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201612 White Paper - Rethinking the traditional UPS

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As a follow up to our webinar “No-Break Vs Conventional UPS”, Brian Garner, CE+T Power Sales Manager South USA, wrote an interesting and informative white paper on “Rethinking the traditional UPS”.
In this white paper, Brian analyzes how outages occur, reviews traditional solutions and discusses their shortcomings. He explains why CE+T Power designed the 48V DC modular No-break technology and highlights the innovative answer it offers.

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201612 White Paper - Rethinking the traditional UPS

  1. 1. Whitepaper Rethinking the traditional UPS Despite the name, Uninterrupible Power Supplies (UPSs) are interruptible and they do fail. In fact, most UPS designs have multiple points of failure. This paper discusses those points of failure and an alternative design philosophy. October 2016, written by Brian Garner Sales Manager South USA CE+T Power
  2. 2. www.cet-power.com 2 Rethinking the Traditional UPS This white paper provides an assessment of powering the Mission Critical environment. Due to the various shortcomings of “Grid” power, alternatives for providing AC power must be considered. While we examine several ways to increase availability of the network, we concentrate on the current method of deploying an Uninterruptible Power Supply. We must also consider how to mitigate this risk. The downside with the UPS is the multiple points of failure. We will evaluate the negative aspects and suggest improvements. The CE+T Power solution solves the inherent problems and shortcomings of providing AC power in the Mission Critical Environment. We do this by combining the best attributes of our world class modular inverter and those of partner rectifier systems to create a system capable of providing AC power backup, without the multiple points of failure. Outages: how do they occur? According to the Allianz Group1 , “Power cuts are becoming more and more frequent. Large-scale, supraregional blackouts are increasingly a realistic scenario. Even small outages can have disastrous effects on unprepared businesses.” Additionally, “Many companies are unprepared for business disruptions caused by power blackouts, and are often unaware of the true costs and impact that they can have on their operations.” The causes of unplanned outages are varied. The Uptime Institute published a web article which states that only 12% of outages were weather related. The remaining 88% of outages are human or mechanical related. Broken down further, the root causes are UPS System failures (battery) at 29%, human error/accidental at 24%, environmental control equipment failures at 15%, generator failure at 10% and IT equipment failure & other as the remaining reasons for failure.2 The focus in a mission critical environment should be to determine the best method of providing AC power and ensuring it is always available. The loss of power can have far reaching effects. It is not only data centers and hospitals that rely on critical power, there are many other types of businesses that benefit, they include, but are not limited to: Manufacturers Banks Telecommunications Companies Cable TV Companies Municipalities Water Treatment Facilities Universities Utilities Railroads Oil & Gas Currently, the availability of the Power Grid in the US is in the range of 99.9% or three 9’s. This calculates to 1 Hodge, N. (2012, April 10). Power trip. Retrieved July 10, 2016, from http://www.agcs.allianz.com/ The article quotes, Michael Burch, Head of R&D Risk Consulting and Larry Hunter, Risk Engineer, both with Allianz. 2 Weckworth, J. (2015). Data Center Outages, Incidents, and Industry Transparency. Retrieved July 10, 2016, from https://journal.uptimeinstitute.com/data-center-outages-incidents-industry-transparency/
  3. 3. www.cet-power.com 3 an acceptable down time of nearly nine hours per year. While this amount of time may seem acceptable or reasonable, the person or team responsible may disagree and argue that 9 hours would seem like an eternity. Availability can be improved by enhancing the existing critical infrastructure. Enhancement 1: adding power feeding equipment A common example of additional equipment is the generator (or genset). Unfortunately, the generator is a weak link in the overall power infrastructure. Consider the following problems: 1. The generator is usually in “Standby Mode”, and therefore, must be started. 2. It relies on gas or diesel fuel. The fuel quality must be monitored. Old fuel or fuel with excessive contaminants reduces or eliminates its ability to “start” the engine. 3. The generator requires considerable and expensive maintenance. If this maintenance is not performed or is not performed on a regular schedule, the generator may not start when required. 4. Lastly, even if the generator is maintained and is started regularly, if not started and stressed with a load, it may not support the load when required. These concerns may be compounded in large facilities by the fact that there may be more than one generator. Enhancement 2: adding batteries When the generator and batteries are considered together, the target of increased availability from 99.99% to 99.999% is realized. However, the batteries can be another weak link. There are a number of factors that affect the operational capability of batteries. One of the prime factors is the lack of maintenance. Very few organizations employ rigorous monitoring and testing of batteries. Additionally, battery life is affected by temperature and humidity. For every additional 15 degrees above 77 degrees Fahrenheit, battery life is reduced by 50%. Therefore, batteries can fail when least expected. Enhancement 3: deploying a UPS The UPS, or Uninterruptible Power Supply, will handle the AC load and the available battery plant (rectifier and batteries) will handle the DC load. (See the figure #1 below). This presents several issues. The UPS has a set of batteries contained within its infrastructure. Therefore, you have a set of batteries in the UPS (not visible here) and a second set of batteries for being used for backup for the DC load. It is also likely these are different types of batteries, exhibiting different operational characteristics and life expectancies. Another problem in the above figure is if either set of batteries fail, you lose either the AC or the DC load. Unfortunately, we need both loads available at the same time.
  4. 4. www.cet-power.com 4 An additional disadvantage of the standard UPS is the amount of time it will run after a power failure. The amount of time it will continue to operate is generally measured in minutes. This is a specific function of the industrial batteries integrated to support the UPS. If the outage is longer in duration than the battery is able to support, the entire network is down. The questions start to add up. What is the best way to prevent outages? What is the best way to engineer a solution to ensure reliable, robust and resilient power to the mission critical network?
  5. 5. www.cet-power.com 5 An innovative solution: 48V DC modular No-break technology from CE+T Power Users can now deploy CE+T Power’s 48V DC No-Break technology. This technology uses a modular approach to construct a system that is resilient and can grow as needed. While there are some functional similarities with a UPS system, the CE+T Power solution also has some differences which make the 48V No-Break superior in operation. The CE+T Power solution uses a proprietary TSI or Twin Sine Innovation which allows it to operate in a manner similar to a double conversion UPS. Figure 1 - AC load and DC load Figure 2 - 48V No Break UPS The red box represents the modular building block of the CE+T Power Inverter. It is taking AC input power from the grid (the black line) to power the AC load. In this configuration, it is operating in AC Primary mode. It is also connected to the DC output from the rectifier. The rectifier, provided by one of several CE+T Power partners is also charging the batteries. In the event of a grid failure, the CE+T Power No Break solution takes the DC input from the backup batteries and supports the AC load.
  6. 6. www.cet-power.com 6 The technology that supports the CE+T Power solution is shown in the block diagram below. There are two inputs shown on the left side of the diagram and one output shown on the right side of the diagram. The two inputs take input source voltage and convert each to a high DC voltage. That high DC voltage is “stored” in the DC buffer shown in the middle. The output starts on the right side of the DC buffer as a high DC voltage and is converted or switched to an AC voltage to support the AC load, shown on the right side of the diagram. All communication across individual modules is overseen be the redundant DSPs or Digital Signal Processors. Figure 3: functional diagram of TSI The following is a discussion of the different attributes when considering a conventional UPS (Uninterruptible Power Supply) versus a technologically superior solution, such as CE+T Power’s 48V No-Break UPS solution. This discussion and the comparison matrix (Annex 1) shows the different attributes. BOOST AC / DC AC DC AC DC / AC DC Buffer DSPDC / DC CLICK HERE TO DOWNLOAD THE FULL WHITEPAPER

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