A dual-line ground power on-off network control method

Abstract

The embodiment of the application discloses a double-wire ground power supply switching network control method, relates to the field of aircraft power supply system design, can enhance the reverse polarity fault detection and processing capability of the system, reduces the risk of short circuit of the system due to reverse polarity error, and reduces the risk of accidents during conversion. Specifically, the positive and negative poles of the ground power supply interface are respectively provided with contactors (contactor + / contactor -), and the safety of the ground power supply when inputting into the power grid can be effectively improved by associated control of the pair of contactors. In particular, the reverse polarity fault detection and processing capability of the system is enhanced, the risk of short circuit of the system due to reverse polarity error is significantly reduced, at the same time, the double-wire control strategy also guarantees the smooth conversion between the power supplies of the power supply system during state conversion, and reduces the risk of accidents during conversion.

Description

Technical Field

[0001] This invention relates to the field of aircraft power system design, specifically to the fields of aircraft ground power control and aircraft power supply state transition control, and particularly to a two-wire ground power grid switching control method. Background Technology

[0002] Aircraft power supply and distribution systems typically employ two implementation methods: single-wire and two-wire. In a single-wire system, the positive terminal of the electrical equipment is connected via a conductor or busbar, while the aircraft's metal casing serves as the negative wire. In a two-wire system, both the positive and negative terminals of the generator and the electrical equipment are connected via conductors or busbars. Currently, DC power grids commonly use a single-wire system where the negative wire is connected to the fuselage. During aircraft operation, power supply status transitions frequently occur. For example, during takeoff, power supply transitions from ground power to onboard power; during landing, power supply transitions from onboard power to ground power. In addition to these normal operating power supply status transitions, the system also requires corresponding transitions in the event of a power supply failure. Currently, domestic systems generally use a single-wire ground power supply switching control method for ground power supply and related power supply status transition control. This method has the following shortcomings: In a single-wire power supply system, the aircraft's metal casing serves as the negative terminal. The single-wire ground power control method, where the contactor is directly connected to the fuselage via the positive and negative input ports of the ground power supply, relies solely on the ground power supply for reverse polarity protection in the event of a reverse connection. The aircraft's electrical system cannot perform reverse polarity protection, posing a significant threat to its safety. While a two-wire ground power control method can reduce the risk of short circuits, it faces several challenges. During ground power grid connection / deactivation, if the positive contactor closes while the negative contactor opens, the aircraft's electrical system may experience a floating ground condition, leading to incorrect voltage measurements and false alarms. Furthermore, during power system switching, a closed positive contactor and an open negative contactor can cause unexpected power flow, damaging the ground power supply and even the aircraft's electrical system.

[0003] Therefore, how to solve the control strategy for the safe commissioning and decommissioning of ground power sources, especially reducing the risk of short circuits in the system due to reverse polarity errors, and ensuring smooth transitions between power sources in the power supply system during state transitions, has become a problem that needs to be studied. Summary of the Invention

[0004] The embodiments of the present invention provide a two-wire ground power grid connection and disconnection control method, which can enhance the system's ability to detect and handle reverse polarity faults, reduce the risk of short circuits caused by reverse polarity errors, and reduce the risk of accidents during switching.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] The system includes: ground power contactor 1 (EPC+), ground power contactor 2 (EPC-), main power contactor 1 (GTB1), main power contactor 2 (GTB2), ground power supply, and control chip; wherein, the positive input terminal of the ground power supply is connected to ground power contactor 1 (EPC+), the negative input terminal of the ground power supply is connected to ground power contactor 2 (EPC-), ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) are simultaneously connected to the control chip, and the control chip is also connected to main power contactor 1 (GTB1) and main power contactor 2 (GTB2);

[0007] Ground power contactor 1 (EPC+) is connected to a 270V DC busbar, such as a power strip; ground power contactor 1 (EPC+) serves as the contactor between the positive input terminal of the ground power supply and the DC busbar, and ground power contactor 2 (EPC-) serves as the contactor between the power ground and the negative input terminal of the ground power supply.

[0008] The states of main power contactor 1 (GTB1) and main power contactor 2 (GTB2) are controlled by GCU (Generator Control Unit); the control software collects the states of main power contactor 1 (GTB1) and main power contactor 2 (GTB2), and then performs connection logic control on EPC+ and EPC-. The control software is installed and runs in an embedded system, and the embedded system is installed on the control chip.

[0009] The method includes: switching the switch state of the ground power supply from "off" to "on", and having the control chip control the positive terminals of ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), and controlling the negative terminals of ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) through the switch of the ground power supply.

[0010] During the process of the control chip performing positive terminal control on ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), the process includes: detecting whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the connection conditions; if the connection conditions are met, the control software first performs positive terminal connection control on ground power contactor 2 (EPC-), and then performs positive terminal connection control on ground power contactor 1 (EPC+) 1 second later. The connection conditions include: simultaneously satisfying the ground power switch state as "on", the main power contactor 1 (GTB1) state as "off", and the main power contactor 2 (GTB2) state as "off".

[0011] During the process of the control chip performing positive terminal control on ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), the process includes: detecting whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the disconnection condition; if the disconnection condition is met, the control software first performs positive terminal disconnection control on ground power contactor 1 (EPC+), and then performs positive terminal disconnection control on ground power contactor 2 (EPC-) 1 second later. The disconnection condition includes: the state of main power contactor 1 (GTB1) is "on" or the state of main power contactor 2 (GTB2) is "on".

[0012] In this embodiment of the invention, contactors (contactor + / contactor -) are respectively provided at the positive and negative terminals of the ground power interface. By controlling this pair of contactors in a coordinated manner, the safety of ground power supply when connected to the power grid can be effectively improved. In particular, the system's ability to detect and handle reverse polarity faults is enhanced, and the risk of short circuits caused by reverse polarity errors is significantly reduced. At the same time, the two-wire control strategy also ensures the smooth transition between power supplies in the power supply system during state transition, reducing the risk of accidents during transition. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the system architecture provided for an embodiment of the present invention. Detailed Implementation

[0015] To enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Embodiments of the present invention will be described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention. Those skilled in the art will understand that, unless specifically stated otherwise, the singular forms “a,” “an,” “the,” and “the” used herein may also include the plural forms. It should be further understood that the term “comprising” as used in the specification of the present invention means the presence of the stated features, integers, steps, operations, elements, and / or components, but does not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof. It should be understood that when we say an element is “connected” or “coupled” to another element, it can be directly connected or coupled to the other element, or there may be intermediate elements. Furthermore, “connected” or “coupled” as used herein can include wireless connections or couplings. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items. It will be understood by those skilled in the art that, unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. It should also be understood that terms such as those defined in general dictionaries should be understood to have the meaning consistent with their meaning in the context of the prior art, and should not be interpreted in an idealized or overly formal sense unless defined as herein.

[0016] This invention provides a two-wire ground power supply grid connection and disconnection control method, which is used in a two-wire ground power supply grid connection and disconnection control system, such as... Figure 1 As shown, the system includes: ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), also referred to as "ground power contactors (contactor + / contactor -)". It also includes main power contactor 1 (GTB1), main power contactor 2 (GTB2), ground power supply, and a control chip. The positive input terminal of the ground power supply is connected to ground power contactor 1 (EPC+), and the negative input terminal is connected to ground power contactor 2 (EPC-). Both ground power contactors 1 (EPC+) and 2 (EPC-) are connected to the control chip, which is also connected to main power contactors 1 (GTB1) and 2 (GTB2). The main power contactors are not controlled by this control strategy; the corresponding software only collects the on / off status of the main power contactors.

[0017] The method includes:

[0018] The switch state of the ground power supply is switched from "off" to "on", and the control chip controls the positive terminals of ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) through the switch of the ground power supply.

[0019] Specifically, ground power contactor 1 (EPC+) is connected to a 270V DC busbar; ground power contactor 1 (EPC+) serves as the contactor between the positive input terminal of the ground power supply and the DC busbar, and ground power contactor 2 (EPC-) serves as the contactor between the power ground and the negative input terminal of the ground power supply.

[0020] The states of main power contactor 1 (GTB1) and main power contactor 2 (GTB2) are controlled by GCU; the control software collects the states of main power contactor 1 (GTB1) and main power contactor 2 (GTB2), and then performs connection logic control on EPC+ and EPC-. The control software is installed and runs in the embedded system, and the embedded system is installed on the control chip.

[0021] The dual-wire ground power control strategy designed in this embodiment has contactors (contactor + / contactor -) at the positive and negative terminals of the ground power interface. By controlling this pair of contactors in a coordinated manner, the safety of ground power supply when connected to the grid can be effectively improved. In particular, it enhances the system's ability to detect and handle reverse polarity faults, significantly reducing the risk of short circuits caused by reverse polarity errors. At the same time, the dual-wire control strategy also ensures smooth power supply transitions between power sources during state transitions, reducing the risk of accidents during transitions.

[0022] In this embodiment, during the positive terminal control of ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) by the control chip, the process includes: detecting whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the connection conditions; if the connection conditions are met, the control software first performs positive terminal connection control on ground power contactor 2 (EPC-), and then performs positive terminal connection control on ground power contactor 1 (EPC+) 1 second later. The connection conditions include: simultaneously satisfying the ground power switch state as "on", the main power contactor 1 (GTB1) state as "off", and the main power contactor 2 (GTB2) state as "off". During the process of the control chip performing positive terminal control on ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), the method further includes: detecting whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the disconnection condition; if the disconnection condition is met, the control software first performs positive terminal disconnection control on ground power contactor 1 (EPC+), and then performs positive terminal disconnection control on ground power contactor 2 (EPC-) after 1 second. The disconnection condition includes: the state of main power contactor 1 (GTB1) is "on" or the state of main power contactor 2 (GTB2) is "on".

[0023] For example, the specific conditions for connecting the ground power contactor (contactor+ / contactor-) include: the ground power switch being in the "on" state, the GTBI state being in the "off" state, and the GTB2 state being in the "off" state. When all three conditions are met simultaneously, the control software controls the contactor to perform ground power grid connection control. First, the ground power contactor (EPC-) is connected to the positive terminal, and 1 second later, the ground power contactor (EPC+) is connected to the positive terminal. The purpose of this is to ensure that the ground power and the aircraft electrical system share a common ground, avoiding a floating ground in the aircraft electrical system, which could cause false alarms in the airborne equipment due to measurement errors.

[0024] Ground power contactor (contactor+ / contactor-) disconnection conditions: When the main power contactor 1 is in the "on" state and the main power contactor 2 is in the "on" state, the control software will disconnect the ground power contactor (contactor+) on the positive end when both conditions are met, and disconnect the ground power contactor (contactor-) on the positive end 1 second later.

[0025] Furthermore, before switching the ground power supply from "off" to "on," a quality check is performed on the ground power supply. This quality check includes at least: reverse polarity fault detection, undervoltage detection, overvoltage detection, and excessive pulsation detection. If at least one of the quality checks fails, the ground power supply is locked in a fault state, and its switch state remains "off." In practical applications, before controlling the ground power supply to connect to the grid, its quality is first checked. The checks include reverse polarity fault detection, undervoltage detection, overvoltage detection, and excessive pulsation detection. If the checks fail, the corresponding fault state is locked, prohibiting external power supply from connecting to the grid, thus ensuring grid safety.

[0026] After the ground power supply is connected to the grid, the control software still needs to monitor its quality. If the ground power supply exhibits any one or a combination of overvoltage, undervoltage, and excessive pulsation, it is considered substandard. In this case, the corresponding fault state should be locked, and the ground power supply should be disconnected from the aircraft's power grid according to the disconnection logic. Additionally, during operation, the control software should monitor the ground power supply current in real time. If an overcurrent occurs, the control software should disconnect the ground power supply contactor based on the inverse delay protection characteristic curve, thus disconnecting the ground power supply from the grid. In the event of a short circuit, the control software should control the ground power supply contactors (EPC+ / EPC-) to immediately execute the disconnection process according to predetermined logic. Besides fault conditions, when the aircraft is preparing for takeoff from ground status, the power supply system needs to perform a normal power supply state transition process, which also requires ground power supply disconnection control. The ground power disconnection control logic is as follows: When GTB1 is in the "on" state and GTB2 is in the "on" state, the control software first disconnects the positive terminal of the ground power contactor (EPC+), and then disconnects the positive terminal of the ground power contactor (EPC-) 1 second later. This can avoid the safety hazards caused by the ground power positive terminal still being connected to the aircraft power supply system.

[0027] Specifically, the on / off signals of main power contactor 1 and main power contactor 2 in the control software are output by other control components. This control software only collects the status of the main power contactors and does not control them. Furthermore, this control method is deeply integrated with the ground power quality detection program, enabling the detection and isolation of faults such as undervoltage, overvoltage, excessive pulsation, and reverse polarity in the ground power supply, improving the safety of ground power supply grid connection. Simultaneously, during system operation, it can monitor ground power supply overcurrent / short circuits and promptly disconnect the ground power supply, improving system safety. Through the dual-wire ground power supply grid connection and disconnection control strategy proposed in this invention, the safety of ground power supply when connected to the grid can be effectively improved, especially enhancing the system's ability to detect and handle reverse polarity faults, significantly reducing the risk of short circuits due to reverse polarity errors. At the same time, the dual-wire control strategy also ensures smooth transitions between power sources in the power supply system during state transitions, reducing the risk of accidents during transitions.

[0028] In summary, the control strategy based on dual-wire control in this embodiment solves the problem that reverse polarity protection at the aircraft inlet cannot be implemented in the single-wire ground power grid connection control strategy, reducing the risk of system short circuit caused by reverse polarity faults. In addition, by reasonably designing the contactor control logic, faults caused by floating ground and other issues during the aircraft power supply conversion process in the dual-wire connection control strategy are avoided, thus improving the safety of the system power supply state conversion process.

[0029] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on its differences from other embodiments. In particular, the device embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments. The above descriptions are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for controlling a ground power on / off network of a double-circuit system, characterized by, The method is used in a dual-wire ground power grid connection and disconnection control system, wherein the system includes: ground power contactor 1 (EPC+), ground power contactor 2 (EPC-), main power contactor 1 (GTB1), main power contactor 2 (GTB2), ground power supply, and control chip; wherein, the positive input terminal of the ground power supply is connected to ground power contactor 1 (EPC+), the negative input terminal of the ground power supply is connected to ground power contactor 2 (EPC-), ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) are simultaneously connected to the control chip, and the control chip is also connected to main power contactor 1 (GTB1) and main power contactor 2 (GTB2). The method includes: The switch state of the ground power supply is switched from "off" to "on", and the control chip controls the positive terminals of ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) through the switch of the ground power supply.

2. The method of claim 1, wherein, Ground power contactor 1 (EPC+) is connected to a 270V DC busbar; Ground power contactor 1 (EPC+) serves as the contactor between the positive input terminal of the ground power supply and the DC busbar, while ground power contactor 2 (EPC-) serves as the contactor between the power ground and the negative input terminal of the ground power supply.

3. The method of claim 1, wherein, The states of main power contactor 1 (GTB1) and main power contactor 2 (GTB2) are controlled by the GCU; The control software collects the status of main power contactor 1 (GTB1) and main power contactor 2 (GTB2), and then performs connection logic control on power contactor 1 (EPC+) and ground power contactor 2 (EPC-). The control software is installed and runs in an embedded system, which is installed on the control chip.

4. The method according to any one of claims 1 to 3, characterized in that, During the process of the control chip performing positive terminal control on ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), the following is included: Check whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the connection conditions; If the connection conditions are met, the control software first controls the positive terminal connection of ground power contactor 2 (EPC-), and then controls the positive terminal connection of ground power contactor 1 (EPC+) 1 second later.

5. The method of claim 4, wherein, The connection conditions include: simultaneously satisfying the following conditions: the ground power switch is in the "on" state, the main power contactor 1 (GTB1) is in the "off" state, and the main power contactor 2 (GTB2) is in the "off" state.

6. The method according to any one of claims 1-3, characterized in that, During the process of the control chip performing positive terminal control on ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-), the following is included: Check whether ground power contactor 1 (EPC+) and ground power contactor 2 (EPC-) meet the disconnection conditions; If the disconnection condition is met, the control software first performs positive terminal disconnection control on ground power contactor 1 (EPC+), and then performs positive terminal disconnection control on ground power contactor 2 (EPC-) 1 second later.

7. The method according to claim 6, characterized in that, The disconnection conditions include: The state of main power contactor 1 (GTB1) is "on" or the state of main power contactor 2 (GTB2) is "on".

8. The method according to claim 1, characterized in that, Before switching the ground power supply from "off" to "on", the process also includes: The ground power supply is subjected to quality testing, which includes at least the following: reverse polarity fault detection, undervoltage detection, overvoltage detection, and excessive pulsation detection. If at least one of the quality testing items fails, the ground power supply is locked in a fault state, and the ground power supply is kept in the "off" switch state.

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