Systems and methods for advanced grid integration of distributed generators and energy resources
A circuit for a smart photovoltaic (PV) inverter system and the smart PV inverter system are described. The circuit includes one or more strings coupled to an electrical load. Each of the one or more strings further includes one or more string members coupled in series, where each of the one or more string members comprises a voltage source and an inverter. The circuit also includes a controller to receive an output from an operator controller and control the strings, where the controller is configured to control the strings by providing a function command to a first string member of each of the one or more strings based on the output from the operator controller. The voltage source may also receive an output from an energy output device. Further, the inverter may be configured to convert the output of energy output device into an energy source of electrical load.
1. A circuit for a smart photovoltaic (PV) inverter system, wherein the PV inverter system comprises a node of a distributed grid network, the circuit comprising:
one or more strings coupled to an electrical load, each of the one or more strings comprising one or more string members coupled to each other in series, wherein each of the one or more string members comprises a voltage source and an inverter; and
a controller to receive an output from an operator controller and control the one or more strings, wherein the controller is configured to control the one or more strings by providing a function command to a first string member of each of the one or more strings based on the output from the operator controller, wherein the output is based, at least in part, on a balancing requirement associated with a disturbance in a load of the distributed grid network; the first string member of each string calculates a current phase shift based on the function command; the first string member of each string adjusts a string current of each string based on the calculated current phase shift; and the one or more remaining string members of each string autonomously modifies an output voltage amplitude of the respective string member based on the adjusted string current.
2. The circuit of claim 1 , wherein the voltage source receives an output from an energy output device.
3. The circuit of claim 2 , wherein the inverter is configured to convert the output of the energy output device into an energy source of the e lec tric al load.
4. The circuit of claim 1 , wherein the electrical load further comprises a grid interface to couple the energy collection system to an electrical grid.
5. The circuit of claim 1 , wherein the controller is configured to determine a smart inverter robustness index of each string based on one or more inverter parameters.
6. The circuit of claim 5 , wherein the one or more inverter parameters include a conversion efficiency, a total harmonic distortion parameter, a maximum power point tracking effectiveness parameter, and a power factor compliance parameter.
7. The circuit of claim 1 , where each of the string members further comprises a distributed controller and a LC filter.
8. The circuit of claim 2 , wherein the energy output device includes a PV panel or other energy collection or generation device.
9. The circuit of claim 4 , wherein the first string member further comprises a current comparator.
10. A smart PV inverter system, comprising:
an operator center;
an electrical load;
one or more strings coupled to the electrical load, each of the one or more strings comprising one or more string members coupled to each other in series, wherein each of the one or more string members comprises a voltage source and an inverter; and
a controller to receive an output from the operator center and to control the one or more strings, wherein the controller is configured to control the one or more strings by providing a function command to a first string member of each of the one or more strings based on the output from the operator center, wherein the output is based, at least in part, on a balancing requirement associated with a disturbance in the electrical load; the first string member of each string calculates a current phase shift based on the function command; the first string member of each string adjusts a string current of each string based on the calculated current phase shift; and the one or more remaining string members of each string autonomously modifies an output voltage amplitude of the respective string member based on the adjusted string current.
11. The smart PV inverter system of claim 10 , wherein the voltage source receives an output from an energy output device.
12. The smart PV inverter system of claim 11 , wherein the inverter is configured to convert the output of the energy output device into an energy source of the electrical load.
13. The smart PV inverter system of claim 10 , wherein the electrical load further comprises a grid interface to couple the energy collection system to an electrical grid.
14. The smart PV inverter system of claim 10 , wherein the controller is configured to determine a smart inverter robustness index of each string based on one or more inverter parameters.
15. The smart PV inverter system of claim 14 , wherein the one or more inverter parameters include a conversion efficiency, a total harmonic distortion parameter, a maximum power point tracking effectiveness parameter, and a power factor compliance parameter.
16. The smart PV inverter system of claim 10 , where each of the string members further comprises a distributed controller and a LC filter.
17. The smart PV inverter system of claim 11 , wherein the energy output device includes a PV panel or other energy collection or generation device.
18. The smart PV inverter system of claim 10 , wherein the first string member further comprises a current comparator.