has to worry about storing and accessing large data sets, installing proprietary software, or building their own system to meet the processing requirements, and can now purely focus on analyzing their data and autonomously distilling actionable alerts and reports.

How do you see the products and solutions provided by your company evolving over the next five years based on the market trend and customer demand?

Customers are demanding easier ways at getting higher fidelity data more quickly and I think we’re striving to meet those demands both from the connectivity side and from the data fidelity side. This means exploring modern radio technologies that offer higher bandwidths, lower power consumption, and provide for connectivity to a variety of other devices (e.g. smart phones). It also means developing and maturing platforms that enable easy data storage and analysis, such as SensorCloud and MathEngine. There’s also increasing emphasis on smart parts which measure and report their own health statistics.

About Rich Ketcham

Richard Ketcham received his Bachelor and Master of Science degrees in electrical engineering from the University of Vermont in 2005 and 2007. He is currently a senior electrical engineer at LORD MicroStrain Sensing Systems in Vermont.

At LORD he works on the development of web-connected wireless sensing systems and optimization of embedded firmware for integrated processing and data logging. Other contributions to the field include RF propagation characterization for wireless sensor networks aboard helicopters.