Temperature detection device for frequency switch and micro inverter

Abstract

The temperature detection device comprises a temperature sensor and a control unit, one end of the temperature sensor is provided with a thermosensitive probe, the other end of the temperature sensor is provided with a temperature sampling circuit, the thermosensitive probe is arranged on the frequency switch in a suspended mode, the thermosensitive probe is connected into the temperature sampling circuit, and the temperature sampling circuit is connected with the control unit. The temperature sampling circuit is used for generating a current signal according to the temperature detected by the thermistor; the control unit is electrically connected with the temperature sampling circuit, the control unit is used for collecting a current signal from the temperature sensor and converting the current signal into a data signal, and the control unit is further used for controlling connection or disconnection of the frequency switch. Direct detection of the temperature of the frequency switch is achieved, non-contact detection of the temperature of the frequency switch is achieved through the thermosensitive probe arranged in a suspended mode, and the accuracy and sensitivity of temperature detection are improved.

Description

Technical Field

[0001] The present application relates to the technical field of inverters, and in particular to a temperature detection device for a frequency switch and a micro inverter. Background Art

[0002] That is, the application field of frequency switches is very wide, such as inverters in the industrial and commercial fields, variable frequency air conditioners, washing machines, and refrigerators in the field of household appliances, high-speed railways, subways, and light rails in the field of rail transit, aircraft and ships in the field of military and aerospace, and new energy vehicles, wind power generation, inverters, etc. in the field of new energy.

[0003] That is, the frequency switch in the photovoltaic inverter is mainly divided into two parts: boost and inverter. In the inverter part, the frequency switch mainly converts the direct current of the photovoltaic panel into alternating current, which can achieve the effect of photovoltaic power generation. When the current flows through the frequency switch, it will cause heat. Different frequency switches have a maximum temperature resistance. Once the temperature resistance range of the frequency switch is exceeded, the frequency switch will be damaged. In the prior art, the current flowing through is determined by detecting the external heat sink of the frequency switch, but it cannot accurately reflect the temperature rise difference caused by the uneven current of the parallel single tube, and if the heat sink and the frequency switch are poorly crimped or poorly soldered, the temperature rise of the heat sink cannot reflect this problem. Utility Model Content

[0004] In order to overcome the above shortcomings, the purpose of the present application is to provide a temperature detection device and a micro inverter for a frequency switch, which can detect the temperature of the frequency switch in real time without contact, which is conducive to improving the accuracy and sensitivity of temperature detection.

[0005] In order to achieve the above objectives, this application adopts the following technical solutions:

[0006] A temperature detection device for a frequency switch, the temperature detection device comprising:

[0007] A temperature sensor, wherein one end of the temperature sensor has a thermistor and the other end has a temperature sampling circuit, the thermistor is suspended on the frequency switch, the thermistor is connected to the temperature sampling circuit, the thermistor is configured with a thermistor, the thermistor is connected to the temperature sampling circuit, and the temperature sampling circuit is used to generate a current signal according to the temperature detected by the thermistor;

[0008] A control unit is electrically connected to the temperature sampling circuit. The control unit is used to collect current signals from the temperature sensor and convert them into data signals, and is also used to control the connection or blocking of the frequency switch.

[0009] In one embodiment, the temperature sampling circuit includes a wiring terminal, a resistor, a thyristor and a capacitor, the wiring terminal is electrically connected to the control unit, pin No. 1 of the wiring terminal is grounded, pin No. 2 of the wiring terminal is connected in series with the resistor and the thermistor, and a thyristor and a capacitor arranged in parallel are connected between pin No. 1 and pin No. 2 of the wiring terminal.

[0010] In one embodiment, a thermistor is implanted in the thermistor probe, and the thermistor is connected to the temperature sampling circuit.

[0011] In one embodiment, the thermistor probe is tilted above the frequency switch, the angle between the axis of the thermistor probe and the axis of the frequency switch is a, and the angle a formed by the axis of the thermistor probe and the axis of the frequency switch is between 60-90°.

[0012] In one embodiment, the distance between the thermal probe and the frequency switch is d, and the distance d between the thermal probe and the frequency switch is between 30-35 mm.

[0013] In one embodiment, the control unit comprises:

[0014] Digital sensor: electrically connected to the temperature sampling circuit, used to collect current signals from the temperature sampling circuit and convert the circuit signals into digital signals;

[0015] Control board: electrically connected to the digital sensor, the control board is used to collect digital signals from the digital sensor and control the connection or blocking of the frequency switch according to the digital signals.

[0016] The present application embodiment provides a micro inverter, which includes:

[0017] A housing having a receiving space therein;

[0018] A mainboard, which is arranged in the accommodating space, and is provided with frequency switch groups arranged in parallel in an array, each of which includes a plurality of frequency switches arranged in series;

[0019] The temperature detection device for the frequency switch as described above is arranged above the frequency switch and is used to detect the temperature of the frequency switch.

[0020] In one embodiment, a mounting frame is disposed above the frequency switch in the housing, and a mounting hole is disposed on the mounting frame for the thermal probe to pass through.

[0021] In one embodiment, the thermal probes and the frequency switches are arranged in a one-to-one correspondence.

[0022] In one embodiment, the housing is filled with thermally conductive adhesive.

[0023] Beneficial Effects

[0024] In the present application, a thermistor is configured on the frequency switch, and an external temperature sampling circuit is used to detect the temperature of the frequency switch, thereby directly detecting the temperature of the frequency switch and the thermistor is suspended in the air to realize contactless detection of the temperature of the frequency switch, which is beneficial to improving the accuracy and sensitivity of the detected temperature.

[0025] In the present application, the temperature sampling circuit converts the temperature signal of the thermistor probe into a current signal, and the control unit controls the connection or blocking of the frequency switch according to the current signal. This design can detect the temperature of the frequency switch in real time and quickly control the connection or blocking of the frequency switch, thereby effectively controlling the temperature of the frequency switch, which is beneficial to extending the service life of the micro inverter. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The accompanying drawings are used to provide an understanding of the technical solution of the present disclosure and constitute a part of the specification. Together with the embodiments of the present disclosure, they are used to explain the technical solution of the present disclosure and do not constitute a limitation on the technical solution of the present disclosure. The shapes and sizes of the components in the accompanying drawings do not reflect the actual proportions and are only intended to illustrate the content of the present application.

[0027] Figure 1 A schematic diagram of the temperature device structure provided in an embodiment of the present application;

[0028] Figure 2 A side view of a temperature device provided in an embodiment of the present application;

[0029] Figure 3 A temperature sampling circuit diagram provided in an embodiment of the present application. DETAILED DESCRIPTION

[0030] The above scheme is further described below in conjunction with specific examples. It should be understood that these examples are used to illustrate the present application and are not limited to the scope of the present application. The implementation conditions adopted in the examples can be further adjusted as the conditions of the specific manufacturer, and the unspecified implementation conditions are usually the conditions in conventional experiments.

[0031] Unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present disclosure should be understood by people with ordinary skills in the field to which the present application belongs. The "first", "second" and similar words used in the embodiments of the present disclosure do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing in front of the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connecting" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. In this article, "electrical connection" includes the situation where the constituent elements are connected together through an element with some electrical function. "Elements with some electrical function" are not particularly limited as long as they can transfer electrical signals between the connected constituent elements. "Elements with some electrical function" can be, for example, electrodes or wiring, or switching elements such as transistors, or other functional elements such as resistors, inductors or capacitors. "Up", "down", "left", "right", etc. are only used to indicate relative position relationships. When the absolute position of the object being described changes, the relative position relationship may also change accordingly.

[0032] In this application, the directions or positional relationships indicated by the terms "upper", "lower", "inner", "middle", etc. are based on the directions or positional relationships shown in the drawings. These terms are mainly used to better describe the present application and its embodiments, and are not used to limit the indicated devices, elements or components to have a specific direction, or to be constructed and operated in a specific direction.

[0033] The present application discloses a temperature detection device for a frequency switch and a micro inverter. The temperature detection device includes a temperature sensor and a control unit. One end of the temperature sensor has a thermistor probe and the other end has a temperature sampling circuit. The thermistor probe is suspended on the frequency switch. The thermistor probe is connected to the temperature sampling circuit. The temperature sampling circuit is used to generate a current signal according to the temperature detected by the thermistor. The control unit is electrically connected to the temperature sampling circuit. The control unit is used to collect the current signal from the temperature sensor and convert it into a data signal, and is also used to control the connection or blocking of the frequency switch. In the present application, the thermistor probe is configured on the frequency switch, and the temperature sampling circuit is externally connected to detect the temperature of the frequency switch, so as to realize direct detection of the temperature of the frequency switch and the suspended thermistor probe realizes contactless detection of the temperature of the frequency switch, which is conducive to improving the accuracy and sensitivity of the detected temperature. The temperature sampling circuit converts the temperature signal of the thermistor probe into a current signal, and the control unit controls the connection or blocking of the frequency switch according to the current signal. Such a design can detect the temperature of the frequency switch (such as an IGBT switch) in real time, and quickly control the connection or blocking of the frequency switch, thereby effectively controlling the temperature of the frequency switch, and thus helping to extend the service life of the micro inverter. The micro inverter comprises a shell, a mainboard and a temperature detection device.

[0034] The housing has a storage space inside. Specifically, the housing includes a first housing and a second housing. The first housing and the second housing are assembled to form the storage space.

[0035] A mainboard is arranged in the accommodation space, and a plurality of frequency switches are configured on the mainboard, and the specific frequency switches are MOS switches or IGBT switches;

[0036] The temperature detection device is arranged in the accommodating space and located above the frequency switch, and is used for detecting the temperature of the frequency switch.

[0037] In this embodiment, the shell is filled with thermal conductive adhesive, which is conducive to heat dissipation of the micro inverter. Furthermore, the shell can be made of aluminum profile, which has better thermal conductivity and is convenient for conducting the heat generated by the components inside the shell to the outside for heat dissipation.

[0038] In this embodiment, a mounting frame is arranged above the frequency switch in the shell, and a mounting hole is arranged on the mounting frame for the thermistor probe to pass through. The thermistor probe is inserted into the mounting hole for fixation to avoid displacement of the thermistor probe when filling the shell with thermal conductive glue.

[0039] In this embodiment, the thermistor and the frequency switch are arranged in a one-to-one correspondence, that is, a thermistor is arranged above each frequency switch, so that the design can accurately detect the heat of a single frequency switch and perform real-time detection. In one embodiment, each thermistor is connected to a temperature sampling circuit, and in other embodiments, multiple thermistors can be arranged in parallel on a temperature sampling circuit.

[0040] Next join Figure 1-Figure 3 A temperature detection device for a frequency switch provided in an embodiment of the present application is described. The temperature detection device can detect the temperature of the frequency switch in real time without contact, which is beneficial to improving the accuracy and sensitivity of the detected temperature.

[0041] The temperature detection device includes a temperature sensor and a control unit, wherein one end of the temperature sensor has a thermistor probe 10 and the other end has a temperature sampling circuit, the thermistor probe 10 is suspended on the frequency switch 20, the thermistor probe is connected to the temperature sampling circuit, and the temperature sampling circuit is used to generate a current signal according to the temperature detected by the thermistor;

[0042] The control unit is electrically connected to the temperature sampling circuit. The control unit is used to collect current signals from the temperature sensor and convert them into data signals, and is also used to control the connection or blocking of the frequency switch.

[0043] refer to Figure 3 In this embodiment, the temperature sampling circuit includes a wiring terminal CN1, a resistor R15 (1K), a thyristor TR1 and a capacitor C15, wherein the wiring terminal CN1 is electrically connected to the control unit, pin No. 1 of the wiring terminal is grounded, pin No. 2 of the wiring terminal is connected in series with the resistor R15 (1K) and the thermistor probe, and the thyristor TR1 and the capacitor C15 arranged in parallel are connected between pin No. 1 and pin No. 2 of the wiring terminal R15 (1K).

[0044] In this embodiment, a thermistor (THERMAL1 B) is implanted in the thermistor probe, and the thermistor (THERMAL1B) is connected to the temperature sampling circuit. Specifically, the thermistor is preferably an NTC thermistor. The thermistor is located at one end of the probe thermistor probe 10 close to the frequency switch. The thermistor adopts a probe-type structure design to improve the temperature response speed.

[0045] refer to Figure 2 In this embodiment, the thermistor probe 10 is tilted above the frequency switch 20, and the angle between the axis of the thermistor probe 10 and the axis of the frequency switch is a. The angle a formed by the axis of the thermistor probe and the axis of the frequency switch is between 60-90°. This design can further reduce the space above the frequency switch and improve space utilization.

[0046] In this embodiment, the distance between the thermal probe and the frequency switch is d, and the distance d between the thermal probe and the frequency switch is between 30-35 mm.

[0047] refer to Figure 3 In this embodiment, the control unit includes a digital sensor DSP and a control board CPU, wherein the digital sensor DSP is electrically connected to a temperature sampling circuit, and is used to collect current signals from the temperature sampling circuit and convert the circuit signals into digital signals; the control board CPU is electrically connected to the digital sensor, and the control board CPU is used to collect digital signals from the digital sensor DSP, and control the connection or blocking of the frequency switch according to the digital signals.

[0048] The above embodiments are only for illustrating the technical concept and features of the present application, and their purpose is to enable people familiar with the technology to understand the content of the present application and implement it accordingly, and they cannot be used to limit the protection scope of the present application. Any equivalent transformation or modification made according to the spirit of the present application shall be included in the protection scope of the present application.

Claims

1. A temperature detection device for a frequency switch, characterized in that: include: A temperature sensor, wherein one end of the temperature sensor has a thermistor and the other end has a temperature sampling circuit, the thermistor is suspended on the frequency switch, the thermistor is connected to the temperature sampling circuit, the thermistor is configured with a thermistor, the thermistor is connected to the temperature sampling circuit, and the temperature sampling circuit is used to generate a current signal according to the temperature detected by the thermistor; A control unit is electrically connected to the temperature sampling circuit. The control unit is used to collect current signals from the temperature sensor and convert them into data signals, and is also used to control the connection or blocking of the frequency switch.

2. The temperature detection device for a frequency switch according to claim 1, characterized in that: The temperature sampling circuit comprises a wiring terminal, a resistor, a thyristor and a capacitor, and the wiring terminal is electrically connected to the control unit.

3. The temperature detection device for a frequency switch according to claim 2, characterized in that: Pin No. 1 of the wiring terminal is grounded, pin No. 2 of the wiring terminal is connected in series with a resistor and a thermistor, and a thyristor and a capacitor arranged in parallel are connected between pin No. 1 and pin No. 2 of the wiring terminal.

4. The temperature detection device for a frequency switch according to claim 1, characterized in that: The thermosensitive probe is tiltedly arranged above the frequency switch, the angle between the axis of the thermosensitive probe and the axis of the frequency switch is a, and the angle a formed by the axis of the thermosensitive probe and the axis of the frequency switch is between 60-90°.

5. The temperature detection device for a frequency switch according to claim 1, characterized in that: The distance between the thermal probe and the frequency switch is d, and the distance d between the thermal probe and the frequency switch is between 30-35 mm.

6. The temperature detection device for a frequency switch according to claim 1, characterized in that: The control unit includes: Digital sensor: electrically connected to the temperature sampling circuit, used to collect current signals from the temperature sampling circuit and convert the circuit signals into digital signals; Control board: electrically connected to the digital sensor, the control board is used to collect digital signals from the digital sensor and control the connection or blocking of the frequency switch according to the digital signals.

7. A micro inverter, characterized in that: include: A housing having a receiving space therein; A mainboard, which is arranged in the accommodating space, and is provided with frequency switch groups arranged in parallel in an array, each of which includes a plurality of frequency switches arranged in series; and A temperature detection device for a frequency switch according to any one of claims 1 to 6: arranged above the frequency switch, and used to detect the temperature of the frequency switch.

8. The micro inverter according to claim 7, characterized in that: A mounting frame is arranged above the frequency switch in the housing, and a mounting hole for the thermal probe to pass through is arranged on the mounting frame.

9. The micro inverter according to claim 7, characterized in that: The thermal sensitive probes are arranged in one-to-one correspondence with the frequency switches.

10. The micro inverter according to claim 7, characterized in that: The shell is filled with heat-conducting glue.

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