CN106124914A - Open-circuit fault of power tubes of inverter real-time detection method in motor driven systems - Google Patents

Abstract

The invention discloses open-circuit fault of power tubes of inverter real-time detection method in a kind of motor driven systems, belong to online measuring technique field.The present invention includes the speed designs sliding window length measured according to velocity sensor, as the vector dimension of current sensor measurement three-phase current sampled point；Current phasor is carried out data reconstruction so that the data phase after reconstruct is identical；Then determine fault brachium pontis by the correlation coefficient between any biphase current of design, determine the position of fault pipe by the meansigma methods of current sample point in the cycle of design.The present invention is any single tube of inverter and the diagnosis of any two-tube open fault be applicable to any three phase electric machine drive system, has low cost, accuracy of detection is high, speed is fast, real-time is high, robustness is good and capacity of resisting disturbance is a strong advantage.

Description

Open-circuit fault of power tubes of inverter real-time detection method in motor driven systems

Technical field

The invention belongs to online measuring technique field, more particularly, to inverter power in a kind of motor driven systems Tube open circuit fault real-time detection method.

Background technology

At present, the device that alternating current generator is changed as electric energy and mechanical energy, at Aero-Space, military affairs, industry, locomotive traction The field such as system and boats and ships is widely used, and presents the trend replacing direct current generator completely.Inverter is as alternating current Core component in machine drive system, is the weak link being easiest in drive system break down, and wherein power tube is due to height Frequency is opened, to turn off the open fault caused especially pronounced, directly affects the properly functioning of motor driven systems.For inverter merit The method that the open fault of rate pipe proposes effectively to detect, position and isolate in real time, it is provided that the most effective information is given follow-up Faults-tolerant control strategy, has important engineer applied to the reliability improving motor driven systems and is worth.

In prior art, there are three kinds about open-circuit fault of power tubes of inverter real-time detection method: 1, based on motor model, Design observer, if the residual error of the output of observer and real system output is more than the threshold value set, then judge that system occurs event Barrier.This method depends greatly on the parameter of electric machine, and in actual motion, the parameter of motor is the uncertain, therefore of change Certain deficiency is there is in this method in engineer applied；2, method based on detection voltage, abnormal according to fault power tube voltage Become characteristic, carry out the most real-time detection and location, this class method need add on hardware corresponding sensor and Testing circuit, improves the cost of monitoring system；3, method based on detection electric current, according to the three-phase current of inverter output, Analyzing system failure mechanism respectively in coordinate system and coordinate system, carry out the most real-time detection and location, this kind of method needs Estimation synchronous rotary angle, estimation error can affect accuracy of detection.

Summary of the invention

For disadvantages described above or the Improvement requirement of prior art, the present invention provides inverter merit in a kind of motor driven systems Rate tube open circuit fault real-time detection method, its object is to improve existing open-circuit fault of power tubes real-time detection method, improves Detection speed, strengthens algorithm robustness, reduces testing cost.

The present invention provides open-circuit fault of power tubes of inverter real-time detection method in a kind of motor driven systems, including following Step:

Step 1, the width of calculating sliding windowWherein, T_sRepresenting the sampling period of electric current loop, n represents electricity Machine rotating speed, p represents the number of pole-pairs of motor；

Step 2, design three-phase current vector, the data of reconstruct current phasor make its same phase:

First, the sampled point in the cycle is stored in vector I_a,I_b,I_cIn, its dimension is L, adopts at each electric current Sample moment k, current phasor I_a,I_b,I_cAbandon a sampled point I of most end_a(1),I_b(1),I_c(1), sampled point will then be remained In vector, move to left one, up-to-date sampled point is added I simultaneously_a,I_b,I_c, it is designated as I_a(L),I_b(L),I_c(L), it is achieved data Real-time online updates；

Then, in each current sample moment, current phasor is carried out data reconstruction, as shown in formula (1):

$\begin{array}{cc}\left\{\begin{array}{c}{D}_a=I_a\\ D_b=\[I_b\[1/3L:L\],I_b\[1:1/3L-1\]\]\\ D_c=\[I_c\[2/3L:L\],I_c\[1:2/3/L-1\]\]\end{array}\right.& \backslash *MERGEFORMAT\end{array}---\left(1\right)$

In formula, I_b(1/3L:L) represent one section of current sample point, from the beginning of the 1/3L of position, terminate with position L.

Step 3, fault characteristic value extract, and design two characteristic quantity functions for fault diagnosis and location:

Fault characteristic value one: current phasor meansigma methods, shown in equation below (2):

$\begin{array}{cc}\begin{array}{c}{S}_m=\frac{\underset{i=1}{\overset{L}{\Σ}}{D}_m\left(i\right)}{L}\\ m=a,b,c\end{array}& \backslash *MERGEFORMAT\end{array}---\left(2\right)$

Fault characteristic value two: the arbitrarily correlation coefficient of biphase current, shown in equation below (3):

$\begin{array}{cc}\begin{array}{c}{X}_{mm}=\frac{\underset{i=1}{\overset{L}{\Σ}}\left|(D_m-S_m)(D_n-S_n)\right|}{\sqrt{\left(\underset{i=1}{\overset{L}{\Σ}}{(D_m-S_m)}^2\right)\left(\underset{i=1}{\overset{L}{\Σ}}{(D_n-S_n)}^2\right)}}\\ (m,n=a,b,c;m\≠n)\end{array}& \backslash *MERGEFORMAT\end{array}---\left(3\right).$

Step 4, according to design fault characteristic value carry out fault diagnosis, fault diagnosis includes fault detect and fault location Two links, current phasor relevance function value approximately equal after any two phase reconstructions that and if only and if when be 1, system Being in health status, fault-free occurs；System detects fault, gives fault alarm；In the case of system detects fault, Fault type is positioned with current phasor meansigma methods, then by institute according to the current phasor relevance function value after any two phase reconstructions Two fault characteristic value obtained detect and position fault power pipe.

In general, by the contemplated above technical scheme of the present invention compared with prior art, there is following useful effect Really: the present invention can detect the feelings of any three-phase drive system single tube fault and the open fault with the two-tube fault of brachium pontis in real time Condition, it is possible to be accurately positioned fault power pipe.The present invention is applicable to synchronous motor, asynchronous machine current closed-loop or opened loop control The system of strategy, and the on-line checking of the drive system open-circuit fault of power tubes of 5 phases (heterogeneous) motor is had directive significance.

(1) low cost, the present invention is be applicable to the system of any employing vector control strategy, it is not necessary to extra voltage passes Sensor；It is also applied for open-circuit fault of power tubes of inverter diagnosis in three phase electric machine open current loop control system；

(2) accuracy of detection is high, and speed is fast, and real-time is high.The present invention can detect in converter the most single the most accurately Pipe or two-tube open fault and secondary failure；

(3) robustness is good, and capacity of resisting disturbance is strong.The dynamic processes such as electric motor starting, speed change, impact or anticlimax load will not The fault diagnosis result of the present invention is produced negative influence；And the program is insensitive to motor internal parameter, noise resisting ability is strong；

(4) realizing simply, the present invention can be embedded in control program as a subprogram, does not affect without amendment Control program.

Accompanying drawing explanation

Fig. 1 is the inverter in motor driven systems of the present invention in open-circuit fault of power tubes of inverter real-time detection method Topological structure.

Fig. 2 is the flow chart of open-circuit fault of power tubes of inverter real-time detection method in motor driven systems of the present invention.

Detailed description of the invention

In order to make the purpose of the present invention, technical scheme and advantage clearer, below in conjunction with drawings and Examples, right The present invention is further elaborated.Should be appreciated that specific embodiment described herein only in order to explain the present invention, and It is not used in the restriction present invention.If additionally, technical characteristic involved in each embodiment of invention described below The conflict of not constituting each other just can be mutually combined.

Fig. 1 show the topology knot of the motor driven systems three-phase voltage source inverter of tape jam diagnostic module in the present invention Structure, ignores the nonlinear operation curve of power tube (IGBT), and under health or malfunction, 6 power tube T1～T6 are whole Or there is symmetry, wherein U on the topology in part_dIt is DC voltage, C₁、C₂Direct-current chain electric capacity, D1, D2, D3, D4, D5, D6 are respectively the diode that each power tube is subsidiary, i_a、i_b、i_cElectric current is exported for three-phase.Traditional control module includes vowing Amount control system and PWM drive signal, the fault diagnosis module newly increased includes that data reconstruction, relevance function and fault are examined Disconnected.

Fig. 2 show the implementing procedure figure that the present invention is concrete, comprises the steps of:

Step 1, asking for the width L of sliding window according to sliding window computing formula, its concrete computing formula isWherein, T represents the power-up period of electrical network, T_sRepresenting the sampling period of electric current loop, n represents that rotor turns Speed, p represents the number of pole-pairs of motor, the current sample number of times that the width L of sliding window is numerically equal in power-up period.

Step 2, design three-phase current vector, reconstruct three-phase current vector data.Design three-phase current vector, reconstructs electric current The data of vector make its same phase.First, the sampled point in the cycle is stored in vector I_a,I_b,I_cIn, its dimension is L, at each current sample moment k, current phasor I_a,I_b,I_cAbandon a sampled point I of most end_a(1),I_b(1),I_c(1), Then residue sampled point is moved to left one in vector, up-to-date sampled point is added I simultaneously_a,I_b,I_c, it is designated as I_a(L),I_b (L),I_c(L), it is achieved data real-time online updates.Then, in each current sample moment, current phasor is carried out data weight Structure, as shown in formula (1).

$\begin{array}{cc}\left\{\begin{array}{c}{D}_a=I_a\\ D_b=\[I_b\[1/3L:L\],I_b\[1:1/3L-1\]\]\\ D_c=\[I_c\[2/3L:L\],I_c\[1:2/3/L-1\]\]\end{array}\right.& \backslash *MERGEFORMAT\end{array}---\left(1\right)$

In formula, I_b(1/3L:L) represent one section of current sample point, from the beginning of the 1/3L of position, terminate with position L.

Step 3, fault characteristic value extract: two characteristic quantity functions of design are for fault diagnosis and location here, and fault is special The amount of levying one: current phasor meansigma methods, shown in equation below (2):

$\begin{array}{cc}\begin{array}{c}{S}_m=\frac{\underset{i=1}{\overset{L}{\Σ}}{D}_m\left(i\right)}{L}\\ m=a,b,c\end{array}& \backslash *MERGEFORMAT\end{array}---\left(2\right)$

Fault characteristic value two: the arbitrarily correlation coefficient of biphase current, shown in equation below (3):

$\begin{array}{cc}\begin{array}{c}{X}_{mm}=\frac{\underset{i=1}{\overset{L}{\Σ}}\left|(D_m-S_m)(D_n-S_n)\right|}{\sqrt{\left(\underset{i=1}{\overset{L}{\Σ}}{(D_m-S_m)}^2\right)\left(\underset{i=1}{\overset{L}{\Σ}}{(D_n-S_n)}^2\right)}}\\ (m,n=a,b,c;m\≠n)\end{array}& \backslash *MERGEFORMAT\end{array}---\left(3\right)$

Step 4, according to design fault characteristic value carry out fault diagnosis, as shown in table 1, fault diagnosis includes fault detect With two links of fault location.Current phasor relevance function value approximately equal after any two phase reconstructions that and if only and if be 1 When, system is in health status, and fault-free occurs.Otherwise, system detects fault, gives fault alarm.Examine in system In the case of measuring fault, position with current phasor meansigma methods according to the current phasor relevance function value after any two phase reconstructions Fault type.As shown in table 1.If the relevance function X of B phase and C phase_bc≈ 1, and two other relevance function X_ab=1, X_ac =1, X_ab≈X_ac, then fault occurs in A phase, if A phase current meansigma methods S_a＜ 0, then fault location is T1 pipe, if A phase current is put down Average S_a＞ 0, then fault location is T2 pipe, if A phase current meansigma methods S_a=0, then fault location is T1T2 pipe.

Table 1

The present invention can detect any three-phase drive system single tube fault and the open circuit event with the two-tube fault of brachium pontis in real time The situation of barrier, it is possible to be accurately positioned fault power pipe.The present invention is applicable to synchronous motor, asynchronous machine current closed-loop or opens The system of ring control strategy, and the on-line checking of the drive system open-circuit fault of power tubes of 5 phases (heterogeneous) motor is had guidance Meaning.The present invention is be applicable to the system of any employing vector control strategy, it is not necessary to extra voltage sensor；It is also applied for Open-circuit fault of power tubes of inverter diagnosis in three phase electric machine open current loop control system；Accuracy of detection is high, and speed is fast, real-time High.The present invention can detect in converter any single tube or two-tube open fault and secondary failure, robustness the most accurately Good, capacity of resisting disturbance is strong.The fault of the present invention will not be examined by the dynamic processes such as electric motor starting, speed change, impact or anticlimax load Disconnected result produces negative influence；And the program is insensitive to motor internal parameter, noise resisting ability is strong；Realize simple, the present invention Can be embedded in control program as a subprogram, not affect without amendment control program.

As it will be easily appreciated by one skilled in the art that and the foregoing is only presently preferred embodiments of the present invention, not in order to Limit the present invention, all any amendment, equivalent and improvement etc. made within the spirit and principles in the present invention, all should comprise Within protection scope of the present invention.

Claims (2)

1. open-circuit fault of power tubes of inverter real-time detection method in motor driven systems, it is characterised in that comprise the following steps:

Step 1, the width of calculating sliding windowWherein, T_sRepresenting the sampling period of electric current loop, n represents that motor turns Speed, p represents the number of pole-pairs of motor；

Step 2, design three-phase current vector, the data of reconstruct current phasor make its same phase:

First, the sampled point in the cycle is stored in vector I_a,I_b,I_cIn, its dimension is L, in each current sample wink Between k, current phasor I_a,I_b,I_cAbandon a sampled point I of most end_a(1),I_b(1),I_c(1), then residue sampled point is being vowed Amount moves to left one, up-to-date sampled point is added I simultaneously_a,I_b,I_c, it is designated as I_a(L),I_b(L),I_c(L), it is achieved data are real-time Online updating；

Then, in each current sample moment, current phasor is carried out data reconstruction, as shown in formula (1):

$\begin{array}{c}\left\{\begin{array}{c}{D}_a=I_a\\ D_b=\[I_b\[1/3L:L\],I_b\[1:1/3L-1\]\]\\ D_c=\[I_c\[2/3L:L\],I_c\[1:2/3L-1\]\]\end{array}\right.\\ \backslash *MERGEFORMAT\end{array}---\left(1\right)$

In formula, I_b(1/3L:L) represent one section of current sample point, from the beginning of the 1/3L of position, terminate with position L；

Step 3, fault characteristic value extract, and design two characteristic quantity functions for fault diagnosis and location:

Fault characteristic value one: current phasor meansigma methods, shown in equation below (2):

$\begin{array}{c}\underset{m=a,b,c}{S_m=\frac{\underset{i=1}{\overset{L}{\Σ}}{D}_m\left(i\right)}{L}}\\ \backslash *MERGEFORMAT\end{array}---\left(2\right)$

Fault characteristic value two: the arbitrarily correlation coefficient of biphase current, shown in equation below (3):

$\begin{array}{cc}\underset{\left(m,n=a,b,c;m\≠n\right)}{X_{mn}=\frac{\underset{i=1}{\overset{L}{\Σ}}\left|(D_m-S_m)(D_n-S_n)\right|}{\sqrt{\left(\underset{i=1}{\overset{L}{\Σ}}{\left(D_m-S_m\right)}^2\right)\left(\underset{i=1}{\overset{L}{\Σ}}{\left(D_n-S_n\right)}^2\right)}}}& \backslash *MERGEFORMAT\end{array}---\left(3\right).$

2. open-circuit fault of power tubes of inverter real-time detection method in motor driven systems as claimed in claim 1, its feature It is, also includes step 4:

Fault characteristic value according to design carries out fault diagnosis: fault diagnosis includes fault detect and two links of fault location, Current phasor relevance function value approximately equal after any two phase reconstructions that and if only and if when be 1, system is in health State, fault-free occurs；System detects fault, gives fault alarm；In the case of system detects fault, according to arbitrarily Current phasor relevance function value after two phase reconstructions positions fault type with current phasor meansigma methods, then by the two of gained Fault characteristic value detects and positions fault power pipe.