Electrical device for protecting an electrical power supply installation

Abstract

The invention relates to an electrical device (100) for protecting an electrical installation intended to be placed between a power supply (101) and an electrical load (102), the device comprising: - a power contactor (120) comprising two contacts (121, 122) that are intended to be connected to the power supply; - at least two Hall sensors (161, 162) configured to measure the electric currents at the input of the power contactor; - an electrical precharging circuit (150) intended to be placed between the power supply and the power contactor and connected to the electrical load; - a relay (140) configured to connect or disconnect the electrical precharging circuit; - a pyrotechnic electrical cutoff device (130) intended to be connected to the power supply and to the power contactor, and - a controller (110) configured to receive the measurements from the Hall sensors and to open or close the power contactor and the relay.

Description

[0001] Description

[0002] Title of the invention: Electrical device for protecting an electrical power supply installation

[0003] Technical Field

[0004] The present invention relates to the general field of the protection of an electrical installation, and more particularly to the protection of a high voltage direct current power supply system.

[0005] Prior art

[0006] Electric vertical take-off and landing (eVTOL), electric conventional take-off and landing (eCTOL), and small short-haul aircraft (Air Taxi) platforms use new electric propulsion powered by high-voltage batteries. These high-voltage batteries, which contain significant amounts of energy, generally incorporate electrical protections based on fuses to interrupt the line in the event of a direct short circuit, i.e., when the two short-circuited points directly touch each other. These fuses thus protect the electrical source.

[0007] However, in the event of an overload or current flowing in an impedant short circuit, i.e. when the two short-circuited points are connected by an impedant medium, there is a first gray area between the protection provided by fuses and that provided by a power contactor, in which the aircraft wiring is not protected. There is also a second gray area during very high short-circuit currents which can cause the contactor to levitate and damage it, and also limit the current flowing in the fuse, which delays its tripping.

[0008] Thus, the fuses and contactors usually present in high voltage power supplies, for example based on high voltage batteries, do not always protect the electrical installation present between the electrical source and the load. It is therefore desirable to have a means of electrical protection to protect the electrical installation of power supply systems based on high voltage DC batteries.

[0009] Statement of the invention

[0010] The invention relates to an electrical device for protecting an electrical installation intended to be placed between an electrical power supply and an electrical load, the electrical power supply comprising positive and negative terminals, the device comprising:

[0011] - a power contactor comprising 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;

[0012] - at least two Hall effect sensors configured to measure the electrical currents flowing between the power supply and the power contactor;

[0013] - an electrical pre-charging circuit comprising input terminals intended to be placed between the electrical supply and the power contactor and output terminals intended to be connected to the electrical load;

[0014] - a relay configured to connect or disconnect the precharge electrical circuit;

[0015] - a pyrotechnic electrical cut-off device intended to be connected to the negative terminal of the power supply and to the second contact of the power contactor, and

[0016] - a controller configured to receive the electrical currents measured by the Hall effect sensors and to trigger an opening or closing of the power contactor and the relay.

[0017] The pyrotechnic electrical cut-off device, more commonly called a pyrofuse, is capable of opening the power circuit by a fuse effect when the currents are high (for example for currents up to 5 kA) or by a mechanical breaking effect thanks to the pyrotechnic actuator (present in the pyrofuse) for lower currents.

[0018] Thus, thanks to the device of the invention, the association of the pyrofuse and the power contactor makes it possible to open the power distribution line as soon as a short circuit or an overload appears.

[0019] Indeed, in the event of an overload, for example when the current measured by the Hall effect sensors is between the nominal current and 1 kA), the fault current is seen by the current measurements made by the Hall effect sensors and the controller can command the opening of the contactor. While in the event of a short circuit, for example when the current measured by the Hall effect sensors is between 1 kA and 5 kA, it is the pyrofuse which will be opened to protect the electrical installation.

[0020] According to a particular characteristic of the invention, the device also comprises a fuse intended to be connected to the positive terminal of the power supply and to the first contact of the power contactor.

[0021] This fuse provides additional protection for the electrical installation in the event of a major short circuit.

[0022] According to another particular characteristic of the invention, the device also comprises a magnetic probe, placed between the pyrotechnic electrical cut-off device and the second contact of the power contactor, configured to detect a short circuit and trigger the opening of the pyrotechnic electrical cut-off device.

[0023] Another object of the invention is a high voltage DC electrical power distribution board comprising the protection device according to the invention and an electrical circuit for energizing an electrical load.

[0024] Another object of the invention is a method for controlling the electrical protection device according to the invention comprising: closing the relay to connect the pre-charging circuit to the electrical load; - closing the power contactor;

[0025] - opening the relay to flow an electric current from the power supply to the electric load, and

[0026] - the measurement of an electric current flowing in the protection device by Hall effect sensors, the comparison of the measured electric current with two predetermined thresholds and the opening of the power contactor if the measured current is between these two predetermined thresholds or the opening of the electrical cut-off device by pyrotechnics if the measured current is greater than the two predetermined thresholds.

[0027] According to a particular characteristic of the invention, the measurement of the electric current flowing in the protection device is also carried out by a magnetic probe.

[0028] The invention also relates to an aircraft comprising an electrical protection device according to the invention and / or a distribution board according to the invention.

[0029] Brief description of the drawings

[0030] Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate exemplary embodiments thereof which are not limiting in nature.

[0031] [Fig. 1] Figure 1 represents, schematically and partially, the electrical protection device according to one embodiment of the invention.

[0032] [Fig. 2] Figure 2 schematically represents a method of controlling the protection device of Figure 1 according to one embodiment of the invention.

[0033] Description of the embodiments

[0034] In the description, the term "pyrofuse" designates the pyrotechnic electrical cut-off device. Figure 1 shows, schematically and partially, an electrical protection device 100 according to one embodiment of the invention.

[0035] The device 100 makes it possible to electrically protect an electrical installation which would be placed between the positive 1011 and negative 1012 terminals of an electrical power supply 101 and an electrical load 102. The electrical installation which is protected is formed of the device 100 and the power harnesses connecting the electrical load 102 and the electrical power supply 101 to the device 100.

[0036] The device 100 comprises a power contactor 120, a pyrotechnic electrical cut-off device 130, more commonly called a pyrofuse, two Hall effect sensors 161 and 162, a pre-charge circuit 150, a relay 140 and a controller 110.

[0037] The power contactor 120 comprises a first contact 121 which is connected to the positive terminal 1011 of the power supply 101 and a second contact 122 which is connected to the negative terminal 1012 of the power supply 101. It makes it possible to cut off the flow of current between the power supply 101 and the electrical load 102.

[0038] The Hall effect sensors 161 and 162 are configured to measure the electrical currents flowing between the power supply 101 and the power contactor 120.

[0039] The pre-charging electrical circuit 150 comprises input terminals 151 and 152 which are placed between the power supply 101 and the power contactor 120 and output terminals 153 and 154 which are connected to the electrical load 102. It makes it possible to limit the electrical current flowing to the electrical load 102 before the power contactor 120 closes.

[0040] The relay 140 is connected to the input terminals 151 and 152 of the pre-charging electrical circuit 150 in order to be able to connect or disconnect it, that is to say in order to send it or not electric current.

[0041] The pyrofuse 130 is connected to the negative terminal 1012 of the power supply 101 and to the second contact 122 of the power contactor 120. The controller 110 is configured to receive the current measurements from the Hall effect sensors 161 and 162 and to implement the method described with reference to FIG. 2, i.e. to trigger the opening or closing of the power contactor 120 and the relay 140.

[0042] The device 100 may also comprise a fuse connected to the positive terminal 1011 of the power supply 101 and to the first contact 121 of the power contactor 120. This fuse makes it possible to protect the power supply 101 in the event of a high current, for example between 5 kA and 50 kA, and also to have a dissimilarity of the electrical protection of the power supply 101.

[0043] The device 100 may also comprise a magnetic probe, placed between the pyrofuse 130 and the second contact 122 of the power contactor 120. This magnetic probe makes it possible to detect a short circuit and to trigger the opening of the pyrofuse 130 to protect the electrical installation. This makes it possible to have a rapid and dissimilar current measurement with less complex electronics and to improve the safety of the device 100.

[0044] Figure 2 represents, schematically and partially, a control method 200 of the protection device 100 of Figure 1 according to an embodiment of the invention.

[0045] The method 200 comprises the closing 210 of the relay 140 in order to connect the pre-charging circuit 150 to the electrical load 102, then the closing 220 of the power contactor 120 in order to transmit all the electrical power, therefore all the electrical current, to the load 102, and then the opening 230 of the relay 140. The method 200 finally comprises the measurement 240 of the electrical current flowing in the protection device 100 using the Hall effect sensors 161, 162 and the comparison of the measured current I meS two-threshold current I S euiii and I S euii2 in order to open the power contactor 120 if the measured current Imesure is between the two current thresholds I se uiii and I seuii2 or to open the pyrofuse 130 if the measured current Imesure is greater than the two current thresholds Iseuiii and Iseuiiz-

[0046] The first current threshold I seU iii is for example between the nominal current and 1 kA, and the second current threshold I seu ii2 is for example between 1 kA and 5 kA. According to another example, the first current threshold Iseuiii is equal to the nominal current and the second current threshold I seU ii2 is equal to 1 kA.

[0047] The measurement 240 of electric current can also be carried out by a magnetic current probe placed between the pyrofuse 130 and the second contact 122 of the power contactor 120.

[0048] Depending on the embodiment of the device 100, the opening or closing of the pyrofuse 130, during step 240, can be controlled in different ways:

[0049] - by controller 110;

[0050] - by the magnetic current probe; or

[0051] - by a controller external to the device 100, which allows for control of the pyrofuse 130 independent of the device 100.

[0052] Therefore, if the pyrofuse 130 and the contactor 120 are both controlled by the controller 130 of the device, the possible opening of the pyrofuse 130 or the contactor 120 will be controlled by the controller 130, according to the current values ​​measured during the measurement and comparison step 240.

[0053] If the pyrofuse 130 is controlled by a control system other than the controller 130, for example by the magnetic probe, as described previously or by a control system external to the device 100, then, during the measurement step 240 and comparison with the thresholds I seuiii and Iseuiiz, the possible opening of the contactor 120 will always be controlled by the controller 130 but the possible opening of the pyrofuse will be controlled by this external device or by the magnetic probe.

[0054] Another object of the invention is a high voltage DC electrical power distribution board comprising the protection device of the invention and an electrical circuit for energizing an electrical load. The electrical energizing circuit is an electronic pre-charging system which allows the capacitors of the electrical loads to be charged at a constant current, to avoid large current draws (current of a few kiloamperes) when communicating the high voltage DC power (HVDC). This allows the loads to be protected during switching by being optimized in mass and volume compared to a conventional resistance system. In the case of an electrically powered aircraft, the board can thus be connected at its output terminals to the various electrical loads of the aircraft and at its input terminals to the aircraft's electrical power sources.The power source can be, for example, a high-voltage battery and the electrical load an electric motor.

[0055] It can also be connected to the aircraft's overall control system and the aircraft's emergency system. The pyrofuse can thus, for example, be controlled by the aircraft's overall system and by the emergency system.

[0056] In addition, the distribution board as described makes it possible to optimize the distribution of the electrical components of the protection device and the power circuit as well as the various electrical protections of the components present on the board.

Claims

Claims

1. Electrical device (100) for protecting an electrical installation intended to be placed between an electrical power supply (101) and an electrical load (102), the electrical power supply (101) comprising positive (1011) and negative (1012) terminals, the device comprising: - a power contactor (120) comprising 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 (1012) of the power supply; - at least two Hall effect sensors (161, 162) configured to measure the electrical currents flowing between the power supply and the power contactor; - an electrical pre-charging circuit (150) comprising input terminals (151, 152) intended to be placed between the electrical 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-charging electrical circuit; - a pyrotechnic electrical cut-off device (130) intended to be connected to the negative terminal of the electrical supply and to the second contact of the power contactor, and - a controller (110) configured to receive the electrical currents measured by the Hall effect sensors and to trigger an opening or closing of the power contactor and the relay.

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

3. Electrical protection device according to any one of claims 1 or 2, also comprising a magnetic probe, placed between the pyrotechnic electrical cut-off device and the second contact. of the power contactor, configured to detect a short circuit and trigger the opening of the electrical cut-off device by pyrotechnics.

4. High voltage DC electrical power distribution board comprising the protection device according to any one of claims 1 to 3 and an electrical circuit for energizing an electrical load.

5. Method for controlling (200) the electrical protection device (100) according to any one of claims 1 to 3 comprising: - closing (210) the relay (140) to connect the pre-charging circuit (150) to the electrical load (102); - closing (220) of the power contactor (120); - opening (230) the relay (140) to flow an electric current from the power supply (101) to the electric load (102); and - the measurement (240) of an electric current flowing in the protection device by the Hall effect sensors (161, 162), the comparison of the measured electric current (I mesure) at two predetermined thresholds (Iseuiii, Iseuiiz) and the opening of the power contactor (120) if the measured current is between these two predetermined thresholds or the opening of the pyrotechnic electrical cut-off device (130) if the measured current is greater than the two predetermined thresholds.

6. Control method according to claim 5, in which the measurement of the electric current flowing in the protection device is also carried out by a magnetic probe.

7. Aircraft comprising an electrical protection device according to one of claims 1 to 3 or a distribution board according to claim 4.

8. Aircraft comprising an electrical protection device according to one of claims 1 to 3 and a distribution board according to claim 4.

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