Electrical device for protecting power supply device

Abstract

The invention relates to an electrical arrangement (100) for protecting an electrical apparatus intended to be located between an electrical power source (101) and an electrical load (102), the arrangement comprising:-a power contactor (120) comprising two contacts (121, 122) intended to be connected to the electrical power source; -at least two Hall sensors (161, 162) configured to measure the current at the input of the power contactor; -a pre-charging circuit (150) intended to be located between the power source and the power contactor and connected to the electrical load; -a relay (140) configured to connect or disconnect the pre-charge circuit; -pyrotechnic breaking means (130) intended to be connected to the power source and to the power contactor; and-a controller (110) configured to receive measurements of the Hall sensor and to open or close the power contactor and the relay.

Description

Technical Field

[0001] The present invention relates to the field of protection of electrical equipment, and more particularly to the protection of high-voltage DC power systems. Background Art

[0002] Platforms for electric vertical takeoff and landing (eVTOL) aircraft, electric conventional takeoff and landing (eCTOL) aircraft, and small aircraft for short-haul flights (air taxis) employ a new electric propulsion method powered by high-voltage batteries. These high-voltage batteries containing huge amounts of energy usually have built-in electrical protection based on fuses to be able to cut off the line in case of a hard short circuit (i.e., when two short-circuited points are in direct contact with each other). Thus, these fuses make it possible to protect the power supply.

[0003] However, in case of overload or current flowing through a soft short circuit, i.e., when two short-circuited points are connected through an impedance grounding medium, there is a first grey area between the protection provided by the fuse and the protection provided by the power contactor, where the aircraft line is not protected. In case of a very large short-circuit current, there is also a second grey area, which may cause the contactor to float and be damaged, and also limit the current flowing through the fuse, thus delaying its tripping.

[0004] Therefore, the fuses and contactors commonly present in high-voltage power supplies (such as those based on high-voltage batteries) do not always protect the electrical equipment located between the power supply and the load.

[0005] Therefore, there is a need for an electrical protection component that makes it possible to protect the electrical equipment of a power supply system based on high-voltage DC batteries. Summary of the Invention

[0006] The present invention relates to an electrical device for protecting an electrical equipment, which is intended to be located between a power supply and an electrical load, the power supply including a positive terminal and a negative terminal, the device comprising:

[0007] - A power contactor, which includes a first contact intended to be connected to the positive terminal of the power supply and a second contact intended to be connected to the negative terminal of the power supply;

[0008] - At least two Hall effect sensors, which are configured to measure the current flowing between the power supply and the power contactor;

[0009] - A pre-charge circuit, which includes an input terminal intended to be located between the power supply and the power contactor and an output terminal intended to be connected to the electrical load;

[0010] - A relay, which is configured to connect or disconnect the pre-charge circuit;

[0011] - A pyrotechnic electrical disconnect device, which is intended to be connected to the negative terminal of the power supply and the second contact of the power contactor; and

[0012] - A controller, which is configured to receive the current measured by the Hall effect sensor and trigger the opening or closing of the power contactor and the relay.

[0013] The pyrotechnic electrical disconnect device, commonly known as a thermal fuse, is capable of disconnecting the power circuit through a fusing effect at high currents (e.g., currents up to 5 kA) or through the mechanical disconnection effect of a pyrotechnic actuator (present in the thermal fuse) at low currents.

[0014] Thus, due to the device of the present invention, combining the thermal fuse with the power contactor enables the distribution line to be disconnected once a short circuit or overload occurs.

[0015] Specifically, in the case of an overload (e.g., when the current measured by the Hall effect sensor is between the nominal current and 1 kA), the fault current can be obtained through the current measurement value derived from the Hall effect sensor, and the controller can command the disconnection of the contactor. In the case of a short circuit (e.g., when the current measured by the Hall effect sensor is between 1 kA and 5 kA), the thermal fuse will disconnect to protect the electrical equipment.

[0016] According to a specific feature of the present invention, the device further includes a fuse, which is intended to be connected to the positive terminal of the power supply and the first contact of the power contactor.

[0017] This fuse enables additional protection for the electrical equipment in the case of a severe short circuit.

[0018] According to another specific feature of the present invention, the device further includes a magnetic probe, which is located between the pyrotechnic electrical disconnect device and the second contact of the power contactor, and is configured to detect a short circuit and trigger the disconnection of the pyrotechnic electrical disconnect device.

[0019] Another subject of the present invention is a high-voltage DC distribution board, which includes the protection device according to the present invention and an electrical circuit for energizing an electrical load.

[0020] Another subject of the present invention is a method for controlling the electrical protection device according to the present invention, the method including:

[0021] - Closing the relay to connect the pre-charge circuit to the electrical load;

[0022] - Closing the power contactor;

[0023] - Opening the relay to allow current to flow from the power supply to the electrical load; and

[0024] - The current flowing through the protection device is measured by Hall effect sensors and compared with two predetermined thresholds. If the measured current is between these two predetermined thresholds, the power contactor is disconnected; or, if the measured current is greater than these two predetermined thresholds, the pyrotechnic electrical disconnection device is disconnected.

[0025] According to a specific feature of the invention, the measurement of the current flowing through the protection device is also performed by a magnetic probe.

[0026] Another subject of the invention is an aircraft comprising an electrical protection device according to the invention and / or a distribution board according to the invention. Description of the Drawings

[0027] Other features and advantages of the invention will become clearer from the following description and with reference to the drawings, which illustrate exemplary embodiments of the invention, but are not limited thereto.

[0028] Figure 1 Figure 1 Schematically and partially shows an electrical protection device according to an embodiment of the invention.

[0029] Figure 2 Figure 2 Schematically shows a method for controlling Figure 1 the protection device according to an embodiment of the invention. Detailed Description of the Invention

[0030] In the specification, the term "pyrofuse" refers to a pyrotechnic electrical disconnection device.

[0031] Figure 1 Schematically and partially shows an electrical protection device 100 according to an embodiment of the invention.

[0032] Device 100 enables electrical protection of electrical equipment that can be located between the positive terminal 1011 and the negative terminal 1012 of the power supply 101 and the electrical load 102. The protected electrical equipment is formed by device 100 and the power harness connecting the electrical load 102 and the power supply 101 to device 100.

[0033] Device 100 includes a power contactor 120, a pyrotechnic electrical disconnection device 130 (commonly referred to as a pyrofuse), two Hall effect sensors 161 and 162, a pre-charge circuit 150, a relay 140, and a controller 110.

[0034] ​​​​The power contactor 120 includes a first contact 121 connected to the positive terminal 1011 of the power supply 101 and a second contact 122 connected to the negative terminal 1012 of the power supply 101. It enables the interruption of the current circulation between the power supply 101 and the electrical load 102.

[0035] The Hall effect sensors 161 and 162 are configured to measure the current flowing between the power supply 101 and the power contactor 120.

[0036] The pre - charge circuit 150 includes input terminals 151 and 152 located between the power supply 101 and the power contactor 120, and output terminals 153 and 154 connected to the electrical load 102. It enables the limitation of the current flowing towards the electrical load 102 before the power contactor 120 closes.

[0037] The relay 140 is connected to the input terminals 151 and 152 of the pre - charge circuit 150 so as to be able to connect it or disconnect it, i.e., send or not send current to it.

[0038] The thermal fuse 130 is connected to the negative terminal 1012 of the power supply 101 and the second contact 122 of the power contactor 120.

[0039] The controller 110 is configured to receive the current measurement values from the Hall effect sensors 161 and 162 and implement the reference Figure 2 described method, i.e., trigger the opening or closing of the power contactor 120 and the relay 140.

[0040] The device 100 may also include a fuse that is connected to the positive terminal 1011 of the power supply 101 and the first contact 121 of the power contactor 120. This fuse can protect the power supply 101 in the case of high currents (e.g., between 5 kA and 50 kA) and can also have an electrical protection different from that of the power supply 101.

[0041] The device 100 may also include a magnetic probe that is located between the thermal fuse 130 and the second contact 122 of the power contactor 120. This magnetic probe enables the detection of a short - circuit and triggers the opening of the thermal fuse 130, thereby protecting the electrical equipment. This enables fast and diverse current measurements using low - complexity electronics and improves the safety of the device 100.

[0042] Figure 2 Schematically and partially represents the method 200 for controlling Figure 1 the protection device 100 according to an embodiment of the present invention.

[0043] Method 200 includes closing relay 140 at 210 to connect the pre-charge circuit 150 to the electrical load 102; then closing power contactor 120 at 220 to transfer all electrical power (and thus all current) to the load 102; then opening relay 140 at 230. Finally, method 200 includes measuring the current flowing through protection device 100 at 240 using Hall effect sensors 161, 162, and comparing the measured current I mesure with two current thresholds I seuil1 and I seuil2 If the measured current I mesure is between the two current thresholds I seuil1 and I seuil2 then open power contactor 120; if the measured current I mesure is greater than the two current thresholds I seuil1 and I seuil2 then open thermal fuse 130.

[0044] The first current threshold I seuil1 is for example between the nominal current and 1 kA, and the second current threshold I seuil2 is for example between 1 kA and 5 kA. According to another example, the first current threshold I seuil1 is equal to the nominal current, and the second current threshold I seuil2 is equal to 1 kA.

[0045] The current measurement at 240 can also be performed by a magnetic current probe located between the thermal fuse 130 and the second contact 122 of the power contactor 120.

[0046] According to an embodiment of device 100, during step 240, the opening or closing of thermal fuse 130 can be commanded in different ways:

[0047] - by controller 110;

[0048] - by the magnetic current probe; or

[0049] - by a controller external to device 100, which makes it possible to control thermal fuse 130 independently of device 100.

[0050] Thus, if both the thermal fuse 130 and the contactor 120 are controlled by the controller 130 of the device, any opening of the thermal fuse 130 or the contactor 120 will be commanded by the controller 130, and the command depends on the current value measured during the measurement and comparison step 240.

[0051] If the thermal fuse 130 is controlled by a control system other than the controller 130, for example, a magnetic probe as described above, or by a control system external to the device 100, then during step 240 of measuring and comparing with the thresholds I seuil1 and I seuil2 any disconnection of the contactor 120 will always be controlled by the controller 130, but any disconnection of the thermal fuse will be controlled by that external device or by the magnetic probe.

[0052] Another subject of the present invention is a high-voltage DC distribution board, which includes the protection device of the present invention and an electrical circuit for powering an electrical load. The power-on electrical circuit is a pre-charge electronic system, which enables the capacitor of the electrical load to be charged with a constant current to avoid large current consumption (currents of several thousand amperes) during the communication of high-voltage DC (HVDC) power. This makes it possible to protect the load during switching, while being optimized in terms of quality and volume compared to traditional resistive systems.

[0053] In the case of an aircraft with electric propulsion, the board can be connected at its output terminals to different electrical loads of the aircraft and at its input terminals to the power supply of the aircraft. The power supply can be, for example, a high-voltage battery, and the electrical load can be an electric motor.

[0054] It can also be connected to the global control system of the aircraft and the emergency system of the aircraft. Thus, for example, the thermal fuse can be controlled by the global system and the emergency system of the aircraft.

[0055] Furthermore, the described distribution board makes it possible to optimize the distribution of the electrical components of the protection device and the power-on circuit, as well as the different electrical protections of the components present on the board.

Claims

1. An electrical device (100) for protecting an electrical equipment, the electrical equipment being intended to be located between a power supply (101) and an electrical load (102), the power supply (101) including a positive terminal (1011) and a negative terminal (1012), the device comprising: - A power contactor (120), the power contactor including a first contact (121) intended to be connected to the positive terminal (1011) of the power supply and a second contact (122) intended to be connected to the negative terminal of the power supply; - At least two Hall effect sensors (161, 162) configured to measure the current flowing between the power supply and the power contactor; - A pre-charge circuit (150), the pre-charge circuit including input terminals (151, 152) intended to be located between the power supply and the power contactor and output terminals (153, 154) intended to be connected to the electrical load; - A relay (140) configured to connect or disconnect the pre-charge circuit; - A pyrotechnic electrical disconnection device (130), the pyrotechnic electrical disconnection device being intended to be connected to the negative terminal of the power supply and the second contact of the power contactor; and - A controller (110) configured to receive the current measured by the Hall effect sensors and trigger the disconnection or closing of the power contactor and the relay.

2. The electrical protection device according to claim 1, further comprising a fuse intended to be connected to the positive terminal of the power supply and the first contact of the power contactor.

3. The electrical protection device according to any one of claims 1 or 2, further comprising a magnetic probe located between the pyrotechnic electrical disconnection device and the second contact of the power contactor, configured to detect a short circuit and trigger the disconnection of the pyrotechnic electrical disconnection device.

4. A high-voltage DC distribution board, comprising the protection device according to any one of claims 1 to 3 and an electrical circuit for powering an electrical load.

5. A method (200) for controlling an electrical protection device (100) according to any one of claims 1 to 3, comprising: - Closing (210) the relay (140) to connect the pre-charge circuit (150) to the electrical load (102); - Closing (220) the power contactor (120); - Disconnecting (230) the relay (140) to allow current to flow from the power supply (101) to the electrical load (102); and - The current flowing through the protection device is measured (240) by Hall effect sensors (161, 162), and the measured current (I mesure ) is compared with two predetermined thresholds (I seuil1 , I seuil2 ). If the measured current is between these two predetermined thresholds, the power contactor (120) is disconnected; or, if the measured current is greater than these two predetermined thresholds, the pyrotechnic electrical disconnection device (130) is disconnected.

6. The control method according to claim 5, wherein the measurement of the current flowing through the protection device is also performed by a magnetic probe.

7. An aircraft, comprising the electrical protection device according to one of claims 1 to 3 or the distribution board according to claim 4.

8. An aircraft, comprising the electrical protection device according to one of claims 1 to 3 and the distribution board according to claim 4.

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