Inverter DC input terminal temperature detection method

Abstract

The invention relates to a method for detecting the temperature of a DC input terminal of an inverter, the DC input terminal of the inverter is arranged on a shell of the inverter, a circuit board is fixed in the shell, the surface of the circuit board is parallel to the arrangement end face of the DC input terminal, at least one temperature measurement sensing assembly is fixed on the circuit board, and the temperature measurement sensing assembly is used for measuring the temperature of the DC input terminal of the inverter. Each temperature measurement sensing assembly is provided with an effective view field, each DC input terminal is covered by at least one effective view field, each temperature measurement sensing assembly senses temperature changes in the effective view field to form electric signals, the electric signals are sent to the processor to be processed and analyzed, and temperature detection results are fed back. According to the invention, the installation difficulty of the temperature measurement structure can be reduced, the material cost and the labor cost are reduced, and the accuracy of terminal temperature detection can be improved.

Description

Technical Field

[0001] The present invention relates to the technical field of inverter safety monitoring, and in particular to a method for detecting the temperature of a DC input terminal of an inverter. Background Art

[0002] The inverter may generally include a DC side input terminal and an AC side output terminal. The DC side input terminal can transmit the current generated by the photovoltaic cell assembly or other green energy power generation assembly to the inside of the inverter through a reliable electrical connection, thereby realizing current inversion, so that the electric energy can enter the end user or be incorporated into the power grid. As an important component of the inverter, the DC side input terminal usually has a large power. Therefore, if there are problems such as aging of the terminal connector / poor contact of the wiring harness, it will cause overcurrent / short circuit heating, and the temperature generated at the DC side input terminal will rise rapidly. When the temperature is too high, it may be damaged, thereby damaging the inverter. In view of this, a temperature detection unit will be designed for the DC side input terminal for temperature detection. However, the current temperature detection of the DC side input terminal is to directly set the temperature measurement link on the terminal board, which is troublesome to install and the wiring is relatively complicated, resulting in an increase in material and labor costs, and low assembly efficiency. In addition, the current temperature measurement setting structure is not sensitive enough to the temperature change of the terminal, resulting in poor real-time detection. Summary of the invention

[0003] A main purpose of the present invention is to overcome at least one of the above-mentioned defects, and to provide a method for detecting the temperature of the DC input terminal of an inverter, which can reduce the installation difficulty of the temperature measurement structure, thereby reducing material costs and labor costs, and at the same time can improve the accuracy of terminal temperature detection.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: The present invention provides a method for detecting the temperature of a DC input terminal of an inverter, wherein the DC input terminal of the inverter is arranged on a housing of the inverter, wherein a circuit board is fixed in the housing, the surface of the circuit board is parallel to the end surface of the DC input terminal, at least one temperature measuring sensor component is fixed on the circuit board, each temperature measuring sensor component has an effective field of view, and each DC input terminal is covered by at least one effective field of view; Among them, each temperature sensing component senses the temperature change within its effective field of view to form an electrical signal, and sends the electrical signal to the processor for processing and analysis, and feeds back the temperature detection result.

[0005] According to one embodiment of the present invention, if a certain DC input terminal covers an effective field of view of a temperature sensing component, the electrical signal output by the temperature sensing component is used as a temperature feedback signal of the DC input terminal.

[0006] According to one embodiment of the present invention, if a DC input terminal is within the effective field of view of a temperature measuring sensor component and does not cover the effective field of view of the temperature measuring sensor component, the thermal radiation generated by the DC input terminal is exported to the surface of the temperature measuring sensor component through a thermal conductive optical fiber.

[0007] According to one embodiment of the present invention, the heat-conducting optical fiber is a mid-infrared hollow-core optical fiber.

[0008] According to one embodiment of the present invention, if a DC input terminal is within the effective field of view of a temperature measuring sensor component and does not cover the effective field of view of the temperature measuring sensor component, the heat generated by the DC input terminal is reflected by a heat radiation plate with a heat reflection effect to cover the effective field of view of the temperature measuring sensor component, and the electrical signal output by the temperature measuring sensor component is used as the temperature feedback signal of the DC input terminal.

[0009] According to one embodiment of the present invention, the heat radiation plate is disposed on the inner side of the shell, and a side thereof facing the temperature sensing component is covered with a coating made of aluminum or gold.

[0010] According to one embodiment of the present invention, the reflection angle of the heat radiation plate is adjusted so that the infrared waves emitted by at least one DC input terminal are reflected into the effective field of view of the temperature measuring sensor component, and the reflected infrared waves cover the effective field of view of the temperature measuring sensor component.

[0011] According to one embodiment of the present invention, each temperature sensing assembly includes at least one temperature sensing sensor, and the at least one temperature sensing sensor is arranged in an array so that the DC input terminal to be detected covers the effective field of view of the temperature sensing assembly.

[0012] According to one embodiment of the present invention, each temperature sensing assembly includes at least one temperature sensor, and the temperature sensor is a thermopile infrared sensor, a PTC thermistor, an NTC thermistor or a digital temperature measuring device.

[0013] Compared with the prior art, the advantages and beneficial effects of the inverter DC input terminal temperature detection method of the patent application of the present invention are: In this application, the temperature sensor component is directly soldered on the circuit board, and the collected signal is sent to the processor for temperature feedback through the wiring on the circuit board or the external wiring harness. In this way, the layout of the temperature sensor component can be completed at the same time as the installation of the circuit board is completed, which can effectively reduce the investment in material and labor costs.

[0014] Furthermore, by optimizing the arrangement of the temperature sensing components, the present application can more accurately capture the temperature changes of the DC input terminals, better reflect the temperature changes, and effectively improve the accuracy of terminal temperature detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Hereinafter, some specific embodiments of the present invention will be described in detail in an exemplary and non-limiting manner with reference to the accompanying drawings. The same reference numerals in the accompanying drawings indicate the same or similar components or parts. It should be understood by those skilled in the art that these drawings are not necessarily drawn to scale. In the accompanying drawings: Figure 1 is a structural schematic diagram of detecting the temperature of the DC input terminal of the inverter according to an embodiment of the present invention; Figure 2 1 is a schematic diagram of the relative positions of the effective field of view of the temperature measuring sensor component and the DC input terminal in the inverter DC input terminal temperature detection method according to an embodiment of the present invention, wherein the DC input terminal covers the effective field of view of the temperature measuring sensor component; Figure 3 is a schematic diagram of the relative positions of the effective field of view of the temperature measuring sensor component and the DC input terminal in a method for detecting the temperature of the inverter DC input terminal according to another embodiment of the present invention, wherein the DC input terminal does not cover the effective field of view of the temperature measuring sensor component; Figure 4 is a fitting curve of the effective field of view ratio and the absorbed energy ratio of the infrared thermopile sensor according to one embodiment of the present invention; Figure 5 is a schematic diagram of the relative positions of the effective field of view of the temperature measuring sensor component and the DC input terminal in the inverter DC input terminal temperature detection method according to another embodiment of the present invention, wherein the heat radiation generated by the DC input terminal is guided to the surface of the temperature measuring sensor component through a heat conducting optical fiber; Figure 6 The present invention is a schematic diagram of the relative positions of the effective field of view of a temperature measuring sensor component and a DC input terminal in a method for detecting the temperature of an inverter DC input terminal according to another embodiment of the present invention, wherein the heat radiation generated by the DC input terminal is reflected to the surface of the temperature measuring sensor component by a heat radiation plate. DETAILED DESCRIPTION

[0016] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0017] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0018] This embodiment describes a method for detecting the temperature of a DC input terminal 3 of an inverter, wherein the DC input terminal 3 of the inverter is arranged on a housing 1 of the inverter, wherein a circuit board 2 is fixed in the housing 1, the surface of the circuit board 2 is parallel to the end surface of the DC input terminal 3, and at least one temperature measuring sensor component 4 is fixed on the circuit board 2, each temperature measuring sensor component 4 has an effective field of view 41, and each DC input terminal 3 is covered by at least one effective field of view 41; Each temperature sensing component 4 senses the temperature change within its effective field of view 41 to form an electrical signal, and sends the electrical signal to the processor for processing and analysis, and feeds back the temperature detection result.

[0019] Each temperature sensing component 4 in this embodiment includes at least one temperature sensor, and the temperature sensor is a thermopile infrared sensor, so that the temperature detection method of the inverter DC input terminal 3 can have a wide temperature measurement range, and can measure a wide temperature range from low temperature to high temperature, and the measurable range is -20°C to 300°C. Moreover, in the temperature detection method of the inverter DC input terminal 3 of this embodiment, the temperature sensing component 4 does not need to be in direct contact with the DC input terminal 3 as the measurement object, and will not interfere with the measured object, and can also avoid being contaminated or damaged.

[0020] In addition, a plurality of temperature measuring sensors arranged in an array may be used to form a temperature measuring sensor assembly 4 , thereby completing a more comprehensive and detailed detection of the DC input terminal 3 .

[0021] The temperature feedback signal is regulated according to the relationship between the DC input terminal 3 and the effective field of view 41 of the temperature sensing component 4 .

[0022] like Figure 2 As shown, a certain DC input terminal 3 covers an effective field of view 41 of a temperature sensing component 4, and the electrical signal output by the temperature sensing component 4 is used as the temperature feedback signal of the DC input terminal 3. The temperature sensing component 4 completes a comprehensive detection of the DC input terminal 3, and the obtained temperature feedback signal is basically not affected by the distance between the circuit board 2 and the housing 1.

[0023] like Figure 3As shown, if a DC input terminal 3 is within the effective field of view 41 of a temperature sensing component 4 and does not cover the effective field of view 41 of the temperature sensing component 4, in this case, temperature detection is affected by the detection distance, ambient temperature and position spacing, because single-point temperature measurement is infrared thermal radiation of the object being measured + average temperature of the field of view + air attenuation = temperature output by the temperature sensor, and changes in one of these factors will result in different results.

[0024] like Figure 4 As shown, it is a fitting curve of the effective field of view 41 of the infrared thermopile sensor and the ratio of absorbed energy (under constant temperature and humidity conditions, air attenuation is not considered). As shown in the curve, when the object to be measured occupies 50% of the effective field of view 41, the ratio of its infrared thermal radiation to absorbed energy is only 0.4, so a new method is needed to overcome this problem.

[0025] like Figure 5 As shown, in one embodiment, the heat radiation generated by the DC input terminal 3 is guided to the surface of the temperature sensing component 4 through the heat conducting optical fiber 5, and the heat conducting optical fiber 5 is a mid-infrared hollow core optical fiber. The mid-infrared hollow core optical fiber prepared with the intrinsic characteristic of low material absorption has an excellent effect, and as a transmission medium, the heat radiation in the infrared band is guided to the effective field of view 41 of the infrared thermopile sensor, and directly covers the market area of ​​the temperature sensing component 4, thereby increasing the coverage area ratio.

[0026] like Figure 6 As shown, in another embodiment, if a DC input terminal 3 is within the effective field of view 41 of a temperature measuring sensor component 4 and does not cover the effective field of view 41 of the temperature measuring sensor component 4, the heat generated by the DC input terminal 3 is reflected by a heat radiation plate 6 with a heat reflection effect to cover the effective field of view 41 of the temperature measuring sensor component 4, and the electrical signal output by the temperature measuring sensor component 4 is used as the temperature feedback signal of the DC input terminal 3, and the heat radiation plate 6 is arranged on the inner side of the shell 1, and the side facing the temperature measuring sensor component 4 is covered with a coating made of aluminum or gold.

[0027] Furthermore, by adjusting the reflection angle of the heat radiation plate 6 , the infrared waves emitted by at least one DC input terminal 3 can be reflected into the effective field of view 41 of the temperature measuring sensor component 4 , and the reflected infrared waves cover the effective field of view 41 of the temperature measuring sensor component 4 .

[0028] In addition, the temperature sensors in each temperature sensing assembly 4 may also be PTC thermistors, NTC thermistors or digital temperature measuring devices, which may be selected based on specific requirements and will not be described in detail here.

[0029] In summary, the present application directly welds the temperature sensing component 4 on the circuit board 2, and sends the collected signal to the processor for temperature feedback through the wiring or external wiring harness on the circuit board 2, so that the layout of the temperature sensing component 4 can be completed while the circuit board 2 is installed, which can effectively reduce the investment in material costs and labor costs. By optimizing the layout of the temperature sensing component 4, the present application can more accurately capture the temperature changes of the DC input terminal 3, better reflect the temperature changes, and effectively improve the accuracy of terminal temperature detection.

[0030] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable people familiar with this technology to understand the contents of the present invention and implement them accordingly. They cannot be used to limit the protection scope of the present invention. Any equivalent changes or modifications made according to the spirit of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for detecting the temperature of a DC input terminal of an inverter, wherein the DC input terminal of the inverter is arranged on a housing of the inverter, and wherein: A circuit board is fixed in the housing, the surface of the circuit board is parallel to the end surface of the DC input terminal, at least one temperature sensing component is fixed on the circuit board, each temperature sensing component has an effective field of view, and each DC input terminal is covered by at least one effective field of view; Among them, each temperature sensing component senses the temperature change within its effective field of view to form an electrical signal, and sends the electrical signal to the processor for processing and analysis, and feeds back the temperature detection result.

2. The method for detecting the temperature of the inverter DC input terminal according to claim 1, characterized in that: If a certain DC input terminal covers the effective field of view of a temperature sensing component, the electrical signal output by the temperature sensing component is used as the temperature feedback signal of the DC input terminal.

3. The method for detecting the temperature of the inverter DC input terminal according to claim 1, characterized in that: If a DC input terminal is within the effective field of view of a temperature sensing component and does not cover the effective field of view of the temperature sensing component, the thermal radiation generated by the DC input terminal is guided to the surface of the temperature sensing component through a thermally conductive optical fiber.

4. The method for detecting the temperature of the inverter DC input terminal according to claim 3, characterized in that: The heat-conducting optical fiber is a mid-infrared hollow optical fiber.

5. The method for detecting the temperature of the inverter DC input terminal according to claim 1, characterized in that: If a DC input terminal is within the effective field of view of a temperature measuring sensor component and does not cover the effective field of view of the temperature measuring sensor component, the heat generated by the DC input terminal is reflected by a heat radiation plate with heat reflection function to cover the effective field of view of the temperature measuring sensor component, and the electrical signal output by the temperature measuring sensor component is used as the temperature feedback signal of the DC input terminal.

6. The method for detecting the temperature of the inverter DC input terminal according to claim 5, characterized in that: The heat radiation plate is arranged on the inner side of the shell, and a coating made of aluminum or gold is coated on a side facing the temperature sensing component.

7. The method for detecting the temperature of the inverter DC input terminal according to claim 5 or 6, characterized in that: The reflection angle of the heat radiation plate is adjusted so that the infrared waves emitted by at least one DC input terminal are reflected into the effective field of view of the temperature measuring sensor component, and the reflected infrared waves cover the effective field of view of the temperature measuring sensor component.

8. The method for detecting the temperature of the inverter DC input terminal according to claim 1, characterized in that: Each temperature sensing assembly includes at least one temperature sensing sensor, and the at least one temperature sensing sensor is arranged in an array so that the DC input terminal to be detected covers the effective field of view of the temperature sensing assembly.

9. The method for detecting the temperature of the inverter DC input terminal according to claim 1, characterized in that: Each temperature sensing assembly includes at least one temperature sensor, which is a thermopile infrared sensor, a PTC thermistor, an NTC thermistor or a digital temperature measuring device.

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