MASTER SLAVE ARCHITECTURE FOR DISTRIBUTED DC TO AC POWER CONVERSION

• US 20140117769A1
• Filed: 12/31/2012
• Published: 05/01/2014
• Est. Priority Date: 10/25/2012
• Status: Active Grant

• Current Assignee: mPowerSolar Inc
• Original Assignee: SunEdison Microinverter Products LLC
• Inventors: POTHARAJU, Suryanarayana, Jayaraman, Vijay Shankar
• Granted Patent: US 10,027,114 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 1/12 Parallel operation of dc generators with converters, e.g. with mercury-arc rectifier
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/26 involving maximum power point tracking control for photovoltaic sources maximum power point systems in particular G05F1/67
• 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: 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 7/49 Combination of the output voltage waveforms of a plurality of converters
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers

Abstract

A solar module device with the master circuit generates the timing signal to synchronize each of the synchronized half wave rectified DC waveform generated by each of the slave circuits to a grid AC signal or a reference AC signal to allow the DC-AC power conversion of a plurality of solar cell groups provided in a module in an on-grid application and an off-grid application.

Claims

1. A distributed power converter for a solar module comprising:

a plurality of slave circuits, each of the slave circuits comprising;

an input comprising a DC input from a solar cell group;

a preliminary boost circuit coupled to the input, the preliminary boost circuit configured to boost an input voltage from the input from the solar cell group to an intermediary voltage;

a DC boost circuit coupled to the preliminary boost circuit and configured to boost the intermediary voltage to an AC RMS peak voltage;

a rectifier circuit coupled to the DC boost circuit and configured to wave shape the DC output to a half wave rectified DC waveform and configured to reduce a diode recovery loss in the rectifier circuit; and

an output coupled to a DC bus structure;

a master circuit, the master circuit being coupled to each of the slave circuits via the DC bus structure, the master circuit being configured to generate a timing signal to synchronize each of the slave circuits to generate a synchronized half wave rectified DC waveform to output a resulting half wave rectified DC waveform having an amplitude characterized by a combination of each of the amplitudes from each of the slave circuits.

2. The device of claim 1 wherein each input comprises a first terminal and a second terminal.

3. The device of claim 1 wherein each of the preliminary boost circuits comprises an inductive storage coupled to a capacitive storage coupled within a boost circuit.

4. The device of claim 1 wherein each of the DC boost circuit comprises a phase shift full bridge boost circuit or an advanced boost circuit achieving Zero-Voltage-Switching (ZVS) or Zero-Current-Switching (ZCS) or both ZVS and ZCS.

5. The device of claim 1 wherein each of the rectifier circuits comprises a four diode bridge circuit coupled with an energy recovery circuit.

6. The device of claim 1 wherein each of the outputs comprises a pair of terminals coupled to the DC bus structure.

7. The device of claim 1 wherein the input comprises a voltage of at least four (4) volts.

8. The device of claim 1 wherein the intermediary voltage ranges from about 15 volts to 20 volts.

9. The device of claim 1 wherein the half wave rectified DC waveform has a voltage ranging from about 160 volts to 350 volts.

10. The device of claim 11 wherein each of the half wave rectified DC waveforms is characterized by a substantially similar voltage to result in aggregated current waveform, the aggregated current waveform being substantially equal to a number of currents resulting from each of the half wave rectified DC waveforms, wherein the number is equal to a number of slave circuits in the plurality of slave circuits.

11. The device of claim 1 wherein each group of solar cells comprises a slave inverter circuit such that output power is optimized from the group of the solar cells configured in a serial manner and directly coupled to the slave circuit.

12. The device of claim 11 wherein each of the slave circuits provides a galvanic isolation between a DC source derived from each group of the solar cells and a combined AC supply which is either from a grid source or a reference AC signal generated by another device.

13. The device of claim 12 wherein each of slave inverter circuits is suspended with a common signal and prevented from performing an DC to AC inversion to enhance safety when connected to the grid source (Anti-islanding).

14. The device of claim 1 wherein the distributed power converter is provided a backside of a substrate of one of the solar modules and is substantially free from a junction box or power aggregator.

15. The device of claim 1 wherein the master circuit is configured to unfold a voltage and a current waveform on the DC bus structure.

16. A solar module device with the master circuit generates the timing signal to synchronize each of the synchronized half wave rectified DC waveform generated by each of the slave circuits to a grid AC signal or a reference AC signal to allow the DC-AC power conversion of a plurality of solar cell groups provided in a module in an on-grid application and an off-grid application.

17. The device of claim 16 wherein the master circuit is configured for at least one house-keeping operation to regulate a performance of each of the slave circuits in response to a changes in an external condition on the grid AC signal when configured in the on-grid mode.

18. The device of claim 16 wherein the master circuit is configured for at least one house-keeping operation to regulate a performance of each of the slave circuits in response to a change in an external conditions on the reference AC signal when configured in the off-grid mode.

19. The device of claim 16 wherein the synchronized half-wave rectified DC waveform is converted into a AC voltage and a current waveform to feed power into a utility grid for an on-grid operation or a micro-grid for an off-grid application through a selection of an AC un-folding circuit provided per a feature of a configured application.

20. The device of claim 19 wherein the master circuit and the un-foldering circuit uses a combination of a sense circuit to monitor the grid AC signal or reference AC signal to generate a reference signal of the slave circuit to generate the synchronized half-wave rectified DC waveform to add up a power output from each cell group.

21. A method of using a distributed power converter for a solar module comprising:

generating a DC output from a solar cell group from a plurality of solar cell groups provided in a module;

receiving the DC output at an input of a preliminary boost circuit coupled to the input;

boosting, using the preliminary boost circuit, an input voltage from the input from the solar cell group to an intermediary voltage, the preliminary boost circuit coupled to a DC boost circuit;

boosting, using the DC boost circuit, the intermediary voltage to an AC RMS peak voltage, the DC boost circuit being coupled to a rectifier circuit;

wave-shaping a DC output to a half wave rectified DC waveform while reducing a diode recovery toss in the rectifier circuit;

generating a timing signal from a master circuit to synchronize the half wave rectified DC waveform and to generate the synchronized half wave rectified DC waveform; and

combining the synchronized half wave rectified DC waveform with a plurality of other synchronized half wave rectified DC waveforms to output a resulting half wave rectified DC waveform having an amplitude characterized by a combination of each amplitude from each of synchronized half wave rectified DC waveforms.