Increasing wind power penetration in autonomous power systems through no-flow operation of Pelton turbines

• A novel operation mode for Pelton turbines, no flow, is presented.
• No flow operation of Pelton units allow the fastest possible power injection.
• A fast back-up power injection could be needed for wind power integration.
• Positive power ramps in hydropower plants are limited by penstock cavitation risk.
• This operation has been analysed in the renewable only El Hierro island power system.

The integration of wind power in power systems results in a reduction in greenhouse gas emissions. Thus, it has a positive environmental impact. However, the operation of these power systems becomes increasingly complex, owing mainly to random behaviour of the wind.In the case of island power systems, this problem is even more difficult. The traditional solution is to use diesel generators as an alternative power supply. For a wind-only power supply, an energy storage system is required. If the topography of the island makes possible the use of pumped storage hydropower plants, this is, nowadays, the most suitable energy storage system.This paper presents a novel method of Pelton turbine operation with no water flow, as a way to provide fast power injection in the case of an abrupt wind power decrease, or a wind-generator trip. This operation mode allows maximizing wind power penetration in a reliable and efficient way. This method has been validated by computer simulations, and will be tested during the commissioning of a combined wind-pumped storage power plant in an autonomous power system, on a small island.