Method and device for arc fault detection and protection of aircraft direct current power generation system

Abstract

The invention belongs to the technical field of airplane and power supply system protection, and provides a method and a device for detecting and protecting an arc fault of an airplane direct current power generation system to realize the arc fault detection and protection of an airplane discovery system. The method comprises the following steps: starting an aircraft engine, starting a generator to generate power, closing an aircraft main contactor, performing network casting on the generator, acquiring current Ig + and Ig-signals of positive and negative feeder lines of the generator, outputting a voltage signal Vg signal output by the generator, acquiring the current and voltage signals by a generator arc detection device (3), analyzing the signal by an arc detection processor (34) to identify an arc fault signal, and outputting the arc fault signal. If no arc fault is detected, the state of the main contactor is kept; if an arc fault signal is detected, arc fault occurrence position information and fault types are judged, detection and recognition results are reported to a generator control unit GCU through a communication unit (35), and the GCU executes follow-up protection tripping actions. The method is suitable for different aircraft power generation systems.

Description

Technical Field

[0001] The invention belongs to the technical field of aircraft and power supply system protection, and relates to a method and a device for arc fault detection and protection of an aircraft DC power generation system. Background Art

[0002] In order to meet the high-power electricity demand of aircraft, the current aircraft power supply voltage has been increased from a low voltage of 28V DC to a high voltage of 270V DC. Future aircraft and electric propulsion aircraft have increased the voltage system to more than 1,000 volts. As the voltage level of the onboard electrical system is getting higher and higher, the probability of arc generation has greatly increased, and the harm caused has become more and more serious, especially in high-voltage DC power generation systems. Whether it is the probability of arc generation, the heat released, or the harm caused by the arc, they are all much higher than traditional low-voltage power generation systems.

[0003] In traditional low-voltage power generation systems, electrical faults mainly include overcurrent, short circuit, differential fault, etc., and the impact and harm of arc faults are not prominent. However, as the power of the generator increases, the voltage and current increase, arc faults are a type of electrical fault that occurs frequently in the system, is difficult to detect, and seriously endangers the safety of the system. In particular, the aircraft power generation system, as the source of the entire aircraft power supply, has the characteristics of high voltage and large current. The harm caused by arc faults will affect the power supply and flight safety of the entire aircraft. After an arc fault occurs, it can reach a high temperature of 2000-6000℃ in a few microseconds, or even tens of thousands of degrees Celsius, generating a large amount of heat, accelerating the aging and damage of the generator and the surrounding cable insulation layer, often causing damage to the aircraft generator, resulting in failure of the power generation system and power outage of the aircraft power grid, which seriously affects the flight safety of the aircraft. In order to improve the safety of the aircraft's power generation system, it is necessary to add an arc fault detection device that can identify arc faults and actively protect.

[0004] There have been many flight accidents at home and abroad caused by arc faults in the power generation system that were not protected in time. Currently, traditional aircraft power generation system protection equipment (such as GCU) does not have arc fault detection function and cannot provide arc fault protection for the aircraft power generation system. Summary of the invention

[0005] The purpose of the present invention is to provide a method and device for arc fault detection and protection of an aircraft DC power generation system, so as to realize arc fault detection and protection of an aircraft DC power generation system.

[0006] The technical solution of the present invention:

[0007] A device for arc fault detection and protection of an aircraft DC power generation system, comprising:

[0008] Generator output voltage sensor 31, positive feeder current detection sensor 32, negative feeder current detection sensor 33, arc detection processor 34, data storage unit 35 and communication unit 36;

[0009] The generator output voltage sensor 31, the positive feeder current detection sensor 32, and the negative feeder current detection sensor 33 are connected to the cables of the generator system at the source side, the generator output voltage sensor 31 collects the voltage signal Vg of the generator output main feeder, the positive feeder current detection sensor 32 collects the current signal Ig+ on the generator output positive feeder, and the negative feeder current detection sensor 33 collects the current signal Ig- on the generator output positive feeder; the generator output voltage sensor 31, the positive feeder current detection sensor 32, and the negative feeder current detection sensor 33 are connected to the arc detection processor 34 at the source and secondary sides, and the collected signals are sent to the arc detection processor 34 for detection;

[0010] The communication unit 36 ​​is connected to the arc detection processor 34 at the front stage and connected to the generator control unit GCU2 at the back stage. The detection result of the arc detection processor 34 is reported to the generator control unit GCU2 through the communication unit 36.

[0011] Also includes:

[0012] The data storage unit 35 and the communication unit 36 ​​are connected to the arc detection processor 34. The arc detection processor 34 stores the arc detection results and data in the data storage unit 35 for subsequent data download and analysis during troubleshooting and maintenance.

[0013] After the arc detection processor 34 collects the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg, it uses the built-in arc fault detection algorithm to perform analysis and processing to detect and identify arc faults.

[0014] The arc fault detection algorithm embedded in the arc detection processor 34 is a time-frequency domain characteristic algorithm: it collects the normal state signals of the positive and negative feeder currents Ig+ and Ig- signals of the generator and the output voltage signal Vg of the generator and the data of the abnormal state after the arc occurs, and performs a time domain or frequency domain FFT data analysis method to compare the characteristics of the normal state signals and the arc signals, and then determines whether an arc occurs.

[0015] The arc fault detection algorithm embedded in the arc detection processor 34 uses a deep learning / machine learning / neural network algorithm: it collects the normal state signals of the positive and negative feeder currents Ig+ and Ig- signals of the generator and the output voltage signal Vg of the generator and the data of the abnormal state after an arc occurs, compares the characteristics of the normal state signals and arc signals, conducts model training, and obtains the results.

[0016] The device for arc fault detection and protection of an aircraft DC power generation system of the present invention is an integrated device, which is integrated into a generator control unit GCU as a part of a subcircuit of the generator control unit GCU.

[0017] The device for arc fault detection and protection of an aircraft DC power generation system of the present invention and a generator controller integrally form a generator control unit GCU with an arc detection function.

[0018] A method for arc fault detection and protection of an aircraft DC power generation system, comprising:

[0019] The aircraft engine is started, the generator starts to generate electricity, the aircraft main contactor is closed, the generator is connected to the grid, the positive and negative feeder current Ig+ and Ig- signals of the generator are generated, and the generator output voltage signal Vg is output. The generator arc detection device 3 collects the current and voltage signals, and the arc detection processor 34 performs signal analysis to identify the arc fault signal. If no arc fault is detected, the main contactor state is maintained; if an arc fault signal is detected, the location information of the arc fault and the fault type are determined: the detection and identification results are reported to the generator control unit GCU through the communication unit 35, and the GCU performs subsequent protection tripping actions.

[0020] The arc detection processor 34 detects an arc fault only on the negative feeder, and among the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3, only Ig- has an arc signal, and Ig+ and Vg are zero, then it is determined that a parallel arc fault occurs inside the system generator;

[0021] The type of series-parallel arc fault is determined based on the relationship between Ig- and the rated output current In of the generator. If Ig- is greater than the rated output current In, a parallel arc fault occurs.

[0022] The arc detection processor 34 detects arc faults in both the positive and negative feeders, and the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3 all have arc signals, then it is determined that an arc fault occurs in the external and rear-end lines of the generator;

[0023] The type of series-parallel arc fault is determined based on the relationship between Ig+, Ig- and the rated output current In of the generator. If Ig+=Ig- is greater than the rated output current In, a parallel arc fault occurs; if Ig+=Ig- is less than the rated output current In, a series arc fault occurs.

[0024] Beneficial effects of the present invention:

[0025] The present invention discloses a method and device for arc fault detection and protection of an aircraft DC power generation system. The basic principle is to collect the positive and negative feeder currents and the output voltage of the generator through the current sensors on the DC generator output positive and negative feeders, and enter the arc detection processor for analysis after the signal is processed. When an arc fault occurs inside or outside the generator, the aircraft power generation system arc fault detection device detects the arc fault through the arc detection method pre-placed in the arc detection processor, and then reports the arc fault signal to the generator control unit GCU, and cuts off the main contactor of the power generation system through the GCU, so as to realize the arc fault detection and protection of the aircraft detection system. At the same time, according to the use needs, the aircraft DC power generation system arc fault detection device can be integrated into the generator control unit GCU to form a generator control unit GCU with arc detection function, and realize the arc fault detection and protection of the aircraft detection system on the basis of the original power generation system short circuit fault, overcurrent fault, differential fault and other protection. The method and device are applicable to military aircraft, passenger aircraft, helicopters and the like using DC power generation. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic diagram of the method and device for arc fault detection and protection of a stand-alone aircraft power generation system.

[0027] Figure 2 Schematic diagram of the method and device for arc fault detection and protection of the integrated aircraft power generation system of the present invention.

[0028] Figure 3 Flowchart of the method for arc fault detection and protection of aircraft power generation system of the present invention. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] The present invention provides a device for arc fault detection and protection of a DC aircraft power generation system, such as Figure 1 , 2 As shown, the modules involved include: the original generator 1 of the aircraft itself, the generator control unit GCU2, and the generator arc detection device 3.

[0031] The safe generator arc fault detection device 3 may be an independent device, which is independently installed in the aircraft power generation system, and the communication unit 36 ​​in the generator arc fault detection device 3 is connected to the generator control unit GCU, and is installed close to the generator or the generator control unit GCU.

[0032] The safe generator arc fault detection device 3 can be an integrated device, which is integrated into the generator control unit GCU to form a generator control unit GCU with an arc detection function. On the basis of the existing short circuit, overcurrent and differential protection of the GCU, the detection and protection of arc faults in the DC power generation system are realized.

[0033] The generator arc fault detection device 3, the generator output voltage sensor 31, is packaged together with a positive feeder current detection sensor 32, a negative feeder current detection sensor 33, an arc detection processor 34, a data storage unit 35 and a communication unit 36.

[0034] The arc detection processor 34 receives and processes the voltage signal from the generator output voltage sensor 31, and the current signals from the positive feeder current detection sensor 32 and the negative feeder current detection sensor 33, detects and identifies internal or external arc faults of the generator, and stores the arc detection results and data in the data storage unit 35 for subsequent data download and analysis during troubleshooting and maintenance.

[0035] Furthermore,

[0036] The method for arc fault detection and protection of the aircraft power generation system is based on the simultaneous processing and analysis of the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg, and the arc fault detection and identification of the power generation system is performed through the arc detection and identification algorithm in the arc detection processor 34.

[0037] The method for arc fault detection and protection of the aircraft power generation system is based on the simultaneous processing and analysis of the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg. The arc detection and recognition algorithm in the arc detection processor 34 is used to identify the type and location of the arc fault in the generator, including the series-parallel arc fault occurring in the external positive feeder and the rear-end line of the generator, and the series-parallel arc fault occurring inside the generator. The detection and recognition results are reported to the generator control unit GCU through the communication unit 35, and the GCU performs subsequent protection tripping actions.

[0038] Furthermore, the step of determining the location of the arc fault in the method for detecting and protecting the aircraft power generation system arc fault is as follows:

[0039] The aircraft engine starts, the generator starts to generate electricity, the aircraft main contactor is closed, the generator is connected to the grid, the positive and negative feeder current Ig+ and Ig- signals of the generator are generated, the generator output voltage signal Vg signal is output, the generator arc detection device 3 collects the current and voltage signals, the arc detection processor 34 performs signal analysis to identify the arc fault signal, if an arc fault is detected, the main contactor state is maintained. If an arc fault signal is detected, Figure 3 Flowchart of arc fault detection and protection method for aircraft power generation system, to determine the location information of arc fault and the fault type:

[0040] ① Steps for judging the series-parallel arc fault inside the generator

[0041] The arc detection processor 34 detects an arc fault only in the negative feeder. Among the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3, only Ig- has an arc signal, and Ig+ and Vg are zero, then it is determined that a parallel arc fault has occurred inside the system generator.

[0042] The type of series-parallel arc fault is determined based on the relationship between Ig- and the rated output current In of the generator. If Ig- is greater than the rated output current In, a parallel arc fault occurs.

[0043] Through the above steps, the series-parallel arc fault situation inside the generator can be judged, and the detection and identification results can be reported to the generator control unit GCU through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0044] ② Steps for judging the series-parallel arc faults in the external positive feeder and rear-end lines of the generator

[0045] The arc detection processor 34 detects arc faults in both the positive and negative feeders. If the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3 all have arc signals, it is determined that an arc fault has occurred in the external and rear-end lines of the generator.

[0046] The type of series-parallel arc fault is determined based on the relationship between Ig+, Ig- and the rated output current In of the generator. If Ig+=Ig- is greater than the rated output current In, a parallel arc fault occurs; if Ig+=Ig- is less than the rated output current In, a series arc fault occurs.

[0047] Through the above steps, the series-parallel arc fault situation inside the generator can be judged, and the detection and identification results can be reported to the generator control unit GCU through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0048] Embodiment 1 Method and device for detecting and protecting arc faults in a stand-alone aircraft power generation system

[0049] Reference Figure 1 The safety generator arc fault detection device 3 may be an independent device, which is independently installed in the aircraft power generation system, and the communication unit 36 ​​in the generator arc fault detection device 3 is connected to the generator control unit GCU. The installation position is close to the generator or the generator control unit GCU.

[0050] The generator output voltage sensor 31, the positive feeder current detection sensor 32, and the negative feeder current detection sensor 33 in the generator arc fault detection device 3 collect the generator positive and negative feeder current Ig+ and Ig- signals and the generator output voltage signal Vg signal, and send them to the arc detection processor 34.

[0051] The arc detection processor 34 uses the embedded arc fault detection algorithm to analyze and process the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg, and performs arc fault detection and identification (the present invention does not limit the specific arc detection algorithm used), and determines the location of the arc fault and the arc type according to Example 3, and reports the detection results to the generator control unit GCU2 through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0052] The arc detection processor 34 stores the arc fault data in the data storage unit 35 for subsequent data download and analysis during fault detection and maintenance.

[0053] Embodiment 2 Method and device for arc fault detection and protection of integrated aircraft power generation system (a generator control unit GCU with arc detection function)

[0054] Reference Figure 2 The safety generator arc fault detection device 3 can be an integrated device, which is integrated into the generator control unit GCU as a part of the sub-circuit of the generator control unit GCU. Together with the generator controller, it forms a generator control unit GCU with arc detection function.

[0055] The generator output voltage sensor 31, the positive feeder current detection sensor 32, and the negative feeder current detection sensor 33 in the generator arc fault detection device 3 collect the generator positive and negative feeder current Ig+ and Ig- signals and the generator output voltage signal Vg signal, and send them to the arc detection processor 34.

[0056] The arc detection processor 34 uses the embedded arc fault detection algorithm to analyze and process the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg, and performs arc fault detection and identification (the present invention does not limit the specific arc detection algorithm used), and determines the location of the arc fault and the arc type according to Example 3, and reports the detection results to the generator control unit GCU2 through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0057] The arc detection processor 34 stores the arc fault data in the data storage unit 35 for subsequent data download and analysis during fault detection and maintenance.

[0058] Based on the existing short-circuit, overcurrent and differential protection of GCU, the detection and protection of arc faults in DC power generation system are realized.

[0059] Embodiment 3, step of determining arc fault location information and fault type

[0060] Reference Figure 3 The method and device for arc fault detection and protection of an aircraft power generation system described in Examples 1 and 2 can determine whether the arc fault location of the generator is an external or internal arc fault, and whether the arc fault type is a series arc or a parallel arc, that is, determine whether the current arc fault occurs in the positive feeder line and the rear-end line of the generator, or in the generator, and report the arc fault location information to the GCU.

[0061] The aircraft engine starts, the generator starts to generate electricity, the aircraft main contactor is closed, the generator is connected to the grid, the positive and negative feeder current Ig+ and Ig- signals of the generator are generated, the generator output voltage signal Vg signal is output, the generator arc detection device 3 collects the current and voltage signals, the arc detection processor 34 performs signal analysis to identify the arc fault signal, if an arc fault is detected, the main contactor state is maintained. If an arc fault signal is detected, Figure 3 Flowchart of arc fault detection and protection method for aircraft power generation system, to determine the location information of arc fault and the fault type:

[0062] ① Steps for judging the series-parallel arc fault situation inside the generator (combined with Example 1)

[0063] The arc detection processor 34 detects an arc fault only in the negative feeder. Among the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3, only Ig- has an arc signal, and Ig+ and Vg are zero, then it is determined that a parallel arc fault has occurred inside the system generator.

[0064] The type of series-parallel arc fault is determined based on the relationship between Ig- and the rated output current In of the generator. If Ig- is greater than the rated output current In, a parallel arc fault occurs.

[0065] Through the above steps, the series-parallel arc fault situation inside the generator can be judged, and the detection and identification results can be reported to the generator control unit GCU through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0066] ② Steps for judging the series-parallel arc fault situation occurring in the external positive feeder and rear-end line of the generator (combined with Example 2)

[0067] The arc detection processor 34 detects arc faults in both the positive and negative feeders. If the signals Ig+, Ig-, and Vg collected by the generator arc detection device 3 all have arc signals, it is determined that an arc fault has occurred in the external and rear-end lines of the generator.

[0068] The type of series-parallel arc fault is determined based on the relationship between Ig+, Ig- and the rated output current In of the generator. If Ig+=Ig- is greater than the rated output current In, a parallel arc fault occurs; if Ig+=Ig- is less than the rated output current In, a series arc fault occurs.

[0069] Through the above steps, the series-parallel arc fault situation inside the generator can be judged, and the detection and identification results can be reported to the generator control unit GCU through the communication unit 35, and the GCU executes subsequent protection tripping actions.

[0070] The above description is only an overview of the technical solution of the present invention, in order to enable a clearer understanding of the technical means, objectives and other advantages of the present invention and to implement and obtain them according to the contents of the specification.

[0071] The purpose of the present invention is to achieve the beneficial effects:

[0072] 1) It can provide arc fault detection and protection capabilities for aircraft power generation systems, reduce the harm of arc faults to power generation systems, and improve the safety of aircraft power generation systems.

[0073] 2) For aircraft power generation systems that have been installed or are in service, the existing aircraft design and structure cannot be changed. If it is necessary to increase the arc fault detection function of the generator system, an independent aircraft power generation system arc fault detection and protection device can be selected. It can provide arc detection and protection functions for the power generation system without changing the existing design and structure.

[0074] 3) For newly designed aircraft power generation systems, independent or integrated aircraft power generation system arc fault detection and protection methods and devices can be selected according to design requirements to provide arc detection and protection functions for the power generation system.

[0075] The device will not cause structural and overall changes to the aircraft power generation system, will not affect the original functions of the power generation system, occupies a small space, and the devices are all conventional devices, with low cost and easy selection. It can be selected as an independent or integrated type, can adapt to different aircraft power generation systems, increase the arc fault detection and protection function of the aircraft power generation system, can actively detect arc faults, and increase the safety of the aircraft power generation system.

[0076] In addition to being used in DC generators for civil aircraft and helicopters, it can also be promoted and applied to other fields, such as shipboard DC power generation systems, civil DC power generation systems, factory DC power generation systems, photovoltaic DC power generation systems, and other scenarios and fields that require arc fault protection. It can also be used as a reference for single-phase arc detection in AC power generation systems.

[0077] The above is only a specific embodiment of the present invention, and the present invention is described in detail. The unexplained part is a conventional technology. However, the protection scope of the present invention is not limited to this. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed by the present invention should be included in the protection scope of the present invention. The protection scope of the present invention shall be based on the protection scope of the claims.

Claims

1. A device for arc fault detection and protection of aircraft DC power generation system, characterized in that: include: A generator output voltage sensor (31), a positive feeder current detection sensor (32), a negative feeder current detection sensor (33), an arc detection processor (34), a data storage unit (35) and a communication unit (36); The generator output voltage sensor (31), the positive feeder current detection sensor (32), and the negative feeder current detection sensor (33) are connected to the cables of the generator system at the source side; the generator output voltage sensor (31) collects the voltage signal Vg of the generator output main feeder, the positive feeder current detection sensor (32) collects the current signal Ig+ on the generator output positive feeder, and the negative feeder current detection sensor (33) collects the current signal Ig- on the generator output positive feeder; the generator output voltage sensor (31), the positive feeder current detection sensor (32), and the negative feeder current detection sensor (33) are connected to the arc detection processor (34) at the source side and the secondary side, and the collected signals are sent to the arc detection processor (34) for detection; The communication unit (36) is connected to the arc detection processor (34) at the front stage and connected to the generator control unit GCU (2) at the rear stage. The detection result of the arc detection processor (34) is reported to the generator control unit GCU (2) through the communication unit (36).

2. The device for arc fault detection and protection of aircraft DC power generation system according to claim 1, characterized in that: Also includes: The data storage unit (35) and the communication unit (36) are connected to the arc detection processor (34), and the arc detection processor (34) stores arc detection results and data in the data storage unit (35) for subsequent data download and analysis during troubleshooting and maintenance.

3. The device for arc fault detection and protection of aircraft DC power generation system according to claim 1, characterized in that: After the arc detection processor (34) collects the positive and negative feeder current Ig+ and Ig- signals of the generator and the generator output voltage signal Vg, it uses the built-in arc fault detection algorithm to perform analysis and processing to detect and identify the arc fault.

4. The device for arc fault detection and protection of aircraft DC power generation system according to claim 3, characterized in that: The arc fault detection algorithm embedded in the arc detection processor (34) is a time-frequency domain characteristic algorithm: it collects the normal state signals of the positive and negative feeder currents Ig+ and Ig- signals of the generator and the output voltage signal Vg of the generator and the data of the abnormal state after the arc occurs, performs a time domain or frequency domain FFT data analysis method, compares the characteristics of the normal state signal and the arc signal, and then determines whether an arc occurs.

5. The device for arc fault detection and protection of aircraft DC power generation system according to claim 3, characterized in that: The arc fault detection algorithm embedded in the arc detection processor (34) uses a deep learning / machine learning / neural network algorithm: it collects the normal state signals of the positive and negative feeder currents Ig+ and Ig- signals of the generator and the output voltage signal Vg of the generator and the data of the abnormal state after the arc occurs, compares the characteristics of the normal state signals and the arc signals, conducts model training, and obtains the results.

6. The device for arc fault detection and protection of aircraft DC power generation system according to claim 1, characterized in that: The device for arc fault detection and protection of an aircraft DC power generation system of the present invention is an integrated device, which is integrated into a generator control unit GCU as a part of a subcircuit of the generator control unit GCU.

7. The device for arc fault detection and protection of aircraft DC power generation system according to claim 1, characterized in that: The device for arc fault detection and protection of an aircraft DC power generation system of the present invention and a generator controller integrally form a generator control unit GCU with an arc detection function.

8. A method for arc fault detection and protection of an aircraft DC power generation system, characterized in that: include: The aircraft engine is started, the generator starts to generate electricity, the aircraft main contactor is closed, the generator is connected to the grid, the positive and negative feeder current Ig+ and Ig- signals of the generator are generated, and the generator output voltage signal Vg is output. The generator arc detection device (3) collects the current and voltage signals, and the arc detection processor (34) performs signal analysis to identify the arc fault signal. If no arc fault is detected, the main contactor state is maintained; if an arc fault signal is detected, the location information of the arc fault and the fault type are determined: the detection and identification results are reported to the generator control unit GCU through the communication unit (35), and the GCU performs subsequent protection tripping actions.

9. A method for arc fault detection and protection of an aircraft DC power generation system as claimed in claim 8, characterized in that: The arc detection processor (34) detects an arc fault only in the negative feeder, and among the signals Ig+, Ig-, and Vg collected by the generator arc detection device (3), only Ig- has an arc signal, and Ig+ and Vg are zero, then it is determined that a parallel arc fault occurs inside the system generator; The type of series-parallel arc fault is determined based on the relationship between Ig- and the rated output current In of the generator. If Ig- is greater than the rated output current In, a parallel arc fault occurs.

10. The method for arc fault detection and protection of aircraft DC power generation system according to claim 8, characterized in that: The arc detection processor (34) detects arc faults in both the positive and negative feeder lines, and the signals Ig+, Ig-, and Vg collected by the generator arc detection device (3) all have arc signals, and it is determined that an arc fault occurs in the generator external and rear end lines; The type of series-parallel arc fault is determined based on the relationship between Ig+, Ig- and the rated output current In of the generator. If Ig+=Ig- is greater than the rated output current In, a parallel arc fault occurs; if Ig+=Ig- is less than the rated output current In, a series arc fault occurs.

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