Bus capacitor temperature online estimation method and device of motor controller

Abstract

The invention relates to the technical field of motor control, and discloses a bus capacitor temperature online estimation method and device of a motor controller, and the method comprises the steps: building a thermal network model, and determining a temperature collection point and a current collection point according to the thermal network model; capacitor direct current side copper bar loss, capacitor loss and capacitor IGBT side copper bar loss are calculated according to the current acquisition data, and a rotating speed-torque-voltage three-dimensional loss table is made; calculating a thermal resistance parameter and a thermal capacity parameter in the thermal network model; according to the current rotating speed, torque and voltage, capacitor direct current side copper bar loss, capacitor loss and capacitor IGBT side copper bar loss are inquired from a three-dimensional loss table; and establishing a thermal network state equation, and calculating the current capacitance temperature. Thermal resistance parameters and thermal capacitance parameters are obtained through experimental test calculation, capacitor direct current side copper bar loss, capacitor loss and capacitor IGBT side copper bar loss are obtained through off-line calculation, the precision of thermal network model parameters and loss is improved, and then the estimation precision of the capacitor temperature is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to a method and a device for online estimating the bus capacitor temperature of a motor controller. Background Art

[0002] Usually, DC bus capacitors have strict restrictions on their operating temperature. If the operating temperature of the capacitor exceeds its upper limit for a long time, it will cause the capacitor to fail due to overheating. Electric vehicles have long-term high-speed operation, long-term climbing and other vehicle operating conditions. If the capacitor temperature is not monitored, it is very likely to cause the capacitor to fail due to overheating.

[0003] The operating temperature range of the capacitor is narrow: the over-temperature of the capacitor is generally 105 degrees, while the cooling water temperature of the controller may be as high as 65 degrees. At this time, the operating temperature range of the capacitor is only 40 degrees. If the accuracy of the capacitor temperature estimation is not high, it is easy to limit the output capacity of the controller or cause the capacitor to overheat. Therefore, the accuracy requirement of the capacitor temperature estimation is relatively high.

[0004] However, currently, when estimating capacitor temperature, the loss is mostly estimated online by software, which can easily lead to estimation deviations, thereby reducing the accuracy of capacitor temperature estimation. Summary of the invention

[0005] In view of this, the present invention provides a method and device for online estimating bus capacitor temperature of a motor controller to solve the current problem of low capacitor temperature estimation accuracy.

[0006] In a first aspect, the present invention provides a method for online estimating bus capacitance temperature of a motor controller, the method comprising: Establishing a thermal network model, and determining temperature collection points and current collection points according to the thermal network model; Acquire current acquisition data at multiple DC voltage points, fixed step speeds and torques, calculate the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor according to the current acquisition data, and create a three-dimensional loss table of speed-torque-voltage; Through the temperature rise test, the thermal resistance parameters and thermal capacity parameters in the thermal network model are calculated in combination with the temperature acquisition data; According to the current speed, torque and voltage, query the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor from the three-dimensional loss table; A thermal network state equation is established, and the current temperature acquisition data, the thermal resistance parameter, the thermal capacitance parameter, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried from the three-dimensional loss table are substituted into the thermal network state equation to calculate the current capacitor temperature.

[0007] The present invention provides a method for online estimation of busbar capacitor temperature of a motor controller, obtains thermal resistance parameters and thermal capacitance parameters through experimental test calculation, obtains copper bar loss on the DC side of the capacitor, capacitor loss and copper bar loss on the IGBT side of the capacitor through offline calculation, improves the accuracy of thermal network model parameters and losses, and further improves the estimation accuracy of capacitor temperature. At the same time, the loss data is obtained by three-dimensional table lookup of torque, speed and voltage, avoiding the complexity of online loss estimation by software, while also improving the accuracy of loss, and further improving the estimation accuracy of capacitor temperature.

[0008] In an optional implementation, the establishing of the thermal network model and determining the temperature collection point and the current collection point according to the thermal network model include: The controller housing temperature estimation model is established using IGBT temperature, ambient temperature, cooling water temperature, thermal resistance parameters, and thermal capacitance parameters; Taking the controller shell temperature as the reference temperature, a capacitor temperature estimation model based on the controller shell temperature is established by using the copper bar loss on the DC side of the capacitor, the copper bar loss on the IGBT side of the capacitor, the capacitor loss, the copper bar temperature on the DC side of the capacitor, the copper bar temperature on the IGBT side of the capacitor, the capacitor temperature, the capacitor shell temperature, the thermal resistance parameter and the thermal capacitance parameter. The temperature collection point is determined according to the temperature parameters required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature, and the current collection point is determined according to the capacitor DC side copper bus loss, capacitor loss and capacitor IGBT side copper bus loss required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature.

[0009] The IGBT temperature, ambient temperature and cooling water temperature are used as reference temperatures to estimate the capacitor temperature. Without changing the existing structure and hardware circuit, the online estimation of the capacitor temperature is completely realized through software without increasing the product cost. At the same time, the thermal network model is split into two independent thermal network sub-models, which simplifies the thermal model and facilitates the design and implementation of the software algorithm.

[0010] In an optional implementation, the current acquisition data at multiple DC voltage points, fixed step speed and torque are acquired, the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor are calculated according to the current acquisition data, and a three-dimensional loss table of speed-torque-voltage is prepared, including: Obtain the capacitor current, busbar side copper busbar current and IGBT side copper busbar current at different DC voltage points, fixed step speed and torque; Based on the capacitor current, calculating the capacitor loss according to a loss calculation formula; Based on the busbar side copper busbar current, the capacitor DC side copper busbar loss is calculated according to the loss calculation formula; Based on the IGBT-side copper busbar current, the capacitor IGBT-side copper busbar loss is calculated according to a loss calculation formula; A three-dimensional loss table of speed-torque-voltage is made based on capacitor current, busbar side copper bus current, IGBT side copper bus current, capacitor loss, capacitor DC side copper bus loss and capacitor IGBT side copper bus loss at different DC voltage points, fixed step speeds and torques.

[0011] In an optional implementation, the thermal resistance parameter and the thermal capacity parameter in the thermal network model are calculated by combining the temperature acquisition data with the temperature rise test, including: Select different working conditions to carry out capacitor temperature rise test experiments, obtain the steady-state temperature rise data between each temperature node, and obtain the thermal resistance parameters; Different working conditions are selected to carry out capacitor temperature rise test experiments, and the transient temperature rise data between each temperature node are obtained. The thermal capacitance parameters are obtained by fitting.

[0012] In an optional implementation, a thermal network state equation is established according to the controller housing temperature estimation model and a capacitor temperature estimation model based on the controller housing temperature.

[0013] In an optional implementation, the thermal network state equation is as follows:

[0014] in, , , , , , , , , , , , , , , , , , , , , , R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R7 , R 8 , R 9 is the thermal resistance, C 1 , C 2 , C 3 , C 4 , C 5 is the heat capacity, is the copper bar temperature on the DC side of the capacitor, is the capacitor temperature, is the copper busbar temperature on the capacitor IGBT side, is the capacitor case temperature, is the controller housing temperature, is the copper busbar loss on the DC side of the capacitor, is the capacitance loss, is the copper bus loss on the capacitor IGBT side, is the IGBT temperature, is the cooling water temperature, is the ambient temperature.

[0015] In an optional implementation, the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor are queried from the three-dimensional loss table by linear interpolation.

[0016] In a second aspect, the present invention provides a bus capacitor temperature online estimation device for a motor controller, the device comprising: A model building module, used to build a thermal network model and determine the temperature collection points and the current collection points according to the thermal network model; A table making module is used to obtain current acquisition data at multiple DC voltage points, fixed step speed and torque, calculate the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor according to the current acquisition data, and make a three-dimensional loss table of speed-torque-voltage; A temperature rise test module is used to calculate the thermal resistance parameters and thermal capacity parameters in the thermal network model through a temperature rise test in combination with the temperature acquisition data; A loss query module, used to query the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor from the three-dimensional loss table according to the current speed, torque and voltage; The temperature calculation module is used to establish a thermal network state equation, substitute the current temperature acquisition data, the thermal resistance parameter, the thermal capacitance parameter, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried from the three-dimensional loss table into the thermal network state equation, and calculate the current capacitor temperature.

[0017] The present invention provides an online estimation device for the busbar capacitor temperature of a motor controller, which obtains thermal resistance parameters and thermal capacitance parameters through experimental test calculations, and obtains the copper bar loss on the DC side of the capacitor, the capacitor loss, and the copper bar loss on the IGBT side of the capacitor through offline calculations, thereby improving the accuracy of the thermal network model parameters and losses, and thus improving the estimation accuracy of the capacitor temperature. At the same time, the loss data is obtained by a three-dimensional table lookup of torque, speed, and voltage, which avoids the complexity of online loss estimation by software, and also improves the accuracy of loss, and further improves the estimation accuracy of the capacitor temperature.

[0018] In a third aspect, the present invention provides a computer device, comprising: a memory and a processor, the memory and the processor being communicatively connected to each other, the memory storing computer instructions, and the processor executing the computer instructions to execute the online estimation method for the bus capacitor temperature of the motor controller of the first aspect or any corresponding embodiment thereof.

[0019] In a fourth aspect, the present invention provides a computer-readable storage medium having computer instructions stored thereon, the computer instructions being used to enable a computer to execute the method for online estimation of the bus capacitor temperature of a motor controller of the first aspect or any corresponding embodiment thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0021] Figure 1 is a flow chart of a method for online estimating bus capacitor temperature of a motor controller according to an embodiment of the present invention; Figure 2 is a controller housing temperature estimation model according to an embodiment of the present invention; Figure 3 is a capacitor temperature estimation model based on the controller housing temperature according to an embodiment of the present invention; Figure 4 is a structural block diagram of a bus capacitor temperature online estimation device of a motor controller according to an embodiment of the present invention; Figure 5 It is a schematic diagram of the hardware structure of a computer device according to an embodiment of the present invention. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present invention.

[0023] The present invention provides an online estimation method for busbar capacitor temperature of a motor controller, which obtains thermal network and loss through experimental testing and offline calculation to improve the estimation accuracy of capacitor temperature.

[0024] According to an embodiment of the present invention, an embodiment of a method for online estimation of the bus capacitance temperature of a motor controller is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer executable instructions, and although a logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in an order different from that shown here.

[0025] In this embodiment, a method for online estimating bus capacitance temperature of a motor controller is provided. Figure 1 is a flow chart of a method for online estimating bus capacitor temperature of a motor controller according to an embodiment of the present invention. Figure 1 As shown, the process includes the following steps: Step S11, establishing a thermal network model, and determining temperature collection points and current collection points according to the thermal network model.

[0026] Specifically, a thermal network model is established based on the lumped parameter thermal network method. The thermal network model selects three main heat loss points of the motor controller film capacitor: DC capacitor DC side copper bus loss, capacitor loss, and capacitor IGBT side copper bus loss, while taking into account the impact of IGBT loss on capacitor temperature. Considering that capacitor loss and copper bus loss are much smaller than IGBT loss, the impact on the controller housing temperature rise can be ignored, so the thermal network model is simplified into two independent thermal network sub-models, namely Figure 2 Thermal network submodel and Figure 3 Thermal network sub-model, thereby reducing the complexity of the thermal network model.

[0027] Further, according to Figure 2 and Figure 3These two independent thermal network sub-models embed temperature sensors and current sensors in the motor controller and capacitor to observe and record temperature acquisition data and current acquisition data.

[0028] Step S12, obtaining current acquisition data at multiple DC voltage points, fixed step speed and torque, calculating the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor based on the current acquisition data, and making a three-dimensional loss table of speed-torque-voltage.

[0029] Specifically, the current acquisition data at multiple DC voltage points, fixed step speed and torque are obtained, the loss is calculated offline, and a three-dimensional loss table of speed-torque-voltage is made. Since the copper bar loss on the DC side of the capacitor, the capacitor loss and the copper bar loss on the IGBT side of the capacitor are obtained through offline calculation, the accuracy of the loss is improved, thereby improving the estimation accuracy of the capacitor temperature.

[0030] Step S13, calculating the thermal resistance parameters and thermal capacity parameters in the thermal network model through the temperature rise test in combination with the temperature collection data.

[0031] Specifically, for Figure 2 and Figure 3 The thermal resistance and thermal capacitance parameters in the thermal network sub-model are calculated. The thermal resistance parameters (R1~R9) are calculated through steady-state temperature rise experiments. The thermal capacitance parameters (C1~C5) are calculated by fitting using transient temperature rise data between thermal nodes. Since the thermal resistance and thermal capacitance parameters are obtained through experimental tests, the accuracy of the thermal resistance and thermal capacitance parameters is improved, thereby improving the estimation accuracy of the capacitor temperature.

[0032] Step S14, querying the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor from a three-dimensional loss table according to the current speed, torque and voltage.

[0033] Specifically, according to the current speed, torque and voltage, the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor are queried from the three-dimensional loss table by linear interpolation. The loss data is obtained by looking up the three-dimensional table of torque, speed and voltage, which avoids the complexity of online loss estimation by the software, and also improves the accuracy of loss, thereby improving the estimation accuracy of capacitor temperature.

[0034] Step S15, establish a thermal network state equation, substitute the current temperature acquisition data, thermal resistance parameters, thermal capacitance parameters, and the capacitor DC side copper bus loss, capacitor loss, and capacitor IGBT side copper bus loss queried from the three-dimensional loss table into the thermal network state equation, and calculate the current capacitor temperature.

[0035] Specifically, according to Figure 2 and Figure 3The thermal network sub-model is used to establish the thermal network state equation. The current temperature acquisition data is obtained, and the current temperature acquisition data, the thermal capacitance parameter and the thermal resistance parameter obtained in step S13, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried in step S14 are substituted into the thermal network state equation to calculate the capacitor temperature online in real time.

[0036] The present invention provides a method for online estimation of busbar capacitor temperature of a motor controller, obtains thermal resistance parameters and thermal capacitance parameters through experimental test calculation, obtains copper bar loss on the DC side of the capacitor, capacitor loss and copper bar loss on the IGBT side of the capacitor through offline calculation, improves the accuracy of thermal network model parameters and losses, and further improves the estimation accuracy of capacitor temperature. At the same time, the loss data is obtained by three-dimensional table lookup of torque, speed and voltage, avoiding the complexity of online loss estimation by software, while also improving the accuracy of loss, and further improving the estimation accuracy of capacitor temperature.

[0037] In an optional implementation, step S11 includes the following steps: Step S111 , establishing a controller housing temperature estimation model using IGBT temperature, ambient temperature, cooling water temperature, thermal resistance parameters, and thermal capacitance parameters.

[0038] Specifically, since the capacitor loss and copper busbar loss are much smaller than the IGBT loss, the capacitor loss and copper busbar loss can be ignored when establishing the controller case temperature estimation model, and only the IGBT temperature, ambient temperature, and cooling water temperature are used to estimate the controller case temperature. Figure 2 As shown, R 7 , R 8 , R 9 is the thermal resistance, C 5 is the heat capacity, is the IGBT temperature, is the cooling water temperature, is the ambient temperature.

[0039] Step S112, taking the controller housing temperature as the reference temperature, and utilizing the copper bar loss on the DC side of the capacitor, the copper bar loss on the IGBT side of the capacitor, the capacitor loss, the copper bar temperature on the DC side of the capacitor, the copper bar temperature on the IGBT side of the capacitor, the capacitor temperature, the capacitor housing temperature, the thermal resistance parameter, and the thermal capacitance parameter to establish a capacitor temperature estimation model based on the controller housing temperature.

[0040] Specifically, the controller housing temperature, capacitor DC side copper bar loss, capacitor IGBT side copper bar loss, capacitor loss, capacitor DC side copper bar temperature, capacitor IGBT side copper bar temperature, capacitor temperature, capacitor housing temperature, thermal resistance parameters and thermal capacitance parameters are used to establish the following: Figure 3 The capacitor temperature estimation model based on the controller case temperature is shown. Figure 2 The controller case temperature estimation model shown and Figure 3 The capacitor temperature estimation model based on the controller case temperature is coupled to a thermal network model through the controller case temperature. R 1 , R 2 , R 3 , R 4 , R 5 , R 6 is the thermal resistance, C 1 , C 2 , C 3 , C 4 is the heat capacity, is the copper bar temperature on the DC side of the capacitor, is the capacitor temperature, is the copper busbar temperature on the capacitor IGBT side, is the capacitor case temperature, is the controller housing temperature, is the copper busbar loss on the DC side of the capacitor, is the capacitance loss, is the copper bus loss on the capacitor IGBT side.

[0041] Step S113, determining the temperature collection point according to the temperature parameters required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature, and determining the current collection point according to the capacitor DC side copper bus loss, capacitor loss and capacitor IGBT side copper bus loss required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature.

[0042] Specifically, the temperature parameters required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature include the capacitor DC side copper bar temperature, the capacitor IGBT side copper bar temperature, the capacitor housing temperature, the controller housing temperature, the IGBT temperature, the cooling water temperature and the ambient temperature. Among them, the temperature sensors are respectively arranged on the capacitor DC side copper bar, the capacitor IGBT side copper bar, the capacitor housing, and the controller housing, and are used to measure the DC side copper bar temperature, the capacitor IGBT side copper bar temperature, the capacitor housing temperature, and the controller housing temperature, respectively. In addition, the cooling water temperature and ambient temperature of the laboratory test are controlled by a constant temperature water tank and a constant temperature environment box, the cooling water temperature and ambient temperature on the whole vehicle are obtained from the whole vehicle CAN signal, and the IGBT temperature is collected and obtained by the NTC temperature sensor built into the IGBT module.

[0043] By taking into account the impact of IGBT loss on capacitor temperature, the thermal network model is improved, making the thermal network model design more accurate and improving the accuracy of capacitor temperature estimation. The IGBT temperature, ambient temperature and cooling water temperature are used as reference temperatures to estimate the capacitor temperature. Without changing the existing structure and hardware circuit, the online estimation of capacitor temperature is completely realized through software without increasing product cost. At the same time, the thermal network model is split into two independent thermal network sub-models, which simplifies the thermal model and facilitates the design and implementation of software algorithms.

[0044] In an optional implementation, step S12 includes the following steps: Step S121, obtaining capacitor current, busbar side copper busbar current and IGBT side copper busbar current at different DC voltage points, fixed step speed and torque.

[0045] Step S122, based on the capacitor current, the capacitor loss is calculated according to the loss calculation formula.

[0046] Step S123, based on the busbar side copper bus current, calculate the capacitor DC side copper bus loss according to the loss calculation formula.

[0047] Step S124, based on the IGBT-side copper busbar current, calculate the IGBT-side copper busbar loss of the capacitor according to a loss calculation formula.

[0048] Step S125, making a three-dimensional loss table of speed-torque-voltage based on capacitor current, busbar side copper bus current, IGBT side copper bus current, capacitor loss, capacitor DC side copper bus loss and capacitor IGBT side copper bus loss at different DC voltage points, fixed step speeds and torques.

[0049] Specifically, current sensors are used to measure capacitor current, busbar copper bus current and IGBT copper bus current under different DC voltages, speeds and torques. The copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor are calculated offline, and a three-dimensional loss table of speed-torque-voltage is made.

[0050] In an optional implementation, step S13 includes the following steps: Step S131, selecting different working conditions to perform capacitor temperature rise test experiments, obtaining steady-state temperature rise data between temperature nodes, and obtaining thermal resistance parameters.

[0051] Step S132, selecting different working conditions to perform capacitor temperature rise test experiments, obtaining transient temperature rise data between temperature nodes, and obtaining thermal capacitance parameters by fitting.

[0052] Specifically, by selecting different working conditions to test the temperature rise of the capacitor, the steady-state temperature rise data between each temperature node can be obtained, and the thermal resistance parameters R1~R9 can be obtained. By selecting different working conditions to test the temperature rise of the capacitor, the transient temperature rise data between each temperature node can be obtained, and the thermal capacitance parameters C1~C5 can be obtained by fitting.

[0053] In an optional embodiment, according to Figure 2 The controller case temperature estimation model shown and Figure 3 The capacitor temperature estimation model based on the controller housing temperature is used to establish the thermal network state equation. The thermal network state equation is as follows:

[0054] in, , , , , , , , , , , , , , , , , , , , , , R 1 , R 2 , R 3 , R 4 , R 5 , R6 , R 7 , R 8 , R 9 is the thermal resistance, C 1 , C 2 , C 3 , C 4 , C 5 is the heat capacity, is the copper bar temperature on the DC side of the capacitor, is the capacitor temperature, is the copper busbar temperature on the capacitor IGBT side, is the capacitor case temperature, is the controller housing temperature, is the copper busbar loss on the DC side of the capacitor, is the capacitance loss, is the copper bus loss on the capacitor IGBT side, is the IGBT temperature, is the cooling water temperature, is the ambient temperature.

[0055] In this embodiment, a bus capacitor temperature online estimation device for a motor controller is also provided, which is used to implement the above-mentioned embodiments and preferred implementation modes, and will not be repeated hereafter. As used below, the term "module" may be a combination of software and / or hardware that implements a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, the implementation in hardware, or a combination of software and hardware, is also possible and conceivable.

[0056] This embodiment provides a busbar capacitor temperature online estimation device for a motor controller, such as Figure 4 As shown, including: The model building module 41 is used to build a thermal network model and determine the temperature collection points and the current collection points according to the thermal network model.

[0057] The table making module 42 is used to obtain current acquisition data at multiple DC voltage points, fixed step speed and torque, calculate the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor based on the current acquisition data, and make a three-dimensional loss table of speed-torque-voltage.

[0058] The temperature rise test module 43 is used to calculate the thermal resistance parameters and thermal capacity parameters in the thermal network model through the temperature rise test in combination with the temperature collection data.

[0059] The loss query module 44 is used to query the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor from the three-dimensional loss table according to the current speed, torque and voltage.

[0060] The temperature calculation module 45 is used to establish a thermal network state equation, substitute the current temperature acquisition data, thermal resistance parameters, thermal capacitance parameters, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried from the three-dimensional loss table into the thermal network state equation, and calculate the current capacitor temperature.

[0061] The further functional description of each of the above modules and units is the same as that of the above corresponding embodiments and will not be repeated here.

[0062] The bus capacitor temperature online estimation device of the motor controller in this embodiment is presented in the form of a functional unit, where the unit refers to an ASIC (Application Specific Integrated Circuit) circuit, a processor and memory that executes one or more software or fixed programs, and / or other devices that can provide the above functions.

[0063] The present invention provides an online estimation device for the busbar capacitor temperature of a motor controller, which obtains thermal resistance parameters and thermal capacitance parameters through experimental test calculations, and obtains the copper bar loss on the DC side of the capacitor, the capacitor loss, and the copper bar loss on the IGBT side of the capacitor through offline calculations, thereby improving the accuracy of the thermal network model parameters and losses, and thus improving the estimation accuracy of the capacitor temperature. At the same time, the loss data is obtained by a three-dimensional table lookup of torque, speed, and voltage, which avoids the complexity of online loss estimation by software, and also improves the accuracy of loss, and further improves the estimation accuracy of the capacitor temperature.

[0064] The embodiment of the present invention also provides a computer device having the above Figure 4 The bus capacitor temperature online estimation device of the motor controller is shown.

[0065] See also Figure 5 , Figure 5 is a schematic diagram of the structure of a computer device provided by an optional embodiment of the present invention, such as Figure 5As shown, the computer device includes: one or more processors 10, a memory 20, and interfaces for connecting various components, including high-speed interfaces and low-speed interfaces. Various components are connected to each other using different buses for communication, and can be installed on a common mainboard or installed in other ways as needed. The processor can process the instructions executed in the computer device, including instructions stored in or on the memory to display the graphical information of the GUI on an external input / output device (such as, a display device coupled to the interface). In some optional embodiments, if necessary, multiple processors and / or multiple buses can be used together with multiple memories and multiple memories. Similarly, multiple computer devices can be connected, and each device provides some necessary operations (for example, as a server array, a group of blade servers, or a multi-processor system). Figure 5 A processor 10 is taken as an example.

[0066] The processor 10 may be a central processing unit, a network processor or a combination thereof. The processor 10 may further include a hardware chip. The hardware chip may be a dedicated integrated circuit, a programmable logic device or a combination thereof. The programmable logic device may be a complex programmable logic device, a field programmable gate array, a general purpose array logic or any combination thereof.

[0067] The memory 20 stores instructions executable by at least one processor 10, so that the at least one processor 10 executes the method shown in the above embodiment.

[0068] The memory 20 may include a program storage area and a data storage area, wherein the program storage area may store an operating system, an application required for at least one function; the data storage area may store data created according to the use of the computer device, etc. In addition, the memory 20 may include a high-speed random access memory, and may also include a non-transient memory, such as at least one disk storage device, a flash memory device, or other non-transient solid-state storage device. In some optional embodiments, the memory 20 may optionally include a memory remotely arranged relative to the processor 10, and these remote memories may be connected to the computer device via a network. Examples of the above-mentioned network include, but are not limited to, the Internet, an intranet, a local area network, a mobile communication network, and combinations thereof.

[0069] The memory 20 may include a volatile memory, such as a random access memory; the memory may also include a non-volatile memory, such as a flash memory, a hard disk or a solid state drive; the memory 20 may also include a combination of the above types of memory.

[0070] The computer device further comprises a communication interface 30 for the computer device to communicate with other devices or a communication network.

[0071] The embodiment of the present invention also provides a computer-readable storage medium. The method according to the embodiment of the present invention can be implemented in hardware, firmware, or can be implemented as a computer code that can be recorded in a storage medium, or can be implemented as a computer code that is originally stored in a remote storage medium or a non-temporary machine-readable storage medium and will be stored in a local storage medium through a network download, so that the method described herein can be stored in such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only storage memory, a random access memory, a flash memory, a hard disk or a solid-state hard disk, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code. When the software or computer code is accessed and executed by a computer, a processor, or hardware, the method shown in the above embodiment is implemented.

[0072] Although the embodiments of the present invention have been described in conjunction with the accompanying drawings, those skilled in the art may make various modifications and variations without departing from the spirit and scope of the present invention, and such modifications and variations are all within the scope defined by the appended claims.

Claims

1. A method for online estimation of bus capacitance temperature of a motor controller, characterized in that: The method comprises: Establishing a thermal network model, and determining temperature collection points and current collection points according to the thermal network model; Acquire current acquisition data at multiple DC voltage points, fixed step speeds and torques, calculate the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor according to the current acquisition data, and create a three-dimensional loss table of speed-torque-voltage; Through the temperature rise test, the thermal resistance parameters and thermal capacity parameters in the thermal network model are calculated in combination with the temperature acquisition data; According to the current speed, torque and voltage, query the copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor from the three-dimensional loss table; A thermal network state equation is established, and the current temperature acquisition data, the thermal resistance parameter, the thermal capacitance parameter, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried from the three-dimensional loss table are substituted into the thermal network state equation to calculate the current capacitor temperature.

2. The method for online estimation of bus capacitance temperature of a motor controller according to claim 1, characterized in that: The step of establishing a thermal network model and determining a temperature collection point and a current collection point according to the thermal network model includes: The controller housing temperature estimation model is established using IGBT temperature, ambient temperature, cooling water temperature, thermal resistance parameters, and thermal capacitance parameters; Taking the controller shell temperature as the reference temperature, a capacitor temperature estimation model based on the controller shell temperature is established by using the copper bar loss on the DC side of the capacitor, the copper bar loss on the IGBT side of the capacitor, the capacitor loss, the copper bar temperature on the DC side of the capacitor, the copper bar temperature on the IGBT side of the capacitor, the capacitor temperature, the capacitor shell temperature, the thermal resistance parameter and the thermal capacitance parameter. The temperature collection point is determined according to the temperature parameters required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature, and the current collection point is determined according to the capacitor DC side copper bus loss, capacitor loss and capacitor IGBT side copper bus loss required by the controller housing temperature estimation model and the capacitor temperature estimation model based on the controller housing temperature.

3. The method for online estimation of bus capacitance temperature of a motor controller according to claim 1, characterized in that: The method comprises obtaining current acquisition data at multiple DC voltage points, fixed step speed and torque, calculating the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor according to the current acquisition data, and making a three-dimensional loss table of speed-torque-voltage, including: Obtain the capacitor current, busbar side copper busbar current and IGBT side copper busbar current at different DC voltage points, fixed step speed and torque; Based on the capacitor current, calculating the capacitor loss according to a loss calculation formula; Based on the busbar side copper busbar current, the capacitor DC side copper busbar loss is calculated according to the loss calculation formula; Based on the IGBT-side copper busbar current, the capacitor IGBT-side copper busbar loss is calculated according to a loss calculation formula; A three-dimensional loss table of speed-torque-voltage is made based on capacitor current, busbar side copper bus current, IGBT side copper bus current, capacitor loss, capacitor DC side copper bus loss and capacitor IGBT side copper bus loss at different DC voltage points, fixed step speeds and torques.

4. The method for online estimation of bus capacitance temperature of a motor controller according to claim 1, characterized in that: The thermal resistance parameters and thermal capacity parameters in the thermal network model are calculated by combining the temperature collection data through the temperature rise test, including: Select different working conditions to carry out capacitor temperature rise test experiments, obtain the steady-state temperature rise data between each temperature node, and obtain the thermal resistance parameters; Different working conditions are selected to carry out capacitor temperature rise test experiments, and the transient temperature rise data between each temperature node are obtained. The thermal capacitance parameters are obtained by fitting.

5. The method for online estimation of bus capacitance temperature of a motor controller according to claim 2, characterized in that: A thermal network state equation is established according to the controller housing temperature estimation model and a capacitor temperature estimation model based on the controller housing temperature.

6. The method for online estimation of bus capacitance temperature of a motor controller according to claim 5, characterized in that: The thermal network state equation is as follows: in, , , , , , , , , , , , , , , , , , , , , , R 1. R 2. R 3. R 4. R 5. R 6. R 7. R 8. R 9 is thermal resistance, C 1. C 2. C 3. C 4. C 5 is the heat capacity, is the copper bar temperature on the DC side of the capacitor, is the capacitor temperature, is the copper busbar temperature on the capacitor IGBT side, is the capacitor case temperature, is the controller housing temperature, is the copper busbar loss on the DC side of the capacitor, is the capacitance loss, is the copper bus loss on the capacitor IGBT side, is the IGBT temperature, is the cooling water temperature, is the ambient temperature.

7. The method for online estimation of bus capacitance temperature of a motor controller according to claim 1, characterized in that: The copper busbar loss on the DC side of the capacitor, the capacitor loss and the copper busbar loss on the IGBT side of the capacitor are queried from the three-dimensional loss table by linear interpolation.

8. An online estimation device for bus capacitance temperature of a motor controller, characterized in that: The device comprises: A model building module, used to build a thermal network model and determine the temperature collection points and the current collection points according to the thermal network model; A table making module is used to obtain current acquisition data at multiple DC voltage points, fixed step speed and torque, calculate the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor according to the current acquisition data, and make a three-dimensional loss table of speed-torque-voltage; A temperature rise test module is used to calculate the thermal resistance parameters and thermal capacity parameters in the thermal network model through a temperature rise test in combination with the temperature acquisition data; A loss query module, used to query the copper bus loss on the DC side of the capacitor, the capacitor loss and the copper bus loss on the IGBT side of the capacitor from the three-dimensional loss table according to the current speed, torque and voltage; The temperature calculation module is used to establish a thermal network state equation, substitute the current temperature acquisition data, the thermal resistance parameter, the thermal capacitance parameter, and the copper busbar loss on the DC side of the capacitor, the capacitor loss, and the copper busbar loss on the IGBT side of the capacitor queried from the three-dimensional loss table into the thermal network state equation, and calculate the current capacitor temperature.

9. A computer device, characterized in that: include: A memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the bus capacitor temperature online estimation method of the motor controller according to any one of claims 1 to 7 by executing the computer instructions.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores computer instructions, and the computer instructions are used to enable a computer to execute the bus capacitor temperature online estimation method of a motor controller according to any one of claims 1 to 7.

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