Waterloo, Ontario, July 2016. A frequently asked question during Printed Circuit Board (PCB) layout review meetings is, “Are 50-ohm traces being used for the digital signals in this PCB layout?” Often the answer to this question is “yes”. However when making decisions that balance cost, performance, and manufacturability the correct answer can also be “no” or “not for all the digital signals”. Alternative approaches can include focusing on the “controlled impedance” of PCB transmission lines and/or using other trace-impedance values.
Let us examine a layer-stack design and see how the PCB trace width affects layer count (cost) and trace impedance (performance). In Figure 1, routing channels of the same width are shown on a signal layer for three PCB transmission lines: a 100-ohm differential pair, a 50-ohm and 60-ohm single-ended.
Figure 1: Routing channels of the same width are shown on a signal layer for three PCB transmission lines for a 100-ohm differential pair, a 50-ohm and 60-ohm single-ended
The 100-ohm differential-pair is usually determined prior to the single-ended and should be fitted in the routing channel (between the vias) without discontinuities because they are usually for higher speed digital signals. Once the trace width and spacing of the 100-ohm differential-pair have been designed, the trace width for 50-ohm or 60-ohm single-ended on the same layer is usually determined accordingly. Changing the trace width alone for the single-ended traces will lead to different trace impedance. The trace routing yield per channel is:
Right: One 100-ohm differential-pair with 4mil trace / 5.5mil space.
Middle: Two 60-ohm traces for single-ended with 4mil trace / 4mil space.
Left: One 50-ohm trace for single-ended with 6.5mil trace / 7.4mil space.
Note: This example assumes that the minimum trace width and spacing are 4mils.
In this case, the engineer needs to make trade-off decisions on using either 50-ohm traces, which use up more PCB space and possibly more layers, or 60-ohm traces which use up less PCB space and possibly less PCB layers.
“Nuvation’s attainment of Draft 3 conformance streamlines the integration of their battery management system with Parker’s MESA-compliant inverters and 3rd-party site controllers on the Alevo GridBank project. As a founding member of MESA, Parker views Nuvation’s adoption of MESA standards and their ongoing involvement as an important step in simplifying the integration of Nuvation BMS into energy storage systems.” – Daniel Friberg, Division Engineering Manager, Parker Hannifin
Nuvation Grid Battery Controller (on right), managing multiple battery stacks in a 2MW/1MWhr Alevo GridBank energy storage system
Sunnyvale, California. June 6, 2016. Nuvation Engineering has announced that their battery management system for large-scale energy storage systems (ESS) is now conformant with Draft 3 of the MESA-Device/SunSpec Energy Storage Model. “MESA Draft 3 conformant products share a common communications interface that exposes all the data and control points required for operating the energy storage system,” said John Corman, Vice-President, Engineering and Product Management at Nuvation. “Nuvation BMS can now be integrated with any other MESA-conformant energy storage hardware or software without the custom middleware often required to enable different companies’ products to work together.”
“Nuvation’s attainment of Draft 3 conformance streamlines the integration of their battery management system with Parker’s MESA-conformant inverters and 3rd-party site controllers on the Alevo GridBank project,” said Daniel Friberg, Division Engineering Manager, Parker Hannifin. “As a founding member of MESA, Parker views Nuvation’s adoption of MESA standards and their ongoing involvement as an important step in simplifying the integration of Nuvation BMS into energy storage systems.”
Novi Michigan, April, 2016. Alevo has selected Nuvation BMS™ to manage their lithium-ion based GridBank containerized energy storage systems (ESS). Alevo’s planned U.S. deployment will provide more than 200MW of available power to utility grids. Nuvation’s utility-grade battery management system will control the batteries in Alevo’s 2MW /1MWh ESS containers and support voltages approaching 1250 VDC. A Nuvation Grid Battery Controller™ will control parallel battery stacks and provide a central interface for grid integration and energy
Nuvation CEO Michael Worry presenting Nuvation BMS™ in a 2MW/1MWh Alevo GridBank at Parker Hannifin, Energy Grid Tie Division facilities
Nuvation BMS™ includes features such as remote monitoring and management, automated BMS firmware updating, redundant safety features, and granular battery performance optimization controls. The Grid Battery Controller™ centralizes the management of parallel battery stacks in a single device, and can be connected to external energy management controls and data analytics systems. It also includes a host of additional management features such as real-time data streaming and early identification of potential cell degradation.
Nuvation BMS™ is a chemistry-agnostic battery management system that can support lithium-ion, lead-acid, zinc-oxide, nickel, other chemistries and supercapacitors.
An Alevo GridBank Battery Stack being managed by Nuvation BMS
In 2013, Nuvation designed and built a mechatronic version of the popular mobile game Angry Birds. Keeping with our company’s Canadian heritage, we dubbed the game Angry Moose. A 3D-printed, comically large slingshot is aimed using three linear actuators which set the azimuth, angle and stretch (“anger”). These actuators are controlled by Jaguar motor controllers which take a PWM control signal generated by an FPGA. The player uses an iPad with a custom Angry Moose app to wirelessly send control data to a WiFi router, which relays the control data to the FPGA over wired Ethernet.
Arrow Electronics SoCKIT
Since then, Nuvation has been continually updating the FPGA platform with new Altera FPGA parts, adding features and tweaking the game to make it more fun. In 2014 we upgraded the FPGA from a Cyclone III, running an embedded NIOS microcontroller, to a Cyclone V running the latest NIOS II soft-core embedded processor. In October of 2015, we incorporated the Arrow Electronics SoCKIT, which upgraded the FPGA to the Cyclone V SoC and utilized the hard, dual ARM-core processor, which allowed us to do the software development in a Linux environment.
“Altera SoCs integrate an ARM-based hard processor system (HPS) consisting of processor, peripherals, and memory interfaces with the FPGA fabric using a high-bandwidth interconnect backbone.” (text copied from Altera website).
The hardware side of the project involved using the QSys system integration software to instantiate the ARM-based Hard Processor System (HPS), attach the Ethernet controller, import our existing PWM controllers and assign hardware addresses. I then used the Quartus II IDE to build the Verilog top level module and create the pin assignments. Compiling the FPGA took minutes. From there, it was a quick effort to get the development kit to boot Linux using an SD card image provided by www.RocketBoards.org. As a testament to Altera’s ever-improving tool flow, I did all of this in one afternoon with no prior SoC experience. At this point, the hardware implementation was done. The rest of the project required developing the software driver to communicate with the memory mapped PWM modules.
Not being familiar with driver design in Linux, I fumbled around, looking for similar drivers and trying, unsuccessfully, to pattern match something that would work. The online documentation at Rocket Boards consisted of a few rough tutorials and some community-generated projects with sparse documentation. I felt disappointed that documentation for SoC design was largely left up to the community and wished more had been done to provide developers with example projects. One developer was able to put together a driver that worked, but in his words, wasn’t pretty. Nevertheless, at this point our Angry Moose demo was able to receive commands over Ethernet using a simple web server and parse the commands in order to direct the PWM modules and move the actuators.
We debuted the improved Angry Moose game at Altera’s ASDF (Altera SoC Developer’s Forum), where it was a smash hit.
Helping the average person understand the energy stored by a 1MWh energy storage system can sometime involve making some pretty interesting comparisons. Where more commonly one might see something like “it will power X amount of average households for X amount of hours,” we recently came across a comparison of “the equivalent of over 2 million iPhone batteries” that sent our BMS engineering team trying to out-do each other in frivolous comparisons of dubious value.
We are pleased to share the winner here with you today, complete with cited sources for accuracy:
• 80×23,000,000=1.84 billion lemons produced each year (enough for 1 and a bit 1MWh ESS systems)
• 1,390,000,000×0.25= 347,500,000 lbs, or 173,750 tons (a 40’ ISO container maximum load is 28.88 tons, so this is 6,017 shipping containers full of lemon batteries)
It would be a huge burden on the US citrus economy as well as a huge site installation to build a 1MWh lemon-battery ESS. Not to mention this ESS is “recharged” organically by replacing the lemons from lemon trees that use the depleted lemons in their compost to grow more lemons.
But you know the saying, “When life gives you 1.39 billion lemons, you make a 1MWh ESS”
A Nuvation Engineering client in the tele-health industry was seeking assistance upgrading a health monitoring device used by patients who are managing their care at home. The device collects data from various personal health monitoring devices (PHM) and uploads it to a central monitoring station manned by live agents. The client was primarily a health monitoring services provider and developing electronic devices was not their core business.
They needed the assistance of an engineering firm that could:
Work with an RFP that was based on functional requirements and not complex technical specifications
Provide up-front visibility of the entire project effort and costs from initial design to market-ready product
Possess the diverse skill sets needed to execute both software and hardware development
Manage all the complexities of medical and electronic device product testing and regulatory certification
Manage the project until ready-to-ship products were rolling off the production line
The new device would collect health information via USB and Bluetooth from multiple PHM devices simultaneously and upload this data to the cloud. Home-based patients’ heath would be monitored at a central monitoring station by live agents who would send help in an emergency.
The current device was several years old and some components had reached parts obsolescence. The device could also only support a single PHM device and needed to support multiple devices simultaneously. Support also needed to be added for newer communication technologies since the device was currently limited to plain old telephone service (POTS) as the only mode of data transfer to the cloud. Read More
Angry Moose is Nuvation’s Canadian version of Angry Birds, but we chose the real world instead of a video game as the best place to play – with a real catapult, and real animals (okay, real stuffed toy animals). Instead of tossing birds into blocks, we catapult beavers (what else eh?) through beer cans to knock down the forest critters who stole our Moose’s beer (which made him angry…). We 3D-printed the catapult, created an iPad GUI, and run the catapult’s motor controls with an Altera Cyclone V SoC FPGA.
This Fall Nuvation brought Angry Moose to the Altera SoC FPGA Developer Forum (ASDF) in Santa Clara, CA. Check out this video of Nuvation CEO Michael Worry explaining Angry Moose while some people play the game.
For Internet of Things (IoT) sensor networks, Nuvation offers a comprehensive suite of engineering services ranging from architecture design to product development and manufacturing. When designing these solutions, there are some common design challenges that we’ve come across:
Nuvation designed an ultra-low noise, high-sensitivity acoustic monitoring sensor inside a low power and small form factor design for a Water Leak Detection System.
Low-power design / longer battery life – As IoT infrastructure becomes ubiquitous many use-cases require designing and building low power, low bandwidth, and small form factor IoT sensors and networks. Customers frequently challenge us to deliver longer battery life in ever smaller form factors, with lower volume manufacturing unit costs.
Low noise thresholds in small form factors – Many advanced sensors require a low or ultra-low noise floor. This creates an interesting challenge since traditional low noise design approaches cannot be used in a design with requirements for both low-power and a small form-factor. As the power consumption is reduced and the circuit impedance rises, the amount of noise generated thermally in the system increases.
Low cost/low power wireless communication – When dealing with multiple sensors in an industrial installation, cost per sensor is a key factor in sensor design. Wi-Fi is often rejected as it is not only expensive per sensor but also not suitable for large facilities with potential radio-interfering obstacles like multiple floors, concrete, and steel beams. Cellular is cost prohibitive due to the high fixed cellular modem costs plus high variable monthly cellular subscription costs with a cellular carrier. Bluetooth often doesn’t meet range requirements. Besides the cost considerations, the unlicensed 2.4 GHz band is a power hungry and congested band of spectrum that is sensitive to interference from other systems and emissions.
Solving these challenges has required some innovative thinking. What we’ve learned along the way has made its way into our handbook of best practices.
Here are some best practices we have learned with respect to:
Nuvation is building an autonomous beer serving kegerator robot, because we like having great conversations at parties without the constant interruption of going to get a refill. When this after-hours engineering design project is complete, you will be able to wave “Keggy” over and pour yourself a beer from your choice from two on-board half-kegs.
Note Nuvation BMS prominently displayed on the front, just underneath the Microsoft Xbox Kinect One and LCD screen. We’ll have two 5G tanks of beer on board. 6kwhr battery. 12HP of motors. The battery is over-sized for the application – 6kwhr is a quarter of a Nissan Leaf battery and will drive a car 70 miles with the A/C on.