Power supply system with start-up power source

Abstract

The present invention relates to a power supply system (100) comprising: - a power supply (102); - a main power source (108); - a DC-DC converter (110); - a first switch (114) between the DC-DC converter (110) and the power supply (102); - a start-up power source (118); - a second switch (122) between the start-up power source (118) and the power supply (102); and - a control device (126) configured such that, when supplied with power, with the first switch (114) being open and the second switch (102) being closed such that the power supply (102) is supplied with the start-up DC voltage (V2): the control device detects when the converted DC voltage (V1') reaches a predefined threshold and, in response, closes the first switch (114) and opens the second switch (122) so that the power supply (102) is supplied with the converted main DC voltage (V1'). The power supply system (100) further comprises a short-circuit detection system (128) configured to detect a short circuit of the second switch (122) and, in response, open the first switch (114).

Description

Description TITLE: POWER SUPPLY SYSTEM WITH STARTING POWER SOURCE Technical field of the invention

[0001] The present invention relates to an electrical power supply system with a starting electrical source, a method for securing such a system and a mobility device comprising such a system.

[0002] A mobility device is, for example, a motorized land vehicle, a train, an aircraft, or a drone. A motorized land vehicle is, for example, a car, a motorcycle, a motorized bicycle, or a motorized wheelchair. Technological background

[0003] A power supply system of the type comprising: a power supply designed to be supplied by a direct current voltage and, when supplied, to supply at least one electrical device; a main power source designed to supply a main direct current voltage; a DC-DC converter designed to be supplied by the power supply and, when supplied, to convert the main direct current voltage into a converted main direct current voltage; a first switch between the DC-DC converter and the power supply, designed, when closed, to supply the converted direct current voltage to the power supply to supply the latter; a starting power source designed to supply a starting DC voltage;a second switch between the starting power source and the power supply, designed, when closed, to provide the starting DC voltage to the power supply to power the latter; and; a control device designed to be powered by the power supply and, when powered, with the first switch open and the second switch closed so that the power supply is supplied by the DC starting voltage: • detect when the converted DC voltage reaches a predefined threshold, and • In response, close the first switch and open the second switch so that the power supply is powered by the converted main DC voltage.

[0004] Thus, two power sources are used to supply the power supply, but at different times: first, the starting power source when the DC-DC converter is not operational, and then the main power source to implement a looped power supply. The drawback of the previous power supply system is that if the second switch fails and shorts out, there is a risk of a connection being established between the two power sources.

[0005] It may therefore be desirable to provide an electrical power supply system that makes it possible to overcome at least some of the aforementioned problems and constraints. Summary of the invention

[0006] The invention achieves this according to a first aspect by means of a power supply system comprising: a power supply designed to be supplied by a direct current voltage and, when supplied, to supply at least one electrical device; a main power source designed to supply a main direct current voltage; a direct-to-direct converter designed to be supplied by the power supply and, when supplied, to convert the main direct current voltage into a converted main direct current voltage; a first switch between the direct-to-direct converter and the power supply, designed, when closed, to supply the converted direct current voltage to the power supply to supply the latter; a starting power source designed to supply a DC starting voltage; a second switch between the starting power source and the power supply, designed, when closed, to supply the DC starting voltage to the power supply to power the latter; and a control device designed to be powered by the power supply and, when powered, with the first switch open and the second switch closed, so that the power supply is supplied with the DC starting voltage: • detect when the converted DC voltage reaches a predefined threshold, and • in response, close the first switch and open the second switch so that the power supply is supplied by the main converted DC voltage, the power supply system being characterized in that it further comprises a short-circuit detection system designed to detect a short circuit of the second switch and, in response, open the first switch.

[0007] Thus, thanks to the invention, the main power source is disconnected, so that only the starting power source supplies the power supply. In addition to reducing the risk of a connection between the two power sources, this allows the power supply to continue operating, thereby ensuring the continuity of operation of the electrical devices powered by the power supply.

[0008] The invention may further include one or more of the following optional features, in any technically feasible combination.

[0009] Optionally, the short-circuit detection device includes: a first voltage and / or current sensor, placed at the output of the second switch and designed to provide a first measurement to the control device; and the control device which is then designed to detect a short circuit of the second switch from the first voltage measurement and, in response, to open the first switch.

[0010] Optionally, the short-circuit detection device also includes: a short-circuit detection module separate from the control device; and a second voltage and / or current sensor, placed at the output of the second switch and designed to provide a second measurement to the short-circuit detection module; the short-circuit detection module being designed to detect a short circuit of the second switch from the second measurement and, in response, to open the first switch.

[0011] Optionally, the control device is also designed to selectively transmit an open command and a close command to the first switch, and the short-circuit detection module is designed to transmit an open command to the first switch, the power supply system further comprising a control combination module designed to give priority to the first switch for the open command over the close command.

[0012] Optionally, the control device is also designed to transmit a diagnostic command to the short-circuit detection module, so that the latter enters a diagnostic mode and transmits a test measurement to the short-circuit detection module instead of the second measurement, this test measurement being designed to simulate a short circuit of the second switch, and the short-circuit detection module in diagnostic mode is designed, in response to the test measurement, not to command the first switch and instead transmit, to the control device, a status message allowing the control device to verify that the short-circuit detection module has detected a short circuit from the test measurement.

[0013] Optionally, the control device is also designed to check whether the first switch is open when the second switch is closed.

[0014] Optionally, the control device also detects when the DC voltage reaches a predefined threshold, corresponding to the minimum supply voltage of the power supply.

[0015] For example, the minimum supply voltage of the power supply can be 8V, or for example 9V.

[0016] A mobility device comprising an electrical power supply system according to the invention is also proposed.

[0017] A method for securing an electrical power supply system is also proposed, comprising: a power supply designed to be supplied by a direct current voltage and, when supplied, to supply at least one electrical device; a main power source designed to supply a main direct current voltage; a DC-DC converter designed to be supplied by the power supply and, when supplied, to convert the main direct current voltage into a converted main direct current voltage; a first switch between the DC-DC converter and the power supply, designed, when closed, to supply the converted direct current voltage to the power supply to supply the latter; a starting power source designed to supply a starting DC voltage;a second switch between the starting power source and the power supply, designed, when closed, to provide the starting DC voltage to the power supply to power the latter; and a control device designed to be powered by the power supply and, when powered, with the first switch open and the second switch closed so that the power supply is supplied with the starting DC voltage; • detect when the converted DC voltage reaches a predefined threshold, and • In response, close the first switch and open the second switch so that the power supply is powered by the converted main DC voltage; the safety procedure being characterized in that it comprises: a detection of a short circuit of the second switch and, in response, an opening of the first switch. Brief description of the figures

[0018] The invention will be better understood with the aid of the following description, given solely by way of example and made with reference to the accompanying drawings in which: Figure 1 is a functional diagram of an example of a power supply system according to the invention; Figure 2 is a block diagram of a method for starting the power supply system of Figure 1; Figure 3 reproduces Figure 1, with the unactivated parts shown in dashed lines, during an activation step of a power source for starting the power supply system; Figure 4 reproduces Figure 1, with the unactivated parts shown in dashed lines, during a start-up step of a power supply of the power supply system; Figure 5 reproduces Figure 1, with the unactivated parts shown in dashed lines.During a start-up step of a DC-DC converter and a power supply system control device, Figure 6 reproduces Figure 1, with inactive parts shown as dashed lines; during a step of supplying a converted DC voltage from the DC-DC converter, Figure 7 reproduces Figure 1, with inactive parts shown as dashed lines; during a step of detecting the converted DC voltage and switching from the start-up voltage to the converted DC voltage to supply the power supply, Figure 8 is a block diagram of a method for securing the power supply system of Figure 1; Figure 9 reproduces Figure 1, with inactive parts shown as dashed lines; during a step of detecting a short circuit in a switch of the power supply system providing the starting voltage to the power supply device, Figure 10 reproduces Figure 1, with the unactivated parts shown as dashed lines, during a step, in response to the detection of the short circuit, of opening another switch to disconnect the power supply from the converted DC voltage, Figure 11 is a block diagram of a diagnostic process of a short circuit detection module of the power supply system of Figure 1, and Figure 12 reproduces Figure 1, with the unactivated parts shown as dashed lines, during the diagnostic process. Detailed description of the invention

[0019] With reference to Figure 1, an example of a 100 power supply system according to the invention will now be described.

[0020] The power supply system 100 includes, firstly, a power supply 102. This power supply 102 is designed to be supplied by a DC input voltage, for example, between 8 V and 48 V. When supplied, this power supply 102 is designed to provide at least one DC supply voltage to power at least one electrical device 104, 106. Preferably, the DC supply voltage(s) are lower than the DC input voltage, for example, less than 12 V. For example, the power supply 102 is designed to provide a DC supply voltage of 5 V and / or a DC supply voltage of 3.3 V. In the example shown, the 5 V supply voltage powers the electrical device 104 and the 3.3 V supply voltage powers the electrical device 106.

[0021] The power supply system 100 further includes a main power source 108 designed to provide a main DC voltage V1 and a DC-DC converter 110 designed to convert the main DC voltage V1 into a converted DC voltage V1' intended to power the power supply.

[0022] For example, the main power source 108 includes a battery. Also, for example, the main DC voltage V1 is between 48 V and 800 V. For example, the main voltage V1 is 48 V, 400 V, or 800 V.

[0023] Preferably, the DC-DC converter 110 is a step-down converter, so that the converted DC voltage VT is lower than the main DC voltage V1. The converted DC voltage VT is, for example, between 12 V and 48 V.

[0024] The power supply system 100 may also include a first electrical network 112 supplied by the converted direct current voltage VT.

[0025] The DC-DC converter 110 is designed to convert the voltage V1 to the voltage VT when powered by the power supply 102. In particular, the power supply 102 allows, for example, the control of the switching switches of the DC-DC converter 110. The DC-DC converter 110 is therefore designed to receive a DC supply voltage provided by the power supply 102, for example the 5V supply voltage as in the illustrated example.

[0026] The power supply system 100 further includes a first switch 114 between the DC-DC converter 110 and the power supply 102, for example, between the first power network 112 and the power supply 102. The first switch 114 is designed, when closed, to supply the converted DC voltage VT to the power supply 102. When open, the first switch 114 is designed to disconnect the power supply from the converted DC voltage VT. Preferably, the first switch 114 is normally open, that is, it is open in the absence of a command.

[0027] The power supply system 100 may further include a diode 116 between the power supply 102 and the first switch 114, conducting towards the power supply 102 (cathode connected to the power supply 102).

[0028] Based on the above, it is necessary to provide elements for the start-up, due to the loop between the power supply 102 and the DC-DC converter 110: the power supply 102 needs the DC-DC converter 110 to operate and the DC-DC converter 110 needs the power supply 102 to operate.

[0029] Thus, the power supply system 100 further includes a continuous starting power source 118 designed to provide a continuous starting voltage V2.

[0030] The power supply system 100 may also include a second power network 120 supplied by the starting DC voltage V2.

[0031] The power supply system 100 further includes a second switch 122 between the starting power source 118 and the power supply 102, for example between the second power network 120 and the power supply 102.

[0032] The second switch 122 is designed, when closed, to supply the DC starting voltage V2 to the power supply 102. When open, the second switch 122 is designed to disconnect the power supply 102 from the DC starting voltage V2. Preferably, the second switch 122 is normally closed, meaning it is closed when no command is received.

[0033] The power supply system 100 may further include a diode 124 between the power supply 102 and the second switch 114, conducting towards the power supply 102 (cathode connected to the power supply 102).

[0034] To control the first switch 114 and the second switch 122, the power supply system 100 further includes a control device 126, for example a microcontroller, designed to be powered by the power supply 102. In particular, after startup, the control device 126 is designed to close the first switch 114 and open the second switch 114 so that the power supply 102 is supplied with the converted DC voltage VT and disconnected from the starting voltage V2. However, if the second switch 122 fails, causing it to short-circuit, the starting power supply 118 and the main power supply 108 could become connected to each other.

[0035] To avoid this, the power supply system 100 further includes a short-circuit detection system 128 designed to detect a short circuit in the second switch 122 and, in response, open the first switch 114. Thus, not only is a connection between the starting DC voltage V2 and the converted DC voltage avoided, but also the power supply 102 continues to be supplied by the starting voltage V2, allowing the devices 104, 106, 110 that the power supply 102 supplies to continue to operate.

[0036] For example, the short-circuit detection system 128 includes a first voltage and / or current sensor 130, placed at the output of the second switch 122 (i.e., between the second switch 122 and the power supply 102) and designed to provide a first voltage and / or current measurement M1 to the control device 126. The short-circuit detection system 128 further includes the control device 126 which is then designed to detect a short circuit of the second switch 122 from the first voltage and / or current measurement M1 and, in response, to open the first switch 114.

[0037] For example, the short-circuit detection system 128 includes a second voltage and / or current sensor 132, located at the output of the second switch 122 (i.e., between the second switch 122 and the power supply 102) and designed to provide a second voltage and / or current measurement M2. The short-circuit detection system 128 further includes a short-circuit detection module 134 to which the second measurement M2 is provided. The short-circuit detection module 134 is separate from the control device 126. The short-circuit detection module 134 is designed to detect a short circuit in the second switch 122 based on the second measurement M2 and, in response, to open the first switch 114. The short-circuit detection module 134 is, for example, designed to be powered by the power supply 102.

[0038] Preferably, the short-circuit detection system 128 incorporates both of the preceding solutions to achieve redundancy. In this case, the control device 126 and the short-circuit detection module 134 can be of ASILB level and, thanks to the redundancy, the short-circuit detection system 128 as a whole can achieve ASIL D level.

[0039] In this case, the power supply system 100 preferably includes a control combination module 136 designed to combine commands transmitted by the control device 126 and the short-circuit detection module 134, as will be explained later.

[0040] Furthermore, the power supply system 100 includes a third voltage and / or current sensor 138, located at the input of the first switch 114 (i.e., between the DC-DC converter 110 and the first switch 114) and designed to provide a third voltage and / or current measurement M3, as well as a fourth voltage and / or current sensor 140, located at the output of the first switch 114 (i.e., between the first switch 114 and the power supply). electrical 102) and designed to provide a fourth M4 measurement of voltage and / or current.

[0041] With reference to Figure 2, an example of a starting procedure 200 for the power supply system 100 will now be described.

[0042] Initially, the power supply 102 is switched off, so the DC-DC converter 110, the electrical devices 104 and 106, the control device 126, and the short-circuit detection module 134 are also switched off. Furthermore, the starting power supply 118 is deactivated.

[0043] During a step 202 (figure 3), the starting power source 118 is activated and provides the starting DC voltage V2.

[0044] During a step 204 (figure 4), as the second switch 122 is closed, for example because it is normally closed and no command is being sent to it, the DC starting voltage V2 is supplied to the power supply 102 which turns on.

[0045] During step 206 (Figure 5), the power supply 102 is switched on and provides the supply voltage(s). Thus, the electrical devices 104, 106 switch on, as well as the DC-DC converter 110, the control device 126 and the short-circuit detection module 134.

[0046] During a step 208 (figure 6), the DC-DC converter 110 is switched on and supplies the converted DC voltage VT up to the first switch 114. During this step 208, the control device 126 receives the measurement M3, from which the control device 126 detects that the converted DC voltage VT reaches a predefined threshold, for example between 12 V and 48 V, or being the minimum supply voltage of the power supply 102, for example being between 8 V and 9 V.

[0047] During step 208, the control device 126 can also preferably diagnose the first switch 114 to verify that it is indeed open, and therefore, in particular, that it does not have a fault causing it to behave as a short circuit. For this purpose, when sensors 138 and 140 are voltage sensors, the control device 126 can, for example, verify that the voltage measurement M4 is lower than the voltage measurement M3. When sensor 138 or sensor 140 is a current sensor, the device command 126 can for example verify that the current measurement M3 or the current measurement M4 is substantially zero.

[0048] If the first switch 114 is not detected as open and is therefore faulty, the safety of the power supply 100 cannot be guaranteed. It may then be decided not to switch on the DC-DC converter 110. Alternatively, it may be decided to open switch 122.

[0049] During step 210 (Figure 7), upon detection that the converted DC voltage VT reaches the predefined value and, preferably, that the first switch 114 is not faulty, the control device 126 closes the first switch 114 and opens the second switch 122 so that the power supply 102 is supplied with the converted DC voltage VT. For example, the control device 126 sends a CLOSE command to the first switch 114 and an OPEN command to the second switch 122. Preferably, the opening of the second switch 122 occurs quickly after the closing of the first switch 114, for example, less than 10 ps after, so that the two switches 114 and 122 do not both remain closed for too long.

[0050] With reference to Figure 8, an example of a safety procedure 800 for the electrical power supply system 100 will now be described.

[0051] Initially, the 100 power supply system is as shown in Figure 7.

[0052] During step 802 (figure 9), the second switch 122 fails and short-circuits.

[0053] During a step 804 (figure 9), the control device 126 detects the short circuit of the second switch 122 from the first measurement M1.

[0054] During a step 806 (figure 10), in response to the detection of the short circuit of the second switch 122, the control device 126 opens the first switch 114, for example by transmitting an open command OPEN114 to the first switch 114 or by not transmitting any command when the first switch 114 is normally open.

[0055] In parallel with steps 804 and 806, during a step 808 (figure 9), the short-circuit detection module 134 detects the short circuit of the second switch 122 from the second measurement M2.

[0056] During a step 810 (figure 10), in response to the detection of the short circuit of the second switch 122, the short circuit detection module 134 opens the first switch 114, for example by transmitting an open command OPEN to the first switch 114.

[0057] Commands from the control device 126 and the short-circuit detection module 134 to the first switch 114 pass through the control combination module 136. This module is designed to prioritize an open command over a close command. Thus, if the control device 126 fails and continues to transmit the CLOSE command following a short circuit in the second switch 122, it is the OPEN command from the short-circuit detection module 134 that will be transmitted by the control combination module 136 to the first switch 114. For example, if open commands are executed using the logic value "0" and close commands using the logic value "1", the control combination module 136 could, for example, be an OR logic gate.

[0058] With reference to Figure 11, an example of diagnostic procedure 1100 of the short-circuit detection module 134 will now be described.

[0059] Initially, the 100 power supply system is as shown in Figure 7.

[0060] During a step 1102 (figure 12), the control device 126 transmits a DIAG diagnostic command to the short-circuit detection module 134.

[0061] During step 1104, in response, the short-circuit detection module 134 configures itself to disable sending commands to the first switch 114.

[0062] During step 1106 (Figure 12), the control device 126 transmits a test measurement TEST instead of the second measurement M2. This test measurement TEST is designed to simulate the second measurement M2 that the second sensor 132 would send in the event of a short circuit in the second switch 122.

[0063] During step 1108 (Figure 12), the short-circuit detection module 134 transmits a STATE message to the control device 126, allowing the control device 126 to verify that the short-circuit detection module 134 detected the simulated short circuit and therefore functions as expected. However, due to its reconfiguration in step 1104, the short-circuit detection module 134 does not transmit an opening command to the first switch 114 in response to the test measurement TEST.

[0064] In conclusion, it should also be noted that the invention is not limited to the embodiments described above. Indeed, it will be apparent to those skilled in the art that various modifications can be made to the embodiments described above, in light of the information just provided.

[0065] In the detailed presentation of the invention given above, the terms used shall not be interpreted as limiting the invention to the embodiments set forth in this description, but shall be interpreted as including all equivalents which can be foreseen by a person skilled in the art by applying their general knowledge to the implementation of the teaching which has just been disclosed to them.

Claims

Demands [1] Power supply system (100) comprising: a power supply (102) designed to be supplied by a direct current electrical voltage and, when supplied, to supply at least one electrical device (104, 106, 110, 126); a main power source (108) designed to supply a main direct current voltage (V1); a direct-to-direct converter (110) designed to be supplied by the power supply (102) and, when supplied, to convert the main direct current voltage (V1) into a converted main direct current voltage (VT); a first switch (114) between the direct-to-direct converter (110) and the power supply (102), designed, when closed, to supply the converted direct current voltage (VT) to the power supply (102) to supply the latter; a starting power source (118) designed to supply a starting direct current voltage (V2);a second switch (122) between the starting power source (118) and the power supply (102), designed, when closed, to provide the starting DC voltage (V2) to the power supply (102) to power the latter; and a control device (126) designed to be powered by the power supply (102) and to, when powered, with the first switch (114) open and the second switch (122) closed so that the power supply (102) is powered by the starting DC voltage (V2):; • detect when the converted DC voltage (VT) reaches a predefined threshold, and • in response, close the first switch (114) and open the second switch (122) so that the power supply (102) is supplied by the main converted DC voltage (VT); the power supply system being characterized in that it further comprises a short-circuit detection system (128) designed to detect a short circuit of the second switch (122) and, in response, open the first switch (114). [2] Power supply system (100) according to claim 1, wherein the short-circuit detection device (128) comprises: a first voltage and / or current sensor (130), located at the output of the second switch (122) and designed to provide a first measurement (M1) to the control device (126); and the control device (126) which is then designed to detect a short circuit of the second switch (112) from the first voltage measurement (M1) and, in response, to open the first switch (114). [3] Power supply system (100) according to claim 1 or 2, wherein the short-circuit detection device (128) comprises: a short-circuit detection module (134) separate from the control device (126); and a second voltage and / or current sensor (132), placed at the output of the second switch (122) and designed to provide a second measurement (M2) to the short-circuit detection module (134); the short-circuit detection module (134) being designed to detect a short circuit of the second switch (122) from the second measurement (M2) and, in response, to open the first switch (114). [4] Power supply system (100) according to claims 2 and 3 sockets together, wherein the control device (126) is designed to selectively transmit an open command (OPEN) and a close command (CLOSE114) to the first switch (114), and wherein the short-circuit detection module (134) is designed to transmit an open command (OPEN114) to the first switch (114), the power supply system (100) further comprising a control combination module (136) designed to allow the first switch (114) to pass the open command (OPEN114) in priority over the close command (CLOSE114). [5] Power supply system (100) according to claims 2 and 3 taken together or claim 4, wherein the control device (126) is designed to transmit a diagnostic command (DIAG) to the short-circuit detection module (134), causing the latter to enter a diagnostic mode and to transmit to the short-circuit detection module (134) a test measurement (TEST) in place of the second measurement (M2), this test measurement (TEST) being designed to simulate a short circuit of the second switch (122), and wherein the short circuit detection module (134) in diagnostic mode is designed to, in response to the test measurement (TEST) not to control the first switch (114) and instead transmit to the control device (126) a state message (STATE) enabling the control device (126) to verify that the short circuit detection module (134) has detected a short circuit from the test measurement (TEST). [6] Power supply system (100) according to any one of claims 1 to 5, wherein the control device (126) is designed to, when the second switch (122) is closed, check whether the first switch (114) is open. [7] Mobility device comprising an electrical power supply system (100) according to any one of claims 1 to 5. [8] Method for making safe (800) an electrical power supply system (100) comprising: a power supply (102) designed to be supplied by a direct current electrical voltage and, when supplied, to supply at least one electrical device (104, 106, 110, 126); a main power source (108) designed to supply a main direct current voltage (V1); a direct-to-direct converter (110) designed to be supplied by the power supply (102) and, when supplied, to convert the main direct current voltage (V1) into a converted main direct current voltage (VT); a first switch (114) between the direct-to-direct converter (110) and the power supply (102), designed, when closed, to supply the converted direct current voltage (VT) to the power supply (102) to supply the latter; a starting power source (118) designed to supply a starting direct current voltage (V2);a second switch (122) between the starting power source (118) and the power supply (102), designed, when closed, to provide the starting DC voltage (V2) to the power supply (102) to power the latter; and; a control device (126) designed to be powered by the power supply (102) and, when powered, to have the first switch (114) open and the second switch (102) closed so that the power supply (102) is supplied by the DC starting voltage (V2): • detect (208) when the converted DC voltage (VT) reaches a predefined threshold, and • in response, close (210) the first switch (114) and open the second switch (122) so that the power supply (102) is supplied by the main converted DC voltage (VT); the safety method (800) being characterized in that it comprises: a detection (804, 808) of a short circuit of the second switch (122) and, in response, an opening (806, 810) of the first switch (114).

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