All-in-one power system and temperature estimation method thereof

Abstract

The present invention relates to an all-in-one power system comprising at least two power units, wherein cooling fluid of a shared cooling circuit flows sequentially through the power units. A temperature sensor is provided at a node of a thermal resistance network associated with a first power unit. A controller is configured to calculate the electrical value of the power unit by performing the following steps: a) obtaining a first cooling fluid temperature associated with the first power unit as a current starting reference temperature, setting the first power unit as the current power unit, and setting a second power unit adjacent to the current power unit in the cooling fluid flow path as the adjacent power unit; b) calculating the cooling fluid temperature associated with the adjacent power unit as an intermediate reference temperature based on the current starting reference temperature and the electrical values ​​of the current power unit and an upstream power unit; and c) estimating the temperature of each node of the thermal resistance network of the adjacent power unit based on the intermediate reference temperature and the electrical value of the adjacent power unit. The present invention relates to non-transitory computer-readable media.

Description

Technical Field

[0001] The present invention relates to an all-in-one power system for a hybrid vehicle or a battery electric vehicle and a temperature estimation method thereof. Background Art

[0002] A hybrid electric vehicle or battery electric vehicle typically includes an alternating current (AC) electric motor driven by a direct current (DC) power source, such as a battery. The stator windings of the electric motor may be coupled to a power inverter module.

[0003] A power inverter module (PIM) includes semiconductor switches, such as insulated-gate bipolar transistors (IGBTs), which are typically controlled using pulse-width modulation (PWM) techniques. The PIM's operation ultimately converts the boosted DC battery output voltage into an alternating current (AC) output voltage. The AC output voltage is then applied to the individual phase windings of the electric motor. The powered electric motor generates motor torque, which, depending on the operating mode, either powers the vehicle or recharges the battery pack. The semiconductor switches within the PIM can heat up during extended PWM switching operation.

[0004] Temperature control is particularly important for powertrains that include temperature-sensitive power components such as inverters, motors, and batteries. The junction temperature of the inverter's IGBTs can severely limit their output capacity, pose a risk of high-temperature demagnetization of permanent magnets in motors, and battery cell temperatures can cause fires. Therefore, existing powertrains incorporate cooling systems for these power components, each equipped with its own temperature sensor. For example, some temperature sensors are located on internal PCBs or other critical locations. However, the most dangerous locations, such as the inverter's IGBT housing, the motor rotor, and inside the battery cells, often lack the conditions for placing temperature sensors.

[0005] For all-in-one power systems that integrate these power components, due to their high degree of integration, they have high requirements for space and volume, and temperature protection is also a key design factor. Currently, inverters, motors, batteries, and cooling pipes are all equipped with multiple temperature sensors. The power supply lines and insulation requirements of the temperature sensors place stringent demands on the structural layout of the power system, the sealing of the cooling circuit, and the low-voltage power supply system. In addition, the temperature sensors have a lag in acquisition and filtering speed under extremely high current conditions, resulting in a lack of rapid protection for the power components of the power system, which can easily lead to thermal runaway. In addition, the complex layout of the temperature sensors, especially the high requirements for process technology, leads to high overall costs.

[0006] Accordingly, the present invention is directed to overcoming one or more of the above-mentioned problems. Summary of the Invention

[0007] In view of the above-mentioned purpose, the present invention provides an all-in-one power system, wherein the power components of the all-in-one power system share a cooling circuit, and the temperature estimation system estimates the temperature of all key power parts and key locations of the entire power system by using the estimated result of the cooling fluid temperature in the cooling fluid flow path as the link for estimating the temperature of the entire power system, so that further control can be performed based on the estimated result, thereby solving the problem of complicated temperature sensor layout process, especially the problems of sealing of the cooling circuit and control cost.

[0008] According to one aspect of the present invention, an all-in-one power system is provided, comprising at least two power units, wherein the at least two power units share a cooling circuit, wherein cooling fluid of the cooling circuit flows sequentially through the at least two power units to cool them, wherein the all-in-one power system comprises a temperature sensor disposed at a node portion of a thermal resistance network associated with a first power unit of the at least two power units, and the all-in-one power system further comprises a controller configured to calculate an electrical value of the power unit, the electrical value comprising a thermal resistance between node portions of the thermal resistance network of the power unit and a power loss at the node portion or a heat loss associated with the thermal resistance.

[0009] The controller is further configured to perform the following steps:

[0010] Step a: obtaining a first cooling fluid temperature associated with a first power unit as a current starting reference temperature, setting the first power unit as a current power unit, and setting a second power unit arranged adjacent to the current power unit on a flow path of the cooling fluid as an adjacent power unit;

[0011] Step b: Based on the current starting reference temperature and based on the electrical values ​​of the current power unit and the upstream power unit, calculating the cooling fluid temperature associated with the adjacent power unit as the intermediate reference temperature;

[0012] Step c: estimating the temperature of each node of the thermal resistance network of the adjacent power unit based on the calculated intermediate reference temperature and the calculated electrical value of the adjacent power unit.

[0013] Advantageously, the temperature of the first cooling fluid is obtained by measuring with a temperature sensor, or estimated based on the temperature of an internal node of a thermal resistance network of the associated first power unit measured by the temperature sensor and a calculated electrical value of the first power unit.

[0014] Advantageously, the all-in-one power system includes a third power unit arranged adjacent to the second power unit on the flow path of the cooling fluid, and the controller is configured to: set the calculated intermediate reference temperature as the current starting reference temperature, set the second power unit as the current power unit, execute step b to calculate the third cooling fluid temperature associated with the third power unit as the intermediate reference temperature, and execute step c to estimate the temperature of each node part of the thermal resistance network of the third power unit.

[0015] Advantageously, each power unit of the all-in-one power system includes one or more power components, and the power components are selected from a battery pack, a motor, an inverter, a gearbox, a reducer, and a DCDC converter.

[0016] Advantageously, the all-in-one power system includes an inverter as a power component, and the temperature sensor is arranged on a PCB board of the inverter as a node position.

[0017] Advantageously, the entire all-in-one power system comprises only a single temperature sensor.

[0018] Advantageously, the cooling fluid is water or cooling oil.

[0019] According to another aspect of the present invention, a temperature estimation method for performing temperature estimation using the all-in-one power system is provided, which comprises the following steps:

[0020] Step a: obtaining a cooling fluid temperature associated with a current power unit as a current starting reference temperature, and setting a power unit arranged adjacent to the current power unit on a flow path of the cooling fluid as an adjacent power unit;

[0021] Step b: Based on the current starting reference temperature and based on the electrical values ​​of the current power unit and the upstream power unit, calculating the cooling fluid temperature associated with the adjacent power unit as the intermediate reference temperature;

[0022] Step c: estimating the temperature of each node of the thermal resistance network of the adjacent power unit based on the calculated intermediate reference temperature and the calculated electrical value of the adjacent power unit.

[0023] Advantageously, step a includes: obtaining the temperature of the cooling fluid associated with the current power unit by measuring through a temperature sensor; or receiving the temperature of the internal node parts of the thermal resistance network associated with the current power unit from the temperature sensor, and estimating the temperature of each node part of the thermal resistance network of the current power unit and the cooling fluid temperature associated with the current power unit based on the measured temperature of the internal node parts and the calculated electrical value of the current power unit.

[0024] Advantageously, the intermediate reference temperature is set as the current starting reference temperature, the power unit associated with the current starting reference temperature is set as the current power unit, and steps b and c are repeated until the temperatures of each node of the thermal resistance network of all power units of the all-in-one power system are obtained.

[0025] A non-transitory computer-readable medium according to the present invention includes instructions, and when the instructions are executed by one or more processors, the method described above is performed.

[0026] According to the all-in-one power system of the present invention, taking the inverter as the upstream of the cooling circuit as an example, the inverter assembly can estimate the temperature of the cooling fluid using a temperature sensor placed on the PCB. This temperature is then used as the temperature input for the motor or battery cooling fluid. A thermal resistance network model or thermal equivalent circuit is then constructed for each power unit based on its inherent physical properties and cooling configuration. This allows the temperature of the nodes of the thermal resistance network of each power unit in the entire all-in-one power system to be estimated using only a single temperature sensor placed in a location easily accessible for sensor placement, such as a PCB.

[0027] The all-in-one power system and temperature estimation method of the present invention reduce the number of temperature sensors required in the power system, avoiding sealing issues caused by placing temperature sensors in the cooling circuit, and avoiding the process problems of placing temperature sensors inside the motor and the resulting low-voltage power supply issues. This reduces process complexity and costs, improves the overall system integration, and facilitates layout and assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Features and advantages of one example of the present invention will become apparent with reference to the following detailed description and accompanying drawings, in which:

[0029] Figure 1 A schematic diagram of a thermal resistance network of an all-in-one power system according to the present invention is shown;

[0030] Figure 2 A schematic diagram showing a thermal resistance network of an inverter of an all-in-one power system according to the present invention is shown;

[0031] Figure 3 A schematic diagram showing a thermal resistance network of a motor of an all-in-one power system according to the present invention; and

[0032] Figure 4 A schematic block diagram showing a temperature estimation method of an all-in-one power system according to the present invention. DETAILED DESCRIPTION

[0033] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0034] The following describes an all-in-one power system and a temperature estimation method implemented therein according to an embodiment of the present invention with reference to the accompanying drawings. The all-in-one power system can be applied to new energy vehicles, such as pure electric vehicles or hybrid electric vehicles.

[0035] Reference Figure 1 As shown, an all-in-one power system 1 according to an embodiment of the present invention includes at least two power units. Each power unit generates power loss during operation, thereby generating heat. In the embodiment shown in the figure, each power unit of the all-in-one power system includes one or more power components, selected from the group consisting of an electronic control unit (inverter PU), a motor MU, a battery BU, a gearbox, a reducer, a DC-DC converter, and the like. Those skilled in the art may integrate other power components into the entire system as needed. All of these power units share a cooling circuit, and the cooling fluid in the cooling circuit flows sequentially through these power units in the direction indicated by the flow direction X to cool them. Herein, a power unit includes power components and cooling fluid and cooling pipes for cooling the corresponding power components. In the embodiment shown, the all-in-one power system includes a temperature sensor disposed at a node in a thermal resistance network associated with the inverter (e.g., the inverter's PCB board, i.e., node P1). The all-in-one power system 1 also includes a controller (not shown) configured to be signal-coupled to all power units and the temperature sensors, thereby receiving temperature values ​​from the temperature sensors and calculating electrical values ​​for all power units. The electrical values ​​include the thermal resistances between nodes of the thermal resistance network of the power unit and the power loss at the nodes or the heat loss associated with the thermal resistances. In the all-in-one power system according to the present invention, the controller is configured to estimate the internal node temperature of each power unit in the thermal resistance network of the entire system and / or the temperature of the cooling fluid associated with each power unit based on the temperature from the temperature sensor and the calculated electrical values.

[0036] Below Figure 1 The embodiment shown in FIG. 1 is used as an example to illustrate how the all-in-one power system of the present invention estimates the internal node temperature of the power unit and the cooling fluid temperature associated with each power unit.

[0037] Figure 1The entire all-in-one power system contains only one temperature sensor. This temperature sensor is located at node P1 (e.g., a printed circuit board) in the inverter's thermal resistance network. The temperature at node P1, measured by the temperature sensor, serves as the current starting reference temperature. For example, the cooling fluid flows first through the inverter PU, then through the motor MU, and then through the battery BU, in the direction indicated by arrow X in the figure. Of course, the order in which the cooling fluid flows through the power components shown in the figure can be changed as needed.

[0038] Figure 1-3 In the figure, hollow or solid circles represent thermal resistance network nodes, and rectangular blocks represent equivalent thermal resistance. Figure 1 The thermal equivalent circuit (ie, thermal resistance network) of the entire all-in-one power system is schematically shown.

[0039] Figure 2 The thermal equivalent circuit of an exemplary embodiment of an inverter is shown separately. When the inverter is operating, three components of the inverter constitute the primary heat sources: the PCB (i.e., node P1), the diode (i.e., node P2), and the IGBT (i.e., node P3). Heat loss Q1 occurs at the PCB, Q2 at the diode, and Q3 at the IGBT. The temperature T1 measured by the sensor at node P1 represents the temperature of the PCB. A thermal resistance R1 exists in the heat flow path between node P1 and the heat exchanger (i.e., node P4), hindering direct heat flow to the heat exchanger. Similarly, a thermal resistance R2 exists in the heat flow path between the diode (i.e., node P2) and the heat exchanger (i.e., node P4), and a thermal resistance R3 exists in the heat flow path between the IGBT (i.e., node P3) and the heat exchanger (i.e., node P4). A thermal resistance R4 exists in the heat flow path between the heat exchanger (i.e., node P4) and the ambient environment (i.e., the cooling fluid, i.e., node P).

[0040] Although Figure 2 shows an example of an inverter's thermal equivalent circuit. However, the shape of the inverter's thermal equivalent circuit is determined by the inverter's internal structure and the drafter's intentions. In other words, as the inverter's internal structure becomes more complex, the thermal equivalent circuit generally becomes more complex. However, even when the inverter's internal structure is complex, if the designer considers computational feasibility to be more important than the accuracy of the thermal equivalent circuit, the thermal equivalent circuit can be constructed more simply.

[0041] The total power loss of the inverter is ultimately carried away by the cooling fluid as heat. The formula for calculating total power loss can be divided into steady-state loss, drive loss, and switching loss. Steady-state loss is divided into conduction loss and cutoff loss, while switching loss is divided into turn-on loss and turn-off loss. These power losses can be calculated using existing formulas.

[0042] In this article, thermal resistance Ri (i=1, 2, 3, ...) can be divided into heat conduction type thermal resistance and convection type thermal resistance.

[0043] Thermal resistance R k It can be expressed by the following formula (1) through Fourier's law of heat conduction: Wherein, k is the thermal conductivity, L is the length of the conductive material, and A1 is the area of ​​the conductive material.

[0044]

[0045] In addition, the convection heat transfer thermal resistance R convection It can be indicated by the following formula (2).

[0046]

[0047] in, is the unit heat convection conduction or average convection heat transfer coefficient, and A2 is the surface area in contact with the fluid.

[0048] The choice of formula (1) and formula (2) is based on the specific heat transfer type.

[0049] The basic heat transfer equation indicated by the following equation (3) is used to estimate the temperature of each thermal resistance network node.

[0050]

[0051] Where ΔT is the change in temperature (thermal resistance R i The temperature difference between the nodes at both ends), Ri is the thermal resistance, Q i (i=1, 2, 3, ...) is the combined heat flow of each or part or all of the lost heat Q1, Q2, and Q3, ... (for example, Q4=Q1+Q2+Q3).

[0052] For the inverter, to calculate heat losses Q1, Q2, and Q3, power loss models must be constructed for the PCB, diodes, and IGBTs. Electrical values ​​such as current and voltage of each component during inverter operation can be used to calculate power losses. To simplify and facilitate analysis, the power losses of the PCB, diodes, and IGBTs can be considered to be converted into heat losses. Of course, a conversion factor can also be added to represent the conversion rate from power loss to heat loss, depending on the actual situation.

[0053] The following briefly describes the method of applying formula (3) to the inverter power unit.

[0054] When the temperature sensor senses the temperature T1 of the PCB, the controller retrieves or calculates the electrical value of the PCB from the memory, calculates the heat loss Q1, and calculates the temperature T4 of the heat exchanger at the node P4 using formula (3).

[0055] Then, the temperature T2 of the node P2 (ie, the diode temperature) is calculated using formula (3).

[0056] Similarly, the temperature T3 of the node P3 (ie, the temperature of the IGBT) is calculated.

[0057] The local ambient temperature around the inverter (ie, the cooling fluid temperature) Tp = T4 - Q4 x R4. In the all-in-one power system of the present invention, Tp can be regarded as the cooling fluid temperature discharged from the inverter into the next power unit (ie, the motor).

[0058] Specifically, after determining the heat flow rate for each of the lost heats Q1, Q2, and Q3, or the combined lost heat, the heat flow rate is multiplied by the thermal resistance value to obtain the temperature change ΔT. The flow state of the lost heat varies depending on the specific thermal resistance network model. Information related to the flow state of the lost heat can be stored as an electrical value.

[0059] Back to Figure 1 , it can be seen that the thermal resistance network model of the inverter is different from Figure 2 The thermal resistance network model shown in Figure 2 can vary significantly depending on the heat flow state and the specific inverter structure design. However, using the calculation method described above, by accessing the corresponding electrical values ​​(including parameters such as thermal resistance), the temperatures of all other nodes in the thermal resistance network can be estimated, even if only the temperature of one node in the network model is known (usually obtained through a sensor placed in an easily accessible location).

[0060] In the motor MU located downstream of the inverter along the flow direction X of the cooling fluid, the thermal equivalent circuit is as follows: Figure 3 See Figure 1 In the thermal resistance network of the entire system shown, the cooling fluid temperature at node M can be calculated based on the temperature at node P. The thermal resistance between nodes P and M is determined by parameters such as the pipe length, heat exchange area, pipe material thermal conductivity, and cooling fluid flow rate in the pipe. When the cooling fluid flow rate is sufficiently high, the thermal resistance between nodes M and P is negligible, meaning that the cooling fluid temperature Tp at node P is nearly equal to the cooling fluid temperature Tm at node M. The heat flow rate along the heat flow path between nodes P and M can be calculated based on the electrical values ​​of the inverter.

[0061] Next, the cooling fluid temperature at the node M is used as the current starting reference temperature to estimate the temperature of all nodes of the entire motor MU. Figure 3The thermal equivalent circuit of the motor unit MU is shown below. Node M represents the cooling fluid, node M1 represents the stator yoke, node M2 ​​represents the stator teeth, node M3 represents the rotor teeth, node M4 represents the rotor yoke, node M5 represents the bearing, node M6 represents the winding center, and node M7 represents the winding end. Other nodes may be configured depending on the specific motor configuration. Figure 3 The thermal resistance between adjacent nodes and the flow state of lost heat are shown in FIG. As the specific motor configuration is different, the corresponding thermal equivalent circuit can also be drawn with different layouts.

[0062] refer to Figure 3 As shown in the figure, each node in the motor represents a component that will generate a certain amount of power loss. It is assumed that these power losses are eventually converted into heat loss and carried away by the cooling fluid.

[0063] The power loss of a motor is mainly divided into stator winding (or copper) loss, core (or iron) loss and rotor windage loss.

[0064] The power loss of the stator winding is calculated by formula (4):

[0065] P winding =I 2 ×R formula (4)

[0066] Among them, P winding is the winding power loss, I is the current, and R is the resistance of the winding.

[0067] Core loss can be calculated using the following formula:

[0068] P iron =P h +P e Formula (5)

[0069] Among them, P iron For P h is the power loss caused by hysteresis loss, P e is the power loss due to eddy current loss.

[0070] The windage loss of the rotor can be calculated according to the following formula:

[0071] P wind =kC f ρnω m 3 R 4 L Formula (6)

[0072] Among them, P wind is the windage loss of the rotor, k represents the surface roughness of the rotor, and when the surface is smooth, k is taken as 1, C fis the friction coefficient, which depends on the velocity and the properties of the gas; ρ is the gas density; ω m is the angular velocity of the rotor, R is the radius of the rotor, and L is the length of the rotor.

[0073] Based on the motor's thermal resistance network configuration, the flow of lost heat is determined. Based on the temperature Tm at node M and the motor's electrical values, the temperatures of nodes M1, M2, M3, M4, M5, M6, and M7 are calculated. Since these nodes are often located where it's not practical to install temperature sensors or other temperature sensing devices, the temperature estimation method of the present invention eliminates the need for temperature sensors. Furthermore, due to its high calculation speed, the temperature of each internal node in the motor's thermal resistance network can be estimated in real time, avoiding any delays or errors caused by temperature sensor installation.

[0074] The battery is located downstream of the electric machine in the flow path of the cooling fluid. Based on the cooling fluid temperature at node M of the electric machine and based on the electrical values ​​of the electric machine and the inverter, the cooling fluid temperature at node B associated with the battery is inferred.

[0075] In one example, the battery unit includes a battery pack consisting of multiple battery cells (not shown). The nodes of the battery's thermal resistance network are individual battery cells, copper busbars, cooling plates, cooling fluid, etc. The battery unit includes multiple nodes. The thermal flow model of the battery's thermal resistance network can be obtained through experimentation or experience.

[0076] The heat loss of the battery can be calculated according to the following formula:

[0077] P 节点 =I 节点 ×I 节点 ×R 节点 Formula (7)

[0078] P 节点 is the power loss at the corresponding node, I 节点 is the current at the node component, R 节点 is the resistance of the node component.

[0079] refer to Figure 1 In the thermal resistance network of the entire power system shown, after determining the temperature Tm at node M, the temperature Tb at node B can be calculated or derived. When the cooling fluid flow rate is high, the thermal resistance between nodes M and B can be ignored. That is, temperature Tm is equal to temperature Tb. Based on the flow of heat loss from the battery, the heat flow rate of the heat flow path from node Bi / Bj to node B / B0 is calculated, and from this, the temperature at node Bi or node B0 can be further derived. This process continues in this way until the temperatures of all nodes in the battery thermal resistance network are calculated.

[0080] Similarly, if there are other power components downstream of the battery, such as a DCDC converter, after calculating the temperature at node B0, the temperature of the cooling fluid associated with the DCDC converter is calculated based on the electrical values ​​of the inverter, motor and battery, and then the temperature of the internal node of the thermal resistance network of the power unit where the DCDC converter is located is calculated.

[0081] By analogy, the temperature of each node of the thermal resistance network of the entire all-in-one power system can be estimated.

[0082] The cooling fluid temperature estimation can be calculated from upstream to downstream, or from downstream to upstream.

[0083] Although the thermal resistance network of the power system is used to estimate the temperature of each node in the above embodiment, the power system of the present invention is not limited to the power system shown.

[0084] In addition, the above description of the temperature estimation method of the present invention only uses the thermal resistance network model method to calculate the temperature of the internal nodes of each power unit. However, the temperature estimation method of the present invention can also use other calculation methods, such as a combination of a thermal resistance network model and a neural network algorithm, to improve the estimation accuracy.

[0085] The following combination Figure 4 To illustrate the working principle of the all-in-one power system of the present invention and the temperature estimation method adopted therein.

[0086] A temperature sensor is installed at any node in the thermal resistance network of any power unit of the all-in-one power system of the present invention. The node location for installing the temperature sensor can be selected based on factors such as ease of installation and measurement accuracy. The power unit where the temperature sensor is located is considered the current power unit.

[0087] In step S100 , the temperature sensor measures the temperature of the node where the current power unit is located.

[0088] In step S101, the temperatures of each node in the thermal resistance network of the current power unit, including the temperature of the cooling fluid associated with the current power unit, are calculated based on the measured node temperatures. If a temperature sensor directly measures the temperature of the cooling fluid associated with the current power unit, the temperatures of each internal node of the thermal resistance network of the entire current power unit can also be calculated based on the measured temperatures.

[0089] In step S102 , the temperature of the cooling fluid associated with the current power unit is set as the current starting reference temperature.

[0090] Next, in step S103, the controller determines whether the calculation of the thermal resistance network node temperatures of all power units is completed. If the determination in step S103 is No, the process proceeds to step S104. If the determination in step S103 is Yes, the method ends.

[0091] When the determination in step S103 is No, step S104 is performed, that is, based on the current starting reference temperature and the electrical values ​​of the current power unit and the upstream power unit, the cooling fluid temperature associated with the next adjacent / previous adjacent power unit is calculated as the intermediate reference temperature.

[0092] In step S105 , based on the intermediate reference temperature and the electrical value of the next adjacent / previous adjacent power unit, the temperature of each node of the thermal resistance network of the next adjacent / previous adjacent power unit is estimated.

[0093] Next, in step S106, the next adjacent / previous adjacent power unit is set as the current power unit, and the intermediate reference temperature is set as the current starting reference temperature.

[0094] In step S107, the controller determines whether there is a next adjacent / previous adjacent power unit whose temperature has not been calculated. If so, the program enters step S104 and executes steps S104 to S106. If not, it enters step S102, takes the current power unit as the base point and sets the cooling fluid temperature of the current power unit as the current starting reference temperature, and then performs step S103 to search whether there is a power unit whose thermal resistance network node temperature has not been calculated. If there is still a power unit whose temperature has not been calculated, it enters step S104 for calculation. At this time, the calculation direction may be calculated from upstream to downstream relative to the flow path of the cooling fluid, or it may be calculated from downstream to upstream. The specific calculation direction can be determined according to the position of the power unit whose node temperature has not been calculated relative to the current power unit.

[0095] The calculation procedure is repeated until the temperature calculation of all the nodes of the thermal resistance network of the power unit is completed.

[0096] It should be noted that the logic and / or steps represented in the computational flow charts of the present invention or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing the logical functions, and can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device (e.g., a computer-based system, a system including a processor, or other system that can fetch and execute instructions from an instruction execution system, apparatus, or device), or in conjunction with such instruction execution system, apparatus, or device. For the purposes of this specification, "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transmit a program for use by an instruction execution system, apparatus, or device, or in conjunction with such instruction execution system, apparatus, or device.

[0097] It should be understood that each part of the present invention can be implemented by hardware, software, firmware or a combination thereof. In the above embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system.

[0098] Furthermore, the functional units in the various embodiments of the present invention may be integrated into a single processing module, each unit may exist physically separately, or two or more units may be integrated into a single module. The aforementioned integrated modules may be implemented in the form of hardware or software functional modules.

[0099] The foregoing merely describes an exemplary embodiment of an all-in-one power system according to the present invention. The all-in-one power system according to the present invention is not limited to the specific embodiments described herein. References throughout this specification to "an example," "another example," "an example," and the like, mean that a description of an element / element associated with the example (e.g., a feature, structure, and / or characteristic) is included in at least one example described herein and may and / or may not appear in other examples. In addition, it will be understood that multiple elements of any example described may be combined in any suitable manner in multiple different examples, unless the context clearly indicates otherwise.

[0100] The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.

Claims

1. An all-in-one power system comprising at least two power units, wherein the at least two power units share a cooling circuit, wherein cooling fluid of the cooling circuit flows through the at least two power units in sequence to cool them, wherein: The all-in-one power system includes a temperature sensor disposed at a node of a thermal resistance network associated with a first power unit of the at least two power units, and the all-in-one power system further includes a controller configured to calculate an electrical value of the power unit, the electrical value including a thermal resistance between nodes of the thermal resistance network of the power unit and a power loss at the node or a heat loss associated with the thermal resistance. The controller is further configured to perform the following steps: Step a: obtaining a first cooling fluid temperature associated with a first power unit as a current starting reference temperature, setting the first power unit as a current power unit, and setting a second power unit arranged adjacent to the current power unit on a flow path of the cooling fluid as an adjacent power unit; Step b: Based on the current starting reference temperature and based on the electrical values ​​of the current power unit and the upstream power unit, calculating the cooling fluid temperature associated with the adjacent power unit as the intermediate reference temperature; as well as Step c: estimating the temperature of each node of the thermal resistance network of the adjacent power unit based on the calculated intermediate reference temperature and the calculated electrical value of the adjacent power unit.

2. The all-in-one power system according to claim 1, characterized in that: The temperature of the first cooling fluid is obtained by measuring with a temperature sensor, or is estimated based on the temperature of an internal node of a thermal resistance network of the associated first power unit measured by the temperature sensor and the calculated electrical value of the first power unit.

3. The all-in-one power system according to claim 1 or 2, characterized in that: The all-in-one power system includes a third power unit arranged adjacent to the second power unit on a flow path of the cooling fluid, The controller is configured to set the calculated intermediate reference temperature as the current starting reference temperature, set the second power unit as the current power unit, execute step b to calculate the third cooling fluid temperature associated with the third power unit as the intermediate reference temperature, and execute step c to estimate the temperature of each node of the thermal resistance network of the third power unit.

4. The all-in-one power system according to claim 3, characterized in that: Each power unit of the all-in-one power system includes one or more power components, and the power components are selected from a battery pack, a motor, an inverter, a gearbox, a reducer, and a DCDC converter.

5. The all-in-one power system according to claim 4, characterized in that: The all-in-one power system includes an inverter as a power component, and the temperature sensor is arranged on a PCB board of the inverter as a node position.

6. The all-in-one power system according to claim 1, characterized in that: The entire all-in-one power system only includes a single temperature sensor.

7. The all-in-one power system according to claim 1, characterized in that: The cooling fluid is water or cooling oil.

8. A temperature estimation method for performing temperature estimation using the all-in-one power system according to any one of claims 1 to 7, comprising the following steps: Step a: obtaining a cooling fluid temperature associated with a current power unit as a current starting reference temperature, and setting a power unit arranged adjacent to the current power unit on a flow path of the cooling fluid as an adjacent power unit; Step b: Based on the current starting reference temperature and based on the electrical values ​​of the current power unit and the upstream power unit, calculating the cooling fluid temperature associated with the adjacent power unit as the intermediate reference temperature; as well as Step c: estimating the temperature of each node of the thermal resistance network of the adjacent power unit based on the calculated intermediate reference temperature and the calculated electrical value of the adjacent power unit.

9. The temperature estimation method according to claim 8, characterized in that: Step a includes: Obtaining the temperature of the cooling fluid associated with the current power unit by measuring with a temperature sensor; or The temperature of the internal node parts of the thermal resistance network of the associated current power unit is received from the temperature sensor, and the temperature of each node part of the thermal resistance network of the current power unit and the cooling fluid temperature associated with the current power unit are estimated based on the measured temperature of the internal node parts and the calculated electrical value of the current power unit.

10. The temperature estimation method according to claim 8 or 9, characterized in that: The intermediate reference temperature is set as the current starting reference temperature, the power unit associated with the current starting reference temperature is set as the current power unit, and steps b and c are repeated until the temperatures of the node parts of the thermal resistance network of all power units of the all-in-one power system are obtained.

11. A non-transitory computer-readable medium comprising instructions, which, when executed by one or more processors, perform the temperature estimation method according to any one of claims 8 to 10.

Images