CN103701394A - Current-magnitude-based open-circuit failure online-diagnosis method for power tube of inverter - Google Patents

Abstract

The invention discloses a current-magnitude-based open-circuit failure online-diagnosis method for a power tube of an inverter, belongs to the field of motor control, and aims to solve the problem of poor robustness of a current-magnitude-based open-circuit failure diagnosis technology for the power tube of the inverter. The method comprises the following steps of establishing a current observer model of a permanent magnet synchronous motor driving system in a failure-free state, comparing an observed current value with detection current to obtain a three-phase current residual, converting the three-phase current residual to a two-phase coordinate system in a coordinate conversion way to obtain a current residual vector, standardizing the current residual vector, and diagnosing and positioning an open-circuit failure of the power tube of the inverter according to the amplitude and the phase of the standardized current residual vector. The current-magnitude-based open-circuit failure online-diagnosis method for the power tube of the inverter is free of influence of a system closed-loop control algorithm and insensitive to loads, and has higher robustness to parameter errors, measurement errors, system disturbance and the like.

Description

A kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current

Technical field

The present invention relates to a kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current, belong to Motor Control Field.

Background technology

The PMSM Drive System of voltage source inverter power supply is widely applied in fields such as industry, electric automobile, military affairs, space flight and aviation with its superior performance and higher efficiency.Yet, due to the fragility of power electronic device and drive circuit thereof, the weak link that inverter is become easily break down in system.After inverter breaks down, be operated in abnormal condition, will cause motor output torque to reduce and fluctuation, affect systematic function, and increase the voltage and current stress of other devices, heavy can make system be absorbed in collapse, so need to diagnose in time.The short circuit of power switch pipe and open circuit are the common faults of inverter, and the driving signal of mistake, accessory power supply inefficacy, device over-voltage breakdown, avalanche breakdown, thermal breakdown etc. all can cause the short trouble of power tube; The reason that causes power tube to open a way mainly contains device breakage, binding line fracture or welding and comes off, drives dropout or circuit malfunction etc.Short trouble is difficult to be diagnosed because of life period extremely short (conventionally in 10 μ s); therefore the diagnosis and protection of short trouble adopts the design based on hardware circuit more; the detections such as at present overvoltage, overcurrent, short circuit, overheated and drive circuit is under-voltage and protective circuit have been applied in inverter; these GPF (General Protection False circuit have become a standard in Intelligent Power Module (IPM), have ensured to a certain extent the safe operation of inverter.Yet, for the open fault of power tube, but need to take the fault message of certain technological means extraction system to realize diagnosis and location.

The popularity of inverter applications and fragility have great importance its failure diagnosis, and researcher has proposed the diagnostic method of many inverter open faults.

The diagnostic method > > of the three-phase inverter IGBT open fault of Chinese patent < < based on power output, publication number is CN130278727A, open day is on September 4th, 2013, disclose a kind of method of utilizing six and half wave powers and setting threshold in one-period relatively to diagnose inverter IGBT open fault, the method can detect and orient any one or any two IGBT power tubes of open circuit simultaneously.

Chinese patent < < invertor operation state shows and fault on-line diagnosis circuit > >, publication number is CN101201391, open day is on June 18th, 2008, disclose a kind of three-phase bridge rectifier circuit that utilizes photoelectricity testing part to form and realized demonstration and the inline diagnosis of invertor operation state, advantage is that circuit is simple.

The device open fault diagnostic circuit > > of Chinese patent < < diode neutral-point-clamped three-level inverter, publication number is CN102937688A, open day is on February 20th, 2013, utilize three identical open fault diagnosis unit circuit of structure to detect the device open fault in three-level inverter, there is the fireballing advantage of diagnosis.

The on-line measuring device of Chinese patent application < < open-circuit fault of power tubes of inverter and detection method > >, application number is 201010135717.9, open day is on September 22nd, 2010, a kind of employing photoelectrical coupler indirect detection power tube voltage is disclosed, in conjunction with logical circuit and switching signal rising edge delay circuit, realize the method that open-circuit fault of power tubes is diagnosed, diagnostic circuit is simple, and diagnosis speed is fast.

The Chinese patent < < common open circuit fault diagnostic method of brshless DC motor inverter > >, publication number is CN102998588A, open day is on March 27th, 2013, by detecting this stage electric current, determine this stage conducting state matrix; Then according to this stage current detection signal, export fault position signal; Ask again before this stage conducting matrix in one-period with matrix Q, by the number of 0 element and number and the position that tracing trouble pipe is carried out in position in judgement and matrix Q.The method is applicable to the diagnosis of inverter open fault in BLDCM Drive System.

In patent and document for open-circuit fault of power tubes of inverter diagnosis, diagnostic method roughly can be divided into two classes: a class is the diagnostic techniques based on system power amount, these class methods are utilized the original current feedback amount of system, do not need additional sensors, shortcoming is to depend on load, be subject to the impact of system closed loop control algorithm, and comparatively responsive to transient process, poor robustness; Other class methods are the diagnostic techniques based on system voltage amount, and these class methods are independent of load, and robustness is good, and diagnosis speed is fast, but need extra voltage sensor, have increased hardware cost and the complexity of system.

Summary of the invention

The present invention seeks in order to solve the problem of the poor robustness of the open-circuit fault of power tubes of inverter diagnostic techniques based on the magnitude of current, a kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current is provided.

Open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current of the present invention, the PMSM Drive System that the method relates to comprises rectifier, DC filter capacitor, inverter, current sensor, permagnetic synchronous motor, position transducer, controller and isolation and drive circuit;

Inverter is by power tube T ₁, T ₂..., T ₆form, A phase brachium pontis is by T ₁and T ₂form, B phase brachium pontis is by T ₃and T ₄form, C phase brachium pontis is by T ₅and T ₆form T ₁, T ₃and T ₅for upper brachium pontis, T ₂, T ₄and T ₆for lower brachium pontis;

The DC output end parallel connection direct filter capacitor of rectifier, the DC output end of rectifier also connects the direct-flow input end of inverter, and the ac output end of inverter connects permagnetic synchronous motor;

Current sensor gathers the three-phase current signal i=[i of permagnetic synchronous motor _a, i _b, i _c] export to controller, i _afor A detects electric current, i mutually _bfor B detects electric current, i mutually _cfor C detects electric current mutually;

The position signalling θ that position transducer gathers permagnetic synchronous motor exports to controller;

Controller output switching signal S ₁, S ₂..., S ₆by isolation and drive circuit, load the drive end to six power tubes in inverter;

The method comprises the following steps:

Step 1, employing hybrid system current observer are observed the current signal of permagnetic synchronous motor, and are obtained electric current measured value $\hat{i}={\left[\begin{array}{ccc}{\hat{i}}_a& {\hat{i}}_b& {\hat{i}}_c\end{array}\right]}^T,$ Wherein,

for A phase current measured value,

for B phase current measured value, for C phase current measured value;

Step 2, by electric current measured value compare with the three-phase current signal i of current sensor collection, obtain three-phase current residual error $\tilde{i}=\left[\begin{array}{ccc}{\tilde{i}}_a& {\tilde{i}}_b& {\tilde{i}}_c\end{array}\right],$ A phase residual error

b phase residual error

with C phase residual error

by following formula, obtain:

$\left\{\begin{array}{c}{\tilde{i}}_a=i_a-{\hat{i}}_a\\ {\tilde{i}}_b=i_b-{\hat{i}}_b\\ {\tilde{i}}_c=i_c-{\hat{i}}_c\end{array}\right.;$

Step 3, utilize conversion that three phase static coordinate is tied to two-phase rest frame by three-phase current residual error be transformed to

wherein

for α shaft current residual error,

for β shaft current residual error;

Step 4, ask for standardized electric current residual error vector

wherein: | r| is the amplitude of standardization electric current residual error vector r, and δ is standardized residual vector phase;

R=[r _ar _br _c], r _afor standardized A phase current residual error, r _bfor standardization B phase current residual error, r _cfor standardization C phase current residual error;

Step 5, by the amplitude of standardization electric current residual error vector r | the threshold value R of r| and setting _thcompare, judged whether that open-circuit fault of power tubes occurs: when | r|≤R _thtime, fault-free, then returns to execution step one; When | r| > R _thtime, there is fault, then, execution step six; Here threshold value R _thconventionally be chosen for 1;

Step 6, according to table 1 location, there is the power tube of open fault:

Table 1

Complete the diagnosis of open-circuit fault of power tubes of inverter.

Advantage of the present invention: diagnostic method of the present invention is independent of outside systematic control algorithm, is not therefore subject to the impact of system closed loop control algorithm; To the standardization of electric current residual error vector, make this diagnostic method insensitive to load; Meanwhile, owing to adopting threshold value and sector, the method has good robustness to parameter error, measure error and system disturbance etc.

Accompanying drawing explanation

Fig. 1 is the PMSM Drive System structure chart that the inventive method relates to;

Fig. 2 is the theory diagram of the open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current of the present invention;

Fig. 3 is the ideal trajectory of standard galvanic current residual error vector under open-circuit fault of power tubes of the present invention;

Figure is cut apart in threshold value setting and sector when Fig. 4 is fault diagnosis and location of the present invention;

The simulation result of Fig. 5 method for diagnosing faults of the present invention.

Embodiment

Embodiment one: present embodiment is described below in conjunction with Fig. 1 to Fig. 5, a kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current described in present embodiment, the PMSM Drive System that the method relates to comprises rectifier 1, DC filter capacitor 2, inverter 3, current sensor 4, permagnetic synchronous motor 5, position transducer 6, controller 7 and isolation and drive circuit 8; As shown in Figure 1;

Inverter 3 is by power tube T ₁, T ₂..., T ₆form, A phase brachium pontis is by T ₁and T ₂form, B phase brachium pontis is by T ₃and T ₄form, C phase brachium pontis is by T ₅and T ₆form T ₁, T ₃and T ₅for upper brachium pontis, T ₂, T ₄and T ₆for lower brachium pontis;

The DC output end parallel connection direct filter capacitor 2 of rectifier 1, the DC output end of rectifier 1 also connects the direct-flow input end of inverter 3, and the ac output end of inverter 3 connects permagnetic synchronous motor 5;

Current sensor 4 gathers the three-phase current signal i=[i of permagnetic synchronous motor 5 _a, i _b, i _c] export to controller 7, i _afor A detects electric current, i mutually _bfor B detects electric current, i mutually _cfor C detects electric current mutually;

The position signalling θ that position transducer 6 gathers permagnetic synchronous motor 5 exports to controller 7;

Controller 7 output switching signal S ₁, S ₂..., S ₆the drive end loading to six power tubes in inverter 3 by isolation and drive circuit 8;

It is characterized in that, the method comprises the following steps:

Step 1, employing hybrid system current observer are observed the current signal of permagnetic synchronous motor 5, and are obtained electric current measured value $\hat{i}={\left[\begin{array}{ccc}{\hat{i}}_a& {\hat{i}}_b& {\hat{i}}_c\end{array}\right]}^T,$ Wherein,

for A phase current measured value,

for B phase current measured value,

for C phase current measured value;

Step 2, by electric current measured value

the three-phase current signal i gathering with current sensor 4 compares, and obtains three-phase current residual error $\tilde{i}=\left[\begin{array}{ccc}{\tilde{i}}_a& {\tilde{i}}_b& {\tilde{i}}_c\end{array}\right],$ A phase residual error

b phase residual error

with C phase residual error

by following formula, obtain:

$\left\{\begin{array}{c}{\tilde{i}}_a=i_a-{\hat{i}}_a\\ {\tilde{i}}_b=i_b-{\hat{i}}_b\\ {\tilde{i}}_c=i_c-{\hat{i}}_c\end{array}\right.;$

Step 3, utilize conversion that three phase static coordinate is tied to two-phase rest frame by three-phase current residual error be transformed to

wherein

for α shaft current residual error,

for β shaft current residual error;

Step 4, ask for standardized electric current residual error vector

wherein: | r| is the amplitude of standardization electric current residual error vector r, and δ is standardized residual vector phase;

R=[r _ar _br _c], r _afor standardized A phase current residual error, r _bfor standardization B phase current residual error, r _cfor standardization C phase current residual error;

Step 5, by the amplitude of standardization electric current residual error vector r | the threshold value R of r| and setting _thcompare, judged whether that open-circuit fault of power tubes occurs: when | r|≤R _thtime, fault-free, then returns to execution step one; When | r| > R _thtime, there is fault, then, execution step six; Here threshold value R _thconventionally be chosen for 1;

Step 6, according to table 1 location, there is the power tube of open fault:

Table 1

Complete the diagnosis of open-circuit fault of power tubes of inverter.

Method described in present embodiment, theory diagram shown in Figure 2 describes, first utilize Hybrid System Theory to set up the current observer model of PMSM Drive System under unfaulty conditions, then electric current measured value is compared with detection electric current, obtain three-phase current residual error, utilized coordinate transform to be transformed into and under two phase coordinate systems, obtained electric current residual error vector, and to the standardization of electric current residual error vector, the open fault of finally diagnosing and locate inverter power pipe according to the amplitude of standardization electric current residual error vector and phase place.Open-circuit fault of power tubes of inverter inline diagnosis method based on standardization electric current residual error vector disclosed by the invention, be not subject to the impact of system closed loop control algorithm, insensitive to load, parameter error, measure error and system disturbance etc. are had to good robustness, in fields such as the higher space flight and aviation of reliability requirement, electric automobiles, have higher actual application value.

Described in present embodiment, method employing threshold value is to be relatively to eliminate the impacts such as observer model parameter error, measure error, load disturbance and noise, improves the robustness of diagnostic method.

When there is open-circuit fault of power tubes, Fig. 3 has described the ideal trajectory of standardization electric current residual error vector and the corresponding relation of fault power pipe: when on certain phase brachium pontis, open fault occurs pipe, standardization electric current residual error vector locus is positioned on the negative semiaxis of this phase axis; When under certain phase brachium pontis, open fault occurs pipe, standardization electric current residual error vector locus is positioned at the positive axis of this phase axis; When certain phase brachium pontis, manage up and down while there is open fault, standardization electric current residual error vector locus is positioned on this mutually whole axis simultaneously.Standardization three-phase current residual error and standardized residual vector phase that open fault power tube is corresponding are as shown in table 1.

For eliminating the impacts such as observer model parameter error, measure error, load disturbance and noise, below by dividing sector, improve the robustness of diagnostic method.α β coordinate plane is divided into 6 sectors, and each sector is 60 °, and Fig. 4 is sector map, and table 2 is allocation table.Breakdown switch corresponding when sector is distributed and standardized residual vector is positioned at certain sector is as shown in the table.As shown in Figure 5, method for diagnosing faults of the present invention still can obtain reliable diagnosis to simulation result under the conditions such as parameter error, load disturbance.

Table 2

Sector number	Angular range	Open fault power tube
			I	–π/6～π/6	T 2
II	π/6～π/2	T 5
			III	π/2～5π/6	T 4
IV	5π/6～7π/6	T 1
			V	7π/6～3π/2	T 6
VI	3π/2～11π/6	T 3

Embodiment two: present embodiment is described further execution mode one, adopts hybrid system current observer to observe the current signal of permagnetic synchronous motor 5 in step 1, and obtains electric current measured value $\hat{i}={\left[\begin{array}{ccc}{\hat{i}}_a& {\hat{i}}_b& {\hat{i}}_c\end{array}\right]}^T,$ Process be:

Press model current signal to permagnetic synchronous motor 5 is observed,

Wherein:

for

derivative to the time;

Switching signal s=[s ₁s ₃s ₅] ^tdiscrete input vector for system;

E=[e _ae _be _c] ^tback-emf vector for permagnetic synchronous motor 5;

Coefficient of regime matrix $A=\left[\begin{array}{ccc}-\frac{\mathrm{<figure-callout\; id="0"\; label="R\; L"\; filenames="HDA0000449485660000021.png,HDA0000449485660000032.png"\; state="\{\{state\}\}">R</figure-callout>}}{L}& 0& 0\\ 0& -\frac{\mathrm{<figure-callout\; id="0"\; label="R\; L"\; filenames="HDA0000449485660000021.png,HDA0000449485660000032.png"\; state="\{\{state\}\}">R</figure-callout>}}{L}& 0\\ 0& 0& -\frac{R}{L}\end{array}\right],$ R and L are respectively winding resistance and the inductance of permagnetic synchronous motor 5;

Continuous input coefficient matrix $B_1=\left[\begin{array}{ccc}-\frac{1}{\mathrm{<figure-callout\; id="0"\; label="L"\; filenames="HDA0000449485660000021.png,HDA0000449485660000032.png"\; state="\{\{state\}\}">L</figure-callout>}}& 0& 0\\ 0& -\frac{1}{\mathrm{<figure-callout\; id="0"\; label="L"\; filenames="HDA0000449485660000021.png,HDA0000449485660000032.png"\; state="\{\{state\}\}">L</figure-callout>}}& 0\\ 0& 0& -\frac{1}{L}\end{array}\right];$

Discrete input coefficient matrix $B_{}$ ${}_2=\frac{V_{\mathrm{dc}}}{3L}\left[\begin{array}{ccc}2& -1& -1\\ -1& 2& -1\\ -1& -1& 2\end{array}\right],$ V _dcfor the DC bus-bar voltage being obtained by rectifier 1;

Back-emf vector e=-ω ψ _r[sin θ sin (π/3, θ-2) sin (π/3, θ+2)] ^t, in formula, ω is the rotor speed of permagnetic synchronous motor 5, ψ _rfor the permanent magnetism magnetic linkage of permagnetic synchronous motor 5, θ is the rotor position angle of permagnetic synchronous motor 5.

Embodiment three: present embodiment is described further execution mode one, α shaft current residual error in step 3

β shaft current residual error

by following formula, obtain:

$\left[\begin{array}{c}{\tilde{i}}_{\mathrm{\&alpha;}}\\ {\tilde{i}}_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]\left[\begin{array}{c}{\tilde{i}}_a\\ {\tilde{i}}_b\\ {\tilde{i}}_c\end{array}\right].$

Claims (3)

1. the open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current, the PMSM Drive System that the method relates to comprises rectifier (1), DC filter capacitor (2), inverter (3), current sensor (4), permagnetic synchronous motor (5), position transducer (6), controller (7) and isolation and drive circuit (8);

Inverter (3) is by power tube T ₁, T ₂..., T ₆form, A phase brachium pontis is by T ₁and T ₂form, B phase brachium pontis is by T ₃and T ₄form, C phase brachium pontis is by T ₅and T ₆form T ₁, T ₃and T ₅for upper brachium pontis, T ₂, T ₄and T ₆for lower brachium pontis;

The DC output end parallel connection direct filter capacitor (2) of rectifier (1), the DC output end of rectifier (1) also connects the direct-flow input end of inverter (3), and the ac output end of inverter (3) connects permagnetic synchronous motor (5);

Current sensor (4) gathers the three-phase current signal i=[i of permagnetic synchronous motor (5) _a, i _b, i _c] export to controller (7), i _afor A detects electric current, i mutually _bfor B detects electric current, i mutually _cfor C detects electric current mutually;

The position signalling θ that position transducer (6) gathers permagnetic synchronous motor (5) exports to controller (7);

Controller (7) output switching signal S ₁, S ₂..., S ₆by isolation and drive circuit (8), load the drive end to six power tubes in inverter (3);

It is characterized in that, the method comprises the following steps:

Step 1, employing hybrid system current observer are observed the current signal of permagnetic synchronous motor (5), and are obtained electric current measured value $\hat{i}={\left[\begin{array}{ccc}{\hat{i}}_a& {\hat{i}}_b& {\hat{i}}_c\end{array}\right]}^T,$ Wherein,

for A phase current measured value,

for B phase current measured value,

for C phase current measured value;

Step 2, by electric current measured value

the three-phase current signal i gathering with current sensor (4) compares, and obtains three-phase current residual error $\tilde{i}=\left[\begin{array}{ccc}{\tilde{i}}_a& {\tilde{i}}_b& {\tilde{i}}_c\end{array}\right],$ A phase residual error

b phase residual error with C phase residual error by following formula, obtain:

$\left\{\begin{array}{c}{\tilde{i}}_a=i_a-{\hat{i}}_a\\ {\tilde{i}}_b=i_b-{\hat{i}}_b\\ {\tilde{i}}_c=i_c-{\hat{i}}_c\end{array}\right.;$

Step 3, utilize conversion that three phase static coordinate is tied to two-phase rest frame by three-phase current residual error

be transformed to

wherein

for α shaft current residual error,

for β shaft current residual error;

Step 4, ask for standardized electric current residual error vector

wherein: | r| is the amplitude of standardization electric current residual error vector r, and δ is standardized residual vector phase;

R=[r _ar _br _c], r _afor standardized A phase current residual error, r _bfor standardization B phase current residual error, r _cfor standardization C phase current residual error;

Step 5, by the amplitude of standardization electric current residual error vector r | the threshold value R of r| and setting _thcompare, judged whether that open-circuit fault of power tubes occurs: when | r|≤R _thtime, fault-free, then returns to execution step one; When | r| > R _thtime, there is fault, then, execution step six; Here threshold value R _thconventionally be chosen for 1;

Step 6, according to table 1 location, there is the power tube of open fault:

Table 1

Complete the diagnosis of open-circuit fault of power tubes of inverter.

2. a kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current according to claim 1, is characterized in that, adopts hybrid system current observer to observe the current signal of permagnetic synchronous motor (5), and obtain electric current measured value in step 1 $\hat{i}={\left[\begin{array}{ccc}{\hat{i}}_a& {\hat{i}}_b& {\hat{i}}_c\end{array}\right]}^T$ Process be:

Press model

current signal to permagnetic synchronous motor (5) is observed,

Wherein: for

derivative to the time;

Switching signal s=[s ₁s ₃s ₅] ^tdiscrete input vector for system;

E=[e _ae _be _c] ^tback-emf vector for permagnetic synchronous motor (5);

Coefficient of regime matrix $A=\left[\begin{array}{ccc}-\frac{R}{L}& 0& 0\\ 0& -\frac{R}{L}& 0\\ 0& 0& -\frac{R}{L}\end{array}\right],$ R and L are respectively winding resistance and the inductance of permagnetic synchronous motor (5);

Continuous input coefficient matrix $B_1=\left[\begin{array}{ccc}-\frac{1}{L}& 0& 0\\ 0& -\frac{1}{L}& 0\\ 0& 0& -\frac{1}{L}\end{array}\right];$

Discrete input coefficient matrix $B_2=\frac{V_{\mathrm{dc}}}{3L}\left[\begin{array}{ccc}2& -1& -1\\ -1& 2& -1\\ -1& -1& 2\end{array}\right],$ V _dcfor the DC bus-bar voltage being obtained by rectifier (1);

Back-emf vector e=-ω ψ _r[sin θ sin (π/3, θ-2) sin (π/3, θ+2)] ^t, in formula, ω is the rotor speed of permagnetic synchronous motor (5), ψ _rfor the permanent magnetism magnetic linkage of permagnetic synchronous motor (5), θ is the rotor position angle of permagnetic synchronous motor (5).

3. a kind of open-circuit fault of power tubes of inverter inline diagnosis method based on the magnitude of current according to claim 1, is characterized in that α shaft current residual error in step 3 β shaft current residual error

by following formula, obtain:

$\left[\begin{array}{c}{\tilde{i}}_{\mathrm{\&alpha;}}\\ {\tilde{i}}_{\mathrm{\&beta;}}\end{array}\right]=\frac{2}{3}\left[\begin{array}{ccc}1& -\frac{1}{2}& -\frac{1}{2}\\ 0& \sqrt{3}/2& -\sqrt{3}/2\end{array}\right]\left[\begin{array}{c}{\tilde{i}}_a\\ {\tilde{i}}_b\\ {\tilde{i}}_c\end{array}\right].$

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