Teraloop is a Finnish company located in Espoo, Finland. Established in 2014, Teraloop provides energy storage solutions that can help stabilize the natural intermittency of solar and wind energy and provide protection against power quality issues and power outages. Teraloop has developed a kinetic energy storage system that helps unlock the potential of renewable energy while reducing expenses. Teraloop’s goal is to achieve prosperity through access to sustainable energy.
AMB technology needed for Teraloop’s product development
The typical battery degrades fast due to high current charge/discharge cycles even with short periods. Flywheel, which is a kinetic energy storage device, shaves these fluctuations with its virtually unlimited cycles and allows battery use only for long cycles. With this approach, the lifetime of the batteries is significantly increased.
The main challenge with a kinetic energy storage system is to make sure that the energy is stored long enough while there is high back-to-back efficiency and minimum idle losses. Thus, it is extremely important to minimize friction losses. Even friction between the rotor surface and the surrounding air should be. Air friction is minimized by rotating the energy-storing hubless flywheel in a vacuum. One of the advantages of using active magnetic bearings is frictionless operation. Therefore, it was a natural step for Teraloop to adapt AMB technology from SpinDrive for their flywheel.
Figure 1. Teraloop’s flywheel
High-efficiency and maintenance-free AMB solutions provided by SpinDrive
For high-speed machines, bearings are critical as they need to meet special requirements such as tolerating high speed. Conventional bearings in most cases are not able to operate in such conditions.
In this cooperation, SpinDrive optimized the radial magnetic bearing to minimize the rotor losses in vacuum. In addition, SpinDrive helped to design a sensor solution that can be operated in such conditions and is economically attractive.
The Magma X800 magnetic bearing controller from SpinDrive enables the flywheel to adapt to the changing environment. The hubless outer-rotor flywheels provide more energy density compared to the inner-rotor solution. On the other hand, the high rotor diameter results in significant rotor expansion. This causes changes in the dynamic behavior of the system.
The other challenge is the high gyroscopic effect proportional to the rotational speed that adds coupling between degrees of freedom. All these features require a computationally intensive and adaptive controller that can take all this into account and safely operate the system in a wide speed range. Magma X800 suits best the purpose with its powerful cutting-edge software features.
Figure 2. SpinDrive expert doing commissioning at Teraloop
Unbeatable achievements with AMBs
Flywheels and hybrid storage systems make electric vehicles (EV) fast and ultra-fast charging easier and more economical to realize since no major upgrade to the grid is required and the charging times are reduced.
Teraloop has been developing a P250 kinetic energy storage system for short power outages and voltage/frequency support, microgrids, data centers, and other industrial settings. They were looking for a higher-power product that could store more energy and provide more power output.
With the active magnetic bearing solution provided by SpinDrive, the rotor of the flywheel can be rotated at a higher speed limited by the used material, which improves the performance of the flywheel and allows it to increase the power and energy density of the system.
SpinDrive’s Magma X800 AMB controller offered a stable operation at a high-efficiency point. With the advantage of being maintenance-free, active magnetic bearings have a much longer lifetime than conventional bearings. “For the flywheel application, another important factor is the energy consumption of the AMB. With Spindrive we have been able to design an AMB system with the power draw of only 50W during normal operation, which is a great result for a 250kW machine. This furthermore contributes to the operational cost of the whole system.” says Markus Merilä Chief Engineer of Teraloop.
“Active magnetic bearings are five times more energy efficient than mechanical bearings and also require less maintenance as there is no physical contact. SpinDrive is specialized in providing tailored active magnetic bearing solutions, which is important for Teraloop due to the unique hubless design of the flywheel” Merilä explains.
“We appreciate the flexibility of SpinDrive to provide engineering support and their ability to tailor the system based on our requirements. Their know-how in AMB systems helped us to overcome system development challenges.” Merilä added.
Figure 3. Average rotor orbits are shown for the nominal speed range. The black circle representing backup bearing contact point
A continuous partnership is desired by both parties
Teraloop and SpinDrive have built mutual understanding and trust through long-term cooperation. Both parties have an intention to continue exploring more opportunities to mitigate the acceleration of climate change together. The aim of SpinDrive is to provide world-class AMBs for industrial partners and support them in achieving their goals with a sustainable solution.
If you are interested in more details of this project or have any questions regarding deploying active magnetic bearings for your machines, feel free to contact:
Ole Martola, Business Development Director