WO2020259175A1

WO2020259175A1 - Photovoltaic cell assembly having embedded photovoltaic bypass switch

Info

Publication number: WO2020259175A1
Application number: PCT/CN2020/092205
Authority: WO
Inventors: 王露; 陈隆章; 刘韬; 黄贵亮; 张真荣; 马红强; 刘丹; 陈昆
Original assignee: 重庆西南集成电路设计有限责任公司
Priority date: 2019-06-26
Filing date: 2020-05-26
Publication date: 2020-12-30
Also published as: CN110265488B; CN110265488A

Abstract

Disclosed in the present invention is a photovoltaic cell assembly having an embedded photovoltaic bypass switch, comprising a top layer of glass, an EVA adhesive film one, a photovoltaic cell pack, an EVA adhesive film two, and a bottom layer of glass. The photovoltaic cell pack comprises an embedded photovoltaic bypass switch, a photovoltaic bus bar and a photovoltaic cell string, the photovoltaic cell string consisting of a plurality of photovoltaic cells strung together. The pack is characterized in that: the embedded photovoltaic bypass switch comprises a bypass circuit, a MOS switch transistor, and a temperature measurement circuit. An anode or a cathode of the inner bypass circuit is connected in series to the MOS switch transistor, and the MOS switch transistor is controlled by the temperature measurement circuit to turn on or off. When the bypass circuit is in a safe working temperature range, the temperature measurement circuit outputs a control signal to cause the MOS switch transistor to turn on, and thus controls a bypass diode to turn on. When the bypass diode is outside the safe working temperature range, the temperature measurement circuit outputs a control signal to cause the MOS switch transistor to turn off. The present invention may used broadly for various kinds of photovoltaic cell assemblies.

Description

Photovoltaic cell module with built-in photovoltaic bypass switch

Technical field

The invention relates to a photovoltaic cell, in particular to a photovoltaic cell assembly with a built-in photovoltaic bypass switch.

Background technique

Photovoltaic bypass circuit is used on photovoltaic cell components. Its function is to protect photovoltaic cell components and prevent the hot spot effect during shading. The circuit and photovoltaic cell series and parallel can provide bypass for current and protect photovoltaic cell components from heat. The purpose of heating and being burned during spot effect. The hot spot effect means that the shaded photovoltaic cells in the photovoltaic cell series branch will be used as a load to consume the energy generated by other photovoltaic cells with light. The shaded photovoltaic cell module will heat up at this time, which is the hot spot effect, which can seriously damage the photovoltaic cell.

At present, Schottky diodes are currently used in photovoltaic bypass circuits in solar photovoltaic modules. Schottky diodes are formed by a metal-silicon bonding process on the silicon surface to form a metal-silicon junction. The forward voltage drop of the Schottky diode is limited by the material and the structure of the device. The forward voltage of the Schottky diode is about 0.4V at a current of about 10A, and the reverse leakage current is 50uA (normal temperature). It is difficult to pass the process Adjust and reduce the forward voltage.

Due to the high forward voltage drop of the existing Schottky diode, the high power consumption during the bypass protection of the hot spot effect, the heat is also very serious. In order to ensure the normal operating temperature of the Schottky diode and to ensure that heat generation does not affect the reliability of the photovoltaic cell module, it is necessary to ensure that the temperature of the photovoltaic cell module is within the long-term thermal aging temperature of the material. Due to the above reasons, some Schottky photovoltaic bypass circuits currently require a larger heat dissipation area. Therefore, the existing Schottky photovoltaic bypass circuits are installed in the photovoltaic junction box to ensure the heat dissipation effect. Install the junction box on the photovoltaic cell module. Such a scheme will affect the layout flexibility of photovoltaic modules, and lead to complex production processes and high cost of the scheme. At the same time, because Schottky diodes have low high-temperature reverse withstand voltage and large leakage, there is a risk of reverse breakdown in high-temperature reverse bias application scenarios of photovoltaic cell modules, and the quality risk is relatively high.

Summary of the invention

Aiming at the deficiencies in the prior art, the present invention proposes a photovoltaic cell assembly with a built-in photovoltaic bypass switch.

The technical scheme of the present invention is: a photovoltaic cell module with a built-in photovoltaic bypass switch, including top glass, EVA film one, photovoltaic battery pack, EVA film two, and bottom glass or photovoltaic backplane.

It is characterized in that: the photovoltaic battery pack includes a built-in photovoltaic bypass switch, a busbar and a photovoltaic cell string, and the photovoltaic cell string is composed of a plurality of photovoltaic cells in series.

The two ends of the built-in photovoltaic bypass switch are respectively welded to the first photovoltaic bus belt and the second photovoltaic bus belt, and the first photovoltaic bus belt and the second photovoltaic bus belt are respectively connected to the positive electrode and the negative electrode of the photovoltaic cell string.

The top glass, EVA adhesive film one, photovoltaic battery pack, EVA adhesive film two, and bottom glass or photovoltaic backplane are laid down from top to bottom, and laminated and packaged at high temperature.

The invention embeds the photovoltaic bypass switch in the photovoltaic cell assembly, completely replaces and optimizes the original photovoltaic bypass Schottky diode, and cancels the photovoltaic junction box, simplifies the production process, reduces the use cost, and improves Reliability and service life. It can be widely used in various photovoltaic modules, such as single-wave photovoltaic modules and double-glass photovoltaic modules.

According to the preferred solution of the photovoltaic cell module embedded with a photovoltaic bypass switch of the present invention, a hole is opened on the bottom glass, the bottom of the embedded photovoltaic bypass switch is embedded in the hole, and thermally conductive silica gel is potted in the hole , A plastic cover is set outside the hole.

According to the preferred solution of the photovoltaic cell module with built-in photovoltaic bypass switch of the present invention, the built-in photovoltaic bypass switch is composed of the body and the A terminal and K terminal pins; the A terminal and K terminal pins are respectively connected to The front and rear ends of the body; one of the pins of the A terminal and the K terminal is composed of left and right pins, and the left and right pins are electrically connected in the body. One of the A-terminal pin and the K-terminal pin is composed of connected left and right pins, which is convenient to distinguish the A-terminal K-terminal pins in practical use, and at the same time solves the packaging stress problem and improves the qualification of the chip Rate and reliability.

According to the preferred solution of the photovoltaic cell module with embedded photovoltaic bypass switch of the present invention, the thickness of the embedded photovoltaic bypass switch body is 0.6mm-1mm and the width is less than 6mm, and the body of the embedded photovoltaic bypass switch The overall length with the lead is 10-15mm, and the lead length is 2-4mm.

According to the preferred solution of the photovoltaic cell module embedded with the photovoltaic bypass switch of the present invention, a plurality of rectangular teeth are respectively provided on the left and right ends of the body, which solves the problem of packaging stress.

According to the preferred solution of the photovoltaic cell assembly with a built-in photovoltaic bypass switch of the present invention, the built-in photovoltaic bypass switch includes a bypass circuit, a MOS switch tube and a temperature detection circuit (102); the anode of the bypass circuit Or the cathode is connected in series with the MOS switch tube, the MOS switch tube is turned on and off by the temperature detection circuit (102); when the bypass circuit is within the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to make the MOS The switch tube is turned on to control the bypass circuit to be turned on; when the bypass circuit is outside the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to turn off the MOS switch tube, and then controls the bypass circuit to turn off.

According to the preferred solution of the photovoltaic cell assembly with a built-in photovoltaic bypass switch of the present invention, the bypass circuit includes a capacitor, a low-voltage clock generator, a charge pump circuit, a bandgap reference circuit, a hysteresis comparator, a drive amplifier and a power MOS tube.

The low-voltage clock generator detects the voltage across the rectifier diode and generates a clock signal to drive the charge pump circuit.

The charge pump circuit detects the voltage across the rectifier diode and amplifies it to store the charge in the capacitor.

The voltage stored on the capacitor and the reference voltage output by the bandgap reference circuit are respectively output to the hysteresis comparator for comparison; when the voltage stored on the capacitor is greater than the reference voltage output by the bandgap reference circuit, the hysteresis comparator outputs an on signal and is driven The amplifier is amplified and output to the gate of the power MOS tube to drive the power MOS tube to turn on; when the charge on the capacitor is gradually consumed by the circuit and the voltage on the capacitor gradually drops below the reference voltage output by the bandgap reference circuit, the hysteresis comparison The output of the converter turns off the signal to turn off the power MOSFET.

The gate of the MOS switch tube is connected to the temperature detection circuit (102), the drain of the MOS switch tube is connected to the source of the power MOS tube, and the source of the MOS switch tube is connected to the first photovoltaic busbar; Two photovoltaic busbar connection.

The beneficial effects of the photovoltaic cell module with built-in photovoltaic bypass switch of the present invention are: the present invention adopts a multi-chip combination and adopts a system-level packaging method, embeds the photovoltaic bypass switch into the photovoltaic cell assembly, and compares the original photovoltaic bypass switch. The special-key diode is completely replaced and optimized in performance, and the photovoltaic junction box is eliminated, which simplifies the production process, reduces the use cost, and improves the reliability and service life; the built-in photovoltaic bypass switch utilizes the low conductivity of the power MOSFET On-resistance characteristics, lower voltage drop characteristics than photovoltaic bypass Schottky diodes at the same current, and lower leakage characteristics at cut-off, solve the problem of excessive power consumption in photovoltaic bypass applications. For different photovoltaic cell modules, two in-line installation methods are designed, which can be widely used in various photovoltaic cell modules.

Description of the drawings

Fig. 1 is a schematic diagram of the structure of the photovoltaic cell module with embedded photovoltaic bypass switch according to the present invention.

2 is a schematic structural diagram of the photovoltaic cell module with built-in photovoltaic bypass switch described in Embodiment 2.

3 is a schematic diagram of the structure of the photovoltaic cell module with built-in photovoltaic bypass switch described in Embodiment 3.

Figure 4 is a schematic diagram of the circuit principle of the built-in photovoltaic bypass switch.

Fig. 5 is a schematic diagram of the connection of the photovoltaic cell module with built-in photovoltaic bypass switch according to the present invention.

Fig. 6 is a schematic diagram of the external appearance when the A terminal pin 10b of the built-in photovoltaic bypass switch is composed of left and right pins.

Fig. 7 is a left side view of Fig. 6.

FIG. 8 is a schematic diagram of the external appearance when the K terminal pin 10c of the built-in photovoltaic bypass switch is composed of left and right pins.

Detailed ways

Embodiment 1, referring to Figures 1 and 5, a photovoltaic cell module with a built-in photovoltaic bypass switch includes a top glass 11, an EVA film 12, a photovoltaic battery pack, an EVA film two 14 and a bottom glass 15; The battery pack includes a built-in photovoltaic bypass switch 10,

busbars

16a, 16b, and a photovoltaic cell string 13, which is composed of several photovoltaic cells 131 connected in series.

The two ends of the built-in photovoltaic bypass switch 10, namely, the A terminal pin and the K terminal pin are respectively welded to the first photovoltaic bus belt 16a and the second photovoltaic bus belt 16b. The first photovoltaic bus belt 16a and the second photovoltaic bus The belt 16b is respectively connected to the positive electrode 13a and the negative electrode 13b of the photovoltaic cell string 13.

The top glass 11, the first EVA film 12, the photovoltaic battery pack, the second EVA film 14 and the bottom glass 15 are laid down from top to bottom, and are laminated and packaged at a high temperature.

In a specific embodiment, referring to Figures 6 and 7, the built-in photovoltaic bypass switch is composed of a body 10a, A terminal, and

K terminal pins

10b, 10c; the body 10a is rectangular, with A terminal and K terminal leading The pins are respectively connected to the front and rear ends of the main body; and the A-end pin 10b includes two left and right pins, and the left and right pins are electrically connected in the main body to solve problems such as stress. In specific use, both the left and right pins of the A terminal pin 10b need to be welded to the first photovoltaic bus strap 16a.

Referring to FIG. 8, in a specific embodiment, the embedded photovoltaic bypass switch is composed of a body 10a, A terminal and

K terminal pins

10b, 10c; the body 10a is rectangular, and the A terminal and K terminal pins are respectively connected At the front and back ends of the body; and the K-end pin 10c includes two left and right pins, and the left and right pins are electrically connected in the body to solve problems such as stress. In specific use, the left and right two pins of the K-terminal pin 10c need to be welded to the second photovoltaic bus strap 16b.

In a specific embodiment, the thickness H of the body of the embedded photovoltaic bypass switch is 0.6mm-1mm, the width D is less than 6mm, and the overall length L of the body and the pins of the embedded photovoltaic bypass switch is 10-15mm, The lead length L1 is 2-4mm.

In a specific embodiment, a number of rectangular teeth 10a1 are provided on the left and right ends of the body 10a and respectively. At the same time, rectangular teeth are also provided on the A-end pins and K-end pins to solve problems such as stress.

In a specific embodiment, referring to FIG. 4, the embedded photovoltaic bypass switch 10 includes a bypass circuit 101, a MOS switch tube M, and a temperature detection circuit (102); the anode or cathode of the bypass circuit 101 is connected in series with the MOS switch The MOS switch tube M is turned on and off by the temperature detection circuit (102); when the bypass circuit 101 is in the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to make the MOS switch tube M When the bypass circuit 101 is outside the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to turn off the MOS switch tube M, and then controls the bypass circuit 101 to turn off Off.

The bypass circuit 101 includes a capacitor C, a low voltage clock generator 1, a charge pump circuit 2, a bandgap reference circuit 3, a hysteresis comparator 4, a driving amplifier 5 and a power MOS tube Q.

The low-voltage clock generator 1 detects the voltage across the rectifier diode and generates a clock signal to drive the charge pump circuit 2.

The charge pump circuit 2 detects and amplifies the voltage across the rectifier diode and stores the charge in the capacitor C.

The voltage stored on the capacitor C and the reference voltage output by the bandgap reference circuit 3 are respectively output to the hysteresis comparator 4 for comparison; when the voltage stored on the capacitor C is greater than the reference voltage output by the bandgap reference circuit 3, the hysteresis comparator 4 outputs Turn on the signal and output it to the gate of the power MOS transistor Q after being amplified by the drive amplifier 5, driving the power MOS transistor Q to turn on; when the charge on the capacitor C is gradually consumed by the circuit, the voltage on the capacitor C gradually drops to the band gap When the reference voltage output by the reference circuit 3 is below the reference voltage, the hysteresis comparator 4 outputs an off signal to turn off the power MOSFETQ.

The gate of the MOS switch tube M is connected to the temperature detection circuit (102), the drain of the MOS switch tube M is connected to the source of the power MOS tube Q, and the source of the MOS switch tube M is connected to the first photovoltaic bus belt 16a; the power MOS tube The drain of Q is connected to the second photovoltaic bus strap 16b.

In the present invention, a MOS switch tube is connected in series at the input end of the bypass circuit A and a temperature detector is added, and the on and off of the switch QP is controlled by the temperature detector. When the bypass circuit is within the safe operating temperature range, the temperature detection circuit outputs a control signal to turn on the switch QP, and the current flows normally from A to K of the diode circuit in Literature 1. When the current is too large, the device heats up and generates high temperature or When the external environment temperature exceeds the safe operating temperature point, the temperature detector outputs a shutdown control signal to turn off the switch QP. The current path of the diode circuit from A to K in Literature 1 is turned off, making the diode circuit stop working at high temperatures. Avoid continuous high temperature damage to itself or surrounding devices. When the temperature gradually falls within the safe operating temperature range, QP is turned on again and the circuit resumes normal operation, thereby realizing a diode circuit with thermal shutdown control function.

The second embodiment, referring to Figure 2, differs from the first embodiment in that: the photovoltaic cell module with built-in photovoltaic bypass switch includes top glass 11, EVA film 12, photovoltaic battery pack, EVA film two 14 and photovoltaic Backplane 17; The top glass 11, EVA film 12, photovoltaic battery pack, EVA film two 14 and photovoltaic backplane 17 are laid from top to bottom and laminated and packaged at high temperature.

Embodiment 3, referring to FIG. 3, is different from Embodiment 1 in that the thickness of the photovoltaic bypass switch is greater than the internal thickness of the photovoltaic cell assembly. The top glass 11, EVA film one 12, photovoltaic battery packs, EVA film two 14 and bottom glass 15 are laid from top to bottom. At the same time, holes are opened on the bottom glass 15 and the photovoltaic side is embedded. The bottom of the switch is embedded in the hole, and the hole is potted with thermally conductive silica gel 18, and a plastic cover plate 19 is set outside the hole, and the high-temperature laminated package is used.

To realize the embedded method, the external size of the embedded photovoltaic bypass switch 10 is also a very important factor, especially the thickness of the body. The embedded photovoltaic bypass switch can only be realized when the thickness requirements are met. Due to different photovoltaic module installations The methods are inconsistent. In the specific embodiment, two specific packaging types are invented to meet the requirements. Except for the inconsistent thickness, the two appearances are the same. The thickness of the photovoltaic bypass switch is 0.8mm to meet the requirements of photovoltaic cells. The internal thickness of the module is less than 0.9mm but greater than 0.8mm, and the direct embedded installation method is adopted. The thickness of the photovoltaic bypass switch is designed to be 1mm to meet the internal thickness of the photovoltaic module greater than 0.9mm but less than 1mm, due to insufficient internal thickness , The installation method of opening a hole on the top glass corresponding to the photovoltaic bypass switch and then directly embedding it is adopted to ensure the stress reliability after high temperature lamination.

The present invention uses a bypass circuit with thermal control function to replace the existing photovoltaic bypass Schottky diode used in photovoltaics. Using the characteristics of low on-resistance of power MOSFET, low reverse leakage, and good high-temperature reverse withstand voltage performance, to achieve the built-in photovoltaic bypass to reduce the forward voltage drop, the reverse leakage current, the own power loss, and the heating Reduce to achieve better performance. At the same time, the circuit can protect itself under extreme heat conditions to improve safety and reliability.

The built-in photovoltaic bypass switch circuit adopts a multi-chip combination and is realized by a system-level packaging method, which can completely replace and optimize the performance of the original photovoltaic bypass Schottky diode.

Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions and modifications can be made to these embodiments without departing from the principle and purpose of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

Photovoltaic module with built-in photovoltaic bypass switch, including top glass (11), EVA film one (12), photovoltaic battery pack, EVA film two (14) and bottom glass (15) or photovoltaic backplane (17) ；

It is characterized in that: the photovoltaic cell group includes an embedded photovoltaic bypass switch (10), a busbar (16a, 16b) and a photovoltaic cell string (13), and the photovoltaic cell string (13) consists of a number of photovoltaic cells (131). ) Series composition;

The two ends of the built-in photovoltaic bypass switch (10) are respectively welded to the first photovoltaic convergence zone (16a) and the second photovoltaic convergence zone (16b), the first photovoltaic convergence zone (16a) and the second photovoltaic convergence zone ( 16b) are respectively connected to the positive electrode (13a) and the negative electrode (13b) of the photovoltaic cell string (13);

The top glass (11), EVA film one (12), photovoltaic battery pack, EVA film two (14) and bottom glass (15) or photovoltaic backplane (17) are laid down from top to bottom, and high temperature Laminated packaging.
The photovoltaic cell module with built-in photovoltaic bypass switch according to claim 1, characterized in that: the bottom glass (15) is provided with a hole, the bottom of the embedded photovoltaic bypass switch is embedded in the hole, and the hole The inner is potted with thermally conductive silica gel (18), and a plastic cover (19) is arranged outside the hole.
The photovoltaic cell assembly with a built-in photovoltaic bypass switch according to claim 1 or 2, characterized in that: the built-in photovoltaic bypass switch consists of a body (10a) and terminals A and K pins (10b, 10c) Composition; the A-end and K-end pins are respectively connected to the front and rear of the body; one of the A-end pins (10b) and K-end pins (10c) is composed of left and right pins, And the left and right pins are electrically connected in the body.
The photovoltaic cell assembly with built-in photovoltaic bypass switch according to claim 3, characterized in that: the thickness of the body of the built-in photovoltaic bypass switch is 0.6mm-1mm and the width is less than 6mm, and the built-in photovoltaic bypass switch The overall length of the body and the lead is 10-15mm, and the lead length is 2-4mm.
The photovoltaic cell assembly with built-in photovoltaic bypass switch according to claim 3, characterized in that: a plurality of rectangular teeth (10a1) are respectively provided on the left and right ends of the main body (10a).
The photovoltaic cell module with built-in photovoltaic bypass switch according to claim 1 or 2, characterized in that: the built-in photovoltaic bypass switch (10) includes a bypass circuit (101), a MOS switch tube (M) and Temperature detection circuit (102); the anode or cathode of the bypass circuit (101) is connected in series with the MOS switch tube (M), and the MOS switch tube (M) is turned on and off by the temperature detection circuit (102); When the circuit circuit (101) is within the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to turn on the MOS switch tube (M), and then controls the bypass circuit (101) to conduct; when the bypass circuit (101) ) Is outside the safe operating temperature range, the temperature detection circuit (102) outputs a control signal to turn off the MOS switch tube (M), and then controls the bypass circuit (101) to turn off;
The photovoltaic cell assembly with built-in photovoltaic bypass switch according to claim 6, characterized in that:

The bypass circuit (101) includes a capacitor (C), a low-voltage clock generator (1), a charge pump circuit (2), a bandgap reference circuit (3), a hysteresis comparator (4), a drive amplifier (5) and Power MOS tube (Q);

The low-voltage clock generator (1) detects the voltage across the rectifier diode and generates a clock signal to drive the charge pump circuit (2);

The charge pump circuit (2) detects the voltage across the rectifier diode and amplifies it, then stores the charge in the capacitor (C);

The voltage stored on the capacitor (C) and the reference voltage output by the bandgap reference circuit (3) are output to the hysteresis comparator (4) for comparison; when the voltage stored on the capacitor (C) is greater than the output of the bandgap reference circuit (3) The hysteresis comparator (4) outputs a turn-on signal, which is amplified by the drive amplifier (5) and then output to the gate of the power MOS tube (Q), driving the power MOS tube (Q) to conduct; when the capacitor (C) When the charge on) is gradually consumed by the circuit and the voltage on the capacitor (C) gradually drops below the reference voltage output by the bandgap reference circuit (3), the hysteresis comparator (4) outputs a turn-off signal to make the power MOSFET (Q) Deadline

The gate of the MOS switch (M) is connected to the temperature detection circuit (102), the drain of the MOS switch (M) is connected to the source of the power MOS transistor (Q), and the source of the MOS switch (M) is connected to the first photovoltaic The bus band (16a) is connected; the drain of the power MOS tube (Q) is connected with the second photovoltaic bus band (16b).