Vertical axis wind microturbine (TRL 7)

Short summary A group of Italian entrepreneurs with a multidisciplinary technical expertise founded a start up to develop, in collaboration also with the academic world, an innovative vertical axis wind microturbine (TRL 7) which has already recorded a 30% performance improvement over state of the art technology during the first tests in a wind tunnel laboratory. The start up is looking for investors and corporates interested in the final development and commercialisation of the wind turbine on the market.

Full description The Italian start up has developed a vertical wind microturbine with axial development consisting of a central shaft equipped with anchoring tools with an inner blade of the dynamic resistance type (Savonius) and an outer blade of the dynamic lift type (Darrieus), both coupled to the central shaft but disjointed from each other. An electric generator (dual production system) is associated with each blade. The two blades couple/uncouple via a dynamic joining device (active electromechanical clutch) controlled by an adaptive control system. Specifically, the dynamic joining part cooperates with the drive part so that the rotation of the outer blade is independent of the rotation of the inner blade, keeping both the former and the latter operationally connected to the electric generation system. The active control system, controlled by a proprietary algorithm, activates/deactivates the joining system according to the wind conditions. Specifically, the drag blade is used as the starter of the lift blade, but upon reaching the optimal speed, the two blades disengage and rotate independently so as to optimise the power coefficient of each blade. Subsequently, the junction component is activated as the stabiliser of the lift blade, thereby optimising the power output for both generators in all wind speeds. Stabilisation takes place through two actions: as a booster in the case of wind drops and a consequent reduction in the revolutions of the lift blade, or as an aerodynamic brake if wind conditions take the lift blade out of speed, discharging the excess mechanical energy produced to the drag blade, effectively recovering mechanical energy to be transformed into electrical energy. With this structure, improved generative systems (generators) can be combined to take advantage of the optimal production curve based on the characteristics of the blade to which they are connected. In order to support this structure an adaptive control system has been developed to intervene on the following components: - electrical generating equipment - emergency stop - coupling / decoupling of the rotors - stabiliser of the two aerodynamic elements (Darrieus and Savonius blades). This control operates through an intelligent system controlled by proprietary algorithms and allows the maximum power output of both rotors to be achieved through a very efficient response to sudden changes in wind characteristics. In fact, such a system ensures a greater capacity to capture kinetic energy over time: thus, the concept of capturability is introduced, that is the ability of the plant to collect kinetic energy over a period of time. Finally, the microturbine is complemented by an innovative transformation system that, unlike standard inverters, guarantees very high efficiency. This system, developed in collaboration with a leading global technology industry, consists of a series of drives controlled by a proprietary software that optimises the power curve control (Maximum Power Point Tracker MPPT) with 15 ms PID. Thanks to its programmability, it is therefore possible to equip the microturbine with an adaptive control system for each environmental condition in which it is installed. In addition, the microturbine is equipped for the collection and processing of data on environment, air quality, pollution, which can be of interest to local entities and research centres. The start up has already invested 350K € and thanks to the grants received and calls won has to its credit additional 250K €, which have allowed the project to reach TRL 7. The business model mainly consists of the implementation of the wind microturbine with a constant activity of R&D. The first wind microturbines will be sold on the market directly to the first customers in a limited number for a preliminary market exposure and the setting up of the first user base. Subsequently, the production will be decentralised at third parties.

Advantages and innovations With such a microturbine, we will no longer deal with rated power, but with captured power over a period of time (capturability). The dynamically coupled dual Darrieus/Savonius technologies and the torque-controlled dual generators allow the microturbine to optimise the overall efficiency in the range between 4 and 12 m/s. Scientific literature shows that use of wind turbines in a fixed mode leads to the deterioration of power coefficients, with a 40% reduction in performance. Due to the independent coaxial axes, the proposed microturbine does not have this problem. The power coefficients of the individual blades are optimised, increasing the mechanical power produced. The electromechanical coupling component, controlled by an intelligent and adaptive system, enables the intelligent startup of the turbine, the discharge of excess power, the reduction of passive blade adjustment mechanisms that are subject to wear and consequent shorter life cycle and decrease in efficiency. The turbine features a dual-generator configuration. It is shown that the RPM of the Darrieus differs significantly from that of the Savonius: this implies that for the various hybrid solutions, the generator never works on the optimal output curve. With this new feature, however, the two generators are optimised for the blades used. Scientific literature points out that the use of solar inverters converted to wind has a very low performance under turbulent conditions due to the inefficiency of the MPPT algorithms. A new technology was developed so that to allow, through the use of specific drives for electrical conversion, the active control of blade speeds to ensure maximum efficiency in conversion. These drives are managed by proprietary software that ensures the control of power curves with a 100-fold improvement in response time as compared to standard inverters. The combination of these solutions guarantees along the entire transformation chain an efficiency of 98% of the power product
Contact / source: NEXT EEN Widgets (europa.eu)