Conference programme

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Delegates are invited to meet and discuss with the poster presenters during the poster presentation sessions between 10:30-11:30 and 16:00-17:00 on Thursday, 19 November 2015.

Lead Session Chair:
Stephan Barth, ForWind - Center for Wind Energy Research, Germany
Pablo Otero Vazquez Alstom Wind , Spain
(1) Alstom Wind , Barcelona, Spain

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Presenter's biography

Biographies are supplied directly by presenters at EWEA 2015 and are published here unedited

Mr. OTERO has been working in the wind industry for almost ten years. He studied Industrial Engineering at University of A Coruña (Spain). He shared studies and worked four years at ECOTECNIA (windmill manufacturer) working in various roles and has been involved in development of electrical cabinets for windmills auxiliary systems. Two years ago he works at GE RENEWABLES ENERGY in Barcelona as Electrical design drives and automation. He has been involved in many wind projets including the Pitch System


Poster Download poster (12.11 MB)


Double winding in motor Pitch Applications. Safety, Reliability and Performance


The Pitch system has the task of managing the rotor speed and also the aerodynamic braking of the turbine. These are fundamental task without which the turbine can´t operate. At stake through this component, the safety, availability and performance of the WT.


Today Pitch Systems are usually driven electrically or hydraulically. Thanks to the advancement of technology AC drives, as well as high efficiency motors we are seeing an increase use of electric technology in Pitch applications. The use of this technology allows systems are simpler and more efficient.

Main body of abstract

With this goal, we have implemented in the motor two or more sets of windings that can operate individually or together. Each winding motor will associate a converter. The easiest choice will be composed by a double winding motor and two converters.
The mode of operation may be individual, only one or two synchronized. In the way of working together one of the converters will works as a master and the other with following of torque control. We can get a balanced distribution of currents and torques over both windings. This will happen as well in all operating modes including Safety Run mode. In this case the signal torque set point and control of Safety Run must meet requirements PLd (EN ISO 13843-1). To avoid problems with the lack of synchronization between windings.
Each inverter will receive position of the motor rotor to optimize flux and therefore the applied torque. Also it will have a temperature sensor to assess the current status of the windings.
The slot stator configuration may be common or individual for each winding, the number of poles is usually the same for each winding. The rotor configuration may be a common rotor in case of common slots or individual rotor in the other case.
The implementation of this system redound the operation of the Pitch converter, which is the most critical element of the system. Also will allow more torque capacity in the motor shaft.


Using a double winding motor enables increased safety, availability and performance, thanks to the implementation of two electronic converters to a double winding motor.
Safety is increased to redound the drive that manages the motor (Two converters), allowing go to feather of the blade with a single or both converters. It allows withstand loads unfavorable loads due to distribution between the two converters that manage the motor according to the requirements PLd (EN ISO 13849-1).
Availability increases with fewer components need to operate; switches, contactors, etc. Furthermore it allows the turbine to operate in degraded mode, in case of failure in one of the converters. Possibility of the option of working in a sleep mode, using only two converters if is necessary.
Increases the performance of the machine thanks to the availability of more current to accelerate and decelerate the blade and to move higher torques.

Learning objectives
Concepts that should be transmitted are as follows:
- Knowledge of the functionality of the Pitch System.
- Types and general characteristics of Pitch Systems.
- Features and operation of the proposed solution.
- Problems mitigated on the proposed solution.
- Improvements to the system, that applies for the proposed solution.