Assessing the benefits of adjustable speed hydro machines

Summary form only given. This paper presents the adjustable speed hydro (ASH) machine concept as an alternative for obtaining better utilisation of power networks. Transmission lines appearing as bottlenecks with respect to power demand may increase their transfer capacity as ASH machines are introduced in the network. This is achieved by a quick and precise regulation of rotor currents and thereby active and reactive power out of the machine. During faults in the network, these properties map be utilised to maintain near constant power production and torque equilibrium. This in turn gives less speed deviation and better ability to control the network behaviour. Hence, the ASH machine can give a considerable contribution to the network both during and after serious conditions in the power system.