Temperature detection circuit, energy storage power supply and power conversion device

Abstract

The application provides a temperature detection circuit, an energy storage power supply and a power conversion device, wherein a thermistor and a voltage dividing resistor are connected in series to form a voltage sampling circuit, a first end of the voltage sampling circuit is used for being connected with a source electrode of a power tube, an input end of an isolated power supply circuit is connected with a power supply, output ends of the isolated power supply circuit are respectively connected with a second end and a first end of the thermistor and the voltage dividing resistor connected in series, a power supply end of a control module is connected with the power supply, an input end of the control module is connected with an output end of the isolated sampling circuit, and two sampling input ends of the isolated sampling circuit are respectively connected with two ends of the thermistor. The temperature detection circuit does not need to distinguish the floating ground or the common ground of the power tube and the control module, is suitable for various power tube circuits, and has higher universality.

Description

Technical Field

[0001] This application relates to the field of power semiconductor technology, and in particular to a temperature detection circuit, an energy storage power supply, and a power conversion device. Background Technology

[0002] Currently, the most common power semiconductor devices on the market include insulated-gate bipolar transistors (IGBTs) and metal-oxide-semiconductor field-effect transistors (MOSFETs). These power devices generate losses during operation, causing the temperature to rise. Therefore, it is necessary to monitor the temperature at all times to prevent temperature runaway and damage.

[0003] In related technologies, for full-bridge or half-bridge circuits, the source of the switching transistor on the bridge arm is a floating point, which makes it impossible to directly sample it, thus making temperature detection impossible. Utility Model Content

[0004] In view of this, this application provides a temperature detection circuit, an energy storage power supply, and a power conversion device, which have high temperature detection accuracy, high reliability, and are applicable to various circuits, and have high versatility.

[0005] According to a first aspect of the embodiments of this application, a temperature detection circuit for a power transistor is provided for detecting the temperature of the power transistor. The temperature detection circuit includes a voltage sampling circuit, an isolation sampling circuit, an isolation power supply circuit, a power supply, and a control module. The voltage sampling circuit includes a thermistor and a voltage divider resistor connected in series, and the first terminal of the voltage sampling circuit is used to connect to the source of the power transistor. The input terminal of the isolated power supply circuit is connected to the power supply, and the positive and negative terminals of the output terminal of the isolated power supply circuit are connected to the second terminal and the first terminal of the voltage sampling circuit, respectively. The power supply terminal of the control module is connected to the power supply, and the input terminal of the control module is connected to the output terminal of the isolated sampling circuit. The two sampling input terminals of the isolated sampling circuit are connected to the two ends of the thermistor, respectively.

[0006] In one optional implementation, The power transistors include the upper or lower switching transistors of the bridge arms in a full-bridge or half-bridge circuit, or the main power transistors in a boost / buck circuit.

[0007] In one optional implementation, The control module and the source of the power transistor are not grounded together.

[0008] In one optional implementation, The source of the power transistor is connected to a first reference ground, and the ground terminal of the control module is connected to a second reference ground.

[0009] In one optional implementation, The power transistor is the upper switching transistor of the bridge arm in a full-bridge or half-bridge circuit. The source of the power transistor is grounded through the lower switching transistor, and the grounding terminal of the control module is grounded.

[0010] In one optional implementation, The first end of the thermistor forms the first end of the voltage sampling circuit. The first end of the thermistor is surface-mount soldered to the source pad of the power transistor. The second end of the thermistor is connected to the voltage divider resistor to realize the series connection of the thermistor and the voltage divider resistor.

[0011] In one optional implementation, The isolated power supply circuit includes an isolated DC power supply circuit without a feedback sampling circuit or an isolated DC power supply circuit with a feedback sampling circuit.

[0012] In one optional implementation, The isolation sampling circuit includes an isolation sampling chip and / or an isolation amplifier.

[0013] According to a second aspect of the embodiments of this application, an energy storage power supply is provided, the energy storage power supply including an energy storage unit, a power conversion circuit and a temperature detection circuit as described in any of the first aspects, the temperature detection circuit being used to detect the temperature of the power transistor in the power conversion circuit.

[0014] According to a third aspect of the embodiments of this application, a power conversion device is provided, the power conversion device including a power conversion circuit and a temperature detection circuit as described in any of the first aspects, the temperature detection circuit being used to detect the temperature of a power transistor in the power conversion circuit.

[0015] The technical solution provided by the embodiments of this application has the following beneficial effects: In this application, a thermistor and a voltage divider resistor are connected in series to form a voltage sampling circuit. After being connected in series, one end of the thermistor and the voltage divider resistor is connected to the source of the power transistor so that the voltage sampling is correlated with the temperature of the power transistor. The power supply, control module, isolated power supply circuit, and isolated sampling circuit together constitute the temperature detection circuit of the power transistor. The cost is low. Moreover, since the temperature detection circuit of this application adopts the isolated power supply and isolated sampling scheme, it can perform temperature sampling of the power transistor at any position, without requiring the power transistor and the control module to share a common ground. That is, the temperature detection circuit of this application has stronger versatility and can solve the problem that the power transistor and the control module cannot be directly sampled because they do not share a common ground. For example, for a full-bridge circuit, the temperature detection circuit of this application can not only sample the temperature of the lower transistor of the full-bridge circuit, but also sample the temperature of the upper transistor of the full-bridge circuit, which can improve the versatility of the temperature detection circuit.

[0016] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit this application. Attached Figure Description

[0017] The accompanying drawings, which are incorporated in and form 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.

[0018] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] One or more embodiments are illustrated by way of example with reference numerals in the accompanying drawings. These illustrations do not constitute a limitation on the embodiments. Elements with the same reference numerals in the drawings are denoted as similar elements. Unless otherwise stated, the figures in the drawings are not to be limited by scale.

[0020] Figure 1 This is a schematic diagram of a temperature detection circuit according to an exemplary embodiment.

[0021] Figure 2 This is a schematic diagram of the temperature detection circuit in the first embodiment.

[0022] Figure 3 This is a schematic diagram of the temperature detection circuit in the second embodiment.

[0023] Figure 4 This is a schematic diagram of the temperature detection circuit in the third embodiment.

[0024] Figure 5 This is a schematic diagram of the temperature detection circuit in the fourth embodiment.

[0025] Figure 6 This is a schematic diagram of the temperature detection circuit in the fifth embodiment.

[0026] Figure 7 This is a schematic diagram of the temperature detection circuit according to the sixth embodiment.

[0027] Figure 8 This is a schematic diagram of the temperature detection circuit according to the seventh embodiment.

[0028] Figure 9 This is a schematic diagram of the temperature detection circuit according to the eighth embodiment.

[0029] Figure 10 This is a schematic diagram of an isolated DC power supply circuit without feedback sampling, according to an exemplary embodiment.

[0030] Figure 11 This is a schematic diagram of an isolated DC power supply circuit with feedback sampling circuit according to an exemplary embodiment.

[0031] Figure 12 This is a schematic diagram of an isolated sampling circuit according to an exemplary embodiment. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0033] The following disclosure provides numerous different embodiments or examples for implementing various structures of the present invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples. Such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention; however, those skilled in the art will recognize the applicability of other processes and / or the use of other materials.

[0034] For ease of understanding, the terminology used in the embodiments of this application will be explained first.

[0035] And / or: such as A and / or B, refers to three possibilities: A or B, or A and B.

[0036] Multiple: refers to two or more.

[0037] Connection: should be interpreted broadly. For example, the connection between A and B can be a direct connection between A and B, or an indirect connection between A and B through an intermediary.

[0038] To address the technical problem in related technologies where the source of some power transistors is a floating point, making direct sampling impossible and thus temperature detection impossible, this application provides a temperature detection circuit and an energy storage power supply. The circuit offers high temperature detection accuracy, high reliability, applicability to various circuits, and high versatility.

[0039] In this application, a thermistor and a voltage divider resistor are connected in series to form a voltage sampling circuit. After being connected in series, one end of the thermistor and the voltage divider resistor is connected to the source of the power transistor to correlate the voltage sampling with the temperature of the power transistor. The power supply, control module, isolated power supply circuit, and isolated sampling circuit together constitute the temperature detection circuit for the power transistor. This design results in lower cost. Furthermore, because this application's temperature detection circuit employs isolated power supply and isolated sampling, it can sample the temperature of the power transistor at any location without requiring the power transistor and control module to share a common ground. This means the temperature detection circuit has greater versatility and solves the problem of direct sampling when the power transistor and control module are not grounded. For example, for a full-bridge circuit, this application's temperature detection circuit can sample the temperature of not only the lower transistor but also the upper transistor, improving the versatility of the temperature detection circuit.

[0040] In one exemplary embodiment, reference Figures 1 to 9 As shown, a temperature detection circuit is provided for detecting the temperature of a power transistor Q. The power transistor Q may include, for example, an insulated-gate bipolar transistor (IGBT), a metal-oxide-semiconductor field-effect transistor (MOSFET), etc. This application does not limit the type of transistor.

[0041] The temperature detection circuit includes a voltage sampling circuit 500, an isolation sampling circuit 100, an isolation power supply circuit 200, a power supply 300, and a control module 400. The power supply 300 can provide multiple voltage outputs, providing power output to the isolation power supply circuit 200 and a stable operating voltage to the control module 400.

[0042] The voltage sampling circuit 500 includes a thermistor NTC and a voltage divider resistor R1 connected in series. The first terminal of the voltage sampling circuit 500 is connected to the source of the power transistor Q. The positions of the thermistor NTC and the voltage divider resistor R1 in the voltage sampling circuit 500 can be interchanged. That is, in this embodiment, the first terminal of the voltage sampling circuit 500 can be either the free terminal of the thermistor NTC or the free terminal of the voltage divider resistor R1.

[0043] It should be noted that the free end of the thermistor NTC refers to the end of the thermistor NTC that is not directly connected to the voltage divider resistor R1. For example, if the thermistor NTC includes a first end and a second end, and the second end of the thermistor NTC is connected to the voltage divider resistor R1, then the first end of the thermistor NTC is the free end. Similarly, the free end of the voltage divider resistor R1 refers to the end of the voltage divider resistor R1 that is not directly connected to the thermistor NTC. For example, if the voltage divider resistor R1 includes a first end and a second end, and the first end of the voltage divider resistor R1 is connected to the thermistor NTC, then the second end of the voltage divider resistor R1 is the free end.

[0044] The input terminal of the isolation power supply circuit 200 is connected to the power supply 300. The positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the second and first terminals of the series connection between the thermistor NTC and the voltage divider resistor R1, respectively. The isolation power supply circuit 200 provides the input voltage provided by the power supply 300 to the voltage sampling circuit 500 after isolation processing by a transformer, so as to achieve isolated power supply during temperature detection. The power supply terminal of the control module 400 is connected to the power supply 300. The input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The isolation sampling circuit 100 refers to a circuit unit that can perform electrically isolated sampling. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively, thereby realizing isolated sampling.

[0045] It should be noted that, because the temperature detection circuit of this embodiment adopts an isolated power supply scheme, it can sample the temperature of the power transistor Q at any location. Therefore, the power transistor Q in this application can include the upper switching transistor Q1 and / or the lower switching transistor Q2 of the bridge arm in a full-bridge or half-bridge circuit, or the main power transistor Q in a boost / buck circuit, without limitation. That is, the temperature detection circuit of this application has greater versatility. Similarly, because the temperature detection circuit of this embodiment adopts an isolated power supply scheme, the source of the control module 400 and the power transistor Q can share a common ground or not, thereby further improving the versatility of the temperature detection circuit of this application.

[0046] In the first embodiment, refer to Figure 2As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the first terminal of the thermistor NTC is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, and the source of the power transistor Q is connected to the first reference ground GND1. The ground terminal of the control module 400 is connected to the second reference ground GND2. In this case, the power transistor Q and the control module 400 are not grounded together. Since one end of the thermistor NTC is located close to the source of the power transistor Q, the temperature of the thermistor NTC is equivalent to the temperature of the power transistor Q. When the temperature of the power transistor Q rises, the temperature of the thermistor NTC also changes. Due to the characteristics of the thermistor NTC, its voltage will also change. Therefore, by sampling the thermistor NTC, the temperature of the power transistor Q can be determined.

[0047] In the second embodiment, refer to Figure 3 As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the first terminal of the thermistor NTC is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, and the source of the power transistor Q and the ground terminal of the control module 400 are connected to the same reference ground, i.e., they are common grounded.

[0048] In the third embodiment, reference is made to Figure 4As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the first terminal of the thermistor NTC is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively. Additionally, in this embodiment, the power transistor Q is the upper switching transistor Q1 of the bridge arm in a full-bridge or half-bridge circuit. This upper switching transistor Q1 is connected to the first reference ground GND1 via the lower switching transistor Q2, and the ground terminal of the control module 400 is connected to the second reference ground GND2. At this time, since the power transistor Q is the upper switch Q1 of the bridge arm, its source is grounded through the lower switch Q2, and the source potential is a floating point.

[0049] In the fourth embodiment, reference is made to Figure 5 As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the first terminal of the thermistor NTC is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively. In addition, the power transistor Q in this embodiment is the upper switching transistor Q1 of the bridge arm in a full-bridge or half-bridge circuit. This upper switching transistor Q1 is grounded through the lower switching transistor Q2. The ground terminal of the control module 400 is connected to ground, and both are connected to the same reference ground. Similarly, since the power transistor Q is the upper switch Q1 of the bridge arm, its source is grounded through the lower switch Q2, and the source potential is a floating point. Even if the bridge arm and the control module 400 are connected to the same reference ground and are set to a common ground, since the source of the upper switch Q1 is a floating point, the power transistor Q and the control module 400 are still not set to a common ground.

[0050] In the fifth embodiment, reference is made to Figure 6As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the second terminal of the voltage divider resistor R1 is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, and the source of the power transistor Q is connected to the first reference ground GND1. The ground terminal of the control module 400 is connected to the second reference ground GND2. In this configuration, the power transistor and the control module are not grounded together.

[0051] In the sixth embodiment, reference is made to Figure 7 As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the second terminal of the voltage divider resistor R1 is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, and the source of the power transistor Q and the ground terminal of the control module 400 are connected to the same reference ground, i.e., grounding is implemented.

[0052] In the seventh embodiment, reference is made to Figure 8 As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the second terminal of the voltage divider resistor R1 is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively. In this embodiment, the power transistor Q is the upper switching transistor Q1 of the bridge arm in a full-bridge or half-bridge circuit. This upper switching transistor Q1 is connected to the first reference ground GND1 via the lower switching transistor Q2, and the ground terminal of the control module 400 is connected to the second reference ground GND2. At this time, since the power transistor Q is the upper switch Q1 of the bridge arm, its source is grounded through the lower switch Q2, and the source potential is a floating point.

[0053] In the eighth embodiment, reference Figure 9 As shown, the second terminal of the thermistor NTC is connected to the first terminal of the voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. Furthermore, the second terminal of the voltage divider resistor R1 is connected to the source of the power transistor Q. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300, and the positive and negative terminals of the output terminal of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300, and the input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively. In this embodiment, the power transistor Q is the upper switching transistor Q1 of the bridge arm in a full-bridge or half-bridge circuit. This upper switching transistor Q1 is grounded through the lower switching transistor Q2. The grounding terminal of the control module 400 is connected to ground, and both are connected to the same reference ground. Similarly, since the power transistor Q is the upper switch Q1 of the bridge arm, its source is grounded through the lower switch Q2, and the source potential is a floating point. Even if the bridge arm and the control module 400 are connected to the same reference ground and are set to a common ground, since the source of the upper switch Q1 is a floating point, the power transistor Q and the control module 400 are still not set to a common ground.

[0054] In this application, a thermistor NTC and a voltage divider resistor R1 are connected in series to form a voltage sampling circuit 500. Together with a power supply 300, a control module 400, an isolated power supply circuit 200, and an isolated sampling circuit 100, they form a temperature detection circuit for the power transistor Q. This circuit offers high temperature detection accuracy and reliability. Furthermore, because the temperature detection circuit in this application employs an isolated power supply scheme, it can sample the temperature of the power transistor Q at any location, making the temperature detection circuit more versatile. In other words, the temperature detection circuit of this embodiment offers high temperature detection accuracy, high reliability, and applicability to various circuits, demonstrating high versatility.

[0055] In one exemplary embodiment, reference Figures 1 to 5 As shown, a temperature detection circuit is provided for detecting the temperature of a power transistor Q. In this embodiment, the second terminal of a thermistor NTC is connected to a voltage divider resistor R1 to achieve series connection between the thermistor NTC and the voltage divider resistor R1. The first terminal of the thermistor NTC is surface-mount soldered to the source pad of the power transistor Q, so that the first terminal of the series connection between the thermistor NTC and the voltage divider resistor R1 is connected to the source of the power transistor Q.

[0056] It should be noted that in related technologies, thermistors (NTCs) are generally screwed onto the heat sink of power devices or glued to the side of the power devices. This often requires manual tightening of screws or application of glue, which is time-consuming and depends on the precision of manual operation, making the operation more cumbersome. The auxiliary materials such as screws and glue increase material costs and require additional labor time, resulting in higher costs. There is a difference in thermal resistance between the thermistor (NTC) and the power transistor (Q), which leads to a lag in temperature response and a large detection error. Mechanical fixation is prone to loosening due to vibration, and the glue may age and fall off over time, affecting long-term stability and resulting in poor reliability.

[0057] In this embodiment, the second terminal of the thermistor NTC is connected to the voltage divider resistor R1 to form a voltage sampling circuit 500 by connecting the thermistor NTC and the voltage divider resistor R1 in series. The first terminal of the thermistor NTC is directly surface-mounted to the source pad of the power transistor Q, thus connecting the first terminal of the series connection between the thermistor NTC and the voltage divider resistor R1 to the source of the power transistor Q. This eliminates the need for screws or adhesive, simplifying operation, reducing costs, and significantly simplifying production and installation. Furthermore, it provides better temperature detection accuracy, higher reliability, and greater convenience. Additionally, since the first terminal of the thermistor NTC in the voltage sampling circuit 500 is directly surface-mounted to the source of the power transistor Q, the sampling accuracy of temperature detection is further improved, enhancing the reliability of temperature detection.

[0058] In one exemplary embodiment, reference Figure 1 as well as Figures 10 to 12 As shown, a temperature detection circuit is provided for detecting the temperature of power transistor Q. In this embodiment, the isolated power supply circuit 200 is used to isolate the voltage provided by the power supply 300 through a transformer before providing it to the voltage sampling circuit 500. The isolated power supply circuit 200 can be an isolated DC / DC power supply circuit without a feedback sampling circuit, such as... Figure 10 As shown, it can also be an isolated DC power supply circuit with feedback sampling circuitry, such as... Figure 11 As shown, this application does not limit this.

[0059] For example, refer to Figure 10As shown, the isolated power supply circuit 200 is an isolated DC power supply circuit without feedback sampling circuitry. It can be composed of a chip, a transformer, and a diode rectifier. When the input is +5V, if the transformer is designed with a 1:1 turns ratio, its output is also +5V. The power supply 300 can supply power to the isolated power supply circuit 200 through its VIN and GND pins. The positive and negative terminals (VO+ and VO-) of the output of the isolated power supply circuit 200 are used to connect to the second and first terminals of the thermistor NTC and the voltage divider resistor R1 connected in series, respectively.

[0060] For example, refer to Figure 11 As shown, the isolated power supply circuit 200 is an isolated DC power supply circuit with a feedback sampling circuit. The difference between this example and the isolated DC power supply circuit without a feedback sampling circuit described above is that this example also includes an output sampling circuit 202 and a pulse modulation unit 201. The basic principle of isolated power supply in the isolated DC power supply circuit with and without a feedback sampling circuit is the same. However, because the isolated DC power supply circuit with a feedback sampling circuit adds an output sampling circuit 202 and a pulse modulation unit 201, the output of the isolated DC power supply circuit can be adjusted based on the output sampling, thereby improving the accuracy of the isolated power supply adjustment.

[0061] It should be noted that, in addition to the aforementioned isolated DC power supply circuit, the isolated power supply circuit 200 can also use various forward, flyback, resonant, and other transformer-isolated power supply circuits. This application does not limit this.

[0062] In addition, in this embodiment, the isolation sampling circuit 100 may include an isolation sampling chip, an isolation amplifier, or other forms of isolation sampling circuit 100, and there is no limitation on this.

[0063] It should be noted that the reference Figure 12 As shown, the isolation sampling circuit 100 may include an isolation sampling chip, whose output terminal (i.e., ADC pin) is connected to the control module 400, and the two input terminals (i.e., INP pin and INN pin) of the isolation sampling circuit 100 are respectively connected to the two ends of the thermistor NTC, thereby realizing isolated sampling.

[0064] In this embodiment, an independent power supply circuit 200 provides power to the voltage sampling circuit 500, creating a floating power supply loop that is not connected to the control module 400. This completely solves the sampling power supply problem caused by the floating source of the switching transistor Q1 on the bridge arm in full-bridge and half-bridge circuits. Simultaneously, the isolated power supply circuit 200 supports multiple topology options, adapting to different voltage and power consumption requirements. Combined with the multiple implementation schemes of the isolated sampling circuit 100, the entire temperature detection circuit can cover floating / grounded power transistors Q1 and power transistors Q1 in various topologies, significantly expanding the applicability of temperature detection. Furthermore, the isolated sampling circuit 100 can use an isolated sampling chip or an isolated amplifier, and each module can be flexibly combined according to the accuracy requirements, cost budget, and power consumption indicators of the actual scenario. Moreover, the core modules of this temperature detection circuit all use mature standardized components, eliminating the need for complex customized circuit designs. The overall architecture is simple and compact, allowing direct integration into the control board of existing power electronic systems without significant modifications to the original system structure, thus balancing detection performance and economy.

[0065] In one exemplary embodiment, reference Figures 1 to 5 As shown, a temperature detection circuit is provided for detecting the temperature of a power transistor Q. The power transistor Q can be a switching transistor in a full-bridge or half-bridge circuit. In this embodiment, the first terminal of a thermistor NTC is directly surface-mount soldered to the source pad of the power transistor Q. The second terminal of the thermistor NTC is connected to the first terminal of a voltage divider, thus forming a series connection between the thermistor NTC and the voltage divider resistor R1. The input terminal of the isolation power supply circuit 200 is connected to the power supply 300. The positive and negative terminals of the output terminals of the isolation power supply circuit 200 are connected to the first terminal of the thermistor NTC and the second terminal of the voltage divider resistor R1, respectively. The power supply terminal of the control module 400 is connected to the power supply 300. The control module 400 can be, for example, a microcontroller unit (MCU). The input terminal of the control module 400 is connected to the output terminal of the isolation sampling circuit 100. The two sampling input terminals of the isolation sampling circuit 100 are connected to the two ends of the thermistor NTC, respectively.

[0066] In this temperature detection circuit, since the first terminal of the thermistor NTC in the voltage sampling circuit 500 is directly connected to the source pad of the power transistor Q via surface mount soldering, when the temperature of the power transistor Q changes, it can more directly affect the thermistor NTC. Compared with the thermistor circuit connected to the heat sink in related technologies, the solution of this embodiment can improve the sampling accuracy and reliability of temperature detection.

[0067] Furthermore, because this embodiment employs isolated power supply and isolated sampling, it can sample the temperature of power transistor Q at any location without distinguishing between the floating ground or common ground of power transistor Q and control module 400, and can further improve the reliability of temperature detection. For example, for a full-bridge or half-bridge circuit, this temperature detection circuit can sample the temperature of not only the lower switch Q2 of the bridge arm but also the upper switch Q1 of the bridge arm.

[0068] When the power transistor Q is the upper switching transistor Q1 of the bridge arm of the full-bridge circuit, the first terminal of the thermistor NTC of the temperature detection circuit is surface-mounted to the source pad of the upper switching transistor Q1 of the bridge arm of the full-bridge circuit. The control module 400 in the temperature detection circuit can share a common ground with the lower switching transistor Q2 of the bridge arm of the full-bridge circuit, or it can not share a common ground with the lower switching transistor Q2. There is no limitation on this.

[0069] This embodiment considers the compatibility and versatility of the upper switching transistor Q1 and the lower switching transistor Q2 in a full-bridge or half-bridge circuit. Since the source of the upper switching transistor Q1 is a floating point, an independent isolated power supply (commonly 5V or 3.3V) is added. The temperature detection circuit uses a thermistor NTC surface-mount soldered to the source pad of the power transistor Q, along with isolated power supply and isolated sampling. When the temperature of the power transistor Q changes, the resistance of the thermistor NTC changes, and the voltage divider signal on the thermistor NTC also changes. This signal is then isolated and collected by the isolated sampling circuit 100 and sent to the control module 400 to complete the temperature sampling. This embodiment's temperature detection circuit can better improve the accuracy and reliability of temperature detection and has stronger versatility, solving the problem that the power transistor Q under test and the control module 400 are not grounded and therefore cannot be directly sampled.

[0070] In one exemplary embodiment, an energy storage power supply is provided. The energy storage power supply may include an energy storage unit, a power conversion circuit, and a temperature detection circuit as described in any of the above embodiments. The temperature detection circuit is used to detect the temperature of the power transistor in the power conversion circuit to improve the accuracy, reliability, and versatility of temperature detection.

[0071] In one exemplary embodiment, a power conversion device is provided. The power conversion device includes a power conversion circuit and a temperature detection circuit according to any of the above embodiments. The temperature detection circuit is used to detect the temperature of the power transistor in the power conversion circuit, thereby improving the accuracy, reliability, and versatility of temperature detection.

[0072] It should be understood that the terminology used herein is for the purpose of describing particular exemplary embodiments only and is not intended to be limiting. Unless the context clearly indicates otherwise, the singular forms “a,” “an,” and “described” as used herein may also include the plural forms. The terms “comprising,” “including,” “containing,” and “having” are inclusive and therefore indicate the presence of the stated features, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or combinations thereof. The method steps, processes, and operations described herein are not construed as requiring them to be performed in a particular order described or illustrated unless the order of performance is explicitly indicated. It should also be understood that additional or alternative steps may be used.

[0073] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0074] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A temperature detection circuit for a power transistor, used to detect the temperature of the power transistor, characterized in that, The temperature detection circuit includes a voltage sampling circuit, an isolated sampling circuit, an isolated power supply circuit, a power supply, and a control module. The voltage sampling circuit includes a thermistor and a voltage divider resistor connected in series, and the first terminal of the voltage sampling circuit is used to connect to the source of the power transistor. The input terminal of the isolated power supply circuit is connected to the power supply, and the positive and negative terminals of the output terminal of the isolated power supply circuit are connected to the second terminal and the first terminal of the voltage sampling circuit, respectively. The power supply terminal of the control module is connected to the power supply, and the input terminal of the control module is connected to the output terminal of the isolated sampling circuit. The two sampling input terminals of the isolated sampling circuit are connected to the two ends of the thermistor, respectively.

2. The temperature detection circuit according to claim 1, characterized in that, The power transistors include the upper or lower switching transistors of the bridge arms in a full-bridge or half-bridge circuit, or the main power transistors in a boost / buck circuit.

3. The temperature detection circuit according to claim 1, characterized in that, The control module and the source of the power transistor are not grounded together.

4. The temperature detection circuit according to claim 3, characterized in that, The source of the power transistor is connected to a first reference ground, and the ground terminal of the control module is connected to a second reference ground.

5. The temperature detection circuit according to claim 3, characterized in that, The power transistor is the upper switching transistor of the bridge arm in a full-bridge or half-bridge circuit. The source of the power transistor is grounded through the lower switching transistor, and the grounding terminal of the control module is grounded.

6. The temperature detection circuit according to claim 1, characterized in that, The first end of the thermistor forms the first end of the voltage sampling circuit. The first end of the thermistor is surface-mount soldered to the source pad of the power transistor. The second end of the thermistor is connected to the voltage divider resistor to realize the series connection of the thermistor and the voltage divider resistor.

7. The temperature detection circuit according to any one of claims 1-6, characterized in that, The isolated power supply circuit includes an isolated DC power supply circuit without a feedback sampling circuit or an isolated DC power supply circuit with a feedback sampling circuit.

8. The temperature detection circuit according to any one of claims 1-6, characterized in that, The isolation sampling circuit includes an isolation sampling chip and / or an isolation amplifier.

9. An energy storage power source, characterized in that, The energy storage power supply includes an energy storage unit, a power conversion circuit, and a temperature detection circuit as described in any one of claims 1-8, wherein the temperature detection circuit is used to detect the temperature of the power transistor in the power conversion circuit.

10. A power conversion device, characterized in that, The power conversion device includes a power conversion circuit and a temperature detection circuit as described in any one of claims 1-8, wherein the temperature detection circuit is used to detect the temperature of the power transistor in the power conversion circuit.

Images