CN105631083A - Method for establishing high-voltage IGBT module switch transient model suitable for circuit simulation - Google Patents

Abstract

The invention provides a method for establishing a high-voltage IGBT module switch transient model suitable for circuit simulation. The modeling method includes a high-voltage IGBT switch transient model and an anti-parallel diode reverse recovery model establishment method. Based on methods such as mechanism derivation, electrical equivalence, device manual data analysis, and mathematical fitting, the present invention uses circuit components such as voltage-controlled current sources, variable capacitors, and custom programming module algorithms to be used on circuit simulation platforms such as PSCAD, SIMULINK, and SABER. Modeling. Compared with the prior art, the high-voltage IGBT module switch transient model suitable for circuit simulation provided by the present invention can not only realize various operating states of the IGBT module in the circuit simulation, but also simulate the high-voltage IGBT at a nanosecond-level simulation step Switching transient characteristics such as voltage and current spikes, tail current, Miller platform, and diode reverse recovery of the module. Therefore, the present invention has a certain role in promoting the study of the loss analysis and control and protection strategies of the high-voltage IGBT module in the field of flexible direct current transmission.

Description

A Method for Establishing Transient Model of High-Voltage IGBT Module Switching Suitable for Circuit Simulation

technical field

The invention relates to the field of power electronics technology simulation, in particular to a method for establishing a high-voltage IGBT module switch transient model suitable for circuit simulation.

Background technique

Insulated gate bipolar transistors combine the dual advantages of power MOSFETs and bipolar devices, and have the characteristics of high input impedance, high voltage resistance, large current capacity, and fast switching speed, and have received more and more attention and research. In the current field of power electronics technology, high-voltage IGBTs and diodes constitute switching modules that have been widely used in various voltage source power electronic conversion devices, such as voltage source converter type direct current transmission (VSC-HVDC), static var compensator ( STATCON) and so on, it is more and more important for the research and modeling of its switching transient process. Therefore, establishing an accurate and practical IGBT module switching transient model has important guiding significance for the safe and reliable operation of the converter and the optimization of electrical performance.

At present, in the modeling research of power electronic devices, there are mainly two types of mechanism models and behavior models. The mechanism model is to use the knowledge of semiconductor physics to simplify the electrical behavior of carriers to obtain analytical expressions and then solve the physical equations. Its typical representatives are: Hefner model, KuangSheng model and Kraus model. It is very difficult for users who lack the knowledge of device physics to obtain the parameters of the mechanism model, and the model contains complex semiconductor physics equations, which requires a large amount of calculation, long simulation time, and problems such as calculation convergence. The behavioral model is faster than the simulation speed, but only considers the external characteristics of the device, the physical concept is not clear, the parameters are not easy to adjust, and the model's versatility is relatively poor.

Therefore, using methods such as mechanism derivation, electrical equivalence, and curve fitting, comprehensively considering the model accuracy and simulation speed, as well as the interaction between the transient characteristics of the IGBT and the reverse recovery characteristics of the diode, to avoid solving complex semiconductor physical equations, based on the device According to the manual data, it is particularly important to establish a high-voltage IGBT module switching transient model suitable for circuit simulation that can simulate switching transient characteristics such as high-voltage IGBT module voltage and current spikes, tail current, Miller platform, and diode reverse recovery.

Contents of the invention

In order to meet the needs of the prior art and aim at the shortcomings of the mechanism model and behavior model described in the background art, the present invention proposes a method for establishing a high-voltage IGBT module switching transient model suitable for circuit simulation.

A method for establishing a high-voltage IGBT module switch transient model suitable for circuit simulation, characterized in that: the method includes the following steps:

Step 1: Establish a high-voltage IGBT transient equivalent model;

Step 2: Establish the reverse recovery model of the anti-parallel diode;

Step 3: According to the IGBT transient model and diode reverse recovery model obtained in Step 1 and Step 2, connect the two according to the circuit structure of the high-voltage IGBT module, modify and add corresponding parameters and modules, so as to establish a high-voltage circuit suitable for circuit simulation IGBT module switching transient model.

In step 1, the high-voltage IGBT transient equivalent model includes a MOSFET-BJT equivalent module, a trailing current equivalent module, and a parasitic capacitance equivalent module. Specifically, the above three equivalent modules are modeled as follows:

(1) MOSFET-BJT equivalent module:

When the IGBT is turned on, there are two internal current paths: 1) The current path In generated by the flow of electrons corresponds to the MOSFET structure. 2) The current path Ip generated by hole flow corresponds to the BJT structure.

When the IGBT works in different states, the expression of the current flowing through the MOSFET is:

(1)

Using electrical equivalent simplification, based on circuit simulation requirements, the following relationship can be approximated according to the characteristics of BJT:

(2)

Therefore, the MOSFET-BJT equivalent module can use a voltage-controlled current source to simulate the on-state current Ic of the IGBT module, and its analytical expression is as follows:

(3)

Among them, the equivalent transconductance K=(1+β)K _p ; V _ge is the gate-emitter voltage; V _T is the IGBT turn-on threshold voltage; V _ce is the IGBT collector-emitter voltage; K _p is the MOSFET transconductance; is the BJT current gain; I _mos is the current flowing through the MOSFET; I _c is the collector current flowing through the IGBT current;

(2) Tailing current equivalent module:

During the turn-off transient process of the IGBT, due to the existence of BJT in the IGBT, it takes time for a large number of excess carriers in the base region to recombine, which makes the turn-off current have a longer tail time.

(4)

Among them, τ is the minority carrier lifetime, that is, the tailing time constant; t ₀ is the starting time of the tailing current; during the turn-off process, when V _ge is less than the threshold voltage, the tailing starts, and the collector current is the starting current of the tailing at this time I _tail0 . Add the formula (4) to the formula (3) to obtain a complete MOSFET-BJT equivalent module.

(3) Parasitic capacitance equivalent module:

In the data sheet, input capacitance C _ies , output capacitance C _oes and feedback capacitance C _res are parameters commonly used in applications. Their relationship with the interelectrode capacitance is as follows:

(5)

Using the formula (5) combined with the data in the device manual, the corresponding inter-electrode parasitic capacitance value is obtained, so as to complete the parasitic capacitance equivalent module.

In step 2, the anti-parallel diode reverse recovery model adopts the idea of a macro model, combined with the diode reverse recovery characteristics, and based on the device data sheet, the corresponding equivalent model is established. The relevant parameters of the model are shown in formula (6).

(6)

Among them, τ _re is the reverse recovery decay time constant; R and L are free quantities, according to the circuit simulation requirements and actual device conditions, it is desirable to take L=100nH, then R can take the corresponding value according to formula (6); I _rm is the inverse dI _f /dt is the reverse recovery current slope; t _rr is the reverse recovery time; Q _rr is the reverse recovery charge, and K _re is the reverse recovery proportional coefficient.

In step 3, the two equivalent models in steps 1 and 2 are connected according to the circuit structure of the high-voltage IGBT module, and a complete switching transient model circuit of the high-voltage IGBT module is composed of the circuit structure module and the custom control parameter module.

The circuit structure module of the high-voltage IGBT module is characterized in that the packaged IGBT circuit structure module leads out to the outside three electrodes G, C, and E to connect with the main circuit, and its internal structure consists of parasitic capacitance between electrodes, stray resistance inductance, gate It is composed of pole internal resistance, MOSFET-BJT equivalent voltage-controlled current source and diode reverse recovery equivalent circuit.

Use the software module to collect the corresponding voltage and current values and input them to the model custom parameter module, and at the same time accept the output of the custom parameter module as the control source of the voltage-controlled current source, and introduce the driving voltage signal from the gate G to realize the control of the IGBT working status and each pole Control of voltage and current. The circuit structure module closely corresponds to the static and dynamic characteristics of the IGBT.

The self-defined parameter module is characterized in that it mainly includes a parasitic capacitance parameter module, a MOSFET-BJT equivalent current source module and a diode reverse recovery equivalent current source module. The module accepts parameters related to the circuit structure module and the switch transient model, and according to the modeling method, customizes the programming module and outputs corresponding parameters to the circuit structure module.

Compared with the closest prior art, the excellent effect of the present invention is:

1. For the application of high-voltage IGBT modules, based on the existing model research, using methods such as mechanism derivation, electrical equivalence, and curve fitting, and comprehensively considering model accuracy and simulation speed, a high-voltage IGBT module suitable for circuit simulation is proposed A method for establishing a transient model of a switch.

2. The present invention is deduced from the mechanism, the physical concept is clear, and the transient characteristics of the IGBT and the reverse recovery characteristics of the diode are comprehensively considered. The results are true and reliable; complex physical equations are avoided, and the parameters are significantly reduced and easy to extract. The data sheet can be determined; the model parameters are easy to adjust, and are suitable for different IGBT and high-voltage applications.

3. The present invention can not only realize various operating states of the IGBT module in circuit simulation, but also simulate the voltage and current peaks, trailing current, Miller platform, diode reverse recovery and other switches of the high-voltage IGBT module under the simulation step size of nanoseconds transient characteristics.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings.

Fig. 1 is: a kind of high-voltage IGBT module switch transient model circuit diagram that is suitable for circuit simulation provided by the present invention;

Figure 2 is: (a) MOSFET-BJT equivalent module, (b) diode reverse equivalent module, (c) inter-electrode parasitic capacitance equivalent module implementation circuit diagram under the PSCAD/EMTDC platform in the embodiment of the present invention;

Fig. 3 is: the resistance-inductive load IGBT module test circuit of the diode clamp used for testing and verifying the correctness of the model in the embodiment of the present invention;

Fig. 4 is: in the embodiment of the present invention, the test circuit emulation waveform contrast diagram that builds under the test circuit of PSCAD/EMTDC platform and SABER emulation software;

Fig. 5 is a comparison diagram of the simulated waveform of the test circuit built under the PSCAD/EMTDC platform in the embodiment of the present invention and the experimentally measured data.

detailed description

The technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application. It should be emphasized that the following descriptions are only exemplary and not intended to limit the scope of the present invention and its application. .

The invention provides a method for establishing a transient state model of a high-voltage IGBT module switch suitable for circuit simulation.

Fig. 1 is a circuit diagram of a high-voltage IGBT module switching transient model suitable for circuit simulation provided by the present invention. In Figure 1, the high-voltage IGBT module is composed of a circuit structure module and a user-defined parameter module.

The encapsulated IGBT circuit structure module externally leads three electrodes G, C, and E to connect with the main circuit. Its internal structure consists of parasitic capacitance between electrodes, stray resistance inductance, gate internal resistance, MOSFET-BJT equivalent voltage control current source and diode reverse recovery equivalent circuit. Use the software module to collect the corresponding voltage and current values and input them to the model custom parameter module, and at the same time accept the output of the custom parameter module as the control source of the voltage-controlled current source, and introduce the driving voltage signal from the gate G to realize the control of the IGBT working status and each pole Control of voltage and current. The circuit structure module closely corresponds to the static and dynamic characteristics of the IGBT.

Figure 2 is a custom parameter module, which mainly includes a MOSFET-BJT equivalent current source module, a diode reverse recovery current source equivalent module, and a parasitic capacitance parameter module. The self-defining parameter module accepts the relevant parameters of the circuit structure module and the switch transient model, and according to the modeling method, customizes the programming module and outputs corresponding parameters to the circuit structure module.

Figure 2(a) is a MOSFET-BJT equivalent current source module, where the module inputs are the conduction threshold voltage V _T , the gate-emitter voltage V _ge , the collector-emitter voltage V _ce , the collector current I _c , the simulation time t and Related control parameters, etc., and the output is the current value I _mos1 of the MOSFET-BJT equivalent voltage-controlled current source. Through the internal self-defined programming according to the content of step 1, the characteristics of MOSFET and BJT are simulated.

Figure 2(b) is the equivalent module of diode reverse recovery current source, where the input of the module is diode current I _d , simulation time t, reverse recovery current peak value I _rm , reverse recovery current slope dif and other reverse recovery parameters, and The output is the current value I _f of the diode reverse recovery equivalent current source. Through internal self-defined programming according to the content of step 2, the reverse recovery characteristics of the simulated diode are simulated.

Figure 2(c) shows the inter-electrode parasitic capacitance module, where the module input is the collector-emitter voltage V _ce and the simulation time t, and the module output is the input capacitance C _ies , the output capacitance C _oes , and the feedback capacitance C _res . It is realized through custom programming of the capacitance characteristic curve in the device manual, and then converted into inter-electrode parasitic capacitances C _ge , C _gc and C _ce according to step 3.

Figure 3 uses a diode-clamped resistive-inductive load circuit as a high-voltage IGBT module switch transient model test circuit. Among them, the freewheeling diode is replaced by an IGBT module, R _G is 6Ω for the gate external resistance, LL is 50uH for the inductive load, RL is 2.2Ω for the load resistance, and the external voltage V _cc is 1kV.

Table 1 Key parameters of IGBT module switching transient model parameter value parameter value Rg/Ω 3.2 R/Ω 0.65 Ls/nH 20 L/nH 100 Rs/mΩ 0.3 _Rf /mΩ 11.8 K /A·V ^-2 35.4 I _rm /A 113 τ/μs 5 τ _re /μs 0.065

Table 1 shows the key parameters of the IGBT module switching transient model, taking the CM450DXL-34SA 1.7kV/450A-IGBT power module produced by Mitsubishi Corporation as an example.

The two gate drive signals U _g1 and U _g2 respectively control the working states of the IGBT1 module and the IGBT2 module by outputting +15V and 0V. In the test circuit, U _g1 is constant at 0V, that is, IGBT1 remains off and only plays the role of a freewheeling diode. By controlling the U _g2 output voltage +15V and 0V, turn on the IGBT2 module first, charge the load inductance LL, increase the circuit current to 450A, and then turn off the IGBT2 module to obtain the turn-off current and voltage transient waveform of the IGBT2 module. The load inductance passes through IGBT1 The diode in the module continues to flow, and then the IGBT2 module is turned on to obtain the corresponding turn-on voltage and current transient waveforms to test the model's steady-state and transient characteristics. The comparison results of the simulation waveforms of PSCAD and SABER are shown in Figure 4.

In order to further verify the correctness of the model, the model of the IGBT is SGH40N60, and the model of the freewheeling diode is HFA25TB60. According to the corresponding model device manual, the relevant simulation parameters are extracted and modified. The comparison results of the simulation waveform and the experimental data are shown in Figure 5.

By comparing the PSCAD simulation waveform with the SABER simulation waveform and the experimental measured data, the high-voltage IGBT module switching transient model suitable for circuit simulation proposed by the present invention can not only experiment various working states of the high-voltage IGBT, but also simulate current and voltage spikes, Miller Platform, tail current, diode reverse recovery current and other switching transient characteristics.

Finally, it should be noted that the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of this application.

Claims (7)

1. A method for establishing a high-voltage IGBT module switch transient model suitable for circuit simulation, characterized in that: the method may further comprise the steps: Step 1: Establish a high-voltage IGBT transient equivalent model; Step 2: Establish the reverse recovery model of the anti-parallel diode; Step 3: According to the IGBT transient model and diode reverse recovery model obtained in Step 1 and Step 2, connect the two according to the circuit structure of the high-voltage IGBT module, modify and add corresponding parameters and modules, so as to establish a high-voltage circuit suitable for circuit simulation IGBT module switching transient model. 2. a kind of high-voltage IGBT module switching transient model establishment method suitable for circuit simulation as claimed in claim 1, is characterized in that, in described step 1, high-voltage IGBT transient equivalent model comprises MOSFET-BJT equivalent module, Tailing current equivalent module and parasitic capacitance equivalent module, the specific modeling of the above three equivalent modules is as follows: (1) MOSFET-BJT equivalent module: When the IGBT is turned on, there are two current paths inside: 1) The current path In generated by the flow of electrons corresponds to the MOSFET structure; 2) The current path Ip generated by the hole flow corresponds to the BJT structure; When the IGBT works in different states, the expression of the current flowing through the MOSFET is: (1) Using electrical equivalent simplification, based on circuit simulation requirements, the following relationship can be approximated according to the characteristics of BJT: (2) Therefore, the MOSFET-BJT equivalent module can use a voltage-controlled current source to simulate the on-state current Ic of the IGBT module, and its analytical expression is as follows: (3) Among them, the equivalent transconductance K=(1+β)K _p ; V _ge is the gate-emitter voltage; V _T is the IGBT turn-on threshold voltage; V _ce is the IGBT collector-emitter voltage; K _p is the MOSFET transconductance; is the BJT current gain; I _mos is the current flowing through the MOSFET; I _c is the collector current flowing through the IGBT current; (2) Tailing current equivalent module: During the IGBT turn-off transient process, due to the existence of BJT in the IGBT, it takes time for a large number of excess carriers in the base area to recombine, so that the turn-off current will have a longer tail time; (4) Among them, τ is the minority carrier lifetime, that is, the tailing time constant; t ₀ is the starting time of the tailing current; during the turn-off process, when V _ge is less than the threshold voltage, the tailing starts, and the collector current is the starting current of the tailing at this time I _tail0 ; Add the formula (4) to the formula (3) to obtain a complete MOSFET-BJT equivalent module; (3) Parasitic capacitance equivalent module: In the data sheet, input capacitance C _ies , output capacitance C _oes and feedback capacitance C _res are commonly used parameters in applications; Their relationship with the interelectrode capacitance is as follows: (5) Using the formula (5) combined with the data in the device manual, the corresponding inter-electrode parasitic capacitance value is obtained, so as to complete the parasitic capacitance equivalent module. 3. A kind of high-voltage IGBT module switching transient model establishment method suitable for circuit simulation as claimed in claim 1, it is characterized in that, in described step 2, antiparallel diode reverse recovery model adopts the thinking of macro model, in conjunction with diode Reverse recovery characteristics, based on the device data sheet, establish a corresponding equivalent model; The relevant parameters of the model are shown in formula (6); (6) Among them, τ _re is the reverse recovery decay time constant; R and L are free quantities, according to the circuit simulation requirements and actual device conditions, it is desirable to take L=100nH, then R can take the corresponding value according to formula (6); I _rm is the inverse dI _f /dt is the reverse recovery current slope; t _rr is the reverse recovery time; Q _rr is the reverse recovery charge, and K _re is the reverse recovery proportional coefficient. 4. a kind of high-voltage IGBT module switching transient model establishment method suitable for circuit simulation as claimed in claim 1, is characterized in that, in described step 3, two equivalent models in described step 1 and 2, according to The circuit structure connection of the high voltage IGBT module is composed of the circuit structure module and the control parameter definition module to form a complete high voltage IGBT module switching transient model circuit. 5. The circuit structure module of the high voltage IGBT module as claimed in claim 4, characterized in that, the encapsulated IGBT circuit structure module externally draws three electrodes G, C, and E to connect with the main circuit, and its internal structure is formed by parasitic electrodes between the poles. Capacitance, stray resistance inductance, gate internal resistance, MOSFET-BJT equivalent voltage-controlled current source and diode reverse recovery equivalent circuit. 6. high voltage IGBT module switch transient model circuit as claimed in claim 4, is characterized in that, gathers corresponding voltage and current value input to model self-defining parameter module with software module, accepts the output of self-defining parameter module simultaneously as voltage control current source The control source of the gate G introduces the driving voltage signal to realize the control of the working state of the IGBT and the voltage and current of each pole; The circuit structure module closely corresponds to the static and dynamic characteristics of the IGBT. 7. model self-defined parameter module as claimed in claim 5, is characterized in that, mainly comprises parasitic capacitance parameter module, MOSFET-BJT equivalent current source module and diode reverse recovery equivalent current source module; The module accepts parameters related to the circuit structure module and the switch transient model, and according to the modeling method described in claim 2, customizes the programming module and outputs corresponding parameters to the circuit structure module.