Method and device for controlling inverter circuit, controller and inverter device

Abstract

The embodiment of the invention relates to a method and device for controlling an inverter circuit, a controller and an inverter device. The method comprises the step of controlling to disconnect the connection between the inverter circuit and the power supply in response to receiving a power-off request for the inverter circuit. The method also includes generating a pulse width modulated signal. The method further includes controlling a target power device in the inverter circuit to be turned on according to the generated pulse width modulated signal. During turn-on of the target power device, charge stored by an energy storage device in the inverter circuit is at least partially released through the target power device. According to the method, the target power device in the inverter circuit can be utilized to at least partially release the charges stored by the energy storage device in the power-off process of the inverter circuit, so that the electrical safety requirement is met. According to the method, external hardware equipment is not needed, so that hardware resources and cost can be saved.

Description

Technical Field

[0001] The embodiments of this disclosure generally relate to the field of circuit technology, and more particularly to methods, apparatus, controllers, and inverter devices for controlling inverter circuits. Background Technology

[0002] An inverter is a converter that transforms direct current (DC) into alternating current (AC). Currently, inverters are widely used in vehicles. The DC power stored in the vehicle's high-voltage battery is converted into AC power by the inverter to power, for example, the vehicle's motor. Because these inverters convert high voltages, they must meet electrical safety requirements. Summary of the Invention

[0003] Embodiments of this disclosure provide a method, apparatus, controller, and inverter device for controlling inverter circuits.

[0004] According to a first aspect of this disclosure, a method for controlling an inverter circuit is provided. The method includes: in response to receiving a power-down request for the inverter circuit, controlling the disconnection of the inverter circuit from a power source. The method further includes generating a pulse width modulation (PWM) signal. The method further includes controlling a target power device in the inverter circuit to turn on according to the generated PWM signal. During the turn-on period of the target power device, at least partially released charge stored in an energy storage device in the inverter circuit is released through the target power device.

[0005] According to a second aspect of this disclosure, an apparatus for controlling an inverter circuit is provided. The apparatus includes a receiving unit, a first control unit, a generating unit, and a second control unit. The receiving unit is configured to receive a power-down request for the inverter circuit. The first control unit is configured to control the disconnection of the inverter circuit from a power source. The generating unit is configured to generate a pulse-width modulation (PWM) signal. The second control unit is configured to control a target power device in the inverter circuit to conduct according to the generated PWM signal. During the conduction of the target power device, at least partially of the charge stored in an energy storage device in the inverter circuit is released through the target power device.

[0006] According to a third aspect of this disclosure, a controller is provided. The controller includes at least one processor and a memory. The memory is coupled to the at least one processor and has instructions stored thereon. When executed by the at least one processor, the instructions cause the controller to perform the methods provided according to a first aspect of this disclosure.

[0007] According to a fourth aspect of this disclosure, an inverter device is provided. The inverter device includes an inverter circuit and a controller provided according to a first aspect of this disclosure. The inverter circuit includes power devices and energy storage devices.

[0008] According to a fifth aspect of this disclosure, a program product is provided. The program product is tangibly stored on a non-volatile, i.e., machine-readable medium and includes machine-executable instructions. When executed, the machine-executable instructions cause a machine to perform the method provided according to a first aspect of this disclosure.

[0009] According to a sixth aspect of this disclosure, a machine-readable storage medium is provided. Machine-executable instructions are stored on the machine-readable storage medium. These machine-executable instructions are executed by a processor to implement the method provided according to a first aspect of this disclosure.

[0010] According to a seventh aspect of this disclosure, a vehicle is provided. The vehicle includes an inverter device provided according to a fourth aspect of this disclosure. Attached Figure Description

[0011] The above and other objects, features and advantages of this disclosure will become more apparent from the accompanying drawings, in which like reference numerals generally denote like parts.

[0012] Figure 1 A schematic diagram of an example environment in which the apparatus and / or methods according to embodiments of the present disclosure may be implemented is shown;

[0013] Figure 2 An exemplary circuit diagram of an inverter device is shown;

[0014] Figure 3 An exemplary flowchart of a method for controlling an inverter circuit according to an embodiment of the present disclosure is shown;

[0015] Figure 4 An exemplary circuit diagram of an inverter device according to an embodiment of the present disclosure is shown;

[0016] Figure 5 An exemplary schematic diagram of a process for generating a pulse width modulation signal according to an embodiment of the present disclosure is shown;

[0017] Figure 6 An exemplary circuit diagram of a voltage detection circuit according to an embodiment of the present disclosure is shown;

[0018] Figure 7 Another exemplary schematic diagram of the process of generating a pulse width modulation signal according to an embodiment of the present disclosure is shown;

[0019] Figure 8 An exemplary graph showing the relationship between a target current value and ambient temperature according to an embodiment of the present disclosure is shown;

[0020] Figure 9 An exemplary circuit diagram of a temperature detection circuit according to an embodiment of the present disclosure is shown;

[0021] Figure 10 A schematic diagram is shown illustrating the process of controlling the discharge of an energy storage device in an inverter circuit according to an embodiment of the present disclosure;

[0022] Figure 11 A schematic block diagram of an apparatus for controlling an inverter circuit according to an embodiment of the present disclosure is shown.

[0023] Figure 12 A schematic block diagram of a controller suitable for implementing embodiments of the present disclosure is shown.

[0024] In the various accompanying figures, the same or corresponding labels indicate the same or corresponding parts. It should be noted that the elements in the accompanying figures are schematic and not drawn to scale. Detailed Implementation

[0025] Embodiments of this disclosure will now be described in more detail with reference to the accompanying drawings. While some embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided to provide a more thorough and complete understanding of this disclosure. It should be understood that the accompanying drawings and embodiments of this disclosure are for illustrative purposes only and are not intended to limit the scope of protection of this disclosure.

[0026] In the description of embodiments of this disclosure, the term "comprising" and similar terms should be understood as open-ended inclusion, i.e., "including but not limited to". The term "based on" should be understood as "at least partially based on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment". The terms "first", "second", etc., may refer to different or the same objects. Other explicit and implicit definitions may also be included below.

[0027] Unless otherwise defined, all terms used herein (including technical and scientific terms) shall have the same meaning as commonly understood by one of ordinary skill in the art to which this subject matter pertains. It will be further understood that terms such as those defined in commonly used dictionaries shall be interpreted as having the meaning consistent with their meaning in the context of the specification and in the relevant art, and shall not be interpreted in an idealized or overly formal form unless otherwise explicitly defined herein. As used herein, the statement of “connecting” or “coupling” two or more parts together shall mean that these parts are directly joined together or joined through at least one intermediate component.

[0028] As mentioned earlier, an inverter is used in the vehicle to convert the direct current (DC) stored in the high-voltage battery into alternating current (AC). This AC power is used, for example, to power the vehicle's electric motor. This motor is, for example, a permanent-magnet synchronous motor (PMSM). Such vehicles can be, for example, electric two-wheelers (eScooters) or other electric vehicles.

[0029] In the context of this disclosure, an inverter is alternatively referred to as an inverter device. An inverter device may include inverter circuitry and a controller. The controller is used to control the operation of the inverter circuitry. One or more energy storage devices (e.g., capacitors) are provided in the inverter circuitry to reduce voltage and current ripple in the inverter circuitry. During operation of the inverter device, voltage from a high-voltage battery charges the energy storage devices. Such energy storage devices typically have large capacitance values ​​due to the need to store high voltage.

[0030] After the vehicle is turned off (inverter powered down), the high-voltage battery needs to be disconnected from the inverter. However, the energy storage device still stores high voltage at this time, posing a safety hazard. In some implementations, an external DC-DC converter can be used to discharge the energy storage device. However, using an external DC-DC converter increases hardware cost and size. Therefore, this disclosure proposes a method that utilizes components within the inverter circuit to at least partially release the charge stored in the energy storage device during the inverter circuit's power-off process, thereby meeting electrical safety requirements. This method does not require external hardware devices, thus saving hardware resources and costs.

[0031] The embodiments of this disclosure will now be described in further detail with reference to the accompanying drawings, wherein... Figure 1 Example environments in which apparatus and / or methods according to embodiments of the present disclosure may be implemented are shown.

[0032] like Figure 1 As shown, example environment 1 includes a vehicle 10. The vehicle 10 may include an inverter device 200, a power supply 101 (e.g., a battery), a relay 102, a motor 103, a vehicle control unit (VCU) 104, etc. The power supply 101 is coupled to the inverter device 200 via the relay 102. When the relay 102 is closed, the drive control unit (DCU) 221 in the inverter device 200 generates a drive control signal to control the inverter device 200 to convert the DC power from the power supply 101 into AC power for the motor 103. The vehicle control unit 104 can control the power-on and power-off of the inverter device 200.

[0033] Figure 2An exemplary circuit diagram of an inverter device 200 is shown. The inverter device 200 includes an inverter circuit 210 and a control circuit 220. The inverter circuit 210 includes power devices (e.g., transistors) UH1, UL1, UH2, UL2, VH1, VL1, VH2, VL2, WH1, WL1, WH2, WL2 and an energy storage device (e.g., a capacitor) C1. When the relay 102 is closed, the energy storage device C1 is capable of storing charge from the power source 101. Figure 2 The inverter circuit 210 shown is a three-phase inverter circuit. In the first phase, the upper bridge arm includes power devices UH1 and UH2, and the lower bridge arm includes power devices UL1 and UL2. In the second phase, the upper bridge arm includes power devices VH1 and VH2, and the lower bridge arm includes power devices VL1 and VL2. In the third phase, the upper bridge arm includes power devices WH1 and WH2, and the lower bridge arm includes power devices WL1 and WL2.

[0034] The control circuit 220 may include a drive control unit (DCU) 221 and a gate drive unit (GDU) 222. During normal operation (power-on) of the inverter device 200, the DCU 221 generates drive control signals for each arm of each phase. The DCU 221 may include phase shifting circuitry such that the phases of the drive control signals for the three phases differ by 120 degrees from each other. The GDU 222 boosts the drive control signals to generate drive signals with stronger drive force accordingly. Drive signal S1 is used to control power devices UH1 and UH2. Drive signal S2 is used to control power devices UL1 and UL2. Drive signal S3 is used to control power devices VH1 and VH2. Drive signal S4 is used to control power devices VL1 and VL2. Drive signal S5 is used to control power devices WH1 and WH2. Drive signal S6 is used to control power devices WL1 and WL2. Drive signals S1 and S2 alternately remain active to alternately turn on power devices UH1, UH2 and UL1, UL2. Similarly, drive signals S3 and S4 alternately remain active to alternately turn on power devices VH1, VH2 and VL1, VL2. Drive signals S5 and S6 alternately remain active to alternately turn on power devices WH1, WH2 and WL1, WL2. Figure 2 In the example, the six pins of the GDU 222 are electrically connected to six groups of power devices. Each group of power devices belongs to the same half-bridge, and the two power devices in each group share one pin.

[0035] After receiving a power-down request from the vehicle control unit 104, the DCU 221 in the inverter unit 200 can stop generating drive control signals and control the relay 102 to disconnect. However, at this time, the energy storage device C1 is still at a high voltage, which does not meet the electrical safety requirements.

[0036] Figure 3 An exemplary flowchart of a method 300 for controlling an inverter circuit according to an embodiment of the present disclosure is shown. Method 300 can be performed by a means for controlling the inverter circuit. This means can be implemented in software and / or hardware, for example, as a controller. The controller may be, for example, a... Figure 2 The DCU 221 in the example. Next, taking the controller as the execution subject, method 300 will be illustrated schematically. (Reference) Figure 3 Method 300 may include boxes 302 to 306.

[0037] At box 302, if a power-down request for the inverter circuit is received, the controller disconnects the inverter circuit from the power supply. Here, "connection" refers to electrical connection. After the electrical connection between the inverter circuit and the power supply is broken, the inverter circuit is no longer supplied with power, and the energy storage devices in the inverter circuit are no longer charged.

[0038] At box 304, the controller generates a pulse width modulation (PWM) signal. A PWM signal is a periodic pulse signal. The duty cycle can be used to represent the percentage of the pulse signal that is high during the entire pulse period.

[0039] At block 306, the controller controls the target power device in the inverter circuit to turn on according to the generated pulse width modulation (PWM) signal. The target power device is turned on while the PWM signal is at an active level. If the target power device is an N-type transistor, the active level of the PWM signal is high. If the target power device is a P-type transistor, the active level of the PWM signal is low. During the conduction of the target power device, the charge stored in the energy storage device in the inverter circuit is at least partially released through the target power device. Because the target power device has on-resistance, it helps to dissipate the charge stored in the energy storage device during conduction. Furthermore, during the conduction of the target power device, the charge stored in the energy storage device can also be dissipated through a portion of the wires in the inverter circuit.

[0040] It should be noted that during the control of the inverter circuit, the operations at block 304 and block 306 can be repeated. The method 300 for controlling an inverter circuit according to embodiments of this disclosure can utilize target power devices within the inverter circuit to at least partially release the charge stored in the energy storage device during the power-down process of the inverter circuit, thereby meeting electrical safety requirements. This method does not require external hardware devices, thus saving hardware resources and costs.

[0041] In some embodiments of this disclosure, the target power device may include target power devices located in one or more phases of the inverter circuit. The target power device in each of the one or more phases includes at least one power device located in the upper half-bridge and at least one power device located in the lower half-bridge of that phase. In one example, the target power device in each phase includes all power devices located in that phase. When the inverter device is a three-phase inverter, the target power device may include target power devices in any one of the three phases, target power devices in any two of the three phases, or target power devices in all three phases. The target power device in each phase includes at least one power device located in the upper half-bridge and at least one power device located in the lower half-bridge of that phase.

[0042] Figure 4 An exemplary circuit diagram of an inverter device 400 according to an embodiment of the present disclosure is shown. (Refer to...) Figure 4 For example, the target power device may include one or more of the following: power devices UH1, UH2, UL1, UL2 in the first phase, power devices VH1, VH2, VL1, VL2 in the second phase, or power devices WH1, WH2, WL1, WL2 in the third phase. Figure 4 In the example, the power devices in a single half-bridge of each phase are controlled by the same drive signal. Therefore, the target power devices for each phase include all power devices in that phase. After the inverter circuit is powered down, independent drive signals PWM1, PWM2, PWM3, PWM4, PWM5, and PWM6 can be output from the six pins of the GDU 222. By controlling the drive signals PWM1, PWM2, PWM3, PWM4, PWM5, and PWM6, the power devices in the upper and lower half-bridges of at least one of the three phases can be turned on simultaneously. The power devices in multiple target phases of the three phases can be turned on simultaneously. The more target phases there are, the smaller the equivalent total resistance between node B+ and node B-, and the larger the current flowing through the power devices. Here, when all three phases' power devices are turned on, the drive signals PWM1, PWM2, PWM3, PWM4, PWM5, and PWM6 can be synchronous PWM signals without phase shift.

[0043] exist Figure 4In an alternative example, if multiple (e.g.) are in each half-bridge Figure 4 If the two power devices in the energy storage device are each controlled by a separate drive signal, then the target power device in each phase may include at least one power device in the upper half-bridge and at least one power device in the lower half-bridge of that phase. In this way, even if not all power devices in a single half-bridge are turned on, the upper and lower half-bridges can be turned on together to at least partially release the charge stored in the energy storage device.

[0044] In one example, node B+ is high and node B- is low (e.g., grounded). When the target power device is on, node B+ is coupled to node B- via the target power device, and the charge on node B+ (corresponding to the upper plate of energy storage device C1) is consumed by the on-resistance of the target power device. It should be noted that although... Figure 4 The inverter circuit 410 shown is a three-phase inverter circuit, but the inverter circuit 410 can also be a single-phase inverter circuit.

[0045] The power devices in inverter circuit 410 typically need to meet operating specifications, such as operating within their rated current range. Excessive current flowing through the power devices can damage them. Therefore, embodiments of this disclosure propose monitoring the current flowing through the power devices and using the monitored current to adjust the duty cycle of a pulse width modulation signal, thereby controlling the current flowing through the power devices within their rated current range to prevent damage. In this context, the monitored current is referred to as the "feedback current." In some embodiments of this disclosure, "monitoring" may refer to real-time monitoring.

[0046] In some embodiments of this disclosure, the controller obtains the current value of the feedback current flowing through the target power device in the inverter circuit. The current value of the feedback current can be obtained, for example, through... Figure 4 The current is obtained from the current detection circuit 411 and provided to the DCU 421. The current detection circuit 411 can be arranged between node N1 and node B-, and can be arranged... Figure 4Other locations shown may be used, or the feedback current may be located at other locations where it can be measured. When the target power device includes a power device located in a single phase of the inverter circuit 410, the current detection circuit 411 may be arranged in that single phase, and the controller may determine the current value of the current flowing through the power device in that single phase as the feedback current value. When the target power device includes power devices located in multiple phases of the inverter circuit 410, the current detection circuit 411 may be arranged in all of those multiple phases. The controller may obtain the current value of the current flowing through the power device in each of the multiple phases through the current detection circuit 411, calculate the average current value of the current flowing through the power devices in all of the multiple phases based on the current values ​​of the current flowing through the power devices in each phase, and determine the average current value of the current flowing through the power devices in all of the multiple phases as the feedback current value.

[0047] Then, the controller adjusts the duty cycle of the pulse width modulation signal based on the target current value and the feedback current value. The target current value can be a value within the rated current range of the aforementioned power device. In some embodiments of this disclosure, during the adjustment of the duty cycle of the pulse width modulation signal based on the target current value and the feedback current value, the controller determines the current difference between the target current value and the feedback current value. The controller then adjusts the duty cycle of the pulse width modulation signal based on the current difference. When the target power device is an N-type transistor, the duty cycle is directly proportional to the current difference. The larger the current difference, the larger the duty cycle. The smaller the current difference, the smaller the duty cycle. When the target power device is a P-type transistor, the duty cycle is inversely proportional to the current difference. The larger the current difference, the smaller the duty cycle. The smaller the current difference, the larger the duty cycle.

[0048] Next, the controller generates a pulse width modulation (PWM) signal according to the adjusted duty cycle. When the target power device is an N-type transistor, a larger PWM duty cycle results in a longer on-time for the target power device, and therefore a larger feedback current. When the target power device is a P-type transistor, a smaller PWM duty cycle results in a longer on-time for the target power device, and therefore a larger feedback current.

[0049] Through the exemplary process of the above embodiments, the duty cycle of the pulse width modulation signal can be adjusted to make the current value of the feedback current gradually approach the target current value until it equals the target current value.

[0050] In some embodiments of this disclosure, the controller may also limit the duty cycle within a target range. This target range is determined by an upper limit and a lower limit. After adjusting the duty cycle of the pulse width modulation signal based on the current difference, the controller determines whether the adjusted duty cycle is higher than the upper limit or lower than the lower limit. If the adjusted duty cycle is higher than the upper limit, the controller adjusts the adjusted duty cycle to the upper limit. If the adjusted duty cycle is lower than the lower limit, the controller adjusts the adjusted duty cycle to the lower limit.

[0051] Figure 5 An exemplary schematic diagram illustrating a process for generating a pulse width modulation signal according to an embodiment of the present disclosure is shown. Reference is made below. Figure 5 The following example illustrates the process of generating a pulse width modulated signal. It should be noted that... Figure 5 The process shown can be performed cyclically to dynamically adjust the pulse width modulation signal based on the feedback current.

[0052] At box 550, the controller determines the target current value I_tar. The target current value I_tar can be determined based on the rated current range of the power device. In one example, the target current value I_tar can be set to any value within the rated current range of the power device. In another example, the target current value I_tar can be set to the upper limit of the rated current range of the power device, which can improve the rate of charge release in the energy storage device.

[0053] For example, after the current detection circuit 411 obtains the current value I_fb of the feedback current, the current value I_fb of the feedback current is stored in the controller at block 510. In some embodiments of this disclosure, when the target power device is an N-type transistor, the duty cycle of the initial pulse width modulation signal can be set to 0%. When the target power device is a P-type transistor, the duty cycle of the initial pulse width modulation signal can be set to 100%. Thus, initially the target power device is not turned on, and the initial current value I_fb of the feedback current is 0A.

[0054] The subtractor Sub subtracts the target current value I_tar from the feedback current value I_fb to obtain the current difference ΔI between the target current value I_tar and the feedback current value I_fb. ΔI = I_tar - I_fb. At block 520, a proportional-integral (PI) controller can be used to obtain the duty cycle Dutyc1 of the pulse width modulation (PWM) signal from the current difference ΔI. The PPI controller can be configured such that the duty cycle Dutyc1 is proportional to the current difference ΔI. The larger the current difference ΔI, the larger the duty cycle Dutyc1. The smaller the current difference ΔI, the smaller the duty cycle Dutyc1.

[0055] At box 530, the duty cycle Dutyc1 is limited to the target range. If the duty cycle Dutyc1 is higher than the upper limit, the controller adjusts the duty cycle Dutyc1 to the upper limit. Thus, the final duty cycle Dutyc2 is equal to the upper limit. If the duty cycle Dutyc1 is lower than the lower limit, the controller adjusts the duty cycle Dutyc1 to the lower limit. Thus, the final duty cycle Dutyc2 is equal to the lower limit. If the duty cycle Dutyc1 is within the target range, the value of Dutyc1 is not changed. Thus, the final duty cycle Dutyc2 is equal to Dutyc1.

[0056] At box 540, a pulse width modulation (PWM) signal is generated based on the final duty cycle Dutyc2. The final duty cycle Dutyc2 can be used to configure the percentage of time the PWM signal is high within a single pulse cycle.

[0057] In some embodiments of this disclosure, the current detection circuit 411 may include a current acquisition circuit and a first analog-to-digital converter (ADC) circuit. The current acquisition circuit is configured to acquire the feedback current flowing through the target power device in the inverter circuit 410. The current acquisition circuit may be implemented, for example, by a current sensor. The first ADC circuit is configured to perform analog-to-digital conversion on the feedback current to obtain the current value I_fb of the feedback current.

[0058] In some other embodiments of this disclosure, the current detection circuit 411 may be replaced by a voltage detection circuit. Figure 6 An exemplary circuit diagram of a voltage detection circuit according to an embodiment of the present disclosure is shown. The voltage detection circuit may include: a first resistor R1, an operational amplifier AMP, and a first analog-to-digital converter 4111. The first resistor R1 is connected in series with the target power device. Reference Figure 4 A first resistor R1 can be placed between node N1 and node B-. The first input terminal of the operational amplifier AMP is coupled to the first terminal of the first resistor R1. The second input terminal of the operational amplifier AMP is coupled to the second terminal of the first resistor R1. A first analog-to-digital converter circuit 4111 is coupled to the output terminal of the operational amplifier AMP. The first analog-to-digital converter circuit 4111 is configured to perform analog-to-digital conversion on the feedback voltage UU output from the output terminal of the operational amplifier AMP to obtain the voltage value Out_fb of the feedback voltage UU. The controller can... Figure 5 In box 510, the feedback current value I_fb flowing through the target power device in inverter circuit 410 is determined based on the feedback voltage value Out_fb of UU and the resistance value of the first resistor R1. I_fb = Out_fb / (G × R1). Out_fb represents the feedback voltage value UU. G represents the gain of the operational amplifier AMP. R1 represents the resistance value of the first resistor R1.

[0059] In some further embodiments of this disclosure, the effect of the ambient temperature of the inverter circuit 410 on the rated current range of the power devices is also considered. (See reference...) Figure 7 At block 770, a temperature detection circuit 770 can be used to obtain a reference voltage value Ut that varies with the ambient temperature of the inverter circuit 410. At block 760, the controller determines the ambient temperature Tm of the inverter circuit 410 based on the reference voltage value Ut. At block 550, the controller determines the target current value I_tar based on the ambient temperature Tm. The ambient temperature Tm is inversely proportional to the target current value I_tar. Figure 8 An exemplary graph showing the relationship between a target current value I_tar and ambient temperature Tm according to an embodiment of this disclosure is shown. It should be understood that... Figure 8 This is merely an example, not a limitation on the relationship between the target current value I_tar and the ambient temperature Tm. The relationship between the target current value I_tar and the ambient temperature Tm can also have other inverse relationships.

[0060] Figure 9 An exemplary circuit diagram of a temperature detection circuit 770 according to an embodiment of the present disclosure is shown. The temperature detection circuit 770 may include: a second resistor R2, a thermistor NTC, and a second analog-to-digital converter circuit 771. A first terminal of the second resistor R2 is coupled to a first voltage terminal V1. A second terminal of the second resistor R2 is coupled to a first node. A first terminal of the thermistor NTC is coupled to the first node. A second terminal of the thermistor NTC is coupled to a second voltage terminal V2. The second analog-to-digital converter circuit 771 is configured to perform analog-to-digital conversion on the voltage difference between the first and second terminals of the thermistor NTC to obtain a reference voltage value Ut. The voltage difference satisfies the following equation:

[0061] ΔU=((V1-V2) ×R NTC ) / (R2+ R NTC (1)

[0062] Where ΔU represents the voltage difference between the first and second terminals of the thermistor NTC, V1 represents the voltage value at the first voltage terminal, V2 represents the voltage value at the second voltage terminal, and R... NTC R1 represents the resistance value of the thermistor NTC, and R2 represents the resistance value of the second resistor R2.

[0063] According to equation (1), we can obtain:

[0064] R NTC =(ΔU×R2) / (V1-V2-ΔU) (2)

[0065] Under varying ambient temperature Tm, the resistance R of the thermistor NTC... NTC As it changes, therefore, it is possible Figure 7 R at position 760 is calculated according to equation (2). NTC The ambient temperature Tm is determined by a table showing the relationship between the resistance value of the thermistor (NTC) and the ambient temperature Tm.

[0066] In some embodiments of this disclosure, the second analog-to-digital converter circuit 771 may be the same analog-to-digital converter circuit as the first analog-to-digital converter circuit 4111.

[0067] Figure 10 A schematic diagram illustrating the process of discharging the energy storage device in the inverter circuit 410 according to an embodiment of the present disclosure is shown. At block 1002, after receiving an instruction to shut down the vehicle (power off the vehicle), the vehicle control unit 104 sends a power-down request for the inverter circuit 410 to the DCU 421. The power-down request instructs the inverter circuit 410 to be powered down. At block 1004, the DCU 421 stops generating drive control signals for controlling the normal operation of the inverter circuit 410. At block 1006, the DCU 421 sends a shutdown request to the controller of the power supply 101. The shutdown request controls the disconnection of relay 102 between the inverter circuit 410 and the power supply 101. At block 1008, the controller of the power supply 101 receives the shutdown request. At block 1010, the controller of the power supply 101 disconnects relay 102. At block 1012, the controller of the power supply 101 sends a message to the DCU 421 indicating that the relay is disconnected. At block 1014, the controller of power supply 101 is powered down. At block 1016, DCU 421 determines that the connection between inverter circuit 410 and power supply 101 has been disconnected based on the disconnected state of the relay. At block 1018, DCU 421 generates an initial pulse width modulation (PWM) signal. The duty cycle of the initial PWM signal can be 0%. At block 1020, DCU 421 adjusts the duty cycle of the PWM signal based on the feedback current value I_fb. At block 1024, DCU 421 detects the voltage value of the energy storage device. If the voltage value of the energy storage device is lower than the target voltage value (e.g., 60V), DCU 421 stops generating the PWM signal. At block 1026, DCU 421 is powered down when the voltage value of the energy storage device is lower than the target voltage value. In this way, inverter circuit 410 meets electrical safety requirements.

[0068] As an example application scenario, in situations where the load on a vehicle does not require a low-voltage 12V power supply but can be powered by a high-voltage power supply, a DC-DC converter is unnecessary. Utilizing the method and apparatus disclosed herein for controlling the inverter circuit, the high voltage can be discharged to a target voltage value during the power-down phase to prevent electric shock to the user during vehicle maintenance or a collision. The vehicle here can be a two-wheeled electric vehicle, such as an eScooter.

[0069] Figure 11 A schematic block diagram of an apparatus 1100 for controlling an inverter circuit 410 according to an embodiment of the present disclosure is shown. Figure 11 As shown, the device 1100 includes: a receiving unit 1102, a first control unit 1104, a generating unit 1106, and a second control unit 1108. The receiving unit 1102 is configured to receive a power-down request for the inverter circuit 410. The first control unit 1104 is configured to control the disconnection of the inverter circuit 410 from the power supply 101. The generating unit 1106 is configured to generate a pulse-width modulation (PWM) signal. The second control unit 1108 is configured to control a target power device in the inverter circuit 410 to be turned on according to the generated PWM signal. During the on-time of the target power device, at least partially of the charge stored in the energy storage device in the inverter circuit 410 is released through the target power device.

[0070] In some embodiments of this disclosure, the generation unit 1106 may include a first obtaining unit, a first adjusting unit, and a duty cycle generation unit. The first obtaining unit is configured to obtain the current value of the feedback current flowing through the target power device in the inverter circuit. The first adjusting unit is configured to adjust the duty cycle of the pulse width modulation signal based on the target current value and the feedback current value. The duty cycle generation unit is configured to generate the pulse width modulation signal according to the adjusted duty cycle.

[0071] In some embodiments of this disclosure, the first adjustment unit includes a first determining unit and a second adjustment unit. The first determining unit is configured to determine a current difference between a target current value and a feedback current value. The second adjustment unit is configured to adjust the duty cycle of a pulse width modulation signal based on the current difference, wherein the duty cycle is proportional to the current difference.

[0072] In some embodiments of this disclosure, the first adjustment unit further includes a second determining unit, a third adjusting unit, and a fourth adjusting unit. The second determining unit is configured to determine whether the adjusted duty cycle is higher than an upper limit value or lower than a lower limit value. The third adjusting unit is configured to adjust the adjusted duty cycle to the upper limit value if the adjusted duty cycle is higher than the upper limit value. The fourth adjusting unit is configured to adjust the adjusted duty cycle to the lower limit value if the adjusted duty cycle is lower than the lower limit value.

[0073] In some embodiments of this disclosure, the first obtaining unit includes a plurality of obtaining sub-units and a third determining unit. Each obtaining sub-unit is configured to obtain the current value of the current flowing through the power device in a corresponding phase of the plurality of phases. The third determining unit is configured to determine the average current value of the current flowing through the power device in the plurality of phases as the current value of the feedback current.

[0074] In some embodiments of this disclosure, the generation unit 1106 further includes a second obtaining unit and a fourth determining unit. The second obtaining unit is configured to obtain the ambient temperature of the inverter circuit. The fourth determining unit is configured to determine a target current value based on the ambient temperature. The ambient temperature is inversely proportional to the target current value.

[0075] In some embodiments of this disclosure, the first control unit 1104 includes a first stop unit, a sending unit, and a fifth determining unit. The first stop unit is configured to stop generating drive control signals for controlling the normal operation of the inverter circuit. The sending unit is configured to send a shutdown request to the power supply controller. The shutdown request is used to control the disconnection of a relay between the inverter circuit and the power supply. The fifth determining unit is configured to determine that the connection between the inverter circuit and the power supply has been disconnected upon receiving a signal from the controller that the relay has been disconnected.

[0076] In some embodiments of this disclosure, the apparatus 1100 further includes a detection unit and a second stop unit. The detection unit is configured to detect the voltage value of the energy storage device. The second stop unit is configured to stop generating a pulse width modulation signal when the voltage value of the energy storage device is lower than a target voltage value.

[0077] Figure 12 A schematic block diagram of a controller 1200 suitable for implementing embodiments of the present disclosure is shown. For example, Figure 4 The DCU 421 in the code can be implemented using the controller 1200. For example... Figure 12 As shown, the controller 1200 includes a processor 1201, which can perform various appropriate actions and processes based on computer program instructions loaded into random access memory (RAM) 1203 according to computer program instructions stored in read-only memory (ROM) 1202. The RAM 1203 may also store various programs and data required for the operation of the controller 1200. The processor 1201, ROM 1202, and RAM 1203 are interconnected via a bus 1204. An input / output (I / O) interface 1205 is also connected to the bus 1204.

[0078] The various processes and procedures described above, such as method 300, can be executed by processor 1201. For example, in some embodiments, method 300 may be implemented as a software program tangibly contained in a machine-readable medium. In some embodiments, part or all of the software program may be loaded into and / or installed onto controller 1200 via ROM 1202. When the software program is loaded into RAM 1203 and executed by processor 1201, one or more actions of method 300 described above may be performed.

[0079] In summary, the method for controlling an inverter circuit according to embodiments of the present disclosure can utilize the target power device inside the inverter circuit to at least partially release the charge stored in the energy storage device during the power-down process of the inverter circuit, thereby meeting electrical safety requirements. This method does not require external hardware devices, thus saving hardware resources and costs. Similarly, the apparatus, controller, and inverter device for controlling an inverter circuit according to embodiments of the present disclosure also have the above advantages.

[0080] Unless otherwise expressly indicated by the context, the singular form of words used herein and in the appended claims includes the plural form, and vice versa. Thus, when referring to the singular, the plural form of the corresponding term is generally included. Where the term “example” is used herein, particularly when it follows a set of terms, the “example” is merely exemplary and illustrative and should not be considered exclusive or pervasive.

[0081] Further aspects and scope of adaptation become apparent from the description provided herein. It should be understood that various aspects of this application may be implemented individually or in combination with at least one other aspect. It should also be understood that the descriptions and specific embodiments herein are for illustrative purposes only and are not intended to limit the scope of this application.

[0082] The various embodiments of this disclosure have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or improvement of the technology in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. A method (300) for controlling an inverter circuit, comprising: In response to receiving a power-down request for the inverter circuit, control (302) disconnects the inverter circuit from the power supply; Generate a (304) pulse width modulation signal; as well as Control (306) to turn on the target power device in the inverter circuit according to the generated pulse width modulation signal, wherein during the turn-on of the target power device, the charge stored in the energy storage device in the inverter circuit is at least partially released through the target power device.

2. The method (300) according to claim 1, wherein the target power device includes a target power device located in one or more phases of the inverter circuit, and the target power device in each of the one or more phases includes at least one power device located in the upper half-bridge and at least one power device located in the lower half-bridge of that phase.

3. The method (300) according to claim 1 or 2, wherein generating (304) the pulse width modulation signal comprises: Obtain the current value of the feedback current flowing through the target power device in the inverter circuit; The duty cycle of the pulse width modulation signal is adjusted according to the target current value and the current value of the feedback current. as well as The pulse width modulation signal is generated according to the adjusted duty cycle.

4. The method (300) according to claim 3, wherein adjusting the duty cycle of the pulse width modulation signal based on the target current value and the current value of the feedback current comprises: Determine the current difference between the target current value and the feedback current value; as well as The duty cycle of the pulse width modulation signal is adjusted based on the current difference, wherein the duty cycle is proportional to the current difference.

5. The method (300) according to claim 4, wherein generating the (304) pulse width modulation signal further comprises: After adjusting the duty cycle of the pulse width modulation signal based on the current difference, Determine whether the adjusted duty cycle is higher than the upper limit or lower than the lower limit; In response to the adjusted duty cycle being higher than the upper limit value, the adjusted duty cycle is adjusted to the upper limit value; as well as In response to the adjusted duty cycle being lower than the lower limit, the adjusted duty cycle is adjusted to the lower limit.

6. The method (300) according to claim 3, wherein obtaining the current value of the feedback current flowing through the target power device in the inverter circuit comprises: When the target power device includes the target power device located in multiple phases of the inverter circuit, the current value of the current flowing through the target power device in each of the multiple phases is obtained, and the average current value of the current flowing through the power devices in the multiple phases is determined as the current value of the feedback current.

7. The method (300) according to claim 3, wherein generating the (304) pulse width modulation signal further comprises: Obtain the ambient temperature of the inverter circuit; as well as The target current value is determined based on the ambient temperature, wherein the ambient temperature is inversely proportional to the target current value.

8. The method (300) according to claim 1 or 2, wherein controlling (302) to disconnect the inverter circuit from the power supply comprises: Stop generating drive control signals used to control the normal operation of the inverter circuit; Send a shutdown request to the controller of the power supply, wherein the shutdown request is used to control the relay between the inverter circuit and the power supply to disconnect; and In response to receiving a signal from the controller that the relay has been disconnected, it is determined that the connection between the inverter circuit and the power supply has been broken.

9. The method (300) according to claim 1 or 2, further comprising: Detect the voltage value of the energy storage device; as well as In response to the voltage value of the energy storage device being lower than the target voltage value, the generation of the pulse width modulation signal is stopped.

10. A device (1100) for controlling an inverter circuit, comprising: A receiving unit (1102) is configured to receive a power-down request for the inverter circuit; A first control unit (1104) is configured to control the disconnection of the inverter circuit from the power supply; The generation unit (1106) is configured to generate a pulse width modulation signal; as well as A second control unit (1108) is configured to control a target power device in the inverter circuit to be turned on according to a generated pulse width modulation signal, wherein during the turn-on of the target power device, the charge stored in the energy storage device in the inverter circuit is at least partially released through the target power device.

11. A controller (1200), comprising: At least one processor; as well as A memory coupled to the at least one processor and having instructions stored thereon, which, when executed by the at least one processor, cause the controller to perform the method (300) according to any one of claims 1-9.

12. An inverter device (200), comprising: Inverter circuit, which includes power devices and energy storage devices; as well as The controller (1200) according to claim 11.

13. The inverter device (200) according to claim 12, wherein the inverter circuit further comprises: Current detection circuit The current detection circuit includes: A current acquisition circuit is configured to acquire the feedback current flowing through the target power device in the inverter circuit; A first analog-to-digital converter circuit is configured to perform analog-to-digital conversion on the feedback current to obtain the current value of the feedback current.

14. The inverter device (200) according to claim 12, wherein the inverter circuit further comprises: Voltage detection circuit, The voltage detection circuit includes: A first resistor is connected in series with the target power device; An operational amplifier, wherein a first input terminal of the operational amplifier is coupled to a first terminal of the first resistor, and a second input terminal of the operational amplifier is coupled to a second terminal of the first resistor; A first analog-to-digital converter circuit, wherein the first analog-to-digital converter circuit is coupled to the output of the operational amplifier and configured to perform analog-to-digital conversion on the feedback voltage output from the output of the operational amplifier to obtain the voltage value of the feedback voltage; The instructions, when executed by the at least one processor, cause the controller to also determine the current value of the feedback current flowing through the target power device in the inverter circuit based on the voltage value of the feedback voltage and the resistance value of the first resistor.

15. The inverter device (200) according to any one of claims 12 to 14, further comprising: Temperature detection circuit, The temperature detection circuit includes: A second resistor, wherein a first end of the second resistor is coupled to a first voltage terminal, and a second end of the second resistor is coupled to a first node; A thermistor, wherein a first end of the thermistor is coupled to the first node, and a second end of the thermistor is coupled to a second voltage terminal. The second analog-to-digital converter circuit is configured to perform analog-to-digital conversion on the voltage difference between the first and second terminals of the thermistor to obtain a reference voltage value. The instructions, when executed by the at least one processor, cause the controller to also determine the ambient temperature of the inverter circuit based on the reference voltage value.

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