CN115081237B - Aircraft power supply system reliability analysis method based on GO method and common cause failure - Google Patents

Abstract

The present invention relates to a reliability analysis method for an aircraft power system based on a GO method and common cause failures, comprising: determining a GO diagram operator type according to the structure of the aircraft power system and the logical relationship between components, connecting operators of different types with signal flows, and establishing a GO diagram model of the aircraft power system; determining common cause failure groups existing in the aircraft power system and common cause failure probabilities of the common cause failure groups according to the working principle, working environment, and historical fault data of the aircraft power system; obtaining the success probability of the common cause failure groups in the aircraft power system, combining the success probabilities of other components in the aircraft power system, and performing quantitative calculation according to the aircraft power system GO diagram model and GO method operation rules to obtain the success probability of the aircraft power system supplying power to airborne electrical equipment when the influence of common cause failures is considered; the present invention can describe the reliability of the aircraft power system more objectively and accurately.

Description

Reliability analysis method of aircraft power system based on GO method and common cause failure

Technical Field

The invention belongs to the technical field of aircraft power supply reliability, and in particular relates to an aircraft power supply system reliability analysis method based on a GO method and common cause failure.

Background Art

As a key redundant system that supplies power to onboard electrical equipment, the reliability of the aircraft power supply system directly affects the aircraft power supply performance and flight safety. Common cause failure is an unavoidable problem in redundant systems. Since the redundant components in the system often have the same structure, assembly method and operating environment, it is easy for two or more components in the system to fail at the same time due to some common cause, posing a hidden danger to flight safety.

In the reliability research of aircraft power supply systems, domestic and foreign scholars mostly conduct modeling analysis on the basis of the independence of failures among components in the system, and have not conducted in-depth research on the common cause failures among component failures in the system. Failure to consider the common cause failures among redundant components in the aircraft power supply system can easily lead to a certain amount of deviation between the reliability analysis indicators and the actual operating conditions.

Summary of the invention

The purpose of the present invention is to provide an aircraft power system reliability analysis method based on the GO method and common cause failures. The analysis method is based on considering the common cause failures between redundant components in the aircraft power system, and proposes an aircraft power system reliability analysis method based on the GO method and common cause failures to analyze the success probability of the aircraft power system supplying power to onboard electrical equipment.

The present invention solves the technical problem by adopting the following technical solutions:

The reliability analysis method of aircraft power system based on GO method and common cause failure includes the following steps:

S1: Determine the GO diagram operator type according to the structure of the aircraft power system and the logical relationship between the components, connect different types of operators with signal flow, and establish the GO diagram model of the aircraft power system;

S2: Determine the common cause failure groups existing in the aircraft power system and their common cause failure probabilities based on the working principle, working environment and historical failure data of the aircraft power system;

S3: Obtain the success probability of the common cause failure group in the aircraft power system, combine it with the success probability of the other components in the aircraft power system, and perform quantitative calculations based on the aircraft power system GO graph model and GO method operation rules to obtain the success probability of the aircraft power system supplying power to the onboard electrical equipment when considering the influence of common cause failures, so as to analyze the impact of common cause failures between components in the common cause failure group on the reliability of the aircraft power system.

Furthermore, there are at least two components in the common cause failure group, and the components have the same structure and assembly features and the same working environment. When the external environment suddenly changes, multiple components have the probability of failing at the same time.

Furthermore, the failure probability λ _m of component m in the common cause failure group is:

λ _m = λ _I + C

Where λ _I represents the independent failure probability of component m in the common cause failure group, and C represents the probability of common cause failure of component m and other components in the common cause failure group.

Furthermore, the probability of common cause failure of k components in the common cause failure group in the aircraft power system is for:

Where M represents the number of components in the common cause failure group, and _αk represents the proportion of failure events of k components due to common causes to the total failure events.

Furthermore, the success probability R _S of the common cause failure group is:

Wherein, R _I represents the success probability of the common cause failure group when common cause failures between components are not considered, R _0,0,…,0 represents the success probability of the common cause failure group when the success probability of the common cause failure components in the common cause failure group is 0, R _1,1,…,1 represents the success probability of the common cause failure group when the success probability of the common cause failure components in the common cause failure group is 1, C _n is the probability of the common cause failure of the nth failure type in the common cause failure group, and N is the total number of common cause failure types in the common cause failure group.

Furthermore, the GO graph model of the aircraft power system includes operators and signal flows, wherein the operators represent different components or logical relationships in the system; and the signal flows represent input and output signals of components in the system and the associations between components.

Furthermore, the aircraft power system includes an integral drive generator, an auxiliary power unit starter generator, a main battery, an auxiliary battery, a bus bar, a static converter, a transformer rectifier and a circuit breaker.

The advantages and positive effects of the present invention are:

The present invention takes into account the common cause failure factors between redundant components in the aircraft power supply system, establishes a GO graph model of the aircraft power supply system, and can calculate the success probability and failure probability of the aircraft power supply system to normally supply power to airborne electrical equipment under the influence of common cause failures between redundant components in the system according to the historical fault data of the aircraft power supply system. This method can reduce the deviation between the reliability analysis index and the actual operating conditions, and can more objectively and accurately describe the reliability of the aircraft power supply system, providing a reference for improving the in-depth maintenance capability of the aircraft power supply system and guiding the actual design and manufacturing.

BRIEF DESCRIPTION OF THE DRAWINGS

The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

FIG1 is a flow chart of a reliability analysis method for an aircraft power system based on the GO method and common cause failures provided by an embodiment of the invention;

FIG2 shows the types and names of GO graph operators provided in an embodiment of the invention;

FIG3 is a schematic diagram of the structure of an aircraft power supply system provided by an embodiment of the invention;

FIG4 is a GO diagram model of an aircraft power supply system provided by an embodiment of the invention;

DETAILED DESCRIPTION

First, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned herein.

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

The aircraft power system reliability analysis method provided in this embodiment based on the GO method and common cause failure specifically includes the following steps:

S1: Determine the GO diagram operator type according to the aircraft power system structure and the logical relationship between components, connect different types of operators with signal flow, and establish the GO diagram model of the aircraft power system;

The aircraft power system mainly consists of control components such as the integral drive generator, auxiliary power unit starter generator, main battery, auxiliary battery, bus bar, static converter, transformer rectifier and circuit breaker; the GO diagram operator type and name are shown in Figure 2: S represents input signal, R represents output signal, and the number represents the operator type;

Taking the B737-800 aircraft as an example, the schematic diagram of the aircraft power system composition structure is shown in Figure 3: According to the different properties of the electrical energy required by the onboard electrical equipment, the aircraft power system can be divided into an AC power system and a DC power system to supply power to the onboard electrical equipment connected to the AC bus and the DC bus. During the flight of the aircraft, the AC power system can supply power to the AC bus through two integral drive generators and the auxiliary power unit starter generator and their respective circuit breakers; the DC power system supplies power to the DC bus through the aircraft generator and three transformer rectifier assemblies. When both the two aircraft integral drive generators and the auxiliary power unit starter generator fail, the aircraft battery assembly and the static converter supply power to the important AC electrical equipment connected to the AC backup bus; the aircraft main battery and the auxiliary battery supply power to the important DC electrical equipment connected to the DC backup bus.

According to the composition structure of the aircraft power system and the logical relationship between the components, the aircraft power system GO diagram is established, as shown in Figure 4: 2 integral drive generators, auxiliary power unit starter generators, main batteries and auxiliary batteries are used as the signal input of the system, and are represented by type 5 operators; transformer rectifiers, circuit breakers, static converters, and busbars are all represented by type 1 operators; the main battery and auxiliary battery are in parallel, and are connected by type 2 operators or gates; the subsystem composed of 2 integral drive generators and auxiliary power unit starter generators and the subsystem composed of 3 transformer rectifiers will fail only when all components fail, and the type 11 operator 3 out of 1 gate connection is used. The signal flow represents the association between operators, and the arrows and the numbers on the arrows represent the signal flow direction and signal flow sequence number respectively. Signal flow 22 represents the probability that the aircraft power system can normally supply power to the onboard electrical equipment when considering the influence of common cause failures.

S2: Based on the working principle, working environment and historical failure data of the aircraft power system, determine the common cause failure groups and their common cause failure probabilities existing between redundant components in the aircraft power system;

The common cause failure mentioned above refers to the simultaneous failure of two or more components in a system due to some common reasons (environment, design and human factors, etc.); one type of common cause failure comes from the external environment of the system, such as changes in external temperature, pressure, collision, lightning strike and other emergencies; another type of common cause failure comes from the failure propagation of internal components of the system, such as the failure of a component in the system causing the failure of other components or causing the failure of all components of the system. The control protection device in the aircraft power supply system can isolate the faulty part from the normal power supply system, mainly considering the common cause failure of the aircraft power supply system caused by the external environment.

In this embodiment, the common cause failure group is a common cause failure group consisting of a main battery and an auxiliary battery, and a common cause failure group consisting of three transformer-rectifiers; the two batteries and the three transformer-rectifiers in the aircraft power system have the same structure and assembly features, and have the same working environment. When the external environment suddenly changes, multiple components may fail at the same time.

The failure probability λ _A of the main battery A and the failure probability λ _B of the auxiliary battery B in the battery common cause failure group satisfy the following formula:

λ _A ＝λ _AI +C _A,B

λ _B =λ _BI + _CA,B

Wherein, λ _AI and λ _BI represent the independent failure probabilities of the main battery A and the auxiliary battery B respectively, and CA _,B represents the probability of common cause failure of the main battery A and the auxiliary battery B.

The failure probabilities λ _X , λ _Y , and λ _Z of the three transformer-rectifiers in the transformer-rectifier common cause failure group satisfy the following formula:

λ _X =λ _XI +C _X,Y +C _X,Z +C _X,Y,Z

λ _Y =λ _YI +C _X,Y +C _Y,Z +C _X,Y,Z

λ _Z =λ _ZI +C _X,Z +C _Y,Z +C _X,Y,Z

Wherein, λ _XI , λ _YI , λ _ZI represent the independent failure probabilities of transformer-rectifier X, transformer-rectifier Y, and transformer-rectifier Z, respectively; _CX,Y , _CX,Z , _CY,Z represent the probabilities of common cause failure between transformer-rectifier X and transformer-rectifier Y, transformer-rectifier X and transformer-rectifier Z, and transformer-rectifier Y and transformer-rectifier Z, respectively; _CX,Y,Z represents the probability of common cause failure between the three transformer-rectifiers;

Then, the probability of common cause failure of k components in a common cause failure group containing M components in the aircraft power system is Satisfies the following formula:

Wherein, λ _m represents the failure probability of common cause failure component m. It should be noted that for a common cause failure group, the failure probabilities of the components within it are all the same, so λ _m is the failure probability of any component in the common cause failure group; α _k represents the proportion of failure events of k components due to common causes to the total failure events, which can be obtained from historical failure data statistics; among them, the total failure events include independent failure of the component itself and common cause failure between components.

S3: Obtain the success probability of the common cause failure group in the aircraft power system, combine it with the success probability of the remaining components in the aircraft power system (the remaining components here refer to the components in the aircraft power system except the common cause failure group), perform quantitative calculation according to the aircraft power system GO graph model and GO method operation rules, and obtain the success probability of the aircraft power system supplying power to the onboard electrical equipment when considering the influence of the common cause failure, so as to analyze the influence of the common cause failure between the components in the common cause failure group on the reliability of the aircraft power system;

In this embodiment, the success probability of the battery common cause failure group is the probability that the main battery A and the auxiliary battery B can normally supply power to important DC power-consuming equipment, and the success probability of the transformer-rectifier common cause failure group is the probability that the transformer-rectifier can convert AC power into DC power.

Specifically, the common cause failure in the battery common cause failure group includes one failure type of "common cause failure of the main battery A and the auxiliary battery B", and the success probability of the battery common cause failure group is Satisfies the following formula:

Where R _AI,BI represents the success probability of the system when the common cause failure of the main battery A and the auxiliary battery B is not considered; R _0,0 represents the success probability of the system when the success probabilities of the main battery A and the auxiliary battery B are both 0, and R _1,1 represents the success probability of the system when the success probabilities of the main battery A and the auxiliary battery B are both 1; C _A,B represents the probability of common cause failure of the main battery A and the auxiliary battery B, which can be obtained from the probability of common cause failure of two components in a common cause failure group containing two components Calculated.

The common cause failures in the transformer-rectifier common cause failure group include four types of failures: "common cause failure of transformer-rectifier X and transformer-rectifier Y", "common cause failure of transformer-rectifier X and transformer-rectifier Z", "common cause failure of transformer-rectifier Y and transformer-rectifier Z", and "common cause failure of transformer-rectifier X, transformer-rectifier Y and transformer-rectifier Z". The success probability of the transformer-rectifier common cause failure group is Satisfies the following formula:

Wherein, R _XI,YI,ZI represents the success probability of the common cause failure group when the common cause failure of transformer rectifiers X, Y and Z is not considered; R _X0,Y0 and R _X1,Y1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X and Y is 0 and the success probability is 1 respectively; R _X0,Z0 and R _X1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X and Z is 0 and the success probability is 1 respectively; R _Y0,Z0 and R _Y1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers Y and Z is 0 and the success probability is 1 respectively; R _X0,Y0,Z0 and R _X1,Y1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X, Y and Z is 0 and the success probability is 1 respectively; C _X,Y represents the probability of common cause failure of transformer rectifiers X and Y, C _X,Z represents the probability of common cause failure of transformer-rectifiers X and Z, C _Y,Z represents the probability of common cause failure of transformer-rectifiers Y and Z, and C _X,Y,Z represents the probability of common cause failure of transformer-rectifiers X, Y and Z. It should be noted that C _X,Y , C _X,Z , C _Y,Z and C _X,Y,Z can all be obtained by formula A;

In this embodiment, R _Si represents the success probability of signal flow i, and R _Cj represents the success probability of operator j. Specifically:

The success probability _RS9 of signal flow 9 satisfies the following formula:

R _S9 =R _AI,BI +C _A,B ·(R _0,0 -R _1,1 );

The success probability _RS12 of signal stream 12 satisfies the following formula:

R _S12 =[1-(1-R _C1 R _C6 )(1-R _C2 R _C7 )(1-R _C3 R _C8 )]R _C12 ;

The success probability _RS14 of the signal flow 14 includes the success probabilities _RS9 and _RS12 of the common signals 9 and 12. The success probability _RS14 of the signal flow 14 satisfies the following formula:

R _S14 =m ₁ R _S9 +m ₂ R _S12 -m ₃ R _S9 R _S12 ;

In the formula: m ₁ = _{RC11 RC13} , m ₂ = 1, m ₃ = _{RC11 RC13} .

The success probability _RS20 of signal flow 20 satisfies the following formula:

R _S20 = [R _{AI, BI} + C _{A, B} · (R _0,0 - R _1,1 )] R _C20 ;

The success probability _RS21 of the signal stream 21 includes the success probabilities _RS9 and _RS12 of the common signals 9 and 12. The success probability _RS21 of the signal stream 21 satisfies the following formula:

R _S21 =n ₁ R _S9 +n ₂ R _S12 -n ₃ R _S9 R _S12 ;

In the formula: n ₁ = _RC20 , n ₂ = _{RS3RC19 ,} n ₃ = n _{2 RC20} .

The probability of success of signal flow 22 _RS22 includes the success probabilities _RS14 and _RS21 of common signals 14 and 21. The first-order terms of the common signal probabilities are used to replace the higher-order terms to correct the common signals. When considering the influence of common cause failures, the success probability _RS22 of the aircraft power system supplying normal power to the onboard electrical equipment satisfies the following formula:

R _S22 ＝m ₁ n ₁ R _S9 +m ₂ n ₂ R _S12 +(m ₁ n ₂ +m ₂ n ₁ +m ₃ n ₃ -m ₁ n ₃ -m ₂ n ₃ -m ₃ n ₁ -m ₃ n ₂ )R _S9 R _S12 .

Substituting the reliability parameters of each component in the system at different time points, we can get the success probability and failure probability curves of the aircraft power supply system supplying normal power to the onboard electrical equipment when considering the influence of common cause failure. The success probability and failure probability curves of the aircraft power supply system are used to analyze the changing trend of the success probability and failure probability of the aircraft power supply system considering common cause failure between redundant components as the flight time increases.

When considering the common cause failure factors between redundant components in the system, the deviation between the reliability analysis indicators and the actual operating conditions can be reduced, and the reliability of the aircraft power system can be described more objectively and accurately, providing a reference for improving the in-depth maintenance capabilities of the aircraft power system and guiding the actual design and manufacturing.

Therefore, the present invention realizes the reliability analysis of the aircraft power system based on the GO method and common cause failures, and meets the reliability analysis requirements of the aircraft power system when considering the influence of common cause failures.

The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims (4)

1. A reliability analysis method for an aircraft power system based on the GO method and common cause failure, characterized in that it comprises the following steps: S1: Determine the GO diagram operator type according to the structure of the aircraft power system and the logical relationship between the components, connect different types of operators with signal flow, and establish the GO diagram model of the aircraft power system; S2: Determine the common cause failure groups existing in the aircraft power system and their common cause failure probabilities based on the working principle, working environment and historical failure data of the aircraft power system; S3: Obtain the success probability of the common cause failure group in the aircraft power system, combine it with the success probability of other components in the aircraft power system, perform quantitative calculation based on the aircraft power system GO graph model and GO method operation rules, and obtain the success probability of the aircraft power system supplying power to the onboard electrical equipment when considering the influence of common cause failures, so as to analyze the influence of common cause failures between components in the common cause failure group on the reliability of the aircraft power system; The common cause failure group is a common cause failure group consisting of a main battery and an auxiliary battery, and a common cause failure group consisting of three transformer rectifiers; the two batteries and the three transformer rectifiers in the aircraft power system have the same structure and assembly features, and have the same working environment. When the external environment suddenly changes, multiple components may fail at the same time. The failure probability λ _A of the main battery A and the failure probability λ _B of the auxiliary battery B in the battery common cause failure group satisfy the following formula: λ _A ＝λ _AI +C _A,B λ _B =λ _BI + _CA,B Where, λ _AI and λ _BI represent the independent failure probabilities of the main battery A and the auxiliary battery B, respectively, and CA _,B represents the probability of common cause failure of the main battery A and the auxiliary battery B; The failure probabilities λ _X , λ _Y , and λ _Z of the three transformer-rectifiers in the transformer-rectifier common cause failure group satisfy the following formula: λ _X =λ _XI +C _X,Y +C _X,Z +C _X,Y,Z λ _Y ＝λ _YI +C _X,Y +C _Y,Z +C _X,Y,Z λ _Z =λ _ZI +C _X,Z +C _Y,Z +C _X,Y,Z Wherein, λ _XI , λ _YI , λ _ZI represent the independent failure probabilities of transformer-rectifier X, transformer-rectifier Y, and transformer-rectifier Z, respectively; _CX,Y , _CX,Z , _CY,Z represent the probabilities of common cause failure between transformer-rectifier X and transformer-rectifier Y, transformer-rectifier X and transformer-rectifier Z, and transformer-rectifier Y and transformer-rectifier Z, respectively; _CX,Y,Z represents the probability of common cause failure between the three transformer-rectifiers; Then, the probability of common cause failure of k components in a common cause failure group containing M components in the aircraft power system is Satisfies the following formula: Where, λ _m represents the failure probability of common cause failure component m. It should be noted that for a common cause failure group, the failure probabilities of the components within it are all the same, so λ _m is the failure probability of any component in the common cause failure group; α _k represents the proportion of failure events of k components due to common causes to the total failure events, which can be obtained from historical failure data statistics; the total failure events include independent failure of the component itself and common cause failure between components; The common cause failure in the battery common cause failure group includes one failure type, "common cause failure of the main battery A and the auxiliary battery B". The success probability of the battery common cause failure group is Satisfies the following formula: Where, R _AI,BI represents the success probability of the system when the common cause failure of the main battery A and the auxiliary battery B is not considered; R _0,0 represents the success probability of the system when the success probabilities of the main battery A and the auxiliary battery B are both 0, and R _1,1 represents the success probability of the system when the success probabilities of the main battery A and the auxiliary battery B are both 1; C _A,B represents the probability of common cause failure of the main battery A and the auxiliary battery B, which can be obtained from the probability of common cause failure of two components in the common cause failure group containing two components Calculated; The common cause failures in the transformer-rectifier common cause failure group include four types of failures: "common cause failure of transformer-rectifier X and transformer-rectifier Y", "common cause failure of transformer-rectifier X and transformer-rectifier Z", "common cause failure of transformer-rectifier Y and transformer-rectifier Z", and "common cause failure of transformer-rectifier X, transformer-rectifier Y and transformer-rectifier Z". The success probability of the transformer-rectifier common cause failure group is Satisfies the following formula: Wherein, R _XI,YI,ZI represents the success probability of the common cause failure group when the common cause failure of transformer rectifiers X, Y and Z is not considered; R _X0,Y0 and R _X1,Y1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X and Y is 0 and the success probability is 1 respectively; R _X0,Z0 and R _X1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X and Z is 0 and the success probability is 1 respectively; R _Y0,Z0 and R _Y1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers Y and Z is 0 and the success probability is 1 respectively; R _X0,Y0,Z0 and R _X1,Y1,Z1 represent the success probability of the common cause failure group when the success probability of transformer rectifiers X, Y and Z is 0 and the success probability is 1 respectively; C _X,Y represents the probability of common cause failure of transformer rectifiers X and Y, C _X,Z represents the probability of common cause failure of transformer-rectifiers X and Z, C _Y,Z represents the probability of common cause failure of transformer-rectifiers Y and Z, and C _X,Y,Z represents the probability of common cause failure of transformer-rectifiers X, Y and Z. It should be noted that C _X,Y , C _X,Z , C _Y,Z and C _X,Y,Z can all be obtained by formula A; Let R _Si represent the success probability of signal flow i, and R _Cj represent the success probability of operator j. Specifically: The success probability _RS9 of signal flow 9 satisfies the following formula: R _S9 =R _AI,BI +C _A,B ·(R _0,0 -R _1,1 ); The success probability _RS12 of signal stream 12 satisfies the following formula: R _S12 =[1-(1-R _C1 R _C6 )(1-R _C2 R _C7 )(1-R _C3 R _C8 )]R _C12 ; The success probability _RS14 of the signal flow 14 includes the success probabilities _RS9 and _RS12 of the common signals 9 and 12. The success probability _RS14 of the signal flow 14 satisfies the following formula: R _S14 =m ₁ R _S9 +m ₂ R _S12 -m ₃ R _S9 R _S12 ; Where: m ₁ = R _C11 R _C13 , m ₂ = 1, m ₃ = R _C11 R _C13 ; The success probability _RS20 of signal flow 20 satisfies the following formula: R _S20 = [R _{AI, BI} + C _{A, B} · (R _0,0 - R _1,1 )] R _C20 ; The success probability _RS21 of the signal stream 21 includes the success probabilities _RS9 and _RS12 of the common signals 9 and 12. The success probability _RS21 of the signal stream 21 satisfies the following formula: R _S21 =n ₁ R _S9 +n ₂ R _S12 -n ₃ R _S9 R _S12 ; Where: n ₁ = _RC20 , n ₃ =n ₂ R _C20 ; The probability of success of signal flow 22 _RS22 includes the success probabilities _RS14 and _RS21 of common signals 14 and 21. The first-order terms of the common signal probabilities are used to replace the higher-order terms to correct the common signals. When considering the influence of common cause failures, the success probability _RS22 of the aircraft power supply system for normal power supply to the onboard electrical equipment satisfies the following formula: R _S22 ＝m ₁ n ₁ R _S9 +m ₂ n ₂ R _S12 +(m ₁ n ₂ +m ₂ n ₁ +m ₃ n ₃ -m ₁ n ₃ -m ₂ n ₃ -m ₃ n ₁ -m ₃ n ₂ )R _S9 R _S12 . 2. According to claim 1, the reliability analysis method of aircraft power supply system based on GO method and common cause failure is characterized in that: there are at least two components in the common cause failure group, and the components have the same structure and assembly characteristics, and have the same working environment. When the external environment suddenly changes, multiple components have the probability of failing at the same time. 3. The reliability analysis method of an aircraft power system based on the GO method and common cause failure according to claim 1 is characterized in that: the GO graph model of the aircraft power system includes operators and signal flows, the operators represent different components or logical relationships in the system; the signal flows represent the input and output signals of the components in the system and the associations between the components. 4. The reliability analysis method of an aircraft power system based on the GO method and common cause failure according to claim 1 is characterized in that the aircraft power system includes an integral drive generator, an auxiliary power unit starter generator, a main battery, an auxiliary battery, a bus bar, a static converter, a transformer rectifier and a circuit breaker.