Power Quality Chain of Command

Nov. 2, 2013

As the Smart Grid and distributed energy marketplace continues to evolve, the need for innovative products that maintain power quality is growing. Poor power quality leads to inefficiencies in power usage and can damage costly electrical components, from transmission equipment right down to sensitive systems used in data centers, hospitals, pharmaceuticals, and many other industries with mission-critical needs. Backup power control systems, UPS, and generator control switchgear are the first line of defense for mission-critical systems, but there’s much to consider regarding the choice of systems and support to maintain them.

Looking at the big picture, a good backup system needs components that are designed to work together, according to Harry Handlin, director of Critical Power Applications for GE, Fairfield, CT. “You need to look at the whole distribution as a critical power system, rather than just isolate the UPS or the standby generation, or the paralleling switchgear,” says Handlin. “Everything has to work together seamlessly, and that includes the relays on the medium-voltage switchgear, the relays at the substation onsite, all the way forward to make sure you have a consistent and reliable power distribution system.”

Handlin’s philosophy reflects GE’s full line of backup products for data centers and other mission-critical environments, and GE can supply the entire power distribution system, from the utility substation to an IT server. In June 2013, GE introduced its new TLE Series uninterruptible power supply (UPS) global platform. The TLE Series transformer-less, three-phase UPS applies GE’s technology to provide facilities with best-in-class operating efficiencies-up to 97% efficiency in double-conversion mode and up to 99% in eBoost, also known as multi-mode, operation. The system has a broad range of double-conversion output power, ranging up to 1.5 MW in a single module. To meet customers’ reliability, efficiency and power demands worldwide, the TLE Series is offered in both UL and CE versions.

Handlin notes for efficiency, the cost of such systems has a significant effect on the customer’s bottom line, in two ways. “You have a capital expense with the equipment cost,” says Handlin, “and when you operate a UPS you take the AC [alternating current] power coming in and convert it to DC [direct current], and then convert it a second time back to AC, so it puts out a high-quality regulated power source. It’s referred to as double conversion system, and anytime you do that you have an efficiency loss. So, you are using up energy in double conversion mode, and it adds to your operating expense. Typically, most UPS double-conversion units on the market operate at about 88% to 90% efficiency. This new model that we are introducing is actually 96 1/2 % efficient in double conversion mode. And, we also have a mode of operation called eBoost, which is often referred to as eco-mode or multimode. It allows us to see when the utility power is good enough to power the load without converting it, and if there are any anomalies on the utility line it can transfer back to the double conversion mode in 2 ms, which is fast enough to support the IT loads, servers, and network equipment. In that mode, we actually get up to 99% efficiency.”

In December 2012, GE announced the launch of its Zenith Controls ZT30 UL 1008 listed 30-cycle automatic transfer switch (ATS). Designed to help maximize system availability in critical facilities, such as hospitals or data centers. The ZT30 helps to isolate a fault condition to restrict outages to the equipment affected and maintain power to critical equipment. The ZT3O also has a Quick Make/Quick Break design that enables manual operation with the door closed, minimizing the operator’s exposure to arc flash. A patented shutter door is available so when the ATS portion of a bypass switch is tested or maintained, the door covers the live bus bars, to protect maintenance personnel.

The demands placed upon testing backup and UPS systems at data centers are expanding. For example, water cooled server racks have added another layer of complexity, according to Mike Hobbick, chief applications specialist/president, ComRent West, Inc., Pomona, CA. ComRent supplies load banks, a product used to test power systems by applying a load that can simulate the load seen by a power supply system, such as gensets or backup systems. “We just introduced water-cooled load banks, so this will replicate the heat load of a water-cooled server rack,” says Hobbick. “It makes a critical difference in the test results. You can do fluid modeling and load modeling in software, but you get the answers and understand how it works when you actually put real heat and electrical load through a system.”

Hobbick notes that other industries are adopting smaller data centers within their locations. “We’re seeing hospitals digitizing medical records and other data, so they’re starting to build out data centers on their premises. Of course that means a UPS and a wide variety of UPS and battery combinations. But any power storage power generation device should be tested after it’s installed as a complete entire system. So, you’re testing all the subsystems such as fuel delivery, fire suppression, and other issues that must all work together for the system to operate properly.”

Another area for testing pertains to the discovery of power factor issues. “We have a customer that has data centers nationally and internationally, and they discovered that the problem they had with the UPS equipment in their facilities was because a power meter on the UPS only indicated with the power factor was, but didn’t indicate whether it was leading or lagging,” he says. “So, they may have the same issue at multiple locations and needed to undergo a power quality study to determine if there’s a potential issue.”

According to Jim Clark vice president of engineering, Staco Power Systems, Dayton, OH, power factor problems are common in many industrial and commercial environments. “It’s typically generated from within the factory, and it depends on the kind of equipment that’s running,” says Clark. “You could have an appliance in your factory that’s generating high harmonics, for example, and if there is a point of common coupling where the utility meets the building, you as the owner have a responsibility for the harmonics that you injected back into the utility feed.”

The consequences of harmonics in equipment with capacitors could be an explosion. “In some instances, because of problems with the power from the utility, high harmonics can be generated with high voltages that will affect the capacitors in our own equipment, so we have to install harmonic mitigating equipment to protect our capacitors,” he says. “So, it’s a situation that we have to deal with when we install specific equipment to correct one problem yet keep ourselves from being affected by a different problem in that building.”

Staco’s harmonic filters perform mitigation for a wide array of needs. This includes equipment to help reduce amplification of harmonics when capacitors are automatically switched, to suppress one or more specific harmonic orders, and to lessen a broad range of multiple harmonic orders.

Switchgear equipment plays an important role in backup systems, but it’s more than just controlling backup generators. The equipment can also be found in utility substations, or a substation for a large user of electricity, such as a university campus. Switchgear equipment is also found at nuclear power plants, and they can be stressed beyond their operating parameters, as in the case of Duke Energy’s Harris nuclear power plant, where a switchgear explosion last August 2013 resulted in a shutdown of non-safety related power distribution equipment. But no matter the location, proper control and monitoring is important.

Eaton’s Electrical Sector, Eaton, Cleveland, OH, recently launched their new IEC switchgear called Xiria E, an extendable single panel version of the Xiria switchgear line, designed for medium-voltage distribution networks. The Xiria E is specially developed for distribution substations for utilities and bigger commercial and industrial applications. The system is designed to be highly flexible and contains a broad range of protection and control options, plus, the capability for future extension of secondary switchgear systems. Xiria switchgear uses Eaton’s field proven vacuum interrupters, which require no maintenance and are certified for 30,000 operation cycles. The complete system approach is again the goal. Xiria E is an extension of Eaton’s product family, including MMS (double busbar switchgear), Power Xpert UX (withdrawable switchgear), W-VAC (vacuum circuit breakers) and Power Xpert FMX (demountable plug in switchgear). In combination with Eaton’s low-voltage switchgear, busbar systems, UPS products, project management and service capabilities, the Xiria E can be part of a complete solution.

Smart Grid connectivity is another factor for companies offering complete solutions. At BPL Global, Ltd. (BPLG), a smart grid technology company based in Pittsburgh, PA, the latest next-generation products include Connected Energy Substation Automation, a solution designed to enable substations as an intelligent hub within the broader smart grid. Improved grid reliability and asset management is the goal, as well as reduced maintenance costs through the integration of data from discrete substation systems and visualization for management and control of substation assets. BPLG’s Substation Automation consolidates data from these intelligent electronic devices (IEDs) and provides grid operators with a real-time view of substation status and operation, as well as facilitating better management and control over substation assets.

Substation Automation is part of the Connected Energy suite of smart grid solutions including Transformer Monitoring, Demand Management, Grid Management and Distributed Energy Resources (DER) Management. BPLG solutions collaborate across the grid on a common platform providing a higher return on investment in advanced distribution automation.

Worldwide, switchgear and other components within a substation are seeing major technology advances and a steady uptick in market growth. According to Pike Research, in the past, the market for substation automation equipment, including communications, protective relays, supervisory control and data acquisition (SCADA) devices, and related sensors, moved as a mature technology, as in slow and steady. But, today, substation automation within the broader smart grid architecture is gradually shifting the nature of the substation automation opportunity. Now it’s newly automated smaller distribution substations, and retrofit modernizations of previously automated transmission substations are gaining favor. This trend will drive steady growth in the global market for substation automation, with growth from $2.7 billion in 2012 to $4.3 billion in 2020.

At Alstom Grid, Washington, DC, product designers are linking the automation of electrical substations with the automatic acquisition and processing of data coming from the IEDs installed inside the substation. This information will help to manage the protection devices and allow faster, more efficient decisions due to better awareness of conditions at the substation. The company’s P60 Agile, is the latest offering of IEDs providing a comprehensive one-box solution. It features protection, control, recording and measurement of electrical power systems, and targets smart distribution networks for utility operators and industry. The P60 Agile’s human machine interface (HMI) featuring a large, fully programmable and ergonomic color touchscreen.

Advancements in control panels haven’t stopped at utility scale operations. For example, Dranetz, based in Edison, NJ, a provider of intelligent monitoring solutions for electrical demand and energy and power quality, has energy panel meters that offer a wide range of power data for building managers. The company’s Encore Series Energy Panel Meter helps in reducing consumption during peak times or shifting loads to off-peak times. Energy and demand data can be gathered for an entire facility and at key consumption points, including energy-intensive processes and key machinery. Encore Series Software automatically plots and trends this data to develop daily, weekly, monthly or yearly load profiles. The software can also alert users to shed loads before a new demand level is reached. The Energy Usage Answer Module and Encore Series Software can aggregate energy from multiple points, and compute costing information and provide other advanced energy reports.

With automation in substations growing, it’s important to note that substations rely on batteries, and proper maintenance is critical to a battery’s ability to operate and protect components in substations, plus, generating stations, transmission stations, or certain distribution substations that utilize any type of equipment that interrupts the flow of electricity. Also, these could include circuit breakers, reclosers, and switches.

“All of the equipment in a protection system has to be maintained and the maintenance must be documented,” says Rick Tressler, senior training engineer, Alber, a manufacturer of storage battery monitoring and test equipment, based in Pompano Beach, FL. Alber offers a line of real-time battery monitoring and electrolyte level sensing systems designed specifically to comply with the North American Electric Reliability Corporation (NERC) PRC-005 standard.

“Utilities must follow the standards and keep records for NERC, and every few years the utility will get a letter from NERC saying there will be an audit, so they must submit documentation. Sometimes there’s a combination of both a record and onsite audit,” explains Tressler. “The bottom line is that your program must be documented, and maintenance deficiencies must be corrected. It’s a big deal, and if NERC finds that the obligations weren’t fulfilled or documented, then, as far as they are concerned, it never happened, and that’s a violation. Violations can cause fines as high as $1 million a day. So, it’s much less expensive to do a maintenance program properly, rather than incur these fines.”

Alber’s BCT-2000 capacity test system can be used to test any size battery string up to 256 cells, and performs constant current capacity and power capacity tests. It supports UPS testing using AC load banks, and supports run-down testing using system load.

“People don’t do capacity testing very often and a lot of it has to do with the fact they are uneducated about the benefits,” says Tressler. “The software is setup to run the tests, and the battery is discharged in a very controlled way. It tests the battery against what the battery manufacturer says the battery is capable of doing under a given set of conditions, then compare the results with the rate of published capacity for the battery.”

As new battery systems enter the market, such as lithium-based technologies, new load bank systems are addressing their needs, according to Brian Cleary, general Manager, HPS Load banks, San Diego, CA. “There are so many different types of battery systems and UPS, and inverters, and a lot of those are actually DC units, and they require a different kind of load bank from the typical ones used for a standby generator set,” says Cleary.

With the evolving technology, a heightened awareness has followed, and Cleary notes that data center managers are concerned about backup systems, especially in light of the fact that double-digit megawatt power requirements are now common in the industry.

“We’ve seen how data centers have grown in size, and 50 megawatts of backup is not uncommon anymore,” he says. “And, it’s coupled with the large systems and fuel that deteriorates over time, so it’s critical to keep the diesel fuel as fresh as possible. But, wet stacking happens when fuel ages or a generator builds up too much carbon because it wasn’t being used to its full capacity. So, load banking works to make sure that the system reacts when it’s called upon, but we’re also doing it to keep the system and the fuel fresh. It also helps identify older engines that don’t run at full speed. When that happens, it creates a flicker or bobble in the electrical system, so managers are finding these things and asking how do we keep the engine running as reliably as we can under a wide band of circumstances? Load banking can help fine-tune these products to make sure they perform to specified conditions.”

It’s common to rent load banks and according to Mark Prevoznik, sales and marketing manager at Avtron Load Bank, Inc., Cleveland, OH, portable rental load banks have grown to meet a variety of demands. “We supply portable load banks to the generator service guys, and they can use them to test a set for four hours to make sure things are okay,” says Prevoznik. “They have to be rugged, because if you’re a customer and you’re paying for a test of four hours, you want to make sure that the load bank works consistently. If it fails at three hours and 59 minutes, he’ll be redoing the test.”

Starting at a weight of just 69 lbs, the Avtron Liberty Load Bank (LPH series) is available in three standard versions, including 55 kW at 240 or 480 VAC, 3-phase, 60 Hz,25 kW at 120/240 VAC, 1-phase, 60 Hz, and 75 kW at 240 VAC, 1-phase, 60 Hz. It is light enough to be easily moved and transported by one technician. The Avtron Minuteman Load Bank (LPC series) provides up to 100-kW resistive load at 480 VAC or 240 VAC, 3-phase, 60 Hz. The Avtron Freedom Load Bank (LPH series) is rated 100 kW at 480 VAC, 3-Phase, 60 Hz and 93.75 kW at 240 VAC, 3-Phase, 60 Hz. Designed for continuous operation, this Avtron Load Bank gives users the Freedom of a high-capacity load in a lightweight and ultra-compact package. Avtron offers a line of load bank trailer packages for high power over the road, mobile testing at multiple sites. Resistive, Reactive, or DC models are available.

For reliability Avtron resistive load banks feature Helidyne resistive elements. These Avtron designed and manufactured elements are made of a corrosion resistant chromium alloy and are fully supported across their entire length on stainless steel support rods with segmented ceramic insulators. Elements are selected to operate at low temperatures to provide extended, reliable performance, eliminating the need for a “cool down” period after load bank operation.

The need for testing and monitoring systems for utilities is creating a substantial marketplace for full service offerings. For example, EnerNex Smart Grid Labs, Knoxville, TN; and MET Labs, Baltimore, MD, recently announced an arrangement for collaboration on testing, analysis, and training services for their energy industry clients. The companies offer solutions to utilities and their vendors that include, distribution automation system testing, cyber and physical security testing, utility communications protocol testing, advanced metering infrastructure testing, meter accuracy, reliability and safety testing, and photovoltaic panel testing.

The rise of cloud-based, software as a service (SaaS) products is another area of opportunity for companies serving utilities. New cloud-based platform to help utilities grow and manage distributed generation resources. West Monroe Partners, Chicago, IL, a business and technology consulting firm, recently launched ConnecttheGrid, a software platform to help utilities and municipalities manage the growing number of distributed generation (DG) technologies within their jurisdictions. The cloud-based platform helps utilities address major areas that are required to effectively integrate and manage the increased number of distributed (including renewable generation like solar and wind) generation resources over the next decade. According to Tom Hulsebosch, managing director of West Monroe Partners’ Energy & Utilities practice, “The recent growth of distributed generation resources brings a new set of challenges for electric distribution utilities and new opportunities for the end-users”

As microgrids continue to gain acceptance, software solutions for the design, optimization, and online operation of these systems in mission-critical electrical power infrastructure has much potential. To capitalize on the opportunity, ETAP, Irvine, CA, recently announced its own corporate campus microgrid. According to Farrokh Shokooh, founder, president and CEO of ETAP, the company is making a conscious decision, and a sizable investment of resources, to broaden its knowledge of best practices in the alternative energy arena. The completed microgrid is expected to generate 180 kW of electricity, and will save an estimated $40,000 to $50,000 per year in annual energy costs, while providing 12 car-charging stations for electric vehicles. The microgrid will be controlled by the company’s ETAP Real-Time software platform, which enables online monitoring, simulation, and demand-side management of Smart Grids and microgrids.

Microgrids can employ photovoltaic (PV) systems and wind turbine generators, and because these technologies are exposed to the environment, they need special protection, according to Carsten Wagener, head of business development for industrial applications, Raycap, Post Falls, ID. “Lightning is the most damaging event,” says Wagener, “but when you talk about surge protection, more often in electrical systems we have switching actions which happen thousands of times a day. This can cause transient events over the lines in AC or DC, and that could damage a system.”

Distributed Energy With Reciprocating Engines Offer Power Quality Assurance
Problems with power quality often reflect on the stability and reliability of a utility feed, but the growth of distributed energy reflects the benefits of sidestepping the grid and generating power onsite. And, today, it’s easier than ever to follow in the footsteps of thousands of businesses that have the ultimate in control over their power quality. There are many solutions and methods available, but let’s take a look at one of the longest running solutions on the books: reciprocating engines with generators (gensets).

For standby and backup, diesel is typically the fuel of choice because it allows for fast response times from the genset. But emissions regulations limit runtimes to emergency use and maintenance testing. Emission control systems can allow diesel engines to meet most federal, state, and local regulations, but it becomes cost prohibitive for most applications. On the other hand, natural gas is relatively free from such issues.

“There’s a surplus of natural gas out there and, compared to the cost of running diesel, is a great difference, and your life expectancy with a natural gas unit is a lot longer than running it on diesel just because of the how clean the fuel is,” says Don Zost, sales manager, Depco Power Systems, Houston, TX. “A lot of people are going that route. And, when I was in Venezuela, I saw that many companies had already converted, and it’s the wave of the future.”

Depco sells both new and used gensets, and Zost notes that buying used equipment can save thousands of dollars on high-quality products that have been thoroughly refurbished. Moreover, delivery times can be much faster than the typical waiting periods for new equipment.

The majority of our business is in the used market, and it’s a whole ecosystem in itself,” says Zost. “It’s not like buying a machine at an auction. These are inspected and serviced and guaranteed by Depco. And, we can typically get a unit out in one to two weeks, depending on what bells and whistles the customer wants.” The bells and whistles include features such as, breakers, voltage controls, sound attenuation, and cooling systems.

“We’re very flexible,” explains Zost. “We took a pair of Cat G3516 natural gas 750-kilowatt units that were originally used offshore so they were cooled by water, and we removed all the cooling apparatus and added new roll off skids, radiators, and converted them from 480 to 600 volts. We added a catalytic converter to meet emissions regulations; a new panel and breaker switches; and also a new electrical system, auto safety shutdowns, and an air starter. Of course, it was a rush job.”

Offering machine shop services leads to an interesting variety of projects. “In our shop right now, we have a two-megawatt Cummins diesel genset that’s going to a data center,” says Zost. “Also, a 200-kilowatt natural gas unit going to a drilling contractor, a two-megawatt mobile unit that’s going to a rental company in Canada for a drilling operation, and a couple of 250-kilowatt mobile units that are going through the shop right now. We warranty the units, and one of the first questions we ask is what kind of emissions regulations do we have to meet.”

According to Bruce Prange, president and chief operating officer, Blue Star Power Systems, Lake Crystal, MN, emissions regulations have a significant impact in determining the right genset “Emission standards vary by location,” says Prange, but the Environmental Protection Agency mandates that engines used in certain applications meet certain criteria-for example, a unit that’s 750 horsepower or less, and placed as an emergency standby unit that’s only scheduled to run during a weekly test or when there’s an actual power outage can still be EPA Tier Level 3, and that means diesel engines in this category. Natural gas doesn’t have EPA Tier Levels because they’re EPA-certified, and that’s regardless of use. But beyond EPA, regulations vary by locations.”

Many of Blue Star’s gensets are used for utility peak shaving and time of use programs, where electric utilities offer incentives reducing the amount of electricity drawn from the grid during prescribed hours. “A 750-horsepower engine is typical for a 500-kilowatt application, says Prange. “There are a lot of facilities out there, and smaller operations that are working with the electrical utilities in these programs.”

In many situations, customers need custom modifications, to meet needs such as sound attenuation requirements, physical size limitations, and voltage switching. “It’s not too often that we don’t have a unit on the floor with a voltage change switch requirement,” notes Prange. “It’s complex, depending on the size of the unit, and the bigger it gets, the more complex. We had an 800-kilowatt machine that needed voltage changing capabilities, and you just can’t get a switch that will handle that amperage, so we designed a custom solution, because it’s physically impossible to build a switch that you can turn the handle and change the voltage with that kind of current.”

Blue Star offers remote maintenance services that can save time in addressing operations problems. “We can track our units; one service plan uses a cell phone-operated device to monitor a genset’s controller,” explains Prange. “If a parameter goes out of specifications, it will send a text message to a cell phone, or we can monitor it remotely with a computer and start and stop the unit from anywhere in the world. Another online method allows us to take control of a unit, and anything that you can see standing in front of the unit is accessible from anywhere in the world. So, we can see information such as the kilowatt output, the load on the genset, and how much fuel is in the tank.”

Raycap products include Strikesorb, ACData, and Rayvoss industrial surge protection solutions, to protect and prevent successive electrical surges from causing damage to the AC-powered equipment. Industries served include telecommunications, energy, defense and others. Raycap’s industrial AC surge protection devices and wind turbine surge protection products (trans voltaic surge suppressors-tvss) eliminate the risk of lightning and power surge damage to mission-critical equipment.

Surge protection at a smaller scale has seen the development of a new spin on an old technology. Littelfuse, Chicago, IL, recently released its SB6100 Industrial Shock-Block GFCI and EGFPD, the first ground fault circuit interrupter (GFCI) device to meet UL 943C Class C and Class D requirements. Until now, GFCI devices have not been practical in industrial settings. GFCI devices operate by sensing a ground fault and opening the circuit quickly. However, the GFCI devices used in residential and commercial applications are too sensitive to operate in industrial applications without nuisance tripping. Target applications of industrial GFCI devices include electrical cabinets supplying power to pumps, paint booths, washers, mixers, welding equipment, and any high voltage machinery subject to wet conditions or washdown cleaning. In addition, industrial GFCI devices can be mounted in movable enclosures for flexible use.

All told, from microgrids to the Smart Grid, and from utility scale power quality down to GFCI protection in smaller industrial settings, the power quality and protection marketplace continues to evolve, and innovative products and services are providing new levels of performance and efficiency. 
About the Author

Ed Ritchie

Ed Ritchie specializes in energy, transportation, and communication technologies.