Drive signal extraction and junction temperature estimation method, apparatus, and system

Abstract

The application provides a driving signal extraction and junction temperature estimation method, device and system based on a particle swarm algorithm. The signal extraction method comprises the following steps: obtaining external parameters of a grid-side voltage, a grid-side current and a DC-side voltage through a traction rectifier; calculating a stray inductance and a stray resistance of an external circuit through a particle swarm algorithm according to the grid-side voltage, the grid-side current and the DC-side voltage; substituting the stray inductance and the stray resistance into a grid-side closed loop to calculate a four-quadrant input voltage in combination with a Kirchhoff voltage law; and obtaining a driving signal of each IGBT module in the rectifier by analyzing a modulation strategy of the rectifier according to the four-quadrant input voltage.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of reliability evaluation of power electronic devices, and particularly relates to a driving signal extraction and junction temperature estimation method, device and system. BACKGROUND

[0002] With the continuous development of future high-speed trains, the train will face more variable working conditions and operating environments. The traction converter composed of Insulate-Gate Bipolar Transistor (IGBT) is in a long-term variable and harsh operating condition, and the reliability of the key component IGBT is greatly challenged. Relevant industry statistics show that IGBT failure accounts for more than 25% of the entire converter system failure and is currently considered to be the key factor affecting IGBT reliability. The high-power IGBT module used in trains belongs to a welding type package, and the internal connection is stacked by materials with different thermal expansion coefficients, which causes extrusion or stretching between different material layers when the module is subjected to temperature changes, resulting in shear stress and bending deformation, causing the bond wire to fall off and the solder layer to have voids, and ultimately leading to module failure. The IGBT junction temperature can be used to reflect the thermal stress of the chip and the overall module package, and is an effective parameter for evaluating the operating state of the device. The current junction temperature estimation method based on loss calculation and thermal network has been widely applied, but for the traction converter system, due to the limitation of the number of existing sensors on the train, only some external signals of the converter can be measured, and some key information for loss calculation, such as IGBT driving signal, cannot be directly obtained, so these methods are difficult to apply in the train converter. How to accurately estimate the junction temperature of the IGBT of the converter based on the existing sensor information of the train still needs a feasible method. SUMMARY

[0003] The present application aims to provide a driving signal extraction and junction temperature estimation method, device and system, which accurately extracts the IGBT driving signal by identifying the external parameters of the rectifier through the particle swarm algorithm, thereby solving the problem that the IGBT module driving signal and the junction temperature in the existing rectifier cannot be effectively obtained.

[0004] To achieve the above object, the driving signal extraction method provided by the application is suitable for a traction converter, and the method comprises the following steps: obtaining external parameters of a grid-side voltage, a grid-side current and a DC-side voltage through a traction rectifier; calculating a stray inductance and a stray resistance of an external circuit through a particle swarm algorithm according to the external parameters of the grid-side voltage, the grid-side current and the DC-side voltage; substituting the stray inductance and the stray resistance into a grid-side closed loop to calculate a four-quadrant input voltage in combination with a Kirchhoff voltage law; and obtaining a driving signal of each IGBT module in the rectifier by analyzing a modulation strategy of the converter according to the four-quadrant input voltage.

[0005] In the driving signal extraction method, optionally, the calculation of the stray inductance and the stray resistance of the external circuit through the particle swarm algorithm according to the external parameters of the grid-side voltage, the grid-side current and the DC-side voltage comprises the following steps: constructing an adaptive function according to the external parameters of the grid-side voltage, the grid-side current and the DC-side voltage; and obtaining an optimal estimated stray inductance and stray resistance by optimizing and calculating the adaptive function through the particle swarm algorithm.

[0006] In the driving signal extraction method, optionally, the optimization and calculation of the adaptive function through the particle swarm algorithm to obtain the optimal estimated stray inductance and stray resistance further comprises the following steps: updating an inertia coefficient in the particle swarm algorithm according to preset particle information and a preset coefficient; limiting a position and a speed of each particle in the particle algorithm according to the inertia coefficient; and obtaining the optimal estimated stray inductance and stray resistance by optimizing and calculating the particle algorithm after limiting the position and the speed.

[0007] In the driving signal extraction method, optionally, the substitution of the stray inductance and the stray resistance into the grid-side closed loop to calculate the four-quadrant input voltage in combination with the Kirchhoff voltage law comprises the following steps:

[0008] The four-quadrant input voltage is obtained through the following formula:

[0009] ;

[0010] In the formula, L is the stray inductance, R is the stray resistance, U ab is the four-quadrant input voltage, I s is the grid-side current.

[0011] In the driving signal extraction method, optionally, the driving signal of each IGBT module in the rectifier is obtained by analyzing the modulation strategy of the rectifier according to the four-quadrant input voltage, which comprises: obtaining the state of the current switching signal according to the four-quadrant input voltage, and obtaining the driving signal of each IGBT module in the rectifier according to the state of the current switching signal and the current direction by analyzing the modulation strategy of the rectifier.

[0012] The application also provides a junction temperature estimation method comprising the driving signal extraction method, which further comprises: obtaining the current flowing through the IGBT module and the voltage applied across the IGBT module according to the driving signal and the external voltage and current signals; obtaining the switching loss and the conduction loss generated by the IGBT module during operation according to the current and the voltage of the IGBT module; and obtaining the temperature estimation result of the IGBT module during operation by the IGBT heat transfer model according to the switching loss and the conduction loss.

[0013] In the junction temperature estimation method, optionally, the switching loss and the conduction loss generated by the IGBT module during operation are obtained according to the current and the voltage of the IGBT module, which comprises: the conduction loss is obtained by the following formula:

[0014]

[0015] In the above formula, E con is the conduction loss; E sw is the switching loss; V ce is the intersection of the tangent of the output characteristic curve corresponding to the conduction current and the x-axis; r is the slope of the tangent of the output characteristic curve corresponding to the conduction current; I c is the current flowing through the IGBT; T on is the conduction time of the IGBT this time.

[0016] In the junction temperature estimation method, optionally, the switching loss and the conduction loss generated by the IGBT module during operation are obtained according to the current and the voltage of the IGBT module, which comprises:

[0017] The switching loss is obtained by the following formula:

[0018]

[0019] In the above formula, E on i c E off i ​​​c ) corresponding current under rated conditions provided in the data sheet i c loss energy; U dc DC side voltage value at this time of conduction; K U , K Rg , K Ls , K Tj respectively represent the influence coefficient of DC side voltage, driving resistance, loop inductance, junction temperature on loss energy.

[0020] The application further provides a driving signal extraction device, which is suitable for a traction converter, and the device comprises an acquisition module, a calculation module, a voltage analysis module and an extraction module; the acquisition module is used to acquire external parameters of a grid side voltage, a grid side current and a DC side voltage through a traction converter; the calculation module is used to calculate a stray inductance and a stray resistance of an external circuit through a particle swarm algorithm according to the external parameters of the grid side voltage, the grid side current and the DC side voltage; the voltage analysis module is used to calculate a four-quadrant input voltage by substituting the stray inductance and the stray resistance into a grid side closed loop in combination with a Kirchhoff voltage law; and the extraction module is used to obtain a driving signal of each IGBT module in the traction converter by analyzing a modulation strategy of the traction converter according to the four-quadrant input voltage.

[0021] The application further provides a junction temperature estimation system comprising the driving signal extraction device, and the system further comprises an IGBT analysis module, a loss analysis module and an estimation module; the IGBT analysis module is used to obtain a current flowing through an IGBT module and a voltage applied to both ends according to the driving signal and external voltage and current signals; the loss analysis module is used to obtain switching loss and conduction loss generated by the IGBT module when in operation according to the current and the voltage of the IGBT module; and the estimation module is used to obtain a temperature estimation result of the IGBT module in operation through an IGBT heat transfer model according to the switching loss and the conduction loss.

[0022] The application further provides an electronic device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, and the processor implements the above method when executing the computer program.

[0023] The application further provides a computer readable storage medium, which stores a computer program for executing the above method.

[0024] The beneficial technical effect of the present application is that: through the application of the particle swarm algorithm in the traction rectifier, the acquisition of external stray inductance and stray resistance becomes easy, the value of the four-quadrant input voltage can be calculated more accurately, and thus the driving signal of the IGBT is obtained. Under the condition of only measurable external parameters of the rectifier, accurate estimation of the junction temperature of the IGBT module can be realized. Only the required voltage and current signals of the rectifier controller are needed to obtain the unmeasurable parameters, without additional sensor equipment, without changing the original control board, and without changing the structure of the rectifier. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings, which are included to provide a further understanding of the present application and constitute a part of this application, illustrate embodiments of the present application and together with the description serve to explain the present application. In the drawings:

[0026] Figure 1 A flowchart of a driving signal extraction method provided by an embodiment of the present application;

[0027] Figure 2 A flowchart of the acquisition of stray inductance and stray resistance provided by an embodiment of the present application;

[0028] Figure 3 A flowchart of the optimization of the particle algorithm provided by an embodiment of the present application;

[0029] Figure 4 A flowchart of a junction temperature estimation method provided by an embodiment of the present application;

[0030] Figure 5 A structural diagram of a driving signal extraction device provided by an embodiment of the present application;

[0031] Figure 6 A structural diagram of a junction temperature estimation system provided by an embodiment of the present application;

[0032] Figure 7 A rectifier topology diagram used by an embodiment of the present application;

[0033] Figure 8 A waveform diagram of the four-quadrant input voltage and the load voltage provided by an embodiment of the present application;

[0034] Figure 9 A diagram of the corresponding relationship between the modulation wave, the carrier wave and the switching signal provided by an embodiment of the present application;

[0035] Figure 10 A driving signal diagram of a single IGBT of the rectifier provided by an embodiment of the present application;

[0036] Figure 11A current waveform diagram of a single IGBT of a rectifier provided by an embodiment of the present application;

[0037] Figure 12 A voltage waveform diagram of a single IGBT of a rectifier provided by an embodiment of the present application;

[0038] Figure 13 A junction temperature fluctuation diagram of a single IGBT of a rectifier provided by an embodiment of the present application;

[0039] Figure 14 A structural diagram of an electronic device provided by an embodiment of the present application. DETAILED DESCRIPTION

[0040] The embodiments of the present application will be described in detail below with reference to the accompanying drawings and embodiments, so that how the present application applies technical means to solve technical problems and achieves technical effects can be fully understood and implemented. It should be noted that, unless there is a conflict, each embodiment in the present application and each feature in each embodiment can be combined with each other, and the technical solutions formed thereby are all within the protection scope of the present application.

[0041] In addition, the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a group of computer executable instructions, and although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown.

[0042] Please refer to Figure 1 As shown, the driving signal extraction method provided by the present application is suitable for a traction rectifier, and the method comprises:

[0043] S101 obtaining external parameters of a traction rectifier, including grid-side voltage, grid-side current and DC-side voltage;

[0044] S102 calculating the stray inductance and stray resistance of an external circuit according to the grid-side voltage, the grid-side current and the DC-side voltage by a particle swarm algorithm;

[0045] S103 substituting the stray inductance and the stray resistance into a grid-side closed loop to calculate a four-quadrant input voltage in combination with Kirchhoff's voltage law;

[0046] S104 obtaining the driving signal of each IGBT module in the rectifier by analyzing the modulation strategy of the rectifier according to the four-quadrant input voltage.

[0047] Therefore, in order to accurately obtain the drive signal and junction temperature of the IGBT module in the traction converter, and further provide necessary data support for loss calculation and thermal network, the application takes the traction converter as an example, and proposes a method for identifying external parameters of the converter based on a particle swarm algorithm, and then accurately extracting the IGBT drive signal.

[0048] The circuit topology of the simulation platform converter is shown in Figure 7 The main parameters of the converter are shown in Table 1, wherein the modulation mode is SPWM modulation.

[0049] Table 1

[0050]

[0051] Please refer to Figure 2 In an embodiment of the application, the stray inductance and stray resistance of the external circuit are calculated by a particle swarm algorithm according to the external parameters of the grid-side voltage, the grid-side current and the DC-side voltage, which include:

[0052] S201, constructing a fitness function according to the external parameters of the grid-side voltage, the grid-side current and the DC-side voltage;

[0053] S202, obtaining the optimal estimated stray inductance and stray resistance by optimizing and calculating the fitness function by a particle swarm algorithm.

[0054] Specifically, in actual work, the external parameters are mainly obtained from the converter, including the grid-side voltage U s , the grid-side current I s and the load voltage U dc The particle swarm algorithm is used to calculate the unmeasurable external parameters of stray inductance and stray resistance; the particle swarm algorithm has excellent optimization effect, and the position of each particle in the algorithm represents a candidate solution of the external parameter. The advantages and disadvantages of the position of each particle in the space are determined by the fitness function corresponding to the position of the particle. The position of each particle in the next generation is determined by its position in this generation and its own speed vector, and the speed determines the direction and distance of the flight of the particle. During the flight, the particle records the optimal position P reached by itself, and the group also updates the optimal position G reached by the group. The flight speed of the particle is determined by its current position, the optimal position reached by the particle itself, the optimal position reached by the group, and the speed of the particle at this time; thereafter, the particle swarm algorithm is used to accurately derive the stray inductance and stray resistance of the external circuit by establishing a LOSS function, and the specific process is as follows:

[0055] Firstly, the fitness function is determined according to the relationship between the grid-side voltage U s , the grid-side current I s , the load voltage U dc and the four-quadrant input voltage U ab . Since the four-quadrant input voltage U ab is also affected by external parameters when it is low, it will affect the establishment of the fitness function. The load voltage U dc is larger when the four-quadrant input voltage U ab is high, so here the voltage value 300V is taken as the reference, and only the case where the four-quadrant input voltage U ab is high is considered to establish the fitness function. Since the actual external stray inductance and stray resistance in the rectifier exist, the absolute value of the load voltage U dc is smallest when the absolute value of the four-quadrant input voltage U ab is high, as shown in FIG. 1, and if the calculated external stray inductance does not match the actual stray inductance value, it will lead to an increase in the difference between the above two, and by using this characteristic between the above parameters, the fitness function can be established as follows: Figure 8

[0056] ;

[0057] In the formula: U s is the grid-side voltage, I s is the grid-side current, U dc is the load voltage, L is the stray inductance of the external circuit, R is the stray resistance of the external circuit, le is the time length of external signal data acquisition, f ( L ) is the residual error, and when the residual error is minimized, the L corresponding to the residual error is the actual stray inductance of the external circuit.

[0058] Then, according to the fitness function, the particle swarm algorithm is used to optimize the fitness function, and when the fitness function reaches the minimum, the optimal estimated value of the stray inductance and stray resistance of the external circuit is obtained. Each particle in the algorithm has two attributes:

[0059] Position:​

[0060] ;

[0061] speed:

[0062] ;

[0063] ;

[0064] In the formula: v i,d t For the first t The speed of the next iteration v i,d t+1 For the first t The speed of +1 iteration, W The inertia coefficient, r 1, r 2 is a random number distributed in (0,1). C 1, C 2 represents the self-learning factor and the global learning factor, respectively. P i,d This represents the optimal position for a single particle. G i,d The optimal position for the group. x i,d t For the first t The position of the next iteration. v i,d t For the first t The speed of the next iteration, where the index i The particle's serial number. d Dimensions of the search space.

[0065] Please refer to Figure 3 As shown, in one embodiment of this application, obtaining the optimal estimated stray inductance and stray resistance by optimizing the fitness function using the particle swarm optimization algorithm further includes:

[0066] S301 updates the inertia coefficient in the particle swarm algorithm based on preset particle information and preset coefficients;

[0067] S302 limits the position and velocity of each particle in the particle algorithm according to the inertia coefficient;

[0068] S303 performs optimization calculations based on the particle algorithm after limiting position and velocity to obtain the optimal estimated stray inductance and stray resistance.

[0069] Specifically, since the parameters to be determined include external stray inductance and external stray resistance, when initializing the algorithm, it is only necessary to set the particle dimension to 2, and the settings of the other parameters are shown in Table 2.

[0070] Table 2

[0071]

[0072] In practical applications, to prevent the particle swarm optimization algorithm from getting trapped in local optima, the inertia coefficient is adjusted after initialization. W Update and limit the speed. v and location x The size, update, and limit methods are as follows:

[0073] ;

[0074] ;

[0075] ;

[0076] In the formula: T This represents the total number of iterations. v max This represents the maximum particle velocity. v min This represents the minimum particle velocity. x max The maximum value that limits the particle's position. x min This represents the minimum value constrained by the particle position. Subsequently, the particle swarm optimization algorithm calculates the stray inductance of the external circuit to be 5.1135 mH and the stray resistance to be 0.02049 Ω, which are essentially equal to the actual stray inductance and resistance values ​​of the external circuit, serving as the basis for the next step: four-quadrant input voltage. U ab The data provided support for the retrieval.

[0077] In one embodiment of this application, calculating the four-quadrant input voltage by substituting the stray inductance and stray resistance into the grid-side closed loop and combining it with Kirchhoff's voltage law includes obtaining the four-quadrant input voltage through the following formula:

[0078] ;

[0079] In the above formula, L is the stray inductance and R is the stray resistance. U ab For four-quadrant input voltage, I s This represents the grid-side current.

[0080] In actual work, Kirchhoff's voltage law, also known as Kirchhoff's second law, refers to the algebraic sum of potential differences (voltages) across all devices along a closed loop being equal to zero. That is, for any closed loop of the circuit, there is an expression as follows:

[0081] ;

[0082] In the embodiment, the grid-side circuit of the rectifier includes a grid-side voltage U s , a voltage caused by external stray inductance LdI s / dt , a voltage caused by external stray resistance RI s , and a four-quadrant input voltage U ab There are three voltage parameters in total, and according to Kirchhoff's voltage law, the expression is as follows:

[0083] ;

[0084] In an embodiment of the present application, the drive signal of each IGBT module in the rectifier is obtained by analyzing the modulation strategy of the rectifier according to the four-quadrant input voltage, including: obtaining the state of the current switching signal according to the four-quadrant input voltage, and obtaining the drive signal of each IGBT module in the rectifier according to the state of the current switching signal and the current current direction by analyzing the modulation strategy of the rectifier.

[0085] Specifically, in actual work, first, an ideal bridge arm switching function of the rectifier is established to describe the turn-on and turn-off process of the A bridge arm and the B bridge arm of the two-level pulse rectifier, and the traction winding resistance is ignored. The switching function S A and S B The state can be defined as:

[0086] ;

[0087] ;

[0088] Wherein, the upper bridge arm and the lower bridge arm of each bridge cannot be directly connected, and the switching signals of the upper bridge arm and the lower bridge arm are mutually reversed.

[0089] The rectifier is controlled by using the SPWM modulation strategy, and the generated sinusoidal modulation wave is compared with the triangular carrier wave. When the sinusoidal modulation wave is greater than the triangular carrier wave, the output is high, S A or S B 1; when the sinusoidal modulation wave is less than the triangular carrier wave, the output is zero SA or S B =0. Phase A modulated wave u a Modulated wave with phase B u b With a phase difference of 180°, the rectifier modulation signal can be expressed as:

[0090] ;

[0091] In the formula: m It is the ratio of the amplitude of the modulating signal to the amplitude of the carrier signal; ω The grid-side voltage angular frequency; u cm This represents the carrier amplitude.

[0092] The four-quadrant input voltage of the rectifier can be represented by the switching signal and the DC side voltage:

[0093] ;

[0094] In the formula: U ab For four-quadrant input voltage, U dc This is the DC side voltage of the rectifier.

[0095] because( S A - S B The value of ) has only three choices: 1, 0, and -1. U d Since it is a DC voltage, the four-quadrant input voltage U ab Values U dc , 0, - U dc The pulse signal. When the rectifier is operating normally, the output modulation signal is a sinusoidal signal with a fixed frequency and amplitude. By comparing it with a triangular carrier wave, the two bridge arms output PWM signals of a specific sequence. Within one cycle U ab The value will be S A and S B The value of varies according to a specific pattern. In this embodiment, the rectifier's fundamental frequency is 50Hz, and the PWM frequency is 350Hz. Taking one fundamental cycle as an example, the carrier wave and the two-phase modulation wave are as follows: Figure 9 As shown, in stage 1, the modulated wave is smaller than the carrier wave, S A S B The value is 00; in stage 2, the modulated wave of bridge A is greater than the carrier wave, and the modulated wave of bridge B is less than the carrier wave, SA S B The value is 10; similarly, the remaining stages S can be obtained. A S B Signal. Four-quadrant input voltage U ab The pulse train contains the drive signal of the rectifier IGBT module. By matching it with a specific pulse sequence, the state of the current switching signal is determined. Combined with the direction of the current, the drive signal of the rectifier IGBT module can be obtained, such as... Figure 10 As shown.

[0096] Please refer to Figure 4 As shown, in one embodiment of this application, a junction temperature estimation method including a drive signal extraction method is also provided, the method further comprising:

[0097] S401 obtains the current flowing through the IGBT module and the voltage applied across its terminals based on the drive signal and the external voltage and current signal;

[0098] S402 obtains the switching loss and conduction loss generated by the IGBT module during operation based on the current and voltage of the IGBT module.

[0099] S403 obtains the temperature estimation result of the IGBT module during operation based on the switching loss and the conduction loss through the IGBT heat transfer model.

[0100] The overall steps of the junction temperature estimation method are as follows: Step 1: Obtain external parameters such as grid-side voltage, grid-side current, and DC-side voltage from the traction rectifier; calculate the stray inductance and stray resistance of the external circuit according to the particle swarm optimization algorithm; Step 2: Substitute the values ​​of external stray inductance and stray resistance obtained in Step 1 into the grid-side closed loop, and calculate the four-quadrant input voltage using Kirchhoff's voltage law; Step 3: Using the four-quadrant input voltage and current obtained in Step 2, analyze the modulation strategy of the converter to obtain the drive signal of each IGBT module in the rectifier; Step 4: Based on the IGBT drive signal and external voltage and current signals obtained in Step 3, obtain the current flowing through the IGBT module and the voltage applied across its terminals; Step 5: Using the obtained voltage and current signals of the IGBT module, obtain the switching loss and conduction loss generated by the IGBT module during operation, and input them into the IGBT heat transfer model to obtain the temperature signal of the IGBT module during operation.

[0101] Specifically, since no additional sensors are installed, the current flowing through the IGBT module and the voltage applied across its terminals cannot be directly obtained. The IGBT voltage and current can only be obtained by controlling the required external electrical signals. The grid-side current flows into the IGBT module through the switching on and off of the switch, while the DC-side voltage directly acts on one of the bridge arms. Therefore, it is necessary to combine the IGBT drive signal to obtain the IGBT voltage and current. By applying the obtained IGBT module drive signal to the rectifier input current and the DC-side voltage, the current flowing through the IGBT module can be obtained, such as... Figure 11 As shown, the voltage applied to it, such as Figure 12 As shown. Subsequently, based on the IGBT module's drive signal and external voltage and current data, the process of obtaining the IGBT module's loss value and substituting it into the thermal network model to obtain the junction temperature mainly includes the following two formulas. The switching loss and conduction loss generated by the IGBT module during operation, based on the IGBT module's current and voltage, include: The conduction loss is calculated using the following formula:

[0102]

[0103] In the above formula, E con For conduction loss; E sw For switching losses; V ce The intersection of the tangent line of the output characteristic curve under the corresponding conduction current and the x-axis; r This refers to the slope of the tangent line to the output characteristic curve under the corresponding conduction current. I c The current flowing through the IGBT; T on This refers to the IGBT turn-on time.

[0104] The switching loss is calculated using the following formula:

[0105] ;

[0106] In the above formula, E on ( i c )and E off ( i c The current corresponding to the rated conditions provided in the datasheet. i c Energy loss; U dc This is the DC-side voltage value during this conduction; K U ,K Rg , K Ls , K Tj These represent the influence coefficients of DC-side voltage, drive resistance, loop inductance, and junction temperature on energy loss, respectively.

[0107] In practical applications, the average loss value of the IGBT within one fundamental frequency cycle is... P ave It can be represented as:

[0108] ;

[0109] In the formula: n The number of times the IGBT is turned on in one fundamental frequency cycle; E coni and E swi For the first i The energy loss value during the switching process; Ts is the fundamental frequency period.

[0110] Based on the principle of equal area, the periodic average loss... P ave Obtain the periodic half-sine loss P half :

[0111] ;

[0112] In the formula: ω =2π f 0 is the fundamental angular frequency. f 0 represents the fundamental frequency.

[0113] The obtained periodic half-sine loss P half Substituting these values ​​into the IGBT thermal network model used in this embodiment, the temperature change curve of the IGBT can be obtained, as shown below. Figure 13 As shown.

[0114] Therefore, it can be seen that the junction temperature calculation method proposed in this application can acquire the traction rectifier drive signal without installing additional sensors or modifying the control board, based on the particle swarm optimization algorithm. Furthermore, the junction temperature estimation is performed based on the fundamental period and takes into account the parameter changes of the adaptive inductor, thus solving the problem that the junction temperature of the IGBT module in existing rectifiers cannot be accurately obtained.

[0115] It is worth mentioning that the main error of the junction temperature calculation method of the present application comes from the precision of the Foster thermal network in the data hand, the higher the order of the selected thermal network, the more accurate the junction temperature calculation result of the present application, but the running time will also be longer. Therefore, it is crucial to balance the relationship between calculation accuracy and operation speed.

[0116] Referring to Figure 5 The present application also provides a driving signal extraction device suitable for a traction converter, which comprises a collection module, a calculation module, a voltage analysis module and an extraction module; the collection module is used to obtain external parameter grid-side voltage, grid-side current and DC-side voltage through the traction rectifier; the calculation module is used to calculate the stray inductance and stray resistance of the external circuit through the particle swarm algorithm according to the external parameter grid-side voltage, the grid-side current and the DC-side voltage; the voltage analysis module is used to calculate the four-quadrant input voltage by substituting the stray inductance and the stray resistance into the grid-side closed loop combined with the Kirchhoff voltage law; and the extraction module is used to obtain the driving signal of each IGBT module in the rectifier by analyzing the modulation strategy of the converter according to the four-quadrant input voltage.

[0117] Further, referring to Figure 6 The present application also provides a junction temperature estimation system comprising the driving signal extraction device, which further comprises an IGBT analysis module, a loss analysis module and an estimation module; the IGBT analysis module is used to obtain the current flowing through the IGBT module and the voltage applied across the two ends according to the driving signal and the external voltage and current signals; the loss analysis module is used to obtain the switching loss and conduction loss generated by the IGBT module during operation according to the current and voltage of the IGBT module; and the estimation module is used to obtain the temperature estimation result of the IGBT module in operation through the IGBT heat transfer model according to the switching loss and the conduction loss.

[0118] The present application has the beneficial technical effects that: through the application of the particle swarm algorithm in the traction rectifier, the acquisition of the external stray inductance and stray resistance becomes easy, the value of the four-quadrant input voltage can be calculated more accurately, and thus the driving signal of the IGBT is obtained. Under the condition of only measurable external parameters of the rectifier, accurate estimation of the junction temperature of the IGBT module can be realized. By only using the voltage and current signals required by the rectifier control, the unmeasurable parameters can be obtained without additional installation of sensor equipment, without changing the original control board card and without changing the structure of the rectifier.

[0119] The present application also provides an electronic device comprising a memory, a processor and a computer program stored on the memory and executable on the processor, wherein the processor implements the above-mentioned method when executing the computer program.

[0120] The present application also provides a computer readable storage medium storing a computer program for executing the above method.

[0121] As shown in FIG. 6, the electronic device 600 can further include a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is to be noted that the electronic device 600 does not necessarily include all the components shown in FIG. 6; in addition, the electronic device 600 can include components not shown in FIG. 6, which can be referred to the prior art. Figure 14 Figure 14 As shown in FIG. 6, the electronic device 600 can further include a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is to be noted that the electronic device 600 does not necessarily include all the components shown in FIG. 6; in addition, the electronic device 600 can include components not shown in FIG. 6, which can be referred to the prior art. Figure 14

[0122] As shown in FIG. 6, the electronic device 600 can further include a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is to be noted that the electronic device 600 does not necessarily include all the components shown in FIG. 6; in addition, the electronic device 600 can include components not shown in FIG. 6, which can be referred to the prior art. Figure 14 As shown in FIG. 6, the electronic device 600 can further include a communication module 110, an input unit 120, an audio processing unit 130, a display 160, and a power supply 170. It is to be noted that the electronic device 600 does not necessarily include all the components shown in FIG. 6; in addition, the electronic device 600 can include components not shown in FIG. 6, which can be referred to the prior art.

[0123] The memory 140, for example, can be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, or other suitable device. Information relating to failures can be stored, in addition to programs for executing the information. The central processing unit 100 can execute the programs stored in the memory 140 to achieve information storage or processing, etc.

[0124] The input unit 120 provides input to the central processing unit 100. The input unit 120 is, for example, a key or a touch input device. The power supply 170 is used to supply power to the electronic device 600. The display 160 is used to display display objects such as images and text. The display can be, for example, an LCD display, but is not limited thereto.

[0125] The memory 140 can be a solid state memory, such as a read only memory (ROM), a random access memory (RAM), a SIM card, etc. It can also be a memory that saves information even when power is off, can be selectively erased, and is provided with more data, examples of which are sometimes referred to as EPROM, etc. The memory 140 can also be some other type of device. The memory 140 includes a buffer memory 141 (sometimes referred to as a buffer). The memory 140 can include an application / function storage section 142 for storing application programs and function programs or for executing the flow of the operation of the electronic device 600 by the central processing unit 100.

[0126] ​​The memory 140 can further include a data storage 143 for storing data such as contacts, digital data, pictures, sounds, and / or any other data used by the electronic device. A driver storage 144 of the memory 140 can include various drivers of the electronic device for a communication function and / or for performing other functions of the electronic device (e.g., a messaging application, a phonebook application, etc.).

[0127] The communication module 110 is a transmitter / receiver 110 that transmits and receives signals via the antenna 111. The communication module (transmitter / receiver) 110 is coupled to the central processor 100 to provide input signals and receive output signals, as in the case of a conventional mobile communication terminal.

[0128] Based on different communication technologies, a plurality of communication modules 110, such as a cellular network module, a Bluetooth module, and / or a wireless LAN module, etc., can be provided in the same electronic device. The communication module (transmitter / receiver) 110 is further coupled to the speaker 131 and the microphone 132 via the audio processor 130 to provide audio output via the speaker 131 and receive audio input from the microphone 132, thereby implementing a general telecommunication function. The audio processor 130 can include any suitable buffer, decoder, amplifier, etc. In addition, the audio processor 130 is coupled to the central processor 100, thereby enabling recording on the local device through the microphone 132 and enabling playing of a sound stored on the local device through the speaker 131.

[0129] Those skilled in the art will appreciate that embodiments of the present application can be readily used as a method, a system or a computer program product. Accordingly, the present application can take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application can take the form of a computer program product on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROMs, optical storage devices, etc.) embodying computer readable program code thereon.

[0130] The present application is described with reference to the flowchart illustrations and / or block diagrams of the methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each block of the flowchart illustrations and / or block diagrams, and combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general purpose computer, special purpose computer, embedded processing device or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions of the flowchart illustrations and / or block diagrams specified in the flowchart illustrations and / or block diagrams. These computer program instructions can also be stored in a computer-usable or computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-usable or computer-readable memory produce an article of manufacture including instructions which implement the function specified in the flowchart illustrations and / or block diagrams. Figure 1 one or more functions Figure 1means for performing the function specified by the block or blocks.

[0131] These computer program instructions can also be stored in a computer readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer readable memory produce an article of manufacture including instructions which implement the flow Figure 1 flow or flows and / or blocks Figure 1 means for performing the function specified by the block or blocks.

[0132] These computer program instructions can also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the flow Figure 1 flow or flows and / or blocks Figure 1 means for performing the function specified by the block or blocks.

[0133] The above detailed description has been described for purposes of clarity and understanding only. It is not intended to limit the scope of the application beyond the limitations provided in the appended claims. Numerous specific details have been set forth in the above description in order to provide a thorough and complete understanding of the application. Therefore, it will be appreciated that there are many alternative ways that the above-described application might be implemented. It is intended that the scope of the application be defined by the appended claims and their equivalents.

Claims

1. A method for extracting drive signals, applicable to traction converters, characterized in that, The method includes: External parameters such as grid-side voltage, grid-side current, and DC-side voltage are obtained through a traction rectifier. The stray inductance and stray resistance of the external circuit are calculated using the particle swarm optimization algorithm based on the external parameters: grid-side voltage, grid-side current, and DC-side voltage. Substitute the stray inductance and stray resistance into the grid-side closed loop and combine Kirchhoff's voltage law to calculate the four-quadrant input voltage; The drive signal for each IGBT module in the converter is obtained by analyzing the modulation strategy of the converter based on the four-quadrant input voltage.

2. The driving signal extraction method according to claim 1, characterized in that, The stray inductance and stray resistance of the external circuit are calculated using a particle swarm optimization algorithm based on the external parameters: grid-side voltage, grid-side current, and DC-side voltage. A fitness function is constructed based on the external parameters: grid-side voltage, grid-side current, and DC-side voltage. The optimal estimated stray inductance and stray resistance are obtained by optimizing the fitness function using the particle swarm optimization algorithm.

3. The driving signal extraction method according to claim 2, characterized in that, The optimal estimates of stray inductance and stray resistance obtained by optimizing the fitness function using the particle swarm optimization algorithm also include: The inertia coefficient in the particle swarm algorithm is updated based on preset particle information and preset coefficients; The position and velocity of each particle in the particle swarm optimization algorithm are constrained according to the inertia coefficient. The optimal estimates of stray inductance and stray resistance are obtained by performing optimization calculations based on the particle swarm optimization algorithm with constraints on position and velocity.

4. The driving signal extraction method according to claim 1, characterized in that, Substituting the stray inductance and stray resistance into the grid-side closed loop and applying Kirchhoff's voltage law, the four-quadrant input voltage is calculated to include: The four-quadrant input voltage is obtained using the following formula: ； In the above formula, U s Where L is the grid-side voltage, L is the stray inductance, and R is the stray resistance. U ab For four-quadrant input voltage, I s This represents the grid-side current.

5. The driving signal extraction method according to claim 1, characterized in that, Based on the four-quadrant input voltage, the driving signal for each IGBT module in the converter is obtained by analyzing the modulation strategy of the converter, including: The state of the current switching signal is obtained based on the four-quadrant input voltage. The drive signal of each IGBT module in the converter is obtained through the modulation strategy of the converter based on the state of the current switching signal and the current current direction.

6. A junction temperature estimation method incorporating the driving signal extraction method of claim 1, characterized in that, The method further includes: The current flowing through the IGBT module and the voltage applied across its terminals are obtained based on the drive signal and external parameters, grid-side voltage and grid-side current signals. The switching loss and conduction loss generated by the IGBT module during operation are obtained based on the current and voltage of the IGBT module. The junction temperature of the IGBT module during operation is estimated using the IGBT heat transfer model based on the switching loss and the conduction loss.

7. The junction temperature estimation method according to claim 6, characterized in that, The switching losses and conduction losses generated by the IGBT module during operation are obtained based on the current and voltage of the IGBT module, including: The conduction loss is calculated using the following formula: In the above formula, E con For conduction loss; V ce The intersection of the tangent line of the output characteristic curve under the corresponding conduction current and the x-axis; r This refers to the slope of the tangent line to the output characteristic curve under the corresponding conduction current. I c The current flowing through the IGBT; T on This refers to the IGBT turn-on time.

8. The junction temperature estimation method according to claim 6, characterized in that, The switching losses and conduction losses generated by the IGBT module during operation are obtained based on the current and voltage of the IGBT module, including: The switching loss is calculated using the following formula: In the above formula, E sw For switching losses; E on ( i c )and E off ( i c The current corresponding to the rated conditions provided in the datasheet. i c Energy loss during the opening and closing processes; U dc This is the DC-side voltage value during this conduction; K U , K Rg , K Ls , K Tj These represent the influence coefficients of DC-side voltage, drive resistance, loop inductance, and junction temperature on energy loss, respectively. U N This is the voltage reference value for measuring switching losses in the datasheet.

9. A drive signal extraction device, suitable for traction converters, characterized in that, The device includes: an acquisition module, a calculation module, a voltage analysis module, and an extraction module; The acquisition module is used to obtain external parameters such as grid-side voltage, grid-side current, and DC-side voltage through the traction rectifier. The calculation module is used to calculate the stray inductance and stray resistance of the external circuit based on the external parameters grid-side voltage, grid-side current and DC-side voltage using a particle swarm optimization algorithm. The voltage analysis module is used to substitute the stray inductance and stray resistance into the grid-side closed loop and calculate the four-quadrant input voltage using Kirchhoff's voltage law; The extraction module is used to obtain the drive signal of each IGBT module in the converter by analyzing the modulation strategy of the converter based on the four-quadrant input voltage.

10. A junction temperature estimation system comprising the drive signal extraction device of claim 9, characterized in that, The system also includes: an IGBT analysis module, a loss analysis module, and an estimation module; The IGBT analysis module is used to obtain the current flowing through the IGBT module and the voltage applied at both ends based on the drive signal and external parameters such as grid-side voltage and grid-side current signal. The loss analysis module is used to obtain the switching loss and conduction loss generated by the IGBT module during operation based on the current and voltage of the IGBT module. The estimation module is used to obtain the temperature estimation result of the IGBT module during operation based on the switching loss and the conduction loss through the IGBT heat transfer model.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the computer program, it implements the method of any one of claims 1 to 8.

12. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that enables a computer to execute the method of any one of claims 1 to 8.

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