CN104516996A - Fault modeling simulation method of electric traction alternate current transmission two-level single-phase four-quadrant pulsed rectifier - Google Patents

Abstract

The invention provides a fault modeling simulation method of electric traction alternate current transmission two-level single-phase four-quadrant pulsed rectifier; the method is finished based on the working principle of two-level single-phase four-quadrant pulsed rectifier; and the specific method comprises the following steps: calculating a switch function corresponding to each fault mode of the electric traction alternate current transmission two-level single-phase four-quadrant pulsed rectifier; and calculating a state equation of the electric traction alternate current transmission two-level single-phase four-quadrant pulsed rectifier based on the calculation result of the switch function. The method is able to achieve that in off-line simulation and online real-time simulation systems, the simulation of the two-level single-phase four-quadrant pulsed rectifier under the normal working state and the fault states of different switch tubes; and the method is able to achieve the switching between the normal working state and the fault states of different switch tubes based on the state equation, thereby solving the technical problem that the current simulation model does not contain the fault simulation models.

Description

Electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode

Technical field

The invention belongs to electric traction alternating-current transmission technical field, relate to a kind of electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Background technology

For the technological development of electric and electronic technical field, usual needs adopt the mode of emulation first designed methods to be carried out to the analysis verification of theoretic, to avoid on stream due to unnecessary economic loss that the defect in technical know-how design level causes.The single-phase four-quadrant pulse rectifier of two level is mainly used in alternating current traction transmission field, is the major equipment of ac-dc conversion.When the single-phase four-quadrant pulse rectifier of two level there will be unavoidable fault in operational process, certain harm is existed to the normal operation of whole kinematic train.Now fault modeling corresponding in kinematic train and fault diagnosis research are more and more taken seriously, but so far, less to the single-phase four-quadrant pulse rectifier of two level corresponding fault simulation means.

All there is normal operating conditions and fail operation state in any power electronic equipment, for the single-phase four-quadrant pulse rectifier of two level, there is situation during switching tube fault on different brachium pontis when it normally works.On the different brachium pontis of the single-phase four-quadrant pulse rectifier of two level during switching tube failure condition, must there is change in ac-side current harmonic content, and corresponding DC side fluctuation also can be different, and this affects the performance of whole ac and dc systems to a certain extent.Therefore, carry out modeling and simulation to the single-phase four-quadrant pulse rectifier of two level, on the different brachium pontis of observational study, the impact of switching tube fault on whole AC-to-DC side is necessary very much.In current emulation technology, the single-phase four-quadrant pulse rectifier of two level nearly all only has the realistic model of normal operating conditions, still there is not the fault simulation model independently with switching tube fault mode on different brachium pontis.

The single-phase four-quadrant pulse rectifier fault simulation of existing two level also can adopt independently in some software, and IGBT and diode (led) module have been built, but, in this case emulation can easily not realize the switching of normal mode and fault mode, does not possess the situation of the single-phase four-quadrant pulse rectifier normal mode of research two level to transient changing during fault mode.

Summary of the invention

In view of first technology with deficiency of navigating, the object of this invention is to provide a kind of applicable off-line simulation and online real-time emulation system, electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode, the single-phase four-quadrant pulse rectifier fault simulation model of electric traction alternating-current transmission two level set up by the method is described based on state equation, realize the single-phase four-quadrant pulse rectifier normal operating conditions emulation of two level, switching tube fault simulation on different brachium pontis, and the switching on normal operating conditions and different brachium pontis under switching tube malfunction, make up the technical matters of non-fault realistic model in existing realistic model.

For achieving the above object, concrete technological means of the present invention is:

Electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode, under Matlab/Simulink, carry out two level four-quadrant pulsed rectifiers normally work and emulation under fault mode, defining single-phase two level pulse rectifier left side brachium pontis is A brachium pontis, the right brachium pontis is B brachium pontis, comprises the following steps:

(1), according on off state function under input pulse calculating different faults pattern:

Under different faults pattern, on off state function calculates the switching component gating pulse P by the single-phase four-quadrant pulse rectifier of electric traction alternating-current transmission two level ₁, P ₂, P ₃, P ₄complete; Under different faults pattern, on off state function calculates and comprises 11 kinds of situations, definition S _a, S _bbe respectively A, B brachium pontis switch function, at different pulsed rectifier ac-side current i _sunder, the on off state function computing method in often kind of situation are as follows:

(a) normal operation condition switch function computing method:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition on (b) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition under (c) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition on (d) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition under (e) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and A brachium pontis on (f) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation on IGBT and B brachium pontis on (g) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis on (h) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

(i) the switch function computing method of IGBT simultaneous faults situation on IGBT and B brachium pontis under A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis under (j) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis on (k) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1& i_s<0\end{array}\right.$

Wherein i _sit is the current value of the single-phase four-quadrant pulse rectifier AC of two level.

(2), by (1) gained on off state function, the single-phase four-quadrant pulse rectifier state equation of two level under different situations is calculated:

The switching function value of (1) gained is inputted following equation:

$\left\{\begin{array}{c}R=(1-S_p)R_p+R_s\\ u_{\mathrm{ab}}=(S_A-S_B)U_d\\ L_s\frac{{\mathrm{di}}_s}{\mathrm{dt}}=u_s-u_{\mathrm{ab}}-{\mathrm{Ri}}_s\\ i_d=(S_A-S_B)i_s\end{array}\right.$

Calculate and obtain: i _s, i _dand u _ab;

Wherein, S _pfor precharge switch state value, R _pfor pre-charge resistance value, R _sfor Circuit Fault on Secondary Transformer electric leakage resistance, U _dfor intermediate dc side magnitude of voltage, u _sfor Circuit Fault on Secondary Transformer output AC voltage value, L _sfor transformer secondary side leakage inductance value, i _sbe the current value of the single-phase four-quadrant pulse rectifier AC of two level, i _dit is the current value of the single-phase four-quadrant pulse rectifier DC side of two level; i _sit is the current value of the single-phase four-quadrant pulse rectifier AC of two level; u _abfor the magnitude of voltage of pulsed rectifier AC;

(3), by (2) obtain simulation value i _s, i _dand u _aboutput to traction control unit.

In the inventive method, the basic circuit diagram (shown in Fig. 1) of the single-phase four-quadrant pulse rectifier of electric traction alternating-current transmission two level, the ultimate principle figure (shown in Fig. 2) when the single-phase four-quadrant pulse rectifier of available electric traction alternating-current transmission two level normally works accordingly.During the simulation modeling of electric traction alternating-current transmission two level provided by the invention single-phase four-quadrant pulse rectifier fault modeling emulation mode to the single-phase four-quadrant pulse rectifier of two level, by in electric traction alternating-current transmission system, the pre-charge resistance all existed under the leakage inductance of two level single-phase four-quadrant pulse rectifier front end transformers and usual condition is put together consideration, considers the afterflow effect with the antiparallel diode of IGBT; Meanwhile, switching device is done idealized process, neglect the impact of the factors such as switching loss, conducting turn-off time, conduction pipe pressure drop.

The electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault simulation method that the present invention sets up can be determined: the input quantity during modeling of electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault simulation is: AC voltage u _s, DC voltage U _d, pre-charge resistance drops into/excises switch S _p/ S _k, switching component gating pulse P ₁, P ₂, P ₃, P ₄; When the single-phase four-quadrant pulse rectifier fault modeling of electric traction alternating-current transmission two level emulates, output quantity is ac-side current I _s, DC side electric current I _d; The parameter of needs setting when the single-phase four-quadrant pulse rectifier fault modeling of electric traction alternating-current transmission two level emulates is AC transformer leakage inductance L _s, leakage resistance R _s, pre-charge resistance R _pand fault mode Mode.Its schematic diagram as shown in Figure 3.

Adopt the present invention, can realize in off-line simulation and online real-time emulation system, the emulation of the single-phase four-quadrant pulse rectifier of two level in normal operation and under different switching tube malfunction, and the model based on state equation can realize the switching under normal operating conditions and different switching tube malfunction, compensate for the technical matters of non-fault realistic model in existing realistic model.The electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode set up is applicable to all based on the computer implemented off-line that carries out the single-phase four-quadrant pulse rectifier of two level in AC Drive field or real-time simulation experimental study.The emulation of the single-phase four-quadrant pulse rectifier of electric traction alternating-current transmission two level in normal operation and under different switching tube malfunction can be carried out, and two level single-phase four-quadrant pulse rectifier normal state simulation and the switching emulated under different switching tube malfunction can be realized based on the method in the present invention.

Accompanying drawing illustrates:

Fig. 1 is the basic circuit diagram of the single-phase four-quadrant pulse rectifier of electric traction alternating-current transmission two level.

Fig. 2 is the ultimate principle figure of electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier when normally working.

Fig. 3 is the principle IO interface definition figure of electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault simulation method proposed by the invention.

Fig. 4 is the process flow diagram of mdlOutputs (SimStruct*S, int_T tid) function in the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Fig. 5 is the process flow diagram of mdlDerivatives (SimStruct*S) function in the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Fig. 6 is the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Fig. 7 is the optimum configurations dialog box of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Fig. 8 is rectifier voltage on line side current waveform figure in simulation result under the normal operation of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Fig. 9 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode A brachium pontis on rectifier voltage on line side current waveform figure in simulation result under IGBT failure condition.

Figure 10 is rectifier voltage on line side current waveform figure in simulation result under IGBT failure condition under the A brachium pontis of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Figure 11 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode B brachium pontis on rectifier voltage on line side current waveform figure in simulation result under IGBT failure condition.

Figure 12 is rectifier voltage on line side current waveform figure in simulation result under IGBT failure condition under the B brachium pontis of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Figure 13 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode A brachium pontis on rectifier voltage on line side current waveform figure in simulation result in IGBT simultaneous faults situation under IGBT and A brachium pontis.

Figure 14 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode A brachium pontis on rectifier voltage on line side current waveform figure in simulation result in IGBT simultaneous faults situation on IGBT and B brachium pontis.

Figure 15 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode A brachium pontis on rectifier voltage on line side current waveform figure in simulation result in IGBT simultaneous faults situation under IGBT and B brachium pontis.

Figure 16 is rectifier voltage on line side current waveform figure in simulation result in IGBT simultaneous faults situation on IGBT and B brachium pontis under the A brachium pontis of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Figure 17 is rectifier voltage on line side current waveform figure in simulation result under IGBT simultaneous faults under IGBT and B brachium pontis under the A brachium pontis of the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode.

Figure 18 be the embodiment made under Matlab/Simulink environment based on electric traction alternating-current transmission two level of the present invention single-phase four-quadrant pulse rectifier fault modeling emulation mode B brachium pontis on rectifier voltage on line side current waveform figure in simulation result in IGBT simultaneous faults situation under IGBT and B brachium pontis.

Embodiment

Below in conjunction with accompanying drawing, carry out clear, complete description to the technical scheme in the embodiment of the present invention, obviously, described embodiment is only one embodiment of the present of invention, instead of whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art, not making the every other embodiment obtained under creative work prerequisite, belong to the scope of protection of the invention.

As the specific implementation method of a kind of two level single-phase four-quadrant pulse rectifier fault modeling emulation mode in the present invention, setting programmed environment is Matlab/Simulink, and programming language is the C language of Matlab/Simulink self.

Embodiment

The single-phase four-quadrant pulse rectifier fault model of electric traction alternating-current transmission two level set up can according to the present invention describe method and carry out:

1st step: carry out initialization by writing mdlInitializeSizes (SimStruct*S) function to model, the input port number of setting model is 8, and output port number is 2, model can setup parameter be 4, and system state variables number is 1.

2nd step: by writing mdlInitializeSampleTimes (SimStruct*S) function sets simulation time, the parameters such as simulation step length.

3rd step: carry out initialization by writing the state variable of mdlInitializeConditions (SimStruct*S) function to the state equation separated required in emulation.

4th step: by writing mdlOutputs (SimStruct*S, int_T tid) function and mdlDerivatives (SimStruct*S) function, realize the reading of input port information, model can the reading of setup parameter information, switch function calculates, resolving of state equation, and the assignment of output port information, function mdlOutputs (SimStruct*S, int_T tid) specific procedure process flow diagram as shown in Figure 4, the specific procedure process flow diagram of function mdlDerivatives (SimStruct*S) is as shown in Figure 5.

5th step: write function is compiled by the mex instruction of Matlab.And by s-function module, encapsulation setting is carried out to function under Matlab/Simulink environment.As shown in Figure 6, the optimum configurations dialog box after module package as shown in Figure 7 for packaged module.

Emulate based on ready-made model, setting PWM switching frequency is 350Hz, intermediate dc side voltage 3000V, in simulation result, as Suo Shi Fig. 8 ~ 18, (Fig. 8 is the simulation result under normal operation to electric traction alternating-current transmission two level four-quadrant pulsed rectifier voltage on line side current waveform figure, Fig. 9 is the simulation result on A brachium pontis under IGBT failure condition, Figure 10 is the simulation result under A brachium pontis under IGBT failure condition, Figure 11 is the simulation result on B brachium pontis under IGBT failure condition, Figure 12 is the simulation result under B brachium pontis under IGBT failure condition, Figure 13 is the simulation result on A brachium pontis under IGBT and A brachium pontis in IGBT simultaneous faults situation, Figure 14 is the simulation result on A brachium pontis on IGBT and B brachium pontis in IGBT simultaneous faults situation, Figure 15 is the simulation result on A brachium pontis under IGBT and B brachium pontis in IGBT simultaneous faults situation, Figure 16 is the simulation result under A brachium pontis on IGBT and B brachium pontis in IGBT simultaneous faults situation, Figure 17 is the simulation result under A brachium pontis under IGBT and B brachium pontis under IGBT simultaneous faults, Figure 18 is the simulation result of IGBT simultaneous faults situation under IGBT and B brachium pontis on B brachium pontis).

The above is exactly one embodiment of the present invention, two level four-quadrant pulsed rectifiers can be carried out based on this embodiment under Matlab/Simulink normally to work and emulation under fault mode, two level four-quadrant pulsed rectifiers can also be carried out based on this embodiment in the real-time simulation machine that dSPACE or RT_Lab etc. is similar normally to work and emulation under fault mode, normally work and control algolithm etc. under fault mode to study two level four-quadrant pulsed rectifiers.It should be pointed out that for those skilled in the art, under the premise without departing from the principles of the invention, can also make some improvements and modifications, these improvements and modifications also should be considered as protection scope of the present invention.

Claims (1)

1. electric traction alternating-current transmission two level single-phase four-quadrant pulse rectifier fault modeling emulation mode, under Matlab/Simulink, carry out two level four-quadrant pulsed rectifiers normally work and emulation under fault mode, defining single-phase two level pulse rectifier left side brachium pontis is A brachium pontis, the right brachium pontis is B brachium pontis, comprises the following steps:

(1), according on off state function under input pulse calculating different faults pattern:

Under different faults pattern, on off state function calculates the switching component gating pulse P by the single-phase four-quadrant pulse rectifier of electric traction alternating-current transmission two level ₁, P ₂, P ₃, P ₄complete; Under different faults pattern, on off state function calculates and comprises 11 kinds of situations, definition S _a, S _bbe respectively A, B brachium pontis switch function, at different pulsed rectifier ac-side current i _sunder, the on off state function computing method in often kind of situation are as follows:

(a) normal operation condition switch function computing method:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition on (b) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition under (c) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition on (d) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT failure condition under (e) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and A brachium pontis on (f) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation on IGBT and B brachium pontis on (g) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis on (h) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ 0& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

(i) the switch function computing method of IGBT simultaneous faults situation on IGBT and B brachium pontis under A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1-P_4& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis under (j) A brachium pontis:

$S_A=\left\{\begin{array}{cc}1& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}{P}_3& i_s>0\\ 1& i_s<0\end{array}\right.$

The switch function computing method of IGBT simultaneous faults situation under IGBT and B brachium pontis on (k) B brachium pontis:

$S_A=\left\{\begin{array}{cc}1-P_2& i_s>0\\ P_1& i_s<0\end{array}\right.,S_B=\left\{\begin{array}{cc}0& i_s>0\\ 1& i_s<0\end{array}\right.$

Wherein i _sit is the current value of the single-phase four-quadrant pulse rectifier AC of two level.

(2), by (1) gained on off state function, the single-phase four-quadrant pulse rectifier state equation of two level under different situations is calculated:

The switching function value of (1) gained is inputted following equation:

$\left\{\begin{array}{c}R=(1-S_p)R_p+R_s\\ u_{\mathrm{ab}}=(S_A-S_B)U_d\\ L_s\frac{{\mathrm{di}}_s}{\mathrm{dt}}=u_s-u_{\mathrm{ab}}-{\mathrm{Ri}}_s\\ i_d=(S_A-S_B)i_s\end{array}\right.$

Calculate and obtain: i _s, i _dand u _ab;

Wherein, S _pfor precharge switch state value, R _pfor pre-charge resistance value, R _sfor Circuit Fault on Secondary Transformer electric leakage resistance, U _dfor intermediate dc side magnitude of voltage, u _sfor Circuit Fault on Secondary Transformer output AC voltage value, L _sfor transformer secondary side leakage inductance value, i _sbe the current value of the single-phase four-quadrant pulse rectifier AC of two level, i _dit is the current value of the single-phase four-quadrant pulse rectifier DC side of two level; i _sit is the current value of the single-phase four-quadrant pulse rectifier AC of two level; u _abfor the magnitude of voltage of pulsed rectifier AC;

(3), by (2) obtain simulation value i _s, i _dand u _aboutput to traction control unit.