Wind turbine generator pitch control system

In a power generating system including a wind turbine driven generator producing alternating electrical power, said wind turbine having a wind driven rotor with a plurality of variable pitch angle blades;

• means for sensing a variable of operation of said system and producing a first signal indicative thereof,
• means for sensing the velocity of the wind driving said rotor and producing a second signal indicative thereof,
• means for producing a reference signal for said variable of operation,
• means for comparing said first signal with said reference signal to produce therefrom an error signal proportional to the difference therebetween,
• a first multiplier variable as a function of said second signal for producing from said error signal a proportional control signal,
• a second multiplier variable as a function of said second signal, and an integrator in series therewith, for producing from said error signal an integral control signal,
• a third multiplier variable as a function of said second signal, and a differentiator in series therewith, for producing from said error signal a derivative control signal,
• means for combining said proportional integral and derivative control signals to produce a blade pitch angle reference signal,
• blade pitch angle control means for regulating the pitch angle of said rotor blades,
• and means for connecting said first blade pitch angle reference signal with said blade pitch angle control means.

In a power generating system including a wind turbine driven synchronous generator producing alternating electrical power, said generator being adapted to supply said electrical power to that being conducted through a power transmission grid, said wind turbine having a wind driven rotor with a plurality of variable pitch angle blades, a control comprising:

• means responsive to a first variable of operation of said system and to the velocity of the wind driving said rotor for producing a first blade angle control signal,
• means responsive to a second variable of operation of said system and to the velocity of the wind driving said rotor for producing a second blade angle control signal;
• blade pitch angle control means receiving said first and second blade angle control signals,
• said blade pitch angle control means selecting said first blade angle control signal when the alternating electric power produced by said synchronous generator is not synchronized with the power in said power transmission grid, and selecting said second blade angle control signal when the alternating electric power produced by said synchronous generator is synchronized with the power in said power transmission grid,
• means for measuring the actual blade pitch angle of said rotor blades and producing an actual blade angle signal indicative thereof,
• comparator means comparing the selected blade angle control signal with said actual blade angle signal and producing a blade angle error signal,
• and blade pitch actuator means responsive to said blade pitch angle error signal for regulating the pitch angle of said rotor blades.

In a power generating system including a wind turbine driven synchronous generator producing alternating electrical power, said wind turbine having a wind driven rotor with a plurality of variable pitch angle blades, a control comprising:

• means responsive to first variable of operation of said system for producing a blade angle reference signal,
• means responsive to changes in the velocity of the wind driving said rotor for producing an anticipation blade angle reference signal as a function thereof,
• means for summing said anticipation blade angle reference signal with said blade angle reference signal,
• and a blade pitch angle control responsive to said summed blade angle reference signals for regulating the pitch angle of said rotor blades.

In a power generating system including a wind turbine driven generator producing alternating electrical power, said wind turbine having a wind driven rotor with a plurality of variable pitch angle blades, a control comprising:

• means for sensing the velocity of the wind driving said rotor and producing a wind velocity signal indicative thereof,
• means for producing a first blade angle reference signal scheduling a minimum blade angle relative to a blade pitch angle in which the blade is fully powered when said rotor is accelerating,
• means responsive to a variable of operation of said system for producing a second blade angle reference signal,
• means for selecting one of said blade angle reference signals,
• means for producing a signal indicative of the actual value of said blade angle,
• means for comparing said actual blade angle signal with said selected blade angle reference signal and producing therefrom a blade angle error signal,
• and blade pitch actuator means connected to receive said blade angle error signal and responsive thereto for regulating the pitch angle of said rotor blades.

In a power generating system including a wind turbine driven generator producing alternating electrical power, said wind turbine having a wind driven rotor with a plurality of variable pitch angle blades, a control comprising:

• means for generating a first signal indicative of wind velocity,
• means responsive to a condition of operation of said system for producing proportional, integral and derivative control signals,
• means responsive to said first signal for generating individual proportional, integral and derivative gain signals,
• means for multiplying said proportional, integral and derivative control signals respectively by said proportional, integral and derivative gain signals,
• means for combining said proportional, integral and derivative control signals, as modifed by said gain signals, to produce a blade angle reference signal,
• and means responsive to said blade angle reference signal for controlling the pitch angle of said blades.