Enclosure and message system of smart and scalable power inverters

• US 9,331,488 B2
• Filed: 06/29/2012
• Issued: 05/03/2016
• Est. Priority Date: 06/30/2011
• Status: Active Grant

• Current Assignee: CyboEnergy, Inc.
• Original Assignee: CyboEnergy, Inc.
• Inventors: Mulkey, Steven L., Cheng, George Shu-Xing, Martinez, Manuel
• Primary Examiner(s): Kaplan, Hal
• Application Number:
  US13/537,206
• Publication Number:
  US 20130002031A1
• Time in Patent Office: 1,404 Days
• Field of Search: 307/43, 307/82
• US Class Current: 1/1
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources
• 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 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• 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: Y02B 10/10 Photovoltaic [PV]
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

An enclosure design is disclosed to accommodate and support the unique features and capabilities of the Smart and Scalable Power Inverters or Mini-Inverters that have multiple input channels to easily connect to multiple solar PV panels, invert the DC power to AC power, and daisy chain together to generate AC power to feed the power grid or supply power to electrical devices. Further disclosed is a message system using LEDs (light-emitting diodes) mounted on the enclosure to indicate the system status and the status of each input channel of the Smart and Scalable Mini-Inverters.

Claims

1. A multiple channel power inverter, comprising:

a) at least two DC power input channels;

b) an AC power output port arranged to supply AC power to the AC power grid;

c) for each DC power input channel, a DC-DC boost converter arranged to convert the voltage of a DC power source to a higher DC voltage suitable for inversion;

d) a DC power combiner connected to said DC-DC boost converters for combining the DC output from all DC-DC boost converters and allowing the said DC-DC boost converters to connect in parallel so that all DC currents are added together;

e) a DC-AC inverter connected to said DC power combiner and, arranged to invert the DC power to AC power;

f) an internal AC powerline that combines the generated AC power with the external AC power from the power grid;

g) a load interface circuit connected to said DC-AC inverter and to said internal AC powerline, said load interface circuit being arranged to filter high-frequency components out of the said DC-AC inverter'"'"'s AC output;

h) a digital microcontroller connected to said DC-DC boost converter, DC-AC inverter, and load interface circuit, said microcontroller arranged to monitor the DC boost voltage, control the DC-DC boost converter, perform maximum power point tracking (MPPT), perform DC-AC inversion and AC power synchronization, monitor AC current and voltage for generated power amount and status, perform powerline communications, and perform logic controls such as AC powerline switching and isolation;

i) a powerline modem connected to said microcontroller and said internal AC powerline through an interface circuitry for transmitting and receiving performance data between said microcontroller and said power grid;

j) a line sensing circuit connected to said internal AC powerline and said microcontroller for detecting the phase and zero-crossing point of the incoming AC power from the power grid;

k) a solid state switch connected to said internal AC powerline and external AC powerline, and arranged to disconnect said internal AC powerline from the AC grid during the non-generation time;

l) a power supply connected to said DC power combiner and arranged to supply DC power to the electronic components of said power inverter; and

m) a message system connected to said digital microcontroller and arranged to indicate the status of the power inverter and the status of each input channel.

2. The inverter of claim 1, in which said message system comprises:

a) a plurality of LEDs (light-emitting diodes); and

b) an LED driver circuit controlled by the digital microcontroller and arranged to turn the LEDs to a predetermined color and/or pattern to indicate the status of the power inverter and the status of each input channel of the power inverter.

3. The inverter of claim 1, in which said message system includes a system status LED to indicate that

a) the inverter is working;

b) the inverter is working but has warnings;

c) the inverter has errors;

d) the AC power grid has errors; and

e) the inverter is off.

4. The inverter of claim 1, in which said message system further includes a channel status LED for each input channel to indicate that

a) the input channel is working;

b) the input channel has low input voltage;

c) the input channel has errors;

d) the input channel has warnings; and

e) the input channel is off.

5. The inverter of claim 1, in which the output of the power inverter is single-phase AC or three-phase AC.

6. The inverter of claim 1, further comprising an enclosure, the elements a) through m) being disposed in or on the enclosure.

7. The inverter of claim 6, in which the enclosure includes a metal case and the message system includes a system status LED, the inverter further comprising:

a) an AC input port grommet attached to the enclosure,

b) an AC input port cable extending through the grommet,

c) an AC input port connector connected to the AC input port cable,

d) an AC output port grommet attached to the enclosure,

e) an AC output port cable extending through the grommet,

f) an AC output port connector connected to the AC output port cable, and

g) a mounting bracket with mounting slots attached to the metal case.

8. The inverter of claim 6, in which the message system includes a channel status LED for each input channel, each input channel further comprising:

a) a DC grommet attached to the enclosure,

b) a pair of DC cables extending through the grommet,

c) a DC female connector connected to one of the DC cables, and

d) a DC male connector connected to the other DC cable.

9. The inverter of claim 1, in which the said digital microcontroller is programmed with a main program to iteratively:

a) turn on and off the inverter'"'"'s generation message based on the DC power source input and conditions of the inverter and AC powerline;

b) calculate the amount of power generated by the inverter during a predetermined period of time;

c) perform diagnostics for the inverter'"'"'s status and operation;

d) run redundancy routine for every input channel;

e) set the inverter'"'"'s unit address;

f) perform powerline communications; and

g) respond to queries from data gathering or acquisition devices to report the power statistics.

10. The inverter of claim 1, in which the message system includes a system status LED, and said digital microcontroller is programmed with an LED status subroutine invoked by a diagnosis mechanism to iteratively:

a) check a case number that indicates a predetermined status of the power inverter; and

b) turn the system status LED to a predetermined color and/or pattern based on the case number.

11. The inverter of claim 1, in which the message system includes a channel status LED for each input channel, and said digital microcontroller is further programmed with an LED status subroutine invoked by a diagnosis mechanism, for each input channel, to iteratively:

a) check a case number that indicates a predetermined status of the input channel; and

b) turn the channel status LED to a predetermined color and/or pattern based on the case number.

12. A multiple channel off-grid power inverter, comprising:

a) at least two DC power input channels;

b) an AC power output port arranged to supply AC power to an AC load;

c) for each DC power input channel, a DC-DC boost converter arranged to convert the voltage of a DC power source to a higher DC voltage suitable for inversion;

d) a DC power combiner connected to said DC-DC boost converters for combining the DC output from all DC-DC boost converters and allowing the said DC-DC boost converters to connect in parallel so that all DC currents are added together;

e) a DC-AC inverter connected to said DC power combiner and arranged to invert the DC power to AC power;

f) an internal AC powerline that allows the generated AC power to be sent to the AC load through an external AC powerline;

g) a load interface circuit connected to said DC-AC inverter and to said internal AC powerline, said load interface circuit being arranged to filter high-frequency components out of the said DC-AC inverter'"'"'s AC output;

h) a load detector connected to said internal AC powerline and external AC powerline, and arranged to detect the impedance of the connected AC load;

i) a digital microcontroller connected to said DC-DC boost converter, DC-AC inverter, load interface circuit, and load detector, said microcontroller arranged to monitor the DC boost voltage, control the DC-DC boost converter, perform maximum power point tracking (MPPT), perform DC-AC inversion, monitor AC current and voltage for generated power amount and status, perform powerline communications, check the impedance of the AC load to determine if it is within predetermined specifications, initially energize the internal and external AC powerline, continually deliver AC power to the internal and external AC powerline to allow the other power inverters also connected on the same external powerline to synchronize the AC power being produced, continually check and determine whether the AC load is too large or too small for the power generation system to handle, and turn the power off and trigger an error signal if the load is too large or too small;

j) a powerline modem connected to said microcontroller and said internal AC powerline through an interface circuitry arranged to establish a 2-way digital signal communication between the digital microcontroller and the outside world through the external AC powerline;

k) a line sensing circuit connected to said internal AC powerline and said microcontroller, and arranged to detect if there is AC power on the internal AC powerline prior to the startup of the inverter, and to monitor the internal AC powerline for over voltage, under voltage, over current, or under current conditions;

l) a power supply connected to said DC power combiner and arranged to supply DC power to the electronic components of said power inverter; and

m) a message system connected to said digital microcontroller and arranged to indicate the status of the off-grid power inverter and the status of each input channel.

13. The inverter of claim 12, in which said message system comprises:

a) a plurality of LEDs (light-emitting diodes); and

b) an LED driver circuit controlled by the digital microcontroller and arranged to turn the LEDs to a predetermined color and/or pattern to indicate the status of the power inverter and the status of each input channel of the power inverter.

14. The inverter of claim 12, in which said message system includes a system status LED to indicate that

a) the inverter is working;

b) the inverter is working but has warnings;

c) the inverter has errors;

d) the AC load has errors; and

e) the inverter is off.

15. The inverter of claim 12, further comprising an enclosure, the elements a) through m) being disposed in or on the enclosure.

16. A method for indicating status, comprising:

monitoring the status of a power inverter having multiple DC input channels and monitoring each of the input channels; and

actuating LEDs (light-emitting diodes) based on the monitoring,

wherein a system status LED is controlled and arranged to indicate that

a) the inverter is working;

b) the inverter is working but has warnings;

c) the inverter has errors;

d) the AC grid has errors; and

e) the inverter is off.

17. The method of claim 16, for each input channel, a channel status LED is controlled and arranged to indicate that

a) the input channel is working;

b) the input channel has low input voltage;

c) the input channel has errors;

d) the input channel has warnings; and

e) the input channel is off.