Device and method for protecting equipment powered by a high-voltage direct current bus

Abstract

The invention relates to a device (1) for protecting equipment (E) to be powered by a high-voltage DC bus (B), characterized by an inhibition circuit (15) for disconnecting the high-voltage DC supply source (S) and having a trigger (153) configured to assume, in response to an activation signal (S1), a position (P1) causing the transmission of a control signal (S2) to stop the source (S). The trigger (153) is connected to the first manual control (154), the actuation of which moves the trigger (153) from position (P1) to a second position that does not cause the transmission of signal (S2). The device also includes a circuit (13) for detecting abnormal voltage (VB), which is configured to send signal (S1) when a voltage (VB) exceeding a prescribed threshold (VMAX), greater than the nominal value (HVDCNOM) of the DC supply voltage, is detected. (See Figure for abbreviations.) 2

Description

Title of the invention: Device and method for protecting equipment powered by a high-voltage direct current bus

[0001] The invention relates to a device and a method for protecting equipment to be supplied by a high voltage direct current bus.

[0002] The field of the invention relates to any equipment which must be powered by a DC voltage source via the bus.

[0003] Due to the increasing voltages applied to equipment, particularly in the aeronautics industry where equipment electrification is increasingly common, the energies involved quickly become very significant (the stored energy being proportional to the square of the voltage). In the event of an unexpected overvoltage during testing, for example resulting from a malfunction of the equipment or the assembly in which the equipment is integrated, it is imperative to shut down the power source.

[0004] During testing campaigns on the equipment, it is possible in the event of a problem (for example, a hardware failure) or in the event of incorrect handling of the source or the load connected to the equipment, that the high DC voltage of the bus supplying the equipment may increase rapidly and uncontrollably due to the flow of significant energy.

[0005] The prior art includes sources supplying the high voltage direct current on the bus, these sources having a disconnecting device from the bus in case of overvoltage of the latter.

[0006] But this disconnection is generally slow, on the order of a few hundred milliseconds, which does not allow for effective protection of the equipment which has internal components very sensitive to overvoltages, components which can be damaged in a few milliseconds if no protection is triggered due to the energy levels involved.

[0007] Excess energy is dangerous for the equipment, because it is not designed to withstand it in situations resulting from a failure or malfunction of its environment, even less so during tests taking place at the beginning of its development cycle, i.e. at a time when the equipment may still have design weaknesses that will subsequently be resolved.

[0008] An objective of the invention is to obtain a device and a method for protecting equipment which is to be powered by a high voltage DC bus during its operation, which overcomes the disadvantages mentioned above and which makes it possible to effectively protect the equipment.

[0009] To this end, a first object of the invention is a protection device for equipment to be powered by a high-voltage DC bus, the protection device comprising a first connection terminal to a first conductor of the bus and a second connection terminal to a second conductor of the bus, the first conductor and the second conductor being intended to connect the equipment to a high-voltage DC power supply intended to apply between them a high-voltage DC supply to the equipment having a nominal value of DC supply voltage, characterized in that the protection device further comprises: an inhibition circuit, intended to cut off the high-voltage DC power supply, the inhibition circuit comprising an activation input, at least one control output of the high-voltage DC power supply, a trip unit and a first manual control disposed on an external surface of the protective device, the trigger being configured to take and hold, in response to a prescribed activation signal on the activation input, a first position, which causes a stop control signal to be sent from the high DC voltage power supply to at least one control output, the trigger being connected to the first manual control, which is configured such that actuation of the first manual control moves the trigger from the first position to a second position without causing the shutdown control signal to be sent from the high-voltage DC power supply to at least one control output, an abnormal voltage detection circuit, which is connected between the first terminal and the second terminal, which has an activation output connected to the activation input and which is configured to send the prescribed activation signal on the activation output, when a voltage greater than a first prescribed threshold of DC voltage, greater than the nominal value of the high DC supply voltage, is detected between the first terminal and the second terminal.

[0010] Thanks to the invention, the occurrence of an overvoltage on the bus relative to the nominal DC supply voltage is quickly detected by the circuit to trigger the inhibition of the source and thus stop the external power supply to the equipment as quickly as possible. The trigger according to the invention locks the device in the first position for sending the control signal to stop the high DC supply voltage, which eliminates the overvoltage on the bus and therefore on the equipment. The device according to the invention ensures that the trigger can only be reset to the second position manually by the first command, which prevents the device from returning to the second position on its own. and this ensures that the device remains in the first position after the source is switched off to prevent the source from being switched back on and causing further damage to the equipment.

[0011] According to one embodiment of the invention, the protection device includes a power bypass circuit connected between the first terminal and the second terminal. This power bypass circuit diverts the temporary increase in energy, due to an overvoltage present on the bus, away from the equipment, thus providing greater protection for the equipment.

[0012] According to one embodiment of the invention, the power bypass circuit comprises at least one first resistor and at least one power switch, which are in series between the first terminal and the second terminal, the power switch having a control input connected to the activation output and being configured to take a connection state of the first resistor between the first terminal and the second terminal in the case where the prescribed activation signal is present on the control input and to take a disconnection state of the first resistor between the first terminal and the second terminal in the case where the prescribed activation signal is absent on the control input.

[0013] According to one embodiment of the invention, the power switch comprises at least one transistor.

[0014] According to one embodiment of the invention, the abnormal voltage detection circuit comprises a resistive voltage divider bridge having at least a second resistor and at least a third resistor, which are connected in series between the first terminal and the second terminal, and a voltage comparator, which is connected in parallel with the at least a third resistor and which is configured to compare the voltage in parallel with the at least a third resistor to a prescribed reference voltage, equal to a prescribed divisor factor multiplied by the first prescribed DC voltage threshold, the prescribed divisor factor being equal to the resistive value of the at least a third resistor, divided by the sum of the resistive value of the at least a second resistor and the resistive value of the at least a third resistor, the voltage comparator being configured to send the prescribed activation signal on the activation output,in the event that the voltage in parallel with at least a third resistor is greater than the prescribed reference voltage.

[0015] According to one embodiment of the invention, the trigger comprises a bistable relay having as stable states only the first position and the second position.

[0016] According to one embodiment of the invention, the protection device comprises a power supply circuit, configured to supply power from the first terminal and second terminal the abnormal voltage detection circuit and / or the inhibition circuit.

[0017] According to one embodiment of the invention, the protection device includes a test circuit for sending the activation signal prescribed by the abnormal voltage detection circuit, the test circuit comprising a second manual control disposed on the outer surface of the protection device and at least one external indicator disposed on the outer surface of the protection device, the external indicator being configured to send a first voltage presence signal to the outside when a voltage less than or equal to the first prescribed DC voltage threshold is present between the first terminal and the second terminal, the second manual control being configured such that actuation of the second manual control causes a test of sending the activation signal prescribed by the abnormal voltage detection circuit,The transmission by the external indicator of the first voltage presence signal to the outside in the event that the prescribed activation signal has not been sent by the abnormal voltage detection circuit, and the absence of transmission by the external indicator of the first voltage presence signal to the outside in the event that the prescribed activation signal has been sent by the abnormal voltage detection circuit.

[0018] According to one embodiment of the invention, the inhibition circuit includes at least one other control output of a load intended to be connected to the equipment, the first position of the trigger causing the sending of a control signal to stop the load on the other control output.

[0019] A second object of the invention is a method for protecting equipment to be powered by a high-voltage DC bus using the protection device as described above, the first terminal of which is connected to the first conductor of the bus and the second terminal of which is connected to the second conductor of the bus, the first conductor and the second conductor connecting the equipment to a high-voltage DC power supply intended to apply between them a high-voltage DC supply to the equipment having a nominal value of DC supply voltage, characterized in that the method further comprises the following steps: actuation of the first manual control to move the trigger from the first position to the second position without causing the sending of the stop control signal of the high-voltage DC power supply to at least one control output,The voltage between the first terminal and the second terminal is measured by the abnormal voltage detection circuit, which then sends the prescribed activation signal to the output. activation connected to the activation input, in the case where the voltage between the first terminal and the second terminal is greater than the first prescribed threshold of DC voltage, greater than the nominal value of the DC supply voltage of the high DC supply voltage, in response to the fact that the prescribed activation signal is present on the activation input, switching of the trigger from the second position to the first position, which causes the stop control signal of the high DC supply voltage source to be sent to at least one control output connected to the high DC supply voltage source.

[0020] The invention will be better understood upon reading the following description, given solely by way of non-limiting example with reference to the figures below of the attached drawings.

[0021] [Fig. 1] represents an electrical diagram of equipment on which the protection device and the protection method according to the invention can be used.

[0022] [Fig.2] represents an electrical diagram of the protection device according to the invention in a first triggered position of stopping the continuous high voltage power supply source.

[0023] [Fig.3] represents an electrical diagram of the protection device according to the invention in a second position triggered manually so as not to cause the shutdown of the high voltage DC power supply source.

[0024] [Fig.4] represents an electrical diagram of a voltage detection circuit of the protective device according to an embodiment of the invention.

[0025] [Fig. 5] represents a flowchart of a protection process according to a mode of realization of the invention.

[0026] An example of a protection device 1 according to embodiments of the invention is described in more detail below with reference to Figures 1 to 4, and an example of a protection method having the steps mentioned below according to embodiments of the invention is described with reference to Figure 5. In Figures 1 to 4, electrical nodes are symbolically represented by circular dots, while the intersections between lines, which are not circular dots, are not nodes.

[0027] In [Fig. 1], a piece of equipment E is powered by a high-voltage DC bus B. The high-voltage DC bus B comprises a first conductor B1 and a second conductor B2, which connect a high-voltage DC power supply S to the equipment E and carry the high-voltage DC supply, provided by the source S, to the equipment E, in the event that the source S is not switched off. The high-voltage DC power supply S applies the high voltage between the first conductor B1 and the second conductor B2. The equipment E has a prescribed HVDC supply voltage rating, HVDCNom, when the source S is not switched off. The source S is externally switchable and therefore includes one (or more) 1520 inputs for receiving a switch command, suitable for connection to the outside of the source S. The prescribed HVDCNom value is the value of the high-voltage HVDC supply provided by the source S on the bus B in the absence of abnormal voltage and overvoltage on the bus B. The equipment E can be connected to a load Z.

[0028] The equipment E may be, for example, electrical power equipment, an actuator, an inverter, a motor, an electric motor intended for use in an aircraft, or other such equipment. The equipment E and / or the load Z may, for example, be part of a test bench for one of these elements, this test bench being used for the development of that element.

[0029] The protection device 1 is intended to be connected in parallel with the equipment E on the bus B. The protection device 1 has a first terminal 11 intended to be connected to the first conductor B1 of the bus B and a second terminal 12 intended to be connected to the second conductor B2 of the bus B. The voltage present between the second terminal 12 and the first terminal 11 is called the voltage VB.

[0030] In [Fig. 2], the protection device 1 includes an abnormal voltage VB detection circuit 13 on the bus B, this circuit 13 being connected between the first terminal 11 and the second terminal 12. The abnormal voltage VB detection circuit 13 is configured to send, during the first step El, the prescribed activation signal SI on the activation output 131 of the circuit 13, when a voltage VB exceeding a first prescribed threshold VMax of DC voltage, greater than the nominal value HVDCNOm of the high DC supply voltage HVDC (in the case of overvoltage VB), is detected by the circuit 13 between the first terminal 11 and the second terminal 12. The abnormal voltage VB detection circuit 13 makes it possible to measure the voltage VB between the first terminal 11 and the second terminal 12.The abnormal voltage VB detection circuit 13 includes a circuit 130 for comparing the voltage VB present between the first terminal 11 and the second terminal 12 to the first prescribed threshold VMAx of DC voltage, to send during the first step El the prescribed activation signal SI on the activation output 131 in the case where the voltage VB present between the first terminal 11 and the second terminal 12 is greater than the first prescribed threshold VMAx of DC voltage, and not to send the prescribed activation signal SI on the activation output 131 in the case where the voltage VB present between the first terminal 11 and the second terminal 12 is less than or equal to the first prescribed threshold VMax of DC voltage.

[0031] The abnormal VB voltage detection circuit 13 can be made up of analog components, which allows for a very short response time.

[0032] According to an embodiment of the invention, the comparison circuit 130 of the abnormal voltage detection circuit 13 VB is configured to send, during the first step El, the prescribed activation signal SI on the activation output 131, in the case where the voltage VB present between the first terminal 11 and the second terminal 12 is greater than the first prescribed threshold VMax of DC voltage, and not to send the prescribed activation signal SI on the activation output 131 when both the voltage VB present between the first terminal 11 and the second terminal 12 is less than or equal to the first prescribed threshold VMAx of DC voltage.

[0033] The comparison circuit 130 can be formed from one or more analog components, which allows for a very short response time.

[0034] The protection device 1 includes an inhibition circuit 15, designed to disconnect the high-voltage DC power supply S when certain conditions verified by the inhibition circuit 15 are met. The inhibition circuit 15 comprises an activation input 151, one (or more) control outputs 152 for the high-voltage DC power supply S, a trigger 153, and a first manual control 154 located on an external surface 18 of the protection device 1. The activation output 131 of the abnormal voltage detection circuit 13 is connected to the activation input 151 of the inhibition circuit 15. The control output 152 may consist of two conductors. The inhibition circuit 15 may consist of one or more analog components.

[0035] During the first step El, the presence of the prescribed activation signal SI on the activation input 151 causes the trigger 153 to switch to and then hold in a first position PI ([Fig. 2]), which triggers the sending of a stop command signal S2 from the high-voltage DC power supply S to the control output 152. The control output 152 is connected to the stop command input(s) 1520. The stop command signal S2 from the high-voltage DC power supply S on the control output 152 causes the high-voltage DC power supply S to stop during the first step El, which then no longer supplies the high-voltage DC power supply on the bus B between the first conductor B1 and the second conductor B2.The shutdown of the high-voltage DC power supply source S can be achieved by disconnecting the source S from the first conductor B1 and the second conductor B2 of bus B, using internal switches (e.g., contactors or others) within the source, which are activated by the presence of the stop command signal S2 on the stop command input(s) 1520. This provides protection. Equipment E is protected against overvoltages. The control signal S2 on the control output 152 allows the high-voltage DC power supply S to be cut off to stop the energy supply to equipment E.

[0036] In the case where the abnormal voltage detection circuit 13 and the inhibition circuit 15 are made up of analog components, the control signal S2 on the control output 152 can thus be triggered 20 milliseconds after the appearance of the overvoltage between the first terminal 11 and the second terminal 12. This gain in reactivity is due to the fact that each analog component has a very short response time, which can be on the order of a hundred nanoseconds.

[0037] According to one embodiment of the invention, the stop control signal S2 can be an open circuit or high impedance signal on the control output 152.

[0038] According to another embodiment of the invention, the stop control signal S2 can be a closed circuit or short circuit or low impedance signal on the control output 152.

[0039] In Figures 2 and 3, the trigger 153 is connected to the first manual control 154. The actuation of the first manual control 154 by a user during the second step E2 following the first step El causes the trigger 153 to move from the first position PI to the second position P2, known as the reset position, ([Fig.3]), not causing the sending of the stop command signal S2 of the high voltage DC supply source S on the control output 152 (or causing the sending of the start command signal S3 of the high voltage DC supply source S on the control output 152).The absence of the S2 control signal to stop the high voltage DC supply source S on the control output 152 or the presence of the S3 control signal to start the high voltage DC supply source S on the control output 152 causes the high voltage DC supply source S to start during the second stage E2, which then supplies the high voltage DC HVDC supply on the bus B between the first conductor B1 and the second conductor B2.

[0040] The high-voltage DC power supply S can only be restarted manually by manually actuating the first manual control 154 to move the trigger 153 from the first position P1 to the second position P2. This prevents the protection device 1 from returning to the second position P2 on its own following the reappearance of high voltage HVDC on bus B, which could be unintentional and undesired. This prevents damage to the equipment E if a residual voltage is still present on bus B.

[0041] Between the first step E1 and the second step E2, the possible absence of the prescribed activation signal SI on the activation input 151 keeps the trigger 153 in the first position PI ([Fig. 2]), which causes the shutdown control signal S2 of the high-voltage DC power supply S to be sent to the control output 152. The trigger 153 therefore retains a memory of the last activation signal SI present on the activation input 151 to keep the trigger 153 in the first position PI ([Fig. 2]), which causes the shutdown control signal S2 of the high-voltage DC power supply S to be sent to the control output 152, until the actuation of the first manual control 154 by a user during the second step E2 causes the trigger 153 to move from the first position PI to the second position P2 of reset ([Fig. 3]).This memory can be mechanical or electromechanical, as for example in the case of a relay described below.

[0042] Indeed, once the S2 control signal for stopping the high-voltage DC power supply source S is present on the control output 152 during the first step El, the high-voltage DC power supply source S is stopped and no longer supplies the high-voltage DC power supply on the bus B between the first conductor B1 and the second conductor B2. The voltage VB between the first terminal 11 and the second terminal 12 can then fall below the first threshold Vmax, which means that in this case the abnormal voltage VB detection circuit 13 will only detect that the voltage VB between the first terminal 11 and the second terminal 12 is above the first threshold VMax, and will no longer supply the prescribed activation signal SI on the activation input 151.In this case, the trigger 153 is held in the first position PI until the actuation of the first manual control 154 by a user during the second step E2 causes the trigger 153 to move from the first position PI to the second reset position P2 ([Fig.3]). This allows the stop command signal S2 of the high-voltage DC power supply S to be stored, even after all power has been lost on bus B.

[0043] The first step El is preceded by an initial step E0 during the installation of the protection device 1 on bus B and on the source S. During the initial step E0, a user activates the first manual control 154 to move the trigger 153 to the second position P2 ([Fig. 3]), without sending the stop command signal S2 of the high-voltage DC supply source S to the control output 152 (or causing the start command signal S3 of the high-voltage DC supply source S to be sent to the control output 152). The absence of the stop command signal S2 of the high-voltage DC supply source S The presence of a DC supply voltage on the control output 152, or the presence of the S3 control signal for switching on the high DC supply source S, on the control output 152, causes the high DC supply source S to switch on during the initial step E0. This source then supplies the high DC supply voltage (HVDC) on the bus B between the first conductor B1 and the second conductor B2. The initial step E0 is therefore analogous to the second step E2.

[0044] According to one embodiment of the invention, the first manual control 154 only allows the trigger 153 to be moved from the first position PI to the second position P2 of resetting, and not from the second position P2 of resetting to the first position PL

[0045] The first manual control 154 may be in the form of a push button or a lever or a handle or other, and is accessible on the outer surface 18 of the protective device 1 by a user.

[0046] According to one embodiment of the invention, the first manual control 154 is in a first arrangement DI with respect to the outer surface 18 in the first position PI of the trigger 153, and is in a second arrangement D2 with respect to the outer surface 18 in the second position P2 of the trigger 153, this second arrangement D2 being different from the first arrangement DI.

[0047] According to one embodiment of the invention, the trigger 153 is bistable, that is, it has as stable states only the first position PI and the second position P2 of reset. The trigger 153 may be or include a bistable (electromechanical) relay 1530 or a bistable (electromechanical) contactor 1530. The fact that the trigger 153 or relay 1530 is bistable allows, once the prescribed activation signal SI is present on the activation input 151 and has triggered the stop control signal S2 of the high-voltage DC supply source S on the control output 152, for this activation signal SI present on the activation input 151 to maintain the trigger 153 or relay 1530 in the first position PI ([Fig. 2]), as indicated above.

[0048] The bistable relay 1530 has its input circuit connected to the activation input 151, for example via an isolator. Thus, the bistable relay 1530 can be controlled by the isolator in the inhibit circuit 15. This isolator isolates the abnormal voltage detection circuit 13, which is referenced to the high-voltage DC bus B, from the source S to be controlled, thereby protecting both the source and the users.

[0049] The bistable relay 1530 has its input circuit connected to the activation output 131. The moving part of the bistable relay 1530 is connected to the first manual control 154. so that the moving part can be operated from the first position PI to the second position P2 by the first manual control 154.

[0050] According to one embodiment of the invention, the protection device 1 comprises a power bypass circuit 14 connected between the first terminal 11 and the second terminal 12. This power bypass circuit 14 allows the excess energy stored on the bus B to be discharged and dissipated once the bus B experiences an overvoltage VB exceeding the first threshold VMax. The power bypass circuit 14 allows the excess energy stored on the bus B to be discharged and dissipated once the presence of the control signal S2, which shuts down the high-voltage DC power supply S, on the control output 152, during the first step E1. Indeed, this excess energy can prove dangerous and destructive to the equipment E or to a user who might attempt to intervene in the operation.This allows the residual energy to be diverted to a circuit other than the equipment itself, as the equipment is not designed to withstand such a temporary overload. This protects equipment E from unwanted overvoltages on bus B, which could damage the equipment, and dissipates the excess energy in the dedicated power bypass circuit 14, preventing this excess energy from reaching and damaging the equipment.

[0051] According to one embodiment of the invention, the power bypass circuit 14 comprises one (or more) first power electrical resistor 141 and one (or more) power switch 142, which are connected in series between the first terminal 11 and the second terminal 12. The control input 143 of the power switch 142 is connected to the activation output 131.

[0052] The power switch 142 enters a connection state of the first resistor 141 between the first terminal 11 and the second terminal 12 when the prescribed activation signal SI is present at the control input 143. In this connection state, the energy present between the first terminal 11 and the second terminal 12 is dissipated in the first resistor(s) 141.

[0053] The power switch 142 takes a disconnect state of the first resistor 141 between the first terminal 11 and the second terminal 12, in the case where the prescribed activation signal SI is absent on the control input 143.

[0054] The power switch 142 can be made of one (or more) analog components, which allows for a very short response time. The power switch 142 can be semiconductor. According to one embodiment of the invention, the power switch 142 comprises one (or more) transistors 144, such as, for example, one (or more) IGBT (insulated-gate bipolar transistor) type transistor(s), or one (or more) thyristor(s) or other. The resistor(s) 141 is (or are) consisting of one or more analog components. The power bypass circuit 14 can thus be triggered (transition to the conductive state of the power switch 142) a time on the order of one millisecond after the sending of the prescribed activation signal SI on the control input 143.

[0055] According to one embodiment of the invention, the bypass circuit 14 is activated at the same time as the stop control signal S2 is sent to the control output 152 of the source S. As this circuit 14 can be faster to trigger (on the order of 1ms as indicated above) than the source S, there can be a short period of time during which the source S is still delivering power and the bypass circuit 14 is active.

[0056] According to one embodiment of the invention, in [Fig. 4], the abnormal voltage VB detection circuit 13 comprises, as a voltage VB comparison circuit 130, a resistive voltage divider 132 and a voltage comparator 135. The resistive voltage divider 132 comprises one (or more) second electrical resistor(s) 133 and one (or more) third electrical resistor(s) 134, which are connected in series between the first terminal 11 and the second terminal 12. The abnormal voltage VB detection circuit 13 comprises a voltage comparator 135, which is connected in parallel with the third resistor(s) 134. The voltage comparator 135 comprises a comparison input 137 connected to the node 139 linking the second electrical resistor 133 to the third electrical resistor 134.The third electrical resistor(s) 134 is connected between node 139 and a reference input 138 of the voltage comparator 135, this reference input 138 being connected to the second terminal 12. The second electrical resistor(s) 133 is connected between node 139 and the first terminal 11. During the first step E1, the voltage comparator 135 compares the voltage V3, which is located between the comparator input 137 and the reference input 138, to a prescribed reference voltage VREF, which is present between an input 136 of the comparator 135 and the reference input 138. The prescribed reference voltage Vref is equal to a prescribed divisor multiplied by the first prescribed threshold VMax of the DC voltage. This prescribed divisor coefficient is equal to R3 / (R2+R3), where R3 is the resistive value of the third resistance (or resistances) 134 and R2 is the resistive value of the second resistance (or resistances) 133.The voltage comparator 135 generates the prescribed activation signal SI on the activation output 131, in the event that the voltage V3 in parallel with the third resistor(s) 134 is greater than the prescribed reference voltage VREF. The resistor(s) 133 is (or are) formed of one or more analog components. The resistor(s) 134 is (or are) formed of one or more analog components.

[0057] According to one embodiment of the invention, 0 < R3 / (R2+R3) <0.1. In particular, 0 < R3 / (R2+R3) <0.01.

[0058] According to one embodiment of the invention, the nominal value HVDCN0M of the DC supply voltage is greater than or equal to 500 V and less than or equal to 1000 V. Of course, the nominal value HVDCNOm of the DC supply voltage could be outside this range.

[0059] According to one embodiment of the invention, the nominal value HVDCN0M of the DC supply voltage can be greater than or equal to 700 V and less than or equal to 800 V. Of course, the nominal value HVDCN0M of the DC supply voltage could be outside this range.

[0060] According to one embodiment of the invention, the first prescribed threshold VMax of DC voltage is greater than or equal to 500 V and less than or equal to 1200 V, while being greater than the nominal value HVDCNOm of DC supply voltage as indicated above. Of course, the first prescribed threshold VMax of DC voltage could be outside this range, while still being greater than the nominal value HVDCNom of DC supply voltage as indicated above.

[0061] According to one embodiment of the invention, the protection device 1 comprises a power supply circuit 17, configured to supply power from the first terminal 11 and the second terminal 12 to the abnormal voltage detection circuit 13 and / or the inhibition circuit 15. The power supply circuit 17 thus supplies power to the abnormal voltage detection circuit 13 and / or the inhibition circuit 15 from the high DC supply voltage (HVDC) (or the nominal value of the HVDCN0M DC supply voltage) present between the first terminal 11 and the second terminal 12. The power supply circuit 17 comprises an input portion 171 connected to the first terminal 11 and the second terminal 12, and an output portion 172 connected to the abnormal voltage detection circuit 13 and / or the inhibition circuit 15.The input section 171 includes a step-down circuit configured to reduce the high DC supply voltage (HVDC) (or the nominal value of the HVDCN0M DC supply voltage) present between the first terminal 11 and the second terminal 12 to a DC supply voltage Val, which is lower than the high DC supply voltage (HVDC) (or the nominal value of the HVDCNOm DC supply voltage) and is present at the output section 172 for supply to the abnormal voltage detection circuit 13 (VB) and / or the inhibiting circuit 15. The power supply circuit 17 allows the protection device 1 to be self-powered for ease of use. Such a power supply circuit can be particularly advantageous when... of relatively long test campaigns. The power supply circuit 17 allows the protection device 1 to be powered directly by the bus B and thus remain functional as long as the voltage on bus B has not completely disappeared. The power supply circuit 17 can be made up of one or more analog components.

[0062] According to one embodiment of the invention, 0 < Val / HVDC <0.1. In particular, 0 < Val / HVDC < 0.01.

[0063] According to one embodiment of the invention, 0 < Val / HVDCN0M <0.1. In particular, 0 < Val / HVDCN0M < 0.01.

[0064] For example, Val < 20 V. For example, Val = 15 V. Of course, Val can have other values ​​than this example.

[0065] According to one embodiment of the invention, the protection device 1 includes a circuit 16 for testing the operation of the abnormal voltage VB detection circuit 13, i.e., for testing the transmission of the activation signal SI prescribed by the abnormal voltage VB detection circuit 13. The test circuit 16 includes a second manual control 161 located on the outer surface 18 of the protection device 1 and one (or more) external indicator 162 for the presence of high DC voltage (HVDC) supply between the first terminal 11 and the second terminal 12, this (or these) indicator 162 being located on the outer surface 18 of the protection device 1. The external indicator 162 is (or is) visual and / or audible.The external indicator 162 is configured to send a first voltage presence signal to the outside (which may be sending a first light signal to the outside and / or sending a first audible signal to the outside), when a voltage VB less than or equal to the first prescribed threshold VMax of DC voltage (and greater than another threshold less than the nominal value HVDCN0M of DC supply voltage) is present between the first terminal 11 and the second terminal 12.The external indicator 162 is configured not to send the first voltage presence signal to the outside (or to send another voltage absence signal, which may be sending a second light signal different from the first light signal to the outside and / or sending a second audible signal different from the first audible signal to the outside), when a voltage VB less than or equal to the first prescribed threshold VMAx of DC voltage (and greater than another threshold less than the nominal HVDC supply voltage) is present between the first terminal 11 and the second terminal 12.

[0066] The actuation of the second manual control 161 by a user during the third step E3, which is subsequent to the initial step E0 or subsequent to the first step E1 or subsequent to the second step E2, causes the circuit 16 to perform test a test of the sending of the activation signal SI prescribed by the abnormal voltage detection circuit 13 VB.

[0067] In the event of correct operation of the abnormal voltage detection circuit 13 VB, this functional test causes the prescribed activation signal SI to be sent to the activation output 131, which causes the trigger 153 to send the stop command signal S2 of the high voltage DC supply source S to the control output 152, the connection state of the power bypass circuit 14, the cutting off of the high voltage DC supply source S, as well as the absence of sending by the external indicator 162 of the first signal of presence of voltage to the outside, due to the fact that there is no longer any voltage applied by the source S having been cut off.

[0068] In the event of incorrect operation of the abnormal voltage detection circuit 13, this functional test does not cause the prescribed activation signal SI to be sent to the activation output 131. Consequently, the trigger 153 does not send the shutdown control signal S2 from the high-voltage DC power supply source S to the control output 152, nor does it activate the power bypass circuit 14, nor does it disconnect the high-voltage DC power supply source S. In this case, because the voltage applied by the source S has not been disconnected, the external indicator 162 continues to send the initial voltage presence signal externally.

[0069] Therefore, during this functional test, the second manual control 161 is configured such that actuation of the second manual control 161 causes the external indicator 162 to send the first voltage presence signal to the outside if the prescribed activation signal SI has not been sent by the abnormal voltage detection circuit 13 VB. This case corresponds to the incorrect operation of the abnormal voltage detection circuit 13 VB during the test. The user thus realizes, by the fact that the external indicator 162 still sends the first voltage presence signal to the outside, that the abnormal voltage detection circuit 13 VB is not functioning correctly following the test.

[0070] During this functional test, the second manual control 161 is configured such that actuation of the second manual control 161 causes the external indicator 162 to not send the first voltage presence signal to the outside in the event that the prescribed activation signal SI has been sent by the abnormal voltage detection circuit 13 VB. This case corresponds to the correct operation of the abnormal voltage detection circuit 13 VB during the test. The user thus realizes, by the fact that the external indicator 162 of the first If the voltage presence signal no longer sends the initial voltage presence signal externally, then the abnormal voltage detection circuit 13 (VB) is functioning correctly following the test. The test circuit 16 allows for continuous testing of the protection device 1 to ensure its proper operation and prevent dormant faults. The test circuit 16 can consist of one or more analog components.

[0071] The second manual control 161 may be in the form of a push button or a lever or a handle or other, and is accessible on the outer surface 18 of the protective device 1 by a user.

[0072] In [Fig.5], the method of protecting equipment E using the protective device 1 comprises step E0 (or E2) and step El, which may be followed by one or more sequences of step E2 and step El, with possibly one or more repetitions of step E3 between these steps.

[0073] According to one embodiment of the invention, the inhibit circuit 15 includes one (or more) other output 152' for controlling the load Z, which can be connected to the load Z. The load Z includes one (or more) input 1520' for receiving a stop command, which is connected to the other control output(s) 152'. The presence of the prescribed activation signal SI on the activation input 151, which moves the trigger 153 to the first position PI, causes a stop command signal S4 for the load Z to be sent to the other control output 152'. The presence of the control signal S4 on the other control output 152' causes the load Z to stop or to disconnect the load Z from the equipment E.Load Z can be stopped by disconnecting the equipment E from the load Z using internal switches (e.g., contactors) within the load Z. These switches are controlled by the presence of the stop command signal S2 on the receiving input(s) 1520'. This protects the equipment E from overvoltages, particularly when the load Z is an active load capable of feeding energy back to the equipment E. The stop command signal S4 for load Z disconnects the load Z to stop the energy supply to it. The load Z can be a controllable load via its receiving input(s) 1520' and can, in some cases, store energy, such as mechanical energy (e.g., a rotating mechanical part) or electrical energy (e.g., an electric motor). The control output 152' can consist of two conductors. .

[0074] According to one embodiment of the invention, the abnormal voltage detection circuit 13 and the inhibition circuit 15 are provided in the same housing 10.

[0075] According to one embodiment of the invention, the test circuit 16 can also be provided in the housing 10.

[0076] According to one embodiment of the invention, the power supply circuit 17 can also be provided in the housing 10.

[0077] According to one embodiment of the invention, the power bypass circuit 14 may also be provided, in whole or in part, within the housing 10. For example, the power switch 142 may be provided within the housing 10, and the first resistor 141 may be provided outside the housing 10 (due to the possibility of a large amount of energy being dissipated by the ohmic effect through the first resistor 141). In another example, the power switch 142 and the first resistor 141 may be provided within the housing 10.

[0078] Of course, the embodiments, features, possibilities and examples described above can be combined with each other or selected independently of each other.

Claims

1. Demands Device (1) for protecting equipment (E) to be powered by a high-voltage DC bus (B), the protective device (1) comprising a first terminal (11) for connection to a first conductor (B1) of the bus (B) and a second terminal (12) for connection to a second conductor (B2) of the bus (B), the first conductor (B1) and the second conductor (B2) being intended to connect the equipment (E) to a high-voltage DC power supply source (S) intended to apply between them a high-voltage DC (HVDC) supply voltage to the equipment (E) having a nominal value (HVDCN0M) of DC supply voltage, characterized in that the protective device (1) further comprises: an inhibition circuit (15), intended to disconnect the high-voltage DC power supply source (S), the inhibition circuit (15) comprising an activation input (151), at least one control output (152) for the high-voltage DC power supply source (S), a trigger (153) and a first manual control (154) disposed on an external surface (18) of the protection device (1), the trigger (153) being configured to assume and maintain, in response to a prescribed activation signal (SI) on the activation input (151), a first position (PI), which causes a shutdown control signal (S2) to be sent to the high-voltage DC power supply source (S) on the at least one control output (152), the trigger (153) being connected to the first manual control (154),which is configured such that the actuation of the first manual control (154) moves the trigger (153) from the first position (PI) to a second position (P2) without causing the shutdown control signal (S2) from the high DC voltage supply source (S) to be sent to at least one control output (152), an abnormal voltage (VB) detection circuit (13), which is connected between the first terminal (11) and the second terminal (12), which has an activation output (131) connected to the activation input (151) and which is configured to send the prescribed activation signal (SI) on the output (131) of activation, when a voltage (VB) greater than a first prescribed threshold (VMax) of DC voltage, greater than the nominal value (HVDCN0M) of DC supply voltage of the high DC voltage (HVDC) supply, is detected between the first terminal (11) and the second terminal (12).

2. Device according to claim 1, characterized in that the protection device (1) comprises a power bypass circuit (14) connected between the first terminal (11) and the second terminal (12).

3. Device according to claim 2, characterized in that the power bypass circuit (14) comprises at least one first resistor (141) and at least one power switch (142), which are in series between the first terminal (11) and the second terminal (12), the power switch (142) having a control input (143) connected to the activation output (131) and being configured to take a connection state of the first resistor (141) between the first terminal (11) and the second terminal (12) in the case where the prescribed activation signal (SI) is present on the control input (143) and to take a disconnection state of the first resistor (141) between the first terminal (11) and the second terminal (12) in the case where the prescribed activation signal (SI) is absent on the control input (143).

4. Device according to claim 3, characterized in that the power switch (142) comprises at least one transistor (144).

5. A device according to any one of the preceding claims, characterized in that the abnormal voltage detection circuit (13) comprises a resistive voltage divider bridge (132) having at least a second resistor (133) and at least a third resistor (134), which are connected in series between the first terminal (11) and the second terminal (12), and a voltage comparator (135), which is connected in parallel with at least a third resistor (134) and which is configured to compare the voltage (V3) in parallel with at least a third resistor (134) to a prescribed reference voltage (VREF), equal to a prescribed divisor factor multiplied by the first prescribed threshold (VMAx) of DC voltage, the prescribed divider coefficient being equal to the resistive value (R3) of at least one third resistor (134), divided by the sum of the resistive value (R2) of at least one second resistor (133) and the resistive value (R3) of at least one third resistor (134), the voltage comparator (135) being configured to send the prescribed activation signal (SI) on the activation output (131), in the case where the voltage (V3) in parallel with at least one third resistor (134) is greater than the prescribed reference voltage (Vref).

6. Device according to any one of the preceding claims, characterized in that the trigger (153) comprises a bistable relay (1530) having as stable states only the first position (PI) and the second position (P2).

7. Device according to any one of the preceding claims, characterized in that the protection device (1) comprises a power supply circuit (17), configured to supply power from the first terminal (11) and the second terminal (12) to the abnormal voltage (VB) detection circuit (13) and / or the inhibition circuit (15).

8. A device according to any one of the preceding claims, characterized in that the protective device (1) comprises a circuit (16) for testing the sending of the activation signal (SI) prescribed by the abnormal voltage (VB) detection circuit (13), the test circuit (16) comprising a second manual control (161) disposed on the outer surface (18) of the protective device (1) and at least one external indicator (162) disposed on the outer surface (18) of the protective device (1), the external indicator (162) being configured to send a first voltage presence signal to the outside, when a voltage (VB) less than or equal to the first prescribed threshold (Vmax) of DC voltage is present between the first terminal (11) and the second terminal (12),the second manual control (161) being configured such that the actuation of the second manual control (161) causes a test of the sending of the activation signal (SI) prescribed by the abnormal voltage (VB) detection circuit (13), the sending by, the external indicator (162) of the first signal of presence of voltage to the outside in the case where the prescribed activation signal (SI) has not been sent by the abnormal voltage detection circuit (13) (VB) and the absence of sending by the external indicator (162) of the first signal of presence of voltage to the outside in the case where the prescribed activation signal (SI) has been sent by the abnormal voltage detection circuit (13) (VB).

9. Device according to any one of the preceding claims, characterized in that the inhibition circuit (15) comprises at least one other control output (152') of a load (Z) intended to be connected to the equipment (E), the first position (PI) of the trigger (153) causing the sending of a stop command signal (S4) of the load (Z) on the other control output (152').

10. A method for protecting equipment (E) to be supplied by a high-voltage DC bus (B) using the protective device (1) according to any one of the preceding claims, the first terminal (11) of which is connected to the first conductor (B1) of the bus (B) and the second terminal (12) of which is connected to the second conductor (B2) of the bus (B), the first conductor (B1) and the second conductor (B2) connecting the equipment (E) to a high-voltage DC supply source (S) intended to apply between them a high-voltage DC (HVDC) supply to the equipment (E) having a nominal value (HVDCN0M) of DC supply voltage, characterized in that the method further comprises the following steps: actuation (E0,E2) of the first manual command (154) to move the trigger (153) from the first position (PI) to the second position (P2) without causing the sending of the stop command signal (S2) from the high DC voltage supply source (S) on at least one control output (152), measurement (El) of the voltage (VB) between the first terminal (11) and the second terminal (12) by the abnormal voltage (VB) detection circuit (13), which sends the prescribed activation signal (SI) on the activation output (131) connected to the activation input (151), in the case where the voltage (VB) between the first terminal (11) and the, second terminal (12) is greater than the first prescribed threshold (Vmax) of DC voltage, greater than the nominal value (HVDCNOm) of DC supply voltage of the high DC voltage (HVDC) supply, in response to the fact that the prescribed activation signal (SI) is present (E2) on the activation input (151), the trigger (153) moves (El) from the second position (P2) to the first position (PI), which causes the shutdown control signal (S2) from the high DC voltage supply source (S) to be sent (E2) to at least one control output (152) connected to the high DC voltage supply source (S).

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