Inverter and inverter overheating protection structure

Abstract

The utility model discloses an inverter overheating protection structure, wherein the overheating protection structure, including inverter protection shell, refrigeration subassembly, heat exchanger and temperature sensor, the top of inverter protection shell is equipped with ventilation opening, and the rear portion is provided with the heat dissipation window, heat exchanger is installed in the heat dissipation window, and the heat dissipation window is provided with the bidirectional fan between heat exchanger, refrigeration subassembly includes semiconductor refrigeration piece, and the cold end of semiconductor refrigeration piece is connected with liquid cooling pump, and the hot end of semiconductor refrigeration piece is connected with the radiating plate, and the radiating plate sets up in inverter protection shell outside, liquid cooling pump is connected with heat exchanger through cooling liquid pipeline, temperature sensor sets up in inverter protection shell, and temperature sensor passes through control circuit and is electrically connected with semiconductor refrigeration piece and bidirectional fan, when temperature sensor detects that inverter temperature is too high, will control refrigeration subassembly to intervene, and sends the cold wind to inverter protection shell through heat exchanger and bidirectional fan, carries out the cooling to inverter, has reduced the probability of inverter overheating shutdown.

Description

Technical Field

[0001] This utility model belongs to the field of inverter technology, specifically an inverter and an inverter overheat protection structure. Background Technology

[0002] An inverter is a converter that transforms direct current (DC) power (from photovoltaic power generation systems, UPS, etc.) into fixed-frequency, fixed-voltage or frequency- and voltage-modulated alternating current (AC) power (typically 220V, 50Hz sine wave). It consists of an inverter bridge, control logic, and filter circuits.

[0003] The electronic components inside the inverter, such as capacitors, inductors, and PCB boards, are extremely sensitive to temperature. When the inverter temperature is too high, continuous overheating will cause the electrolyte to dry out and the magnetic core characteristics to change, resulting in a sharp decline in inverter performance. At the same time, inverter power components such as IGBTs and MOSFETs will generate heat under high loads. If the heat dissipation is poor, the junction temperature will quickly exceed the maximum allowable value, causing them to be thermally broken down and permanently burned out.

[0004] The most common and effective method for inverter overheat protection is to use mechanical or circuit structures to cut off the inverter's input current or load when the inverter temperature exceeds a threshold, thus stopping the inverter from working. For example, Chinese utility model patent CN223230873U discloses an overheat protection structure for a photovoltaic-storage inverter, including the inverter body, a temperature controller, and input wires. The temperature controller is connected in series with the input wires. The temperature controller includes an aluminum shell, a mounting base, a cover plate, a pair of terminals, a moving contact, a fixed contact, a push rod, a bimetallic strip, and a limiting plate. The moving contact on the moving contact is elastically connected to the fixed contact on the fixed contact. The moving contact and the fixed contact are each connected to the cover plate through a terminal. One end of the push rod is fixedly connected to the bimetallic strip, passes through the middle of the limiting plate, and is pulled or extended within the limiting plate. When the bimetallic strip is subjected to high temperature and suddenly jumps towards the limiting plate, it pushes the push rod out of the limiting plate, abutting the moving contact and separating the moving contact from the fixed contact. An open circuit forms in the input wire, resulting in no input power to the photovoltaic-storage inverter, causing it to stop operating. No more heat is generated. The temperature of the photovoltaic-storage inverter gradually decreases.

[0005] However, inverter overheating and power outages can also lead to economic losses and safety hazards. For example, the entire photovoltaic system may stop generating electricity and can only be manually or automatically restarted after the inverter cools down to a safe temperature. In unattended power plants or critical power supply situations, shutdowns can also pose serious safety risks. Utility Model Content

[0006] This utility model proposes an inverter and an inverter overheat protection structure, which aims to prevent the inverter temperature from getting too high and reduce the probability of the inverter overheating and shutting down.

[0007] To achieve the above objectives, the first aspect of this utility model proposes an inverter overheat protection structure, including an inverter protective shell, a cooling component, a heat exchanger, and a temperature sensor. The inverter protective housing has a ventilation opening at the top and a heat dissipation window at the rear. The heat exchanger is installed inside the heat dissipation window, and a bidirectional fan is provided between the heat dissipation window and the heat exchanger. The refrigeration component includes a thermoelectric cooler, the cold end of which is connected to a liquid cooling pump, and the hot end of which is connected to a heat sink, which is disposed outside the inverter protective housing; the liquid cooling pump is connected to a heat exchanger through a coolant pipeline. The temperature sensor is housed inside the inverter's protective casing and is connected to the semiconductor cooling chip and bidirectional fan via a control circuit.

[0008] Preferably, the liquid cooling pump is a contact type liquid cooling pump, and the bottom of the liquid cooling pump is in contact with the cold end of the semiconductor cooling chip through a heat-conducting plate.

[0009] Preferably, the heat exchanger includes an upper chamber and a lower chamber, with a vertical pipe connecting the upper chamber and the lower chamber. Fins are installed on the vertical pipe. The upper chamber is connected to the outlet of the liquid cooling pump through a liquid inlet pipe, and the lower chamber is connected to the inlet of the liquid cooling pump through a return pipe.

[0010] Preferably, the control circuit includes a comparator, the analog output of the temperature sensor is connected to the non-inverting input of the comparator, the inverting input of the comparator is connected to a reference voltage input, the output of the comparator is connected to a relay and a reversing switch through a transistor, the thermoelectric cooler is connected to a DC power supply through the relay, and the bidirectional fan is connected to a DC power supply through the reversing switch.

[0011] Preferably, a hysteresis resistor is connected in parallel between the output terminal and the non-inverting input terminal of the comparator.

[0012] Preferably, the temperature sensor is an NTC thermistor. One end of the NTC thermistor is connected to the power supply bus of the control circuit, and the other end is connected in series with a first voltage divider resistor and grounded. The voltage division point between the NTC thermistor and the first voltage divider resistor is connected to the non-inverting input terminal of the comparator. The reference voltage input includes a potentiometer and a second voltage divider resistor. One end of the potentiometer is connected to the power supply bus of the control circuit, and the other end is connected in series with the second voltage divider resistor and grounded. The voltage division point between the potentiometer and the second voltage divider resistor is connected to the inverting input terminal of the comparator.

[0013] The second aspect of this utility model provides an inverter that includes the above-mentioned overheat protection structure.

[0014] Beneficial effects: Compared with the prior art, the present invention can achieve at least the following technical effects: 1. This utility model is equipped with a cooling component and a heat exchanger. When the temperature sensor detects that the inverter temperature is too high, it will control the cooling component to intervene and blow cold air into the inverter protective shell through the heat exchanger and bidirectional fan to force the inverter to cool down. This effectively reduces the probability of the inverter overheating and shutting down, and avoids unnecessary economic losses and safety hazards caused by the inverter overheating and shutting down.

[0015] 2. The cooling component of this utility model only intervenes when the inverter temperature is too high. When the inverter is working at normal temperature, the bidirectional fan can be used as an exhaust fan. The inverter dissipates heat through airflow, which reduces the power consumption of the inverter.

[0016] 3. The control circuit of this utility model is an analog circuit, which does not require complex chips and programming, and has a simple structure and high reliability. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the external structure of this utility model.

[0018] Figure 2 This is a schematic diagram of the internal structure of this utility model.

[0019] Figure 3 This is a schematic diagram of the refrigeration component structure of this utility model.

[0020] Figure 4 This is a schematic diagram of the heat exchanger structure of this utility model.

[0021] Figure 5 This is the control circuit diagram of this utility model.

[0022] In the diagram: 1. Inverter protective casing; 2. Heat dissipation window; 3. Heat sink; 4. Liquid cooling pump; 401. Heat conduction plate; 5. Semiconductor cooling chip; 6. Heat exchanger; 601. Upper casing; 602. Vertical pipe; 603. Fin; 604. Lower casing; 7. Temperature sensor; 8. Liquid inlet pipe; 9. Bidirectional fan; 10. Return pipe; 11. Transistor; 12. Relay; 13. Reversing switch; 14. Control circuit power supply bus; 15. Hysteresis resistor; 16. First voltage divider resistor; 17. Potentiometer; 18. Vent; 19. DC power supply; 20. Second voltage divider resistor; 21. Comparator. Detailed Implementation

[0023] The present invention will be further explained below with reference to specific implementation examples.

[0024] Please see Figure 1-5 This utility model first proposes an inverter overheat protection structure, including an inverter protective shell 1, a cooling component, a heat exchanger 6 and a temperature sensor 7. The inverter protective housing 1 has a vent 18 on the top and a heat dissipation window 2 at the rear. The heat exchanger 6 is installed inside the heat dissipation window 2, and a bidirectional fan 9 is provided between the heat dissipation window 2 and the heat exchanger 6. The cooling assembly includes a thermoelectric cooler 5, the cold end of which is connected to a liquid cooling pump 4, and the hot end of which is connected to a heat sink 3. The heat sink 3 is disposed outside the inverter protective housing 1. The liquid cooling pump is connected to a heat exchanger 6 through a coolant pipeline. The temperature sensor 7 is installed inside the inverter protective housing 1, and the temperature sensor 7 is electrically connected to the semiconductor cooling chip 5 and the bidirectional fan 9 through a control circuit.

[0025] like Figure 1 , Figure 2 As shown, when the inverter is operating within the normal temperature range, the bidirectional fan 9 exhausts the air inside the inverter protective case 1 to the outside through the heat dissipation window, and the outside air is replenished through the inverter protective case 1, using the air flow to remove the heat generated by the inverter during operation. When the temperature sensor 7 detects that the internal temperature of the inverter exceeds the threshold, the temperature sensor 7 controls the cooling component to intervene through the control circuit. Specifically, after the semiconductor cooling chip 5 is powered on, its cold end reduces the temperature of the coolant in the liquid cooling pump 4 through heat conduction. The coolant circulates between the heat exchanger 6 and the liquid cooling pump 4 through the coolant pipeline. At the same time, the control circuit changes the rotation direction of the bidirectional fan 9 motor, so that the bidirectional fan 9 blows the outside air into the inverter protective shell 1 through the heat dissipation window 2. The air exchanges heat with the heat exchanger 6, which reduces the air temperature. The cold air is used to force the internal temperature of the inverter to cool down, preventing the inverter from shutting down or being damaged due to overheating.

[0026] In this embodiment, the liquid cooling pump 4 is a contact type liquid cooling pump, and the bottom of the liquid cooling pump 4 is in contact with the cold end of the semiconductor cooling chip 5 through the heat-conducting plate 401.

[0027] like Figure 3 As shown, the cold end of the semiconductor cooling chip 5 transfers heat to the coolant in the liquid cooling pump 4 through the heat conduction plate 401, absorbing the heat of the coolant and keeping the coolant at a low temperature.

[0028] In this embodiment, the heat exchanger 6 is further configured to include an upper housing 601 and a lower housing 604, with a vertical pipe 602 connecting the upper housing 601 and the lower housing 604. Fins 603 are installed on the vertical pipe 602. The upper housing 601 is connected to the outlet of the liquid cooling pump 4 through a liquid inlet pipe 8, and the lower housing 604 is connected to the inlet of the liquid cooling pump 4 through a return pipe 10.

[0029] like Figure 4As shown, the low-temperature coolant pumped by the liquid-cooled pump 4 enters the upper chamber through the inlet pipe 8 and flows to the lower chamber 604 through multiple vertical pipes 602. The fins 603 are used to increase the contact area between the heat exchanger 6 and the air, so that the coolant can fully absorb the heat of the air. After the coolant exchanges heat with the air, it enters the liquid-cooled pump again through the lower chamber 604 and the return pipe 10, and so on.

[0030] In this embodiment, the control circuit is further configured such that the control circuit includes a comparator 21, the analog output of the temperature sensor 7 is connected to the non-inverting input of the comparator 21, the inverting input of the comparator 21 is connected to a reference voltage input, the output of the comparator 21 is connected to a relay 12 and a reversing switch 13 through a transistor 11, the thermoelectric cooler 5 is connected to a DC power supply 19 through the relay 12, and the bidirectional fan 9 is connected to a DC power supply 19 through the reversing switch 13.

[0031] like Figure 5 As shown, when the voltage output by the temperature sensor 7 exceeds the reference voltage, the output of the comparator 21 outputs a high level, which in turn controls the transistor 11 to conduct, energizing the coil K1 of the relay 12 and the coil K2 of the reversing switch 13, energizing the semiconductor cooling chip 5, and causing the motor of the bidirectional fan 9 to change its rotation direction.

[0032] In this embodiment, a hysteresis resistor 15 is connected in parallel between the output terminal and the non-inverting input terminal of the comparator 21.

[0033] When the output voltage of temperature sensor 7 fluctuates near the reference voltage, it may cause the output signal to jump repeatedly. By setting the hysteresis resistor 15, the signal output can be more stable and abnormal jumps can be avoided.

[0034] In this embodiment, the temperature sensor 7 is further configured as follows: one end of the NTC thermistor is connected to the power supply bus 14 of the control circuit, and the other end is connected in series with the first voltage divider resistor 16 and grounded. The voltage division point between the NTC thermistor and the first voltage divider resistor 16 is connected to the non-inverting input terminal of the comparator 21. The reference voltage input includes a potentiometer 17 and a second voltage divider resistor 20. One end of the potentiometer 17 is connected to the power supply bus 14 of the control circuit, and the other end is connected in series with the second voltage divider resistor 20 and grounded. The voltage division point between the potentiometer 17 and the second voltage divider resistor 20 is connected to the inverting input terminal of the comparator 21.

[0035] In this embodiment, an NTC thermistor is selected as the temperature sensing element. The NTC thermistor is located inside the inverter protective case 1 or mounted on the heat sink of the inverter motherboard. When the temperature of the NTC thermistor rises, its resistance decreases, causing the voltage across the first voltage divider resistor 16 to rise. This increases the input voltage at the non-inverting input of comparator 21. When the input voltage at the non-inverting input exceeds the reference voltage at the inverting input, the output of comparator 21 outputs a high level. The reference voltage can be set as needed by adjusting the resistance of potentiometer 17. In this embodiment, the control circuit power supply bus is 5V DC, while the bidirectional fan 9 and the thermoelectric cooler 5 are powered by 24V DC.

[0036] This invention also proposes an inverter that includes the above-mentioned overheat protection structure.

[0037] It should be noted that the overheat protection structure only serves to reduce the probability of the inverter overheating and shutting down. The inverter still retains overheat shutdown protection to prevent the inverter from burning out due to excessive temperature when the overheat protection structure in this embodiment fails.

[0038] In the description of this utility model, the term "multiple" refers to two or more. Unless otherwise explicitly defined, the terms "upper," "lower," "left," "right," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. The terms "connection," "installation," "fixing," etc., should be interpreted broadly. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection or an indirect connection through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0039] In the description of this utility model, the terms "one embodiment," "some embodiments," "specific embodiment," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this utility model. In this utility model, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0040] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

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