Secondary Fault Diagnosis Method for Aviation Three-Stage Starter / Generator Rotating Rectifier

Abstract

The present invention discloses a secondary fault diagnosis method for a rotating rectifier of an aviation three-stage starter / generator. During the starting phase of an aviation three-stage starter / generator system, if a rotating rectifier fails, the system should shut down immediately. However, during the power generation phase, when a single diode open-circuit fault is detected, the system can operate with a reduced rating and fault tolerance. However, at this time, the rotating rectifier is in an asymmetric operating condition, and secondary faults may still occur. The method of the present invention makes full use of the idle winding terminal voltage and rotor position of the exciter when the system is in the power generation phase, and distinguishes the fault category through the voltage binary fluctuation index and the characteristic voltage ratio; and locates the faulty diode through the characteristic rotor position. The algorithm is simple and can realize online diagnosis of secondary faults of the rotating rectifier.

Description

Technical Field

[0001] The invention belongs to the technical field of motor system fault diagnosis, and in particular relates to a secondary fault diagnosis method for an aviation three-stage starter / generator rotating rectifier. Background Art

[0002] Traditional aircraft use multiple energy systems, which directly leads to bloated internal structures and complex engine accessories, resulting in high aircraft failure rates and poor reliability. In order to optimize the traditional energy management system on aircraft, more-electric aircraft technology came into being. Nowadays, integrated starting / generating technology has become one of the important technologies in the field of more-electric aircraft technology. The three-stage starter / generator has the advantages of high reliability, low maintenance cost and simple power generation technology, which makes it widely used in the integrated starting / generating system. Figure 1 As shown in the figure, the three-stage starter / generator consists of auxiliary exciter, exciter, rotating rectifier and main motor.

[0003] In a three-stage starting / generating system, the exciter provides DC excitation to the main motor excitation winding through a rotating rectifier throughout the entire process. Therefore, the reliable operation of the rotating rectifier is key to ensuring the safety of the entire starting / generating system. However, since the rotating rectifier is located on the rotor side and operates continuously under harsh working conditions, its failure rate is significantly higher than other components of the system. To ensure the safe operation of the system, it is of great significance to perform fault diagnosis on the rotating rectifier. During the starting phase of the aviation three-stage starting / generating system, if a rotating rectifier fails, the system should be shut down immediately. However, in the power generation phase, when a single diode open circuit fault is detected, the system can be operated with a reduced rating and fault tolerance. However, at this time, the rotating rectifier is in an asymmetric operating condition and secondary faults may still occur. Therefore, the present invention is mainly aimed at the secondary fault diagnosis of the three-stage starting / generator rotating rectifier in the power generation phase, including the differentiation of secondary fault types and the positioning of secondary fault diodes.

[0004] Technical comparison with China's patent application CN111983449A "Three-stage starter / generator generation stage rotating rectifier fault detection and location method";

[0005] Patent CN111983449A realizes the primary fault diagnosis and positioning of the rotating rectifier, while the present application realizes the secondary fault diagnosis and positioning of the rotating rectifier when the system is in a derated fault-tolerant operating state. The method proposed in patent CN111983449A cannot solve the problem addressed by the present application.

[0006] Technical comparison with China's patent application CN119199630B "Secondary Fault Diagnosis Method for Rotating Rectifier of Multi-stage Starter Generator";

[0007] Although both patent CN119199630B and the present application use the idle winding terminal voltage of the exciter as the fault characteristic signal, the present application additionally extracts the exciter rotor position as the fault location signal, making the fault diagnosis and location of the present application more accurate than that of patent CN119199630B.

[0008] Patent CN119199630B uses the characteristic voltage ratio R and the interval it is in to diagnose whether the state of the rotating rectifier is "an open circuit fault occurs in another diode in the same bridge arm as the faulty diode" (i.e., a same-bridge secondary open circuit fault), while the present application proposes to diagnose whether a same-bridge secondary open circuit fault occurs in the rotating rectifier by comparing the voltage binary fluctuation index S with a set threshold. The two are essentially different in their diagnostic algorithms.

[0009] Patent CN119199630B reconstructs a voltage sequence and searches for the distribution characteristics of the maximum points by first bisecting the voltage sequence based on the first characteristic voltage, then further trisecting the reconstructed sequence excluding the first characteristic voltage, thus dividing the original voltage sequence into four parts. This application, on the other hand, directly trisectes the original voltage sequence based on the first characteristic voltage, resulting in a simpler voltage sequence reconstruction strategy.

[0010] Patent CN119199630B uses the Q value to locate the faulty diode under the secondary open circuit fault, but the positioning is relatively vague and it does not accurately locate whether a certain diode has a secondary open circuit fault. It only achieves weak positioning of the secondary open circuit fault and cannot locate the secondary short circuit fault. The present application is based on the fault positioning signal extracted from the exciter rotor position, and realizes the positioning of the secondary open circuit and secondary short circuit fault diodes through the interval of the rotor characteristic angle. Compared with patent CN119199630B, the diode positioning of the present application is more accurate and comprehensive. Summary of the Invention

[0011] Regarding the secondary fault diagnosis of a three-stage starter / generator rotating rectifier, the specific technical problems to be solved by the present invention are: for the three-stage starter / generator in a state of derating fault-tolerant operation after a single diode open-circuit fault occurs in the rotating rectifier, online diagnosis of the secondary fault of the rotating rectifier is achieved, including distinguishing the secondary fault type and locating the faulty diode.

[0012] The purpose of this invention is to provide a method for diagnosing secondary faults of an aviation three-stage starter / generator rotating rectifier. The specific scheme is as follows:

[0013] Step 1: Online obtain the exciter idle winding terminal voltage and rotor position signal within one cycle, and calculate the voltage binary fluctuation index to distinguish between the same-bridge secondary open circuit fault and other faults. Other faults include no secondary fault, different-bridge secondary open circuit fault, and secondary short circuit fault:

[0014] Step 2: Obtain the first characteristic voltage value of the idle winding terminal voltage within one cycle and its position in the voltage sequence, thereby obtaining the rotor position corresponding to the first characteristic voltage value, and obtain the second and third characteristic voltage values ​​through voltage sequence reconstruction:

[0015] Step 3: Calculate the characteristic voltage ratio and further determine the fault type:

[0016] Step 4: Combine the primary fault diode position to perform "characteristic rotor position" preprocessing and give the secondary fault diode diagnostic code:

[0017] Step 5: Locate the faulty diode in case of secondary short circuit fault or secondary open circuit fault of rotating rectifier by combining the primary faulty diode position and secondary faulty diode diagnostic code.

[0018] As a further improvement of the present invention, the step 1 is specifically as follows:

[0019] 1.1 Based on the fundamental frequency calculated from the exciter speed, the voltage and position sensor are used to collect the voltage at the idle winding terminal of the exciter within one cycle using a moving window register. and rotor position , recorded as voltage series and the rotor position sequence , where N is the number of sampling points in one cycle;

[0020] 1.2 Processing voltage sequence , calculate the voltage binary fluctuation index , first calculate the voltage binary average sequence :when hour, ;when hour, ;Define voltage binary fluctuation index for: ,in , is the proportionality coefficient, , i=1, 2, …, N;

[0021] 1.3 Comparison Value and setting threshold ,like , it indicates that the rotating rectifier has a secondary open circuit fault with the same bridge; if , it indicates that other faults have occurred in the rotating rectifier. If other faults have occurred in the rotating rectifier, proceed to step 2.

[0022] As a further improvement of the present invention, the step 2 is specifically as follows:

[0023] 2.1 Obtain the first characteristic voltage value through the max function And its voltage series The position in is recorded as M, and thus we get The corresponding rotor position , called the “characteristic rotor position”;

[0024] 2.2 With the help of and M voltage series Reconstruction is divided into three groups and ,sequence and The number of data is indivual, The number of data is , among which for The rounded value is based on the number of data in the sequence and In sequence The position M is:

[0025] ), ), , ) ;

[0026] ), ), , ) ;

[0027] ), ), , ) ;

[0028] in for In addition, if ( ,but ) = );like( ,but ) = ), where ;

[0029] 2.3 Obtained by max function and The maximum value of the sequence, that is, the second characteristic voltage value and the third characteristic voltage value .

[0030] As a further improvement of the present invention, the step 3 is specifically as follows:

[0031] 3.1 Definition of the second characteristic voltage value With the first characteristic voltage value The ratio is the characteristic voltage ratio , and by the formula Calculate and obtain; define the third characteristic voltage value With the first characteristic voltage value The ratio is the characteristic voltage ratio , and by the formula Calculate and obtain.

[0032] 3.2 Comparison 、 Value and setting threshold and .like , it indicates that the rotating rectifier has a secondary short circuit fault; if , it indicates that the rotating rectifier has a secondary open circuit fault; if , it indicates that there is no secondary fault in the rotating rectifier. If the rotating rectifier has a secondary short circuit or a secondary open circuit fault of an alien bridge, proceed to step 4.

[0033] As a further improvement of the present invention, the step 4 is specifically as follows:

[0034] 4.1 Define the upper and lower bridge arm diodes connected to the exciter rotor phase a winding as D1 and D4, the upper and lower bridge arm diodes connected to the exciter rotor phase b winding as D3 and D6, and the upper and lower bridge arm diodes connected to the exciter rotor phase c winding as D5 and D2. Perform preprocessing to obtain the characteristic rotor position after preprocessing .

[0035] 4.2 Combined characteristic rotor position The secondary short circuit fault of the rotating rectifier and the secondary open circuit fault of the different bridge determined in step 3 are given as the secondary fault diode diagnostic code.

[0036] Beneficial effects

[0037] This invention proposes a method for secondary fault diagnosis of a three-stage starter / generator rotating rectifier during the power generation phase using the exciter's idle winding terminal voltage and rotor position. This method has the following advantages: 1) It enables secondary fault diagnosis of the rotating rectifier during derated fault-tolerant operation (where a single diode open-circuit fault has occurred), including fault type determination and secondary fault diode location; 2) it fully utilizes the exciter's idle excitation winding and rotor position signals during the power generation phase; and 3) the data processing and algorithm are concise, facilitating online diagnosis. This method helps improve the reliability of three-stage starter / generator systems and prevents fault propagation and further losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 : Schematic diagram of aviation three-stage starter / generator structure;

[0039] Figure 2 : Flow chart of secondary fault diagnosis of rotating rectifier proposed in the present invention;

[0040] Figure 3 : Schematic diagram of the equivalent circuit of the rotor part of the three-stage starting generator with the diodes D1 and D3 open;

[0041] Figure 4 : The first characteristic, second characteristic and third characteristic voltage values ​​of the idle winding terminal voltage of the exciter;

[0042] Figure 5 : Schematic diagram of the voltage and voltage sequence reconstruction at the idle winding terminal when the D1 and D3 diodes are open circuit faults;

[0043] Figure 6 : Characteristic voltage ratio of the exciter idle winding terminal voltage. DETAILED DESCRIPTION

[0044] The present invention is described in detail below with reference to the accompanying drawings and specific embodiments. This embodiment is implemented based on the technical solution of the present invention, and provides a detailed implementation method and specific operation process, but the protection scope of the present invention is not limited to the following embodiments.

[0045] The present invention is further described with reference to the embodiments and drawings, and includes but is not limited to the following embodiments: In this embodiment, the exciter of the three-stage starter / generator has a three-phase excitation winding structure, and the motor operates at a speed of 400 rpm. Figure 2 The figure shows the flowchart of the secondary fault diagnosis process of the rotating rectifier proposed by the present invention. The following is based on the premise that the upper bridge arm diode D1 connected to the exciter phase a armature winding first has an open circuit fault, and the diode D3 has a secondary open circuit fault as an example (such as Figure 3 As shown), the fault diagnosis method is described, and the specific steps included in the embodiment are as follows:

[0046] Step 1: Online obtain the idle winding terminal voltage and rotor position signal of the exciter within one cycle, and calculate the voltage binary fluctuation index Distinguish between the same bridge secondary open circuit fault and other faults (no secondary fault, different bridge secondary open circuit fault, secondary short circuit fault), as follows:

[0047] 1.1 Based on the fundamental frequency calculated at an exciter speed of 400 rpm, which is 20 Hz and a sampling frequency of 2 kHz, the number of sampling points N for the exciter idle winding terminal voltage and rotor position signal in one cycle is 100. The voltage and position sensors are used to collect the exciter idle winding terminal voltage in one cycle using a moving window register. and rotor position , forming a voltage sequence and the rotor position sequence .

[0048] 1.2 Obtain voltage binary average value sequence by calculation :when hour, ;when hour, Voltage binary fluctuation index ,in , is the proportionality coefficient, , i=1, 2, ..., N. In this embodiment, the calculation can be obtained . Combined with the fault diagnosis criteria table, at this time (said The value of is 2, which is determined according to the actual application object). If other faults occur in the rotating rectifier, proceed to step 2.

[0049] Step 2: Obtain the first characteristic voltage value of the idle winding terminal voltage within one cycle and its position in the voltage sequence, thereby obtaining the rotor position corresponding to the first characteristic voltage value, and obtain the second and third characteristic voltage values ​​through voltage sequence reconstruction, as follows:

[0050] 2.1 Obtain the first characteristic voltage value through the max function (like Figure 4 shown) and its voltage sequence Position M in And thus obtain The corresponding rotor position , .

[0051] 2.2 With the help of and M voltage series Reconstruction is divided into three groups and ,sequence and The number of data is 33. The number of data is If Figure 5 As shown, according to the number of sequence data and In sequence The position M is:

[0052] ), ), , )

[0053] ), ), , )

[0054] ), ), , ) , ),

[0055] 2.3 Obtained by max function and The maximum value of the sequence, that is, the second characteristic voltage value and the third characteristic voltage value (like Figure 4 shown).

[0056] Step 3: Calculate the characteristic voltage ratio and further determine the fault type, as follows:

[0057] 3.1 Calculation of characteristic voltage ratio 、 ,like Figure 6 shown.

[0058] 3.2 Comparison 、 Value and setting threshold and . (Said The value of is 0.3, The value is 0.8, which is determined according to the actual application object).

[0059] In this embodiment, the ratio is calculated 、 .at this time, , , combined with the fault diagnosis criteria table, it is determined that the rotating rectifier has a secondary open circuit fault of the different bridge, then continue to step 4.

[0060] Step 4: Combine the primary fault diode position with the "characteristic rotor position" preprocessing and give the secondary fault diode diagnostic code, as follows:

[0061] 4.1 Given that the primary fault diode is D1, we can obtain , as shown in the following table:

[0062]

[0063] 4.2 Combination The rotating rectifier judged in step 3 has a secondary open circuit fault with an alien bridge, and the secondary fault diode diagnostic code is "3O", as shown in the following table:

[0064]

[0065] Step 5: Locate the secondary faulty diode using the primary faulty diode location and the secondary faulty diode diagnostic code given in step 4, as follows:

[0066] Given that the primary faulty diode is D1 and the secondary faulty diode diagnostic code given in step 4 is "3O," as shown in the table below, it is determined that the rotating rectifier diode D3 has a secondary open circuit fault.

[0067]

[0068] Summarizing steps 1 to 4 above, the fault judgment criteria are shown in the following table:

[0069]

[0070] described The value is 2, which is determined according to the actual application object.

[0071] described The value is 0.3, which is determined according to the actual application object.

[0072] described The value is 0.8, which is determined according to the actual application object.

[0073] Combining the above fault judgment criteria with step 5 will form a complete fault diagnosis criteria table of the present invention.

[0074] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention. Such changes and modifications are intended to fall within the scope of the present invention. The scope of protection claimed in the present invention is defined by the appended claims and their equivalents.

Claims

1. A secondary fault diagnosis method for a three-stage starter / generator rotating rectifier of an aviation vehicle, characterized in that: The specific plan is as follows: Step 1: Online obtain the exciter idle winding terminal voltage and rotor position signal within one cycle, and calculate the voltage binary fluctuation index to distinguish between the same-bridge secondary open circuit fault and other faults. Other faults include no secondary fault, different-bridge secondary open circuit fault, and secondary short circuit fault: The step 1 is specifically as follows: 1.1 Based on the fundamental frequency calculated from the exciter speed, the voltage and position sensor are used to collect the voltage at the idle winding terminal of the exciter within one cycle using a moving window register. and rotor position , recorded as voltage series and the rotor position sequence , where N is the number of sampling points in one cycle; 1.2 Processing voltage sequence , calculate the voltage binary fluctuation index , first calculate the voltage binary average sequence :when hour, ;when hour, ; Definition of voltage binary fluctuation index for: ,in , is the proportionality coefficient, , i=1, 2, …, N; 1.3 Comparison Value and setting threshold ,like , it indicates that the rotating rectifier has a secondary open circuit fault with the same bridge; if , it indicates that other faults have occurred in the rotating rectifier. If other faults have occurred in the rotating rectifier, proceed to step 2; Step 2: Obtain the first characteristic voltage value of the idle winding terminal voltage within one cycle and its position in the voltage sequence, thereby obtaining the rotor position corresponding to the first characteristic voltage value, and obtain the second and third characteristic voltage values ​​through voltage sequence reconstruction: The step 2 is specifically as follows: 2.1 Obtain the first characteristic voltage value through the max function And its voltage series The position in is recorded as M, and thus we get The corresponding rotor position , called the "characteristic rotor position"; 2.2 With the help of and M voltage series Reconstruction is divided into three groups and ,sequence and The number of data is indivual, The number of data is , among which for The rounded value is based on the number of data in the sequence and In sequence The position M is: ), ), , ) ； ), ), , ) ； ), ), , ) ； in for In addition, if ( ,but ) = );like( ,but ) = ), where ; 2.3 Obtained by max function and The maximum value of the sequence, that is, the second characteristic voltage value and the third characteristic voltage value ; Step 3: Calculate the characteristic voltage ratio and further determine the fault type: The step 3 is specifically as follows: 3.1 Definition of the second characteristic voltage value With the first characteristic voltage value The ratio is the characteristic voltage ratio , and by the formula Calculate and obtain; define the third characteristic voltage value With the first characteristic voltage value The ratio is the characteristic voltage ratio , and by the formula Calculation acquisition; 3.2 Comparison 、 Value and setting threshold and ,like , it indicates that the rotating rectifier has a secondary short circuit fault; if , it indicates that the rotating rectifier has a secondary open circuit fault; if , it indicates that there is no secondary fault in the rotating rectifier. If the rotating rectifier has a secondary short circuit or a secondary open circuit fault of an alien bridge, proceed to step 4; Step 4: Combine the primary fault diode position with the "characteristic rotor position" preprocessing and give the secondary fault diode diagnostic code: Step 5: Locate the faulty diode in case of secondary short circuit fault or secondary open circuit fault of rotating rectifier by combining the primary faulty diode position and secondary faulty diode diagnostic code.

2. The secondary fault diagnosis method for an aviation three-stage starter / generator rotating rectifier according to claim 1 is characterized in that: The step 4 is specifically as follows: 4.1 Define the upper and lower bridge arm diodes connected to the exciter rotor phase a winding as D1 and D4, the upper and lower bridge arm diodes connected to the exciter rotor phase b winding as D3 and D6, and the upper and lower bridge arm diodes connected to the exciter rotor phase c winding as D5 and D2. Perform preprocessing to obtain the characteristic rotor position after preprocessing ; 4.2 Combined characteristic rotor position The secondary short circuit fault of the rotating rectifier and the secondary open circuit fault of the different bridge determined in step 3 are given as the secondary fault diode diagnostic code.

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