Methods and systems for detecting shading for solar trackers
A solar tracker system including a tracker apparatus including a plurality of solar modules, each of the solar modules being spatially configured to face in a normal manner in an on sun position in an incident direction of electromagnetic radiation derived from the sun, wherein the solar modules include a plurality of PV strings, and a tracker controller. The tracker controller includes a processor, a memory, a power supply configured to provide power to the tracker controller, a plurality of power inputs configured to receive a plurality of currents from the plurality of PV strings, a current sensing unit configured to individually monitor the plurality of currents, a DC-DC power converter configured to receive the plurality of power inputs powered from the plurality of PV strings to supply power to the power supply, and a motor controller, wherein the tracker controller is configured to track the sun position.
1. A method of operating a solar tracker system, the method comprising:
providing a tracker controller, the tracker controller configured to receive electrical power from a plurality of solar modules, each solar module configured to receive electromagnetic radiation from a Sun, the plurality of solar modules arranged to form a plurality of photovoltaic (PV) strings, each PV string comprising at least two solar modules;
detecting a plurality of power signals generated by the plurality of PV strings and communicated electrically from each of the plurality of PV strings to a plurality of power inputs of the tracker controller;
determining a tilt angle associated with each PV string;
determining that a portion of the plurality of PV strings is shaded based on one or more of the detected power signals being less than a threshold; and
changing the tilt angle of one or more of the PV strings in response to determining that a portion of the plurality of PV strings is shaded.
2. The method of claim 1 , further comprising a learning algorithm configured to predict a position of the sun, the learning algorithm trained by training data and the detected power signals from the plurality of PV strings, the training data comprising at least one of a time of year, a geography, and a plurality of sun positions stored in a memory, yielding a stored time of year, geography, and plurality of sun positions.
3. The method of claim 2 , wherein the determining that a portion of the plurality of PV strings is shaded includes using the learning algorithm, and wherein the learning algorithm comprises a machine learning algorithm.
4. The method of claim 3 , wherein the machine learning algorithm uses, as learning data, at least one of the stored time of year, geography, and plurality of sun positions to predict in advance what portion of the plurality of PV strings may be shaded.
5. The method of claim 4 , wherein the tracker controller tracks the Sun based on a prediction from the machine learning algorithm.
6. The method of claim 1 , wherein the tilt angle of one or more of the plurality of PV strings is further changed based on detecting a maximum output power.
7. The method of claim 1 , further comprising determining a priority between a maximum output power and the determining if any portion is shaded.
8. The method of claim 1 , wherein the shading includes south-north shading.
9. The method of claim 1 , wherein the shading includes east-west shading.
10. A solar tracker system comprising:
one or more controllers configured to receive electrical power from a plurality of photovoltaic (“PV”) strings, each of the plurality of PV strings comprising at least two solar modules, the solar modules configured to receive electromagnetic radiation from a Sun, the one or more controllers comprising:
a processor;
a power supply configured to supply power to the one or more controllers; and
a plurality of power inputs configured to receive a plurality of power signals communicated electrically from each of the PV strings to the one or more controllers,
wherein the processor is configured to determine that a portion of the PV strings is shaded based on one or more of the received power signals being less than a threshold, and
wherein the processor is configured to change a tilt angle of one or more of the PV strings in response to determining that a portion of the plurality of PV strings is shaded.
11. The solar tracker system of claim 10 , wherein the one or more controllers is further configured to determine the tilt angle associated with the one or more of the PV strings before changing the tilt angle of the one or more of the PV strings in response to determining that a portion of the plurality of PV strings is shaded.
12. The solar tracker system of claim 10 , wherein the one or more controllers further comprises a memory configured to store at least one of:
a time of year;
a geography; and
a plurality of Sun positions,
wherein the processor is configured to execute a learning algorithm to predict whether a portion of the plurality of PV strings will be shaded based on one or more of the stored time of year, the stored geography, and the stored plurality of Sun positions.
13. The solar tracker system of claim 10 , wherein the tilt angle of one or more of the plurality of PV strings is further changed based on detecting a maximum output power.
14. The solar tracker system of claim 13 , wherein changing the tilt angle of one or more of the plurality of PV strings is based on determining a priority between the maximum output power and the determining if any portion of the plurality of PV strings is shaded.
15. A method of operating a solar tracker system, the method comprising:
providing a tracker controller for a plurality of solar modules, each solar module configured to receive electromagnetic radiation from a Sun, the plurality of solar modules arranged to form a plurality of photovoltaic (PV) strings, each PV string comprising at least two solar modules, the tracker controller configured to control a tilt angle of each of the plurality of PV strings;
detecting a plurality of power signals generated by the plurality of PV strings and communicated electrically from each of the plurality of PV strings to a plurality of power inputs of the tracker controller;
determining the tilt angle associated with each PV string;
determining that a portion of the plurality of PV strings is shaded based on one or more of the detected power signals being less than a threshold; and
changing the tilt angle of one or more of the PV strings in response to determining that a portion of the plurality of PV strings is shaded.