Safety mechanisms, wake up and shutdown methods in distributed power installations
A distributed power system including multiple DC power sources and multiple power modules. The power modules include inputs coupled respectively to the DC power sources and outputs coupled in series to form a serial string. An inverter is coupled to the serial string. The inverter converts power input from the serial string to output power. A signaling mechanism between the inverter and the power module is adapted for controlling operation of the power modules.
1. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules based on one or more start conditions.
2. The distributed power system of claim 1 , wherein the signaling mechanism is configured to, in response to determining that the one or more start conditions have been satisfied, control the plurality of DC modules to operate in a normal mode.
3. The distributed power system of claim 1 , wherein one of the one or more start conditions comprises waiting a preset time period after the inverter is coupled to an electrical grid.
4. The distributed power system of claim 1 , wherein one of the one or more start conditions comprises having a minimum preset voltage at an input of the inverter.
5. The distributed power system of claim 1 , wherein the signaling mechanism is configured to, in response to determining that there is at least a minimum load at an output of the inverter, control the plurality of DC modules to operate in a normal mode.
6. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, and wherein the signaling mechanism is configured to superimpose a signal on output of the plurality of DC modules.
7. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, wherein the signaling mechanism includes a switch integrated with the inverter, and wherein the switch is configured to modulate a signal onto output of the plurality of DC modules.
8. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules;
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules; and
a plurality of receivers, each integrated with a respective DC module of the plurality of DC modules, wherein each receiver is configured to receive a signal from the inverter.
9. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules;
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules; and
a detection mechanism, in each of the plurality of DC modules, configured to detect a signal at a frequency of an electrical grid.
10. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules;
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, and wherein the inverter is coupled to an electrical grid; and
a detection mechanism, in each of the plurality of DC modules, configured to detect a signal from the electrical grid and wherein the signal is detected at a higher frequency up converted from a frequency of the electrical grid.
11. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules;
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, and wherein the inverter is coupled to an electrical grid; and
a detection mechanism, in each of the plurality of DC modules, configured to detect signals at a switching frequency of the inverter.
12. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, wherein each of the plurality of DC modules is configured to operate in a safety mode, and wherein during the safety mode, power output from each DC module is limited.
13. The distributed power system according to claim 12 , wherein each of the plurality of DC modules includes a detection mechanism, wherein during operation, the detection mechanism is configured to detect a signal from the inverter and, based on the signal, the operation of the plurality of DC modules is varied from the safety mode to a normal mode for converting power of the plurality of DC power sources to the power output of the plurality of DC modules.
14. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, and wherein output of all of the plurality of DC modules is coupled in series.
15. A distributed power system, comprising:
a plurality of DC power sources;
a plurality of DC modules, each coupled to a respective one of the plurality of DC power sources;
an inverter coupled to the plurality of DC modules; and
a signaling mechanism between the inverter and the plurality of DC modules, wherein the signaling mechanism is configured to control operation of the plurality of DC modules, and wherein a first subset of the plurality of DC modules is coupled in series, a second subset of the plurality of DC modules is coupled in series, and the first subset is coupled to the second subset in parallel.
16. A method comprising:
operating a power conversion circuit, to convert power input from a plurality of DC power sources, in a safety mode limiting power from the power conversion circuit;
monitoring a signal from an inverter of the power conversion circuit, wherein the inverter outputs the signal indicating that one or more start conditions have been satisfied; and
in response to detecting the signal from the inverter, operating the power conversion circuit in a normal mode for applying converted power to an electrical grid.
17. The method of claim 16 , wherein one of the one or more start conditions comprises waiting a preset time period after the inverter is coupled to the electrical grid.
18. The method of claim 16 , wherein one of the one or more start conditions comprises having a minimum preset voltage at an input of the inverter.
19. The method of claim 16 , wherein the inverter is configured to output the signal indicating that an output of the inverter has a minimum load.
20. A method comprising:
operating a power conversion circuit, to convert power input from a plurality of DC power sources, in a safety mode limiting power from the power conversion circuit;
monitoring a signal from an inverter of the power conversion circuit; and
in response to detecting the signal from the inverter, operating the power conversion circuit in a normal mode for applying converted power to an electrical grid, wherein the safety mode is characterized by having less than ten milliamperes of current flow at less than ten Volts.
21. A method comprising:
operating a power conversion circuit, to convert power input from a plurality of DC power sources, in a safety mode limiting power from the power conversion circuit;
monitoring a signal from an inverter of the power conversion circuit; and
in response to detecting the signal from the inverter, operating the power conversion circuit in a normal mode for applying converted power to an electrical grid, wherein operating the power conversion circuit in the normal mode further comprises increasing the power input to the inverter by operating a plurality of DC modules, comprised in the power conversion circuit, in the normal mode.
22. The method according to claim 21 , further comprising a step of:
upon detecting the signal and prior to the operating of the plurality of DC modules in the normal mode, slowly ramping up voltage of the plurality of DC modules.
23. The method according to claim 21 , wherein the normal mode of the plurality of DC modules includes controlling a maximum peak power input to the plurality of DC modules.
24. The method according to claim 21 , further comprising coupling outputs of all of the plurality of DC modules in series.
25. The method according to claim 21 , further comprising coupling outputs of a first subset of the plurality of DC modules in series, coupling outputs of a second subset of the plurality of DC modules in series, and coupling the first subset to the second subset in parallel.
26. The method according to claim 21 , further comprising, during the safety mode, limiting a current from the plurality of DC modules to less than ten milliamperes and a voltage to less than ten Volts.