Continuous electrical network and overcurrent protection system for a continuous electrical network.

Abstract

Continuous electrical network and overcurrent protection system for a continuous electrical network. The continuous electrical network (10) includes an electrical load (Z) supplied with electricity by a power source (S) to which the electrical load is connected by a first electrical line (12) and a second electrical line (14). An overcurrent protection system (16) having an input terminal (Pi) and an output terminal (Pe) is connected in series on the first electrical line. The overcurrent protection system (16) includes an electronic switch (20) connected in series between the input terminal (Pi) and the output terminal (Pe), an electrical current sensor (26), and a controller (22) configured to control the electronic switch. It also includes an electronic device (24) connected to the input terminal (Pi) and to the second electrical line (14).The controller (22) is configured to command a conductive state of the electronic device (24) when a current measurement from the electrical current sensor (26) is greater than a predetermined current threshold, and then to command an opening of the electronic switch (20). Figure for the abbreviation: Fig. 2.

Description

Description Title of the invention: Continuous electrical network and overcurrent protection system for a continuous electrical network.

[0001] — The invention relates to the field of continuous electrical networks, in particular High-voltage continuous electrical networks, installed on board aircraft. Aircraft are increasingly using onboard electrical systems, which This leads to increasingly high demands for onboard electrical power. This means there is a trend towards using increasingly higher levels of electrical voltage. high, especially in direct current. Thus, some modern aircraft have a high-voltage direct current electrical network, also called HVDC ("High Voltage Direct") Current (in English). Such an HVDC electrical network uses, for example, levels electrical voltage of +270V or -270V, or even +540V. The electrical network is used to power electrical loads, such as actuators, motors, pumps, etc. from at least one high-voltage electrical source continuous. Electrical charges are connected to the electrical source by lines. electrical. In order to protect the power lines and the power supply against an electrical fault (for example a short circuit) likely to occur at at or near electrical charges, at least one part of the power lines must be equipped with overvoltage protection systems current intensities. For example, electrical lines connected to a positive terminal of the power supply electrical equipment can be equipped with such overcurrent protection systems. In the case of an HVDC electrical network, given the voltage levels, a short-circuit current flowing in such a surge protection system Tensions can reach a very high intensity. This makes it all the more difficult the interruption of such a current by the overcurrent protection system. By Consequently, there is a need for an overcurrent protection system. allowing a very high intensity current to be stopped without risk of destruction of the overcurrent protection system. Description of the invention

[0002] — The present invention aims in particular to provide a solution to this problem. It concerns a continuous electrical network designed to supply electricity to electrical charge by an electrical power source, the electrical grid including:

[0003] — - said power supply, comprising a first pole and a second pole; and

[0004] — - said electric charge, comprising a first pole and a second pole; - a first electrical line connecting the first pole of the electrical load to the first pole of the electrical power supply; - a second electrical line connecting the second pole of the electrical load to the second pole of the electrical power source; - an overcurrent protection system mounted in series on the first power line, the overcurrent protection system comprising an input pole connected to the first pole of the power supply by an upstream part of the first power line and an output pole connected to the first pole of the electrical load by a downstream part of the first power line, in which the overcurrent protection system includes an electronic switch mounted in series between the input pole and the output pole, an electric current sensor intended to measure an electric current flowing between the input pole and the output pole, and a controller configured to control the electronic switch. The electrical network is remarkable in that the overcurrent protection system includes an electronic device comprising a first pole connected to the input pole of the overcurrent protection system and a second pole connected to the second electrical line, this electronic device being configured to exhibit a non-conductive state in normal operation and a conductive state when a command is applied to it. and in that the controller is configured to: - acquire an electric current measurement from the electric current sensor; - compare the current measurement to a predetermined current threshold; and - when the current measurement is above the predetermined current threshold, apply a command to the electronic device to control its conductive state, then command an opening of the electronic switch. Thus, when an overcurrent occurs in the first electrical line, the overcurrent protection system first activates its electronic device, resulting in a very high current flowing between the first electrical line, upstream of the electronic switch, and the second electrical line via the electronic device. This leads to a significant decrease in voltage on the first electrical line upstream of the electronic switch and consequently a significant decrease in the current flowing through the electronic switch, such that this current can be easily interrupted when the electronic switch is closed, without risk of damaging the electronic switch. In a particular embodiment, the electronic device includes a discharge tube. Specifically, the controller is configured to apply said The electronic device is controlled by applying a voltage higher than the discharge tube's trigger voltage between two poles of the discharge tube. Advantageously, one of the discharge tube poles is connected to the input pole of the protection system via a diode. In one alternative, the controller is configured to open the electronic switch after a predetermined time has elapsed since the command was applied to the electronic device. In another alternative, the controller is configured to open the electronic switch after the command was applied to the electronic device, when an electrical current measurement taken by the electrical current sensor falls below a second predetermined current threshold. In one embodiment, the controller is configured to stop applying the command to the electronic device after commanding the opening of the electronic switch. In an advantageous embodiment, the controller is configured to receive a reset command and to command a closure of the electronic switch in response to receiving a reset command. The invention also relates to an aircraft comprising such a continuous electrical network. The invention also relates to an overcurrent protection system for a direct current electrical network intended to supply electricity to an electrical load from an electrical power source, the electrical power source comprising a first pole and a second pole, and the electrical load comprising a first pole and a second pole. the continuous electrical network being configured in such a way that the first pole of the electrical load is connected to the first pole of the electrical power source by a first electrical line and the second pole of the electrical load is connected to the second pole of the electrical power source by a second electrical line, the overcurrent protection system being designed to be mounted in series on the first power line and comprising an input pole designed to be connected to the first pole of the power supply via an upstream portion of the first power line and an output pole designed to be connected to the first pole of the electrical load via a downstream portion of the first power line, and The overcurrent protection system includes an electronic switch mounted in series between the input and output poles, an electric current sensor designed to measure the electric current flowing between the input and output poles, and a controller configured to operate the switch. electronic. The overcurrent protection system is remarkable in that it comprises an electronic device including a first pole connected to the input pole of the overcurrent protection system and a second pole intended to be connected to the second electrical line, this electronic device being configured to be in a non-conductive state during normal operation and in a conductive state when a command is applied to it, and in that the controller is configured to: - acquire an electric current measurement from the electric current sensor; - compare the current measurement to a predetermined current threshold; and - When the current measurement exceeds the predetermined current threshold, apply a command to the electronic device to control its conductive state, then trigger the opening of the electronic switch. Description of embodiments The invention will be better understood upon reading the following description and examining the accompanying figures. Figure 1 illustrates an aircraft equipped with an electrical network conforming to one embodiment of the invention. Figure [Fig. 2] schematically illustrates an electrical network of an aircraft according to one embodiment of the invention. Figure [Fig.3] schematically illustrates a system for protecting against overvoltages in the electrical network of [Fig.2]. Figure 4 schematically illustrates a particular embodiment of the overcurrent protection system of Figure 3. Figure 5 schematically illustrates an aircraft electrical network according to another embodiment of the invention. Figure [Fig. 6] schematically illustrates a system for protecting against overvoltages in the electrical network of Figure [Fig. 5]. The electrical network 10 shown in [Fig. 2] corresponds to the electrical network of an aircraft such as aircraft 1 illustrated in [Fig. 1]. This electrical network comprises a power supply S having a first pole PSa and a second pole PSb, and an electrical load Z having a first pole PZa and a second pole PZb. The electrical network also includes a first electrical line 12 connecting the first pole PZa of the electrical load Z to the first pole PSa of the power supply S, and a second electrical line 14 connecting the second pole PZb of the electrical load Z to the second pole PSb of the power supply S, so as to allow the power supply to the charge Z by the power supply source S. The electrical network 10 further includes an overcurrent protection system 16 (labeled "PROT" in the figure) mounted in series on the first power line 12. This overcurrent protection system 16 has an input pole Pi connected to the first pole PSa of the power supply source S by an upstream part 12a of the first power line 12, and an output pole Pe connected to the first pole PZa of the electrical load Z by a downstream part 12b of the first power line 12. In operation, the power supply source S provides, at the output of its first pole PSa, a current il which flows on the connection 12a. As illustrated in [Fig. 3], the overcurrent protection system 16 includes an electronic switch 20 (labeled "SW" in the figure) connected in series across a link between the input terminal Pi and the output terminal Pe. The electronic switch 20 corresponds, for example, to an IGBT or MOSFET transistor. The overcurrent protection system 16 also includes an electric current sensor 26 for measuring the electric current flowing between the input terminal Pi and the output terminal Pe, and a controller 22 (labeled "CTRL" in the figure) configured to control the electronic switch 20 via a link 30.The overcurrent protection system 16 further includes an electronic device 24 comprising a first pole Pa connected to the input pole Pi of the overcurrent protection system 16 and a second pole Pb connected to a pole P3 of the overcurrent protection system 16, connected to the second electrical line 14 by an electrical link 13. The electronic device 24 is configured to exhibit a non-conductive state in normal operation and a conductive state when a command is applied to it by the controller 22 via a link 34. In the conductive state, the electronic device 24 behaves as a very low value impedance, for example an impedance less than 0.1 Ohm. Controller 22 is configured so that, during operation, it implements the following steps: - repeatedly acquire an electric current measurement from the electric current sensor 26; - compare the current measurement to a predetermined current threshold; and - when the current measurement is greater than the predetermined current threshold, apply a command to the electronic device 24 so as to control its conductive state, then command an opening of the electronic switch 20. Enabling the conductive state of the electronic device 24 results in a significant decrease in the voltage at the input terminal Pi of the overcurrent protection system 16, since the electronic device behaves then almost like a short circuit between the Pi pole and the P3 pole, except for the internal resistance of the electronic device 24, this decrease in voltage at the input Pi pole has the effect of reducing the voltage between the input Pi pole and the output Pe pole, and therefore of significantly reducing the electric current flowing on the connection between these two poles, and thus in the electronic switch 20. Consequently, when the controller 22 commands the opening of the electronic switch 20, the current intensity in the electronic switch 20 is sufficiently reduced to allow said opening to take place without risk of damaging the electronic switch 20. According to a first alternative, the controller 22 commands the opening of the electronic switch 20 after a predetermined time following the application of the command to the electronic device 24. According to a second alternative, after applying the command to the electronic device 24, the controller 22 repeatedly acquires a current measurement taken by the electric current sensor 26. When an electric current measurement is less than a second predetermined current threshold, the controller commands the opening of the electronic switch 20. Advantageously, the controller 22 stops the application of the conductive state command of the electronic device 24 after having commanded the opening of the electronic switch 20. In one embodiment, the controller 22 is powered by the power supply S to which it is connected. In another embodiment, the controller 22 is powered by a separate power supply, independent of the power supply S. This ensures the operation of the overcurrent protection system 16, even during the start-up of the electrical network 10. In particular, this separate power supply is a low-voltage supply, delivering, for example, a voltage of 28 volts DC. In a particular embodiment illustrated in [Fig. 4], the electronic device 24 includes a discharge tube 40. A discharge tube is a sealed tube containing a pair of electrodes and filled with a gas that is conductive only when a voltage greater than the discharge tube's trigger voltage is applied to the electrodes. When a voltage spike occurs in the circuit, the gas is ionized and becomes a conductive gas plasma, thus short-circuiting the energy spike corresponding to that voltage spike. Discharge tubes are often used to protect the inputs of sensitive circuits against disturbing transient voltages, particularly for lightning protection. Such a discharge tube is sometimes also called a gas discharge tube. The electronic device 24 also includes a power supply 42 (labeled "Sc" in the figure), controlled by the controller 22 via the link 34.The power supply. 42 is connected to two poles of the discharge tube 40 corresponding to its electrodes. This power supply is inactive when not controlled by the controller 22 and is configured to provide an output voltage higher than the trigger voltage of the discharge tube 40 when controlled by the controller 22. Thus, when the controller 22 sends a command to the power supply 42 via the connection 34, the power supply 42 applies a voltage across the discharge tube that is higher than the trigger voltage of the discharge tube. Consequently, this has the effect of controlling the conductive state of the discharge tube 40. Advantageously, the electronic device 24 further includes a diode 44 connected in series with the discharge tube, between one pole of the discharge tube and the input pole Pi of the overcurrent protection system 16.This prevents the propagation of voltage from the power supply source 42 into the electrical network. In one embodiment, the controller 22 includes an input for receiving a reset command. In one alternative, this input is for receiving a digital signal or an analog signal. In a second alternative, this input is a communication line for communicating with an aircraft computer. When it receives a reset command through this input, the controller 22 commands the electronic switch 20 to close.Thus, after the overcurrent protection system 16 is triggered (leading to the opening of the electronic switch 20) due to an overcurrent on the electrical connection 12 between the power source S and the electrical load Z, a command can be sent to the controller 22 to restore the power supply to the electrical load Z from the power source S (the controller 22 then commanding the electronic switch 20 to close). Advantageously, when said input corresponds to a communication line, this communication line also allows the controller 22 to inform the aircraft's computer of a triggering of the overcurrent protection system 16. This computer can then inform a crew member or maintenance personnel of the existence of a fault in the aircraft's electrical network 10. In a particular embodiment illustrated in [Fig. 5], the overcurrent protection system 16 is also connected in series on the second electrical connection 14. The overcurrent protection system 16 then comprises a pole Pib connected to the second pole PSb of the power supply S by a first section 14a of the second electrical connection 14, and a pole Peb connected to the second pole PZb of the electrical load Z by a second section 14b of the second electrical connection 14. The operation of the overcurrent protection system 16 The overcurrent protection for the second electrical connection 14 is similar to that already described for the first electrical connection 12. The overcurrent protection system 16 thus protects both the first electrical connection 12 and the second electrical connection 14 against overcurrents that may occur on these connections. As illustrated in [Fig. 6], when the overcurrent protection system 16 corresponds to the specific embodiment already described in relation to [Fig. 4], the overcurrent protection system 16 further comprises a second electronic switch 20b mounted in series on a connection between the poles Peb and Pib, and a second current sensor 26b connected to the controller 22 by a connection 36b. The controller 22 is further configured to control the electronic switch 20b via a connection 30b.Advantageously, although not necessarily, the overcurrent protection system 16 includes a second diode 44b mounted in series on a connection between a second pole of the discharge tube 40 and the Pib pole.

Claims

Demands

1. 1) Continuous electrical resistor (10) intended to supply electricity to electric charge (Z) by an electrical power source (S), the electrical network including: - said power supply source (S), comprising a first pole (PSa) and a second pole (PSb); and - said electric charge (Z), comprising a first pole (PZa) and a second pole (PZb); - a first power line (12) connecting the first pole (PZa) of the electric charge (Z) at the first pole (PSa) of the power supply electric; - a second power line (14) connecting the second pole (PZb) to the electric charge (Z) at the second pole (PSb) of the source power supply; - a series-connected overcurrent protection system (16) on the first power line, the over- protection system intensities comprising an input pole (Pi) connected to the first pole (PSa) of the power supply source by an upstream part (12a) of the first electrical line (12) and an output pole (Pe) connected to the first pole (PZa) of the electric charge (Z) by a downstream part (12b) of the first power line (12), in which the overcurrent protection system (16) includes an electronic switch (20) mounted in series between the input pole (Pi) and output pole (Pe), a current sensor electric (26) intended to measure an electric current flowing between the input pole (Pi) and the output pole (Pe), as well as a controller (22) configured to control the electronic switch, characterized in that the stab- protection system (16) voltages includes an electronic device (24) comprising a first pole (Pa) connected to the input pole (Pi) of the protection system (16) against overcurrents and a second pole (Pb) connected to the second line electrical (14), this electronic device being shaped to present a non-conductive state in normal operation and a conductive state when a command is applied to it, and in that the controller (22) is configured to: - acquire an electrical current measurement from the current sensor electric (26); - compare the current measurement to a predetermined current threshold; and - when the current measurement is higher than the pre- current threshold determined, apply a command to the electronic device (24) of way to control its conductive state, then control an opening of the electronic switch (20).

2. 2) Continuous electrical network according to claim 1, characterized in that that the electronic device comprises a discharge tube (40).

3. 3) Continuous electrical network according to claim 2, characterized in that that the controller is configured to apply said command to electronic device by controlling the application between two poles of the discharge tube, with a voltage greater than a dis- voltage triggering of the discharge tube.

4. 4) Continuous electrical network according to any one of the claims 2 or 3, characterized in that one of the poles of the discharge tube is connected to the input terminal of the protection system via a diode (44).

5. 5) Continuous electrical network according to any one of the claims 1 to 4, characterized in that the controller is configured to control the opening of the electronic switch (20) after a pre- determined after applying the command to the electronic device.

6. 6) Continuous electrical network according to any one of the claims 1 to 4, characterized in that the controller is contiguous to control the opening of the electronic switch after applying the command to the electronic device, when a current measurement The electrical current measured by the sensor is less than a second predetermined current threshold.

7. 7) Continuous electrical network according to any one of the claims previous ones, characterized in that the controller is configured for stop applying the command to the electronic device after having ordered the opening of the electronic switch.

8. 8) Continuous electrical network according to any one of the claims previous ones, characterized in that the controller is configured for to receive a reset order and to order a closing the electronic switch in response to a reception of a reset command.

9. 9) Aircraft (1), characterized in that it comprises an electrical network continuous (10) according to any one of the preceding claims.

10. 10) Overcurrent protection system (16) for a network continuous electric (10) intended to supply electricity to an electric load (Z) by means of an electric power supply (S), the electric power supply (S) comprising a first pole (PSa) and a second pole (PSb) and, the electric load (Z) comprising a first pole (PZa) and a second pole (PZb), the continuous electrical network being configured such that the first pole (PZa) of the electrical load (Z) is connected to the first pole (PSa) of the electrical power source by a first electrical line (12) and the second pole (PZb) of the electrical load (Z) is connected to the second pole (PSb) of the electrical power source by a second electrical line (14), the overcurrent protection system being intended to be mounted in series on the first power line and comprising an input pole (Pi) intended to be connected to the first pole (PSa) of the power supply by an upstream part of the first power line (12) and an output pole (Pe) intended to be connected to the first pole (PZa) of the electrical load (Z) by a downstream part of the first power line (12), the overcurrent protection system comprising an electronic switch (20) mounted in series between the input pole (Pi) and the output pole (Pe), an electric current sensor (26) intended to measure an electric current flowing between the input pole (Pi) and the output pole (Pe), and a controller (22) configured to control the electronic switch, the overcurrent protection system being characterized in that it comprises an electronic device (24) including a first pole (Pa) connected to the input pole (Pi) of the overcurrent protection system and a second pole (Pb) intended to be connected to the second electrical line (14), this electronic device being configured to exhibit a non-conductive state in normal operation and a conductive state when a command is applied to it, and in that the controller (22) is configured to: - acquire an electric current measurement from the electric current sensor; - compare the current measurement to a predetermined current threshold; and - when the current measurement exceeds the predetermined current threshold, apply a command to the electronic device (24) to control its conductive state, then control an opening electronic switch.