System and method for testing an energy storage device of a wind turbine pitch system

A system for testing capacity of at least one energy storage device of a pitch drive mechanism to drive a first rotor blade of a wind turbine, the wind turbine connected to a power grid, the system comprising:

• at least one sensor configured for monitoring a rotor position of the first rotor blade;
• a controller communicatively coupled to the at least one sensor, the controller comprising at least one processor configured to perform one or more operations, the one or more operations comprising:
• defining a rotor position range for implementing a first test procedure for the at least one energy storage device, the rotor position range including rotor positions in which a motor torque of a pitch drive motor of the pitch drive mechanism acts against a predetermined threshold of gravity during pitching of the first rotor blade toward a feathered pitch angle;
• when the rotor position of the first rotor blade enters the rotor position range, initiating the first test procedure, the first test procedure comprising:
• pitching the first rotor blade to a first pitch angle via the power grid;
• pitching the first rotor blade from the first pitch angle toward the feathered pitch angle via the at least one energy storage device;
• measuring at least one operating condition of the at least one energy storage device during pitching of the first rotor blade toward the feathered pitch angle via the at least one energy storage device;
• and,
• determining a capacity of the at least one energy storage device to drive the first rotor blade based on the at least one operating condition of the at least one energy storage device.

A method for testing capacity of a battery of a pitch drive mechanism to drive a rotor blade of a wind turbine, the wind turbine connected to a power grid, the method comprising:

• determining a rotor position of the rotor blade;
• pitching the rotor blade towards a power position via the power grid;
• defining a rotor position range for implementing a first test procedure for the battery, the rotor position range including rotor positions in which a motor torque of a pitch drive motor of the pitch drive mechanism acts against a predetermined threshold of gravity during pitching of the first rotor blade toward a feathered pitch angle;
• monitoring a rotor position of the first rotor blade;
• when the rotor position of the first rotor blade enters the rotor position range, pitching the rotor blade towards a feathered position via the battery;
• measuring a battery voltage of the battery and a pitch speed of the rotor blade during pitching;
• and
• determining a capacity of the battery at least one energy storage device to drive the rotor blade based on the rotor position and the battery voltage or the pitch speed.