Photo voltaic (PV) array-shedding and storage system
View Patent ↗The present invention provides for a photovoltaic system and circuit having array shedding functionality. The system and circuit, in general, have at least two photovoltaic strings, at least one inverter; and, an array shedding and harvesting functionality configured to monitor the inverter and either disconnect or connect inputs of the at least two photovoltaic strings as needed to produce power for the at least one inverter or to produce power for storage. The array shedding and harvesting functionality is preferably integrated between photovoltaic (PV) strings and the output of the inverter. Various embodiments provide for sensors integrated on each of the inputs of a power assembly combiner, current sensors used to sense current provided on each of multiple inputs from power sources (PV arrays or combiners), and direct current (DC) contactors used to control connection of power source inputs.
1. A photovoltaic system comprising:
an electrical power source configured to provide at least two electrical power outputs;
at least one inverter configured to input electrical power corresponding to the at least two electrical power outputs of the electrical power source;
circuitry including a switch configured to controllably switch a destination of the electrical power corresponding to each output of the electrical power source, respectively;
a sensor configured to determine a voltage of the electrical power input to the at least one inverter; and
a controller configured to control diversion of electrical power from one or more of the at least two electrical power outputs of the electrical power source to the electrical power input to the at least one inverter in response to the power of the input to the at least one inverter dropping below a predetermined power threshold.
2. The photovoltaic system of claim 1 , further comprising the storage as a destination of the electrical power to store electrical power for later use.
3. The photovoltaic system of claim 2 , further comprising:
one or more current sensors coupled to the at least two electrical power outputs of the electrical power source;
wherein the sensor includes a voltage sensor coupled to an output bus;
wherein the controller is further configured to receive signals from the one or more current sensors and voltage sensor and control the diversion in response to the signals from either the one or more current sensors or the voltage sensor, or both of the one or more current sensors and voltage sensor, indicating that the power of the input to the at least one inverter exceeds the predetermined threshold.
4. The photovoltaic system of claim 1 , wherein the at least two electrical power outputs comprise a plurality of photovoltaic strings, wherein the photovoltaic system further includes at least one string combiner coupled between the at least one inverter and the plurality of photovoltaic strings.
5. The photovoltaic system of claim 4 , wherein the circuitry and sensor are integrated within one of the at least one string combiner.
6. The photovoltaic system of claim 1 , wherein the at least two electrical power outputs comprise a plurality of photovoltaic strings; and wherein the photovoltaic system further includes at least two string combiners coupled to the plurality of photovoltaic strings and at least one array combiner between the at least two string combiners and the at least one inverter.
7. The photovoltaic system of claim 6 , wherein the circuitry and sensor are integrated within the at least one array combiner.
8. The photovoltaic system of claim 1 , wherein the circuitry and sensor are located in a separate panel.
9. The photovoltaic system of claim 8 , wherein the circuitry and sensor are connected via a remote panel.
10. The photovoltaic system of claim 1 , wherein the circuitry and sensor are integrated within one of the at least one inverter.
11. A photovoltaic array shedding and harvesting circuit comprising:
at least one current sensor for sensing each input of at least two photovoltaic strings,
at least one voltage sensor connected to a common output bus, and
an inverter switch configured to integrate an inverter and a program logic control to monitor and control the inverter and connect each input of the at least two photovoltaic strings as needed to control diversion of power from one or more of the at least two photovoltaic strings to a storage in response to a value of the power input to the inverter exceeding a predetermined upper threshold.
12. The circuit of claim 11 , wherein when the value of the power input to the inverter exceeds the predetermined upper threshold, the program logic control will open a first contactor to direct power from a first one of the at least two photovoltaic strings to the storage.
13. The circuit of claim 12 , wherein when the value of the power input to the inverter again exceeds the predetermined upper threshold after opening the first contactor, the program logic control will open a second contactor to direct power from a second one of the at least two photovoltaic strings to the storage.
14. The circuit of claim 11 , wherein when the value of the power input to the inverter is below a predetermined lower threshold, the program logic control will close a first contactor, add a first power input from one of the at least two photovoltaic strings and divert power to the inverter.
15. The circuit of claim 14 , wherein when the value of the power input to the inverter is below the predetermined lower threshold after adding the first power input, the program logic control will close a second contactor, add a second power input from one of the at least two photovoltaic strings and divert power to the inverter.
16. The circuit of claim 11 , wherein the photovoltaic array shedding and harvesting circuit is integrated into an array shedding and harvesting photovoltaic system.
17. The circuit of claim 11 , wherein array shedding and harvesting functionality of the photovoltaic array shedding and harvesting circuit is integrated within the inverter.
18. The circuit of claim 17 , wherein the array shedding and harvesting functionality is located in a separate panel.