A flywheel in a wind turbine rotor for inertia control

Abstract

In this paper, a flywheel energy storage that is an integral part of a wind turbine rotor is proposed. The rotor blades of a wind turbine are equipped with internal weights, which increase the inertia of the rotor. The inertia of this flywheel can be controlled by varying the position of the weights, i.e. by positioning them closer to the center of rotation (closer to the hub) or closer to the tip of the blades. The simulation model used in this study is introduced briefly. The equation system of the flywheel is set up. Finally, simulations of different scenarios show the performance of this controllable flywheel. The conclusion is that the proposed system can mitigate transients in the power output of wind turbines. Hence, it can support the frequency control in a power system by contributing to the power system inertia.

Load analysis of hydraulic‐pneumatic flywheel configurations integrated in a wind turbine rotor

“…As explained in previous work of the authors, the FW generates an additional torque from the change in angular momentum . This FW torque, T fw , can also be expressed in terms of Coriolis force, F cor , acting on the variable radius of the FW, R var , as described in Equation .…”

“…As described in previous work of the authors, the fluid mass should be moved between the piston accumulators within a certain time, t m , which defines the mass flow . The mass flow is constant within the piston accumulators and the hydraulic tube.…”

“…The general idea of the FW system, the physical description, and its performance in terms of providing rapid controllable power to the power system and mitigating loads on the WT were previously presented . A FW system was designed for the 5‐MW WT developed by the National Renewable Energy Laboratory (NREL) and the 61.5‐m rotor blade developed by Brian R. Resor (hereafter referred to as “Resor blade”).…”

Effects of decreasing synchronous inertia on power system dynamics—Overview of recent experiences and marketisation of services

“…Their conclusion is that contribution of variable renewable energy resources is not necessary to maintain adequate values of primary reserve and inertia even in high (71%‐82% and 66%‐79%, respectively) share of wind generation. In contrast, Jauch proposes a flywheel energy storage system integrated into a wind turbine to support frequency control of the power system . A comprehensive review on the most important issues was presented by Tielens and Van Hertem .…”

“…In contrast, Jauch proposes a flywheel energy storage system integrated into a wind turbine to support frequency control of the power system. 53 A comprehensive review on the most important issues was presented by Tielens and Van Hertem. 26 The authors have taken the perspective of the TSO to identify challenges and potential solutions and have proposed a new definition of inertia.…”