Five years ahead of the future...

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1 ELEKTROMOTOREN \ Permanent-Magnet-Motoren Five years ahead of the future... Energy-saving Motors Achieve a New Efficiency Class Fig.1. Stephan Hensel The rise in energy costs in recent years has made the development and use of energy-saving motors increasingly important. The current state of the art in this field is motors that meet the efficiency requirements for the highest class, IE4, as defined in IEC TS One example of the latest generation is the SPRiPM permanent magnet motor that can be controlled by a V1000 or A1000 drive. This innovation implements the high efficiency requirements (Super Premium Efficiency) of the relevant regulations for energy-related products five years before these regulations become mandatory. It also features a high starting torque and fast start up. Development of energy-saving motors had already started in Japan by the early 1990s. However, the relevant standards for energy efficiency in industrial applications weren t established until the EU directive for energy-using products and electric motors (EC640/2009) went into effect in This directive applies to electric motors in the output range from 0.75 kw to 375 kw. The international IEC standard initially defined three efficiency classes: from the lowest, IE1, to the highest, IE3. As of 2011, all newly installed electric motors must at least meet the IE2 standard. The next step is that all motors with an output of 7.5 kw to 375 kw must meet the requirements of the IE3 class or the IE2 class in combination with a drive by In the final phase, starting in 2017, this requirement also applies to smaller motors with 0.75 kw or more. These requirements are intended to reduce the total energy consumption in Europe approximately five percent by 2020.

2 While most European industrial companies are currently thinking about how to implement the IE2 requirements, innovative electric motor providers have already introduced the first models in the efficiency class IE4. The requirements for this class are defined in the current version of the standard, IEC TS However, this is still a prestandard. The previous standard, IEC , still defines the classes 1 to 3, but only refers to the limit values for the efficiency of asynchronous machines. In contrast, the new version not only defines the requirements for the new efficiency class 4, but also expressly applies to all types of electric motors [Footnote 1]. In particular, these include permanent magnet motors. High energy efficiency One example of the latest generation of energy-saving motors is YASKAWA s SPRiPM (Super Premium IPM Motor, pronounced like supreme ) permanent magnet motor (Fig. 1). This motor is offered as a drive package in combination with the V1000 or A1000 drive and covers an unusually broad range of IE4-compliant applications. Test runs at the University of Coimbra, which provided scientific support during creation of the energy-related product regulations, confirmed this fact. Currently, a total of eight different versions are available: for motor shaft outputs of 0.4 kw to 15 kw, for a nominal speed of 1500 or 3000 revolutions per minute (rpm), with standard axle heights of 71 to 112 cm and standard foot or flange mounting (B3/B5). All models are CE and IP55-compliant.

3 This extremely energy-efficient innovation not only implements the high efficiency requirements (Super Premium Efficiency) of the relevant EU directives five years before they become mandatory, but also exceeds them with the class IE4+. The energy savings are so high that it s worth switching straight to today s highest class instead of using the required IE2 motors: the additional costs of the initial investment generally pay for themselves after around two years. After this point, every kilowatt hour of energy saved directly cuts costs. Even in comparison with the former highest class of IE3, there are significant cost advantages, as this example shows: in an air-conditioning system, 100 pumps with 4 kw each run around the clock. Run by IM-type IE3 motors from YASKAWA with an efficiency of 83.1 percent, these pumps use some 4,216,600 kwh per year. The SPRiPM with IE4+, on the other hand, has an efficiency of 92 percent. That means the savings in this example are 407,900 kwh. At an electricity price of 0.13/kWh, this would result in 53,000 euros of savings on energy costs each year. Compact design and high torque In addition to its high energy efficiency, the SPRiPM features an extremely compact design to save space inside machines. The structure of permanent magnet motors alone makes them considerably smaller and lighter than comparable induction motors. With this new development, the dimensions are even smaller. Each new motor is up to 40 percent more compact than a comparable induction motor. This is equivalent to a frame that is two standard sizes smaller, allowing for more compact machine designs. In addition, the SPRiPM weighs 50 percent less and has 60 percent less inertia than an induction motor. This means it can start and stop 60 percent faster. This innovative motor also features a very high torque, even in the lower speed range. The IPM motor reaches its rated torque of 100 percent as soon as it starts, virtually from the first revolution on. Even at 150 rpm (5 percent of the rated torque) the torque can be 150 percent. IE4 drive package for a wide variety of applications The motor can be combined with YASKAWA s proven V1000 drive to provide a highperformance IE4 drive package with standardised technology for a wide variety of

4 applications. YASKAWA s V1000 drive offers a solution as reliable as it is efficient for precisely and safely controlling permanent magnet motors. No feedback is necessary, making this drive package sturdier and more affordable. Introduced as the smallest compact drive in the world, the V1000 takes up very little space. You can achieve even higher performance with a premium drive from the A1000 series: in this configuration, the drive can detect the exact position of the motor using a special control method without an encoder or sensors and position it precisely. This allows torques of over 200 percent at a speed of 0. Thanks to the integrated self-tuning function, setting up the A1000 drive takes just three minutes. Areas of application and key advantages The SPRiPM s high starting torque ensures faster motor acceleration for shorter cycle times. First and foremost, however, it makes the motor ideal for applications that require a high starting torque to break large masses free, for example when starting a screw conveyor with a viscous mass of plastic. Other examples include conveyors, large fillers, extruders, compressors, hydraulic pumps and other systems in the beverage industry. But the potential areas of application also include refrigeration and air-conditioning technology, the construction industry, production, petrochemistry, refineries, the steel and automotive industries, medical technology and the construction of test benches. For example, extruders work in a process with a continuous torque. The motor accelerates in less than one second and features high dynamic responsiveness without requiring a gear box. For screw compressors, this model offers both powerful torque in the lower speed range and very high motor speeds of up to 400 Hz. For applications with variable torques, such as fans, the special flying start function is particularly advantageous: in the event of a power failure, the fan wheel continues to turn. The SPRiPM and the V1000 cover the speed range down to 10 Hz to allow optimal restarting. The motor s low noise level is particularly evident in applications with fans, because the blades of the fans would magnify any noise. Naturally, the benefits of saving energy also apply to the applications specified. These benefits are especially relevant for systems in continuous operation, such as compressors and conveyors. In these applications, the new motor reduces not only life-cycle and operating costs, but also CO2 emissions.

5 [Footnote 1:] The original wording of the standard states that: The IE4 energy efficiency class is not limited to three-phase cage-induction motors like the classes IE1, IE2 and IE3 of IEC Instead, IE4 is intended to be used with all types of electrical motors, particularly with converter-fed machines (both cage-induction and other types like permanent-magnet synchronous-motors, etc.). Author: Stephan Hensel BE in Automation Technology