System and method for providing yaw backup to a wind farm

Patent metadata

Field	Value
Publication number	US-9677540-B2
Application number	US-201314073892-A
Country	US
Kind code	B2
Filing date	Nov 7, 2013
Priority date	Nov 29, 2012
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

A yaw backup system is provided. The yaw backup system includes an energy storage medium for storing auxiliary power. The yaw backup system also includes a yaw controller for coordinating delivery of power from the energy storage medium to a yaw motor for controlling a yaw angle of a wind turbine during grid loss conditions. The yaw controller executes the steps of receiving wind direction signals over time from a sensor, altering a tolerance level of a wind turbine based on changes in the wind direction signals over time and controlling delivery of power to the yaw motor from the auxiliary power of the energy storage medium based on the tolerance level to control the yaw angle for reducing a load on the wind turbine induced by wind.

First claim

The invention claimed is:

1. A yaw backup system comprising:
an energy storage medium for storing auxiliary power;
a yaw controller for coordinating delivery of power from the energy storage medium to a yaw motor for controlling a yaw angle of a wind turbine during grid loss conditions by executing steps of:
receiving wind direction signals over time from a sensor;
determining a wind direction rate of change based on the wind direction signals;
selecting a tolerance level from a plurality of predetermined and stored tolerance levels, wherein the selected tolerance level correlates to the determined wind direction rate of change with respect to time, the tolerance level comprising a duty cycle at which power is supplied to the yaw motor for a defined range of wind direction rate changes;
switching to a different tolerance level when the wind direction rate of change exceeds the defined range for the selected tolerance level; and
controlling the delivery of power from the energy storage medium to the yaw motor based on one of the selected tolerance level or the different tolerance level to maintain the yaw angle in a predefined angular dead band limit relative to wind direction for reducing a load on the wind turbine induced by wind.

2. The yaw backup system of claim 1 , wherein the yaw controller is further configured for executing a step of receiving wind speed signals from the sensor and determining a wind speed rate of change based on the wind speed signals, and wherein the step of switching to a different tolerance level is additionally based on the wind speed rate of change.

3. The yaw backup system of claim 1 , wherein the sensor comprises an anemometer.

4. The yaw backup system of claim 1 , further comprising a line side converter electrically coupled to the energy storage medium.

5. The yaw backup system of claim 4 , wherein the yaw controller is further configured for coordinating delivery of power from the energy storage medium to the line side converter during grid loss conditions.

6. The yaw backup system of claim 1 , wherein the energy storage medium comprises a battery.

7. The yaw backup system of claim 1 , wherein the energy storage medium has capacity for providing power to additional auxiliary components of the wind turbine.

8. A wind farm comprising:
a plurality of wind turbines for generating wind power and transmitting the wind power to a power grid, where the wind turbines are electrically coupled to each other;
a plurality of yaw motors, each yaw motor for controlling a yaw angle of a respective wind turbine of the plurality of wind turbines
yaw backup systems coupled to the respective wind turbines in the wind farm for controlling delivery of power to the respective yaw motors to control the respective yaw angles of the respective wind turbines during a grid loss condition, wherein each of the yaw backup systems comprises:
an energy storage element for storing auxiliary power;
a yaw controller for executing the steps of:
receiving wind direction signals over time from a sensor;
determining a wind direction rate of change based on the wind direction signals;
selecting a tolerance level from a plurality of predetermined and stored tolerance levels, wherein the selected tolerance level correlates to the determined wind direction rate of change with respect to time, the tolerance level comprising a duty cycle at which power is supplied to the yaw motor for a defined range of wind direction rate changes;
switching to a different tolerance level when the wind direction rate of change exceeds the defined range for the selected tolerance level;
computing an auxiliary power level of the energy storage element coupled to the respective wind turbine;
comparing the computed auxiliary power level with a predefined auxiliary power level of the energy storage element coupled to the respective wind turbine; and
controlling the delivery of power from the energy storage element to a respective yaw motor for maintaining the yaw angle of the respective wind turbine in a predefined angular dead band limit relative to wind direction for reducing a load on the respective wind turbine induced by wind, and

wherein the yaw controller controls the delivery of power from the energy storage element of the respective wind turbine if the computed auxiliary power level is greater than the predefined auxiliary power level for the respective wind turbine, or from an energy storage element of a different wind turbine coupled to the respective wind turbine if the computed auxiliary power level is less than the predefined auxiliary power level for the respective wind turbine based on the tolerance level to control the yaw angle of the respective wind turbine.

9. The wind farm of claim 8 , wherein each sensor comprises an anemometer.

10. The wind farm of claim 8 , wherein each of the yaw backup systems further comprises a line side converter electrically coupled to the respective energy storage element.

11. The wind farm of claim 10 , wherein each of the yaw controllers is further configured for coordinating delivery of power from the energy storage element to the line side converter during the grid loss condition.

12. The wind farm of claim 8 , wherein each energy storage element comprises a battery.

13. The wind farm of claim 8 , wherein each yaw controller is further configured for executing a step of receiving wind speed signals from the sensor, and wherein the step of switching to the different tolerance level is additionally based on the wind speed signals or changes in the wind speed signals over time.

Assignees

• Gen Electric

Inventors

• Burra Rajni Kant
• Ganireddy Govardhan
• Abate Victor Robert
• Longtin Keith Andrew
• Wiegman Herman Lucas Norbert
• Delmerico Robert William

Classifications

• F03D7/0204 Primary

  for orientation in relation to wind direction · CPC title

• F05B2270/321

  Wind directions · CPC title

• F05B2270/107

  to cope with emergencies · CPC title

• F05B2270/337

  Electrical grid status parameters, e.g. voltage, frequency or power demand · CPC title

• F05B2260/845

  Redundancy · CPC title