METHOD AND APPARATUS FOR ADVANCE LIFE ESTIMATION OF PITCH EMERGENCY STORAGE DEVICES IN WIND TURBINES
Publication Date: 2014-Sep-03
The IP.com Prior Art Database
The invention proposes a technique and apparatus therefore for testing pitch system and battery life without losing availability of wind turbine system and with enhanced safety. The technique and apparatus includes hardware to be capable of taking test on the turbine system without stopping the wind turbine, initiating blade test one by one instead of conducting test simultaneously and a software algorithm. Software algorithm keeps track of the battery performance and predict duration after which next test is required to be taken. Software algorithm with built in expert system / learning intelligence which tracks performance during every test and compares with all previous tests to conclude and predict approximate remaining life of the battery banks enables maintenance team to take proactive action.
The present invention relates generally to a wind turbine and more particularly to a technique and apparatus for estimating life of pitch emergency storage devices in wind turbines.
In general, electrical pitch system is a critical to wind turbine. Therefore, extra precaution is taken to keep it in a healthy state. The electrical pitch system includes certain devices to store energy to bring the pitch system to safer state during grid event, failure in control system, communication issues or similar emergency conditions.
In case, storage devices use chemical as media, such as batteries or ultracaps, among others, the storage devices prove to be the weakest link in the wind turbine system. Consequently, whole reliability of the wind turbine system is anchored by such storage devices.
Several issues are associated with such storage device, such as, the battery. For example, the battery is required to be periodically inspected physically and therefore preventive maintenance is required. Battery requires replacement after specific period of operation. Remaining life of battery is not accounted for after the battery is replaced. Usually, wind turbine operating conditions vary from site to site. As a result, battery is required to be utilized at all such variable conditions. There is also variation in quality of batteries from different manufacturers which accounts for different shelf life of batteries from different manufacturers. Also, probability of unsafe event is higher in case of utilization and maintenance of battery in pitch system of wind turbines.
A conventional technique includes pitch system testing which is initiated after bringing wind turbine in an inoperative state, i.e. testing is initiated after stopping the wind turbine. Figure 1 depicts a flow chart depicting process undertaken for carrying out pitch system testing.
As depicted in the above figure, pitch test is carried out by disconnecting power source from grid. Each of the blades is tested subsequently. After every blade pitch passes the test successfully, the wind turbine is started to work again. In case, any one of the blade pitch is found to have fault during testing, the wind turbine is stopped for further maintenance.
However, the above mentioned conventional technique allows wind turbine to lose availability during regular automatic testing, maintenance, and replacement of the battery in pitch system.
Therefore there is a need in the art to provide a technique for testing pitch system and battery life without losing availability of wind turbine system and with enhanced safety.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 depicts a flow chart depicting process undertaken for carrying out pitch system testing in a conventional technique.
Figure 2 depicts hardware components configured in the pitch system of wind turbine.
Figure 3 depicts a flowchart depi...