Suzlon: Wind Park in Abla.
Featuring Two Power Converters per Windmill.

In a rough, windy area at the foot of the Spanish Sierra Nevada and at an elevation of about 1000 m lies the small community of Abla. Here, Suzlon set up a wind park with a total of 49 wind turbines of the type S88. For the generator control of this successful wind turbine we have been delivering power converters of the type PCS Green Line 2000 to Suzlon. In combination with our PCS Green Line 1000, the wind park in Abla satisfies the requirements of the re-enacted 2009 Renewable Energies Act.

Each windmill in Abla has an output of 2.1 MW, adding up to a total output of more than 100 MW for the wind park as a whole. With this kind of output, the facility could cover the power needs of a major city. At this wind park Suzlon also deploys the PCS Green Line 1000, a power converter model which will keep the system grid-connected even during brief voltage drops.

All over the world, Suzlon uses large numbers of the PCS Green Line 2000 model as main a component of this type of wind turbine. The simple, sturdy, and affordable solution is perfectly suited for wind turbines with a high output. It is looped via an asynchronous generator with slip-rings and electronically controlled additional rotor resistance.

PCS Green Line 2000 uses additional resistances in the rotor circuit to increase the slip range of an asynchronous generator to 16.7 percent of the nominal speed. An intermittently switching IGBT uses a diode rectifier to briefly short-circuit the rotor circuit in a certain duty cycle, thus briefly bridging the additional resistance. Depending on the duty cycle, this will obtain a mean value for the rotor resistance (chopper principle). In gusty winds, the rotor resistance is raised and the IGBT on time is decreased The additional energy in the flywheel mass of the drive train is saved as increased rotor speed. The increased output can be fed regulated into the grid, so that the drive train is exposed to a nearly constant torque. The pitch control returns the turbine to the predefined operating point. PCS Green Line 2000 was developed for Suzlon.

In recent years, power companies especially in Europa have demanded that wind parks must be capable of perfectly integrating into the power supply system. To this end, wind turbines need to remain connected to the grid for a certain time during power-outs, and must be able to maintain a reactive current. This is why we developed the compact PCS Green Line 1000 power converter, which has precisely these properties. For the duration of a system fault, the PCS Green Line 1000 is capable of generating a reactive current of up to 2,500 A, and thereby meets the requirements of the re-enacted Renewable Energies Act of 2009.

In Abla, the first installations are being raised, including the PCS Green Line 1000 along with the PCS Green Line 2000. For Suzlon, they enhance the company's competitive edge worldwide. For PCS, installing the Green Line products represents an important milestone en route to market leadership in power converters and electric equipment in the area of energy generation from regenerative sources. In early 2009, in conjunction with the installation of the first systems in Abla, PCS conducted a combined start-up service training sessions on site in Spain.

In total there are close to 1,500 Green Line converters active in Suzlon turbines. They cover all geographical positions and climate conditions - from the US to Spain and Northern China.