System for controlling the operation of a vehicle with an inverter module

Abstract

A system for controlling the operation of a vehicle with an inverter module includes an alternating current (AC) power bus coupled to the inverter module. The AC power bus has multiple bus bars for conducting a multi-phase AC current. The AC power bus is coupled to a stator in an electric motor configured to generate torque to propel the vehicle. A controller is designed to determine an estimated temperature of the AC power bus for the multiple phases based on a variety of factors. These factors include the oil flow rate of any engine oil and the coolant flow rate of any inverter coolant, each of which is in direct or indirect thermal contact with the multiple bus bars.The control system is designed to regulate the operation of the vehicle partly based on the highest of the estimated temperatures of the multiple phases.

Description

[0001] The description refers generally to a system for controlling the operation of a vehicle with an inverter module. More specifically, the description refers to determining an estimated temperature for an alternating current (AC) power bus coupled to the inverter module. Hybrid and electric vehicles generally have an AC electric motor driven by a direct current (DC) source, such as a rechargeable battery. The stator windings of the electric motor may be coupled to an inverter, which converts the DC current into AC current to drive the electric motor. The electric motor powers the drive system of the hybrid and electric vehicle. The AC power bus and its associated components may experience thermal limitations under certain drive system operating conditions.However, the drive system may not have physical sensors on the AC power bus and associated components for temperature monitoring.

[0002] US 2022 / 0 196 483 A1 describes a temperature estimation device comprising: an initial value estimation unit that estimates an initial temperature value of an estimation target component at the beginning of operation of a current transformer electrically connected to an energy storage device; a variation estimation unit that estimates a temperature variation of the estimation target component based on the value of an electric current supplied by the current transformer during operation of the current transformer; and a temperature estimation unit that calculates an estimated temperature of the estimation target component based on the initial temperature value and the temperature variation.The initial estimation unit estimates the initial temperature value based on the time that has elapsed between the previous output of a temperature estimation stop instruction for the estimation target component and the current output of a temperature estimation start instruction for the estimation target component.

[0003] DE 10 2023 102 747 A1 describes a control system that reduces the power output of an inverter in an electric drive system. A detected temperature associated with the inverter, a detected current output of the inverter, and parameter values ​​of an inverter busbar indicate when a predicted busbar temperature exceeds a threshold, in order to keep the busbar temperature below that threshold. The inverter's current output can be output via the busbar. The parameter values ​​can be obtained from a thermal model of the busbar.The thermal model can be derived from testing a test version of the inverter under different drive cycles, where for each drive cycle a set of information is recorded, including a recorded temperature of the test inverter, a recorded current output of the test inverter, and a recorded temperature of the busbar of the test inverter.

[0004] DE 10 2011 075 605 A1 describes an electric motor system comprising: an electric motor having a stator with windings and a rotor configured to provide a motor speed; a cooling system comprising a coolant configured to cool the rotor and the stator, the coolant having a coolant flow rate and a coolant temperature; an inverter module coupled to the electric motor and configured to supply current to the windings based on inverter control signals; a current-controlled torque control element coupled to the inverter module and configured to generate the inverter control signals in response to a reduced torque command;and a temperature estimation control element coupled to the current-controlled torque control element and configured to generate the reduced torque command based on an initial torque command and an estimated stator winding temperature. The temperature estimation control element is configured to estimate the stator winding temperature based on the motor speed and the coolant flow rate.

[0005] According to the invention, a system for controlling the operation of a vehicle with an inverter module is described. The system comprises an alternating current (AC) power bus coupled to the inverter module. The AC power bus has a plurality of bus rails for conducting a multi-phase AC current. An electric motor is configured to generate torque to propel the vehicle. The AC power bus is coupled to a stator of the electric motor. An inverter coolant and motor oil are each in direct or indirect thermal contact with the plurality of bus rails. The system includes a controller configured to determine an estimated temperature of the AC power bus for each of the multiple phases based on a plurality of factors. The controller includes a processor and tangible, non-transient memory in which instructions are recorded.The numerous factors include the engine oil flow rate and the inverter coolant flow rate. The control system is designed to regulate vehicle operation, in part, based on the highest of the estimated temperatures across multiple phases.

[0006] According to one embodiment, the highest of the estimated temperatures of the multiple phases in a three-phase system is the estimated temperature that is highest among the three phases.

[0007] According to another embodiment, a common-mode choke is in thermal contact with the plurality of bus rails. The plurality of factors includes an estimated choke heat for the common-mode choke, wherein the estimated choke heat is based partly on a switching frequency, a modulation index, and a PWM type of the inverter module.

[0008] According to another embodiment, the estimated throttling heat, Q choke , for each of the several phases obtained as follows: Qchoke=[Qbase∗fswKfsw∗KPWM∗KMI]. Q is involved base a calibratable value for the basic heat loss is, f sw is the switching frequency, K fsw is a calibratable scalar value for the switching frequency, and K MI , K PW M These are the respective calibratable values ​​based on the modulation index and the PWM type.

[0009] According to another embodiment, controlling the operation of the vehicle includes determining an inverter capability of the inverter module based partly on the estimated temperature, and reducing the torque based partly on the inverter capability.

[0010] According to another embodiment, the vehicle includes a secondary inverter, wherein controlling the operation of the vehicle includes load distribution with the secondary inverter partly based on the inverter capability.

[0011] According to another embodiment, determining the estimated temperature of the AC power bus includes initializing it to a start temperature for each of the multiple phases. The start temperature is based partly on the shutdown temperature of the AC power bus upon vehicle shutdown, the elapsed time between vehicle shutdown and restart, a calibratable time constant for the AC power bus, and an expected cooling temperature for the AC power bus.

[0012] According to another embodiment, the starting temperature (T ACBB ) of the AC power bus received as: T ACBB = [T Clnt + (T KeyOff- T Clnt ) * e -tinactv*τ ]. Here, T KeyOff the shutdown temperature of the AC power bus when the vehicle is shut down, t inactv the elapsed time between a vehicle shutdown and a vehicle restart, τ the calibratable time constant for the AC power bus and T Clnt is the expected cooling temperature for the AC power bus.

[0013] According to another embodiment, the plurality of factors comprises the respective electrical resistances of the plurality of busbars. These respective electrical resistances are based on a calibratable nominal electrical resistance of the plurality of busbars at 25°C, Rc. 25C , the starting temperature,T ACBB , and a temperature coefficient of copper.

[0014] According to another embodiment, the multitude of factors includes a respective heat flow between the AC power bus and reference components for each of the multiple phases, wherein the respective heat flow, G ref , is received as: Q ref = [T ref - T ACBB ] * K ref . Here T denotes ref a respective temperature of the reference components, T ACBB the respective temperature of the multitude of bus tracks is designated, and K ref denotes the respective thermal conductivity of the reference components.

[0015] According to another embodiment, the reference components include the stator, the inverter module, the motor oil and inverter coolant, and a common-mode choke in thermal connection with the plurality of bus rails.

[0016] According to a further embodiment, the plurality of factors includes the respective electrical losses of the plurality of busbars, wherein the respective electrical losses, P loss , partly at a rotational speed, N Mtr , of the electric motor in RPM, and a calibratable speed threshold, N Thrs , to determine whether the electric motor is in stall mode. The respective electrical losses can be based on an RMS value of the current, I RMS , when the electric motor is in non-stop operation, and the individual phase currents, I abc , when the electric motor is in stall mode.

[0017] An example describes a method for operating a vehicle with an inverter module, an electric motor configured to generate torque, and a controller comprising a processor and tangible, non-transient memory. The method involves connecting an AC power bus to the inverter module, the AC power bus having a plurality of bus rails for carrying a multi-phase AC current. The AC power bus is coupled to a stator in the electric motor. The method includes positioning the plurality of bus rails so that each is in thermal contact with an inverter coolant and motor oil.The procedure involves determining an estimated temperature of the AC power bus for each of the multiple AC current phases based on a variety of factors, including the engine oil flow rate and the inverter coolant flow rate. Controlling the vehicle's operation can be based, in part, on the highest of the estimated temperatures for the multiple phases.

[0018] The above features and advantages, as well as other features and advantages of the present description, are readily apparent from the following detailed description of the best ways of carrying out the description in conjunction with the attached drawings. Fig. Figure 1 is a schematic representation of a system for a vehicle with an inverter, an electric motor and a control system; Fig. 2 is a flowchart for a process controlled by the control of Fig. 1 can be executed; Fig. 3 is a flowchart of part of the process of Fig. 2; Fig. 4 is a flowchart for another procedure, which is controlled by Fig. 1 can be executed; and Fig. 5 is a schematic diagram of an example architecture, which is based on the system of Fig. 1 can be used.

[0019] Referring to the drawings, in which identical reference numbers refer to identical components, shows Fig. Figure 1 schematically depicts a system 10 with an AC power bus 12. The AC power bus 12 consists of multiple busbars, such as a first busbar 14, a second busbar 16, and a third busbar 18. The AC power bus 12 can be part of a vehicle 20, which may be, among other things, a passenger car, a sport utility vehicle, a light truck, a heavy-duty vehicle, a minivan, a bus, a transit vehicle, a bicycle, a self-driving robot, agricultural equipment (for example, a tractor), sports equipment (for example, a golf cart), a boat, an aircraft, a train, or any other mobile platform. The vehicle 20 may be fully or partially electric. It is understood that the vehicle 20 can take many different forms and have additional components.

[0020] The AC power bus 12 serves as a node for receiving and transmitting electrical current and heat. Fig. Figure 1 illustrates the reception and transmission of electrical energy and heat through the AC power bus 12 using a series of bidirectional arrows. Arrows A, B, C, D, E, F (shown shaded) denote the alternating current and heat flow. Arrows G, H, I, J, K, L, M, N, P denote the heat flow.

[0021] As in Fig. As shown in Figure 1, the system 10 comprises an inverter module (PIM) 22, a rechargeable energy storage system (RESS) 24, an electric motor (EM) 26, and a gearbox 28. The inverter module 22 receives DC voltage from or to the rechargeable energy storage system 24 (for example, a high-voltage battery) and is configured to convert DC voltage into AC voltage and vice versa, for example, in response to pulse-width modulation signals. Arrows A, B, and C show the bidirectional current and heat flow between the inverter module 22 and the AC power bus 12 (the first busbar 14, the second busbar 16, and the third busbar 18, respectively).

[0022] The alternating voltage is transmitted to the stator 25 of the electric motor 26 via the AC power bus 12. The AC power bus 12 is connected to the individual phase windings of the electric motor 26. Arrows D, E, and F show the bidirectional current and heat flow between the electric motor 26 and the AC power bus 12 (the first bus 14, the second bus 16, and the third bus 18, respectively). The energized electric motor 26 delivers mechanical power or torque to an input element of the gearbox 28, with the output torque being transmitted to an output element of the gearbox 28 and finally, via one or more drive shafts (not shown), to the drive wheels 30.

[0023] The AC power bus 12 and its associated components, such as sensors, insulators, and seals, can represent a thermal limit under many operating conditions of an electric drive system. The temperature of an AC power bus 12 depends on numerous factors, including internal heat losses due to the electrical power transmitted by the AC power bus 12, its electrical resistance, and external heat transferred to or from associated or nearby components, such as cooling fluids. Due to the complexity and number of heat sources, determining the temperatures of individual components is not trivial.

[0024] System 10 enables an estimation of the temperature of an AC power bus 12 over a wide range of applications and operating profiles. Referring to Fig. 1 The system 10 comprises a controller 50 with at least one processor 52 and at least one memory 54 (or a non-transferable, tangible, computer-readable medium) in which instructions for a method 100 for operating the system 10 can be recorded, which is described below and set forth in the Fig. Figure 2-3 shows that memory 54 can store control-executable instruction sets, and processor 52 can execute the control-executable instruction sets stored in memory 54.

[0025] As in Fig. As shown in Figure 1, a common-mode choke 32 (hereinafter referred to as "choke") can be coupled to the AC power bus 12. The choke 32 is designed to filter common-mode currents and can serve as a heat source. The choke 32 is in thermal contact with each component of the AC power bus 12, as indicated by arrows G, H, and I. The controller 50 is designed to selectively implement a choke heat estimator 200, which is described below with respect to Fig. 4 is described in order to determine an estimated temperature of the throttling heat.

[0026] The AC power bus 12 also interacts with a PIM coolant 34, as indicated by arrows J, K, L, and with engine oil 36, as indicated by arrows M, N, P. Referring to Fig. 1. The vehicle 20 can include one or more secondary inverters 40 and a secondary torque source 42 (for example, an internal combustion engine). The secondary torque source 42 is configured to selectively provide a secondary torque contribution to the propulsion of the vehicle 20, for example, via the wheels 30.

[0027] By estimating the temperature of the AC power bus 12, the system enables potential derating and load distribution, for example, thermal load balancing between different inverters (e.g., the secondary inverter 40) in applications with multiple drives and / or using the secondary torque source 42. This can increase the vehicle's performance, as the load can be shifted to a drive system where the risk of power reduction is lower in order to maintain vehicle speed under high AC current conditions. In particular, this function can be used to support demanding operating profiles with high and / or sustained AC currents, such as towing, repeated acceleration with the accelerator pedal fully open, and holding the vehicle 20 on inclines using the torque of the traction motors.

[0028] In Fig. Figure 2 shows an example flowchart of procedure 100. Procedure 100 can be executed as computer-readable code or as instructions issued on the controller 50. Fig. The steps are stored in step 1 and can be partially executed from it. Procedure 100 does not have to be applied in the order specified here and can be executed dynamically. Furthermore, some steps can be omitted.

[0029] In block 110, the procedure receives 100 input data such as engine speed, oil flow rate, phase currents, and temperatures of the surrounding components. The input data includes an estimated throttle heat generated by a throttle heat estimator 200, which is described below in relation to Fig. 4 is described. For a given AC power bus design, the input data can be obtained by physical sensors, finite element analysis, numerical simulation and other methods available to a person skilled in the art.

[0030] Block 115 is configured to determine whether a fault exists in the motor current. If this is the case (Block 115 = YES), the procedure 100 transitions to Block 120, in which the estimator status is set to unusable, the phase temperature is 0°C, and the AC bus rail losses are set to zero.

[0031] If this is not the case (Block 115=NO), the procedure 100 proceeds to Block 125, where the controller 50 is configured to determine whether the reference temperatures available for the surrounding components (for example, stator 25 of the electric motor 26, inverter module 22, motor oil 36, and PIM coolant 34) are acceptable. These temperatures can be obtained from sensors or estimated by other means. If the reference temperatures are not acceptable (Block 125=NO), the procedure 100 proceeds to Block 130, where the controller 50 is configured to set a predefined degraded temperature and set the estimated status to "degraded".

[0032] If the reference temperatures are acceptable (Block 125 = YES), procedure 100 proceeds to Block 140, where control 50 is configured to update the temperatures and set the estimator status to "usable". Moving from Block 140 to Block 145, control 50 is configured to determine whether a delay timer initiated at the beginning of the cycle (when vehicle 20 starts) is greater than or equal to a calibrated delay threshold. In one example, the calibrated delay threshold is set to approximately 2 seconds.

[0033] If this is not the case (block 145=NO), procedure 100 continues with block 150, where the controller 50 is configured to initialize the AC bus temperature to a starting temperature (T ACBB ) the per phase based on the temperature of the (T KeyOff) The temperature of the AC power bus 12 during vehicle shutdown 20 can be calculated, as well as how much time (t) inactv ) between vehicle shutdown and restart, a calibratable time constant (τ) for the AC power bus 12 and the reference temperature (T Clnt ) to which the AC power bus 12 would cool down. In one example, the starting temperature (T) ACBB ) of the AC power bus 12 obtained as follows: T ACBB = [T Clnt + (T KeyOff - T Clnt ) * e -tinactv*τ ].

[0034] If this is the case (Block 145=YES), procedure 100 proceeds to Block 160, which comprises sub-blocks 161 to 167, which are in Fig. 3 are shown. As in Fig. As shown in Figure 3, the control unit 50 is configured in sub-block 161 to calculate the electrical resistances per phase of the busbar as a function of the estimated bus temperature. The temperature-scaled electrical resistance (R) elec) of the AC power bus 12 can be expressed as a function of a calibratable nominal electrical resistance at 25 C (R 25C ), the estimated temperature (T ACBB ), and the temperature coefficient of copper (KCU)(0.393%C). This calculation is performed separately for each of the three phases, since R 25C can change for each phase of the busbar: R elec = [R 25C * (1 + K CU * (T ACBB - 25))].

[0035] Continue to sub-block 162 of Fig. 3. Control 50 is configured to determine whether the motor speed is less than or equal to a threshold value. If this is the case (subblock 162 = YES), procedure 100 continues with subblock 163, where control 50 is configured to calculate the electrical busbar loss per phase as a function of the individual phase currents during stalling.

[0036] If this is not the case (sub-block 162=NOT), procedure 100 continues with sub-block 164, in which the control unit 50 is configured to calculate the electrical loss of the busbar per phase. The electrical loss (P loss ) or heat loss of the AC power bus 12 can be calculated per phase, partly based on the rotational speed (N Mtr ) of the electric motor 26 in rpm and a calibratable speed threshold (N Thrs ) which determines whether the electric motor 26 is at a standstill. If, during the blocking process, the individual phase currents (l abc ) with the corresponding electrical resistance per phase (that is, power loss of phase A = Ia*Ia*Ra and power loss of phase B = Ib*Ib*Rb). The electrical power loss (P loss ) is shared with sub-blocks 162 and 163. The electrical power loss (P loss ) can be calculated as follows: Ploss={(Iabc)2∗Relec,NMtr <NThrs(IRMS)2∗Relec,NMtr≥NThrs

[0037] Moving from subblock 164 and subblock 163 to subblock 165, the control unit 50 is configured to obtain conductivity data, including the thermal conductivity per phase between the AC power bus 12 and the engine oil 36. The thermal conductivity per phase (K Oil_ACBB The value of the engine oil (36) is a function of the oil flow rate and can be determined using a reference table, for example, K Oil_ACBB (dV) = LUT(dV), where dV is the flow rate. Continue to sub-block 166 of Fig. 3. The controller 50 can be designed to calculate the heat flow per phase between the AC power bus 12 and each reference component (for example, the stator 25 of the electric motor 26, the inverter module 22, the motor oil 36, and the PIM coolant 34) as a function of the thermal conductivity. The heat flow per phase can be represented as follows: Qref=[Tref−TACBB]∗Kref

[0038] Here, Q denotes ref and T ref the respective heat flow and temperature of the individual reference components, T ACBB is the temperature of the AC bus rails and K ref The thermal conductivity. The total heat flow per phase between the AC bus rails, self-heating, and other components is represented as the sum of the calculated heat quantities: QTotal=QLoss+Qchoke+QPIM+QStator+QOil+QCoolant

[0039] Finally, in subblock 167, the temperature of the AC power bus 12 per phase can be determined as a function of the total heat flux, the bus rail temperature at the previous time, the calibratable mCp (mass*specific heat) of the bus rail and a time step: mCp(WC)=mass∗specific heat=ΔQ(W)ΔT(C)→ΔT(C)=ΔQ(W)mCp(WC)=dTdt; TN=TN−1+Δt∗dTdt=TN−1+Δt∗ΔQmCp

[0040] Back to Fig. 2: The procedure 100 transitions from block 160 to block 170, where the controller 50 is configured to store the shutdown AC bus temperatures and other data, including the maximum estimated temperature of the three phases. The maximum estimated temperature of the three phases is set as the estimated temperature of the AC power bus 12. Subsequently, in block 180, the operation of the vehicle 20 (via system 10) is controlled based on the estimated temperature. The estimated temperature is used in the sizing and load distribution algorithms, for example, by the one described in Fig. 5 monitoring controller 340 shown and described below. Controlling the operation of the vehicle 20 includes the optimal balancing of thermal loads between different components based on the estimated temperature of the AC power bus 12 (from block 170), such as redistribution to one or more secondary inverters 40 or generating torque through a secondary torque source 42.

[0041] An example of an Architecture 300 that can be used by System 10 is in Fig. Figure 5 is shown. It is understood that other types of layouts or arrangements can also be used. The throttle heat estimator, or Module 200, receives the following parameters as input: the switching frequency, the modulation index, and the PWM type. With reference to Fig. The throttle heat estimator 200 calculates the throttle heat per phase and transfers it to a temperature estimator 310. The temperature estimator 310 also receives the phase currents, the dq-axis currents, the ambient temperatures, the oil flow rate, and the engine speed as input. Both the temperature estimator 310 and the throttle heat estimator 200 utilize measured variables as well as estimates and can be optimized for accuracy and complexity. The temperature estimator 310 can accommodate an unlimited number of external heat sources and / or sinks with individually calibratable thermal resistances.

[0042] As in Fig. As shown in Figure 1, the temperature estimator 310 generates an estimated AC bus temperature, which, along with the estimator's status, is sent to the inverter capability module 320. The inverter capability module 320 calculates the inverter capability based on the estimated AC bus temperature. The output of the inverter capability module 320 is sent to a torque reduction module 330, which is designed to reduce the motor torque based on the inverter capability and the temperature limits.

[0043] As mentioned previously, the temperature output of the temperature estimator 310 can be used by monitoring controllers that have information on the temperature limits of the AC power bus 12 to transfer the torque request from an inverter approaching its temperature limit to another that is not. With reference to Fig. 5. The output of the temperature estimator 310 can also be transmitted to a monitoring controller 340, which is designed to assess the probability of reaching the thermal limit of the system 10. Based on this, the higher-level controller 340 can reprioritize strategies to prevent a temperature-related reduction in system performance, for example by redistributing torque to other drive systems in the vehicle 20.

[0044] In Fig. Figure 4 shows an exemplary flowchart of the throttle heat estimator 200, referred to here as module 200. Module 200 can be executed as computer-readable code or as instructions that are sent to the controller 50 of Fig. The steps are stored and partially executable by this module. Module 200 does not need to be applied in the order specified here and can be executed dynamically. It is understood that some steps can be omitted.

[0045] Starting with block 202 of Fig. In block 200, control 50 is configured to determine whether system 10 contains a common-mode choke 32. If not (block 202=NO), module 200 proceeds to block 204, where control 50 is configured to set the estimated choke heat to zero. If this is the case (block 202=YES), module 200 proceeds to block 206, where control 50 is configured to retrieve input data, including PWM type, circuit, frequency, and modulation index. In block 208, control 50 is configured to determine whether the output stage is open or short-circuited.

[0046] If the output stage is open or short-circuited (Block 208 = Yes), Module 200 proceeds to Block 210, where the controller 50 is configured to set the estimated throttle heat to zero. If the output stage is not open or short-circuited (Block 212 = Yes), Module 200 proceeds to Block 212, where the controller 50 is configured to determine the AC throttle heat per phase as a function of the PWM type, switching frequency, and modulation index. In one embodiment, the estimated throttle heat (Q) can be choke ) per phase are obtained as follows: Qchoke=[Qbase∗fswKfsw∗KPWM∗KMI].

[0047] Q is involved base a calibratable value for the basic heat loss, f sw a switching frequency is, K fsw a calibratable scalar value for the switching frequency is and K MI , K PW M These are the respective calibratable values ​​based on the modulation index (MI) or the PWM. K MI , KPW M can be obtained as shown below: KMI={(1−YMIXMI∗MI)+YMI,MI <XMI1,MI≥XMI KPWM={KSVPWM,PWM Type is SVPWM1,PWM Type is not SVPWM

[0048] Here is K SVPWM a calibratable scalar determined by the PWM type. Where Y MI is the calibratable y-intercept of a piecewise linear slope, X MI is the calibratable MI threshold of the piecewise linear function and K MI a predetermined scalar value. In block 214, the estimated throttling heat is applied to the in Fig. The temperature estimator shown in 5 is transferred to 310, and the module ends at 200.

[0049] With reference to Fig. 1. The vehicle 20 can contain a mobile application 56 embedded in a smart device (for example, a smartphone) that can be plugged into the vehicle 20 or otherwise paired with it. The mobile application 56 can be used to perform various parts of the method 100 described above. The circuits and components of a mobile application (“apps”) available to a person skilled in the art can be used.

[0050] In one embodiment, the control unit 50 is of Fig. 1 is installed in the vehicle 20. In another embodiment, the controller 50 can be hosted in or based on a remote cloud computing service 60. The cloud computing service 60 can comprise one or more remote servers hosted on the internet to store, manage, and process data. The cloud computing service 60 can be managed, at least in part, by personnel at different locations.

[0051] System 10 can use a wireless network 62 for communication between its various components. The wireless network 62 can be a short-range or long-range network. It can be a communication bus, which may take the form of a serial Controller Area Network (CAN bus). Alternatively, the wireless network 62 can be a serial communication bus in the form of a local area network (LAN). This LAN can include, but is not limited to, a Controller Area Network (CAN), a Controller Area Network with Flexible Data Rate (CAN-FD), Ethernet, Bluetooth, Wi-Fi, and other data transmission methods.The wireless network 62 can be a wireless local area network (LAN), which connects multiple devices via a wireless distribution method; a metropolitan area network (MAN), which connects multiple wireless LANs; or a wide area network (WAN), which covers large areas such as neighboring cities. Other types of network technologies or communication protocols available to the professional may also be used.

[0052] In summary, system 10 enables operational control based on temperature feedback on the AC power bus 12. Excessive loads are minimized because the controller 50 is designed to reduce the power consumption of system 10 and / or distribute the load. In particular, this function can improve the towing capacity of electric vehicles.

[0053] The terms “dynamic” and “dynamic” used here describe steps or processes that are executed in real time and are characterized by the fact that the states of parameters are monitored or otherwise determined and the states of the parameters are updated regularly or periodically during the execution of a routine or between iterations of the execution of the routine.

[0054] The control unit 50 of Fig. 1 can be an integral component or a separate module that is operationally coupled with other controls of the vehicle 20. The control 50 of Fig.1. A computer-readable medium (also called a processor-readable medium) includes a non-volatile (for example, tangible) medium involved in providing data (for example, instructions) that can be read by a computer (for example, by a computer's processor). Such a medium can take many forms, including, but not limited to, non-volatile and volatile media. Non-volatile media include, for example, optical or magnetic disks and other permanent storage devices. Volatile media can include, for example, dynamic random-access memory (DRAM), which can represent main memory. Such instructions can be transmitted via one or more transmission media, including coaxial cable, copper wire, and fiber optic cable, including the wires that form a system bus coupled to a computer's processor.Some forms of computer-readable media include, for example, a floppy disk, a flexible disk, a hard disk, a magnetic tape, another magnetic medium, a CD-ROM, a DVD, another optical medium, a physical medium, a RAM, a PROM, an EPROM, a FLASH EEPROM, another memory chip, or a cartridge or other medium from which a computer can read.

[0055] Lookup tables, databases, data stores, or other data repositories described here can encompass various mechanisms for storing, accessing, and querying different types of data, including a hierarchical database, a set of files in a file storage system, an application database in a proprietary format, a relational database management system (RDBMS), and so on. Each of these data repositories can be contained within a computer device running a computer operating system such as one of those mentioned above, and can be accessed over a network in one or more of the various ways. A file system can be accessed from a computer operating system and can contain files stored in various formats.An RDBMS can use the Structured Query Language (SQL) in addition to a language for creating, storing, editing and executing stored procedures, such as the PL / SQL language mentioned above.

[0056] The flowcharts shown in the figures illustrate the architecture, functionality, and operation of possible implementations of systems, procedures, and computer program products according to various embodiments of the present description. In this respect, each block in the flowchart or block diagrams can represent a module, segment, or part of the code comprising one or more executable instructions for implementing the specified logical function(s). It should also be noted that each block in the block diagrams and / or flowchart representations, and combinations of blocks in the block diagrams and / or flowchart representations, can be implemented by special hardware-based systems that perform the specified functions or actions, or by combinations of special hardware and computer instructions.These computer program instructions can also be stored in a computer-readable medium that can instruct a controller or other programmable data processing device to operate in a particular manner, such that the instructions stored in the computer-readable medium produce a manufactured item containing instructions for implementing the function / action specified in the flowchart and / or block diagram blocks.

[0057] The numerical values ​​of parameters (for example, of quantities or conditions) in this description, including the attached claims, are to be understood as being modified by the term "approximately," regardless of whether "approximately" actually precedes the numerical value or not. "Approximately" means that the stated numerical value permits a certain degree of inaccuracy (with some approximation to the accuracy of the value; approximately or reasonably close to the value; almost). If the inaccuracy indicated by "approximately" is not otherwise understood in the art with this ordinary meaning, then "approximately," as used here, at least indicates deviations that may arise from ordinary methods of measurement and use of such parameters. Furthermore, the disclosure of ranges includes the disclosure of each value and further subdivided ranges within the entire range.Each value within a range and the endpoints of a range are hereby disclosed as separate embodiments.

Claims

[1] A system (10) for controlling the operation of a vehicle (20) having an inverter module (22), comprising: an alternating current, AC, power bus (12) coupled to the inverter module (22), the AC power bus (12) having a plurality of bus bars (14, 16, 18) for carrying a multi-phase AC current; an electric motor (26) configured to generate torque to propel the vehicle (20), wherein the AC power bus (12) is coupled to a stator (25) in the electric motor (26); an inverter coolant and engine oil (36) in direct or indirect thermal contact with the plurality of bus bars (14, 16, 18); a controller (50) configured to determine an estimated temperature of the AC power bus (12) for each of the plurality of phases based on a plurality of factors, the controller (50) having a processor (52) and a tangible, non-transitory memory (54) having instructions recorded therein; wherein the plurality of factors include an oil flow rate of the engine oil (36) and a coolant flow rate of the inverter coolant; and wherein the controller (50) is configured to control operation of the vehicle (20) based in part on the highest of the estimated temperatures of the plurality of phases. [2] System (10) according to claim 1 further comprising: a common mode choke (32) in thermal communication with the plurality of bus bars (14, 16, 18); and wherein the plurality of factors include an estimated inductor heat for the common mode inductor (32), the estimated inductor heat based in part on a switching frequency, a modulation index, and a PWM type of the inverter module (22). [3] System (10) according to claim 2: where the estimated throttle heat, Q choke , for each of the multiple phases is obtained as: Qchoke=[QBase∗fswKfsw∗KPWM∗KMI]; and where Q base is a calibratable value for the background heat loss, f sw the switching frequency is, K f sw is a calibratable scalar value for the switching frequency, and K MI , K PW M are calibratable values ​​based on the modulation index and the PWM type. [4] The system (10) of claim 1, wherein controlling operation of the vehicle (20) comprises determining an inverter capability of the inverter module (22) based in part on the estimated temperature, and derating torque based in part on the inverter capability. [5] The system (10) of claim 4, wherein the vehicle (20) includes a secondary inverter (40), wherein controlling operation of the vehicle (20) comprises load sharing with the secondary inverter (40) based in part on the inverter capability. [6] System (10) according to claim 1: wherein determining the estimated temperature of the AC power bus (12) comprises initializing to a starting temperature for each of the plurality of phases; and wherein the startup temperature is based in part on a shutdown temperature of the AC power bus (12) upon a vehicle shutdown, an elapsed time between the vehicle shutdown and a vehicle restart, a calibratable time constant for the AC power bus (12), and an expected cooldown temperature for the AC power bus (12). [7] System (10) according to claim 6: where the estimated starting temperature (T ACBB ) of the AC power bus (12) is obtained as: T ACBB = [T Clnt + (T KeyOff - T Clnt ) * e -tinactv*τ ]; and where T KeyOff the shutdown temperature of the AC power bus (12) at vehicle shutdown, t inaetv is the elapsed time between a vehicle shutdown and a vehicle restart, τ is the calibratable time constant for the AC power bus (12), and T Clnt is the expected cooling temperature for the AC power bus (12). [8] The system (10) of claim 1, wherein the plurality of factors comprise respective electrical resistances of the plurality of busbars (14, 16, 18), the respective electrical resistances being based on a respective calibratable nominal electrical resistance of the plurality of busbars (14, 16, 18) at 25 C, R 25C , the estimated temperature, T ACBB , and a temperature coefficient of copper. [9] System (10) according to claim 1: wherein the plurality of factors comprises a respective heat flow between the AC power bus (12) and reference components for each of the plurality of phases, the respective heat flow being obtained as: Q ref = [T ref - T ACBB ] * K ref ; and where T ref denotes a respective temperature of the reference components, T ACBB denotes the respective temperature of the plurality of bus bars (14, 16, 18), and K refthe respective thermal conductivity of the reference components. [10] The system (10) of claim 9, wherein the reference components include the stator (25), the inverter module (22), the engine oil (36), the inverter coolant, and a common mode choke (32) in thermal communication with the plurality of busbars (14, 16, 18).

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