Power ramp rate control for renewable variable power generation systems

摘要

Certain embodiments of the invention may include systems and methods for controlling power ramp rates in renewable variable power generation systems. According to an exemplary embodiment of the invention, a method is provided for limiting power ramp rates. The method can include regulating collective power output of a plurality of variable energy sources by monitoring collective power output of the plurality of variable energy sources, and controlling collective power output of the plurality of variable energy sources with the plurality of power control signals.

主权项

1. A method for regulating collective power output of a plurality of variable energy sources, the method comprising:
monitoring collective power output of the plurality of variable energy sources; predicting future collective available power levels of the plurality of variable energy sources based at least in part on a first desired collective power ramp rate over a first time duration and a second desired collective power ramp rate over a second time duration, wherein the predicting of the future collective available power levels comprises:
establishing an average ramp rate for each time duration calculated as (Xn−Xn−N+1), wherein Xn is a power output at nth time period and N is the total number of time periods in the time duration;determining the future collective available power levels based on the average ramp rate; andcomparing the future collective available power levels to a settable ramp rate limit; based on the comparison, modifying, using at least one modifying function, the predicted collective available power levels based at least in part on limiting the rate of change of the predicted collective available power levels depending upon a direction of power change, wherein the at least one modifying function provides for faster slew rates when reducing power, to rapidly correct a transient condition, and slower slew rates when increasing power, wherein the at least one modifying function includes a low pass filter and a slew rate limiter; determining a power regulation setpoint based on the modified predicted collective available power levels; selecting a minimum of the collective available power levels and the power regulation setpoint; based at least in part on the selection, generating a net power command signal based at least in part on the modified predicted collective available power levels; generating a plurality of power control signals based at least in part on the net power command signal; and controlling collective power output of the plurality of variable energy sources with the plurality of power control signals to allow different collective rates of change of power output depending upon the direction of power change or upon previous power changes, wherein the collective rate of change of power output of the variable energy sources does not exceed a first desired collective power ramp rate over the first time duration.