A parameter estimation method of a motor controller

Abstract

The application relates to a junction temperature, water temperature and flow parameter estimation method of a motor controller, characterized in that the method comprises the following steps: step one, calculating the loss of a power component; step two, estimating the flow of cooling water according to the collected temperature of U-phase and W-phase power components and the calculated loss; step three, estimating the U-phase, V-phase and W-phase cooling water temperature according to the collected temperature of U-phase, V-phase and W-phase power components, the calculated loss and the estimated cooling flow; and step four, estimating the junction temperature of the power component according to the collected power component temperature, the calculated loss, the cooling water flow and the temperature. Compared with the prior art, the application has the advantages of not relying on temperature sensors and flow sensors to detect the temperature and flow, and reducing the whole vehicle cost.

Description

Technical Field

[0001] This invention relates to the field of motor control technology, and in particular to a method for estimating parameters of a motor controller. Background Technology

[0002] In the main drive motor controller of new energy vehicles, 50% of power electronic device failures are caused by thermal failure of power components. Especially for new energy vehicles operating in complex environments, they inevitably face extreme conditions such as heavy-load hill starts, 0-100 km / h acceleration, and stall conditions, which undoubtedly increase the risk of controller overheating. Currently, there are two methods for thermal protection of power components: one is to determine the risk of overheating based on operating conditions such as coolant temperature, coolant flow rate, bus voltage, speed, and current; the other is to perform junction temperature estimation. In junction temperature estimation, the coolant flow rate and temperature are the inputs to the model, and the controller will determine whether the power components are at risk of overheating based on the estimated junction temperature.

[0003] Coolant flow rate and temperature are the inputs for both methods mentioned above. Therefore, to implement the aforementioned thermal protection strategy, coolant flow rate and temperature sensors must be installed on the vehicle or the controller. The installation of these sensors undoubtedly increases the cost of the vehicle and the motor controller. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art by providing a method for estimating the parameters of a motor controller.

[0005] The objective of this invention can be achieved through the following technical solutions:

[0006] A method for estimating parameters of a motor controller, the method comprising the following steps:

[0007] Step 1: Calculate the power losses of the power components;

[0008] Step 2: Estimate the cooling water flow rate based on the collected temperatures of the U-phase and W-phase power components and the calculated losses;

[0009] Step 3: Based on the collected temperatures of the power components in phases U, V, and W, the calculated losses, and the estimated cooling flow rate, estimate the cooling water temperatures for phases U, V, and W.

[0010] Step 4: Estimate the junction temperature of the power components based on the collected power component temperatures, calculated losses, cooling water flow rate and temperature.

[0011] Furthermore, the losses of the power components are calculated based on the bus voltage, phase current, duty cycle, switching frequency, and estimated junction temperature. The losses of the power components include IGBT losses and diode losses.

[0012] P = P i +P d

[0013] In the formula, P represents the power loss of the power components. i For the losses of IGBT, P d This represents the diode's loss.

[0014] Furthermore, the IGBT losses include: IGBT conduction losses and IGBT switching losses.

[0015] P i =P ic +P is

[0016] P ic =V ids I C D

[0017] P is =F s u dc (k io +k i1 I C +k i2 I C ^2)

[0018] In the formula, P i For the losses of IGBT, P ic For the conduction loss of the IGBT, P is V represents the switching losses of the IGBT. ids I is the source-drain voltage of the IGBT. C Where D is the instantaneous value of the phase current, and F is the duty cycle. s U is the switching frequency. dc For bus voltage, k i0 k i1 and k i2 For IGBT switching losses at 0, 1, and 2 cycles;

[0019] The diode losses include: the diode's conduction losses and the diode's reverse recovery losses.

[0020] P d =P dc +P dr

[0021] P dc =V dds I C (1-D)

[0022] P dr =F s udc (k d0 +k d1 I C +k d2 I C ^2)

[0023] In the formula, P d For the diode loss, P dc For diode conduction loss, P dr For the reverse recovery loss of the diode, V dds I is the forward voltage drop of the diode. C Where D is the instantaneous value of the phase current, and F is the duty cycle. s U is the switching frequency. dc For bus voltage, k d0 k d1 and k d2 These are the coefficients for diode switching losses at 0 cycles, 1 cycle, and 2 cycles, respectively.

[0024] Furthermore, the step of estimating the cooling water flow rate in step two includes:

[0025] Based on the power component losses calculated in step one, the collected temperatures of the U-phase and W-phase, and the cooling water temperature rise model, and using the model reference adaptive algorithm, the temperature difference between the collected U-phase and W-phase temperature sensors and the temperature difference between the U-phase and W-phase temperature sensors estimated by the cooling water temperature rise model are used to achieve a closed-loop temperature estimation, thereby estimating the cooling water flow rate.

[0026] Furthermore, the mathematical expression for the cooling water temperature rise model is:

[0027]

[0028] y f =C f x f

[0029] In the formula, x f Let x be the state variable of the system. f =[x j1 -x f2 x f2 -x f3 x f3 -T u ] T ;y f For the system output, y f =T w -T u ;u f u is the input to the system. f =P,T w and T uTemperatures collected for phase W and phase U are represented by matrix A. f B f C f for:

[0030]

[0031]

[0032] C f =[1 1 1]

[0033] In the formula, R f1 C f1 R f2 C f2 R f3 C f3 These are parameters related to the flow direction of the cooling water. These parameters are related to the flow rate of the cooling water, and the parameter values ​​for each flow rate are pre-calibrated.

[0034] Furthermore, the step of estimating the cooling water temperature in step three includes:

[0035] Based on the power component losses calculated in step one, the cooling water flow estimated in step two, the phase temperatures collected by the temperature sensors, and the thermal model of the temperature sensors, a model reference adaptive algorithm is used to realize the temperature difference between the temperature detected by the temperature sensors of each phase and the estimated water temperature of each phase, and the temperature difference between the estimated controller temperature of each phase and the estimated water temperature of each phase, thus estimating the cooling water temperature of each phase.

[0036] Furthermore, the mathematical expression for the thermal model of the temperature sensor is:

[0037]

[0038] y t =C t x t

[0039] In the formula x t The state variables of the system are x t =[x t1 -x t2 x t2 -x t3 x t3 -T u_cool ] T ;y t For the system output, y t =T u -T u_cool ;u t u is the input to the system. t= P matrix A t B t C t for

[0040]

[0041]

[0042] C t =[1 1 1]

[0043] In the formula, R t1 C t1 R t2 C t2 R t3 C t3 These are thermal parameters related to the cooling water temperature, and their parameters are related to the cooling water flow rate. The thermal parameters related to the cooling water temperature for each flow rate are pre-calibrated.

[0044] Furthermore, the step of estimating the junction temperature of the power components in step four includes:

[0045] Based on the losses calculated in step one, the cooling water flow estimated in step two, the cooling water temperature of each phase estimated in step three, the temperature of each phase collected by the temperature sensor, and the junction temperature estimation thermal model, the temperature difference between the collected temperature of each phase controller and the estimated water temperature, and the temperature difference between the estimated temperature of each phase controller and the estimated water temperature are used to perform a temperature closed loop to estimate the junction temperature of each phase power component.

[0046] Furthermore, the junction temperature estimation thermal model is as follows:

[0047]

[0048] y = Cx

[0049] In the formula, x is the state variable of the system, x = [x j1 -x j2 x j2 -x j3 x j3 -T u_cool x t1 -x t2 x t2 -x t3 x t3 -T u_cool ] T ; y is the system output, y = [T j -T u_cool T u -T u_cool ] Tu is the system input, u = P, and matrices A, B, and C are respectively:

[0050]

[0051]

[0052]

[0053] In the above formula, R j1 C j1 R j2 C j2 R j3 C j3 R is the junction temperature-dependent thermal model parameter. t1 C t1 R t2 C t2 R t3 C t3 These are thermal parameters related to the cooling water temperature. The values ​​of the two thermal parameters are related to the cooling water flow rate, and the thermal parameter value corresponding to each flow rate is pre-calibrated.

[0054] Furthermore, the mathematical model for estimating the junction temperature of each power component in a single phase of the motor using the aforementioned observer is as follows:

[0055]

[0056]

[0057] In the above formula, This is an estimate of the system state. z is the observed signal. For the estimated observed signal, T u The temperature of this phase detected by the temperature sensor. To estimate the cooling water temperature of this phase, A and B are coefficient matrices, L is the observer matrix, and H is the observation matrix, which are respectively:

[0058]

[0059] H = [0 0 0 1 1 1]

[0060] In the above formula, l1, l2, l3, l4, l5, and l6 are the observer parameters;

[0061] Then the estimated junction temperature Represented as:

[0062]

[0063] In the above formula, D is the output matrix:

[0064] D = [1 1 1 0 0 0].

[0065] Compared with the prior art, the present invention has the following beneficial effects:

[0066] (i) This invention proposes a method for estimating junction temperature, coolant temperature, and coolant flow rate without relying on temperature and flow sensors for the coolant to detect the temperature and flow rate, and for estimating the junction temperature. When the vehicle or controller performs thermal management, it is not necessary to install coolant flow and temperature sensors, thereby significantly reducing the overall vehicle cost.

[0067] (ii) New energy vehicles equipped with the motor controller parameter estimation method provided by this invention can still perform junction temperature estimation normally in the event of failure of temperature sensor and flow sensor, thereby improving the safety of vehicle system. Attached Figure Description

[0068] Figure 1 This is a schematic diagram of the process of the present invention;

[0069] Figure 2 A schematic diagram illustrating the principle of estimating junction temperature, water temperature, and flow rate of a motor controller, provided in an embodiment of the present invention;

[0070] Figure 3 A schematic diagram of the controller structure is provided for an embodiment of the present invention;

[0071] Figure 4 A schematic diagram of the power component structure is provided for embodiments of the present invention;

[0072] Figure 5 A schematic diagram of the cooling water temperature rise model for power components is provided for embodiments of the present invention;

[0073] Figure 6 A schematic diagram for estimating the cooling water flow rate of power components is provided for embodiments of the present invention;

[0074] Figure 7 A schematic diagram of a temperature sensor thermal model for power components is provided for embodiments of the present invention.

[0075] Figure 8 A schematic diagram for estimating the cooling water temperature of power components is provided for embodiments of the present invention;

[0076] Figure 9 A schematic diagram of a thermal model for estimating the junction temperature of power components is provided for embodiments of the present invention;

[0077] Figure 10 A schematic diagram for estimating the junction temperature of power components is provided for embodiments of the present invention;

[0078] The numbers in the diagram are as follows:

[0079] 1. Power component chip; 2. Power component bonding wire; 3. Copper; 4. Temperature sensor (NTC) used to detect the controller temperature; 5. Solder layer; 6. Power component package; 7. Power component heat dissipation section. Detailed Implementation

[0080] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. These embodiments are based on the technical solution of the present invention and provide detailed implementation methods and specific operating procedures. However, the scope of protection of the present invention is not limited to the following embodiments.

[0081] The main problem solved by this invention is to estimate junction temperature, cooling water temperature, and cooling water flow rate in the absence of cooling water temperature and flow sensors, including the following steps:

[0082] Step 1: Calculate the power component losses. Calculate the power component losses based on the bus voltage, phase current, duty cycle, switching frequency, and estimated junction temperature.

[0083] Step 2: Estimate the cooling water flow rate. Based on the losses calculated in Step 1, the collected temperatures of phase U and phase W, and the cooling water temperature rise heat model, a closed-loop temperature measurement is achieved using the model reference adaptive algorithm to calculate the temperature difference between the collected phase U and phase W temperature sensors and the temperature difference estimated by the cooling water temperature rise heat model, thereby estimating the cooling water flow rate.

[0084] Step 3: Estimate the temperature of each phase of cooling water. Based on the power component losses calculated in Step 1, the cooling water flow rate estimated in Step 2, the phase temperatures collected by the temperature sensors, and the thermal model of the temperature sensors, a model reference adaptive algorithm is used to realize a closed-loop temperature estimation between the temperature detected by the temperature sensors of each phase and the estimated water temperature of each phase, and between the estimated controller temperature of each phase and the estimated water temperature of each phase.

[0085] Step 4: Estimate the junction temperature of power components. Based on the losses calculated in Step 1, the cooling water flow rate estimated in Step 2, the cooling water temperature of each phase estimated in Step 3, the phase temperatures collected by temperature sensors, and the junction temperature estimation thermal model, an observer is used to achieve a closed-loop temperature measurement between the collected phase controller temperatures and the estimated water temperatures, and between the estimated phase controller temperatures and the estimated water temperatures, thereby estimating the junction temperature of each phase power component.

[0086] This invention patent is mainly applied to the estimation of junction temperature, cooling water flow rate, and cooling water temperature of motor controllers, especially for the estimation of junction temperature, water temperature, and flow rate of the main drive controller in new energy vehicles. Its basic principle is illustrated in the schematic diagram below. Figure 2 As shown.

[0087] Figure 3 This is a schematic diagram of a motor controller for a new energy vehicle. The three-phase power components U, V, and W are used to control the three-phase current, with phase U being closer to the inlet and phase W being closer to the outlet.

[0088] Figure 4 The diagram shows the power components of the controller under study. In the diagram, 1 is the chip of the power component, 2 is the bonding wire of the power component, 3 is copper, 4 is the temperature sensor (NTC) used to detect the temperature of the controller, 5 is the solder layer, 6 is the package of the power component, and 7 is the heat dissipation part of the power component.

[0089] When current flows through a power component, losses are inevitable. These losses occur through the chip-to-power component packaging structure and are ultimately dissipated through the heat sink, causing the component's temperature to rise throughout the process. This temperature rise includes lateral and longitudinal temperature rises. The lateral temperature rise is caused by losses leading to an increase in the cooling water temperature; a lateral thermal model is used for this. The longitudinal temperature rise is caused by losses affecting the power component and NTC; a longitudinal thermal model is used for this. This invention patent is based on the characteristics of these lateral and longitudinal thermal models.

[0090] A method for estimating junction temperature, water temperature, and flow rate of a motor controller, mainly including functions for estimating cooling water temperature, cooling water flow rate, and junction temperature, comprising the following steps:

[0091] Step 1: Calculate the power losses of the components.

[0092] The losses of power components, including the conduction loss of IGBTs, the switching loss of IGBTs, the conduction loss of diodes, and the reverse recovery loss of diodes, are mathematically modeled as follows:

[0093] P = P i +P d

[0094] P i =P i c+P i s

[0095] P ic =V ids I C D

[0096] P is =F s u dc (ki0 +k i1 I C +k i2 I C ^2)

[0097] P d =P dc +P dr

[0098] P dc =V dds I C (1-D)

[0099] P dr =F s u dc (k d0 +k d1 I C +k d2 I C ^2)

[0100] In the formula, P represents the power loss of the power components. i For the losses of IGBT, P d For the diode loss, P ic For the conduction loss of the IGBT, P is For the switching losses of IGBT, I C V is the instantaneous value of the phase current. ids Where D is the source-drain voltage of the IGBT, and F is the duty cycle. s U is the switching frequency. dc For bus voltage, k i0 k i1 and k i2 P represents the coefficients for IGBT switching losses at zero, first, and second cycles. dc For diode conduction loss, P dr For the reverse recovery loss of the diode, V dds k is the diode forward voltage drop. d0 k d1 and k d2 The coefficients for diode switching losses at zero, first, and second cycles are given.

[0101] Step 2: Estimate the cooling water flow rate.

[0102] When the electronic control system is operating, power components will generate losses, which will cause the coolant temperature to rise along the inlet to the outlet. This temperature rise process can be represented by a third-order RC thermal model, such as... Figure 5 As shown. Its mathematical model can be expressed by the following formula:

[0103]

[0104] y f =C f x f

[0105] In the formula x f Let x be the state variable of the system. f =[x f1 -x f2 x j2 -x j3 x j3 -T u ] T ;y f For the system output, y f =T w -T u ;u f u is the input to the system. f =P, matrix A f B f C f for

[0106]

[0107]

[0108] C f =[1 1 1]

[0109] In the formula, R f1 C f1 R f2 C f2 R f3 C f3 The parameters related to the flow direction of the cooling water are related to the flow rate of the cooling water, and it is necessary to calibrate the values ​​of these parameters for each flow rate.

[0110] Figure 6 This invention patent proposes a flow estimation method, where T in the figure... w -T u The detected temperature difference between the W and V phases, To estimate the temperature difference between the W and U phases, For the estimated cooling water flow rate, The estimated junction temperature is calculated based on the detected temperature difference between the U and W phases and the temperature difference between the U and W phases estimated by the thermal model. A temperature closed loop is implemented using the Model Reference Adaptive Algorithm (MRAS) to finally estimate the cooling water flow rate.

[0111] Step 3: Estimate the temperature of each phase of cooling water.

[0112] Electrical losses will cause the NTC temperature to rise. Cooling water temperature estimation includes the estimation of the three-phase cooling water (U-phase, V-phase, and W-phase). The estimation principle for the three-phase cooling water is the same. The following uses the U-phase as an example to explain the estimation principle of the U-phase cooling water temperature.

[0113] The temperature rise of the NTC caused by losses can be represented by a third-order thermal model, such as... Figure 7 As shown, the entire temperature rise process can be described using a state equation.

[0114]

[0115] y t =C t x t

[0116] In the formula x t The state variables of the system are x t =[x t1 -x t2 x t2 -x t3 x t3 -T u_cool ] t ;y t For the system output, y t =T u -T u_cool ;u f u is the input to the system. t =P, matrix A t B t C t for:

[0117]

[0118]

[0119] C t =[1 1 1]

[0120] In the formula, R t1 C t1 R t2 C t2 R t3 C t3 These are thermal parameters related to the cooling water flow rate. The parameters are related to the cooling water flow rate, and it is necessary to calibrate the values ​​of these parameters for each flow rate.

[0121] Figure 8 This invention patent proposes a method for estimating cooling water temperature. (See figure.) T is the cooling water flow rate estimated in step two. uThe temperature of phase U detected by the temperature sensor. For the estimated U-phase temperature, The estimated U-phase cooling water temperature is calculated based on the temperature difference between the detected U-phase temperature and the estimated U-phase cooling water temperature. A temperature closed-loop is implemented using the Model Reference Adaptive Algorithm (MRAS) to ultimately estimate the cooling water temperature.

[0122] Step 4: Estimate the junction temperature of power components

[0123] The losses generated by electronic control will cause the temperature of power components to rise. The temperature rise process can be represented by a third-order RC model, such as... Figure 9 As shown.

[0124] Junction temperature estimation includes the estimation of junction temperatures for three-phase power components (U, V, and W). This invention patent only uses the U phase as an example to illustrate the principle of junction temperature estimation; the principles for the other two phases are basically the same.

[0125] The mathematical model for estimating junction temperature can be represented by a state equation.

[0126]

[0127] y = Cx

[0128] In the formula, x is the state variable of the system, x = [x j1 -x j2 x j2 -x j3 x j3 -T u_cool x t1 -x t2 x t2 -x t3 x t3 -T u_cool ] T ; y is the system output, y = [T j -T u_cool T u -T u_cool ] T u is the system input, u = P, and matrices A, B, and C are respectively:

[0129]

[0130]

[0131]

[0132] In the above formula, R j1 C j1 R j2 Cj2 R j3 C j3 These are the thermal model parameters related to the junction temperature, and their values ​​are related to the cooling water flow rate. It is necessary to calibrate these parameter values ​​for each flow rate.

[0133] Figure 10 This invention patent proposes a junction temperature estimation method that uses an observer to estimate the junction temperature of power components. Its mathematical model is as follows:

[0134]

[0135]

[0136] In the above formula, This is an estimate of the system state. z is the observed signal. For the estimated observed signal, L is the observer matrix, and H is the observation matrix, respectively.

[0137]

[0138] H = [0 0 0 1 1 1]

[0139] In the above formula, l1, l2, l3, l4, l5, and l6 are the observer parameters.

[0140] Then the estimated junction temperature It can be expressed as follows

[0141]

[0142] In the above formula, D is the output matrix.

[0143] D = [1 1 1 0 0 0]

[0144] The preferred embodiments of the present invention have been described in detail above. It should be understood that those skilled in the art can make numerous modifications and variations based on the concept of the present invention without creative effort. Therefore, all technical solutions that can be obtained by those skilled in the art based on the concept of the present invention through logical analysis, reasoning, or limited experimentation on the basis of existing technology should be within the scope of protection defined by the claims.

Claims

1. A method for estimating parameters of a motor controller, characterized in that, The method includes the following steps: Step 1: Calculate the power losses of the power components; Step 2: Collect the temperature of the U-phase and W-phase power components and calculate the losses. Based on the calculated power component losses, the collected U-phase and W-phase temperatures, and the cooling water temperature rise model, and using the model reference adaptive algorithm, realize the closed-loop temperature of the U-phase and W-phase temperature sensors estimated by the collected U-phase and W-phase temperature sensors and the cooling water temperature rise model, thereby estimating the cooling water flow rate. Step 3: Based on the collected temperatures of the power components in phases U, V, and W, the calculated losses, and the estimated cooling flow rate, estimate the cooling water temperatures for phases U, V, and W. Step 4: Estimate the junction temperature of the power components based on the collected power component temperatures, calculated losses, cooling water flow rate and temperature.

2. The parameter estimation method for a motor controller according to claim 1, characterized in that, The losses of the power components are calculated based on the bus voltage, phase current, duty cycle, and switching frequency. These losses include IGBT losses and diode losses. In the formula, For the losses of power components, For IGBT losses, This represents the diode's loss.

3. The parameter estimation method for a motor controller according to claim 2, characterized in that, The IGBT losses include: IGBT conduction losses and IGBT switching losses. In the formula, For IGBT losses, For the conduction loss of the IGBT, For the switching losses of IGBTs, This refers to the source-drain voltage of the IGBT. This is the instantaneous value of the phase current. Duty cycle, For switching frequency, Bus voltage , and For IGBT switching losses at 0, 1, and 2 cycles; The diode losses include: the diode's conduction losses and the diode's reverse recovery losses. In the formula, For diode losses, For diode conduction loss, This refers to the reverse recovery loss of the diode. For diode forward voltage drop, This is the instantaneous value of the phase current. Duty cycle, For switching frequency, Bus voltage , and These are the coefficients for diode switching losses at 0 cycles, 1 cycle, and 2 cycles, respectively.

4. The parameter estimation method for a motor controller according to claim 1, characterized in that, The mathematical expression for the cooling water temperature rise model is: In the formula, For the system's state variables, ; For the system output, ; For system input, , and They are respectively W Harmony U Phase acquisition temperature, matrix , , for: In the formula, , , , , , The parameters related to the flow direction of the cooling water are specifically the thermal resistance and heat capacity of each order in the third-order cooling water temperature rise thermal model. These parameters are related to the flow rate of the cooling water, and the parameter values ​​related to the flow direction of the cooling water for each flow rate are pre-calibrated.

5. The parameter estimation method for a motor controller according to claim 1, characterized in that, The step of estimating the cooling water temperature in step three includes: Based on the power component losses calculated in step one, the cooling water flow estimated in step two, the phase temperatures collected by the temperature sensors, and the thermal model of the temperature sensors, a model reference adaptive algorithm is used to realize the temperature difference between the temperature detected by the temperature sensors of each phase and the estimated water temperature of each phase, and the temperature difference between the estimated controller temperature of each phase and the estimated water temperature of each phase, thus estimating the cooling water temperature of each phase.

6. The parameter estimation method for a motor controller according to claim 5, characterized in that, The mathematical expression for the thermal model of the temperature sensor is: In the formula The state variables of the system are as follows: ; For the system output, ; For system input, ;matrix , , for: In the formula, , , These are the temperature state parameters of the third-order temperature sensor thermal model. The detected U-phase temperature; The detected U-phase cooling water temperature; For power component losses; , , , , , The thermal parameters related to the cooling water temperature are specifically the thermal resistance and thermal capacity of each order in the third-order temperature sensor thermal model. These parameters are related to the cooling water flow rate, and the thermal parameters related to the cooling water temperature corresponding to each flow rate are pre-calibrated.

7. The parameter estimation method for a motor controller according to claim 1, characterized in that, The step of estimating the junction temperature of the power components in step four includes: Based on the losses calculated in step one, the cooling water flow estimated in step two, the cooling water temperature of each phase estimated in step three, the temperature of each phase collected by the temperature sensor, and the junction temperature estimation thermal model, the temperature difference between the collected temperature of each phase controller and the estimated water temperature, and the temperature difference between the estimated temperature of each phase controller and the estimated water temperature are used to perform a temperature closed loop to estimate the junction temperature of each phase power component.

8. The parameter estimation method for a motor controller according to claim 7, characterized in that, The thermal model for estimating junction temperature is as follows: In the formula, For the system's state variables, ; For the system output, ; For system input, Matrix A, B, and C are respectively: In the above formula, , , These are the temperature state parameters for a third-order cooling water temperature rise model. , , These are the temperature state parameters of the third-order temperature sensor thermal model. The detected U-phase cooling water temperature; The detected U-phase temperature; For power component losses; , , , , , These are the parameters of the junction temperature-related thermal model, specifically the thermal resistance and heat capacity of each order in the third-order junction temperature estimation thermal model. , , , , , These are thermal parameters related to the cooling water temperature, specifically the thermal resistance and thermal capacity of each order in the third-order temperature sensor thermal model. The values ​​of these two thermal parameters are related to the cooling water flow rate, and the thermal parameter value corresponding to each flow rate is pre-calibrated.

9. The parameter estimation method for a motor controller according to claim 8, characterized in that, The mathematical model for estimating the junction temperature of each power component in a single-phase motor using the aforementioned observer is as follows: In the above formula, This is an estimate of the system state. ; For observing signals, ; For the estimated observed signal, ; The temperature of this phase detected by the temperature sensor. To estimate the cooling water temperature for this phase, A and B Here, L is the coefficient matrix, H is the observer matrix, and L is the observation matrix, respectively: In the above formula, , , The temperature state parameters of the estimated third-order cooling water temperature rise model; , , The temperature state parameters of the estimated third-order temperature sensor thermal model; This is the estimated temperature of the phase; This indicates the estimated cooling water temperature for that phase; , , , , , These are the observer parameters; Then the estimated junction temperature Represented as: In the above formula, D is the output matrix: 。

Images