Drive circuit, inverter apparatus, and vehicle
By introducing floating voltage detection and control devices and anti-error triggering devices into the driving circuit, the problem of difficult detection of floating voltage of the bootstrap capacitor is solved, effective control of the gate driver is achieved, and MOSFET/IGBT damage in the inverter equipment is avoided.
Patent Information
- Application Number
- CN202311863370.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2023-12-29
- Publication Date
- 2025-07-01
AI Technical Summary
In the prior art, the floating voltage of the bootstrap capacitor is difficult to detect, resulting in the inability to effectively control the gate driver, which may damage the MOSFET/IGBT in the power inverter.
A driving circuit without an isolator is designed, including a floating voltage detection and control device and an anti-error triggering device, which can detect the floating voltage of the bootstrap capacitor and control the operation of the gate driver accordingly.
The detection and control of the floating voltage of the bootstrap capacitor is realized, which avoids damage to MOSFET/IGBT and improves the reliability of the inverter equipment.
Smart Images
Figure CN120237906A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a driving circuit, an inverter device applying the driving 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 and controlling an operation of a gate driver based thereon, 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 to an alternating current (AC) voltage is generally used, and a gate driver for driving the 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 generally used. 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 to the common ground, it is very difficult to detect the voltage of the bootstrap capacitor.
[0004] Therefore, a driving circuit and an inverter device applying the driving circuit that can detect and control the floating voltage of the bootstrap capacitor to avoid overvoltage of the bootstrap capacitor are desired. 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 control the operation of a gate driver based thereon, thereby avoiding damage to MOSFET / IGBT as the high-side switch or the low-side switch of a power inverter.
[0006] Another object of the present invention is to provide an inverter device applying the improved driving circuit.
[0007] Still another object of the present invention is to provide a vehicle including the inverter device.
[0008] According to a first aspect of the present invention, there is provided a driving circuit, including a gate driver and a bootstrap circuit including a bootstrap capacitor, characterized in that the driving circuit further includes: a floating voltage detection and control device for detecting the floating voltage of the bootstrap capacitor and controlling the operation of the gate driver accordingly; and an anti-mis-triggering device for preventing the floating voltage detection and control device from being mis-triggered, wherein the floating voltage detection and control device is connected between the positive and negative terminals of the bootstrap capacitor of the bootstrap circuit and is connected to the anti-mis-triggering device and the gate driver.
[0009] According to a second aspect of the present invention, there is provided an inverter device, including a power inverter and the above-mentioned driving circuit, wherein the high-side switch pulse output terminal and the low-side switch pulse output terminal of the gate driver in the driving 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 driving output node of the driving circuit connected to the load.
[0010] According to a third aspect of the present invention, there is provided a vehicle, including the above-mentioned inverter device and a motor, and the inverter device is used to provide an electrical signal to the motor.
[0011] Compared with the prior art, the driving circuit and the inverter device of the present invention achieve the following beneficial technical effects: realizing the detection of the floating voltage of the bootstrap capacitor in the driving circuit and the corresponding control of the gate driver, thereby avoiding the damage of MOSFET / IGBT serving as the high-side switch or the low-side switch of the power inverter. Description of the Drawings
[0012] The following describes the specific embodiments of the present invention with reference to the drawings.
[0013] Figure 1 It is a structural block diagram of an inverter device in the prior art.
[0014] Figure 2 It is Figure 1 the voltage waveform diagram of the bootstrap capacitor in the driving circuit shown in
[0015] Figure 3 It is a structural block diagram of an inverter device according to an embodiment of the present invention.
[0016] Figure 4 It is Figure 3 the structural block diagram of the floating voltage detection and control device in the driving circuit shown in
[0017] Figure 5 It is Figure 3The specific circuit diagrams of the floating voltage detection and control device and the anti-mis-triggering device in the drive circuit shown in [the figure]. Detailed implementation manners
[0018] 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.
[0019] 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.
[0020] 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.).
[0021] In the detailed 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 through 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 transmitting a certain information, is substantially maintained. The features of different detailed implementation manners can be combined to form additional detailed implementation manners. For example, unless otherwise stated, the variations or modifications described with respect to one of the detailed implementation manners can also be applied to other detailed implementation manners.
[0022] A power transistor (also referred to as a power switch or transistor switch) is a power semiconductor device that can be used to drive a load current. For example, it is made to be "on" or "off" by activating and deactivating the gate terminal of the power transistor. Applying a positive input voltage signal across the gate and the source will keep the device in the "on" state, while making the input gate signal zero or slightly negative will cause it to be "off". There are a turn-on process and a turn-off process for turning the power transistor on and off.
[0023] During the turn-on process, a gate driver can be used to supply a (source) gate current (i.e., turn-on current) to the gate of a power transistor in order to charge the gate to a sufficient voltage for turning on the power transistor.
[0024] Conversely, during the turn-off process, the gate driver is used to draw a (drain) gate current (i.e., turn-off current) from the gate of the power transistor to fully discharge the gate to turn off the device.
[0025] 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 one 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.
[0026] 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 carry a load current to be supplied to a load and / or supplied by a power supply, respectively. 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.
[0027] Power semiconductor devices including transistors appropriately connected to form a half-bridge are 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.
[0028] For example, a multiphase inverter is configured to provide multiphase power by supplying a multiphase load (e.g., 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 a motor.
[0029] A three-phase inverter includes three inverter legs, with 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 DC to AC. 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) that conduct and turn off complementary to each other to drive the phase load. However, a 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.
[0030] 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, 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 (e.g., 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 the transistor Q1 forming the high-side switch and the transistor Q4 forming 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 (e.g., a battery or a diode bridge rectifier) and is connected to the drive circuit 200.
[0031] 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.
[0032] In the drive circuit of an inverter device in the prior art, voltage pulses can be output from the gate driver as control signals according to a pulse width modulation (PWM) scheme. Therefore, during the PWM period for controlling the high-side switch and the low-side switch in the power inverter, the control signal is switched between the on-voltage level and the 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 off the high-side switch or the low-side switch of the power inverter respectively.
[0033] 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 the voltage V bs at the positive terminal Vcbs+ of the bootstrap capacitor C B is floating compared to the common ground (GND) when PWM is in the on (PWM_ON) or off (PWM_OFF) state, this makes it possible to charge and discharge the bootstrap capacitor Cbs The voltage V of the positive extreme Vcbs+ B is very difficult to detect.
[0034] Figure 3 Fig. 7 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 constituting 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 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.
[0035] As Figure 3 shown, the drive circuit 300 includes a gate driver 320, a bootstrap circuit 340, a floating voltage detection and control device 360, and an anti-mis-triggering device 380.
[0036] 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.
[0037] 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 an external power supply VCC, and the negative electrode is connected to the positive extreme Vcbs+ of the bootstrap capacitor C bs . The positive extreme 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 extreme 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.
[0038] The floating voltage detection and control device 360 is connected across the bootstrap capacitor C bsbetween the positive terminal Vcbs+ and the negative terminal Vcbs- of the boost capacitor C and is connected to the input terminal or the enable terminal of the anti-mis-triggering device 380 and the gate driver 320 (in this embodiment, the input terminals HIN and LIN of the gate driver 320), and is used to detect the floating voltage of the boost capacitor C bs and control the operation of the gate driver 320 according to the detected floating voltage.
[0039] The anti-mis-triggering device 380 is respectively connected to the input terminal or the output terminal of the floating voltage detection and control device 360 and the gate driver 320 (in this embodiment, the output terminal LO of the gate driver 320, or it can be the input terminal of the gate driver 320 such as LIN, etc.), and is used to prevent the floating voltage detection and control device 360 from being mis-triggered.
[0040] Figure 4 is Figure 3 the structural block diagram of the floating voltage detection and control device 360 in the drive circuit 300 shown in. As Figure 4 shown, the floating voltage detection and control device 360 includes a floating voltage detection device 3602 and a detection control device 3604
[0041] The floating voltage detection device 3602 is connected between the positive terminal Vcbs+ and the negative terminal Vcbs- of the boost capacitor C in the boost circuit 340, and is used to detect the floating voltage of the boost capacitor C bs and the negative terminal Vcbs-, and is used to detect the floating voltage of the boost capacitor C bs of.
[0042] The input terminal of the detection control device 3604 is connected to the output terminal of the floating voltage detection circuit 3602, its control terminal is connected to the anti-mis-triggering device 380 and its output terminal is connected to the input terminal or the enable terminal of the gate driver 320 (in this embodiment, the input terminals HIN and LIN of the gate driver 320), and is used to receive the floating voltage of the boost capacitor C output by the floating voltage detection device 3602 bs and control the operation of the gate driver 320 accordingly, and is prevented from being mis-triggered through the anti-mis-triggering device 380.
[0043] Of course, those skilled in the art can understand that based on the specific requirements in different application scenarios, the detection control device 3604 can also be connected to other input terminals or enable terminals of the gate driver 320, and when the boost capacitor C bs is in an overvoltage situation, an off signal is output to turn off the corresponding input terminal or enable terminal of the gate driver 320.
[0044] Figure 5 is Figure 3 the specific circuit diagram of the floating voltage detection and control device 360 and the anti-mis-triggering device 380 in the drive circuit 300 shown in.
[0045] In this embodiment, the floating voltage detection device 3602 in the floating voltage detection and control device 360 is a differential sampling and subtraction circuit, which includes an operational amplifier S1 and a plurality of resistors R1 - R8 and a filter capacitor C1 connected thereto. The operational amplifier S1 is a general-purpose operational amplifier, whose power supply pin Vcc is connected to an external power supply ES1 (15V power supply in this embodiment); its power supply pin Vee is grounded; its positive input pin is connected to the positive terminal Vcbs+ of the bootstrap capacitor Cbs through the series-connected resistors R1 and R5, grounded (GND) through the series-connected resistors R3 and R5, and grounded (GND) through the resistor R7; its negative input pin is connected to the negative terminal Vcbs- of the bootstrap capacitor Cbs through the series-connected resistors R2 and R6, grounded (GND) through the series-connected resistors R4 and R6, and connected to its output pin through the resistor R8; a filter capacitor C1 is connected between its positive input pin and negative input pin; its output pin outputs the floating voltage of the obtained bootstrap capacitor Cbs. The positive input pin of the operational amplifier S1 receives the first divided voltage after dividing the positive terminal voltage Vcbs+ of the bootstrap capacitor C bs by the resistors R1 and R3, and its negative input pin receives the second divided voltage after dividing the negative terminal voltage Vcbs- of the bootstrap capacitor C bs by the resistors R2 and R4, performs a subtraction process on the two divided voltages, then amplifies the result after the subtraction process by the resistors R5 - R8, and outputs the amplified result (i.e., the floating voltage of the bootstrap capacitor Cbs) to the detection and control device 3604 through its output pin.
[0046] The detection and control device 3604 in the floating voltage detection and control device 360 includes a threshold comparison device 3604A, a control device 3604B, and a first transistor T2 and resistors R10, R11, and R17 connected thereto.
[0047] The threshold comparison device 3604A is connected to the output terminal of the floating voltage detection device (3602) and connected to the source electrode of the first transistor T2, and is used to receive the floating voltage of the bootstrap capacitor Cbs output by the floating voltage detection device 3602, and compare the floating voltage with a predetermined threshold voltage (18V in this embodiment) to output a first comparison signal.
[0048] The threshold comparison device 3604A includes a first comparator S2, a threshold voltage input device Vth1, a resistor R9, and a capacitor C2. The first comparator S2 is a general-purpose comparator. Its power supply pin Vcc is connected to an external power supply ES2 (which is a 15V power supply in this embodiment); its power supply pin Vee is grounded (GND). Its positive input pin is connected to the output pin of the floating voltage detection device 3602 and grounded (GND) through the capacitor C2; its negative input pin is connected to the threshold voltage input device Vth1 for providing the predetermined threshold voltage; its output pin is connected to the source of the first transistor T2 and connected to the external power supply ES3 (which is a 3.3V pull-up power supply in this embodiment) through the resistor R9. The first comparator S2 is used to receive the floating voltage of the bootstrap capacitor Cbs output by the floating voltage detection device 3602, and compare the floating voltage with the predetermined threshold voltage provided by the threshold voltage input device Vth1 to output the first comparison signal to the first transistor T2.
[0049] The source of the first transistor T2 is connected to the output pin of the first comparator S2. Its drain is connected to the control device 3604B and grounded through the resistor R17. Its gate is connected to the anti-mistrigger device 380 via the resistor R11, and a resistor R10 is connected between its source and gate. When the bs When in overvoltage, the voltage of the first comparison signal output by the first comparator S2 is higher than the gate voltage of the first transistor T2, and the first transistor T2 is turned on to transmit the first comparison signal output by the first comparator S2 to the control device 3604B.
[0050] The control device 3604B is a microcontroller unit (MCU), and is respectively connected to the drain of the first transistor T2 and the input terminals HIN and LIN of the gate driver 320 (as described above, based on different application scenarios, it can also be connected to other input terminals or enable terminals of the gate driver 320). When the bootstrap capacitor (Cbs) is in overvoltage, it is used to receive the first comparison signal from the first comparator S2 in the threshold comparison device 3604A transmitted after the first transistor T2 is turned on, and output a shutdown signal to shut down the input terminals HIN and LIN of the gate driver 320.
[0051] In this embodiment, the driving circuit 300 uses the input voltage pulse or output voltage pulse of the gate driver 320 as a control signal according to the pulse width modulation (PWM) scheme. In this application scenario, due to the oscillation and floating of the PWM on / off signal output by the gate driver 320 and the slew rate of the operational amplifier, the threshold comparison device 3604A in the floating voltage detection device 3602 and the detection control device 3604 may be accidentally triggered. Through testing, the circuit of the embodiment of the present invention effectively suppresses the influence of the oscillation of the PWM on / off signal and the slew rate by using the anti-mis-triggering device 380.
[0052] The anti-mis-triggering device 380 includes a phase shift device 380A and a logic gate control device 380B, which are used to prevent the threshold comparison device 3604A in the floating voltage detection device 3602 and the detection control device 3604 from being accidentally triggered.
[0053] The phase shift device 380A includes a phase shift resistor R12 and a phase shift capacitor C3. One end of the phase shift resistor R12 is connected to the input end or output end of the gate driver 320 (in this embodiment, it is the output end LO of the gate driver 320, or it can be the input end of the gate driver 320 such as LIN, etc.), and the other end is connected to one end of the phase shift capacitor C3 and the positive input pin of the logic gate control device 380B. The other end of the phase shift capacitor C3 is grounded (GND). The phase shift device 380A is used to shift the phase of the voltage pulse from the input end or output end of the gate driver 320 to output a phase-shifted voltage.
[0054] The logic gate control device 380B includes a reference voltage input device Vth2, a second comparator S3, a second transistor T1, a plurality of resistors R13 - R16, and a plurality of capacitors C4 - C5. The logic gate control device 380B is used to control the on / off timing of the second transistor T1 through the second comparator S3.
[0055] The second comparator S3 is a general-purpose comparator, which is used to compare the phase-shifted voltage output by the phase-shifting device 380A with a reference voltage provided by the reference voltage input device Vth2 and output a second comparison signal, and control the on and off of the second transistor T1 according to the second comparison signal. The power supply pin Vcc of the second comparator S3 is connected to an external power supply ES4 (15V power supply in this embodiment), its power supply pin Vee is grounded, its positive input pin is connected to the phase-shifting device 380A (i.e., connected to the phase-shifting resistor R12 and the phase-shifting capacitor C3) and is connected to ground (GND) through the resistor R13; its negative input pin is connected to the reference voltage input device Vth2 for providing the reference voltage; its output pin is connected to the gate of the second transistor T1 through the series-connected resistor R15 and the isolation capacitor C5 and is connected to the external power supply ES5 (5V power supply in this embodiment) through the resistor R14 and grounded (GND) through the capacitor C4.
[0056] The gate of the second transistor T1 is grounded (GND) through the resistor R16, its source is grounded (GND), and its drain is connected to the gate of the first transistor T2 via the resistor R11.
[0057] The PWM on / off signal output by the gate driver 320 serves as the input control signal for the second comparator S3 in the anti-mis-triggering device 380. When the phase-shifted voltage output by the phase-shifting device 380A in the anti-mis-triggering device 380 is higher than the reference voltage, the second comparison signal output by the second comparator S3 is a high-level signal to turn on the second transistor T1, and when the boost capacitor C bs is in overvoltage and the voltage of the first comparison signal output by the first comparator S2 is higher than the gate voltage of the first transistor T2, the first transistor T2 is also turned on. The control device 3604B receives the first comparison signal and outputs a turn-off signal to the gate driver 320 to turn off the input terminals HIN and LIN of the gate driver 320 and prevent the floating voltage detection and control device 360 from being mis-triggered; or when the boost capacitor C bs is not in overvoltage and the voltage of the first comparison signal output by the first comparator S2 is lower than the gate voltage of the first transistor T2, the first transistor T2 is turned off, and the control device 3604B cannot receive the first comparison signal output by the first comparator S2, so that no turn-off signal is output to the gate driver 320.
[0058] When the phase-shifted voltage output by the phase-shifting device 380A is less than the reference voltage, the second comparison signal output by the second comparator S3 is a low-level voltage, the second transistor T1 and the first transistor T2 are turned off, and the control device 3604B cannot receive the first comparison signal output by the first comparator S2, so that no turn-off signal is output to the gate driver 320.
[0059] As Figure 5 shown, the floating voltage detection and control device 360 and the anti-mis-triggering device 380 include a number of resistors (R1-R16) and capacitors (C1-C4). 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 of resistors and capacitors adopted in this embodiment and their connection methods do not limit the protection scope of the present invention.
[0060] In the embodiment of the present invention, the overvoltage across the bootstrap capacitor C bs is taken as an example for illustration. However, 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 across the bootstrap capacitor C bs and perform corresponding control on the gate driver to protect the inverter device.
[0061] The inverter device described in the embodiment of the present invention can be used to provide an electrical signal to a motor. 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 provided 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. The inverter device is used to provide an electrical signal to the motor.
[0063] Although various embodiments have been described, it is obvious to those of ordinary skill in the art that the present invention is not limited except for the appended claims and their equivalents. Regarding the various functions performed by the components or structures (components, devices, circuits, etc.) described above, unless otherwise indicated, the terms (including references to "devices") used to describe such components are intended to correspond to any component or structure that performs the specified function of the described component (i.e., functionally equivalent), even if it is not structurally equivalent to the disclosed structure that performs the function in the exemplary embodiments of the present invention shown herein.
[0064] In addition, the appended claims are hereby incorporated into the detailed description, where each claim can independently serve as a separate exemplary embodiment. Although each claim can independently serve as a separate exemplary embodiment, it should be noted that even though a dependent claim may recite a particular combination with one or more other claims in the claims, other exemplary embodiments may also include combinations of the dependent claim with the subject matter of each other dependent claim or independent claim. Such combinations are presented herein unless it is stated that they are not intended. In addition, even if a 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) including a bootstrap capacitor (C bs ), characterized in that, The driving circuit (300) further includes: Floating voltage detection and control device (360) for detecting the floating voltage of the boost capacitor (C bs ) and controlling the operation of the gate driver (320) accordingly; and An anti-mis-triggering device (380) for preventing the floating voltage detection and control device (360) from being mis-triggered. Wherein, the floating voltage detection and control device (360) is connected between the positive terminal (Vcbs+) and the negative terminal (Vcbs-) of the bootstrap capacitor (Cbs) of the bootstrap circuit (340) and is connected to the anti-mis-triggering device (380) and the gate driver (320).
2. The drive circuit according to claim 1, characterized in that, The bootstrap circuit (340) further includes a bootstrap diode (D bs bs). The positive electrode of the bootstrap diode (Dbs) is connected to the power supply terminal (VDD) of the gate driver (320) and an external power supply (VCC), and its negative electrode is connected to the positive terminal (Vcbs+) of the bootstrap capacitor (Cbs). The positive terminal (Vcbs+) of the bootstrap capacitor (Cbs) is also connected to the power supply terminal (VB) of the high-side switch drive output circuit of the gate driver (320), and its negative terminal is connected to the power supply terminal (VS) of the low-side switch drive output circuit of the gate driver (320). Moreover, the power supply terminal (VS) of the low-side switch drive output circuit is also connected to a drive output node (A) connected to a load (M).
3. The drive circuit according to claim 1, characterized in that, The floating voltage detection and control device (360) includes: A floating voltage detection device (3602) connected between the positive terminal (Vcbs+) and the negative terminal (Vcbs-) of the bootstrap capacitor (Cbs) for detecting the floating voltage of the bootstrap capacitor (Cbs); And A detection and control device (3604) whose input terminal is connected to the output terminal of the floating voltage detection device (3602), whose control terminal is connected to the anti-mis-triggering device (380), and whose output terminal is connected to the input terminal or the enable terminal of the gate driver (320), for receiving the floating voltage of the bootstrap capacitor (Cbs) output by the floating voltage detection device (3602), and accordingly controlling the operation of the gate driver (320), and being prevented from being mis-triggered by the anti-mis-triggering device (380).
4. The drive circuit according to claim 3, characterized in that The floating voltage detection device (3602) is a differential sampling and subtraction circuit, including an operational amplifier (S1). One power supply pin (Vcc) of the operational amplifier (S1) is connected to a first external power supply (ES1), its other power supply pin (Vee) is grounded (GND), its positive input pin is connected to the positive terminal (Vcbs+) of the bootstrap capacitor (Cbs) and is grounded, its negative input pin is connected to the negative terminal (Vcbs-) of the bootstrap capacitor (Cbs) and is grounded (GND), and its output pin outputs the obtained floating voltage of the bootstrap capacitor (Cbs).
5. The drive circuit according to claim 3 or 4, characterized in that, The detection and control device (3604) includes a threshold comparison device (3604A), a first transistor (T2), and a control device (3604B), wherein, The threshold comparison device (3604A) is connected to the output terminal of the floating voltage detection device (3602) and is connected to the source electrode of the first transistor (T2), for receiving the floating voltage of the bootstrap capacitor (Cbs) output by the floating voltage detection device (3602), and comparing the floating voltage with a predetermined threshold voltage to output a first comparison signal; The source electrode of the first transistor (T2) is connected to the output terminal of the threshold comparison device (3604A), its drain electrode is connected to the control device (3604B), its gate electrode is connected to the anti-mis-triggering device (380), and The control device (3604B) is respectively connected to the drain of the first transistor (T2) and the input terminal or the enable terminal of the gate driver (320), and is configured to receive the first comparison signal from the threshold comparison device (3604A) transmitted when the first transistor (T2) conducts when the boost capacitor (Cbs) is over-voltage, and output a turn-off signal to turn off the input terminal or the enable terminal of the gate driver (320).
6. The drive circuit according to claim 5, wherein The threshold comparison device (3604A) includes a first comparator (S2) and a threshold voltage input device (Vth1) for providing the predetermined threshold voltage. Among them, The power supply pin Vcc of the first comparator (S2) is connected to the second external power supply (ES2), its power supply pin Vee is grounded (GND), its positive input pin is connected to the output pin of the floating voltage detection device (3602), its negative input pin is connected to the threshold voltage input device (Vth1), and its output pin is connected to the third external power supply (ES3) and the source of the first transistor (T2) to output the first comparison signal. The first comparator (S2) is configured to receive the floating voltage of the boost capacitor (Cbs) output by the floating voltage detection device (3602), and compare the floating voltage with the predetermined threshold voltage provided by the threshold voltage input device (Vth1) to output the first comparison signal to the first transistor (T2), and When the boost capacitor (C bs ) is overvoltage, the voltage of the first comparison signal output by the first comparator (S2) is higher than the gate voltage of the first transistor (T2), and the first transistor (T2) is turned on to transmit the first comparison signal output by the first comparator (S2) to the control device (3604B).
7. The drive circuit according to claim 6, characterized in that, The anti-mis-triggering device (380) is used to prevent the floating voltage detection device (3602) and the threshold comparison device (3604A) in the detection control device (3604) from being mis-triggered. The anti-mis-triggering device (380) includes a phase shift device (380A) and a logic gate control device (380B).
8. The drive circuit according to claim 7, wherein The phase shift device (380A) is configured to perform a phase shift on the voltage pulse from the input terminal or the output terminal of the gate driver (320) to output a phase-shifted voltage. Among them, the phase shift device (380A) includes a phase shift resistor (R12) and a phase shift capacitor (C3). One end of the phase shift resistor (R12) is connected to the input terminal or the output terminal of the gate driver (320), and the other end is connected to one end of the phase shift capacitor (C3) and the positive input pin of the logic gate control device (380B). The other end of the phase shift capacitor (C3) is grounded (GND).
9. The drive circuit according to claim 7 or 8, wherein The logic gate control circuit (380B) includes a second comparator (S3) and a second transistor (T1). Among them, the second comparator (S3) is configured to compare the phase-shifted voltage output by the phase shift device (380A) with a reference voltage and output a second comparison signal, and control the conduction and turn-off of the second transistor (T1) according to the second comparison signal.
10. The drive circuit according to claim 9, wherein The logic gate control circuit (380B) further includes a reference voltage input device (Vth2) for providing the reference voltage.
11. The drive circuit according to claim 10, wherein a power supply pin (Vcc) of the second comparator (S3) is connected to a fourth external power supply (ES4), another power supply pin (Vee) thereof is grounded (GND), a positive input pin thereof is connected to the phase shift device (380A) and grounded (GND), a negative input pin thereof is connected to the reference voltage input device (Vth2), and an output pin thereof is connected to a gate of the second transistor (T1) and a fifth external power supply (ES5), and is grounded (GND) through a capacitor (C4); and / or the gate and the source of the second transistor (T1) are grounded (GND), and a drain thereof is connected to a gate of the first transistor (T2).
12. An inverter device (2) comprising a power inverter (100) and a drive circuit (300) according to any one of claims 1 to 11, wherein a high-side switch pulse output terminal (HO) and a low-side switch pulse output terminal (LO) of a gate driver (320) in the drive circuit (300) are respectively connected to a high-side switch and a low-side switch of the power inverter (100), and the high-side switch and the low-side switch of the power inverter (100) are connected to a drive output node (A) connected to a load (M) of the drive circuit (300).
13. A vehicle comprising the inverter device (2) according to claim 12 and an electric motor, the inverter device (2) being configured to supply an electrical signal to the electric motor.