Drive circuit, inverter apparatus, and vehicle

Abstract

A drive circuit (300), an inverter device (2) applying the drive circuit (300), and a vehicle including the inverter device (2), the drive circuit (300) including a gate driver (320), a bootstrap circuit (340), and a voltage detection and control device (360) connected between a positive terminal (Vcbs +) and a negative terminal (Vcbs-) of a bootstrap capacitor (Cbs) in the bootstrap circuit (340), and a control circuit for detecting a floating voltage of the bootstrap capacitor (Cbs) and controlling an operation of the gate driver (320) according to the detected floating voltage. The driving circuit (300) can detect the floating voltage of the bootstrap capacitor and correspondingly control the gate driver so as to avoid damage to the MOSFET / IGBT serving as a high-side switch or a low-side switch of the power inverter.

Description

Technical Field

[0001] The present invention relates to a driving circuit, an inverter device applying the circuit, and a vehicle including the inverter device, and more particularly to a driving circuit capable of detecting a floating voltage of a bootstrap capacitor to perform corresponding control on a gate driver, an inverter device applying the driving circuit, and a vehicle including the inverter device. Background Art

[0002] In the prior art, in order to supply a driving signal to an inductive load for electronic products such as electric vehicles, a power inverter that converts a direct current (DC) voltage into an alternating current (AC) voltage is usually used, and a gate driver for the power inverter is also required. Here, the inductive load may include an electric motor, a heating coil, etc.

[0003] An inverter device in the prior art generally includes a power inverter and a driving circuit. The power inverter generally includes a high-side switch and a low-side switch to generate an AC voltage. The high-side switch and the low-side switch are complementary-converted in each phase, and an insulated gate bipolar transistor (IGBT) or a metal-oxide-semiconductor field effect transistor (MOSFET) is usually adopted. The driving circuit generally includes a gate driver and a bootstrap circuit. The gate driver includes a high-side driver for driving the high-side switch of the power inverter and a low-side driver for driving the low-side switch of the power inverter. The bootstrap circuit includes a bootstrap capacitor, and the bootstrap capacitor is connected to the gate driver. Among them, since the voltage of the bootstrap capacitor is floating compared with the common ground, it is very difficult to detect the voltage of the bootstrap capacitor.

[0004] Therefore, there is a need for a driving circuit capable of detecting the floating voltage of a bootstrap capacitor to perform corresponding control on a gate driver and avoiding overvoltage of the bootstrap capacitor, and an inverter device including the driving circuit. Summary of the Invention

[0005] An object of the present invention is to provide an improved driving circuit without an isolator, which can detect the floating voltage of a bootstrap capacitor and perform corresponding control on a gate driver to avoid damage to MOSFET / IGBT serving as a high-side switch or a low-side switch of a power inverter.

[0006] Another object of the present invention is to provide an improved driving circuit without an isolator, which can convert the floating voltage of a bootstrap capacitor into a fixed voltage of a reference ground (GND) to avoid overvoltage of the bootstrap capacitor.

[0007] Another object of the present invention is to provide an inverter device applying the improved driving circuit.

[0008] Another object of the present invention is to provide a vehicle including the inverter device.

[0009] According to an aspect of the present invention, there is provided a drive circuit including a gate driver and a bootstrap circuit, characterized in that the drive circuit further includes a voltage detection and control device connected between the positive and negative terminals of a bootstrap capacitor in the bootstrap circuit for detecting the floating voltage of the bootstrap capacitor and controlling the operation of the gate driver according to the detected floating voltage.

[0010] According to another aspect of the present invention, there is provided an inverter device including a power inverter and the above drive circuit, wherein the high-side switch pulse output terminal and the low-side switch pulse output terminal of the gate driver in the drive circuit are respectively connected to the high-side switch and the low-side switch of the power inverter, and the high-side switch and the low-side switch of the power inverter are connected to the drive output node of the drive circuit.

[0011] According to still another aspect of the present invention, there is provided a vehicle including the above inverter device and a motor, and the inverter device is used to provide an electrical signal to the motor.

[0012] Compared with the prior art, the drive circuit and the inverter device of the present invention achieve the following beneficial technical effects:

[0013] 1. The detection of the floating voltage of the bootstrap capacitor in the drive circuit and the corresponding control of the gate driver are realized, thereby avoiding the damage to the MOSFET / IGBT of the high-side switch or the low-side switch of the power inverter caused by the overvoltage of the bootstrap capacitor;

[0014] 2. By detecting the floating voltage of the bootstrap capacitor and performing corresponding control on the gate driver, an isolator can be omitted in the drive circuit.

[0015] 3. When the floating voltage of the bootstrap capacitor has an overvoltage, the relatively high-level voltage of the reference floating ground output by the voltage detection device can be converted into a relatively low-level fixed voltage of the reference GND to facilitate the corresponding control of the gate driver by the control device. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The following describes the specific embodiments of the present invention with reference to the drawings.

[0017] Figure 1 It is a block diagram of the structure of an inverter device in the prior art.

[0018] Figure 2 For Figure 1 the voltage waveform diagram of the bootstrap capacitor in the drive circuit shown in

[0019] Figure 3 A structural block diagram of an inverter device according to an embodiment of the present invention.

[0020] Figure 4 is Figure 3 A structural block diagram of the voltage detection and control device in the drive circuit shown in

[0021] Figure 5 is Figure 3 A specific circuit diagram of the voltage detection and control device and the voltage conversion device in the drive circuit shown in Detailed implementation manners

[0022] In the following, details are set forth to provide a more comprehensive explanation of the exemplary detailed implementation manners. However, it will be apparent to those skilled in the art that the detailed implementation manners can be practiced without these specific details. In other cases, well-known structures and devices are shown in block diagram form or in schematic views rather than in detail to avoid obscuring the implementation manners. Additionally, unless otherwise specifically stated, the features of the different detailed implementation manners described below can be combined with each other.

[0023] Furthermore, equivalent or similar elements or elements having equivalent or similar functions are denoted by equivalent or similar reference numerals in the following description. Since the same or functionally equivalent elements are given the same reference numerals in the drawings, the repeated description of the elements provided with the same reference numerals can be omitted. Therefore, the descriptions provided for the elements having the same or similar reference numerals are interchangeable.

[0024] It should be understood that when an element is referred to as being "connected" or "coupled" to another element, the element can be directly connected or coupled to the other element, or there can be intermediate elements. In contrast, when an element is referred to as being "directly connected" or "directly coupled" to another element, there are no intermediate elements. Other words used to describe the relationship between elements should be interpreted in a similar manner (e.g., "between" and "directly between", "adjacent" and "directly adjacent", etc.).

[0025] In the specific implementation manners described herein or shown in the drawings, any direct electrical connection or coupling (i.e., any connection or coupling without additional intermediate elements) can also be achieved by an indirect connection or coupling (i.e., a connection or coupling with one or more additional intermediate elements), and vice versa, as long as the general purpose of the connection or coupling, such as transmitting a certain signal or sending a certain information, is substantially maintained. The features of different implementation manners can be combined to form additional implementation manners. For example, unless otherwise stated, the variations or modifications described with respect to one of the specific implementation manners can also be applied to other specific implementation manners.

[0026] A power transistor (also known as a power switch or transistor switch) is a power semiconductor device that can be used to drive a load current. For example, the power transistor is made to "conduct" or "turn off" by activating and deactivating its gate terminal. Applying a positive input voltage signal across the gate and the emitter will keep the device in the "conducting" state, while making the input gate signal zero or slightly negative will cause it to "turn off". There are turn-on and turn-off processes for turning the power transistor on and off.

[0027] During the turn-on process, a gate driver can be used to supply (source) a gate current (i.e., turn-on current) to the gate of the power transistor in order to charge the gate to a sufficient voltage for turning the power transistor on.

[0028] Conversely, during the turn-off process, the gate driver is used to draw (sink) a gate current (i.e., turn-off current) from the gate of the power transistor to fully discharge the gate to turn the power transistor off.

[0029] The transistor can include an insulated gate bipolar transistor (IGBT) and a metal-oxide-semiconductor field-effect transistor (MOSFET) (e.g., Si MOSFET or SiC MOSFET). Although an IGBT can be used as an example in the following embodiments, it should be understood that an MOSFET can replace the IGBT and vice versa. In this case, in any of the examples described herein, when an MOSFET replaces an IGBT, the drain of the MOSFET can replace the collector of the IGBT, the source of the MOSFET can replace the emitter of the IGBT, and the drain-source voltage VDS of the MOSFET can replace the collector-emitter voltage VCE of the IGBT. Thus, any IGBT module can be replaced by an MOSFET module and vice versa.

[0030] The specific embodiments described in this specification belong to but are not limited to power semiconductor devices that can be used within a power converter or a power supply. Thus, in an embodiment, the power semiconductor device can be configured to respectively carry a load current to be provided to a load and / or provided by a power supply. For example, the semiconductor device can include one or more power semiconductor units such as an integrated diode unit and / or an integrated transistor unit. Such a diode unit and / or such a transistor unit can be integrated in a power semiconductor module.

[0031] A power semiconductor device including transistors appropriately connected to form a half-bridge is commonly used in the field of power electronics. For example, a half-bridge can be used to drive a motor or a switched-mode power supply.

[0032] For example, a multiphase inverter is configured to supply multiphase power to a multiphase load (such as a three-phase motor). For example, three-phase power includes three symmetric sine waves that are out of phase with each other by 120 electrical degrees. In a symmetric three-phase power supply system, three conductors each carry an alternating current (AC) having the same frequency and voltage amplitude with respect to a common reference but having a phase difference of one-third of a cycle. Due to the phase difference, the voltage on any conductor reaches its peak one-third of a cycle after one of the other conductors and one-third of a cycle before the remaining conductor. This phase delay provides a constant power transfer for a balanced linear load. This also makes it possible to generate a rotating magnetic field in the motor.

[0033] The three-phase inverter includes three inverter legs, one inverter leg for each of the three phases, and each inverter leg is connected in parallel to a direct current (DC) voltage source. Each inverter leg includes, for example, a pair of power transistors arranged in a half-bridge configuration for converting the DC voltage into an AC voltage. In other words, each inverter leg includes two complementary transistors connected in series (i.e., a transistor acting as a high-side switch and a transistor acting as a low-side switch), which conduct and turn off complementarily to drive the phase load. However, the multiphase inverter is not limited to three phases and may include two phases or more than three phases, with one inverter leg for each phase.

[0034] Figure 1 An inverter device 1 in the prior art is shown, which includes a power inverter 100 and a drive circuit 200. The power inverter 100 includes a switch array composed of a plurality of transistors arranged in complementary pairs (usually six transistors in three complementary pairs, Figure 1 only the transistors Q1 and Q4 forming a complementary pair are exemplarily shown in the figure). Each complementary pair constitutes an inverter leg for supplying a phase current to an inductive load M (such as a three-phase motor of an electric vehicle). Therefore, each inverter leg includes an upper transistor module (i.e., a high-side switch, Figure 1 Q1 shown in the figure) and a lower transistor module (i.e., a low-side switch, Figure 1 Q4 shown in the figure). Each transistor module includes an IGBT or a MOSFET. For the sake of simplicity, only one inverter leg (including a transistor Q1 constituting the high-side switch and a transistor Q4 constituting the low-side switch) in the power inverter 100 is shown in Figure 1 the figure. The power inverter 100 is also coupled to a DC power supply UBAT (such as a battery or a diode bridge rectifier) and is connected to the drive circuit 200.

[0035] The drive circuit 200 includes a gate driver 220 and a bootstrap circuit 240. The gate driver 220 includes a high-side driver for driving the high-side switch of the power inverter 100 and a low-side driver for driving the low-side switch of the power inverter 100. The bootstrap circuit 240 includes a series-connected bootstrap diode D bs and a bootstrap capacitor C bs . The positive electrode of the bootstrap diode D bs is connected to the power supply terminal VDD of the gate driver 220 and the external power supply VCC, and the negative electrode is connected to the positive terminal Vcbs+ of the bootstrap capacitor C bs . The positive terminal Vcbs+ of the bootstrap capacitor C bs is also connected to the power supply terminal VB of the high-side switch drive output circuit of the gate driver 220, the negative terminal Vcbs- is connected to the power supply terminal VS of the low-side switch drive output circuit of the gate driver 220, and the power supply terminal VS of the low-side switch drive output circuit of the gate driver 220 is connected to the drive output node A. The drive output node A is connected between the high-side switch Q1 and the low-side switch Q4 of the power inverter 100 and is connected to the inductive load M. The high-side switch pulse output terminal HO and the low-side switch pulse output terminal LO of the gate driver 220 are respectively connected to the high-side switch Q1 and the low-side switch Q4 of the power inverter 100. The high-side switch Q1 and the low-side switch Q4 of the power inverter 100 are connected to the inductive load M through the drive output node A.

[0036] In some special cases, including but not limited to: the case where the DC power supply UBAT is accidentally disconnected while the motor serving as the inductive load M rotates at high speed; the case where the power supply VCC of the gate driver 220 loses power; the case of oscillation (overshoot or undershoot) caused by the conduction / turn-off of the IGBT / MOSFET serving as the high-side switch or the low-side switch of the power inverter 100; the case where the internal power supply of the gate driver 220 is unstable or fails, etc., the bootstrap capacitor C bs may generate overvoltage, which will cause a sudden change in the gate-to-source voltage Vgs of the MOSFET serving as the high-side switch or the low-side switch of the power inverter 100 or the base-to-emitter voltage Vge of the IGBT serving as the high-side switch or the low-side switch of the power inverter 100, resulting in failure, and causing the three-phase motor serving as the inductive load M to generate unexpected torque.

[0037] In the drive circuit of an inverter device in the prior art, voltage pulses can be output from a gate driver as a control signal according to a pulse width modulation (PWM) scheme. Therefore, during a PWM cycle for controlling a high-side switch and a low-side switch in a power inverter, the control signal is switched between a conduction voltage level and a turn-off voltage level, which in turn charges and discharges the gate voltage of the high-side switch or the low-side switch of the power inverter to turn on and turn off the high-side switch or the low-side switch of the power inverter, respectively.

[0038] As Figure 2 shown, when the high-side switch in the power inverter is turned on, the voltage V bs at the positive terminal Vcbs+ of the bootstrap capacitor C B is the UBAT voltage + VCC voltage referenced to the common ground (GND); when the low-side switch in the power inverter is turned on, the voltage V bs at the positive terminal Vcbs+ of the bootstrap capacitor C B is the VCC voltage referenced to the common ground (GND). Since when PWM is in the on (PWM_ON) or off (PWM_OFF) state, the voltage V bs at the positive terminal Vcbs+ of the bootstrap capacitor C B is floating compared to the common ground (GND), this makes it very difficult to detect the voltage V bs at the positive terminal Vcbs+ of the bootstrap capacitor C B .

[0039] Figure 3 FIG. shows an inverter device 2 according to an embodiment of the present invention, which includes a drive circuit 300 without an isolator and a power inverter 100. The power inverter 100 includes a switch array of a plurality of transistors arranged in complementary pairs (six transistors in three complementary pairs in this embodiment, Figure 3 only the transistors Q1 and Q4 forming a complementary pair are exemplarily shown), and each complementary pair constitutes an inverter branch for supplying a phase current to an inductive load M (a three-phase motor of an electric vehicle in this embodiment). For simplicity, in Figure 3 only one inverter branch in the power inverter 100 connected to the drive circuit 300 is shown, which includes a transistor Q1 constituting a high-side switch and a transistor Q4 constituting a low-side switch. The power inverter 100 is coupled to a DC power supply UBAT (such as a battery or a diode bridge rectifier) and is connected to the drive circuit 300, and its high-side switch Q1 and low-side switch Q4 are connected to a drive output node A connected to the inductive load M.

[0040] As Figure 3 shown, the drive circuit 300 includes a gate driver 320, a bootstrap circuit 340, a voltage detection and control device 360, and a voltage conversion device 380.

[0041] The high-side switch pulse output terminal HO and the low-side switch pulse output terminal LO of the gate driver 320 are respectively connected to the high-side switch Q1 and the low-side switch Q4 of the power inverter 100.

[0042] The bootstrap circuit 340 includes a series-connected bootstrap diode D bs and a bootstrap capacitor C bs , the positive electrode of the bootstrap diode D bs is connected to the power supply terminal VDD of the gate driver 320 and the external power supply VCC, and its negative electrode is connected to the positive terminal Vcbs+ of the bootstrap capacitor C bs . The positive terminal Vcbs+ of the bootstrap capacitor C bs is also connected to the power supply terminal VB of the high-side switch drive output circuit of the gate driver 320, its negative terminal Vcbs- is connected to the power supply terminal VS of the low-side switch drive output circuit of the gate driver 320, and the power supply terminal VS of the low-side switch drive output circuit of the gate driver 320 is connected to the drive output node A, and the drive output node A is connected to the inductive load M (in this embodiment, it is a three-phase motor of an electric vehicle).

[0043] The voltage detection and control device 360 is connected between the positive terminal Vcbs+ and the negative terminal Vcbs- of the bootstrap capacitor C bs and is connected to the input terminal or enable terminal of the gate driver 320 (in this embodiment, it is the input terminals HIN and LIN of the gate driver 320) and the external power supply VCC, and is used to detect the floating voltage of the bootstrap capacitor C bs and control the operation of the gate driver 320 according to the detected floating voltage.

[0044] The voltage conversion device 380 is connected between the voltage detection and control device 360 and the ground (GND), and is used to convert the first voltage (which can be 10V - 20V in this embodiment) of the reference drive output node A output by the voltage detection and control device 360 into a second voltage (which can be 5V in this embodiment) of the reference ground (GND), and the first voltage is higher than the second voltage. Since the drive output node (A) is a floating ground and the reference ground (GND) is a fixed ground, the first voltage is a floating voltage and the second voltage is a fixed voltage. The voltage conversion device 380 plays a dual role of step-down (to match the working voltage of the control device 360) and converting the floating voltage into a fixed voltage.

[0045] Of course, according to the specific requirements of different application scenarios, in a variant of this embodiment, the drive circuit may not include a voltage conversion device.

[0046] Figure 4 For Figure 3Block diagram of the voltage detection and control device 360 in the driving circuit 300 shown.

[0047] As Figure 4 shown, the voltage detection and control device 360 includes a voltage detection device 3602 and a control device 3604.

[0048] The voltage detection device 3602 is connected between the positive terminal Vcbs+ and the negative terminal Vcbs- of the bootstrap capacitor C bs and is connected to the voltage conversion device 380, and is used to detect the floating voltage of the bootstrap capacitor C bs and when an overvoltage occurs in the bootstrap capacitor C bs , output the first voltage referring to the drive output node A to the voltage conversion device 380.

[0049] The control device 3604 is connected to the voltage conversion device 380 and is connected to the input terminal or the enable terminal of the gate driver 320, and is used to receive the second voltage referring to the reference ground (GND) output by the voltage conversion device 380, and accordingly control the operation of the gate driver 320.

[0050] Of course, those skilled in the art can understand that based on the specific requirements in different application scenarios, the control device 3604 can also be connected to other input terminals or enable terminals of the gate driver 320, and when the bootstrap capacitor C bs is in an overvoltage condition, output a shutdown signal to shut down the corresponding input terminal or enable terminal of the gate driver 320.

[0051] Figure 5 For Figure 3 the specific circuit diagram of the voltage detection and control device 360 and the voltage conversion device 380 in the driving circuit 300 shown.

[0052] As Figure 5 shown, the voltage detection device 3602 in the voltage detection and control device 360 includes a comparator 3602A, an anti-mis-trigger diode 3602B, a logic control transistor 3602C, and a first Zener diode 3602D.

[0053] The comparator 3602A is a general-purpose comparator, its power supply pin Vcc is connected to the positive terminal Vcbs+ of the bootstrap capacitor Cbs and the external power supply VCC, its power supply pin Vee is connected to the negative terminal Vcbs- of the bootstrap capacitor Cbs and the positive terminal of the first Zener diode 3602D and is connected to the drive output node A (i.e. Figure 5The point A shown in [figure]; its positive input pin is connected to the positive terminal Vcbs+ of the bootstrap capacitor Cbs and the external power supply VCC through the resistor R2 and is connected to the negative terminal Vcbs- of the bootstrap capacitor Cbs and the positive terminal of the first Zener diode 3602D through the resistor R4; its negative input pin is connected to the negative terminal of the first Zener diode 3602D and is connected to the positive terminal Vcbs+ of the bootstrap capacitor Cbs through the resistor R1; a filter capacitor C1 is connected between its positive input pin and negative input pin; its output pin S1 is connected to the positive terminal Vcbs+ of the bootstrap capacitor Cbs through the resistor R5 and is connected to the positive terminal of the anti-mis-trigger diode 3602B. The comparator 3602A is used to receive the floating voltage of the bootstrap capacitor Cbs, compare the divided voltage obtained by dividing the VCC voltage of the external power supply VCC through the resistors R2 and R4 with the voltage at the negative terminal of the Zener diode 3602D, and output a first voltage for driving the output node A. If the divided voltage is higher than the voltage at the negative terminal of the Zener diode 3602D, it indicates that an overvoltage has occurred in the bootstrap capacitor Cbs, and the first voltage (approximately equal to the UBAT voltage + VCC voltage or the UBAT voltage + V cbs voltage, which can be 10V - 20V in this embodiment) is higher than the gate voltage of the logic control transistor 3602C, and the logic control transistor 3602C conducts to output the first voltage to the voltage conversion device 380, and then the control device 3604 performs an operation of controlling the gate driver 320 according to the voltage signal received from the voltage conversion device 380. If the divided voltage is equal to or lower than the voltage at the negative terminal of the Zener diode 3602D, it indicates that no overvoltage has occurred in the bootstrap capacitor Cbs, the first voltage for driving the output node A output by the comparator 3602A is lower than the gate voltage of the logic control transistor 3602C, and the logic control transistor 3602C turns off, so that no voltage signal is transmitted to the voltage conversion device 380, and the control device 3604 has no voltage signal input from the voltage conversion device 380, and thus does not need to perform an operation of controlling the gate driver 320. The resistance values of the resistors R2 and R4 can be set according to the threshold for determining an overvoltage in the bootstrap capacitor Cbs.

[0054] The positive terminal of the anti-mis-trigger diode 3602B is connected to the output pin S1 of the comparator 3602A, and its negative terminal is connected to the source of the logic control transistor 3602C, and is used to prevent the output signal of the output pin S1 of the comparator 3602A from causing the logic control transistor 3602C to be mis-triggered and conduct.

[0055] The source of the logic control transistor 3602C is connected to the negative terminal of the anti-mis-trigger diode 3602B. Its gate is connected to the negative terminal Vcbs- of the bootstrap capacitor Cbs and the drive output node A through the resistor R6, and its drain is connected to the voltage conversion device 380. When the logic control transistor 3602C is turned on, it outputs the first voltage (which can be 10V - 20V in this embodiment) output by the comparator 3602A with reference to the drive output node A to the voltage conversion device 380.

[0056] The first Zener diode 3602D is used to clamp the input pin of the comparator 3602A to a stable voltage. Its positive terminal is connected to the negative terminal Vcbs- of the bootstrap capacitor C (which is connected to the drive output node A, that is, the source of the high-side switch Q1 of the power inverter 100 coupled to the DC power supply UBAT) and the power supply pin Vee of the comparator 3602A; its negative terminal is connected to the negative input pin of the comparator 3602A and is connected to the positive terminal Vcbs+ of the bootstrap capacitor C through the resistor R1; and a resistor R3 is connected between its positive terminal and negative terminal. bs The negative terminal Vcbs- of the bootstrap capacitor C and the power supply pin Vee of the comparator 3602A; its negative terminal is connected to the negative input pin of the comparator 3602A and is connected to the positive terminal Vcbs+ of the bootstrap capacitor C through the resistor R1; and a resistor R3 is connected between its positive terminal and negative terminal. bs The positive terminal Vcbs+ of the bootstrap capacitor C; and a resistor R3 is connected between its positive terminal and negative terminal.

[0057] The control device 3604 in the voltage detection and control device 360 can adopt a microcontroller unit (MCU), which is respectively connected to the input ends or enable ends (in this embodiment, they are the input ends HIN and LIN) of the voltage conversion device 380 and the gate driver 320, and is used to receive the high-level voltage (UBAT voltage + VCC voltage or UBAT voltage + V voltage, which can be 10V - 20V in this embodiment) relative to the drive output node A output by the voltage conversion device 380 when the logic control transistor 3602C is turned on and convert it into a fixed voltage (such as 3V - 5V in this embodiment) with reference to GND, and accordingly output a turn-off signal to turn off the input ends or enable ends (in this embodiment, they are the input ends HIN and LIN of the gate driver 320) of the gate driver 320. cbs The voltage relative to the drive output node A output by the voltage conversion device 380 when the logic control transistor 3602C is turned on (which can be 10V - 20V in this embodiment) and convert it into a fixed voltage (such as 3V - 5V in this embodiment) with reference to GND, and accordingly output a turn-off signal to turn off the input ends or enable ends (in this embodiment, they are the input ends HIN and LIN of the gate driver 320) of the gate driver 320.

[0058] Such as Figure 5As shown, the voltage conversion device 380 is used to convert the first voltage (which can be 10V - 20V in this embodiment) of the reference drive output node A output by the conduction of the logic control transistor 3602C into the second voltage (which can be 3V - 5V) of the reference GND, and output it to the control device 3604, so that the control device 3604 outputs a turn-off signal to turn off the input terminal or the enable terminal of the gate driver 320. The voltage conversion device 380 includes a second Zener diode 380A, a pull-down resistor R7, and a voltage-dividing resistor R8. One end of the pull-down resistor R7 is connected to the drain of the logic control transistor 3602C and one end of the voltage-dividing resistor R8, and the other end is connected to the ground GND, and is used to pull down the first voltage output by the conduction of the logic control transistor 3602C in a voltage-dividing manner. The positive terminal of the second Zener diode 380A is grounded (GND), and the negative terminal is connected to the other end of the voltage-dividing resistor R8 and the control device (MCU) 3604, and is used to clamp the voltage after the voltage across the pull-down resistor R7 (which has been converted to the reference ground GND) is divided by the voltage-dividing resistor R8 to the fixed voltage of the low level of the reference GND required by the control device (MCU) 3604 (i.e., the second voltage). The voltage-dividing resistor R8 is used to bear the difference voltage between the voltage across the pull-down resistor R7 and the voltage across the two ends of the second Zener diode 380A in a voltage-dividing manner.

[0059] As Figure 5 shown, the voltage detection and control device 360 includes several resistors (R1 - R6) and a capacitor (C1). Those skilled in the art clearly understand the functions of these resistors and capacitors, and understand that different numbers of resistors and capacitors, as well as different connection methods, can be adopted according to specific application scenarios. Therefore, the number and connection method of the resistors and capacitors adopted in this embodiment do not limit the protection scope of the present invention.

[0060] In the embodiment of the present invention, the overvoltage at both ends of the bootstrap capacitor C bs is taken as an example for illustration, but it can be understood that by adaptively adjusting the circuit logic using the method of the embodiment of the present invention, it is also possible to detect the undervoltage at both ends of the bootstrap capacitor C bs and perform corresponding control on the gate driver to protect the inverter device.

[0061] The inverter device in the embodiment of the present invention can be used for a motor, and the motor can be a motor of a vehicle such as a four-wheeled vehicle, a two-wheeled vehicle, or a three-wheeled vehicle. The inverter device and the motor can be integrated together or separately arranged on the vehicle.

[0062] The present invention also provides a vehicle (not shown), which includes the inverter device and the motor described in the embodiment of the present invention, and the inverter device is used to provide an electrical signal to the motor.

[0063] Although various specific embodiments have been described, it will be apparent to those of ordinary skill in the art that the invention is not limited except as to the appended claims and their equivalents. With respect to the various functions performed by the above-described components or structures (components, devices, circuits, etc.), unless otherwise indicated, the terms used to describe such components (including references to "means"), even if not structurally equivalent to the disclosed structures performing the functions in the exemplary specific embodiments of the invention shown herein, are intended to correspond to any component or structure that performs the specified function of the described component (i.e., functionally equivalent).

[0064] In addition, the appended claims are hereby incorporated into the detailed description, where each claim may stand on its own as a separate exemplary embodiment. Although each claim may stand on its own as a separate exemplary embodiment, it should be noted that, even though a dependent claim may refer in the claim to a specific combination with one or more other claims, other exemplary embodiments may also include a combination of the subject matter of the dependent claim with each other dependent claim or independent claim. Such combinations are presented herein unless stated otherwise not to be intended. In addition, even if the claim does not directly refer to an independent claim, the features of the claim are intended to be included in any other independent claim.

Claims

1. A driving circuit (300) includes a gate driver (320) and a bootstrap circuit (340), characterized in that, The driving circuit (300) further includes a voltage detection and control device (360), which is connected between the positive terminal (Vcbs+) and the negative terminal (Vcbs-) of the boost capacitor (C bs ) in the boost circuit (340) for detecting the floating voltage of the boost capacitor (C bs ) and controlling the operation of the gate driver (320) according to the detected floating voltage.

2. The drive circuit according to claim 1, characterized in that, The bootstrap circuit (340) includes a series-connected bootstrap diode (D bs ), and the bootstrap capacitor (C bs ). The anode of the bootstrap diode (D bs ) is connected to the power supply terminal (VDD) of the gate driver (320) and the external power supply (VCC), and its cathode is connected to the positive terminal (Vcbs+) of the bootstrap capacitor (C bs ). The positive terminal (Vcbs+) of the bootstrap capacitor (C bs ) is also connected to the power supply terminal (VB) of the high-side switch driving output circuit of the gate driver (320), and its negative terminal (Vcbs-) is connected to the power supply terminal (VS) of the low-side switch driving output circuit of the gate driver (320). Moreover, the power supply terminal (VS) of the low-side switch driving output circuit is also connected to the driving output node (A) connected to the load (M).

3. The drive circuit according to claim 1, wherein The driving circuit (300) further includes a voltage conversion device (380) connected between the voltage detection and control device (360) and the ground (GND) for converting a first voltage output by the voltage detection and control device (360) and referencing the driving output node (A) into a second voltage referencing the ground, where the first voltage is higher than the second voltage.

4. The drive circuit according to claim 3, wherein The voltage detection and control device (360) includes: A voltage detection device (3602), connected between the positive terminal (Vcbs+) and the negative terminal (Vcbs-) of the boost capacitor (C bs ) and connected to the voltage conversion device (380), is configured to detect the floating voltage of the boost capacitor (C bs ) and, when an overvoltage occurs in the boost capacitor (C bs ), output the first voltage referenced to the drive output node (A) to the voltage conversion device (380); and a control device (3604) connected to the voltage conversion device (380) and connected to the input terminal or the enable terminal of the gate driver (320) for receiving the second voltage referencing the ground output by the voltage conversion device (380) and controlling the operation of the gate driver (320) accordingly.

5. The drive circuit according to claim 4, wherein The voltage detection device (3602) includes a comparator (3602A) and a first Zener diode (3602D).

6. The drive circuit according to claim 5, wherein The comparator (3602A) is configured to receive the floating voltage of the boost capacitor (C bs ) and, when an overvoltage occurs in the boost capacitor (C bs ), output the first voltage that references the drive output node (A) to the voltage conversion device (380); and The first Zener diode (3602D) is used to clamp the input pin of the comparator (3602A) to a stable voltage.

7. The drive circuit according to claim 6, wherein The power supply pin (Vcc) of the comparator (3602A) is connected to the positive terminal (Vcbs+) of the bootstrap capacitor (Cbs), the external power supply (VCC), and the negative terminal (Vee) of the comparator (3602A) is connected to the negative terminal (Vcbs-) of the bootstrap capacitor (Cbs), the positive terminal of the first Zener diode (3602D), and the drive output node (A). Its positive input pin is connected to the positive terminal (Vcbs+) and the negative terminal (Vcbs-) of the bootstrap capacitor (C bs ), the external power supply (VCC), and the positive terminal of the first Zener diode (3602D). Its negative input pin is connected to the negative terminal of the first Zener diode (3602D) and the positive terminal (Vcbs+) of the bootstrap capacitor (C bs ), and its output pin is connected to the positive terminal of the bootstrap capacitor (C bs ) and the voltage conversion device (380).

8. The drive circuit according to claim 5, characterized in that The voltage detection device (3602) further includes a logic control transistor (3602C) disposed between the comparator (3602A) and the voltage conversion device (380), The source of the logic control transistor (3602C) is connected to the output terminal of the comparator (3602A), and its gate is connected to the negative terminal (Vcbs-) of the bootstrap capacitor (C bs ) and the drive output node (A), and its drain is connected to the voltage conversion device (380), wherein when the first voltage output by the comparator (3602A) and referencing the driving output node (A) is higher than the gate voltage of the logic control transistor (3602C), the logic control transistor (3602C) is turned on to output the first voltage to the voltage conversion device (380); when the first voltage output by the comparator (3602A) and referencing the driving output node (A) is lower than the gate voltage of the logic control transistor (3602C), the logic control transistor (3602C) is turned off.

9. The drive circuit according to claim 8, wherein The voltage detection device (3602) further includes an anti-mis-trigger diode (3602B) disposed between the comparator (3602A) and the logic control transistor (3602C). The positive terminal of the anti-mis-trigger diode (3602B) is connected to the output pin (S1) of the comparator (3602A), and its negative terminal is connected to the source of the logic control transistor (3602C) for preventing the output signal of the output pin of the comparator (3602A) from causing the logic control transistor (3602C) to be mis-triggered and turned on.

10. The drive circuit according to claim 8 or 9, characterized in that, The voltage conversion device (380) includes a second Zener diode (380A), a pull-down resistor (R7), and a voltage-dividing resistor (R8), where one end of the pull-down resistor (R7) is connected to the drain of the logic control transistor (3602C) and one end of the resistor (R8), and the other end is connected to the ground (GND), the other end of the voltage-dividing resistor R8 is respectively connected to the control device (3604) and the negative terminal of the second Zener diode (380A), and the positive terminal of the second Zener diode (380A) is grounded (GND). The voltage conversion device (380) is configured to convert the first voltage output when the logic control transistor (3602C) is turned on into the second voltage with respect to the reference ground (GND), and output the converted voltage to the control device (3604), so that the control device (3604) outputs a turn-off signal to turn off the input terminal or the enable terminal of the gate driver (320).

11. An inverter device (2) comprising a power inverter (100) and a drive circuit (300) according to any one of claims 1 to 10, wherein, The high-side switch pulse output terminal (HO) and the low-side switch pulse output terminal (LO) of the gate driver (320) in the drive circuit (300) are respectively connected to the high-side switch and the low-side switch of the power inverter (100), and the high-side switch and the low-side switch of the power inverter are connected to the drive output node (A) of the drive circuit (300) that is connected to the load (M).

12. A vehicle, comprising the inverter device (2) according to claim 11 and an electric motor, wherein the inverter device (2) is configured to supply an electrical signal to the electric motor.

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