Monitoring of distributed power harvesting systems using DC power sources
A monitoring system and method for monitoring performance of individual powers sources in a distributed power source system. A monitoring module is coupled to each of the power sources, or to each string of serially connected power sources, to monitor and collect data regarding current, voltage, temperature and other environmental factors at the power source. The collected data is transmitted over a power line to a central analysis station for analysis. Data collected from each source indicates malfunction or degradation at the source. Comparison of data collected from adjacent sources filters for environmental factors impacting neighboring sources such as cloudy days for a solar panel. Comparison of data collected from the same source at different times indicates soiling or degradation of the source with time or periodic events such as a moving shade from an adjacent building.
1. An apparatus, comprising:
a first power source connected to a power line;
a first monitoring module comprising a timer, wherein the first monitoring module is configured to collect performance data of the first power source starting from a time when the first power source starts to output power to the power line above a power threshold amount after waking up from a sleep state as detected by the first monitoring module;
a first transmitter configured to transmit the performance data wirelessly;
a first controller configured to control the first transmitter to transmit the performance data of the first power source wirelessly when an elapsed time period from initialization of the timer reaches a transmission time period of the first transmitter;
a second power source connected to the power line;
a second monitoring module comprising a second timer, wherein the second monitoring module is configured to collect performance data of these second power source starting from a time when the second power source starts to output power to the power line after waking up from a sleep state as detected by the second monitoring module;
a second transmitter configured to transmit the performance data of the second power source wirelessly; and
a second controller configured to control the second transmitter to transmit the performance data of the second power source wirelessly when an elapsed time period from initialization of the timer reaches a transmission time period of the second transmitter;
wherein the first controller is configured to control the first transmitter to transmit the performance data of the first power source wirelessly when an elapsed time period from initialization of the timer reaches a transmission time period of the first transmitter added to a first random time increment,
wherein the second controller is configured to control the second transmitter to transmit the performance data of the second power source wirelessly when an elapsed time period from initialization of the second timer reaches a transmission time period of the second transmitter added to a second random time increment, and
wherein the first and second random time increments are different from each other to lessen a possibility of collisions in transmissions of performance data of the first power source and the second power source.
2. The apparatus of claim 1 , wherein the first monitoring module further comprises a randomizer configured to include random time increments in the transmission time period of the first power source.
3. The apparatus of claim 1 , further comprising:
a current measurement module configured to collect current data of the first power source; and
a voltage measurement module configured to collect voltage data of the first power source.
4. The apparatus of claim 1 , further comprising a temperature sensor configured to sense temperature data of the first power source.
5. The apparatus of claim 1 , wherein the first monitoring module further comprises an arc detection module configured to detect arcing at the first power source.
6. The apparatus of claim 1 , further comprising a memory configured to store the performance data accumulated since the initialization of the timer.
7. The apparatus of claim 1 , further comprising:
a communication module configured to transmit the performance data to a communication translator.
8. A method, comprising:
monitoring, by a monitoring module that includes a microcontroller, power generation of a first power source;
when power generation of the first power source passes a threshold after having awaken from a sleep state as detected by the monitoring module, initializing a timer and collecting performance data of the first power source;
monitoring an elapsed time period of the timer from initialization of the timer;
generating a first random time increment to be applied for a transmission time period of the first power source;
determining, by a first controller, the transmission time period of the first power source by adding the first random time increment to a periodic transmission time of the first power source;
determining whether an elapsed time period of the timer has reached the transmission time period of the first power source;
in response to determining that the elapsed time period has reached the transmission time period of the first power source, transmitting collected performance data of the first power source wirelessly;
generating a second random time increment to be applied for a transmission time period of a second power source connected to a same power line as the first power source; and
determining, by a second controller, a transmission time period for transmitting performance data of the second power source wirelessly by adding the second random time increment to a periodic transmission time of the second power source,
wherein the first and second random time increments are different from each other to lessen a possibility of collisions in transmissions of performance data of the first power source and the second power source.
9. The method of claim 8 , wherein transmitting collected performance data comprises:
transmitting, to a communication translator in communication with a plurality of power sources, the collected performance data.
10. The method of claim 9 , wherein collecting performance data further comprises storing the performance data in memory, and wherein transmitting the collected performance data comprises transmitting the collected performance data accumulated since a previous transmission of performance data.
11. The method of claim 8 , wherein collecting performance data comprises measuring at least one of output voltage and output current.
12. The method of claim 8 , wherein transmitting the collected performance data comprises:
transmitting the collected performance data with a unique identifier of the first power source and a unique identifier of a second power source different from the unique identifier of the first power source.
13. The method of claim 8 , further comprising:
detecting for wideband noise; and
in response to detecting wideband noise above a threshold, transmitting an interrupt message.
14. A system, comprising:
a plurality of panel units connected to a communication line, wherein each panel unit comprises:
a power source;
a monitoring module configured to collect performance data of the power source;
a transmitter configured to transmit the performance data wirelessly; and
a controller configured to control the transmitter to transmit the performance data wirelessly; and
a communication translator configured to receive the performance data from each of the plurality of panel units wirelessly, wherein the controller of each panel unit is configured to avoid transmission collisions with controllers of other panel units by applying different time increments to be added to transmission times for transmission of the performance data for each of the plurality of panel units wirelessly.
15. The system of claim 14 , wherein the monitoring module comprises a timer, and wherein the controller is configured to transmit the performance data based on an elapsed time period of the timer and a transmission time period associated with the panel unit of the controller.
16. The system of claim 15 , wherein the monitoring module further comprises a randomizer configured to include random time increments in the transmission time period for each of the plurality of panel units wirelessly so as to lessen a possibility of collisions due to transmissions of performance data of the respective plurality of panel units.
17. The system of claim 14 , wherein the communication line comprises a power line that carries electrical power generated by each of the plurality of panel units.
18. The system of claim 14 , further comprising:
a central analysis station configured to detect for faults, wherein the communication translator is configured to transmit the performance data to the central analysis station.
19. The apparatus of claim 3 , further comprising:
a digital control module configured to receive the current data of the first power source collected by the current measurement module, and to receive the voltage data of the first power source collected by the voltage measurement module, and to maintain an input power of a converter that converts power output by the first power source at a maximum power point.
20. The method of claim 9 , further comprising:
maintaining, based on the collected performance data, an input power of a converter that converts power output by the first power source at a maximum power point.