US-12627155-B2 - System for balancing and converting voltage output for photovoltaic modules

US12627155B2US 12627155 B2US12627155 B2US 12627155B2US-12627155-B2

Abstract

A system for balancing and converting voltage output from photovoltaic modules includes a set of solar substrings and a power conversion circuit. The power conversion circuit includes a balancing section configured to balance voltage output from the set of solar substrings. The power conversion circuit also includes a voltage control section including: a first transformer coupled to the set of solar substrings and configured to step-up voltage from the set of solar substrings; a second transformer arranged in series to the first transformer; and an output capacitor coupled to the second transformer. The system further includes a controller configured to: drive a set of modulation signals to the balancing section and the voltage control section; alternate voltage polarities across the first transformer and the second transformer; and modify output voltage of the power conversion circuit to a target output voltage.

Inventors

Linda Stacey Irish
Sierra Rae King
Kevin Rodriguez

Assignees

OPTIVOLT LABS, INC.

Dates

Publication Date: 20260512
Application Date: 20241122

Claims (20)

1 . A system comprising a power conversion circuit, the power conversion circuit comprising: a first set of windings: arranged in parallel to a first set of solar substrings; and configured to balance voltage output from the first set of solar substrings; an adjustment transformer: coupling the first set of solar substrings to a first energy storage element; and configured to supply electrical energy from the first set of solar substrings to the first energy storage element; an inductive element coupled to the first set of windings and the adjustment transformer; a first set of switches: coupled to the first set of windings; and configured to alternate voltage polarity across the first set of windings to drive the balanced voltage output from the first set of windings to a first voltage, greater than the balanced voltage output, at the inductive element; and a second set of switches: coupled to the adjustment transformer; and configured to alternate voltage polarity across the adjustment transformer to drive the first voltage at the inductive element to a target voltage output by transferring electrical energy from the first energy storage element to the inductive element.
2 . The system of claim 1 , further comprising a controller configured to: drive a first modulation signal to the first set of switches at a first phase to induce the alternating voltage polarity across the first set of windings that drives the balanced voltage output from the first set of windings to the first voltage at the inductive element; and in response to the first voltage falling below the target voltage: drive a second modulation signal to the second set of switches at a second phase, approximating the first phase, to induce the alternating voltage polarity across the adjustment transformer that drives the first voltage at the inductive element to the target voltage.
3 . The system of claim 1 , further comprising a controller configured to: drive the first modulation signal to the first set of switches at a first phase to induce the alternating voltage polarity across the first set of windings that drives the balanced voltage output from the first set of windings to the first voltage at the inductive element; and in response to the first voltage exceeding the target voltage: drive a second modulation signal to the second set of switches at a second phase, inverse the first phase, to induce the alternating voltage polarity across the adjustment transformer that attenuates the first voltage at the inductive element to the target voltage.
4 . The system of claim 1 , wherein the inductive element comprises a complementary winding cooperating with the first set of windings to form a voltage transformer defining a step-up winding ratio that transforms the balanced voltage across the first set of windings to the first voltage across the complementary winding.
5 . The system of claim 1 , wherein the inductive element comprises a voltage transformer comprising: an input winding coupled to the first set of windings; and an output winding: coupled to the adjustment transformer; and cooperating with the input winding to define a step-up winding ratio that transforms the balanced voltage output across the first set of windings to the first voltage across the output winding.
6 . The system of claim 1 : further comprising: the first energy storage element coupled to an output side of the adjustment transformer; and a second energy storage element coupled to an input side of the adjustment transformer; and wherein the power conversion circuit further comprises a bidirectional converter: coupling the first set of solar substrings to the adjustment transformer; and configured to supply electrical energy from the first set of solar substrings to the second energy storage element.
7 . The system of claim 6 , further comprising a controller configured to, in response to the first voltage deviating from the target voltage, drive a modulation signal to the second set of switches that induces an alternating voltage polarity across the adjustment transformer to: transfer electrical energy stored within the second energy storage element to the first energy storage element; and transfer electrical energy storage stored within the first energy storage element to the inductive element.
8 . The system of claim 1 , further comprising a controller configured to, in response to the first voltage falling below the target voltage, alternate operation of the power conversion circuit between a recharge state and a delivery state by: driving a first modulation signal to the first set of switches to induce a first alternating voltage polarity across the inductive element; and driving a second modulation signal to the second set of switches to induce a second alternating voltage polarity across the adjustment transformer, the second alternating voltage polarity in phase with the first alternating voltage polarity across the inductive element.
9 . The system of claim 8 : further comprising: the first energy storage element coupled to an output side of the adjustment transformer; and a second energy storage element coupled to an input side of the adjustment transformer; and wherein the adjustment transformer is configured to: in the recharge state: transfer electrical energy from the inductive element to the first energy storage element; and transfer electrical energy from the second energy storage element to the first energy storage element; and in the delivery state: transfer electrical energy stored in the first energy storage element to the inductive element; and transfer electrical energy from the first set of solar substrings to the second energy storage element.
10 . The system of claim 1 , further comprising a controller configured to, in response to the first voltage exceeding the target voltage, alternate operation of the power conversion circuit between a recharge state and a delivery state by: driving a first modulation signal to the first set of switches to induce a first alternating voltage polarity across the inductive element; and driving a second modulation signal to the second set of switches to induce a second alternating voltage polarity across the adjustment transformer, the second alternating voltage polarity out of phase with the first alternating voltage polarity across the inductive element.
11 . The system of claim 10 : further comprising: the first energy storage element coupled to an output side of the adjustment transformer; and a second energy storage element coupled to an input side of the adjustment transformer; and wherein the adjustment transformer is configured to in the recharge state: transfer electrical energy from the inductive element to the first energy storage element; and transfer electrical energy from the second energy storage element to the first set of solar substrings; and in the delivery state, transfer electrical energy stored in the first energy storage element to the inductive element and the second energy storage element.
12 . The system of claim 1 , wherein the first set of windings: comprises: a first winding of a first quantity of turns arranged in parallel to a first solar substring in the first set of solar substrings; and a second winding of a second quantity of turns: approximating the first quantity of turns; arranged in parallel to a second solar substring of the first set of solar substrings; and arranged in series with the first winding; and are configured to passively balance a first operating voltage output from the first solar substring and a second operating voltage output from the second solar substring across the first winding and the second winding.
13 . The system of claim 12 , wherein the first set of switches comprises: a first subset of switches coupled to the first winding; and a second subset of switches: coupled to the second winding; and cooperating with the first subset of switches to alternate voltage polarity across the first winding and the second winding based on a control signal supplied to the first set of switches from a controller.
14 . The system of claim 1 : wherein the adjustment transformer comprises: an input winding; and an output winding coupled to the first energy storage element and the inductive element; and wherein the second set of switches: couple the first set of solar substrings to the input winding of the adjustment transformer; and are configured to alternate voltage polarity across the input winding to induce an adjustment voltage across the output winding of the adjustment transformer based on a voltage output from the first set of solar substrings to the first winding of the adjustment transformer.
15 . A system comprising: a power conversion circuit comprising: a first set of windings arranged in parallel to a first set of solar substrings; an adjustment transformer: coupling the first set of solar substrings to an energy storage element; and configured to supply electrical energy from the first set of solar substrings to the energy storage element; an inductive element coupled to the first set of windings and the adjustment transformer; a first set of switches coupled to the first set of windings; and a second set of switches coupled to the adjustment transformer; and a controller configured to: drive a first modulation signal to the first set of switches to induce an alternating voltage polarity across the first set of windings that drives a voltage output from the first set of windings to a first voltage at the inductive element; and in response to the first voltage deviating from a target voltage: drive a second modulation signal to the second set of switches to induce an alternating voltage polarity across the adjustment transformer to drive the first voltage at the inductive element to the target voltage by transferring energy from the energy storage element to the inductive element.
16 . The system of claim 15 , wherein the controller is configured to: drive the first modulation signal to the first set of switches at a first phase to induce the alternating voltage polarity across the first set of windings that drives the voltage output from the first set of windings to the first voltage at the inductive element; and in response to the first voltage falling below the target voltage: drive a second modulation signal to the second set of switches at a second phase, approximating the first phase, to induce an alternating voltage polarity across the adjustment transformer to increase the first voltage at the inductive element to the target voltage.
17 . The system of claim 15 , wherein the controller is configured to: drive the first modulation signal to the first set of switches at a first phase to induce the alternating voltage polarity across the first set of windings that drives the voltage output from the first set of windings to the first voltage at the inductive element; and in response to the first voltage exceeding the target voltage: drive a second modulation signal to the second set of switches at a second phase, opposite the first phase, to induce an alternating voltage polarity across the adjustment transformer to decrease the first voltage at the inductive element to the target voltage.
18 . A power conversion circuit comprising: a first set of windings arranged in parallel to a first set of solar substrings; an adjustment transformer: coupling the first set of solar substrings to an energy storage element; and configured to supply electrical energy from the first set of solar substrings to the energy storage element; an inductive element coupled to the first set of windings and the adjustment transformer; a first set of switches: coupled to the first set of windings; and configured to alternate voltage polarity across the first set of windings to drive a voltage output from the first set of windings to a first voltage, greater than the voltage output, at the inductive element; and a second set of switches: coupled to the adjustment transformer; and configured to alternate voltage polarity across the adjustment transformer to drive the first voltage at the inductive element to a target voltage by transferring electrical energy from the energy storage element to the inductive element.
19 . The system of claim 18 , wherein the inductive element comprises a complementary winding cooperating with the first set of windings to form a voltage transformer defining a winding ratio that transforms the voltage output across the first set of windings to the first voltage across the complementary winding.
20 . The system of claim 19 , wherein the inductive element comprises a voltage transformer comprising: an input winding coupled to the first set of windings; and an output winding: coupled to the adjustment transformer; and cooperating with the input winding to define a winding ratio that transforms the voltage output across the first set of windings to the first voltage across the output winding.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. Non-Provisional application Ser. No. 18/541,636, filed on 15 Dec. 2023, which claims the benefit of U.S. Provisional Application No. 63/434,426, filed on 21 Dec. 2022, and 63/465,706, filed on 11 May 2023, each of which is incorporated in its entirety by this reference. Application Ser. No. 18/541,636 is also a continuation-in-part of U.S. Non-Provisional application Ser. No. 18/211,974, filed on 20 Jun. 2023, which is a continuation of U.S. Non-Provisional application Ser. No. 17/484,615, filed on 24 Sep. 2021, which claims the benefit of U.S. Provisional Application No. 63/083,817, filed on 25 Sep. 2020, each of which is incorporated in its entirety by this reference. This application is related to U.S. Non-Provisional application Ser. No. 18/129,321, filed on 31 Mar. 2023, and Ser. No. 18/371,209, filed on 21 Sep. 2023, each of which is incorporated in its entirety by this reference. TECHNICAL FIELD This invention relates generally to the field of photovoltaic modules and more specifically to a new and useful system for balancing and converting voltage output in the field of photovoltaic modules. BRIEF DESCRIPTION OF THE FIGURES FIG. 1 is a schematic representation of a system; FIGS. 2A and 2B are schematic representations of the system; FIGS. 3A and 3B are schematic representations of the system; FIGS. 4A and 4B are schematic representations of the system; FIG. 5 is a schematic representation of the system; FIG. 6 is a schematic representation of the system; FIG. 7 is a schematic representation of the system; and FIG. 8 is a schematic representation of the system. DESCRIPTION OF THE EMBODIMENTS The following description of embodiments of the invention is not intended to limit the invention to these embodiments but rather to enable a person skilled in the art to make and use this invention. Variations, configurations, implementations, example implementations, and examples described herein are optional and are not exclusive to the variations, configurations, implementations, example implementations, and examples they describe. The invention described herein can include any and all permutations of these variations, configurations, implementations, example implementations, and examples. 1. System As shown in FIGS. 1, 2A, and 2B, a system 100 for balancing and converting output voltage for photovoltaic modules includes: a first set of solar substrings 110; a power conversion circuit 120; and a controller 160. The power conversion circuit 120 includes a balancing section 130 including: a first set of windings 132 arranged in parallel to the first set of solar substrings 110 configured to balance voltage output across the first set of solar substrings 110; and a first set of switches 135 coupled to the first set of solar substrings 110 and the first set of windings 132 and configured to alternate voltage polarity across the first set of windings 132. The power conversion circuit 120 also includes a voltage control section 140 including: a second set of windings 142; a second transformer 145; an output capacitor 150; and a second set of switches 148. The second set of windings 142 are: arranged parallel to the first set of windings 132 to form a first transformer 144; configured to step-up voltage across the first set of windings 132; and coupled to a voltage output terminal 143. The second transformer 145 includes: a third set of windings 146 arranged in series with the second set of windings 142; and a fourth set of windings 147 arranged in parallel with the third set of windings 146. The output capacitor 150 is arranged in series with the third set of windings 146. The second set of switches 148 are: coupled to an output of the first set of solar substrings 110 and the fourth set of windings 147; and configured to alternate voltage polarity across the second transformer 145 to transfer energy to the output capacitor 150. The controller 160 is configured to, in response to a first output voltage at the voltage output terminal 143 deviating from a target output voltage, trigger a first modulation signal at the first set of switches 135 to: balance voltage output from the first set of solar substrings 110 across the first set of windings 132; and induce a first alternating voltage polarity across the first transformer 144. Additionally, the controller 160 is configured to, in response to the first output voltage deviating from the target output voltage, trigger a second modulation signal at the second set of switches 148 to: induce a second alternating voltage polarity across the second transformer 145; and transfer energy from the output capacitor 150 through the second transformer 145 and the first transformer 144 to modify the first output voltage toward the target output voltage. 2. Applications Generally, the system 100 functions: as a voltage-balancing circuit to balance voltages across a series of solar substrings within a