CN106908677A - Parallel IGBT fault of converter diagnostic method - Google Patents

Abstract

The invention discloses a kind of diagnostic method of parallel IGBT fault of converter, first, the three-phase phase voltage of collection inverter output sets up three-phase voltage matrix, obtains quantity of state U_k；Then, collection IGBT conduction voltage drops V_i(k), by V_i(k) and threshold value pressure drop V_ceIt is compared, and comparative result is constituted into IGBT pressure drops Boolean matrix V (k), is drawn with the presence or absence of failure according to V (k)；If there is failure, further compare U_kWith the quantity of state V obtained by V (k)_kIf, it is unequal, it is single branch or branched non-parallel IGBT failure, otherwise it is parallel IGBT simultaneous faults；U_kInput set F；If sampling the U for obtaining for continuous six times_kThe change of value generating state, then by F and failure collection FS_iCompare, failure judgement position.Energy of the invention can quick diagnosis fault of converter.

Description

Parallel IGBT fault of converter diagnostic method

Technical field

The present invention relates to a kind of method of diagnosing inverter trouble, specifically, the method can be used to diagnose parallel IGBT Failure in inverter, the method detects and positions IGBT failures in inverter by IGBT conduction voltage drops and three-phase voltage, from And find and report failure ahead of time, improve stability and security.

Background technology

Inverter is used widely in fields such as industry, electric automobile, bullet trains with its superior performance, but by In long-term work in high temperature, high pressure, the state of high frequency, its core component insulated gate bipolar transistor (Insulated Gate Bipolar Transistor, IGBT) degree of aging is rapid, the potential threat as train safety.The damage of IGBT can increase The work load of other power devices, and then cause even more serious second accident, ultimately cause train operation accident.Although Protection circuit is added in the drive circuit of power device of inverter IGBT, but load disturbance, grid disturbance, spatial electromagnetic are disturbed Deng all protection system being caused to fail.

However, for the inverter of high-power output, frequently with the scheme of parallel IGBT.Many researchs at present are devoted to right The research of fault of converter diagnostic method focuses mostly in common inverter, and it is this special that these methods can not be applicable parallel IGBT Operating mode.Method of the existing research often using data analysis during being diagnosed to fault of converter extracts characteristic value, so not only The hardware cost requirement of system is increased, and delays Diagnostic Time.

The content of the invention

Technical problem solved by the invention is, is asked for the fault diagnosis under parallel IGBT inverter this special operation condition A kind of topic, it is proposed that parallel IGBT fault of converter diagnostic method, can quick diagnosis fault of converter.

The invention provides a kind of diagnostic method of the parallel IGBT fault of converter based on Boolean matrix and conduction voltage drop.

The technical solution adopted in the present invention is：

A kind of diagnostic method of parallel IGBT fault of converter, comprises the following steps：

Step one, the three-phase phase voltage u of continuous acquisition inverter output_iK (), i=a, b, c, k=1,2 ..., k are sampling Number of times, and according to the size of three-phase phase voltage, set up three-phase voltage matrix U (k)=[u_a u_b u_c], wherein, three-phase voltage matrix The binary system obtaining value method of middle each element is：

I.e. when phase voltage is more than 0, the element of relevant position is 1 in phase voltage matrix, otherwise is 0.

U (k) is carried out into decimal system conversion, quantity of state U is obtained_k=(u_cu_bu_a)₂=4u_c+2u_b+u_a；So far the three-phase sampled Phase voltage state can be represented that each state corresponds to independent control signal state and IGBT conductings by a ten's digit Pressure drop state；

Step 2, collection IGBT conduction voltage drops V_i(k), i=1,2,3,4,5,6, a upper and lower bridge arms of phase, b phases are corresponded to respectively Upper and lower bridge arm, the upper and lower bridge arm of c phases；Again by V_i(k) and threshold value pressure drop V_ceIt is compared, and comparative result is constituted into IGBT pressure drops Boolean matrixThe value of matrix element is as follows：

That is V_iK () is more than V_ceWhen, its respective element V in matrix V (k)_iIt is 1, on the contrary respective element is 0,

Seek matrix V (k) the first row row₁With the second row row₂Difference, be designated as D (k)=row₁-row₂=[d₁ d₂ d₃]；It is right It is added after each element takes absolute value in D (k), obtains d=| d₁|+|d₂|+|d₃|(d∈{0,1,2,3})；If d=3, explanation does not have It is faulty；Otherwise, if d ∈ { 0,1,2 }, i.e. it is simultaneously 0 or 1 to have a row in V (k), then illustrate that circuit breaks down, into step Rapid three；

Step 3, by the second rows of V (k) row₂The decimal system is converted to, V is obtained_k=(V₆V₄V₂)₂=4V₆+2V₄+V₂；Compare V_k With U_kIf, V_kWith U_kIt is unequal, then it is single branch or branched non-parallel IGBT failure, further contrast row₂With U (k), element value is not The corresponding bridge arm of equal row is failure bridge arm (row of the 1st, 2 and 3 correspond to a phases bridge arm, b phases bridge arm and c phases bridge arm respectively)；Otherwise It is parallel IGBT simultaneous faults, into step 4；

Step 4, by U_kInput set F, the element in F belongs to { 0,1,2,3,4,5,6,7 }, and the initial value of F is sky；Work as U_k Value there is the change of six next states, by F and failure collection FS_iCompare, failure judgement position；If F=FS_i, then FS is illustrated_iIt is right The IGBT of half bridge arm answered breaks down, and FS1~FS6 corresponds to a upper and lower bridge arms of phase, the upper and lower bridge arm of b phases, the upper and lower bridge of c phases respectively Arm；Failure collection FS_iValue is as follows：

FS₁={ (a b 0)₂| a, b ∈ { 0,1 } }={ 0,2,4,6 }

FS₂={ (a b 1)₂| a, b ∈ { 0,1 } }={ 1,3,5,7 }

FS₃={ (c of a 0)₂| a, c ∈ { 0,1 } }={ 0,1,4,5 }

FS₄={ (c of a 1)₂| a, c ∈ { 0,1 } }={ 2,3,6,7 }

FS₅={ (0 b c)₂| b, c ∈ { 0,1 } }={ 0,1,2,3 }

FS₆={ (1 b c)₂| b, c ∈ { 0,1 } }={ 4,5,6,7 }.

The sampling period is suitably adjusted according to IGBT drive circuit in the step one.The present invention is adopted in simulation process The sample cycle is 1ms.

Threshold value pressure drop V in the step 2_ceIt is set to two times of conduction voltage drop.

Principle of the invention is：

As shown in figure 1, the total three-phase of parallel IGBT inverter, per mutually there is upper and lower two bridge arms, each bridge arm includes two IGBT in parallel, the two IGBT have shunting action to circuit, can so undertake line current higher, higher defeated to improve Go out power.

When there is one to break down in two IGBT of parallel connection, all electric currents of the bridge arm are all held by IGBT in parallel therewith Load.Again IGBT be operated in saturation region, in this region conduction voltage drop gone up within the specific limits with conducting electric current it is linear, because This, when an IGBT breaks down, IGBT conduction voltage drops in parallel can increase therewith therewith, in addition the work of high frequency, high current Make state, IGBT temperature rises sharply, it is same to produce the effect for increasing conduction voltage drop.Therefore, when have in V (k) row simultaneously for 0 or 1, judge that now IGBT failures occurs in inverter.

Parallel IGBT fault of converter diagnoses block diagram as shown in Fig. 2 according to inverter circuit structure, only considering IGBT failures Problem, two classes are divided into by fault of converter：The first kind is parallel IGBT while there is open fault, and Equations of The Second Kind is single branch or branched Non- parallel IGBT failure.Single tube failure can be diagnosed using conduction voltage drop Boolean matrix and the contrast of three-phase voltage matrix；Using event Barrier alignment, carries out parallel IGBT open fault simultaneously.

The beneficial effects of the invention are as follows：

The method adapts to the inverter of parallel IGBT this special operation condition, independently of systematic control algorithm, therefore does not receive System control influence；The method does not carry out the mathematic(al) manipulation of complexity, and algorithm complex and the time for reducing diagnostic method are complicated Degree, so as to reduce the hardware-dependent to fault diagnosis system；According to experimental data, the method can substantially reduce IGBT open circuits Fault diagnosis time delay, improves diagnosis efficiency.

Brief description of the drawings

Fig. 1 is parallel IGBT inverter circuit schematic diagram

Fig. 2 is fault diagnosis block diagram

Fig. 3 is Troubleshooting Flowchart

Specific embodiment

The present invention is described in more detail below in conjunction with the drawings and specific embodiments.

The invention discloses a kind of diagnostic method of parallel IGBT fault of converter, comprise the following steps：

Step one, the three-phase phase voltage u of continuous acquisition inverter output_iK (), i=a, b, c, k=1,2 ..., k are sampling (sampling period is suitably adjusted number of times according to IGBT drive circuit.The present invention is 1ms in the sampling period in simulation process), and According to the size of three-phase phase voltage, three-phase voltage matrix U (k)=[u is set up_a u_b u_c], wherein, each unit in three-phase voltage matrix Element binary system obtaining value method be：

I.e. when phase voltage is more than 0, the element of relevant position is 1 in phase voltage matrix, otherwise is 0.

U (k) is carried out into decimal system conversion, quantity of state U is obtained_k=(u_cu_bu_a)₂=4u_c+2u_b+u_a；So far the three-phase sampled Phase voltage state can be represented that each state corresponds to independent control signal state and IGBT conductings by a ten's digit Pressure drop state；

Step 2, collection IGBT conduction voltage drops V_i(k), i=1,2,3,4,5,6, a upper and lower bridge arms of phase, b phases are corresponded to respectively Upper and lower bridge arm, the upper and lower bridge arm of c phases；Again by V_i(k) and threshold value pressure drop V_ce(being set to two times of conduction voltage drop) is compared, and Comparative result is constituted into IGBT pressure drop Boolean matrixThe value of matrix element is as follows：

That is V_iK () is more than V_ceWhen, its respective element V in matrix V (k)_iIt is 1, on the contrary respective element is 0,

Seek matrix V (k) the first row row₁With the second row row₂Difference, be designated as D (k)=row₁-row₂=[d₁ d₂ d₃]；It is right It is added after each element takes absolute value in D (k), obtains d=| d₁|+|d₂|+|d₃|(d∈{0,1,2,3})；If d=3, explanation does not have It is faulty；Otherwise, if d ∈ { 0,1,2 }, i.e. it is simultaneously 0 or 1 to have a row in V (k), then illustrate that circuit breaks down, into step Rapid three；

Step 3, by the second rows of V (k) row₂The decimal system is converted to, V is obtained_k=(V₆V₄V₂)₂=4V₆+2V₄+V₂；Compare V_k With U_kIf, V_kWith U_kIt is unequal, then it is single branch or branched non-parallel IGBT failure, further contrast row₂With U (k), element value is not The corresponding bridge arm of equal row is failure bridge arm (row of the 1st, 2 and 3 correspond to a phases bridge arm, b phases bridge arm and c phases bridge arm respectively)；Otherwise It is parallel IGBT simultaneous faults, into step 4；

Step 4, by U_kInput set F, the element in F belongs to { 0,1,2,3,4,5,6,7 }, and the initial value of F is sky；Work as U_k Value there is the change of six next states, by F and failure collection FS_iCompare, failure judgement position；If F=FS_i, then FS is illustrated_iIt is right The IGBT of half bridge arm answered breaks down, and FS1~FS6 corresponds to a upper and lower bridge arms of phase, the upper and lower bridge arm of b phases, the upper and lower bridge of c phases respectively Arm；Failure collection FS_iValue is as follows：

FS₁={ (a b 0)₂| a, b ∈ { 0,1 } }={ 0,2,4,6 }

FS₂={ (a b 1)₂| a, b ∈ { 0,1 } }={ 1,3,5,7 }

FS₃={ (c of a 0)₂| a, c ∈ { 0,1 } }={ 0,1,4,5 }

FS₄={ (c of a 1)₂| a, c ∈ { 0,1 } }={ 2,3,6,7 }

FS₅={ (0 b c)₂| b, c ∈ { 0,1 } }={ 0,1,2,3 }

FS₆={ (1 b c)₂| b, c ∈ { 0,1 } }={ 4,5,6,7 }.

The present invention is tested, different fault injection times are respectively provided with, to single IGBT and half-bridge injection failure, Obtain diagnosis delay product as follows：

1 single IGBT diagnosis time delay of table

The half-bridge fault diagnosis time delay of table 2

Additionally, in random time, failure is injected to random IGBT, the synthesis result for finally giving all experiment samples is： Average Delay in Diagnosis is 42.3ms, and Average Accuracy is 97.2%, illustrates the real-time of method for diagnosing faults of the present invention and has Effect property.

Claims (3)

1. a kind of diagnostic method of parallel IGBT fault of converter, it is characterised in that comprise the following steps：

Step one, the three-phase phase voltage u of continuous acquisition inverter output_i(k), i=a, b, c, k=1,2 ..., k are sampling number, And according to the size of three-phase phase voltage, set up three-phase voltage matrix U (k)=[u_a u_b u_c], wherein, it is each in three-phase voltage matrix The binary system obtaining value method of element is：

$u_i=\left\{\begin{array}{cc}0& u_i\left(k\right)\≤0\\ 1& u_i\left(k\right)>0\end{array}\right.,(i=a,b,c);$

U (k) is carried out into decimal system conversion, quantity of state U is obtained_k=(u_cu_bu_a)₂=4u_c+2u_b+u_a；

Step 2, collection IGBT conduction voltage drops V_i(k), i=1,2,3,4,5,6, a upper and lower bridge arms of phase are corresponded to respectively, b phases are upper and lower Bridge arm, the upper and lower bridge arm of c phases；Again by V_i(k) and threshold value pressure drop V_ceIt is compared, and comparative result is constituted into IGBT pressure drop boolean MatrixThe value of matrix element is as follows：

$V_i=\left\{\begin{array}{cc}0& V_i\left(k\right)\≤V_{ce}\\ 1& V_i\left(k\right)>V_{ce}\end{array}\right.,(i=1,2,3,4,5,6)$

Seek matrix V (k) the first row row₁With the second row row₂Difference, be designated as D (k)=row₁-row₂=[d₁ d₂ d₃]；To D (k) In each element take absolute value after be added, obtain d=| d₁|+|d₂|+|d₃|(d∈{0,1,2,3})；If d=3, illustrate without event Barrier；If otherwise d ∈ { 0,1,2 }, then illustrate that circuit breaks down, into step 3；

Step 3, by the second rows of V (k) row₂The decimal system is converted to, V is obtained_k=(V₆V₄V₂)₂=4V₆+2V₄+V₂；Compare V_kWith U_k, If V_kWith U_kIt is unequal, then it is single branch or branched non-parallel IGBT failure, further contrast row₂With U (k), element value is unequal The corresponding bridge arm of row be failure bridge arm；It is otherwise parallel IGBT simultaneous faults, into step 4；

Step 4, by U_kInput set F, the element in F belongs to { 0,1,2,3,4,5,6,7 }, and the initial value of F is sky；If continuous six The secondary U for obtaining that samples_kThe change of value generating state, by F and failure collection FS_iCompare, failure judgement position：If F=FS_i, then Illustrate and FS_iThe IGBT of corresponding half bridge arm breaks down, FS₁~FS₂Correspond to a upper and lower bridge arms of phase respectively, the upper and lower bridge arm of b phases, The upper and lower bridge arm of c phases；Failure collection FS_iValue is as follows：

FS₁={ (a b 0)₂| a, b ∈ { 0,1 } }={ 0,2,4,6 }

FS₂={ (a b 1)₂| a, b ∈ { 0,1 } }={ 1,3,5,7 }

FS₃={ (c of a 0)₂| a, c ∈ { 0,1 } }={ 0,1,4,5 }

FS₄={ (c of a 1)₂| a, c ∈ { 0,1 } }={ 2,3,6,7 }

FS₅={ (0 b c)₂| b, c ∈ { 0,1 } }={ 0,1,2,3 }

FS₆={ (1 b c)₂| b, c ∈ { 0,1 } }={ 4,5,6,7 }.

2. the diagnostic method of parallel IGBT fault of converter according to claim 1, it is characterised in that in the step one Sampling period is adjusted according to IGBT drive circuit.

3. the diagnostic method of parallel IGBT fault of converter according to claim 1, it is characterised in that in the step 2 Threshold value pressure drop V_ceIt is set to two times of conduction voltage drop.