Methods and apparatus to protect solar power plants

• US 9,871,380 B1
• Filed: 01/18/2016
• Issued: 01/16/2018
• Est. Priority Date: 03/15/2013
• Status: Active Grant

• Current Assignee: CyboEnergy, Inc.
• Original Assignee: CyboEnergy, Inc.
• Inventors: Cheng, George Shu-Xing, Mulkey, Steven L.
• Primary Examiner(s): Houston, Adam
• Application Number:
  US14/997,990
• Time in Patent Office: 729 Days
• Field of Search: 307 52
• CPC Class Codes: G06V 20/52 Surveillance or monitoring of activities, e.g. for recognising suspicious objects recognising microscopic objects G06V20/69
• CPC Class Codes: G08B 13/1409 for removal detection of electrical appliances by detecting their physical disconnection from an electrical system, e.g. using a switch incorporated in the plug connector
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/40 Synchronising a generator for connection to a network or to another generator
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02M 3/04 by static converters
• CPC Class Codes: H02M 7/44 by static converters
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: H04N 7/188 Capturing isolated or intermittent images triggered by the occurrence of a predetermined event, e.g. an object reaching a predetermined position signal generation from motion picture films H04N5/253
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A method and apparatus is disclosed that can monitor the solar power inverters in real-time both day and night, and generate surveillance alarms and actions when a solar power inverter is removed or disconnected from the AC powerline for unknown reasons. It offers a low cost and reliable surveillance means to help guard a residential-scale, commercial-scale, or utility-scale solar power system in real-time at all times.

Claims

1. A method of providing online surveillance to protect a solar power plant with solar panels and solar power inverters, comprising:

a) enabling the solar power inverters to keep powerline communication with a powerline communication device;

b) monitoring the status of the solar power inverters in real-time; and

c) triggering surveillance alarms and actions when a predetermined number of the solar power inverters are detected to lose the communication at a plurality of preselected times;

wherein each of the solar power inverters comprises;

i) at least two DC input channels, each of which comprises a DC-DC boost converter, measurement circuits, supporting circuits, and cables and connectors to connect to a solar panel;

ii) an AC power output port arranged to supply AC power to the electric grid through an external AC powerline;

iii) a DC power combiner connected to said DC-DC boost converters for combining the DC output from all DC-DC boost converters;

iv) a DC power supply connected to the DC power combiner, an AC/DC power supply connected to the external AC powerline, and a power supply selector, arranged to work together and supply DC power to internal electronic circuits of the inverter either by the DC power supply with input power from one or more solar panels or by the AC/DC power supply with input power from the grid through the external AC powerline; and

v) a digital microcontroller connected to the DC-DC boost converters and the power supply selector, said digital microcontroller arranged to measure input voltage and current to calculate DC input power for each input channel, constructed to run the inverter in a normal mode or a night mode based on calculated DC input power; and

keep powerline communication of the inverter to the outside world as long as the inverter is connected to the external AC powerline.

2. An online surveillance system for protecting a solar power plant, comprising:

a) one or more solar power inverters connected to one or more solar panels through DC input channels, said one or more solar power inverters also being connected to an AC powerline for delivering AC power to the electric grid;

b) an AC power service panel configured to combine one or more AC power branch circuits and deliver AC power to the electric grid through a main AC powerline, each said branch circuit being connected with a plurality of solar power inverters and solar panels;

c) one or more powerline communication devices, connected to an AC branch circuit or the main AC powerline isolated by a circuit breaker, each said powerline communication device being configured to communicate with a plurality of preselected solar power inverters through the AC powerline; and

d) one of more computers, network routers, alarms, cameras, Internet, Internet servers, Internet terminal devices, and police dispatch service stations, configured to activate surveillance alarms and actions when a predetermined number of solar power inverters are detected to lose the communication at a plurality of preselected times;

wherein each of the one or more solar power inverters comprises;

i) at least two DC input channels, each of which comprises a DC-DC boost converter, measurement circuits, supporting circuits, and cables and connectors to connect to a solar panel;

ii) an AC power output port arranged to supply AC power to the electric grid through an external AC powerline;

iii) a DC power combiner connected to said DC-DC boost converters for combining the DC output from all DC-DC boost converters;

iv) a DC power supply connected to the DC power combiner, an AC/DC power supply connected to the external AC powerline, and a power supply selector, arranged to work together and supply DC power to internal electronic circuits of the inverter either by the DC power supply with input power from one or more solar panels or by the AC/DC power supply with input power from the grid through the external AC powerline; and

v) a digital microcontroller connected to the DC-DC boost converters and the power supply selector, said digital microcontroller arranged to measure input voltage and current to calculate DC input power for each input channel, constructed to run the inverter in a normal mode or a night mode based on calculated DC input power; and

keep powerline communication of the inverter to the outside world as long as the inverter is connected to the external AC powerline.

3. The surveillance system of claim 2, wherein said powerline communication device is a powerline communication gateway or a powerline communication server.

4. The surveillance system of claim 2, in which the said powerline communication device is programmed with an alarm action routine to iteratively:

a) upon the detecting the loss of communication with one of solar power inverters, check if it is a new solar power inverter that has just lost the communication;

b) if a) is negative, exit;

c) if a) is positive, check if the system lost communication with 2 or more inverters;

d) if c) is negative, send a message to inform related personnel and exit;

e) if c) is positive, check if the utility room has lost AC power;

f) if e) is positive, send a message to inform related personnel and exit;

g) if e) is negative, check if the alarm is in “

On Guard”

mode;

h) if g) is negative, send a message to inform related personnel and exit;

i) if g) is positive, check if the time is between a predetermined first and second time;

j) if i) is negative, send a message to inform related personnel and exit;

k) if i) is positive, perform one or more of activating surveillance cameras, sounding alarms or horns, informing security guards, dispatching police, and sending messages and e-mails to assigned personnel; and

l) run an Alarm Acknowledgement and Reset Subroutine.