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EEWeb PULSE INTERVIEW

EEWebIssue 75

December 4, 2012

Electrical Engineering Community eeweb.com

Distribution SystemsAutomation andOptimizationPart 2

TECHNICAL ARTICLE

MCU Wars - Episode 2.1:Developing in an RTOS

SPECIAL FEATURE

President and CEONeoPhotonics

Tim Jenks

ExpertsExchanging IdeasEvery Day.VISIT DIGIKEY.COM/TECHXCHANGE TODAY!

Digi-Key is an authorized distributor for all supplier partners. New products added daily. © 2012 Digi-Key Corporation, 701 Brooks Ave. South, Thief River Falls, MN 56701, USA

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Tim Jenks NEOPHOTONICS

Interview with Tim Jenks - President and CEO

Two experts in RTOS sit down to discuss the advantages of using a Kernel when developing in a real-time system.

RTZ - Return to Zero Comic

Featured Products

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MCU Wars 2.1: Developing in an RTOS

Distribution Systems - Part 2

26

BY NICHOLAS ABI-SAMRA WITH QUANTA TECHNOLOGYWhy Distribution Automation (DA) is considered in developing the Smart Grid as it transforms the distribution network towards more automation.

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TimJenksNeoPhotonics

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TimJenksNeoPhotonics

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NeoPhotonics is a leading provider of optical compo-nents that enable the delivery of video, voice and data over telecommunications and data networks. We spoke with Tim Jenks, the President and CEO, about their cut-ting-edge photonic-integrated circuits, what sets them apart in the industry and how they are connecting the world via optical networks.

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How did you get into engineering?

I grew up in southern California in San Diego and I’ve always been something of a mechani-cal “tinkerer.” In high school, I was pretty active in things rang-ing from music to sports, but I also spent a fair amount of time with my friends working on cars, which were some of the cool things to do in southern Califor-nia at the time. In school, I was al-ways good at math and science, so engineering was a pretty natu-ral direction for me. I went to col-lege at the U.S. Naval Academy, where I majored in Mechanical Engineering and Marine Engi-neering (which is focused on things like ship power plants). I also got into materials science at the time, which was among my favorite classes, and went on to graduate school at MIT, where I studied nuclear engineering. After that, I went into the Navy. My first work experiences were really operating nuclear propul-sion plants at sea. After the navy, I went to business school at Stan-ford and then joined Raychem Corporation, which was a mate-rials science company. It was at Raychem that I first dealt with fi-ber optic products, so when I left Raychem I joined what was then NanoGram Corporation and is now NeoPhotonics Corporation. It was a combination of having had an interest in fiber optics and materials science that put me on a path to this company.

Can you tell us more about NeoPhotonics?

The company is about 15 years

old and was founded by two people, Nobuyuki Kambe, a Japanese PhD, and Xiangxin (Sean) Bi, a Chinese PhD, both of whom went to graduate school in the U.S. They really wanted to explore novel approaches for using nanomaterials. Ultimately, the use of nanomaterials was intended to look at things from electro-chemical materials to optical materials. The early days were looking for improved glass formulations for optical chips as well as high-rate batteries that were eventually implemented in products. Back in 2002, after the telecomm boom and bust period, we divided the company into three different market ver-tical directions; NeoPhotonics continued in glass materials and optical applications while two spin outs, NanoGram Corp and NanoGram Devices, pursued other market directions. This al-lowed NeoPhotonics to focus on photonic-integrated circuits for

communications and to subse-quently pursue acquisitions to acquire new technologies and accelerate growth.

Since the early days, what has been the best product you’ve produced?

In terms of products, the core product technology—what we call photonic-integrated circuits (PICs)—are devices that pro-cess light as light. By being a light processor, the idea is that it’s an integrated circuit to which you connect an optical fiber that inserts light. Rather than having traces of metals, which would conduct electricity on a semi-

“By being a light processor,

the idea is that it’s an integrated

circuit to which you connect an

optical fiber that inserts light.”

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EEWeb PULSE INTERVIEW conductor chip, there are traces of glass or semiconductor mate-rial that are called waveguides, which conduct or route or switch light. The idea is that fibers will inject light into the chip and the waveguides and other structures do the processing. We fabricate the chips and we put them into modules that we can connect to a fiber-optic network. They work like a large-scale integra-tion platform in semiconduc-tors—you can replace 100 differ-ent discrete devices with one of these chip-based devices. You can then manufacture the chips using semiconductor tooling in large quantity mass fabrication so ultimately, much like the anal-

ogy of electrical semiconduc-tors, making optical-integrated circuits so that they are highly re-peatable and highly reliable and provide high-quality, low-cost de-signs. The products have names like “Variable Optical Attenuator Multiplexer,” or “Integrated Co-herent Receiver,” and other non-household names for a product.

Can you describe the process of making one of these photonic-integrated circuits?

If I can draw the analogy of mak-ing a device that’s like a sand-wich; think about a sandwich as an upper and lower layer of bread, and the active ingredi-

ents being between them. Our wave-guides are in the middle of an upper and lower cladding (the “bread”) and the middle of the sandwich is strips of glass that are higher index of refrac-tion; these conduct the light. In-stead of having transistors as you would have in electronic ICs, PICs can have detectors, filters, switches that direct the light or even attenuators that can reduce the “gain” of the light. You can also build lasers into semicon-ductor PICs. You can integrate a number of these devices into the chip and connect them all with the waveguides; then you con-nect the waveguides to fibers. It is a direct analogy to electronic chips, except that the devices are optical devices as opposed to transistors.

Are you a fabless company?

No. Actually we operate our own fabs in Silicon Valley. Our pro-cess uses standard semiconduc-tor industry tools, but the devices we actually make have some cus-tomization that we do in our fabs.

How small are the features of these PICs?

We use normal lithography pro-cesses. The size dimension of light requires a certain amount of “real-estate”. Therefore the devices don’t get microscopic in size; they tend to be the size of a fingernail. They can also be bigger than that, up to a square inch, but most of them are small-er. Those that are built into semi-conductor materials, in particu-lar indium-phosphide, tend to be much smaller around a few

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“We make devices that would go to the side of the home or the basement of the apartment and essentially convert electrical and optical signals,

which are the source of your high-speed internet. “

millimeters. The higher the index of refraction, the smaller the de-vice. If you imagine putting light on a chip, the light doesn’t actu-ally make 90º turns, but tends to make tight bends in a wave-guide. So there needs to be a bit of real-estate in order to make a tight bend, which is why these devices tend to be measured in millimeters to centimeters.

Are the lasers used for communication as well?

I mentioned that we have two fabs in Silicon Valley — one makes glass and one makes indi-um phosphide. There are devic-es that generate light—that con-vert electrical signals into light or that convert light signals into electricity—which are semicon-ductor lasers or semiconductor photodiodes and are made of in-dium phosphide. There are also a range of devices that can bend switch filter or otherwise aggre-gate channels or balance light signals. Those are often built in glass and referred to as silica on silicon (SiO2 on Si).

Do you sell individual components or are they all module-based?

Most all of our products are mod-ule-based. The modules are of-ten sold as components, so they would be used in telecom trans-mission equipment or plug into a server or router. Our custom-ers are all of the world’s largest manufacturers of telecommuni-cations network equipment.

Going forward, do you see your company going into other industries besides the standard telecommunications products that you are in now?

There are a number of other ar-eas that use technologies that can be viewed as adjacent, rang-

ing from data storage to medical diagnostics and therapeutics to industrial sensing applications. Essentially, what we do today goes into telecommunications, but just to give you an idea of where that goes; we make de-vices that are in fiber to the home

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“We make devices that would go to the side of the home or the basement of the apartment and essentially convert electrical and optical signals,

which are the source of your high-speed internet. “

systems (for example, this could include Verizon’s FiOS system). We make devices that would go to the side of the home or the basement of the apartment and essentially convert electrical and optical signals, which are the source of your high-speed inter-

net. The traffic that runs in fiber optic cables gets aggregated in a central office. We also sell modules that connect central of-fices of the telephone company to large data centers. Whether the data center is one that brings you Netflix video or connects Google to the network, or any of the big social media platforms, they also get connected to these types of modules. Because it’s in the tele-communications network, those networks go all over the world in every country and every city right down to very small villages in the remote countryside.

There’s a lot to do with connect-ing the world via optical net-works. Cell phones are typically thought of as a wireless device, but it’s really only wireless for about a half a mile and then it’s fiber-optic. Since everything is fi-ber optic, there are a number of adjacent markets. It used to be telephone lines, but now every-thing related to delivering digital content to you anywhere, any-time, is fiber optics.

What is the culture like at NeoPhotonics?

NeoPhotonics is a “technically-heavy” company. We have a strong R&D team in Silicon Val-ley. We also have research fa-cilities in China, in Canada and in Japan. We do heavy duty with graduate-level engineers, par-ticularly electrical engineers and physicists, but also process en-gineers and chemical engineers due to the nature of our fabs. The culture, therefore, is a pretty tech-

nical one, but it’s also one where people work together across in-ternational borders to solve prob-lems and invent devices, which is a fun aspect of the company.

For more information about NeoPhotonics, visit their

website:

www.neophotonics.com

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Episode 2.1Developingin an RTOS

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Episode 2.1Developingin an RTOS

In this episode of MCU Wars, we spoke with two experts in real-time systems: Richard Barry, founder of freeRTOS, and Jean Labrosse, President and CEO of Micrium. The discussion ranges from the advantages of using a Kernel in your product to why these companies offer their source code to their users.

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Jean

Absolutely. We like to define the difference between an RTOS and Kernel as; the Kernel is really a multi-tasking portion of a real-time operating system and a

real-time operating system contains more than just the Kernel. It’s TCPIP-

stack file-system GUI, USB-stack device, so for us, an RTOS is not just a Kernel unlike what the popular belief is in the industry. RTOS for us is really more than just a kernel.

Well, firstly I would say that even though I provide an RTOS or a Kernel, I wouldn’t say that everybody shouldn’t always use one—it’s very much a matter of the

right tools for the right application. As soon as you get into any kind of complexity

in timing, communications interfaces, something that’s maintainable over a long period of time, something that is robust and can control the execution, you come to a point where it’s easier to use a Kernel than not to use one. Communication interfaces are really the point in which the complexity gets big enough to warrant using a Kernel and it would really make your life easier.

Basically, an RTOS provides a framework for building upon applications. So instead of being boxed into certain things that you can or cannot do, it becomes very

interesting to have a Kernel, especially when you’re considering, as Richard was

saying, TCPIP file-system GUI—all these applications require a lot of CPU processing time and you wouldn’t want to have a single thread of application handle those specific modules. So an RTOS Kernel, per se, is a good foundation to build your application on.

I think one of the key points, for me, is maintainability. You can write any application without an RTOS, but as soon as you add in extra functionality or

change the hardware platform you are

running on or change the optimization, you don’t want your application to behave differently. Maintainability, to me, is everything in software development and that’s a Kernel really helps with that.

What’s the difference between RTOS and Kernels?

Why would a user want a Kernel in their product?

Richard

Jean

Richard

We don’t use the word “open-source” because in the industry, open-source is viewed as free software to use in your application. In our case, our software

is authored in source-form for free evaluation. But we expect customers

to license our product once they decide to use it in a commercial setting. We provide software in source-form because it makes it a lot easier for customers to actually tailor the software, if they need to, for their application. It’s a lot easier to work with different compilers, it’s a lot easier to work in different environments, different

Both of you offer your source code to your users. Could you give us a few reasons why that’s

valuable to the user?

Jean

From the left: Cody Miller of EEWeb, Richard Barry of freeRTOS and Jean Labrosse of Micrium

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processors, so having the software in source-form is a huge advantage to customers. They see the quality of the software as not like you’re hiding behind the object code that’s very important—we put a tremendous amount of pride in creating the best looking software you can put your eyeballs on.

I agree with Jean that having the source-code is very important. There are people that say, “if you want to support a product, you can only give it to people

in binary form, because as soon as they start changing it, then it becomes

unsupportable,” which is absolutely right. If people do start changing it, then we can’t support them, so they can change it if they want, but then there are limits to what Jean or I can do to help you from that point. Counter to that, I think that when you have the source code, you can see how much is working and it’s much easier to de-bug. You can also step through the code—if you think there’s something wrong, you can see exactly what the code is doing, whether it’s doing what you expect it to do or not.

My personal product is in what I call “moderated open-

Richard

“Communication interfaces are really the point in which the complexity gets big enough to warrant using a Kernel and it would really make your life easier.”

source.” It’s not open-source in the traditional sense—it is a free part that you can download in source form and once you’ve downloaded it, it is effectively open-source to you, so you can modify, distribute it and even sell it. The reason it differs from traditional open-source is that the way we have developed the whole product is to try and remove all of the objections that people have to using open-source. One of the major objections is that there’s ambiguity in IP ownership. You don’t want to build something into a product that sells millions of units and then find that you have a problem because you’ve accidentally put someone else’s IP in it. So when people contribute back to free RTOS, all that code is made completely available for free to everybody, but is kept separate from the core product, so that we know where everything came from.

Continued in Part 2...

To view this episode of MCU Wars and other EEWeb videos:

Click Here

From the left: Cody Miller of EEWeb, Richard Barry of freeRTOS and Jean Labrosse of Micrium

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Nicholas Abi-SamraVice President of Quanta Technologies

DistributionSystems

Part 2

Automation &Optimization

Vice President, Asset Management - Quanta Technology

Present day Distribution Automation (DA) goes beyond reducing manual procedures. DA makes distribution systems more controllable and flexible based on accurate data for decision-making applications. This is accomplished through a set of intelligent sensors, processors and fast communications to remotely monitor and coordinate distribution assets.

DA is considered a foundation to build upon in developing the Smart Grid as it transforms the distribution network towards more automation.

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Nicholas Abi-SamraVice President of Quanta Technologies

DistributionSystems

Part 2

Automation &Optimization

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V. FAULT DETECTION, ISOLATION AND SERVICE RESTORATION (FDIR) OR FAULT LOCATION, ISOLATION, AND SERVICE RESTORATION (FLISR)

FDIR and FLSIR are interchangeably used terms which refer to the same feeder fault management approach. Basically, this approach is divided into:

1. The fault detection and isolation step

2. The decision support and procedures necessary to reconfigure system and restore (R) power to customers.

They are made of the following elements:

• Detection that an outage has occurred

• Determination of the location of the fault

• Isolation of the faulted section

• Re-energization the un-faulted sections of the feeder

FLISR is able to restore service in one minute or less following the initial fault, resulting in significant reliability improvement compared with the traditional manual restoration process.

Fault Detection Methods – Then and Now

Then… Local fault passage indicators tripped by the passage of a high current above a certain threshold have traditionally determined fault locations. Field crews had to travel to each fault indicator site to see if it was set or not.

Now…Telemetered fault indications by a SCADA/DMS system and used by the in conjunction network topology model – to determine the section of the feeder in which the fault has occurred based on measured phase voltage and current waveforms. When a feeder has a tree-like structure with multiple branches, several theoretically possible fault locations – all having the same network impedance – may exist.

Challenges for Accurate Fault Locating

A source of error when estimating the fault location from fault impedance measurements is that the fault impedance itself is not known. If the fault has significant impedance, the estimated fault location (assuming zero fault impedance), may be further away from the substation than the true location.

Nonetheless, this information is still very useful since the estimated fault location distance from the substation is an upper boundary, and dispatchers can know that

the true fault location is closer to the substation. Since the fault impedance tends to be purely resistive, another alternative is to do the calculations considering only the reactive component of the impedance values.

FLSIR Centralized or Decentralized

FLISR applications can utilize decentralized, substation, or control center intelligence. Each FLISR approach has benefits and drawbacks.

Some utilities could determine whether a limited deployment of intelligent switches in a decentralized or substation organization will be sufficient to improve the worst-performing feeders (WPF) without a full rollout. Other utilities may approach FLISR on service-area wide through distribution management system (DMS) implementations.

One approach could be to provide C&I customers with local switches organized into a peer-to-peer, ultra-fast decentralized system utilizing deterministic communications, while consumers, with less demanding needs, could have FLISR run through the control center DMS or the substation.

Decentralized(peer-to-peer)

Substation

ControlCenter

Requires leastbandwidthScalableFastest restorationof feederLower introductioncosts

ScalableProcessedinformationrequires lowerbandwidthbackhaulcommunicationthan peer-to-peer

Full system viewfor restoration

Lacks overallsystem viewStill report statuson backhaulcommunicationssystems

Reliableprocessing insubstationLacks overallsystem view, butmore than peer-to-peerSlower restorationtime than peer-to-peer

Slowest restorationtimesRequires the mostbandwidthRequires a DMS

Approach Benefits Drawbacks

VI. AUTOMATION FOR LARGE SUBSTATIONS

Substation automation (SA) is not new. Substations have been equipped to perform automatic reclosing, automatic bus sectionalizing, automatic load transfers,

Table 4: Different Deployment Techniques for FLISR

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automatic capacitor switching, etc. for many years using a combination of control panels, auxiliary relays, switches, transducers and exclusively with copper wiring. Today SA encompasses the deployment of operating functions and applications to enhance operation and maintenance (O&M) efficiencies and optimize the management of capital assets in substations. It involves integrating protection, control and data acquisition functions and includes deployment of supervisory control and data acquisition (SCADA), equipment condition monitoring, volt/var control and alarm processing, etc. Some of the other functions of SA: Today SA includes functions such as:

• Automated retrieval of data

• Automatic generation of switching sequences

• Detection of fault location

• Diagnostics of system disturbances

• Equipment diagnostics through sensors

• Load shedding

• Local & global alarm & warnings

• Physical Security enforcement

• Protective Device Coordination

• Supervision of interlocks

At least from a logical point of view, SA systems comprise three levels, as shown in Figure 3. There is not only vertical communication between the levels (e.g., between bay and station level), but also horizontal communication within the level (e.g., in the bay level between bay units for functions like interlocking).

For new substations, the Substation Automation systems are specified as part the overall specification taking into account all the relevant interfaces. For retrofit, the SA system is specified stand-alone but referring to the dedicated requirements of the existing substation as boundary. All functions needed are specified either from the functional point of view only or by referring to some predefined devices meaning control, protection and monitoring units.

Today, SA uses Intelligent Electronic Devices (IED) as the primary source of data from the substation and local Area Network (LAN) to transmit data and control commands, and can perform many functions in addition to the legacy ones. Communications with substations have taken forms including leased or dedicated telephone lines, cellular, satellite transmissions, fiber-optic networks and radio.

Figure 3: Substation Automation Levels

Wide AreaNetwork

Station Level

Bay Level

Bay #1 Bay #n

Process Level

Equipment #1 Equipment #n

Protection

Station Host Station HMI Data Gateway

Control Protection Control

Sensors Actuators Sensors Actuators

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VII. DATA INTEGRATION FOR SA

Substation data integration poses a number of challenges, a large number of which are solved by IEC 61850. Integration of substation IED data often called “data warehouse” or “data mart”. Recorded event data collected from various substation IEDs. This includes acquiring, or collecting, data which may in the form of measured analog current or voltage values or the open or closed status of contact points. Acquired data can be used locally within the device collecting it, sent to another device in a substation, or sent from the substation to be used by different users, including system operators. This data needs to be “translated”, audited, and prioritized before it is sent along. Similarly, control data or command messages need to authorized and authenticated. This is depicted in Figure 4.

Application of Substation Automation for Condition Monitoring

Substation automation includes several topics, such as:

• Data acquisition (sensing and monitoring techniques, and “intelligent” capture)

• Communication architecture (network and protocol)

• Data processing and storage

• Diagnostics

• Maintenance

• System integration

VIII. ELEMENTS OF SUBSTATION EQUIPMENT CONDITION MONITORING – AN EXAMPLE OF SA

An open-system approach, based on IEC 61850, can be an effective and efficient solution for equipment new and existing substations. Some of the major advantages of such a solution includes the following components.

Sensors

Sensors for substation condition motoring can be simple or complex, depending on the parameters to be monitored and monitoring techniques as shown in the Table 5 for transformer condition monitoring. Sensors are also used on other such as: surge arresters, circuit breakers, instrument transformers, capacitor banks, station batteries, etc.

Figure 4: Substation Automation ExampleSubstation Security Perimeter

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Data Handling, Signal Processing and Local Expert System– Sample Requirements

• Data acquisition modules with sensor interface modules to provide a common communications means to other system modules.

• A database module to provide:

o Data for on-line processing

o Data for archiving (for later analysis and retrieval)

• On-line expert systems: May include pattern-recognition, or neural-network processing for complex analysis and data reduction. Decisions made based on:

o Design of component

o Operating conditions

o History of that component’s performance,

o The results of any off-line testing/off-line inspections

• The local expert system must provide answers to four fundamental questions, at the time anomalous conditions are detected:

o “What’s wrong?”

o “What action should be taken?”

o “How long before action must be taken?”, and

o “What will happen if no action is taken?”

Based on the above, SA could reconfigure the system rapidly to maintain availability of the power throughput of the substation.

Concluded in Part 3...

About the Author

Nicholas Abi-Samra has been actively involved in IEEE for more than 35 years. As Vice President of Asset Management at Quanta Technology, he and his team help utilities better manage and modernize their assets at lower total lifecycle cost. He was both General Chair and overall Technical Program Coordinator for the 2012 IEEE Power & Energy Society General Meeting.

Top Oil and WindingTemperaturesOperation conditionassessment

Water contents in theoil (moisture)Oil dielectric strength

Partial DischargeOil/Paper insulation

Hydrogen sensorMulti-gas-in-oil sensor(besides hydrogen)

Top OilRTDsExternally mounted sensorsWinding Hot-SpotOlder techniques:Thermistors, RTDsNewer (Fiber-Optic)Extrinsic Fiber carriessignal to external sensorand Intrinsic Fiber itself isthe sensorAnalogy and electronicsimulating

Thin-film capacitive elementtechnology to calculatewater ppm

Electrical methodsAcoustic methodsUHF methods

Oil PumpBearing wearassessment

Load Tap Changers(LTC)LTC and contactcondition assessment

assessment

Sensors to sense changesin gap between shaft andbearing surface

LTC tank temperatureGas-in-oil in LTCTap positionLTC motor currentand torquesElapsed time of tap changingVibrationAcoustic signatureStart/Stop cycle

Capacitance and PFmeasurementSum current

Sub Monitored/Purpose

Example of MonitoringTechniques

Gas in OilOverheat, arcing,partial discharge,insulation aging

Table 5: Sample Measurements/Sensors for Power Transformers

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