Thin-film photovoltaic power system with integrated low-profile high-efficiency inverter
A photovoltaic device including at least one photovoltaic cell and a transformerless inverter electrically coupled to the at least one photovoltaic cell. The at least one photovoltaic cell and the transformerless inverter are integrated into a photovoltaic package.
1 . A photovoltaic device, comprising:
at least one photovoltaic cell; and
a transformerless inverter electrically coupled to the at least one photovoltaic cell,
wherein the at least one photovoltaic cell and the transformerless inverter are integrated into a photovoltaic package.
2 . The device of claim 1 , wherein the photovoltaic package comprises a low-profile laminate or non-laminate package.
3 . The device of claim 2 , wherein the low-profile package is less than 11 mm thick.
4 . The device of claim 3 , wherein the low-profile package is less than 5 mm thick.
5 . The device of claim 2 , wherein the at least one photovoltaic cell is a thin-film photovoltaic cell.
6 . The device of claim 5 , further comprising a ceramic capacitor electrically coupled to a string of the thin-film photovoltaic cells which include the at least one photovoltaic cell.
7 . The device of claim 6 , wherein the transformerless inverter comprises a transformerless buck converter.
8 . The device of claim 7 , wherein the transformerless buck converter comprises at least one of a synchronous buck converter or an asynchronous buck converter.
9 . The device of claim 7 , further comprising a controller coupled to the transformerless buck converter, the controller comprising a peak power tracker and at least one of a discontinuous conduction mode controller or a boundary conduction mode controller.
10 . The device of claim 9 , wherein the transformerless buck converter comprises at least one transistor, at least one diode, and at least one inductor for asynchronous operation; or at least two transistors and at least one inductor for synchronous operation.
11 . The device of claim 10 , wherein the at least one inductor is integrated onto a printed circuit board or at least one layer of the package.
12 . The device of claim 9 , wherein the transformerless inverter further comprises a transformerless boost converter electrically coupled to the controller.
13 . The device of claim 7 , wherein the transformerless inverter comprises a transformerless buck-boost converter.
14 . A method of operating a photovoltaic device, comprising:
providing an input power from a photovoltaic cell to a transformerless DC/DC converter;
operating the transformerless DC/DC converter in at least one of a discontinuous conduction mode or a boundary conduction mode; and
providing an output power from the transformerless DC/DC converter to an unfolder.
15 . The method of claim 14 , wherein the transformerless DC/DC converter comprises a transformerless buck converter.
16 . The method of claim 15 , wherein the step of operating comprises operating the transformerless buck converter in discontinuous conduction mode.
17 . The method of claim 16 , wherein operating the transformerless buck converter in discontinuous conduction mode comprises ending a switching period of the transformerless buck converter after an inductor current of the transformerless buck converter reaches zero.
18 . The method of claim 17 , wherein the transformerless buck converter comprises at least one transistor, at least one diode, and at least two integrated inductors.
19 . The method of claim 17 , further comprising controlling a duty cycle of the switching period in order to shape an output of the unfolder.
20 . The method of claim 15 , wherein the step of operating comprises operating the transformerless buck converter in boundary conduction mode.
21 . The method of claim 20 , wherein operating the transformerless buck converter in boundary conduction mode comprises ending a switching period of the transformerless buck converter when a current of one of the at least two integrated inductors reaches zero.
22 . The method of claim 15 , wherein the transformerless DC/DC converter further comprises a transformerless boost converter.
23 . The method of claim 22 , wherein the transformerless buck converter and the transformerless boost converter together comprise at least two transistors controlled by a controller, and wherein the transformerless buck converter and the transformerless boost converter operate in different modes.
24 . The method of claim 14 , wherein the transformerless DC/DC converter further comprises a transformerless buck-boost converter.
25 . The method of claim 14 , wherein the photovoltaic cell, the transformerless DC/DC converter, and the unfolder comprise a photovoltaic package less than 11 mm thick.
26 . A photovoltaic circuit, comprising:
at least one photovoltaic cell;
a storage capacitor electrically coupled to the at least one photovoltaic cell;
a transformerless DC/DC converter electrically coupled to the storage capacitor;
an electromagnetic interference (EMI) filter electrically coupled to the transformerless DC/DC converter;
an unfolder electrically coupled to the EMI filter; and
a controller electrically coupled to the transformerless DC/DC converter.
27 . The circuit of claim 26 , wherein the at least one photovoltaic cell, the storage capacitor, the transformerless DC/DC converter, the EMI filter, the unfolder, and the controller are integrated into a photovoltaic package.
28 . The circuit of claim 27 , wherein the photovoltaic package comprises a low-profile laminate or non-laminate package.
29 . The circuit of claim 28 , wherein the low-profile package is less than 11 mm thick.
30 . The circuit of claim 29 , wherein the low-profile package is less than 5 mm thick.
31 . The circuit of claim 27 , wherein the DC/DC converter comprises a buck converter.
32 . The circuit of claim 31 , wherein the DC/DC converter further comprises a boost converter, and wherein the DC/DC converter comprises at least two transistors.
33 . The circuit of claim 27 , wherein the DC/DC converter comprises a buck-boost converter.
34 . The circuit of claim 31 , further comprising a controller coupled to the buck converter, the controller comprising a maximum power point tracker and at least one of a discontinuous conduction mode controller or a boundary conduction mode controller.
35 . The circuit of claim 34 , wherein the controller partially comprises digital circuitry.
36 . The circuit of claim 28 , wherein the EMI filter comprises at least one inductor integrated into a printed circuit board.
37 . The circuit of claim 28 , wherein components of the transformerless DC/DC converter, the EMI filter, or the unfolder are integrated onto at least one of a printed circuit board, a flex circuit, a substrate, or back barrier of the package.