CN109031177B - Diagnosis method for both inverter current sensor fault and power tube open circuit fault - Google Patents

Diagnosis method for both inverter current sensor fault and power tube open circuit fault Download PDF

Info

Publication number
CN109031177B
CN109031177B CN201810930465.5A CN201810930465A CN109031177B CN 109031177 B CN109031177 B CN 109031177B CN 201810930465 A CN201810930465 A CN 201810930465A CN 109031177 B CN109031177 B CN 109031177B
Authority
CN
China
Prior art keywords
phase
inverter
diagnostic variable
current
fault
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN201810930465.5A
Other languages
Chinese (zh)
Other versions
CN109031177A (en
Inventor
马皓
任伊昵
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Zhejiang University ZJU
Original Assignee
Zhejiang University ZJU
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Zhejiang University ZJU filed Critical Zhejiang University ZJU
Priority to CN201810930465.5A priority Critical patent/CN109031177B/en
Publication of CN109031177A publication Critical patent/CN109031177A/en
Application granted granted Critical
Publication of CN109031177B publication Critical patent/CN109031177B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R35/00—Testing or calibrating of apparatus covered by the other groups of this subclass
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/26—Testing of individual semiconductor devices
    • G01R31/2601—Apparatus or methods therefor
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R31/00—Arrangements for testing electric properties; Arrangements for locating electric faults; Arrangements for electrical testing characterised by what is being tested not provided for elsewhere
    • G01R31/50—Testing of electric apparatus, lines, cables or components for short-circuits, continuity, leakage current or incorrect line connections

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Inverter Devices (AREA)

Abstract

本发明公开了一种兼顾逆变器电流传感器故障和功率管开路故障的诊断方法，包括从逆变器获取用于诊断的信号；计算桥臂间线电压期望值和桥臂间线电压实际值；计算桥臂间线电压偏差值作为第一诊断变量；计算电感电流之和的偏差值作为第二诊断变量；设定第一诊断变量的阈值；设定第二诊断变量的阈值；计算第一诊断变量和第二诊断变量的极性，再根据故障诊断表来综合诊断逆变器电流传感器故障和功率管开路故障；若诊断出某一相的电流传感器发生了故障，进行电流传感器故障容错。本发明提供的诊断方法具有综合性、快速性和鲁棒性，本不需要额外的硬件电路，可适用于不同控制方法的逆变器系统，且采样频率低、计算量小。

Figure 201810930465

The invention discloses a method for diagnosing both the inverter current sensor fault and the power tube open-circuit fault, including obtaining a signal for diagnosis from the inverter; calculating the expected value of the line voltage between the bridge arms and the actual value of the line voltage between the bridge arms; Calculate the line voltage deviation value between the bridge arms as the first diagnostic variable; calculate the deviation value of the sum of the inductor currents as the second diagnostic variable; set the threshold of the first diagnostic variable; set the threshold of the second diagnostic variable; calculate the first diagnostic variable The polarity of the variable and the second diagnostic variable, and then comprehensively diagnose the inverter current sensor fault and the power tube open-circuit fault according to the fault diagnosis table; The diagnosis method provided by the present invention is comprehensive, rapid and robust, does not need additional hardware circuits, can be applied to inverter systems with different control methods, and has low sampling frequency and small calculation amount.

Figure 201810930465

Description

Diagnosis method considering inverter current sensor fault and power tube open-circuit fault
Technical Field
The invention belongs to the technical field of fault diagnosis of power electronic equipment, and particularly relates to a diagnosis method giving consideration to both inverter circuit sensor faults and power tube open-circuit faults.
Background
The reliability of the inverter is very important for the application fields of renewable energy systems, micro-grids, electric transmission systems and the like. In order to meet the requirements of these application fields for safety, cost, and practicality, attention has been paid to the study of inverter fault diagnosis technology in recent years.
The current sensor in the high-power inverter is easy to break down due to the influence of factors such as noise, vibration and aging, and the failure of the sensor can cause the error of the feedback current value, thereby causing the disorder of the whole system. The semiconductor power tube is the component with the highest failure rate in the power electronic converter, and the open-circuit failure is the common failure of the power tube. Therefore, it is necessary to diagnose the current sensor fault and the open circuit fault of the power tube.
Chinese patent publication No. CN107957527A discloses a fault diagnosis method for an inverter power tube based on a single current sensor technology, in which a single current sensor is installed on two branches of an inverter, the total current of the two branches is collected, the single current sensor is sampled at the middle time of two zero voltage vectors in a PWM period, the phase C current ic and the phase a current ia are obtained, and then the three-phase current of a motor is reconstructed according to ia + ib + ic being 0; and calculating a Park current vector by using the reconstructed three-phase current, obtaining a fault diagnosis variable, and judging the position of the power tube with the open-circuit fault according to the value range of the fault diagnosis variable.
Chinese patent publication No. CN104793161A discloses a method for diagnosing a fault of a current sensor of a motor driving system, which uses two current sensors to detect any two-phase current of a three-phase motor, respectively, and samples a phase current detected by a first current sensor and a phase current detected by a second current sensor, where the number of sampling points in a phase current period is N; and calculating the phase current amplitude in one phase current period, and if the phase current amplitude in one phase current period exceeds the phase balance threshold range for a plurality of times, judging that the phase current is unbalanced, and judging that the current sensor has serious or precision fault.
At present, a method for researching fault diagnosis of a current sensor and a method for diagnosing an open-circuit fault of a power tube are not few, however, the diagnosis methods only consider one fault type, and do not consider the fault of the current sensor and the fault of the power tube comprehensively, which can cause misdiagnosis. For example, a current sensor failure may cause a misdiagnosis of the power tube fault diagnosis method. Moreover, the existing diagnostic methods cannot simultaneously satisfy the requirements of reliability, rapidity and practicability of fault diagnosis.
Disclosure of Invention
The invention aims to provide a diagnosis method for considering both the inverter current sensor fault and the power tube open-circuit fault. The diagnosis method provided by the invention can realize the simultaneous diagnosis of the current sensor fault and the power tube open circuit fault, improves the comprehensiveness of fault diagnosis, and has the characteristics of reliability, rapidness and practicability.
The invention provides the following technical scheme:
the current sensor fault refers to the fault that the sensor completely fails.
A diagnosis method for considering both inverter current sensor faults and power tube open-circuit faults comprises the following steps:
(1) obtaining signals for diagnosis from a control system of the inverter, wherein the signals comprise direct current bus voltage at an input end of the inverter, duty ratio of a power switch, current of an output filter inductor and output voltage;
(2) calculating to obtain expected values of line voltages between bridge arms according to the direct-current bus voltage at the input end of the inverter and the duty ratio of the power switch, and calculating to obtain actual values of the line voltages between the bridge arms according to the inductive current and the output voltage of the inverter;
(3) calculating to obtain a deviation value of the line voltage between the bridge arms as a first diagnosis variable according to the expected value of the line voltage between the bridge arms and the actual value of the line voltage between the bridge arms;
(4) calculating a deviation value of the sum of the inductive currents as a second diagnosis variable according to the expected value of the sum of the inductive currents and the inductive current value obtained by sampling of the current sensor;
(5) setting a threshold value of a first diagnostic variable according to the sampling error, the parameter error, the dead zone and the delay time;
(6) setting a threshold value of a second diagnostic variable according to the sampling error of the inductive current;
(7) obtaining the polarity of the first diagnostic variable by comparing the first diagnostic variable obtained in step (3) with the threshold value of the first diagnostic variable obtained in step (5); obtaining the polarity of the second diagnostic variable by comparing the second diagnostic variable obtained in step (4) with the threshold value of the first diagnostic variable obtained in step (6); comprehensively diagnosing the faults of the inverter current sensor and the open-circuit faults of the power tube according to the fault diagnosis table;
(8) if the current sensor of a certain phase is diagnosed to have a fault, a reconstructed value of the current of the fault phase is obtained through the current calculation of the normal phase, and fault tolerance of the current sensor is carried out.
In the step (2), the expected value of the line voltage between the bridge arms
Figure BDA0001766476580000041
The calculation method comprises the following steps:
Figure BDA0001766476580000042
wherein [ n ]]Value, V, representing the nth sampling instantdcIs the inverse ofDC bus voltage at the input of the inverter, dkAnd diThe duty cycles of the power switches of the inverter k-phase and i-phase, respectively, k, i ≠ a, b, c, and k ≠ i, ki ═ ab, bc, ca.
In the step (2), the actual value v of the line voltage between the bridge armski[n]The calculation method comprises the following steps:
Figure BDA0001766476580000043
wherein L iskAnd LiOutput filter inductors i of the inverter phases k and i, respectivelykAnd iiThe inductive currents (i.e. output currents), v, of the k-phase and i-phase of the inverter, respectivelykAnd viOutput voltages of k-phase and i-phase of the inverter, TsIs the sampling period.
In step (3), said first diagnostic variable Δ vki[n]The calculation method comprises the following steps:
Figure BDA0001766476580000044
in step (4), the second diagnostic variable Δ is[n]The calculation method comprises the following steps:
Figure BDA0001766476580000045
wherein ikIs the value of the inductance current sampled by the current sensor,
Figure BDA0001766476580000046
is the sum of the inductance current expected value.
In step (5), the threshold value v of the first diagnostic variableth,ki[n]The setting method comprises the following steps:
(5-1) calculating the maximum calculation error sigmav of the actual values of the line voltages between the arms caused by the sampling error and the parameter errorki[n]：
Figure BDA0001766476580000051
Wherein, σ vk、σviAnd σ ik、σiiAre respectively the output voltage vk、viAnd the inductor current ik、iiMaximum sampling error of σ Lk、σLiRespectively an output filter inductor Lk、LiThe maximum deviation of (d);
(5-2) calculating the maximum calculation error of the expected value of the line voltage between the bridge arms caused by the sampling error
Figure BDA0001766476580000052
Figure BDA0001766476580000053
Wherein, σ VdcFor dc bus voltage V at the input of the inverterdcMaximum sampling error of;
(5-3) calculating the error sigma of the expected value of the line voltage between the bridge arms caused by dead zone and delay timeddAnd σdl：
Figure BDA0001766476580000054
Figure BDA0001766476580000055
Wherein, tddIs the dead time, tdlIs the delay time;
(5-4) setting a threshold value v of the first diagnostic variable based on the above calculation errorth,ki[n]Is composed of
Figure BDA0001766476580000056
α ≧ 1, α is determined based on the sampling error of the system under normal operating conditions.
In step (6), the threshold value i of the second diagnostic variable isthThe setting method comprises the following steps:
ith＝β·σis
wherein β is more than or equal to 1, sigma isIs the maximum calculated error of the actual value of the sum of the inductor currents due to the sampling error, β is determined based on the sampling error of the system under normal operating conditions.
In step (7), the polarity Δ v of the first diagnostic variableki_pol[n]The calculation method comprises the following steps:
Figure BDA0001766476580000061
in step (7), the polarity Δ i of the second diagnostic variables_pol[n]Is calculated by
Figure BDA0001766476580000062
In step (8), a reconstructed value i of the current of the failed phase is calculated from the current of the normal phasek *[n]The method comprises
Figure BDA0001766476580000063
Wherein ii[n]And ir[n]The inductor current sample values for normal phase i and phase r, respectively.
The diagnosis method provided by the invention realizes the function of simultaneously diagnosing the inverter current sensor fault and the power tube open circuit fault based on two diagnosis variables, and is a comprehensive diagnosis method. These two diagnostic variables are: the deviation value of the line voltage between the bridge arms (first diagnostic variable) and the deviation value of the sum of the inductor currents (second diagnostic variable). The polarity of the diagnosis variable is obtained by comparing the diagnosis variable with the threshold value of the diagnosis variable, and then the inverter current sensor fault and the power tube open-circuit fault are comprehensively diagnosed according to the fault diagnosis table.
Compared with the prior art, the invention has the following advantages:
1) the method can diagnose the fault of the current sensor of the inverter and the open-circuit fault of the power tube simultaneously, and integrate the fault diagnosis of different types of devices into a unified diagnosis method, thereby improving the comprehensiveness of the fault diagnosis, avoiding the problem of misdiagnosis of another type of device caused by the fault of one type of device, and improving the reliability of the fault diagnosis;
2) the diagnosis speed is high, the current sensor fault and the power tube open-circuit fault can be quickly diagnosed, and the diagnosis speed can reach one sampling period;
3) the diagnosis method has strong robustness, the diagnosis threshold value contains all diagnosis calculation errors, and misdiagnosis caused by noise interference, sampling errors, element parameter errors, load shedding, dead zones and delay time during normal work can be avoided;
4) the sampling frequency required by diagnosis is low, the calculation amount is small, the burden on software is small, and the diagnosis method has greater advantages in the high-frequency application field such as an inverter system based on SiC and GaN devices;
5) the diagnosis process is irrelevant to the control algorithm, and the diagnosis method is suitable for inverter systems adopting different control methods;
6) the diagnosis method is irrelevant to the working mode of the power converter, and the method is suitable for both an inversion mode and a rectification mode;
7) the signals required by diagnosis can be obtained from the control system of the inverter, an additional hardware circuit is not required to be built, the calculation is simple, the method can be easily applied to inverter systems with different control methods and inverters with energy bidirectional transmission, the cost and the system complexity are prevented from being further increased, and the method has stronger practicability.
Drawings
FIG. 1 is a schematic circuit diagram of a diagnostic method provided by the present invention;
fig. 2 is a schematic diagram of a method for diagnosing open-circuit faults of a current sensor and a power tube in a grid-connected three-phase inverter system according to an embodiment of the present invention;
FIG. 3 is a typical experimental waveform for current sensor fault diagnosis provided by an embodiment of the present invention;
fig. 4 is a typical experimental waveform for diagnosing an open-circuit fault of a power tube according to an embodiment of the present invention.
Detailed Description
In order to more specifically describe the present invention, the diagnostic method of the present invention will be described in detail below with reference to the accompanying drawings and embodiments. The present embodiment is implemented on the premise of the technical solution of the present invention, and a detailed implementation manner and a specific operation process are given, but the scope of the present invention is not limited to the following embodiments.
According to the circuit schematic diagram of the diagnosis method in fig. 1, in the present embodiment, the diagnosis method for considering both the inverter current sensor fault and the power tube open circuit fault in the grid-connected three-phase inverter system is shown in fig. 2, and includes the following steps:
s1, obtaining a signal for diagnosis from a control system of the inverter.
In a three-phase grid-connected inverter, signals for fault diagnosis include: DC bus voltage V of inverter input enddcDuty cycle d of the power switchkThe current of the output filter inductor (i.e. the output line current) ikOutput voltage (i.e. grid side voltage) vk。
S2, calculating to obtain expected values of line voltages between bridge arms according to the direct-current bus voltage at the input end of the inverter and the duty ratio of the power switch, and calculating to obtain actual values of the line voltages between the bridge arms according to the inductive current (namely output line current) and the output voltage (namely network side phase voltage) of the inverter.
Actual value v of line voltage between bridge armski[n]The calculation method of (k, i ≠ a, b, c, and k ≠ i, as follows):
Figure BDA0001766476580000081
wherein L iskAnd LiThe output filter inductances of the inverter phases k and i, respectively (k, i ═ a, b, c, and k ≠ i, hereinafter the same), ikAnd iiThe inductive currents (i.e. output currents), v, of the k-phase and i-phase of the inverter, respectivelykAnd viOutput voltages of k-phase and i-phase of the inverter, TsFor a sampling period, can be etcIn the switching period of the power tube, [ n ]]The value at the nth sampling time is shown below.
For example, the actual value v of the line voltage between the arms of the two phases a and bab[n]The calculation method comprises the following steps:
Figure BDA0001766476580000091
expected value of line voltage between bridge arms
Figure BDA0001766476580000092
Comprises the following steps:
Figure BDA0001766476580000093
wherein, VdcIs the DC bus voltage at the inverter input, dkAnd diThe duty cycles of the power switches of the k-phase and i-phase of the inverter, respectively.
For example, expected line voltage values between bridge arms of a and b phases
Figure BDA0001766476580000094
Comprises the following steps:
Figure BDA0001766476580000095
and S3, calculating to obtain a deviation value of the line voltage between the bridge arms as a first diagnosis variable according to the expected value of the line voltage between the bridge arms and the actual value of the line voltage between the bridge arms.
Line voltage deviation value (i.e., first diagnostic variable) between arms Δ νki[n]Comprises the following steps:
Figure BDA0001766476580000096
for example, the line voltage deviation value (i.e., the first diagnostic variable) Δ ν between the arms for the two phases a, bab[n]Comprises the following steps:
Figure BDA0001766476580000097
and S4, calculating a deviation value of the sum of the inductive currents as a second diagnosis variable according to the expected value of the sum of the inductive currents and the inductive current value obtained by sampling of the current sensor.
Deviation value (i.e., second diagnostic variable) Δ i of the sum of inductor currentss[n]Is composed of
Figure BDA0001766476580000101
Wherein ikIs the value of the inductance current sampled by the current sensor,
Figure BDA0001766476580000102
is the sum of the inductance current expected value. The inverter in the present embodiment is a three-phase three-wire inverter, so
Figure BDA0001766476580000103
Equal to 0.
And S5, setting a threshold value of a line voltage deviation value (namely, a first diagnosis variable) between bridge arms according to the sampling error, the parameter error, the dead zone and the delay time.
The specific process of setting the threshold of the inter-bridge-arm line voltage deviation value (i.e., the first diagnostic variable) is as follows:
s501, calculating the maximum calculation error sigma v of the actual value of the line voltage between the bridge arms caused by the sampling error and the parameter errorki[n]：
Figure BDA0001766476580000104
Wherein, σ vk、σviAnd σ ik、σiiAre respectively the output voltage vk、viAnd the inductor current ik、iiMaximum sampling error of σ Lk、σLiAre respectively a filter inductance Lk、LiThe maximum deviation of (c).
For example, the maximum calculation error σ v of the actual values of the line voltages between the arms of the two phases a and bab[n]Comprises the following steps:
Figure BDA0001766476580000105
s502, calculating the maximum calculation error of expected values of line voltages between bridge arms caused by sampling errors
Figure BDA0001766476580000106
Figure BDA0001766476580000107
Wherein, σ VdcFor dc bus voltage V at the input of the inverterdcThe maximum sampling error.
For example, the maximum calculation error of expected values of line voltages between arms of a and b phases
Figure BDA0001766476580000111
Is composed of
Figure BDA0001766476580000112
S503, calculating the error sigma of the expected value of the line voltage between the bridge arms caused by dead zone and delay timeddAnd σdl：
Figure BDA0001766476580000113
Figure BDA0001766476580000114
Wherein, tddIs the dead time, tdlIs the delay time.
S504, setting a threshold value v of a line voltage deviation value (first diagnosis variable) between bridge arms based on the calculated errorth,ki[n]Is composed of
Figure BDA0001766476580000115
α is more than or equal to 1, in the embodiment, α is 1.
For example, the threshold v of the line voltage deviation value (first diagnostic variable) between the arms of the two phases a and bth,ab[n]Is composed of
Figure BDA0001766476580000116
And S6, setting a threshold value of a deviation value (namely, a second diagnosis variable) of the sum of the inductive currents according to the sampling error of the inductive currents.
The specific process of setting the threshold value of the deviation value (i.e., the second diagnostic variable) of the sum of the inductor currents is:
s601, calculating the calculation error of the actual value of the sum of the inductive currents caused by the sampling error:
σis＝σia+σib+σic
wherein, σ ia,σib,σicIs an inductive current ia，ib，icThe maximum sampling error.
S602, setting a threshold value i of a deviation value (i.e., a second diagnostic variable) of the sum of the inductor currents based on the above calculation errorthIs composed of
ith＝β·σis
β is more than or equal to 1, in the embodiment, β is 7.
S7, obtaining the polarity of the first diagnostic variable by comparing the first diagnostic variable with the threshold value of the first diagnostic variable; obtaining a polarity of the second diagnostic variable by comparing the second diagnostic variable to a threshold of the second diagnostic variable; and comprehensively diagnosing the inverter current sensor fault and the power tube open-circuit fault according to the fault diagnosis table in the table 1.
Wherein the polarity av of the inter-leg line voltage deviation value (i.e. the first diagnostic variable) is obtainedki_pol[n]The method comprises
Figure BDA0001766476580000121
For example, the polarity Δ ν of the inter-arm line voltage deviation value (i.e., the first diagnostic variable) for the two phases a, b is obtainedab_pol[n]The method comprises the following steps: when Δ vab[n]≤-Δvth,ab[n]When, let Δ vab_pol[n]-1; when- Δ vth,ab[n]<Δvab[n]<Δvth,ab[n]When, let Δ vab_pol[n]0; when Δ vab[n]≥Δvth,ab[n]When, let Δ vab_pol[n]＝1。
The polarity Δ i of the deviation value (i.e., the second diagnostic variable) of the sum of the inductor currents is obtaineds_pol[n]The method comprises
Figure BDA0001766476580000122
Based on the polarity of the diagnostic variable, a fault diagnosis table for realizing comprehensive diagnosis of both the inverter current sensor fault and the power tube open circuit fault is shown in table 1.
Table 1 fault diagnosis table for comprehensively diagnosing inverter current sensor fault and power tube open circuit fault
Figure BDA0001766476580000131
According to the fault diagnosis table, the current sensor fault and the power tube open-circuit fault of the three-phase inverter can be comprehensively diagnosed.
For example, if Δ v is calculated at a certain timeab_pol[n]＝-1、Δvbc_pol[n]＝0、Δvca_pol[n]＝1、Δis_pol[n]The current sensor S of phase a is diagnosed as 1aFailure; if a certain time is calculated to have delta vab_pol[n]＝-1、Δvbc_pol[n]＝0、Δvca_pol[n]＝1、Δis_pol[n]When the value is equal to 0, the upper arm power tube T of the a phase is diagnosedapAn open circuit fault occurs.
And S8, if the current sensor of a certain phase is diagnosed to have a fault, calculating a reconstruction value of the current of the fault phase through the current of the normal phase, and carrying out fault tolerance on the current sensor.
When a fault is diagnosed in the k-phase current sensor, a reconstructed value i of the current of the fault phase is calculated from the current of the normal phasek *[n]Is composed of
Figure BDA0001766476580000141
Wherein ii[n]And ir[n]The inductor current sample values for normal phase i and phase r, respectively.
For example, if a failure is diagnosed in the current sensor of the a-phase, the normal phase, i, will be selected from the currents i of the b and c phasesb[n]And ic[n]Calculating the current reconstruction value i of the fault phase aa *[n]：
Figure BDA0001766476580000142
To more clearly describe this example, fig. 3 and 4 show the experimental results under this example. The parameters used in this experiment are shown in table 2.
Table 2 examples experimental parameters
Figure BDA0001766476580000143
As shown in fig. 3, at t1The a-phase current sensor S is triggered at any momentaAnd (4) failure. Before the fault is triggered, the polarity of the diagnostic variable is maintained at Δ vab_pol[n]＝0、Δvbc_pol[n]＝0、Δvca_pol[n]＝0、Δis_pol[n]The fault diagnosis flag is not triggered 0. Current sensor SaAfter the fault occurs, the polarity of the diagnostic variable changes rapidly. When Δ v is observedab_pol[n]＝-1、Δvbc_pol[n]＝0、Δvca_pol[n]＝1、Δis_pol[n]When 1, the current sensor SaIs diagnosed as failing and the current sensor fault diagnosis flag is triggered. The diagnostic time is one sampling period (0.1 ms).
As shown in fig. 4, at t1A-phase upper bridge arm power tube T is triggered at any momentapOpen circuit failure. Before the fault is triggered, the polarity of the diagnostic variable is maintained at Δ vab_pol[n]＝0、Δvbc_pol[n]＝0、Δvca_pol[n]＝0、Δis_pol[n]The fault diagnosis flag is not triggered 0. Power tube TapAfter the fault occurs, the polarity of the diagnostic variable changes rapidly. When Δ v is observedab_pol[n]＝-1、Δvbc_pol[n]＝0、Δvca_pol[n]＝1、Δis_pol[n]When equal to 0, the power tube TapThe power tube fault diagnosis mark is triggered when the open-circuit fault is diagnosed. The diagnostic time is one sampling period (0.1 ms).
The results prove the comprehensiveness, accuracy and rapidity of the diagnosis method provided by the invention.
The embodiments described above are intended to facilitate one of ordinary skill in the art in understanding and using the invention. It will be readily apparent to those skilled in the art that various modifications to the above-described embodiments may be made, and the generic principles defined herein may be applied to other embodiments without the use of inventive faculty. Therefore, the present invention is not limited to the above embodiments, and those skilled in the art should make improvements and modifications to the present invention based on the disclosure of the present invention within the protection scope of the present invention.

Claims (2)

1.一种兼顾逆变器电流传感器故障和功率管开路故障的诊断方法，包括以下步骤：1. A method for diagnosing both the inverter current sensor fault and the power tube open circuit fault, comprising the following steps: (1)从逆变器的控制系统中获取用于诊断的信号，所述信号包括逆变器输入端的直流母线电压、功率开关的占空比、输出滤波电感的电流和输出电压；(1) Obtaining a signal for diagnosis from the control system of the inverter, the signal includes the DC bus voltage at the input end of the inverter, the duty cycle of the power switch, the current and output voltage of the output filter inductor; (2)由逆变器输入端的直流母线电压和功率开关的占空比计算得到桥臂间线电压期望值，由输出滤波电感的电流和输出电压计算得到桥臂间线电压实际值；(2) The expected value of the line voltage between the bridge arms is calculated from the DC bus voltage at the input end of the inverter and the duty cycle of the power switch, and the actual value of the line voltage between the bridge arms is calculated from the current and output voltage of the output filter inductor; 所述的桥臂间线电压期望值
Figure FDA0002295994020000011
的计算方法为：The expected value of the line-to-line voltage between the bridge arms
Figure FDA0002295994020000011
The calculation method is:
Figure FDA0002295994020000012
Figure FDA0002295994020000012
 其中，[n]表示第n次采样时刻的值，Vdc为逆变器输入端的直流母线电压，dk和di分别为逆变器k相和i相的功率开关的占空比，k,i＝a,b,c，且k≠i，ki＝ab,bc,ca；Among them, [n] represents the value at the nth sampling time, V dc is the DC bus voltage at the input of the inverter, d k and d i are the duty cycles of the power switches of the k-phase and i-phase inverters, respectively, k , i=a,b,c, and k≠i, ki=ab,bc,ca; 所述的桥臂间线电压实际值vki[n]的计算方法为：The calculation method of the actual value of the line-to-line voltage between the bridge arms v ki [n] is:
Figure FDA0002295994020000013
Figure FDA0002295994020000013
 其中，Lk和Li分别为逆变器k相和i相的输出滤波电感，ik和ii分别为逆变器k相和i相的电感电流，vk和vi分别为逆变器k相和i相的输出电压，Ts为采样周期；rk和ri分别为逆变器k相和i相的电感ESR；Among them, L k and L i are the output filter inductances of the k-phase and i-phase of the inverter respectively, i k and i i are the inductor currents of the k-phase and i-phase of the inverter, respectively, v k and v i are the inverter output voltage of inverter k-phase and i-phase, T s is the sampling period; rk and ri are the inductance ESR of inverter k-phase and i -phase respectively; (3)由桥臂间线电压期望值和桥臂间线电压实际值计算得到桥臂间线电压偏差值作为第一诊断变量；(3) Calculate the line voltage deviation value between the bridge arms from the expected value of the line voltage between the bridge arms and the actual value of the line voltage between the bridge arms as the first diagnostic variable; 所述的第一诊断变量Δvki[n]的计算方法为：The calculation method of the first diagnostic variable Δv ki [n] is:
Figure FDA0002295994020000021
Figure FDA0002295994020000021
 (4)由电感电流之和期望值和电流传感器采样得到的电感电流值计算得到电感电流之和的偏差值作为第二诊断变量；(4) Calculate the deviation value of the sum of the inductor currents from the expected value of the inductor current sum and the inductor current value sampled by the current sensor as the second diagnostic variable; 所述的第二诊断变量Δis[n]的计算方法为：The calculation method of the second diagnostic variable Δis [n] is:
Figure FDA0002295994020000022
Figure FDA0002295994020000022
 其中，ik为由电流传感器采样得到的电感电流值，
Figure FDA0002295994020000023
为电感电流之和期望值；Among them, i k is the inductor current value sampled by the current sensor,
Figure FDA0002295994020000023
is the expected value of the sum of the inductor currents; (5)根据采样误差、参数误差、死区和延迟时间设定第一诊断变量的阈值；(5) setting the threshold of the first diagnostic variable according to sampling error, parameter error, dead zone and delay time; 所述的第一诊断变量的阈值vth,ki[n]的设定方法为：The method for setting the threshold v th,ki [n] of the first diagnostic variable is: (5-1)计算由采样误差和参数误差引起的桥臂间线电压实际值的最大计算误差σvki[n]：(5-1) Calculate the maximum calculation error σv ki [n] of the actual value of the line voltage between the bridge arms caused by sampling error and parameter error:
Figure FDA0002295994020000024
Figure FDA0002295994020000024
 其中，σvk、σvi和σik、σii分别是输出电压vk、vi和电感电流ik、ii的最大采样误差，σLk、σLi分别是输出滤波电感Lk、Li的最大偏差；rk和ri分别为逆变器k相和i相的电感ESR；Among them, σv k , σv i and σi k , σi i are the maximum sampling errors of the output voltage v k , vi and inductor current i k , i i respectively, σL k , σL i are the output filter inductors L k , L i respectively The maximum deviation of ; r k and ri are the inductance ESR of inverter k-phase and i -phase respectively; (5-2)计算由采样误差引起的桥臂间线电压期望值的最大计算误差
Figure FDA0002295994020000025
(5-2) Calculate the maximum calculation error of the expected value of the line voltage between the bridge arms caused by the sampling error
Figure FDA0002295994020000025
Figure FDA0002295994020000031
Figure FDA0002295994020000031
 其中，σVdc为逆变器输入端直流母线电压Vdc的最大采样误差；Among them, σV dc is the maximum sampling error of the DC bus voltage V dc at the input end of the inverter; (5-3)计算由死区和延迟时间引起的桥臂间线电压期望值的误差σdd和σdl：(5-3) Calculate the errors σ dd and σ dl of the expected line voltage between the bridge arms caused by dead time and delay time:
Figure FDA0002295994020000032
Figure FDA0002295994020000032
Figure FDA0002295994020000033
Figure FDA0002295994020000033
 其中，tdd是死区时间，tdl是延迟时间；Among them, t dd is the dead time, t dl is the delay time; (5-4)基于以上计算误差，设定第一诊断变量的阈值vth,ki[n]为(5-4) Based on the above calculation error, set the threshold v th,ki [n] of the first diagnostic variable as
Figure FDA0002295994020000034
Figure FDA0002295994020000034
 其中α≥1；where α≥1; (6)根据电感电流的采样误差设定第二诊断变量的阈值；(6) setting the threshold value of the second diagnostic variable according to the sampling error of the inductor current; 所述的第二诊断变量的阈值ith的设定方法为：The method for setting the threshold i th of the second diagnostic variable is: ith＝β·σis i th =β· σis 其中，β≥1，σis是由采样误差引起的电感电流之和实际值的最大计算误差；Among them, β≥1, σis is the maximum calculation error of the actual value of the sum of the inductor currents caused by the sampling error; (7)通过比较步骤(3)得到的第一诊断变量和步骤(5)得到的第一诊断变量的阀值，获得第一诊断变量的极性；通过比较步骤(4)得到的第二诊断变量和步骤(6)得到的第二诊断变量的阀值，获得第二诊断变量的的极性；再根据故障诊断表来综合诊断逆变器电流传感器故障和功率管开路故障；(7) By comparing the first diagnostic variable obtained in step (3) with the threshold value of the first diagnostic variable obtained in step (5), the polarity of the first diagnostic variable is obtained; by comparing the second diagnostic variable obtained in step (4) Variables and the threshold of the second diagnostic variable obtained in step (6), to obtain the polarity of the second diagnostic variable; and then comprehensively diagnose the inverter current sensor fault and the power tube open-circuit fault according to the fault diagnosis table; 所述的第一诊断变量的极性△vki_pol[n]的计算方法为：The calculation method of the polarity Δv ki_pol [n] of the first diagnostic variable is:
Figure FDA0002295994020000041
Figure FDA0002295994020000041
 所述的第二诊断变量的极性△is_pol[n]的计算方法为The calculation method of the polarity Δi s_pol [n] of the second diagnostic variable is:
Figure FDA0002295994020000042
Figure FDA0002295994020000042
 其中，Δvki[n]为第一诊断变量，vth,ki[n]为第一诊断变量的阈值，Δis[n]为第二诊断变量，ith为第二诊断变量的阈值；Wherein, Δv ki [n] is the first diagnostic variable, v th,ki [n] is the threshold of the first diagnostic variable, Δis [n] is the second diagnostic variable, and i th is the threshold of the second diagnostic variable; (8)若诊断出某一相的电流传感器发生了故障，则通过正常相的电流计算得到故障相的电流的重构值，进行电流传感器故障容错。(8) If it is diagnosed that the current sensor of a certain phase is faulty, the reconstruction value of the current of the faulty phase is obtained by calculating the current of the normal phase, and the fault tolerance of the current sensor is performed. 2.根据权利要求1所述的兼顾逆变器电流传感器故障和功率管开路故障的诊断方法，其特征在于，在步骤(8)中，由正常相的电流计算故障相的电流的重构值ik *[n]的方法为2 . The method for diagnosing both the inverter current sensor fault and the power tube open-circuit fault according to claim 1 , wherein in step (8), the reconstructed value of the current of the faulty phase is calculated from the current of the normal phase. 3 . The method for i k * [n] is
Figure FDA0002295994020000043
Figure FDA0002295994020000043
 其中，ii[n]和ir[n]分别是正常相相i和相r的电感电流采样值。Among them, i i [n] and i r [n] are the inductor current sampling values of the normal phase phase i and phase r, respectively.
CN201810930465.5A 2018-08-15 2018-08-15 Diagnosis method for both inverter current sensor fault and power tube open circuit fault Active CN109031177B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810930465.5A CN109031177B (en) 2018-08-15 2018-08-15 Diagnosis method for both inverter current sensor fault and power tube open circuit fault

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810930465.5A CN109031177B (en) 2018-08-15 2018-08-15 Diagnosis method for both inverter current sensor fault and power tube open circuit fault

Publications (2)

Publication Number Publication Date
CN109031177A CN109031177A (en) 2018-12-18
CN109031177B true CN109031177B (en) 2020-03-31

Family

ID=64631350

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810930465.5A Active CN109031177B (en) 2018-08-15 2018-08-15 Diagnosis method for both inverter current sensor fault and power tube open circuit fault

Country Status (1)

Country Link
CN (1) CN109031177B (en)

Families Citing this family (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN111751775B (en) * 2019-03-28 2023-03-14 深圳市瑞能实业股份有限公司 Method and device for detecting current sampling failure
CN111766428A (en) * 2019-04-01 2020-10-13 顺丰科技有限公司 Method and device for measuring current of DC bus of inverter
CN110426664B (en) * 2019-08-07 2020-09-29 浙江大学 Comprehensive diagnosis method for open-circuit fault and current sensor fault of three-phase three-wire system inverter power tube with two current sensors
CN110571752B (en) * 2019-08-08 2020-07-28 华中科技大学 A method and system for diagnosing inverter power source drive faults under closed-loop control
CN110794302B (en) * 2019-10-31 2021-08-10 东南大学 Zero drift fault diagnosis method for current sensor of permanent magnet linear motor
CN111190066B (en) * 2020-01-14 2021-01-05 中南大学 Fault diagnosis method for matrix converter motor driving system
CN111884487B (en) * 2020-08-03 2021-10-12 上海电气风电集团股份有限公司 Converter control method and system, wind power system
CN112444759B (en) * 2020-11-10 2021-09-14 武汉大学 Open-circuit fault diagnosis method and system for power switch device of three-phase three-level rectifier
CN112630596B (en) * 2020-12-15 2024-06-11 重庆大学 Comprehensive diagnosis method for open-circuit faults of IGBT device of wind power converter
CN113109688B (en) * 2021-04-19 2022-11-15 东南大学 Thyristor open-circuit fault diagnosis method for excitation system of synchronous phase modulator
CN113311353B (en) * 2021-06-29 2022-03-18 华中科技大学 Detection method of bridge arm open circuit fault of three-phase voltage source driver based on high frequency injection
CN114114062B (en) * 2021-11-05 2024-05-31 郑州轻工业大学 Direct-current bus single-current sensor inverter fault detection device and method
CN117148123A (en) * 2023-10-31 2023-12-01 锦浪科技股份有限公司 Open circuit fault self-checking method, system and storage medium
CN117491934B (en) * 2023-12-29 2024-03-12 锦浪科技股份有限公司 Sensor fault detection method, system and photovoltaic system
CN118068180A (en) * 2024-04-24 2024-05-24 内蒙古电力(集团)有限责任公司内蒙古电力科学研究院分公司 CHB inverter switch fault diagnosis method and device based on voltage sharing prediction

Family Cites Families (13)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991010280A1 (en) * 1989-12-22 1991-07-11 Allied-Signal Inc. A power inverter snubber circuit
CN103441693B (en) * 2013-08-13 2015-07-22 华北电力大学（保定） Grid-connected photovoltaic power generation micro inverter and control method thereof
CN103701394B (en) * 2013-12-30 2016-06-08 哈尔滨工业大学 A kind of online diagnostic method of the open-circuit fault of power tubes of inverter based on the magnitude of current
CN104793161B (en) * 2014-01-17 2017-11-03 联合汽车电子有限公司 Motor driven systems current sensor faults diagnostic method
CN104965148B (en) * 2015-07-20 2017-12-22 华中科技大学 Open-circuit fault of power tubes of inverter real-time detection method in a kind of motor driven systems
CN105974214B (en) * 2016-05-06 2019-01-18 江苏科技大学 A kind of detection device and method of brshless DC motor three-phase windings phase sequence
CN105891659B (en) * 2016-06-06 2019-04-12 安徽大学 A kind of wind electric converter open-circuit fault diagnostic method
CN105891658B (en) * 2016-06-06 2019-04-12 安徽大学 A kind of diagnostic method of open-circuit fault of power tubes of inverter
CN106124914A (en) * 2016-06-23 2016-11-16 华中科技大学 Open-circuit fault of power tubes of inverter real-time detection method in motor driven systems
CN206818788U (en) * 2017-04-18 2017-12-29 威海天力电源有限公司 Current detection circuit
CN107942219B (en) * 2017-10-23 2019-09-10 浙江大学 A kind of open-circuit fault diagnostic method of three-phase four-wire system inverter transistor
CN107957527A (en) * 2017-12-07 2018-04-24 哈尔滨工业大学 A kind of inverter power pipe method for diagnosing faults based on single current sensor technology
CN108169596B (en) * 2017-12-22 2020-08-28 湖南科比特电气技术有限公司 Calibration system of input current channel of photovoltaic inverter and method for calibrating by using calibration system

Also Published As

Publication number Publication date
CN109031177A (en) 2018-12-18

Similar Documents

Publication Publication Date Title
CN109031177B (en) Diagnosis method for both inverter current sensor fault and power tube open circuit fault
CN106019058B (en) A kind of three-phase full-bridge inverter open fault diagnostic method based on phase current analysis
CN110426664B (en) Comprehensive diagnosis method for open-circuit fault and current sensor fault of three-phase three-wire system inverter power tube with two current sensors
EP3171503B1 (en) Cascaded multilevel converter self-test system and self-test method for the same
CN103424648B (en) The detection method of a kind of converter exception and device
CN105629122B (en) The circuit and diagnostic method of a kind of static failure diagnosis of three-phase full-bridge inverter
WO2017083527A1 (en) An on-line diagnostic method for switch faults in power converters
CN106154103B (en) Diagnosis method of switch tube open circuit fault in three-level inverter
Zhang et al. A unified open-circuit-fault diagnosis method for three-level neutral-point-clamped power converters
CN101515764A (en) Current sampling circuit used for frequency converter and sampling method thereof
CN107942219A (en) A kind of open fault diagnostic method of three-phase four-wire system inverter transistor
CN110187204B (en) A method for detecting the state of DC capacitors of neutral point clamped multilevel converters
CN112955758A (en) Method for insulation resistance measurement in an inverter having a multipoint topology and inverter having a multipoint topology
Estima et al. Fast fault detection, isolation and reconfiguration in fault-tolerant permanent magnet synchronous motor drives
CN103941143A (en) Switched reluctance motor power converter main switch short-circuit fault diagnosis method
EP3432461A1 (en) Power conversion device
KR101309287B1 (en) Apparatus and method for a fault diagnosis of direct current terminal voltage sensor of grid connected power transformer and fault-tolerant control
Li et al. Inverter fault diagnosis algorithm based on midpoint voltage deviation polarity and topology reconstruction
TW201947854A (en) Tolerant control system of three-level T-type inverter and tolerant control method thereof
Khaleghi et al. Detection and localization of open-circuit fault in modular multilevel converter
CN108512450B (en) The acquisition methods and system of device for power switching conducting electric current in Z-source inverter
CN105827131B (en) A kind of more level modules in parallel inverters and its startup self-detection method
Chi et al. A current reconstruction scheme for low-cost PMSM drives using shunt resistors
CN111505524B (en) On-line monitoring method of cascade converter and applicable cascade converter
Ren et al. A fast average model-based method for IGBT and current sensor fault diagnosis in grid-tied inverters

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant