System for Use of Static Inverters in Variable Energy Generation Environments

• US 20110304215A1
• Filed: 05/31/2011
• Published: 12/15/2011
• Est. Priority Date: 06/09/2010
• Status: Active Grant

• Current Assignee: Tigo Energy, Inc
• Original Assignee: Tigo Energy, Inc
• Inventors: Avrutsky, Mordechay, Kikinis, Dan
• Granted Patent: US 8,853,886 B2
• Time in Patent Office: Days
• US Class Current: 307/82
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 2300/28 The renewable source being wind energy
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 3/46 Controlling of the sharing of output between the generators, converters, or transformers
• CPC Class Codes: H02M 1/42 Circuits or arrangements for compensating for or adjusting power factor in converters or inverters
• CPC Class Codes: H02M 7/42 Conversion of dc power input into ac power output without possibility of reversal
• 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 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y02E 10/76 Power conversion electric or electronic aspects

Abstract

A system to collect energy from generation systems such as, for example, wind farms or solar farms with widely distributed energy-generation equipment. In some cases, static inverters are used to feed the energy directly into the power grid. In some other cases, back-to-back static inverters are used create a high-voltage DC transmission line to collect power from multiple generation sites into one feed-in site.

Claims

1. A energy generation system comprising:

one or more strings of variable energy collectors;

one or more string converters as managed by a first controller to combine voltage outputs of the one or more strings of variable energy collectors into a energy output stream;

the energy output stream routed to a static inverter via a bus, the static inverter comprising;

switches for converting the electrical energy output to an alternating current; and

a transformer arrangement comprising a transformer and a balancing transformer to convert the alternating current to an alternating current with a given voltage;

the first controller or a second controller receiving measurements of voltage phase on a grid; and

the first controller or the second controller to control timing of the switches in accordance with the measurements of the voltage phase.

2. The system of claim 1, wherein said transformer arrangement outputs the alternating current with the given voltage;

3. The system of claim 2, wherein the first controller and/or the second controller can send data over a network about energy being output.

4. The system of claim 1, wherein the first controller and/or the second controller can send data to a supervisory site and/or receive data from the supervisory site.

5. The system of claim 1, wherein the transformer arrangement is configured to generate three phase alternating current.

6. The system of claim 1, wherein the transformer arrangement comprises one or more filters to transform a waveform of the alternating current with the given voltage.

7. The system of claim 5, wherein the transformer is a delta-wye-delta transformer.

8. The system of claim 1, wherein the first controller or the second controller communicates with a network such that the first controller and/or the second controller can send and receive data over the network regarding operation of the system.

9. An energy generation system comprising:

one or more variable energy collecting units producing respective direct current (DC) voltage levels;

a first controller in communication with the units to enable the DC voltage levels to be compatible on a bus;

the bus to deliver a DC compatible voltage level to a static inverter wherein the static inverter converts the DC compatible voltage level to an alternating current;

a pulse width modulation inverter to receive an alternating current output of the static inverter; and

the first controller or a second controller in communication with the static inverter and the pulse width modulation inverter to control the alternating current output from the static inverter to the pulse width modulation inverter.

10. The system of claim 9, wherein a capacitor is in electrical communication with the bus.

11. The system of claim 9, wherein a modified alternating current flow is output from the pulse width modulation inverter to a feeding point.

12. A energy generation system comprising:

one or more variable energy collecting units to produce direct current (DC);

a controller in communication with the units to maintain a desired voltage on a bus;

a bus to deliver the DC to a first static inverter wherein the first static inverter converts the DC to an alternating current; and

the alternating current delivered to a second static inverter wherein the second static inverter converts the alternating current to a high voltage direct current.

13. The system of claim 12, further comprising a filter to modify a waveform of the alternating current.

14. The system of claim 12, further comprising the controller in communication with a master static inverter receiving an output of the high voltage direct current.

15. The system of claim 12, further comprising the controller in communication with a grid.