Method, device and medium for controlling a converter unit of a vehicle

Abstract

The invention relates to a method, a device and a medium for controlling a converter unit of a vehicle. The converter unit includes a power interface, a motor interface, at least one H-bridge, and at least one snubber capacitor. The H-bridge and the at least one snubber capacitor are electrically interposed between the power interface and the motor interface. A switch is disposed on each branch of the H-bridge. The method includes closing a pair of switches for supplying current to the motor interface during a first predetermined time span. The method further includes, during a second predetermined time span and after the predetermined latency, closing the pair of switches to supply an induced current to the motor interface. The first predetermined time span and the second predetermined time span are associated with the same current supply half cycle. In addition, the present disclosure relates to a data processing device, a computer program, and a computer-readable storage medium.

Description

Technical Field

[0001] This invention relates to a method for using a converter unit for controlling a motor in a vehicle. The converter unit includes an H-bridge, wherein switches are disposed on each branch of the H-bridge.

[0002] Furthermore, this disclosure relates to data processing apparatus, computer programs, and computer-readable storage media for performing this method.

[0003] Furthermore, the present invention relates to a converter unit for a motor for a vehicle, a drive assembly for a vehicle including the converter unit, and a vehicle including the drive assembly. Background Technology

[0004] A converter unit for a vehicle's motor converts direct current (DC) supplied by the vehicle's power source (such as a traction battery) into alternating current (AC) supplied to the motor. Using the converter unit, the phase and amplitude of the AC power can be adjusted, allowing the motor to operate at a specific speed and / or provide a specific torque. Sometimes, this converter unit is also called an inverter unit.

[0005] To do this, the converter unit may include one or more H-bridges, with switches positioned on each branch of the H-bridge. The actual conversion from DC to AC is achieved by operating these switches in a coordinated manner. It is known that each operation of the switches introduces so-called switching losses. Summary of the Invention

[0006] Therefore, it may be necessary to improve the energy efficiency of this converter unit. In other words, it may be necessary to reduce switching losses.

[0007] The problem is at least partially solved or mitigated by the subject matter of the independent claims of this disclosure, wherein further examples are incorporated in the dependent claims.

[0008] According to a first aspect, a method is provided for a converter unit for controlling a motor in a vehicle. The converter unit includes a power interface, a motor interface, at least one H-bridge, and at least one buffer capacitor. The H-bridge and at least one buffer capacitor are electrically inserted between the power interface and the motor interface. Switches are provided on each branch of the H-bridge. The method includes:

[0009] - During a first predetermined time span, a pair of switches are closed to supply current to the motor interface, and

[0010] - During the second predetermined time span and after a predetermined waiting time, a pair of switches are closed to supply induced current to the motor interface.

[0011] The first predetermined time span and the second predetermined time span are associated with the same current supply half-cycle.

[0012] A power interface can be connected to the vehicle's power source. The power source can be the vehicle's traction battery. A motor interface can be connected to the vehicle's motor. The vehicle's motor can be a machine driven to at least one wheel of the vehicle. Therefore, the motor can be used to drive the vehicle. At least one buffer capacitor is electrically connected in parallel with at least one H-bridge. By alternately opening and closing the switch pair of at least one H-bridge, electrical energy from the power source supplied to the converter unit via the power interface can be converted from DC to AC. AC can be supplied to the vehicle's motor via the motor interface of the converter unit. During a first predetermined time span, a pair of switches (also referred to as the first pair of switches) is closed to supply current to the motor interface. Therefore, current can be supplied to the motor that can be connected to the motor interface. After the first predetermined time span, the first pair of switches is opened to interrupt the current supply to the motor interface. From this time onward, the magnetic field generated around the electrical conductors of the converter unit and / or the motor that can be connected to the motor interface of the converter unit begins to collapse. The changing magnetic field around the electrical conductors induces reactive voltage in the converter unit, particularly at the open switch of the converter unit. At least one buffer capacitor is in place to be charged by the reactive voltage, thereby mitigating the reactive voltage acting on the open switch. Therefore, at least one buffer capacitor effectively acts as a buffer or damper for the induced energy stored in the conductors of the converter unit and / or the motor that can be connected to the motor interface. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit from excessive reactive voltage. The buffer capacitor is thus charged. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which were opened at the end of a first predetermined time span after a predetermined waiting time, are closed again for a second predetermined time span. This has the effect that the energy stored in at least one buffer capacitor in the form of capacitive energy is provided to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor can be provided to the motor that can be connected to the motor interface. As a result, the inductive energy stored in the conductors of the converter unit and / or the conductors of the motor that can be connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy, which can be used to power the vehicle's motor, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the provision of capacitive energy to the motor interface. Furthermore, closing this pair of switches during the second time span to provide capacitive energy to the motor may have the effect that the relatively small capacitance of the buffer capacitor may be sufficient to buffer or suppress voltage peaks. It should be understood that during the execution of the above method, the other pair of switches (also referred to as the second pair of switches) of the H-bridge of the converter unit is permanently open, i.e., not closed. Therefore, the above method is applied to one half-cycle of current supply for a single phase of the motor.The current supply half-cycle is understood as part of the full cycle of AC supplied to the motor interface, during which the direction of the supplied current does not change. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0013] In the example, the converter unit includes multiple H-bridges connected in parallel with each other. Each first pair of switches in the multiple H-bridges can be operated sequentially, such that each first pair of switches in each H-bridge is continuously closed until all first pairs of switches are closed. Similarly, each first pair of switches in the multiple H-bridges can be operated sequentially, such that each first pair of switches is continuously open until all first pairs of switches are open again. This allows for an approximation of the sinusoidal voltage curve provided to the motor interface. It should be understood that the method according to this disclosure can be applied to each of the multiple H-bridges in the converter unit. Therefore, the process of closing the first pair of switches of a particular H-bridge after a predetermined waiting time in a second predetermined time span can be repeated for each H-bridge after its first pair of switches has ended in the first predetermined time span. This has the effect of minimizing energy loss at the end of each approximation step of the sinusoidal voltage curve. Therefore, at the end of the first predetermined time span of each approximation step, induced energy can be provided to the motor interface during the second predetermined time span to power a motor that can be connected to the motor interface.

[0014] In the example, the second time span and the waiting time are very small compared to the first time span. In the example, the second time span and / or the waiting time is less than 10% of the first time span. In another example, the second time span and / or the waiting time is less than 1% of the first time span. This has the following effect: during the first predetermined time span, a sufficient amount of primary energy supplied by the power source via the power interface can be provided to the motor interface. Therefore, the motor of a vehicle that can be connected to the motor interface can be powered by a sufficient amount of primary energy to drive the vehicle. The induced energy regained to power the motor can be referred to as secondary energy. Because the amount of secondary energy is small compared to the amount of primary energy, the very small second time span and the waiting time compared to the first time span are sufficient to discharge the secondary energy to the motor that can be connected to the motor interface.

[0015] In the example, the second time span and / or the latency is fixed. In other words, the second time span and the latency can each be constant. Providing a fixed second time span and a fixed latency has the effect of enabling efficient and easy-to-implement control of the converter unit. It should be understood that the second time span and / or latency are adapted to specific implementations to achieve the desired improvement in energy efficiency.

[0016] In the example, the predetermined waiting time and / or second time span are based on the inductance of the converter unit and the capacitance of at least one buffer capacitor. The underlying concept is that the inductance of the converter unit and the capacitance of the buffer capacitor form an oscillating circuit, in other words, a resonant circuit. The resonant frequency f0 of the oscillating circuit can be obtained by formula... Here, L represents the inductance of the converter unit (in Henry), and C represents the capacitance of the buffer capacitor (in Farads). Therefore, the duration d0 of the oscillation circuit can be determined by the formula... Definitely. The predetermined waiting time and / or second time span can be defined as a percentage of the time period duration d0. This has the effect that the predetermined waiting time and / or second time span are suitable for the electrical characteristics of the converter unit. This can further improve the energy efficiency of the converter unit. This is especially true if the capacitance of the inductor and buffer capacitor of the converter unit changes over time, for example, due to an aging process.

[0017] In the example, the predefined waiting time can be set to 15% to 50% of the time period duration d0, for example, 25%. After this waiting time, it is expected that at least one buffer capacitor will be fully charged. Therefore, after the corresponding switch has been open for the waiting time, the first pair of switches is closed to supply the electrical energy stored in at least one buffer capacitor to the motor interface. The maximum amount of capacitive energy stored in at least one buffer capacitor can be used to power the vehicle's motor. This results in very high energy efficiency.

[0018] In the example, the sum of the predetermined waiting time and the second time span can be set to 15% to 50% of the time period duration d0, for example, 25%. After the waiting time and the second time span have elapsed, the maximum induced energy stored in the converter unit is expected to be available for conversion and / or recovery to power the vehicle's motor. Therefore, after the waiting time and the second time span, closing the first pair of switches to supply the electrical energy stored in at least one buffer capacitor to the motor interface allows the maximum amount of induced energy stored in the converter unit to be converted and / or recovered to power the vehicle's motor.

[0019] In the example, the second time span can be defined as a percentage of the scheduled wait time and / or a percentage of the sum of the scheduled wait time and the second time span. This is a simple and reliable way to set the second time span.

[0020] In another example, the second time span can be defined based on the capacitance of at least one buffer capacitor. The time span t during which the capacitor discharges half of its capacitive charge. H Usually derived from formula t H=RC ln(2) is defined, where R represents the resistance to capacitor discharge (in ohms) and C represents the capacitance of the buffer capacitor (in farads). Therefore, based on the capacitance of at least one buffer capacitor, the second time span is defined as the time period t. H The percentage or multiple has the following effect: a predetermined percentage of energy that has been converted from inductive energy to capacitive energy can be regained to power the vehicle's motor. Specifically, the second time span is defined as the time period t. H The percentage or multiple ensures that the minimum percentage of energy that has been converted from inductive energy to capacitive energy can be regained to power the vehicle's motor.

[0021] In the example, the method also includes optimizing a second time span and / or a latency. Optimization of the second time span and / or latency may be necessary because the capacitance C of at least one buffer capacitor or the inductance L of the converter unit may not be precisely known. Additionally or alternatively, the capacitance C of at least one buffer capacitor or the inductance L of the converter unit may vary over time, for example, due to aging processes. Specifically, the capacitance C of at least one buffer capacitor and / or the inductance L of the converter unit may decrease with the vehicle's lifespan. Therefore, the latency and / or second time span already defined with respect to the nominal values ​​of capacitance C and inductance L may not contribute to the optimal switching time of the H-bridge's switching pairs. In other words, the latency and / or second time span defined with respect to the nominal values ​​of capacitance C and inductance L may not produce the optimal amount of inductive energy converted into capacitive energy and used to power the vehicle's motor. Furthermore, the optimized second time span and / or latency has the effect that the maximum amount of induced energy stored in the converter unit can be converted into capacitive energy, which can then be used to power the vehicle's motor. Optimization may include machine learning techniques, particularly reinforcement learning.

[0022] Note that the purpose of optimizing the second time span and / or waiting time could be to provide maximum charging at the motor interface during the second time span. This goes back to optimization to provide maximum electrical energy at the motor interface during the second time span.

[0023] In the example, the method also includes:

[0024] - Obtain first data indicating the amount of capacitive energy stored in at least one buffer capacitor, and

[0025] - Adjust the waiting time and / or the second time span based on the first data.

[0026] Obtaining the first data can be understood as receiving or determining first data indicating the amount of capacitive energy stored in at least one buffer capacitor. The first data may, for example, include the voltage across the buffer capacitor. The capacitive energy E stored in at least one buffer capacitor... C The quantity can be expressed by the formula The voltage across at least one buffer capacitor is derived, where U represents the voltage across at least one buffer capacitor (in volts). If the capacitive energy E stored in at least one buffer capacitor... C If the amount of energy decreases before the end of the waiting time, it may be necessary to shorten the waiting time. This has the following effect: preventing the stored capacitive energy E from being released during the waiting time. C A portion is supplied to a power source that can be connected to a power interface. Capacitive energy E is provided to the vehicle's power supply. C In other words, through the stored capacitor energy E C A portion of the energy used to charge the vehicle's electrical system is equivalent to directly using the stored capacitor energy E. C Powering the vehicle's motor results in greater energy loss. If the capacitive energy E stored in at least one buffer capacitor at the end of the waiting time... C The amount is the maximum capacitor energy E during the waiting time. C If the amount is too large, the waiting time may need to be extended. This has the following effect: it avoids converting only a portion of the inductor energy stored in the converter unit into capacitor energy before the first pair of switches is closed again. In other words, it ensures that the capacitor energy E stored in at least one buffer capacitor is... C The system stabilizes at the end of the waiting period. Therefore, the efficiency of the converter unit can be improved, and energy loss can be minimized. Furthermore, the second time span can be adjusted based on the first data, ensuring that the capacitor has discharged its maximum stored capacitance energy E within the second time span. C The predetermined minimum percentage. If the capacitor energy E C If the discharge rate is below the minimum percentage, a second time span may need to be extended. If the capacitor energy E C If the discharge rate is higher than the minimum percentage, the second time span may remain unchanged or may need to be shortened. In summary, obtaining the first data and adjusting the waiting time and / or second time span based on it results in a waiting time and / or second time span suitable for improved energy efficiency.

[0027] In the example, the method also includes:

[0028] - Obtain second data indicating the current at the power interface measured after the first time span, and

[0029] - Adjust the waiting time and / or the second time span based on the second data.

[0030] Obtaining the second data can be understood as receiving or determining second data indicating the current at the power interface measured after the first time span. If current flows back to the power supply from the converter unit via the power interface during the waiting time, it may be necessary to shorten the waiting time. This is particularly likely to occur due to the capacitive energy E stored in at least one buffer capacitor. C The amount decreases before the waiting time ends. In this scenario, shortening the waiting time has the effect of avoiding energy loss due to charging by a power source connected to the power interface. If current flows back to the power source from the converter unit via the power interface after the second time span, it may be necessary to extend the second time span. This scenario indicates that the second time span is insufficient to discharge the capacitive energy E stored in at least one buffer capacitor by providing the energy to the motor interface. C Therefore, extending the second time span in the described scenario ensures that the capacitive energy stored in at least one buffer capacitor is used to power the vehicle's motor. If current flows from the power supply to the converter unit via the power interface during the second time span, it may be necessary to shorten the second time span. This avoids the loss of capacitive energy E stored in at least one buffer capacitor. C The additional electrical energy is supplied to the motor interface and is therefore used to power the vehicle's motor during the second time span. In summary, obtaining the second data and adjusting the waiting time and / or the second time span based on it results in a waiting time and / or second time span suitable for improved energy efficiency.

[0031] It should be understood that the extension and shortening of the time span explained above can be achieved using incremental steps. The size of the incremental step can be predetermined. Alternatively, the size of the incremental step can be increased when the obtained parameters (i.e., the first data and / or the second data) deviate from the expected reference value by a greater margin than allowed and / or considered acceptable. This has the effect of effectively modifying the waiting time and the second time span, thereby minimizing energy loss.

[0032] The methods disclosed herein can be implemented, at least in part, by a computer, and can be implemented in software or hardware, or both. Furthermore, the methods can be executed by computer program instructions running on a component providing data processing functionality. The data processing component can be a suitable computing component (such as an electronic control module), or it can be a distributed computer system. The data processing component or the computer can each include one or more of a processor, memory, data storage device, or a combination thereof.

[0033] According to a second aspect, a data processing apparatus is provided, comprising components for performing the method of the first aspect. Using this data processing apparatus, a converter unit for a motor in a vehicle can be reliably controlled. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in a motor that can be connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit against excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been open at the end of a first predetermined time span after a predetermined waiting time, are closed again for a second predetermined time span. This has the effect that the energy stored in at least one buffer capacitor in the form of capacitive energy is supplied to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor can be supplied to the motor that can be connected to the motor interface. As a result, the inductive energy stored in the electrical conductors of the converter unit and / or in the electrical conductors of the motor that can be connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy, which can be used to power the motor of the vehicle, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor interface. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0034] In the example, the data processing device includes a distributed data processing unit comprising a first subunit and a second subunit. The first subunit is communicatively connected to a switch of the H-bridge of the converter unit. The second subunit is communicatively connected to a first sensing unit for providing first data indicating capacitive energy stored in a buffer capacitor and / or communicatively connected to a second sensing unit for providing second data indicating current at a power interface. The first and second subunits can be communicatively connected to each other via a wired connection. A wired connection is a reliable way to exchange data between the subunits of the data processing device with minimal signal interference. Additionally or alternatively, the first and second subunits can be connected to each other via a wireless connection (such as Bluetooth, particularly Bluetooth Low Latency, and / or Wi-Fi). Wireless connectivity between the subunits of the data processing device simplifies manufacturability because no cabling is required during the installation of the subunits of the data processing device in a vehicle.

[0035] According to a third aspect, a computer program including instructions is provided, which, when executed by a computer, cause the computer to perform the method of the first aspect. Using such a computer program, a converter unit for a motor in a vehicle can be reliably controlled. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in a motor that can be connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit against excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been open at the end of a first predetermined time span, are closed again for a second predetermined time span after a predetermined waiting time. This has the effect that the energy stored in at least one buffer capacitor in the form of capacitive energy is provided to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor can be provided to the motor that can be connected to the motor interface. As a result, the inductive energy stored in the electrical conductors of the converter unit and / or in the electrical conductors of the motor that can be connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy, which can be used to power the motor of the vehicle, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor interface. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0036] According to a fourth aspect, a computer-readable storage medium including instructions is provided, which, when executed by a computer, cause the computer to perform the method of the first aspect. Using this computer-readable storage medium, a converter unit for a motor in a vehicle can be reliably controlled. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in a motor that can be connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit against excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been open at the end of a first predetermined time span after a predetermined waiting time, are closed again for a second predetermined time span. This has the effect that the energy stored in at least one buffer capacitor in the form of capacitive energy is provided to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor can be provided to the motor that can be connected to the motor interface. As a result, the inductive energy stored in the electrical conductors of the converter unit and / or in the electrical conductors of the motor that can be connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy that can be used to power the motor of the vehicle, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor interface. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0037] According to a fifth aspect, a converter unit for a motor in a vehicle is provided. The converter unit includes:

[0038] - Power connector for connection to a power source.

[0039] - Motor interface that can be connected to the motor.

[0040] - At least one H-bridge, wherein a switch is provided on each branch of the H-bridge.

[0041] - At least one buffer capacitor, and

[0042] - According to the data processing device of the second aspect.

[0043] The H-bridge and at least one buffer capacitor are electrically inserted between the power interface and the motor interface. The data processing unit is communicatively connected to the switch of the H-bridge.

[0044] The power source can be the vehicle's traction battery. The vehicle's motor can be a machine driven by at least one wheel of the vehicle. Therefore, the motor can be used to drive the vehicle. At least one buffer capacitor is electrically connected in parallel with at least one H-bridge. By alternately opening and closing the switch pair of at least one H-bridge, electrical energy from the power source supplied to the converter unit via the power interface can be converted from direct current (DC) to alternating current (AC). AC can be supplied to the vehicle's motor via the motor interface of the converter unit. Due to the data processing equipment, the converter unit for the vehicle's motor can be reliably controlled. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in the motor that can be connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the converter unit's switches from excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been opened at the end of a first predetermined time span, is closed again for a second predetermined time span after a predetermined waiting time. This has the effect that the energy stored in at least one buffer capacitor in the form of capacitive energy is supplied to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor can be supplied to the motor that can be connected to the motor interface. As a result, the inductive energy stored in the conductors of the converter unit and / or the conductors of the motor that can be connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy, which can be used to power the vehicle's motor, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor interface. In summary, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0045] In one example, the converter unit further includes a first sensing unit for providing first data indicating the amount of capacitive energy stored in the buffer capacitor. The first data may, for example, include the voltage across the buffer capacitor. Therefore, the first sensing unit may be a voltmeter. The capacitive energy E stored in at least one buffer capacitor... C The quantity can be expressed by the formula The voltage is derived from at least one buffer capacitor, where U represents the voltage across the at least one buffer capacitor (in volts). Based on first data provided by the first sensing unit, the waiting time and / or a second time span can be adjusted. If the capacitive energy E stored in the at least one buffer capacitor... C If the amount of energy decreases before the waiting time ends, the data processing device may need to shorten the waiting time. This has the following effect: avoiding the loss of stored capacitive energy E. CA portion is supplied to a power source that can be connected to a power interface. Capacitive energy E is provided to the vehicle's power supply. C In other words, through the stored capacitor energy E C A portion of the energy used to charge the vehicle's electrical system is equivalent to directly using the stored capacitor energy E. C Powering the vehicle's motor results in greater energy loss. If the capacitive energy E stored in at least one buffer capacitor at the end of the waiting time... C The amount is the maximum capacitor energy E during the waiting time. C The amount of energy stored in the converter unit may require an extended waiting time due to the data processing device. This has the following effect: it avoids converting only a portion of the inductor energy stored in the converter unit into capacitor energy before the switch pair is closed again. In other words, it ensures that the capacitor energy E stored in at least one buffer capacitor is... C The system stabilizes at the end of the waiting period. Therefore, the efficiency of the converter unit can be improved, and energy loss can be minimized. The second time span can be adjusted based on the first data, ensuring that the capacitor has discharged its maximum stored capacitance energy E within the second time span. C The predetermined minimum percentage. If the capacitor energy E C If the discharge amount is below the minimum percentage, a second time span may need to be extended by the data processing device. If the capacitor energy E C If the discharge amount is higher than the minimum percentage, the second time span may remain unchanged or may need to be shortened by the data processing device. In summary, adjusting the waiting time and / or the second time span based on the first data provided by the first sensing unit results in a waiting time and / or the second time span suitable for improved energy efficiency.

[0046] In the example, the converter unit also includes a second sensing unit for providing second data indicating the current at the power interface. The second data may, for example, include a measurement of the current flowing through the power interface. Therefore, the second sensing unit can be a shunt, in other words, a low-impedance resistor connected in parallel with a voltmeter of the measuring device. The advantage of using a shunt is that relatively high currents can be reliably measured because only a small fraction of the current actually flows through the measuring device. Based on the second data provided by the second sensing unit, the waiting time and / or a second time span can be adjusted. If the current flows back to the power supply via the power interface during the waiting time, it may be necessary to shorten the waiting time by a data processing device. This may be particularly relevant to the capacitive energy E stored in at least one buffer capacitor. CThe amount decreases consistently before the waiting time ends. Shortening the waiting time in this scenario has the effect of avoiding energy loss due to charging the power supply. If the current flows back to the power supply via the power interface after the second time span, it may be necessary for the data processing device to extend the second time span. This scenario indicates that the second time span is insufficient to discharge the capacitive energy E stored in at least one buffer capacitor by providing the energy to the motor interface. C Therefore, extending the second time span in the described scenario ensures that the capacitive energy stored in at least one buffer capacitor is used to power the vehicle's motor. If current flows from the power source into the converter unit via the power interface during the second time span, it may be necessary for the data processing device to shorten the second time span. This avoids the loss of capacitive energy E stored in at least one buffer capacitor. C The additional electrical energy is supplied to the motor interface and thus used to power the vehicle's motor. In summary, the waiting time and / or the second time span can be adjusted based on the second data. This results in a waiting time and / or a second time span suitable for improved energy efficiency.

[0047] According to a sixth aspect, a drive assembly for a vehicle is provided, comprising a converter unit and a motor according to a fifth aspect. The motor is electrically coupled to a motor interface of the converter unit. This drive assembly allows for reliable control of the converter unit for an electric vehicle. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in the motor connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit against excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been open at the end of a first predetermined time span, are closed again for a second predetermined time span after a predetermined waiting time. This has the effect that the energy stored in at least one buffer capacitor as capacitive energy is supplied to the motor interface. Therefore, the capacitive energy stored in at least one buffer capacitor is supplied to the motor connected to the motor interface. As a result, the inductive energy stored in the electrical conductors of the converter unit and / or in the electrical conductors of the motor connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy, which can be used to power the motor of the vehicle, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor via the motor interface. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0048] According to a seventh aspect, a vehicle is provided that includes the drive assembly of the sixth aspect. Such a vehicle provides a converter unit that can be reliably controlled. Specifically, at least one buffer capacitor of the converter unit effectively acts as a buffer or damper for the inductive energy stored in the electrical conductors of the converter unit and / or in the motor connected to the motor interface of the converter unit. In other words, at least one buffer capacitor serves as a protection for the switching of the converter unit against excessive reactive voltage. After at least one buffer capacitor has been charged by reactive voltage, the same pair of switches, which had been open at the end of a first predetermined time span after a predetermined waiting time, closes again for a second predetermined time span. This has the effect that the energy stored in the at least one buffer capacitor as capacitive energy is supplied to the motor interface. Therefore, the capacitive energy stored in the at least one buffer capacitor is supplied to the motor connected to the motor interface. As a result, the inductive energy stored in the electrical conductors of the converter unit and / or in the electrical conductors of the motor connected to the motor interface (which would otherwise be lost, for example, through heat dissipation) is converted into capacitive energy that can be used to power the motor of the vehicle, in other words, to drive the vehicle. In other words, at least one buffer capacitor acts as a temporary storage device for said energy during the conversion from inductive energy to capacitive energy and during the supply of capacitive energy to the motor via the motor interface. In short, the induced energy generated by the opening of the switch pair is used to drive the motor instead of being lost. This improves energy efficiency.

[0049] It should be noted that the above examples can be combined with each other, regardless of the aspects involved.

[0050] These and other aspects of this disclosure will become apparent from the examples described below and will be illustrated with reference to the examples described below. Attached Figure Description

[0051] Examples of this disclosure will now be described with reference to the following figures.

[0052] Figure 1 A vehicle according to the invention is shown, the vehicle including a drive assembly according to the invention, wherein the drive assembly includes a converter unit according to the invention.

[0053] Figure 2 schematically shown Figure 1 The vehicle's drive components,

[0054] Figure 3 It shows the supply to Figure 1 A schematic diagram of the step voltage signal of the vehicle's motor.

[0055] Figure 4 It shows Figure 3 Details of the voltage diagram, IV.

[0056] Figure 5 A schematic diagram is shown illustrating the amount of capacitive energy stored in the buffer capacitor of the converter unit according to the invention during the waiting time and a second predetermined time span.

[0057] Figure 6 A schematic diagram is shown showing the amount of capacitive energy stored in the buffer capacitor of the converter unit according to the present invention during a first predetermined time span, a waiting time, a second predetermined time span, and a time period following the second predetermined time span.

[0058] Figure 7 This shows the flow from the converter unit during the waiting time. Figure 1 A schematic diagram of the current in the vehicle's power supply.

[0059] Figure 8 It shows the flow from the converter unit after the second time span. Figure 1 A schematic diagram of the vehicle's power supply current, and

[0060] Figure 9 It shows the flow from the power source during the second time span. Figure 1 A schematic diagram of the current in the converter unit of the vehicle. Detailed Implementation

[0061] The accompanying drawings are merely illustrative and are intended to illustrate examples of this disclosure only. Identical or equivalent elements are generally provided with the same reference numerals.

[0062] Figure 1 Vehicle 10 is shown.

[0063] The vehicle 10 includes a drive assembly 12. The drive assembly 12 may also be referred to as the powertrain of the vehicle 10.

[0064] The drive assembly 12 includes a traction battery 14 forming a power source 16, a converter unit 18, and a motor 20.

[0065] The converter unit 18 is electrically inserted between the traction battery 14 and the motor 20. Therefore, the converter unit 18 can convert the DC power from the traction battery 14 into AC power supplied to the motor 20. Using the converter unit 18, the phase and amplitude of the AC power can be adjusted so that the motor 20 can operate at a certain speed and / or provide a certain torque.

[0066] In this example, motor 20 is drivenly connected to the front wheel 22 of vehicle 10. Therefore, motor 20 drives the front axle of vehicle 10. It should be understood that motor 20 may be additionally or alternatively connected to any other wheel of vehicle 10, such as the rear wheel of the rear axle.

[0067] Details of converter unit 18 are in Figure 2 As shown in the image.

[0068] The converter unit 18 includes a power interface 24, which is electrically connected to the traction battery 14.

[0069] The converter unit 18 also includes a motor interface 26, which is electrically connected to the motor 20 that drives the front axle of the vehicle 10.

[0070] In addition, converter unit 18 includes H-bridge 28.

[0071] At each branch of H-bridge 28, switches SW1, SW2, SW3, and SW4 are installed to interrupt or establish electrical connections to and from H-bridge 28. Figure 2 In the diagram, the switches are represented by SW1, SW2, SW3, and SW4.

[0072] Switches SW1, SW2, SW3, and SW4 can operate in a coordinated manner, converting the DC power supplied by the traction battery 14 into AC power for the motor 20. For this purpose, switches SW1 and SW4 form the first pair of switches. Switches SW1 and SW4 are always simultaneously open or closed. Switches SW2 and SW3 form the second pair of switches. Furthermore, switches SW2 and SW3 are always simultaneously open or closed.

[0073] The switches of the first pair of switches SW1 and SW4 and the second pair of switches SW2 and SW3 are opened or closed alternately. This means that if one pair of switches is closed, that is, if both switches in the pair are closed, then the corresponding other pair of switches is open, that is, both switches in the corresponding other pair are open.

[0074] If two of the switches in a pair are closed, they are connected in series with each other and in series with the electrical phase of the motor 20 of the vehicle 10. Therefore, by closing the pair of switches, the current supplied by the traction battery 14 is supplied to the motor 20 in the first direction via one phase.

[0075] If two switches in one pair are open, two switches in the other pair are closed. Due to the cross arrangement of the two pairs of switches, the closing of the other pair causes the current supplied by the traction battery 14 to be supplied to the motor 20 in a second direction opposite to the first direction through a phase. Because the first and second directions of the current supplied to the motor 20 are opposite to each other, the converter unit 18 can provide AC to the motor 20.

[0076] The converter unit 18 can not only provide the motor 20 with a given voltage level, both positive and negative. Instead, the converter unit 18 can also provide the motor 20 with a time-varying stepped voltage profile. This stepped voltage profile can include both positive and negative voltages.

[0077] The step voltage curve resembles a sine curve. This is in Figure 3 As shown in the image.

[0078] For this purpose, converter unit 18 includes multiple H-bridges 28 electrically connected in parallel with each other. Figure 3 In the example, the converter unit comprises seven H-bridges 28 connected in parallel. This can be seen from... Figure 3 The step approximation of the sinusoidal voltage curve can be seen in the schematic diagram. It should be understood that in practical applications, there may be far more than seven H-bridges to achieve an approximation of the sinusoidal curve of the voltage supplied to motor 20. Figure 3 The approximation of the sine curve by seven steps is for illustrative purposes only.

[0079] Each of the multiple H-bridges 28 includes a resistor 30. By selecting and / or adjusting the resistance value of the resistor 30 in each H-bridge 28, a specific percentage of the voltage across the traction battery 14 is supplied to the motor 20.

[0080] If multiple H-bridges 28 are turned on due to the closure of their respective first or second pair of switches, the resistors 30 of the multiple conductive H-bridges 28 are connected in parallel, resulting in a high percentage voltage being supplied to the motor 20 across the traction battery 14.

[0081] If a few H-bridges in H-bridge 28 are turned on due to the closure of their respective first or second pair of switches, then the resistors 30 of only a few turned H-bridges are connected in parallel, resulting in a low percentage of voltage across the traction battery 14 being supplied to the motor 20.

[0082] The converter unit 18 also includes a data processing device 32. The data processing device 32 is configured to switch the switches SW1, SW2, SW3, and SW4 of the H-bridge 28. In other words, the data processing device 32 controls the switches SW1, SW2, SW3, and SW4 of the H-bridge 28. Therefore, the data processing device 32 can also be referred to as a control unit.

[0083] For this purpose, the data processing device 32 is communicatively connected to switches SW1, SW2, SW3, and SW4 of the H-bridge 28.

[0084] The data processing device 32 includes a data storage unit 34 and a data processing unit 36.

[0085] The data storage unit 34 includes a computer-readable storage medium 38.

[0086] A computer program 40 is provided on a computer-readable storage medium 38.

[0087] The computer program 40 and therefore the computer-readable storage medium 38 include instructions that, when executed by the data processing unit 36 ​​or more generally the computer, cause the computer or the data processing unit 36 ​​to perform a method for controlling the converter unit 18 of the motor 20 of the vehicle 10.

[0088] Therefore, the data storage unit 34 and the data processing unit 36 ​​form an apparatus 42 for performing a method for controlling the converter unit 18 of the motor 20 of the vehicle 10.

[0089] In the following text, Figure 3 and Figure 4 The steps of the method are explained in the example of the sixth step of the stepwise approximation of the sinusoidal voltage curve shown. Figure 3 In the diagram, the approximate sixth step starts counting along the positive y-axis from the x-axis.

[0090] In step S1, the first pair of switches (i.e., switches SW1 and SW4) of the H-bridge 28 in the sixth approximate step are closed for a first predetermined time span FT. Therefore, current is supplied to the motor 18 connected to the motor interface 26.

[0091] Meanwhile, during the first predetermined time span FT, the second pair of switches (i.e. switches SW2 and SW3) of the H-bridge 28 in the sixth approximate step remain open.

[0092] The duration of the first pair of switches disconnected waiting time WT after the first predetermined time span FT.

[0093] During the waiting time WT, the magnetic field generated around the electrical conductors of converter unit 18 gradually collapses. This gradual collapse of the magnetic field represents a change in the magnetic field around the electrical conductors of converter unit 18. Consequently, a reactive voltage is generated in the electrical conductors of converter unit 18. This can be referred to as the release of induced energy stored in converter unit 18.

[0094] As a symbol for the inductance of converter unit 18, in Figure 2 The text indicates the induced charge 44. It should be emphasized that the converter unit 18 itself does not include dedicated components (such as the coils constituting the induced charge 44). In practice, the electrical connections of the converter unit 18 (e.g., wires) constitute the induced charge 44. Due to the strong current of approximately 1000 A supplied to the motor 20 by the converter unit 18, even a simple electrical connection like the wires of the converter unit 18 can serve as the induced charge 44.

[0095] To protect the switches SW1, SW2, SW3, and SW4 of the H-bridge 28 from excessive reactive voltage, the converter unit 18 also includes a buffer capacitor 46. The buffer capacitor 46 is connected in parallel with the traction battery 14 and in parallel with the H-bridge 28.

[0096] When a pair of switches SW1, SW2, SW3, and SW4 of the H-bridge 28 are disconnected during a waiting time WT following a first predetermined time span FT, the buffer capacitor 46 acts as a buffer or damper for the reactive voltage generated in the conductors of the converter unit 18. In other words, the waiting time WT is directly continuous with the first predetermined time span FT. The buffer operates by charging the buffer capacitor 46 with the generated reactive voltage. Therefore, during the waiting time WT, the inductive energy stored in the converter unit 18 is converted into capacitive energy.

[0097] After the waiting time WT elapses, the second time span ST immediately follows. In other words, the second time span ST is directly continuous with the waiting time WT. From Figure 4 As can be seen and understood, the waiting time WT and the second time span ST are very small compared to the first time span FT. For example, the waiting time WT and / or the second time span ST can be equivalent to a few percentage points of the first time span FT.

[0098] During the second time span ST, the first pair of switches (i.e., SW1 and SW4) of H-bridge 28 closes again (step S2). As a result, a certain amount of capacitive energy stored in buffer capacitor 46 is discharged by supplying said capacitive energy to motor 20 of vehicle 10 via motor interface 26 (see [link to relevant documentation]). Figure 4 (The shaded portion in the image). In other words, the amount of capacitive energy stored in the buffer capacitor 46, generated from the initial inductor energy stored in the converter unit 18, is used to power the motor 20 of the vehicle 10.

[0099] In short, disconnecting the first pair of switches (i.e., SW1 and SW4) generates an induced current for charging the buffer capacitor 46. The buffer capacitor 46 and the inductor-bearing portion of the converter unit 18 form an oscillating circuit. Therefore, the charge in the buffer capacitor 46 oscillates back. This is used to power the motor 20 during the second time span ST.

[0100] In this example, the waiting time WT and / or the second time span ST are continuously or periodically optimized based on the capacitance of the buffer capacitor 46 and the inductance of the converter unit 18 (step S3).

[0101] The optimization steps involve optimizing the latency WT and / or the second time span ST based on first data D1, which indicates the capacitive energy stored in the buffer capacitor 46. Furthermore, the optimization steps involve optimizing the latency WT and / or the second time span ST based on second data D2, which indicates the current measured at the power interface 24 after the first time span FT.

[0102] First, the optimization of the waiting time WT and / or the second time span ST based on the first data D1, which indicates the capacitive energy stored in the buffer capacitor 46, will be explained.

[0103] The amount of capacitive energy stored in the buffer capacitor 46 can be expressed by the formula The voltage across the buffer capacitor 46 is derived, where C represents the capacitance of the buffer capacitor 46 and U represents the voltage across the buffer capacitor 46.

[0104] Therefore, the voltage across the buffer capacitor 46 can be expressed as a first data D1 indicating the amount of capacitive energy stored in the buffer capacitor 46.

[0105] To obtain first data D1 (step S4) indicating the amount of capacitive energy stored in the buffer capacitor 46, the converter unit 18 includes a first sensing unit 47 electrically connected in parallel with the buffer capacitor 46. In this example, the first sensing unit 47 includes a voltmeter 48. The voltmeter 48 is communicatively connected to the data processing device 32.

[0106] exist Figure 5 The schematic diagram illustrates a representative process of the amount of capacitive energy stored in buffer capacitor 46 with the waiting time WT and the second time span.

[0107] It can be observed that the amount of capacitive energy stored in the buffer capacitor 46 increases until it reaches a maximum value of 50 during the waiting time WT. This part of the process of storing capacitive energy in the buffer capacitor 46 represents the charging of the buffer capacitor 46 through the inductance of the converter unit 18.

[0108] Starting from the maximum amount of capacitive energy and still within the waiting time WT, a decrease in the amount of capacitive energy stored in buffer capacitor 46 can be observed. This part of the process of the amount of capacitive energy stored in buffer capacitor 46 represents the discharge of buffer capacitor 46. During discharge, the capacitive energy stored in buffer capacitor 46 returns towards the inductor oscillation of converter unit 18. Additionally or alternatively, the capacitive energy stored in buffer capacitor 46 is supplied to power supply 16 via power interface 24. In other words, power supply 16 (in this example, traction battery 14) is charged by the capacitive energy stored in buffer capacitor 46.

[0109] Ideally, the amount of capacitive energy stored in the buffer capacitor 46 reaches its maximum value precisely at the end of the waiting time WT. In this way, the maximum amount of inductive energy stored in the converter unit 18 is converted into capacitive energy, which can be used to power the motor 20 of the vehicle 10 in a subsequent step of the method (i.e., during the second time span ST).

[0110] Therefore, the waiting time WT is adjusted based on the first data D1 (step S5).

[0111] If as Figure 5 As shown, the amount of capacitive energy stored in the buffer capacitor 46 decreases toward the end of the waiting time WT, thus shortening the waiting time WT.

[0112] If the amount of capacitive energy stored in the buffer capacitor 46 reaches its maximum value exactly at the end of the waiting time WT, then the waiting time WT is extended.

[0113] Based on the first data D1, not only the waiting time WT is adjusted, but also the second time span ST. The underlying concept is also... Figure 5 As shown in the image.

[0114] exist Figure 5 As can be observed in the schematic diagram, the buffer capacitor 46 rapidly releases its stored capacitive energy in an exponentially decreasing manner during the second time span ST. This means that in step S2, i.e. during the second time span ST, when the first pair of switches SW1 and SW4 of the H-bridge 28 are closed, the capacitive energy stored in the buffer capacitor 46 is provided to the motor 20 of the vehicle 10.

[0115] from Figure 5 As can be observed in the schematic diagram, approximately 75% of the capacitive energy stored in the buffer capacitor 46 at the end of the waiting time WT is discharged from the buffer capacitor 46 to the motor 20 of the vehicle 10 during the second time span ST.

[0116] The percentage of capacitive energy stored in the buffer capacitor 46 and discharged to the motor 20 of the vehicle 10 at the end of the waiting time WT is changed by adjusting the second time span ST (S5).

[0117] If, in this example, more than 75% of the capacitive energy stored in the buffer capacitor 46 will be discharged to the motor 20 of the vehicle 10 at the end of the waiting time WT, then the second time span ST needs to be extended.

[0118] If, in this example, less than about 75% of the capacitive energy stored in the buffer capacitor 46 at the end of the waiting time WT will be discharged to the motor 20 of the vehicle 10, then the second time span ST needs to be shortened.

[0119] Note that it is generally impossible to discharge all the capacitive energy stored in the buffer capacitor 46 at the end of the waiting time WT. This is because, since the capacitive energy stored in the buffer capacitor 46 decreases exponentially during discharge, this would require an excessively long time. An excessively long second time span ST will negatively and disproportionately interact with the normally expected sinusoidal voltage curve that should be supplied to the motor 20 of the vehicle 10.

[0120] Figure 6 The schematic diagram illustrates an illustrative comparison of the amount of capacitive energy stored in the buffer capacitor 46 during the first time span FT, the waiting time WT, the second time span ST, and the time period immediately following the second time span ST, when the method for controlling the converter unit 18 of the motor 20 of the vehicle 10 is executed and when the method is not executed.

[0121] The solid line represents the amount of capacitive energy stored in the buffer capacitor 46 when the method for controlling the motor 20 of the vehicle 10 is executed by the converter unit 18. It can be observed that the buffer capacitor 46 discharges rapidly during the second time span ST. This is because in step S2, i.e. during the second time span ST, when the first pair of switches SW1, SW4 of the H-bridge 28 are closed, the capacitive energy stored in the buffer capacitor 46 is supplied to the motor 20 of the vehicle 10.

[0122] The dashed line represents the amount of capacitive energy stored in the buffer capacitor 46 when the method is not executed. It can be observed that although the waiting time WT has elapsed, the buffer capacitor 46 remains charged through the inductor of the converter unit 18. Therefore, the buffer capacitor 46 absorbs more energy when the method is not executed than when it is executed. After the buffer capacitor 46 reaches its maximum charge, it slowly discharges, dissipating the capacitive energy stored in the buffer capacitor 46 as a loss into the environment, without utilizing said energy to power the motor 20 of the vehicle 10.

[0123] Therefore, the method of executing the converter unit 18 for controlling the motor 20 of the vehicle 10 reduces energy loss, improves the energy efficiency of the converter unit 18, and thus also improves the energy efficiency of powering the motor 20 of the vehicle 10. Furthermore, a buffer capacitor 46 with a relatively small capacitance can be used. In particular, the capacitance of the buffer capacitor 46 can be smaller than the capacitance in the case where the method for controlling the converter unit 18 is not executed.

[0124] The optimization of the latency WT and / or the second time span ST will be explained below, based on the second data D2, which indicates the current at the power interface 24 measured after the first time span FT.

[0125] Figure 7 A schematic diagram shows the current flowing through power interface 24 measured after the first time span FT (more precisely, during the waiting time WT). Therefore, Figure 7 The diagram shows the representation of the second data D2 after the first time span FT.

[0126] To obtain the second data D2 (step S6), the converter unit 18 includes a second sensing unit 51. In this example, the second sensing unit 51 includes a shunt 52. The shunt 52 is inserted between the connection interface of the power interface 24 and the H-bridge 28. Furthermore, the shunt 52 is communicatively connected to the data processing device 32.

[0127] exist Figure 7 During the waiting time WT shown in the schematic diagram, current flows from the converter unit 18 back to the traction battery 14. This is because the capacitive energy stored in the buffer capacitor 46 is discharged into the traction battery 14 during the waiting time WT. This situation corresponds to... Figure 5 As shown, the amount of capacitive energy stored in buffer capacitor 46 decreases before the waiting time WT ends.

[0128] Therefore, if current flowing back from converter unit 18 to traction battery 14 is detected during the waiting time WT, the waiting time WT is shortened to prevent further such current flow. In other words, the waiting time WT is adjusted based on the second data D2 (step S7).

[0129] Figure 8 The current flow across power interface 24 is shown during and after the second time span ST.

[0130] During the second time span ST, no current flow was observed across power interface 24. Immediately after the second time span ST, negative current flow was observed across power interface 24. Therefore, the current flows back into the traction battery 14 connected to power interface 24. In other words, the traction battery 14 is charged immediately after the second time span ST.

[0131] This indicates that the second time span ST ended too early, because a considerable amount of capacitive energy was still stored in the buffer capacitor 46 at the end of the second time span ST. When the first pair of switches SW1 and SW4 of the H-bridge 28 were opened after the second time span ST, the capacitive energy still stored in the buffer capacitor 46 charged the traction battery 14.

[0132] To prevent the traction battery 14 from being charged through the capacitive energy stored in the buffer capacitor 46, the second time span ST is adjusted based on the second data D2 (step S7). In the above scenario, the second time span ST is extended to reduce the amount of capacitive energy still stored in the buffer capacitor 46 at the end of the second time span ST.

[0133] Figure 9 An alternative scenario is shown for current flow across the power interface during the second time span ST.

[0134] It can be observed that, towards the end of the second time span ST, there is an increased current flowing from the traction battery 14 to the converter unit 18. This indicates that the second time span ST is too long, meaning that the first pair of switches of the H-bridge 28 has been closed again for too long, causing the buffer capacitor 46 to have significantly depleted its capacitive energy by the end of the second time span ST. Therefore, current flows from the traction battery 14 to the motor 20 of the vehicle 10.

[0135] To avoid consuming electrical energy from the traction battery 14 during the second time span ST, the second time span ST is shortened (step S7).

[0136] Note that the above method steps (steps S1 to S7) can be executed in consecutive repetitive cycles. Therefore, switches SW1, SW2, SW3, and SW4 of the H-bridge 28 can be actuated (steps S1 and S2), and the first data D1 and the second data D2 obtained during the waiting time WT and during and after the second time span ST can be obtained (steps S4 and S6). Subsequently, the waiting time WT and / or the second time span ST can be optimized (steps S5 and S7) for the next cycle execution of steps S1 and S2. In other words, the optimization (step S3) takes effect for the next cycle execution of steps S1 and S2. In this case, all or some of steps S4, S5, S6, and S7 can also be parallelized.

[0137] Alternatively, the waiting time WT and / or the second time span ST can be adjusted in real time. This means that method steps S4 to S7 can be executed in parallel with method steps S1 and S2. In other words, the optimization (step S3) takes effect in the same execution cycle as the cycle in which the first data D1 and the second data D2 are obtained (steps S4 and S6).

[0138] In the above scenario, the waiting time WT and the second time span ST have been described as adjustable and optimizable. In an alternative scenario, the waiting time WT and the second time span ST are fixed. Therefore, they are not optimized during the execution cycle of the method used to control the converter unit 18 of the motor 20 of the vehicle 10.

[0139] The fixed waiting time WT and the fixed second time span ST are based on the inductance of converter unit 18 and the capacitance of buffer capacitor 46. The concept behind this is that the inductance of converter unit 18 and the capacitance of buffer capacitor 46 form an oscillating circuit, in other words, a resonant circuit.

[0140] The duration d0 of the oscillating circuit is given by the formula Definition. A fixed predetermined waiting time WT is set to one-quarter of the time period duration d0. In this example, the buffer capacitor 46 is expected to be fully charged after one-quarter of the time period duration d0 has elapsed.

[0141] The fixed second time span ST is defined based on the capacitance of the buffer capacitor 46. The time period t during which the capacitor discharges half its capacitive charge is also defined. H Usually derived from formula t H =RC ln(2) is defined, where R represents the resistance of resistor 30 (in ohms) and C represents the capacitance of buffer capacitor 46 (in farads). A fixed second time span ST is set as the time period t. H Twice, that is, 2t H Therefore, at the end of the waiting time WT, three-quarters of the capacitive energy stored in the buffer capacitor 46 is discharged and can be used to power the motor 20 of the vehicle 10.

[0142] As a general note, the sinusoidal voltage supplied to the motor 20 of the vehicle 10 has already been discussed (see [reference]). Figure 3 The sixth step, which performs the approximation, explains method steps S1 to S7. It should be noted that method steps S1 to S7 are performed for each step of the sinusoidal voltage approximation.

[0143] also, Figure 3 The sinusoidal voltage refers only to one phase of the motor 20 of the vehicle 10. It should be understood that steps S1 to S7 are also performed for any voltage step of the other phases of the motor 20 of the vehicle 10.

[0144] As used herein, the phrase “at least one” when referring to a list of one or more entities should be understood to mean at least one entity selected from any one or more entities in the entity list, but not necessarily including at least one of each entity specifically listed in the entity list, and does not exclude any combination of entities in the entity list. This definition also allows for the optional presence of entities other than those specifically identified within the entity list referred to by the phrase “at least one,” whether related to or unrelated to those specifically identified entities. Thus, as a non-limiting example, “at least one of A and B” (or equivalently, “at least one of A or B”, or equivalently, “at least one of A and / or B”) could in one example refer to at least one (optionally including more than one) A, without B (and optionally including entities other than B); in another example, it could refer to at least one (optionally including more than one) B, without A (and optionally including entities other than A); and in yet another example, it could refer to at least one (optionally including more than one) A and at least one (optionally including more than one) B (and optionally including other entities). In other words, the phrases “at least one,” “one or more,” and “and / or” are open-ended expressions that are both connected and separate in operation. For example, each of the expressions “at least one of A, B, and C,” “at least one of A, B, or C,” “one or more of A, B, and C,” “one or more of A, B, or C,” and “A, B, and / or C” can mean a single A, a single B, a single C, A and B together, A and C together, B and C together, A, B, and C together, and optionally any of the above combined with at least one other entity.

[0145] By studying the accompanying drawings, the disclosure, and the appended claims, those skilled in the art can understand and implement other variations of the disclosed examples in practice with respect to the claimed disclosure. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite articles "a" or "an" do not exclude multiple. A single processor or other unit can perform the functions of several items or steps recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used for benefit. Computer programs can be stored / distributed on suitable media, such as optical storage media or solid-state media provided with or as part of other hardware, but can also be distributed in other forms, such as via the Internet or other wired or wireless telecommunications systems. Any reference numerals in the claims should not be construed as limiting the scope of the claims.

[0146] List of reference numerals

[0147] 10 vehicles

[0148] 12 Transmission Components

[0149] 14 Traction Battery

[0150] 16 Power Supply

[0151] 18 converter units

[0152] 20 motors

[0153] 22 Front wheels

[0154] 24 Power Interfaces

[0155] 26 Motor Interface

[0156] 28 H Bridge

[0157] 30 resistor

[0158] 32 Data processing device

[0159] 34 Data storage units

[0160] 36 Data Processing Units

[0161] 38 Computer-readable storage media

[0162] 40 Computer Programs

[0163] 42. Apparatus for performing a method for controlling a motor converter unit of a vehicle.

[0164] 44 Induced charge

[0165] 46. ​​Buffer capacitor

[0166] 47 First Sensing Unit

[0167] 48 Voltmeter

[0168] 50 The maximum amount of energy in a capacitor

[0169] 51 Second sensing unit

[0170] 52 splitter

[0171] D1 First Data

[0172] D2 Second Data

[0173] FT First Time Span

[0174] ST Second Time Span

[0175] SW1 First Switch

[0176] SW2 Second Switch

[0177] SW3 Third Switch

[0178] SW4 Fourth Switch

[0179] WT Waiting Time

Claims

1. A method for controlling a converter unit (18) of a motor (20) of a vehicle (10), the converter unit (18) comprising a power interface (24), a motor interface (26), at least one H-bridge (28), and at least one buffer capacitor (46), wherein the H-bridge (28) and the at least one buffer capacitor (46) are electrically inserted between the power interface (24) and the motor interface (26), and wherein switches (SW1, SW2, SW3, SW4) are provided on each branch of the H-bridge (28), the method comprising: - During a first predetermined time span (FT), a pair of switches (SW1, SW2, SW3, SW4) are closed to supply current (S1) to the motor interface (26), and - During the second predetermined time span (ST) and after a predetermined waiting time (WT), the pair of switches (SW1, SW2, SW3, SW4) are closed to supply induced current to the motor interface (26). The first predetermined time span (FT) and the second predetermined time span (ST) are associated with the same current supply half-cycle (S2).

2. The method according to claim 1, wherein, The second predetermined time span (ST) and the predetermined waiting time (WT) are very small compared to the first predetermined time span (FT).

3. The method according to claim 1 or 2, wherein, The second predetermined time span (ST) and / or the predetermined waiting time (WT) are fixed.

4. The method according to claim 1 or 2, wherein, The predetermined waiting time (WT) and / or the second predetermined time span (ST) are based on the inductance of the converter unit (18) and the capacitance of the at least one buffer capacitor (46).

5. The method according to claim 1 or 2, further comprising optimizing the second predetermined time span (ST) and / or the predetermined waiting time (WT) (S3).

6. The method according to claim 1 or 2, wherein, The method further includes: - Obtain first data (D1) (S4) indicating the amount of capacitive energy stored in the at least one buffer capacitor (46), and - Adjust the predetermined waiting time (WT) and / or the second predetermined time span (ST) based on the first data (D1) (S5).

7. The method according to claim 1 or 2, further comprising: - Obtain second data (D2) (S6) indicating the current at the power interface (24) measured after the first predetermined time span (FT), and - Adjust the predetermined waiting time (WT) and / or the second predetermined time span (ST) based on the second data (D2) (S7).

8. A data processing apparatus (32) comprising a component (42) for performing the method of any one of claims 1 to 7.

9. A computer program (40) comprising instructions which, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 7.

10. A computer-readable storage medium (38) including instructions that, when executed by a computer, cause the computer to perform the method according to any one of claims 1 to 7.

11. A converter unit (18) for a motor (20) of a vehicle (10), the converter unit (18) comprising: - Power interface (24) that can be connected to a power source (16). - Motor interface (26) that can be connected to the motor (20). - At least one H-bridge (28), wherein switches (SW1, SW2, SW3, SW4) are provided on each branch of the H-bridge (28). - At least one buffer capacitor (46), and - The data processing apparatus (32) according to claim 8. The H-bridge (28) and the at least one buffer capacitor (46) are electrically inserted between the power interface (24) and the motor interface (26), and the data processing device (32) is communicatively connected to the switches (SW1, SW2, SW3, SW4) of the H-bridge (28).

12. The converter unit (18) according to claim 11 further includes a first sensing unit (47) for providing first data (D1) indicating the amount of capacitive energy stored in the buffer capacitor (46).

13. The converter unit (18) according to claim 11 further includes a second sensing unit (51) for providing second data (D2) indicating the current at the power interface (24).

14. A drive assembly (12) for a vehicle (10) comprising a converter unit (18) according to any one of claims 11 to 13 and a motor (20), wherein the motor (20) is electrically coupled to the motor interface (26) of the converter unit (18).

15. A vehicle (10) comprising a drive assembly (12) according to claim 14.

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