Method of forecasting for solar-based power systems
The method of forecasting for solar-based power systems ( 10 ) recognizes that no single solar irradiance forecasting model provides the best forecasting prediction for every current weather trend at every time of the year. Instead, the method trains a classifier to select the best solar irradiance forecasting model for prevailing conditions through a machine learning approach. The resulting solar irradiance forecast predictions are then used to allocate the solar-based power systems ( 10 ) resources and modify demand when necessary in order to maintain a substantially constant voltage supply in the system ( 10 ).
1. A computer-implemented method of forecasting for solar-based power systems, comprising the steps of:
(a) providing a non-transitory computer-readable medium having embodied thereon a program, which when executed by a computer, causes the computer to execute a method of forecasting for solar-based power systems, the method comprising the steps of:
i. measuring a first series of current solar irradiance parameters with sensors for a defined geographical region over predetermined time intervals to form a data set, wherein the measurements comprise measuring direct normal irradiance (DNI), global horizontal irradiance (GHI) and diffuse horizontal irradiance (DHI);
ii. selecting a window size defining a number of past measurements and future forecast predictions to be made from the number of past measurements;
iii. partitioning the data set into successive and adjacent time series training data sequences of the selected window size;
iv. applying a plurality of different forecasting methods to the time series training data sequences to obtain future forecast predictions from each of the forecasting methods;
v. comparing the future forecast predictions of each of the forecasting methods to measured data to obtain a corresponding error rate associated with each of the methods, given the time series training data sequences;
vi. assigning the forecasting method with the lowest error rate as the forecasting class for the time series training data sequences;
vii. repeating steps i through vi to train a classifier to determine an optimal forecasting class for different time series training data sequences;
viii. using the sensors to measure a second series of current solar irradiance parameters;
ix. using the classifier to determine the optimal forecasting class for the second series of current solar irradiance parameters;
x. making future forecast predictions from the second series of current solar irradiance parameters using the optimal forecasting class;
xi. predicting solar-based power system demands and generating capacities based upon the future forecast predictions made in step (j); and
xii. making adjustments in the solar-based power system demands and stored energy in order to maintain a substantially constant voltage supply for the defined geographic region.
2. The method of forecasting for solar-based power systems as recited in claim 1 , wherein the step of measuring the first and second series of current solar irradiance parameters comprises measuring in one minute intervals.
3. The method of forecasting for solar-based power systems as recited in claim 1 , further comprising the step of applying data filtering to the data set generated in step i.
4. The method of forecasting for solar-based power systems as recited in claim 1 , wherein the plurality of forecasting methods comprise a persistence method and a support vector regression method.
5. A computer-implemented method of forecasting for solar-based power systems, comprising the steps of:
providing a non-transitory computer-readable medium having embodied thereon a program, which when executed by a computer, causes the computer to execute a method of forecasting for solar-based power systems, the method comprising the steps of:
measuring solar irradiance parameters with sensors for a defined geographical region over predetermined time intervals to form a data set, wherein the measurements comprise measuring direct normal irradiance (DNI), global horizontal irradiance (GHI) and diffuse horizontal irradiance (DHI);
selecting a window size defining a number of past measurements and future forecast predictions to be made from the number of past measurements;
partitioning the data set into successive and adjacent time series training data sequences of the selected window size;
applying a different autoregressive forecasting method to each of the time series training data sequences to obtain future forecast predictions;
training a classifier to determine an optimal forecasting class for the different time series training data sequences;
predicting solar-based power system demands and generating capacities based upon the future forecast predictions; and
making adjustments in the solar-based power system demands and stored energy in order to maintain a substantially constant voltage supply for the defined geographic region.
6. A non-transitory computer-readable medium having embodied thereon a program, which when executed by a computer, causes the computer to execute a method of forecasting for solar-based power systems, the method comprising the steps of:
measuring solar irradiance parameters with sensors for a defined geographical region over predetermined time intervals to form a data set;
selecting a window size defining a number of past measurements and future forecast predictions to be made from the number of past measurements;
partitioning the data set into successive and adjacent time series training data sequences of the selected window size;
applying a different autoregressive forecasting method to each of the time series training data sequences to obtain future forecast predictions;
training a classifier to determine an optimal forecasting class for the different time series training data sequences;
predicting solar-based power system demands and generating capacities based upon the future forecast predictions; and
making adjustments in the solar-based power system demands and stored energy in order to maintain a substantially constant voltage supply for the defined geographic region.