A distributed circuit for a multi-junction photovoltaic cell containing dynamic fluorescence coupling parameters

Abstract

This invention discloses a distributed circuit for a multi-junction photovoltaic cell with dynamic fluorescence coupling parameters, comprising several connected light-emitting units and dark-emitting units. Each dark-emitting unit includes a connected first dark-emitting circuit and a second dark-emitting circuit, and each light-emitting unit includes a connected first light-emitting circuit and a second light-emitting circuit. The first dark-emitting circuit is connected to the first light-emitting circuit. The second light-emitting circuit incorporates a fluorescence coupling mechanism. A multi-junction photovoltaic cell is constructed based on these connected light-emitting and dark-emitting units. The current-voltage characteristics of the multi-junction photovoltaic cell are obtained by scanning the voltage between the external connections of the multi-junction photovoltaic cell. The simulation results obtained by the multi-junction photovoltaic cell distributed circuit model with dynamic fluorescence coupling parameters proposed in this invention are closer to the measured current-voltage characteristics than those obtained by single / dual diode circuit models and multi-junction photovoltaic cell distributed models without fluorescence coupling parameters.

Description

Technical Field

[0001] This invention belongs to the field of photovoltaic cell modeling, and in particular relates to a multi-junction photovoltaic cell distributed circuit with dynamic fluorescence coupling parameters. Background Technology

[0002] The core component of a photovoltaic (PV) power generation system is the PV cell. The equivalent circuit model of a PV cell is a crucial theoretical tool for studying PV cells, PV modules, and PV power generation systems. However, current domestic PV cell circuit modeling is generally based on a single / dual diode two-dimensional equivalent circuit model. This model has the following problems: inaccuracy; inability to handle non-uniform illumination, non-uniform temperature, complex electrode patterns, and distributed cell parameters well; significant differences from the actual operating conditions of PV cells; and limited adjustable parameters, failing to flexibly reproduce the variable operating conditions of PV cells. Furthermore, existing PV cell circuit modeling generally only considers the electroluminescence effect and not the photoluminescence effect. For multi-junction PV cells, the impact of inter-junction fluorescence coupling on the overall cell performance needs to be considered, and the fluorescence coupling parameters are often dynamic. Therefore, proposing a distributed circuit for multi-junction PV cells with dynamic fluorescence coupling parameters is of great significance. Summary of the Invention

[0003] The purpose of this invention is to provide a distributed circuit for multi-junction photovoltaic cells with dynamic fluorescence coupling parameters. This circuit incorporates the dynamic fluorescence coupling effect mechanism into a three-dimensional distributed circuit model, simultaneously considering both electroluminescence and photoluminescence effects, thereby obtaining a more accurate circuit model that more closely approximates the actual situation of multi-junction photovoltaic cells. This addresses the problems existing in the prior art.

[0004] To achieve the above objectives, the present invention provides a multi-junction photovoltaic cell distributed circuit with dynamic fluorescence coupling parameters, comprising several connected light region units and dark region units;

[0005] The dark area unit includes a first dark area circuit and a second dark area circuit connected together; the light area unit includes a first light area circuit and a second light area circuit connected together; the first dark area circuit is connected to the first light area circuit; the second light area circuit incorporates a fluorescence coupling effect mechanism.

[0006] A multi-junction photovoltaic cell is constructed based on several connected light-area units and dark-area units. The voltage-current characteristics of the multi-junction photovoltaic cell are obtained by scanning the voltage between the external wires of the multi-junction photovoltaic cell.

[0007] Optionally, the first dark area circuit includes a first dark area resistor, a second dark area resistor, a third dark area resistor, a fourth dark area resistor, a fifth dark area resistor, a sixth dark area resistor, and a seventh dark area resistor connected to each other; the first dark area resistor, the second dark area resistor, the third dark area resistor, and the fourth dark area resistor are the surface resistances of the battery emitter; the fifth dark area resistor is the semiconductor-metal contact resistance; and the sixth dark area resistor and the seventh dark area resistor are metal resistors.

[0008] The first resistor in the dark zone is connected to the first north-side interconnection terminal of the dark zone unit; the second resistor in the dark zone is connected to the first south-side interconnection terminal of the dark zone unit; the third resistor in the dark zone is connected to the first west-side interconnection terminal of the dark zone unit; the fourth resistor in the dark zone is connected to the first east-side interconnection terminal of the dark zone unit; the fifth resistor in the dark zone is connected to the center terminal of the dark zone unit; the sixth resistor in the dark zone is connected to the second west-side interconnection terminal of the dark zone unit; and the seventh resistor in the dark zone is connected to the second east-side interconnection terminal of the dark zone unit.

[0009] Optionally, the second dark area circuit is connected to the common terminal cen of the dark area unit;

[0010] The second dark zone circuit includes a dark zone eighth resistor, a dark zone ninth resistor, a dark zone tenth resistor, and a dark zone eleventh resistor;

[0011] The eighth, ninth, and tenth resistors in the dark region are all parallel losses of each junction cell, and the junction cells constitute a multi-junction photovoltaic cell.

[0012] The eleventh resistor in the dark region represents the series loss of each junction cell.

[0013] Optionally, the second dark area circuit further includes a first QNR diode, a second QNR diode, a third QNR diode, a first SCR diode, a second SCR diode, and a third SCR diode;

[0014] The first QNR diode, the second QNR diode, and the third QNR diode are used to represent carrier recombination in the neutral region of the junction cell;

[0015] The first SCR diode, the second SCR diode, and the third SCR diode are used to represent carrier recombination in the depletion region of each junction cell.

[0016] Optionally, the second dark zone circuit further includes a third voltage source, a fifth voltage source, and a sixth voltage source, wherein the third voltage source, the fifth voltage source, and the sixth voltage source are used to test the total composite current of each junction cell.

[0017] Optionally, the first optical zone circuit includes a first optical zone resistor, a second optical zone resistor, a third optical zone resistor, and a fourth optical zone resistor that are interconnected; the first optical zone resistor, the second optical zone resistor, the third optical zone resistor, and the fourth optical zone resistor are all surface resistances of the battery emitter.

[0018] The first resistor of the optical zone is connected to the north interconnect terminal of the optical zone unit; the second resistor of the optical zone is connected to the south interconnect terminal of the optical zone unit; the third resistor of the optical zone is connected to the west interconnect terminal of the optical zone unit; and the fourth resistor of the optical zone is connected to the east interconnect terminal of the optical zone unit.

[0019] Optionally, the second optical zone circuit is connected to the common terminal cen of the optical zone unit;

[0020] The second optical zone circuit includes a fifth optical zone resistor, a sixth optical zone resistor, a seventh optical zone resistor, and an eighth optical zone resistor;

[0021] The fifth resistor, the sixth resistor in the optical region, and the seventh resistor in the optical region are all parallel losses of each junction cell;

[0022] The eighth resistor in the optical region represents the series loss of each junction cell.

[0023] Optionally, the second optical area circuit further includes a first voltage source, a second voltage source, a fourth voltage source, and a seventh voltage source;

[0024] The first voltage source, the second voltage source, and the fourth voltage source are used to test the total composite current of each junction cell; the seventh voltage source is used to test the total photocurrent of the mid-junction cell.

[0025] Optionally, the second optical zone circuit further includes a fourth QNR diode, a fifth QNR diode, a sixth QNR diode, a fourth SCR diode, a fifth SCR diode, and a sixth SCR diode;

[0026] The fourth, fifth, and sixth QNR diodes are used to represent carrier recombination in the neutral region of each junction cell;

[0027] The fourth, fifth, and sixth SCR diodes are used to represent carrier recombination in the depletion region of each junction cell.

[0028] Optionally, the second optical region circuit further includes a first fluorescence coupling current, a second fluorescence coupling current, a third fluorescence coupling current, and a fourth fluorescence coupling current;

[0029] The first fluorescence coupling current is the fluorescence coupling current generated in the middle junction cell by the electroluminescence effect of the upper junction cell;

[0030] The second fluorescence coupling current is the fluorescence coupling current generated in the lower junction cell by the electroluminescence effect of the middle junction cell;

[0031] The third fluorescence coupling current is the fluorescence coupling current generated in the middle junction cell by the upper junction cell due to the photoluminescence effect;

[0032] The fourth fluorescence coupling current is the fluorescence coupling current generated in the lower junction cell by the photoluminescence effect of the middle junction cell.

[0033] The technical effects of this invention are as follows:

[0034] The simulation results obtained by the multi-junction photovoltaic cell distributed circuit model with dynamic fluorescence coupling parameters proposed in this invention are closer to the measured current-voltage characteristics than those obtained by the single / double diode circuit model and the multi-junction photovoltaic cell distributed battery model without fluorescence coupling parameters. Attached Figure Description

[0035] The accompanying drawings, which form part of this application, are used to provide a further understanding of this application. The illustrative embodiments and descriptions of this application are used to explain this application and do not constitute an undue limitation of this application. In the drawings:

[0036] Figure 1 This is a schematic diagram of the dark area unit structure in an embodiment of the present invention;

[0037] Wherein: R1 - first dark zone resistor, R2 - second dark zone resistor, R3 - third dark zone resistor, R4 - fourth resistor, R5 - fifth dark zone resistor, R6 - sixth dark zone resistor, R7 - seventh dark zone resistor, R8 - eighth dark zone resistor, R9 - ninth dark zone resistor, R10 - tenth dark zone resistor, R11 - eleventh dark zone resistor, QNR1 - first QNR diode, QNR2 - second QNR diode, QNR3 - third QNR diode, SCR1 - first SCR diode, SCR2 - second SCR diode, SCR3 - third SCR diode, V3 - third voltage source, V5 - fifth voltage source, V6 - sixth voltage source;

[0038] Figure 2 This is a schematic diagram of the optical region unit structure in an embodiment of the present invention;

[0039] Wherein: R12 - first resistor in the optical region, R13 - second resistor in the optical region, R14 - third resistor in the optical region, R15 - fourth resistor in the optical region, R16 - fifth resistor in the optical region, R17 - sixth resistor in the optical region, R18 - seventh resistor in the optical region, R19 - eighth resistor in the optical region, V1 - first voltage source, V2 - second voltage source, V4 - fourth voltage source, V7 - seventh voltage source, QNR4 - fourth QNR diode, QNR5 - fifth QNR diode, QNR6 - sixth QNR diode, SCR4 - fourth SCR diode, SCR5 - fifth SCR diode, SCR6 - sixth SCR diode, B11 - first fluorescent coupling current, B12 - second fluorescent coupling current, B13 - third fluorescent coupling current, B14 - fourth fluorescent coupling current, I3 - third photogenerated current, I4 - fourth photogenerated current, I7 - seventh photogenerated current;

[0040] Figure 3 This is a schematic diagram of the dark area unit circuit symbol in an embodiment of the present invention;

[0041] Figure 4 This is a schematic diagram of the optical zone unit circuit symbol in an embodiment of the present invention;

[0042] Figure 5 This is a schematic diagram of the overall circuit connection in an embodiment of the present invention;

[0043] Figure 6 This is a schematic diagram of the overall circuit connection test in an embodiment of the present invention. Detailed Implementation

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Example 1

[0046] like Figure 1-6 As shown, this embodiment provides a multi-junction photovoltaic cell distributed circuit with dynamic fluorescence coupling parameters, comprising several small units. These small units are divided into two categories: dark area units and light area units. The dark area units are those photovoltaic cells that are shaded by surface electrodes or grid lines, accounting for a small portion of all units; the light area units are those photovoltaic cells that are not shaded and receive normal light, accounting for the vast majority of all units.

[0047] Figure 1This is the internal structure of the dark zone cell, where QNR diodes represent neutral region recombination of each junction cell, and SCR diodes represent depletion region recombination of each junction cell. Resistors R8, R9, and R10 in the dark zone represent parallel losses of each junction cell, and R11 in the dark zone represents series losses. Voltage sources V5, V6, and V3 are used for testing. Resistors R1, R2, R3, and R4 in the dark zone are the emitter surface resistance of the cell; R5 in the dark zone is the semiconductor-metal contact resistance; and R6 and R7 in the dark zone are metal resistors.

[0048] It is feasible that the QNR diodes in the dark area include a first QNR diode QNR1, a second QNR diode QNR2, and a third QNR diode QNR3, and the SCR diodes include a first SCR diode SCR1, a second SCR diode SCR2, and a third SCR diode SCR3.

[0049] Figure 2 This describes the internal structure of the optical region unit. The third photocurrent I3, the fourth photocurrent I4, and the seventh photocurrent I7 are the photocurrents generated by each junction cell due to external illumination. The fifth resistor R16, the sixth resistor R17, and the seventh resistor R18 in the optical region represent the parallel losses of each junction cell. The eighth resistor R19 in the optical region represents the series losses. The QNR diode represents the recombination in the neutral region of each junction cell, and the SCR diode represents the recombination in the depletion region of each junction cell. The first voltage source V1, the second voltage source V2, the fourth voltage source V4, and the seventh voltage source V7 are used for debugging. The first fluorescence coupling current B11 is the fluorescence coupling current generated by the upper junction cell in the middle junction cell due to the electroluminescence effect, and the third fluorescence coupling current B13 is the fluorescence coupling current generated by the upper junction cell in the middle junction cell due to the photoluminescence effect. The fourth fluorescence coupling current B14 is the fluorescence coupling current generated in the lower junction cell by the photoluminescence effect of the middle junction cell, and the second fluorescence coupling current B12 is the fluorescence coupling current generated in the lower junction cell by the electroluminescence effect of the middle junction cell. The first resistor R12, the second resistor R13, the third resistor R14, and the fourth resistor R15 in the light region are the surface resistances of the cell emitter.

[0050] It is feasible that the QNR diodes in the optical region include a fourth QNR diode QNR4, a fifth QNR diode QNR5, and a sixth QNR diode QNR6, and the SCR diodes include a fourth SCR diode SCR4, a fifth SCR diode SCR5, and a sixth SCR diode SCR6.

[0051] Figure 3 and Figure 4 The circuit diagram symbols of the packaged dark area unit and light area unit are shown. Figure 3 In the diagram: nor is the first north-side interconnect terminal, sou is the first south-side interconnect terminal, wes is the first west-side interconnect terminal, eas is the first east-side interconnect terminal, le is the second west (north)-side interconnect terminal, ri is the second east (south)-side interconnect terminal, and ze is the common terminal of the dark area unit; Figure 4 In the diagram: nor is the north interconnect terminal, sou is the south interconnect terminal, wes is the west interconnect terminal, eas is the east interconnect terminal, and ze is the common terminal of the optical zone unit.

[0052] Implementable, the le and ri of the dark area unit are east-west or north-south grid interconnect terminals.

[0053] Figure 5 This involves interconnecting all the units to simulate a real photovoltaic cell. Due to the large number of units, Figure 5 This is a partial view of the unit connection effect diagram. The complete implementation plan (connection effect diagram) is as follows: Figure 6 As shown, all the dark area units and light area units constitute a triple-junction photovoltaic cell. The two external wires drawn out represent the positive and negative terminals of the cell. The current-voltage characteristics of the entire cell can be obtained by scanning the voltage between the positive and negative terminals. The obtained current-voltage characteristics are closer to the measured current-voltage characteristics than those obtained by simulation of the two-dimensional circuit model.

[0054] Compared to two-dimensional circuit models, three-dimensional distributed circuit models are more accurate and can flexibly and accurately handle the distributed parameters existing in both the internal and external conditions of photovoltaic cells. They more closely reflect the actual operating conditions of photovoltaic cells, such as non-uniform illumination, color difference introduced by concentrators, distributed parameters within the cell such as surface resistance or diode reverse saturation current, cell surface damage or defects, interconnection failures between cells, front contact gate shape design, and thermal degradation. Distributed circuit models can handle these issues well. On the other hand, for multi-junction photovoltaic cells, the fluorescence coupling effect between junctions must be considered to more accurately obtain the overall characteristics of the cell. The fluorescence coupling effect mainly occurs because the wide-bandgap semiconductor material in the upper junction transfers a small portion of light energy to the narrow-bandgap semiconductor material in the lower junction through photoluminescence or electroluminescence. The fluorescence coupling effect is related to the bias voltage of the wide-bandgap semiconductor material and the wavelength of the illumination. Therefore, the relevant parameters of the fluorescence coupling effect are dynamic. This embodiment incorporates the dynamic fluorescence coupling effect mechanism into the three-dimensional distributed circuit model, simultaneously considering both electroluminescence and photoluminescence effects, thereby obtaining a more accurate circuit model that more closely reflects the actual situation of multi-junction photovoltaic cells.

[0055] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A distributed circuit for a multi-junction photovoltaic cell containing dynamic fluorescence coupling parameters, characterized by, The light area unit and the dark area unit are connected; The dark area unit includes the first dark area circuit and the second dark area circuit, and the light area unit includes the first light area circuit and the second light area circuit; the first dark area circuit is connected with the first light area circuit; the second light area circuit is implanted with a fluorescent coupling effect mechanism; A multi-junction photovoltaic cell is formed based on the light area unit and the dark area unit, and a voltage-current characteristic of the multi-junction photovoltaic cell is obtained by scanning the voltage between external wires of the multi-junction photovoltaic cell; The first dark area circuit includes the first dark area resistance, the second dark area resistance, the third dark area resistance, the fourth dark area resistance, the fifth dark area resistance, the sixth dark area resistance and the seventh dark area resistance; the first dark area resistance, the second dark area resistance and the third dark area resistance are battery emitter surface resistances; the fifth dark area resistance is a semiconductor-metal contact resistance; the sixth dark area resistance and the seventh dark area resistance are metal resistances; The first dark area resistance is connected with the first north side interconnection terminal of the dark area unit; the second dark area resistance is connected with the first south side interconnection terminal of the dark area unit; the third dark area resistance is connected with the first west side interconnection terminal of the dark area unit; the fourth dark area resistance is connected with the first east side interconnection terminal of the dark area unit; the fifth dark area resistance is connected with the center terminal of the dark area unit; the sixth dark area resistance is connected with the second west side interconnection terminal of the dark area unit; and the seventh dark area resistance is connected with the second east side interconnection terminal of the dark area unit.

2. The multi-junction photovoltaic cell distribution circuit with dynamic fluorescent coupling parameters according to claim 1, wherein The second dark area circuit is connected with the common terminal cen of the dark area unit; The second dark area circuit includes the eighth dark area resistance, the ninth dark area resistance, the tenth dark area resistance and the eleventh dark area resistance; The eighth dark area resistance, the ninth dark area resistance and the tenth dark area resistance are parallel losses of the sub-cells, and the sub-cells form the multi-junction photovoltaic cell; The eleventh dark area resistance is a series loss of the sub-cells.

3. The multi-junction photovoltaic cell distribution circuit with dynamic fluorescent coupling parameters according to claim 2, wherein The second dark area circuit further includes the first QNR diode, the second QNR diode, the third QNR diode, the first SCR diode, the second SCR diode and the third SCR diode; The first QNR diode, the second QNR diode and the third QNR diode are used to represent carrier recombination in the neutral region of the sub-cells; The first SCR diode, the second SCR diode and the third SCR diode are used to represent carrier recombination in the depletion region of the sub-cells.

4. The multi-junction photovoltaic cell distribution circuit with dynamic fluorescent coupling parameters according to claim 2, wherein The second dark area circuit further includes the third voltage source, the fifth voltage source and the sixth voltage source, and the third voltage source, the fifth voltage source and the sixth voltage source are used to measure total recombination current of the sub-cells.

5. The multi-junction photovoltaic cell with dynamic fluorescent coupling parameter distribution circuit according to claim 1, wherein the first light area circuit comprises a light area first resistor, a light area second resistor, a light area third resistor and a light area fourth resistor connected to each other; the light area first resistor, the light area second resistor, the light area third resistor and the light area fourth resistor are all cell emitter surface resistors. The north side interconnection terminal of the light area unit is connected to the light area first resistor; the south side interconnection terminal of the light area unit is connected to the light area second resistor; the west side interconnection terminal of the light area unit is connected to the light area third resistor; and the east side interconnection terminal of the light area unit is connected to the light area fourth resistor.

6. The multi-junction photovoltaic cell with dynamic fluorescent coupling parameter distribution circuit according to claim 1, wherein the second light area circuit is connected to the common terminal cen of the light area unit. The second light area circuit comprises a light area fifth resistor, a light area sixth resistor, a light area seventh resistor and a light area eighth resistor. The light area fifth resistor, the light area sixth resistor and the light area seventh resistor are all parallel losses of the sub-cells. The light area eighth resistor is a series loss of the sub-cells.

7. The multi-junction photovoltaic cell with dynamic fluorescent coupling parameter distribution circuit according to claim 6, wherein the second light area circuit further comprises a first voltage source, a second voltage source, a fourth voltage source and a seventh voltage source. The first voltage source, the second voltage source and the fourth voltage source are used to measure the total recombination current of the sub-cells. The seventh voltage source is used to test the total photocurrent of the middle sub-cell.

8. The multi-junction photovoltaic cell with dynamic fluorescent coupling parameter distribution circuit according to claim 6, wherein the second light area circuit further comprises a fourth QNR diode, a fifth QNR diode, a sixth QNR diode, a fourth SCR diode, a fifth SCR diode and a sixth SCR diode. The fourth QNR diode, the fifth QNR diode and the sixth QNR diode are used to represent the carrier recombination of the neutral region of the sub-cells. The fourth SCR diode, the fifth SCR diode and the sixth SCR diode are used to represent the carrier recombination of the depletion region of the sub-cells.

9. The multi-junction photovoltaic cell with dynamic fluorescent coupling parameter distribution circuit according to claim 6, wherein the second light area circuit further comprises a first fluorescent coupling current, a second fluorescent coupling current, a third fluorescent coupling current and a fourth fluorescent coupling current. The first fluorescent coupling current is the fluorescent coupling current generated by the electroluminescence effect of the upper sub-cell on the middle sub-cell. The second fluorescent coupling current is the fluorescent coupling current generated by the electroluminescence effect of the middle sub-cell on the lower sub-cell. The third fluorescent coupling current is the fluorescent coupling current generated by the photoluminescence effect of the upper sub-cell on the middle sub-cell. The fourth fluorescent coupling current is the fluorescent coupling current generated by the photoluminescence effect of the middle sub-cell on the lower sub-cell. ​ ​ ​ ​ ​

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