Switching tube temperature monitoring device and electronic equipment

Abstract

The utility model relates to the technical field of circuits, in particular to a switch tube temperature monitoring device and electronic equipment. The switching tube temperature monitoring device comprises a conduction voltage drop measuring unit and a temperature monitoring unit, wherein the first end of the temperature monitoring unit is connected with the base electrode of the switch tube, the first end of the conduction voltage drop measuring unit is connected with the collector electrode of the switch tube, and the second end of the conduction voltage drop measuring unit is connected with the second end of the temperature monitoring unit. By adopting the scheme, the temperature of the switch tube can be monitored.

Description

Technical Field

[0001] The utility model relates to the technical field of current detection, in particular to a switching tube temperature monitoring device and electronic equipment. Background Art

[0002] With the rapid advancement of frequency conversion technology, the devices used are also pursuing faster logic circuits. At the same time, to further miniaturize the controllers used in these devices, it is necessary to further increase the controller's power factor correction (PFC) carrier frequency and reduce the inductance. However, increasing the PFC carrier frequency and the faster switching speed will increase the temperature rise of the controller's switching transistors. If the temperature of the switching transistors cannot be effectively monitored, the junction temperature of the switching transistors may be too high and burn out the device. Utility Model Content

[0003] The utility model provides a switching tube temperature monitoring device and electronic equipment, the main purpose of which is to monitor the temperature of the switching tube.

[0004] According to one aspect of the present invention, a switching tube temperature monitoring device is provided, comprising: a conduction voltage drop measurement unit and a temperature monitoring unit; wherein,

[0005] The first end of the temperature monitoring unit is connected to the base of the switch tube, the first end of the conduction voltage drop measurement unit is connected to the collector of the switch tube, and the second end of the conduction voltage drop measurement unit is connected to the second end of the temperature monitoring unit.

[0006] Optionally, in one embodiment of the present invention, the temperature monitoring unit is used to control the on / off state of the switch tube, and determine the junction temperature of the switch tube according to the on-state voltage drop signal input by the on-state voltage drop measurement unit.

[0007] Optionally, in one embodiment of the present invention, the conduction voltage drop measurement unit includes a constant current source, a first resistance module, a second resistance module, a first diode module, a second diode module and an operational amplifier; wherein,

[0008] The output end of the constant current source is respectively connected to the first end of the first resistance module and the positive electrode of the first diode module, the second end of the first resistance module is respectively connected to the first end of the second resistance module and the inverting input end of the operational amplifier, the cathode of the first diode module is respectively connected to the positive electrode of the second diode module and the non-inverting input end of the operational amplifier, the cathode of the second diode module is the first end of the conduction voltage drop measurement unit, and the connection point between the second end of the second resistance module and the output end of the operational amplifier is the second end of the conduction voltage drop measurement unit.

[0009] Optionally, in one embodiment of the present invention, the conduction voltage drop measurement unit further includes a third resistance module; wherein,

[0010] The first end of the third resistor module is connected to the output end of the constant current source, and the second end of the third resistor module is connected to the first end of the first resistor module and the anode of the first diode module respectively.

[0011] Optionally, in one embodiment of the present invention, the models of all diodes in the first diode module and the second diode module are the same, and the first ratio between the resistance corresponding to the first resistor module and the resistance corresponding to the second resistor module is determined by the second ratio between the number of diodes corresponding to the first diode module and the number of diodes corresponding to the second diode module.

[0012] Optionally, in one embodiment of the present invention, the first ratio and the second ratio are both 1:2.

[0013] Optionally, in one embodiment of the present invention, the temperature monitoring unit includes a control subunit; wherein,

[0014] The first end of the control subunit is connected to the base of the switch tube, and is used to output a pulse width modulation signal to the base of the switch tube to control the on / off state of the switch tube;

[0015] The second end of the control subunit is connected to the second end of the conduction voltage drop measurement unit, and is used to receive the conduction voltage drop signal input by the conduction voltage drop measurement unit and determine the junction temperature of the switch tube according to the conduction voltage drop signal.

[0016] Optionally, in one embodiment of the present invention, the temperature monitoring unit further includes a driving protection subunit and a fourth resistance module; wherein,

[0017] The first end of the driving protection subunit is connected to the first end of the control subunit, the second end of the driving protection subunit is connected to the first end of the fourth resistance module, and the second end of the fourth resistance module is connected to the base of the switching tube.

[0018] Optionally, in one embodiment of the present invention, the temperature monitoring unit further includes an analog-to-digital conversion subunit; wherein,

[0019] The first end of the analog-to-digital conversion subunit is connected to the second end of the conduction voltage drop measurement unit, and the second end of the analog-to-digital conversion subunit is connected to the second end of the control subunit.

[0020] According to another aspect of the present invention, an electronic device is provided, comprising: a switching tube and the switching tube temperature monitoring device according to any one of the aforementioned aspects.

[0021] In summary, the switching tube temperature monitoring device and electronic device provided by the embodiments of the present invention measure the on-state voltage drop of the switching tube through a on-state voltage drop measuring unit. Since there is a good linear relationship between the on-state voltage drop Vce between the collector and the emitter of the switching tube and the junction temperature, the temperature monitoring unit can determine the junction temperature of the switching tube based on the on-state voltage drop measured by the on-state voltage drop measuring unit, and can effectively monitor the temperature of the switching tube.

[0022] It should be understood that the above general description and the following detailed description are merely exemplary and explanatory and are not restrictive of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present invention, and together with the description, serve to explain the principles of the present invention.

[0024] Figure 1 A schematic structural diagram of a switching tube temperature monitoring device provided by an embodiment of the present utility model;

[0025] Figure 2 A schematic structural diagram of a conduction voltage drop measurement unit provided by an embodiment of the present utility model;

[0026] Figure 3 A schematic structural diagram of a switching tube temperature monitoring device provided by another embodiment of the present invention;

[0027] Figure 4 This is a working flow chart of a switching tube temperature monitoring device provided by an embodiment of the utility model.

[0028] Description of reference numerals: switch tube Q1, first resistor R1, second resistor R2, third resistor R3, fourth resistor R4, first diode D1, second diode D2, third diode D3, constant current source DC, operational amplifier IC1B. DETAILED DESCRIPTION

[0029] Some embodiments of the present invention will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. Various changes, modifications and equivalents of the structures described herein will become apparent after understanding the present invention. For example, the connection relationships of the structures described herein are merely examples and are not limited to those connection relationships set forth herein, but can be changed as becomes apparent after understanding the present invention, except for connections that must be made in specific connection relationships. In addition, for the purpose of improving clarity and brevity, descriptions of features known in the art may be omitted.

[0030] The embodiments described in the following embodiments of the present invention do not represent all embodiments consistent with the present invention. Instead, they are merely examples of structures consistent with some aspects of the present invention as detailed in the appended claims.

[0031] In related technologies, the temperature of the switching tube is detected by physical contact, optical temperature measurement and other methods. However, when applied to products, the physical contact temperature measurement solution increases the cost of the product, and the optical temperature measurement method cannot detect the device temperature in real time. Faced with relatively complex usage environments such as air-conditioning outdoor units, various situations cannot be fully simulated clearly during the design phase. When air conditioners and other related products are used in harsh high-temperature environments and poorly ventilated places, the switching tube has poor heat dissipation, and the air conditioners and other related products do not reduce the output power and current of the load, which may cause the junction temperature of the switching tube to be too high and damaged.

[0032] The present invention will be described in detail below with reference to specific embodiments.

[0033] Figure 1 This is a schematic diagram of the structure of a switch tube temperature monitoring device provided by an embodiment of the present utility model. Figure 1 As shown, the switch tube temperature monitoring device includes: a conduction voltage drop measurement unit and a temperature monitoring unit; wherein,

[0034] The first end of the temperature monitoring unit is connected to the base of the switch tube Q1, the first end of the conduction voltage drop measurement unit is connected to the collector of the switch tube Q1, and the second end of the conduction voltage drop measurement unit is connected to the second end of the temperature monitoring unit.

[0035] According to some embodiments, the type of the switch tube Q1 includes but is not limited to a bipolar junction transistor (BJT), a gate turn-off thyristor (GTO), an insulated gate bipolar transistor (IGBT), an integrated gate commutated thyristor (IGCT), and a metal oxide semiconductor field effect transistor (MOSFET), etc.

[0036] In some embodiments, during the conduction process of switch Q1, the generation of the on-state voltage drop is primarily related to its internal structure and operating principle. For example, when a forward voltage is applied between the base and emitter of an IGBT, and this voltage is greater than its turn-on voltage, a conductive channel is formed within the MOSFET in the IGBT. This channel provides base current to the PNP transistor in the IGBT, thereby turning on the entire IGBT. In the on-state, holes injected from the P+ region into the N- region modulate the conductivity of the N- region, reducing the resistance of the N- region. This conductivity modulation effect enables a high-voltage IGBT to have a smaller on-state voltage drop when it is on. This voltage drop is the forward voltage drop generated by the IGBT when it is on, also known as the on-state voltage drop.

[0037] It should be noted that the on-state voltage drop (Vce) between the collector and emitter of switch Q1 has a good linear relationship with the junction temperature. For example, the temperature sensitivity of the on-state voltage drop (Vce) of an IGBT is generally between 1 and 10 mV / °C. In other words, the junction temperature of switch Q1 can be indirectly calculated by measuring the on-state voltage drop of switch Q1.

[0038] The junction temperature of the switch tube Q1 refers to the actual operating temperature of the switch tube Q1 .

[0039] According to some embodiments, the temperature monitoring unit may be used to control the on / off state of the switch tube Q1 and determine the junction temperature of the switch tube Q1 according to the on-state voltage drop signal Uce_on input by the on-state voltage drop measurement unit.

[0040] That is to say, during the operation of the switching tube temperature monitoring device, first, the temperature monitoring unit can be used to control the switching tube Q1 to be in the on state; then, the on-state voltage drop of the switching tube Q1 in the on state can be measured by the on-state voltage drop measurement unit; finally, the junction temperature of the switching tube Q1 can be determined based on the measured on-state voltage drop.

[0041] Optionally, the conduction voltage drop measurement unit includes a constant current source DC, a first resistor module, a second resistor module, a first diode module, a second diode module and an operational amplifier IC1B; wherein,

[0042] The output end of the constant current source DC is respectively connected to the first end of the first resistor module and the positive electrode of the first diode module, the second end of the first resistor module is respectively connected to the first end of the second resistor module and the inverting input end of the operational amplifier IC1B, the cathode of the first diode module is respectively connected to the positive electrode of the second diode module and the non-inverting input end of the operational amplifier IC1B, the cathode of the second diode module is the first end of the conduction voltage drop measurement unit, and the connection point between the second end of the second resistor module and the output end of the operational amplifier IC1B is the second end of the conduction voltage drop measurement unit.

[0043] It should be noted that by using a constant current source DC to drive the switch tube Q1 with a constant current, the anti-interference ability of the conduction voltage drop measurement unit can be increased, with higher acquisition accuracy and lower temperature influence. In addition, there is good consistency between different acquisition boards under the same topology circuit of the switch tube Q1, which can realize high-precision online monitoring of the junction temperature of the switch tube Q1.

[0044] According to some embodiments, all diodes in the first diode module and the second diode module are of the same model, and a first ratio between the resistance value corresponding to the first resistor module and the resistance value corresponding to the second resistor module is determined by a second ratio between the number of diodes corresponding to the first diode module and the number of diodes corresponding to the second diode module. For example, both the first ratio and the second ratio may be 1:2.

[0045] Take a scenario as an example, Figure 2 This is a schematic diagram of the structure of a conduction voltage drop measurement unit provided by an embodiment of the present utility model. Figure 2 As shown, the first resistor module includes a first resistor R1, the second resistor module includes a second resistor R2, the first diode module includes a first diode D1, and the second diode module includes a second diode D2 and a third diode D3 connected in series; since the second ratio is 1:2, it can be determined that the resistance of the second resistor R2 is twice the resistance of the first resistor R1.

[0046] According to some embodiments, the conduction voltage drop measurement unit further includes a third resistance module; wherein,

[0047] A first end of the third resistor module is connected to the output end of the constant current source DC, and a second end of the third resistor module is connected to the first end of the first resistor module and the anode of the first diode module respectively.

[0048] In some embodiments, the third resistor module can serve as a protective resistor to protect the on-state voltage drop measurement unit and the switch tube Q1 , thereby improving the safety of the switch tube temperature monitoring device during use.

[0049] In some embodiments, the third resistor module may include at least one resistor. Figure 2 As shown, the third resistor module includes a third resistor R3.

[0050] Optionally, the temperature monitoring unit includes a control subunit; wherein,

[0051] The first end of the control subunit is connected to the base of the switch tube Q1, and is used to output a pulse width modulation (PWM) signal to the base of the switch tube Q1 to control the on / off state of the switch tube Q1;

[0052] The second end of the control subunit is connected to the second end of the conduction voltage drop measurement unit, and is used to receive the conduction voltage drop signal Uce_on input by the conduction voltage drop measurement unit, and determine the junction temperature of the switch tube Q1 according to the conduction voltage drop signal Uce_on.

[0053] According to some embodiments, the control subunit may be, for example, a microcontroller unit (MCU).

[0054] Optionally, Figure 3 This is a schematic diagram of the structure of a switch tube temperature monitoring device provided by an embodiment of the present utility model. Figure 3 As shown, the temperature monitoring unit further includes a driving protection subunit and a fourth resistance module; wherein,

[0055] The first end of the driving protection subunit is connected to the first end of the control subunit, the second end of the driving protection subunit is connected to the first end of the fourth resistor module, and the second end of the fourth resistor module is connected to the base of the switch tube Q1.

[0056] According to some embodiments, the PWM signal sent by the MCU drives the protection subunit to realize the on / off control of the switch tube Q1, which can improve the accuracy and safety of the control.

[0057] In some embodiments, the driving protection subunit may be, for example, a gate driver.

[0058] According to some embodiments, parasitic inductance between the base and emitter of the switch tube may cause oscillation of the base voltage. The oscillation of the base voltage can be suppressed by providing the fourth resistor module.

[0059] In some embodiments, the fourth resistor module may include at least one resistor. Figure 3As shown, the fourth resistor module includes a fourth resistor R4.

[0060] Alternatively, as Figure 3 As shown, the temperature monitoring unit also includes an analog to digital converter (ADC) subunit; wherein,

[0061] The first end of the analog-to-digital conversion subunit is connected to the second end of the conduction voltage drop measurement unit, and the second end of the analog-to-digital conversion subunit is connected to the second end of the control subunit.

[0062] According to some embodiments, the conduction voltage drop signal Uce_on output by the conduction voltage drop measurement unit is an analog signal, and the analog-to-digital conversion subunit can convert the analog signal into a digital signal. Compared with analog-to-digital conversion of the conduction voltage drop signal Uce_on by an MCU, the conversion accuracy is higher.

[0063] Optionally, Figure 4 This is a working diagram of a switch tube temperature monitoring device provided by the embodiment of the present utility model. Figure 4 As shown, first, the MCU sends a PWM signal to the switch tube Q1; then, when the gate of the switch tube Q1 is turned off, the on-state voltage drop measurement unit outputs the on-state voltage drop signal Uce_on, and the analog-to-digital conversion subunit performs ADC sampling to convert the on-state voltage drop signal Uce_on into a digital signal; then, the junction capacitance in the switch tube Q1 is kept in a discharged state, and the MCU calculates the junction temperature data based on the digital value corresponding to the digital signal; finally, the MCU uploads the calculated junction temperature data.

[0064] According to some embodiments, after the calculated junction temperature data is uploaded, the calculated junction temperature data can be compared with the standard temperature; when the calculated junction temperature data is less than or equal to the standard temperature, it indicates that the circuit in which the switch tube Q1 is located is working normally; when the calculated junction temperature data is greater than the calculated junction temperature data, it indicates that the temperature of the switch tube Q1 is too high, and an alarm information is output to indicate that the switch tube Q1 is over-temperature protected, and at the same time, the PWM signal is not output to shut down the drive of the switch tube Q1, thereby protecting the switch tube Q1.

[0065] In some embodiments, the circuit in which the switch tube Q1 is located includes but is not limited to a high-frequency PFC circuit, a high-power density power electronic circuit, an IGBT module without physical temperature measurement, and other control circuits.

[0066] In summary, the switching tube temperature monitoring device provided by the embodiment of the present invention measures the on-state voltage drop of the switching tube through a on-state voltage drop measuring unit. Since there is a good linear relationship between the on-state voltage drop Vce between the collector and the emitter of the switching tube and the junction temperature, the temperature monitoring unit can determine the junction temperature of the switching tube based on the on-state voltage drop measured by the on-state voltage drop measuring unit, and can effectively monitor the temperature of the switching tube. The circuit structure is simple and the cost is low.

[0067] According to an embodiment of the present invention, the present invention further provides an electronic device.

[0068] The electronic device includes a switching tube and a switching tube temperature monitoring device as shown in any of the above embodiments.

[0069] In summary, the electronic device provided by the embodiment of the present invention can effectively monitor the temperature of the switching tube, thereby reducing the damage to the device caused by excessive temperature of the switching tube and reducing the after-sales failure rate.

[0070] Furthermore, the word "exemplary" is used herein to mean serving as an example, instance, or illustration. Any aspect or design described herein as "exemplary" is not necessarily to be construed as advantageous over other aspects or designs. Rather, the use of the word exemplary is intended to present concepts in a concrete manner. As used herein, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." That is, unless otherwise specified or clear from the context, "X applies to A or B" is intended to mean any of the natural inclusive permutations. That is, if X applies to A; X applies to B; or X applies to both A and B, then "X applies to A or B" satisfies any of the aforementioned instances. Furthermore, the articles "a" and "an," as used in this application and the appended claims, are generally understood to mean "one or more," unless otherwise specified or clear from the context to refer to the singular form.

[0071] Similarly, although the present invention has been shown and described with respect to one or more implementations, after reading and understanding the specification and drawings, those skilled in the art will think of equivalent variations and modifications. The present invention includes all such modifications and variations and is limited only by the scope of the claims. In particular, with respect to the various functions performed by the components described above (e.g., elements, resources, etc.), unless otherwise indicated, the terms used to describe such components are intended to correspond to any component (functionally equivalent) that performs the specific functions of the described components, even if structurally not equivalent to the structure of the invention. In addition, although the specific features of the present invention may have been described with respect to only one of several implementations, such features may be combined with one or more other features of other implementations as may be desired and beneficial to any given or specific application. In addition, with respect to the "including", "having", "having", "having", or variations thereof used in the specific embodiments or claims, such terms are intended to be inclusive in a manner similar to the term "comprising".

[0072] Other embodiments of the present invention will readily occur to those skilled in the art after considering the specification and practicing the invention herein. This application is intended to cover any variations, uses, or adaptations of the present invention that follow the general principles of the present invention and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, with the true scope and spirit of the present invention being indicated by the following claims.

[0073] It should be understood that the present invention is not limited to the precise structure described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A switching tube temperature monitoring device, characterized in that: include: On-state voltage drop measurement unit and temperature monitoring unit; wherein, The first end of the temperature monitoring unit is connected to the base of the switching tube, the first end of the conduction voltage drop measurement unit is connected to the collector of the switching tube, and the second end of the conduction voltage drop measurement unit is connected to the second end of the temperature monitoring unit; The conduction voltage drop measurement unit includes a constant current source, a first resistor module, a second resistor module, a first diode module, a second diode module and an operational amplifier; wherein, The output end of the constant current source is respectively connected to the first end of the first resistance module and the positive electrode of the first diode module, the second end of the first resistance module is respectively connected to the first end of the second resistance module and the inverting input end of the operational amplifier, the cathode of the first diode module is respectively connected to the positive electrode of the second diode module and the non-inverting input end of the operational amplifier, the cathode of the second diode module is the first end of the conduction voltage drop measurement unit, and the connection point between the second end of the second resistance module and the output end of the operational amplifier is the second end of the conduction voltage drop measurement unit.

2. The switching tube temperature monitoring device according to claim 1, characterized in that: The temperature monitoring unit is used to control the on / off state of the switch tube and determine the junction temperature of the switch tube according to the on-state voltage drop signal input by the on-state voltage drop measurement unit.

3. The switching tube temperature monitoring device according to claim 1, characterized in that: The conduction voltage drop measurement unit further includes a third resistance module; wherein, The first end of the third resistor module is connected to the output end of the constant current source, and the second end of the third resistor module is connected to the first end of the first resistor module and the anode of the first diode module respectively.

4. The switching tube temperature monitoring device according to claim 1, characterized in that: The models of all diodes in the first diode module and the second diode module are the same, and the first ratio between the resistance corresponding to the first resistor module and the resistance corresponding to the second resistor module is determined by the second ratio between the number of diodes corresponding to the first diode module and the number of diodes corresponding to the second diode module.

5. The switching tube temperature monitoring device according to claim 4, characterized in that: The first ratio and the second ratio are both 1:

2.

6. The switching tube temperature monitoring device according to claim 1, characterized in that: The temperature monitoring unit includes a control subunit; wherein, The first end of the control subunit is connected to the base of the switch tube, and is used to output a pulse width modulation signal to the base of the switch tube to control the on / off state of the switch tube; The second end of the control subunit is connected to the second end of the conduction voltage drop measurement unit, and is used to receive the conduction voltage drop signal input by the conduction voltage drop measurement unit and determine the junction temperature of the switch tube according to the conduction voltage drop signal.

7. The switching tube temperature monitoring device according to claim 6, characterized in that: The temperature monitoring unit further includes a driving protection subunit and a fourth resistance module; wherein, The first end of the driving protection subunit is connected to the first end of the control subunit, the second end of the driving protection subunit is connected to the first end of the fourth resistance module, and the second end of the fourth resistance module is connected to the base of the switching tube.

8. The switching tube temperature monitoring device according to claim 6, characterized in that: The temperature monitoring unit also includes an analog-to-digital conversion subunit; wherein, The first end of the analog-to-digital conversion subunit is connected to the second end of the conduction voltage drop measurement unit, and the second end of the analog-to-digital conversion subunit is connected to the second end of the control subunit.

9. An electronic device, characterized in that: include: A switching tube and a switching tube temperature monitoring device according to any one of claims 1 to 8.

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