Network topology for monitoring and controlling a solar panel array
Embodiments of a network topology for monitoring and controlling an array of solar panels include an intelligent node adapted to send and receive data and commands by at least two redundant means of communication. An intelligent node includes a solar panel, a node controller, a photovoltaic module, a bypass relay, a bypass bus, PLC and wireless communication interfaces for redundant means of communication, and sensor and actuator interfaces for monitoring and controlling the intelligent node. A PV module in the intelligent node may selectively be bypassed without interrupting network communications. Some embodiments include a plurality of intelligent nodes electrically connected serially into a chain of nodes and further connected to a gateway. Other embodiments include a plurality of chains of nodes connected to an inverter and a transformer, thereby defining an area. Additional embodiments further include a central server in communication with a plurality of areas.
1. An apparatus for monitoring and controlling a photovoltaic array, comprising:
at least two redundant means of communication adapted for sending and receiving data and commands;
a node controller comprising:
a bypass relay control line;
a first bidirectional port electrically connected to a first of said at least two redundant means of communication; and
a second bidirectional port electrically connected to a second of said at least two redundant means of communication;
an output terminal;
a photovoltaic module output line; and
a bypass relay electrically connected to said bypass relay control line, comprising:
a first switching state comprising an electrical connection between said photovoltaic module output line and said output terminal; and
a second switching state wherein said photovoltaic module output line is electrically disconnected from said output terminal,
wherein said node controller is adapted to select said first and second switching states of said bypass relay, and a voltage on said photovoltaic module output line is combined with a voltage on said input terminal when said first switching state is selected.
2. The apparatus of claim 1 , further comprising:
an input terminal;
a photovoltaic module input line electrically connected to said input terminal; and
said second switching state of said bypass relay further comprising an electrical connection between said input terminal and said output terminal.
3. The apparatus of claim 1 , further comprising:
a circuit for measuring a voltage on said photovoltaic module output line;
a circuit for measuring a current on said photovoltaic module output line; and
said node controller further comprising:
a first input electrically connected to an output of said circuit for measuring a voltage; and
a second input electrically connected to an output of said circuit for measuring a current.
4. The apparatus of claim 1 , wherein a first of said at least two redundant means of communication comprises a wireless transceiver.
5. The apparatus of claim 1 , wherein a first of said at least two redundant means of communication comprises a circuit for exchange of data and commands over a power line.
6. The apparatus of claim 1 , further comprising:
an energy storage module for providing electrical power to said node controller; and
a charger having an input electrically connected to said output terminal and an output electrically connected to said energy storage module.
7. The apparatus of claim 1 , further comprising a device for measuring temperature, said device for measuring temperature having an output electrically connected to said node controller.
8. The apparatus of claim 1 , further comprising a device for measuring an amount of solar radiation, said device for measuring an amount of solar radiation having an output electrically connected to said node controller.
9. The apparatus of claim 1 , further comprising a device for measuring surface cleanliness, said device for measuring surface cleanliness having an output electrically connected to said node controller.
10. The apparatus of claim 1 , further comprising a device for measuring reflectance, said device for measuring reflectance having an output electrically connected to said node controller.
11. The apparatus of claim 1 , further comprising a device for measuring azimuth angle, said device for measuring azimuth angle having an output electrically connected to said node controller.
12. The apparatus of claim 1 , further comprising a device for measuring elevation angle, said device for measuring elevation angle having an output electrically connected to said node controller.
13. The apparatus of claim 1 , wherein said node controller may alternatively receive data and commands from said first redundant means of communication, said second redundant means of communication, or from both of said first and said second redundant means of communication.