Method for balancing circuit voltage

• US 9,407,093 B2
• Filed: 07/08/2014
• Issued: 08/02/2016
• Est. Priority Date: 08/22/2007
• Status: Active Grant

• Current Assignee: Maxout Renewables, Inc.
• Original Assignee: Maxout Renewables, Inc.
• Inventors: Cummings, Eric Bryant
• Primary Examiner(s): CAVALLARI, DANIEL J
• Application Number:
  US14/326,229
• Publication Number:
  US 20140319916A1
• Time in Patent Office: 756 Days
• US Class Current: 1/1
• CPC Class Codes: H01L 31/02021 for solar cells electrical connection means, e.g. junction boxes, specially adapted for structural association with photovoltaic modules H02S40/34
• CPC Class Codes: H02J 1/001 Hot plugging or unplugging of load or power modules to or from power distribution networks
• CPC Class Codes: H02J 1/102 being switching converters H02J1/108, H02J1/12 take precedence
• CPC Class Codes: H02J 1/106 for load balancing, symmetrisation, or sharing
• CPC Class Codes: H02J 2300/24 of photovoltaic origin
• CPC Class Codes: H02J 3/381 Dispersed generators
• CPC Class Codes: H02J 9/062 for AC powered loads
• CPC Class Codes: H02M 1/0043 Converters switched with a phase shift, i.e. interleaved non-isolated DC/DC converters H02M3/1586
• CPC Class Codes: H02M 7/493 the static converters being arranged for operation in parallel
• CPC Class Codes: H02S 40/32 comprising DC/AC inverter means associated with the PV module itself, e.g. AC modules
• CPC Class Codes: Y02B 10/70 Hybrid systems, e.g. uninterruptible or back-up power supplies integrating renewable energies
• CPC Class Codes: Y02E 10/56 Power conversion systems, e.g. maximum power point trackers
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

Various techniques are employed alone or in combination, to reduce the levelized cost of energy imposed by a power plant system. Solar energy concentrators in the form of inflated reflectors, focus light onto photovoltaic receivers. Multiple concentrators are grouped into a series-connected cluster that shares control circuitry and support structure. Individual concentrators are maintained at their maximum power point via balance controllers that control the flow of current that shunts this series connection. DC current from clusters is transmitted moderate distances to a centralized inverter. The inductance of transmission lines is maximized using an air-spaced twisted pair, enhancing the performance of boost-type three phase inverters. Cluster outputs are separate from individual inverters in massively interleaved arrays co-located at a central location. Step-up transformers convert inverter voltages to grid voltages, and small transformers provide isolation and voltage step-up only on receiver-to-receiver imbalance currents, typically <20% of the total current.

Claims

1. A method for balancing circuit voltage comprising:

receiving, at a circuit, power from a plurality of power-generating elements, the circuit being coupled to first and second devices, the first device being communicatively coupled to the second device; and

increasing, using a switch of the second device, a load on at least one of the plurality of power-generating elements such that the voltage of the circuit does not exceed an upper threshold voltage.

2. The method of claim 1, wherein the first device is an inverter and the second device is a balancer.

3. The method of claim 1, wherein the switch is a semiconductor or mechanical relay.

4. The method of claim 1, wherein the circuit includes a pair of wires that are spaced a first distance apart and are helically twisted.

5. The method of claim 4, wherein the circuit further includes an insulator disposed between the pair of wires.

6. The method of claim 4, wherein the first distance is greater than a diameter of each of the pair of wires.

7. The method of claim 6, wherein the helically twisted pair of wires is flattened.