Device for controlling the precharging of a bulk capacitor and for detecting a fault in a DC current circuit

Abstract

The utility model relates to a device for controlling pre-charging of a bulk capacitor and for detecting a fault in a DC current circuit, and a DC current circuit. The present description relates to an apparatus for controlling pre-charging of a mass capacitor and for detecting a fault in a DC current circuit comprising a mass capacitor, at least one DC voltage source, and at least a first pre-charge switch coupled to an electrode of the mass capacitor. The device comprises at least a pulse transformer provided with a primary coil and at least a first secondary coil and a second secondary coil, and a circuit for controlling the pre-charging of the bulk capacitor, the circuit being coupled to the primary coil of the pulse transformer. A first secondary coil of the pulse transformer includes a first terminal configured to be coupled to a control input of the first pre-charge switch. A second secondary coil of the pulse transformer is configured to be coupled in parallel with the bulk capacitor.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to French patent application number 24 / 03255, filed on March 29, 2024, entitled “Dispositif de commande de précharge d'une capacitéde stockage et de détection de défaut dans un circuitàcourant continu”, which is incorporated herein by reference to the fullest extent permitted by law. Technical Field

[0003] This disclosure generally relates to the field of DC current circuits. Background Technology

[0004] In a DC current circuit, a bus comprising at least two conductive elements is coupled on one hand to a DC voltage source corresponding to, for example, a battery or the output of a DC / DC or AC / DC converter, and on the other hand to a component of a circuit comprising a capacitive element, typically similar to a large-capacity capacitor. This large-capacity capacitor is coupled in parallel with the DC voltage source via the conductive elements of the bus and at least via a switch that allows the DC voltage source to be coupled to or decoupled from the bus.

[0005] When a switch is turned on or off to couple the bus to a DC voltage source, a significant inrush current flows between the DC voltage source and the large-capacity capacitor. To avoid this inrush current, the large-capacity capacitor can be precharged by conducting a precharge current through it before the switch is turned on. This precharge phase is implemented for a sufficient period of time to achieve the desired precharge voltage across the large-capacity capacitor.

[0006] However, during this pre-charging phase of a large-capacity capacitor, if a fault exists on the bus, such as a short circuit or significant current leakage, then very high currents may circulate in the bus and damage other components of the circuitry coupled to the bus.

[0007] When a thyristor is used as a switch to couple a DC voltage source to a bus during the pre-charging of a large-capacity capacitor, it cannot be turned off in the event of a circuit fault because the current it conducts remains very high. Turning off the thyristor to stop this high-current cycle requires additional circuitry specifically designed for this function.

[0008] A short circuit in a large-capacity capacitor can be detected when an electromechanical relay is used as a switch to couple a DC voltage source to the bus during the pre-charging process. However, this detection is only possible when the relay is closed, leaving a specific time interval before detection during which circulating current may damage circuit components. Furthermore, the opening delay of the electromechanical relay is long and increases over time. Utility Model Content

[0009] A solution is needed that allows the presence of such a fault in a DC current circuit to be detected before performing a pre-charge on a large-capacity capacitor in the absence of a fault.

[0010] One embodiment overcomes all or part of the disadvantages of known solutions and provides an apparatus for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, the DC current circuit including a large-capacity capacitor, at least one DC voltage source, and at least a first pre-charge switch coupled to the electrodes of the large-capacity capacitor. The apparatus includes at least: a pulse transformer having a primary coil and at least a first secondary coil and a second secondary coil; and circuitry for controlling the pre-charging of the large-capacity capacitor, the circuitry being coupled to the primary coil of the pulse transformer. The first secondary coil of the pulse transformer includes a first terminal configured to be coupled to a control input of the first pre-charge switch, and wherein the second secondary coil of the pulse transformer is configured to be coupled in parallel with the large-capacity capacitor.

[0011] In a particular embodiment, the device further includes at least a first power storage capacitor coupled in parallel with the primary winding of the pulse transformer.

[0012] In a particular embodiment, the device further includes: at least a first voltage rectifier diode, the anode of which is coupled to a first terminal of the primary winding of a pulse transformer; and / or at least a first current limiting resistor, the electrodes of which are configured to be coupled to a control input of a first precharge switch.

[0013] In a particular embodiment, the device further includes at least a second Zener diode, the cathode of which is coupled to the cathode of the first voltage rectifier diode and its anode is configured to be coupled to the control input of the first precharge switch.

[0014] In a particular embodiment, the device further includes at least a second protection diode coupled in series with the second-stage coil of the pulse transformer.

[0015] In a particular embodiment, the circuit for controlling the pre-charging of a large-capacity capacitor includes at least: a third diode whose cathode is coupled to a first terminal of the primary coil of a pulse transformer; a first Zener diode whose anode is coupled to the anode of the third diode and whose cathode is coupled to a second terminal of the primary coil of the pulse transformer; and a control switch coupled to the second terminal of the primary coil of the pulse transformer.

[0016] In a particular embodiment, the second terminal of the primary winding of the pulse transformer is coupled to one of the terminals of the secondary winding of the pulse transformer.

[0017] In a particular embodiment, the pulse transformer includes at least a third-stage coil whose terminals are configured to be coupled to a control input of a voltage measuring device or a second precharge switch.

[0018] Another embodiment provides a DC current circuit according to a particular embodiment, the DC current circuit including at least: a DC voltage source; a bus including at least two conductive elements, each conductive element coupled to one of the terminals of the DC voltage source; a capacitive element forming a large-capacity capacitor, each electrode of which is coupled to one of the two conductive elements of the bus; a first pre-charge switch coupled to an electrode of the large-capacity capacitor; and means for controlling the pre-charging of the large-capacity capacitor and for detecting faults in the DC current circuit.

[0019] In a particular embodiment, the DC voltage source includes at least a battery.

[0020] In a particular embodiment, the first precharge switch includes at least a first thyristor, and the control input terminal of the first precharge switch corresponds to the gate of the first thyristor. The circuit also includes at least: a second current-limiting resistor coupled in series with the first thyristor; and a first cut-off switch and a second cut-off switch, each cut-off switch being coupled between one of the terminals of a DC voltage source and one of the electrodes of a large-capacity capacitor. At least one of the first cut-off switch and the second cut-off switch includes a relay.

[0021] In a particular embodiment, one of the first disconnect switch and the second disconnect switch is coupled in parallel with the first thyristor and the second current limiting resistor.

[0022] In a particular embodiment: the DC voltage source includes a totem pole type AC / DC voltage converter, which includes at least two switching transistors and at least two switching thyristors, the gates of which are respectively coupled to a third current-limiting resistor and an optocoupler that are coupled in series with each other to form a first pre-charge switch and a second pre-charge switch; the pulse transformer of the device includes at least a third stage coil; a first terminal of the first stage coil of the pulse transformer of the device is coupled to the input electrode of one of the optocouplers; and a first terminal of the third stage coil of the pulse transformer of the device is coupled to the input electrode of another optocoupler in the optocouplers.

[0023] In a particular embodiment: the DC voltage source includes a Boost PFC type AC / DC voltage converter with a hybrid bridge, the voltage converter including at least two switching diodes and at least two switching thyristors, or at least four switching thyristors, the gate of each switching thyristor being coupled to a third current-limiting resistor and an optocoupler that are coupled in series with each other to form a first precharge switch and a second precharge switch; and the first terminal of the first stage coil of the pulse transformer of the device is coupled to the input electrode of each optocoupler.

[0024] In a particular embodiment: the DC voltage source includes a Boost PFC type AC / DC voltage converter with a diode bridge; and the first precharge switch includes at least a first thyristor, a third current-limiting resistor and an optocoupler coupled in series with each other. Attached Figure Description

[0025] The foregoing features and advantages, as well as other features and advantages, will be described in detail in the remainder of the disclosure of specific embodiments given by way of illustration and not limitation, with reference to the accompanying drawings, in which:

[0026] Figure 1 An example of an implementation of a device for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit is shown schematically.

[0027] Figure 2 An apparatus for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a first embodiment, is schematically shown.

[0028] Figure 3 A simplified timing diagram of the signal obtained in the device according to the first embodiment for controlling the pre-charging of a large-capacity capacitor and for detecting faults in the DC current circuit is shown in the absence of faults in the circuit.

[0029] Figure 4A simplified timing diagram of the signal obtained in the device according to the first embodiment for controlling the pre-charging of a large-capacity capacitor and for detecting faults in the DC current circuit in the event of a fault in the circuit is shown.

[0030] Figure 5 The diagram schematically illustrates a device for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a first variant of the first embodiment.

[0031] Figure 6 A device for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a second variant of the first embodiment, is schematically shown.

[0032] Figure 7 An apparatus for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a second embodiment, is schematically shown.

[0033] Figure 8 An apparatus for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a third embodiment, is schematically shown; and

[0034] Figure 9 An apparatus for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, according to a fourth embodiment, is schematically shown. Detailed Implementation

[0035] Similar features in the various figures are indicated by similar reference numerals. In particular, common structural and / or functional features between the various embodiments may have the same reference numerals and may have the same structure, dimensions, and material properties.

[0036] For clarity, only those steps and elements useful for understanding the described embodiments are shown and described in detail. In particular, the various components (voltage sources, buses, switches, control circuits, transformers, etc.) of the device used for controlling the pre-charging of large-capacity capacitors and fault detection in the DC current circuit are not described in detail. Those skilled in the art will be able to implement these components in detail based on the functional descriptions given herein.

[0037] Unless otherwise indicated, when referring to two elements connected together, it means a direct connection without any intermediate elements other than a conductor; when referring to two elements coupled together, it means that the two elements can be connected or they can be coupled via one or more other elements.

[0038] Unless otherwise indicated, the term "conduction" is used to refer to electrical conduction.

[0039] Throughout the document, the term "fault" used in relation to DC current circuits refers to an electrical fault present in the circuit, such as a short circuit in a large capacitor or significant current leakage.

[0040] Unless otherwise specified, the expressions “approximately,” “around,” “substantially,” and “…about” indicate addition or subtraction of 10%, preferably 5%.

[0041] The following is about Figure 1 An example of an embodiment of a device 100 for controlling the pre-charging of a large-capacity capacitor 1002 and for detecting faults in a DC current circuit 1000 in which the large-capacity capacitor 1002 is located is described.

[0042] Circuit 1000 includes at least one DC voltage source 1004, including, for example, one or more batteries and / or at least one DC / DC or AC / DC converter. However, other types of DC voltage sources may be included in circuit 1000.

[0043] Circuit 1000 also includes a bus for circulating DC current within circuit 1000 and includes at least two conductive elements 1006, each coupled to one of the terminals of source 1004. In the example of the described embodiment, source 1004 is intended to apply a DC voltage to these conductive elements 1006 and deliver DC current circulating through the conductive elements 1006 on the bus.

[0044] Circuit 1000 also includes other electrical components coupled to the bus and forming one or more capacitive electrical elements, which are generally similar to large-capacity capacitor 1002. Each electrode of large-capacity capacitor 1002 is coupled to one of two conductive elements 1006 of the bus of circuit 1000.

[0045] Circuit 1000 also includes at least one pre-charge switch 1008, which is coupled to one of the electrodes of a large-capacity capacitor 1002. Figure 1 In the example, a precharge switch 1008 is included in the source 1004. As a variant, the precharge switch 1008 may be a different element from the source 1004. The precharge switch 1008 may be coupled between a first terminal of the source 1004 and one of the electrodes of the large-capacity capacitor 1002.

[0046] The circuit 1000 also includes a device 100 for controlling the pre-charging of the large-capacity capacitor 1002 and for detecting faults in the circuit 1000.

[0047] The device 100 includes at least one pulse transformer 102, which has a primary coil 104 and at least one first-stage coil 106 and a second-stage coil 108, the primary coil 104 being magnetically coupled to the first-stage coil 106 and the second-stage coil 108. The first-stage coil 106 and the second-stage coil 108 may be similar to or different from each other in terms of the number of windings. The electrical characteristics of the transformer 102 may be selected specifically according to the voltage and current levels that the components of the transformer 102 need to withstand.

[0048] The device 100 also includes circuitry 110 for controlling the pre-charging of a large-capacity capacitor 1002, the circuitry 110 being coupled to the primary coil 104. In the example of the described embodiment, circuitry 110 is designed to apply a pulsed voltage across the primary coil 104 during the pre-charging of the large-capacity capacitor 1002.

[0049] The primary coil 106 includes a first terminal 112 coupled to the control input terminal of the pre-charge switch 1008. Figure 1 In the example, the first terminal 112 of the primary coil 106 is coupled to the control input of the precharge switch 1008 via a voltage rectifier diode 114, the anode of which is coupled to the first terminal 112 and the cathode of which is coupled to the control input of the precharge switch 1008.

[0050] In the example of the described embodiment, device 100 also includes a power storage capacitor 116 coupled in parallel with the primary coil 106 and intended to form a power supply for controlling the precharge switch 1008. Figure 1 In the example, the first terminal 112 of the primary coil 106 is coupled to one of the electrodes of the power storage capacitor 116 via a voltage rectifier diode 114, the power storage capacitor 116 being coupled in parallel with the assembly formed by the primary coil 106 and the voltage rectifier diode 114. Figure 1 In the example, the cathode of the voltage rectifier diode 114 is coupled to one of the electrodes of the power storage capacitor 116, and the anode of the voltage rectifier diode 114 is coupled to the first terminal 112 of the primary winding 106. Given a voltage change across the primary winding 106, when the voltage across the primary winding 106 is positive, the voltage rectifier diode 114 enables the power storage capacitor 116 to be charged with a constant DC voltage.

[0051] The secondary coil 108 is coupled in parallel with the large-capacity capacitor 1002. Figure 1In the example, device 100 also includes a protection diode 118 coupled in series with the secondary coil 108, which prevents the large-capacity capacitor 1002 from discharging through the secondary coil 108 when the large-capacity capacitor 1002 is pre-charged, while allowing current to flow between the large-capacity capacitor 1002 and the secondary coil 108 during the fault presence check phase. Figure 1 In the corresponding specific configuration shown, the cathode of the protection diode 118 is coupled to one of the terminals of the secondary coil 108, and the anode of the protection diode 118 is coupled to one of the electrodes of the large-capacity capacitor 1002. Figure 1 In the example, the large-capacity capacitor 1002 is coupled in parallel with a component formed by the secondary coil 108 and the protection diode 118.

[0052] In this circuit 1000 including device 100, when intended to precharge large-capacity capacitor 1002, for example before connecting source 1004 to the bus, circuit 110 controls transformer 102 such that a non-zero pulse voltage is applied across primary coil 104. In the absence of faults, particularly in the absence of a short circuit across large-capacity capacitor 1002, a first voltage in the form of a non-zero pulse is generated across primary coil 106, and a second voltage in the form of a non-zero pulse is generated across secondary coil 108. The second voltage across secondary coil 108 charges large-capacity capacitor 1002, for example, by a few volts, while the first voltage present across primary coil 106 generates a current that circulates through power storage capacitor 116, thereby increasing the current across the potential difference of power storage capacitor 116. This potential difference across power storage capacitor 116 generates a control current sent to the control input of precharge switch 1008, which, when precharge switch 1008 is turned on, triggers the precharging of large-capacity capacitor 1002.

[0053] However, in the presence of a fault, such as a short circuit across the large-capacity capacitor 1002, although circuit 110 applies voltage to the primary coil 104, the voltage across the secondary coil 108 remains zero. Therefore, the voltage across the primary coil 106 also remains zero. Consequently, no current flows to charge the power storage capacitor 116, and therefore no control current is sent to the control input of the pre-charge switch 1008. Because the pre-charge switch 1008 remains in the off state, pre-charging of the large-capacity capacitor 1002 is not triggered.

[0054] Therefore, transformer 102 performs two functions simultaneously: the primary coil 106 is used to control the conduction state of precharge switch 1008 based on the presence or absence of a fault in circuit 1000, and the secondary coil 108 is used to detect the presence or absence of a fault in circuit 1000.

[0055] The following text is about Figure 2 Examples of a device 100 and a circuit 1000 according to a first embodiment are described. In this first embodiment, the circuit 1000 may be part of or form part of a system for controlling a vehicle battery.

[0056] In a first embodiment, source 1004 includes one or more batteries delivering a DC voltage VBat. For example, the one or more batteries of source 1004 may correspond to one or more batteries of an electric vehicle, wherein the voltage delivered across source 1004 may be approximately 400V or 800V or another value.

[0057] exist Figure 2 In one example, circuit 110 includes at least: a diode 120, the cathode of which is coupled to a first terminal of primary coil 104; a Zener diode 122, the anode of which is coupled to the anode of diode 120 and the cathode of which is coupled to a second terminal of primary coil 104; and a control switch 124 configured to control voltage pulses applied across primary coil 104.

[0058] Diodes 120 and 122 form a demagnetizing circuit for transformer 102. In the first stage, control switch 124 is closed and current flows through primary coil 104. When primary coil 104 is blocked by opening control switch 124, the power stored in transformer 102 must be depleted. Then, an overvoltage occurs at the terminal of control switch 124 coupled to primary coil 104. Zener diode 122 is used to clamp this overvoltage and protect primary coil 104. During this stage, diode 120 allows current to flow between Zener diode 122 and primary coil 104.

[0059] exist Figure 2 In the example, control switch 124 includes a MOSFET-type transistor. One of the source or drain electrodes of this transistor can be coupled to a second terminal of the primary coil 104, and the other source or drain electrode of this transistor can be coupled to a reference potential. Figure 2 In the example, this transistor is N-type, and the electrode coupled to the second terminal of the primary coil 104 corresponds to its drain. When a fault exists in circuit 1000, this transistor behaves like a current source (in saturation), but when no fault exists, it behaves like an on / off switch. For example, and depending on the transistor's characteristics, for a voltage VGS of approximately 4V, the current value can be limited to approximately 150mA to 200mA, or for a voltage VGS of approximately 5V, the current value can be limited to approximately 450mA to 500mA.

[0060] exist Figure 2 In the example, a DC voltage VCC is applied to the first terminal of the primary coil 104. Therefore, when the control switch 124 is turned on, this voltage VCC is applied across the primary coil 104. The on or off state of the control switch 124 is controlled by the pulse control signal EN. Figure 2 In the example, the control signal EN is applied to the gate of the transistor forming the control switch 124. Therefore, a voltage VCC is applied to the primary coil 104 at the frequency of the pulse of the control signal EN. For example, the voltage VCC can be equal to 5V, and the frequency of the control signal EN can be equal to 10kHz.

[0061] exist Figure 2 In the example, the second terminal of the first stage coil 106 is coupled to one of the terminals of the second stage coil 108. As a variant, these terminals may not be coupled to each other.

[0062] exist Figure 2 In the example, device 100 also includes a first current-limiting resistor 126 having electrodes coupled to a control input terminal of pre-charge switch 1008. Figure 2 In this circuit, the other electrode of resistor 126 is coupled to the cathode of voltage rectifier diode 114 and one of the electrodes of power storage capacitor 116. The value of this first current-limiting resistor 126 can be selected based on the value of the current sent to the control input of precharge switch 1008. As a variant, device 100 may not include this resistor 126.

[0063] In the example of the described embodiment, the precharge switch 1008 includes at least one thyristor, and the control input of the precharge switch 1008 corresponds to the gate of the thyristor. Alternatively, other types of switches can be used to form the precharge switch 1008, such as, for example, a TRIAC (triode for AC current), a relay, a transistor, etc.

[0064] In addition, Figure 2 In the example of the embodiment shown, circuit 1000 further includes a second current-limiting resistor 1010 coupled in series with pre-charge switch 1008. Figure 2 In the example, it is coupled in series with the anode of the thyristor. This resistor 1010 is designed to limit the current circulating between the source 1004 and the large-capacity capacitor 1002, thereby limiting the pre-charge current of the large-capacity capacitor 1002. For example, the value of the second current limiting resistor 1010 can be equal to 100 ohms. Alternatively, the second current limiting resistor 1010 can be a PTC (positive temperature coefficient) type thermistor.

[0065] In a first embodiment, circuit 1000 further includes a first disconnect switch 1012 and a second disconnect switch 1014, each disconnect switch coupled between one of the terminals of source 1004 and one of the electrodes of large-capacity capacitor 1002. These first disconnect switches 1012 and second disconnect switches 1014 are intended to couple source 1004 to a bus of circuit 1000. To ensure physical disconnection between source 1004 and the bus of circuit 1000, at least one of the first disconnect switches 1012 and second disconnect switches 1014 includes a relay, such as an electromechanical relay. For example, both the first disconnect switch 1012 and the second disconnect switch 1014 may correspond to a relay, or one of the two disconnect switches 1012, 1014 may correspond to a relay, and the other of the two disconnect switches 1012, 1014 may correspond to a semiconductor switch such as a transistor.

[0066] exist Figure 2 In the example, the first disconnect switch 1012 is coupled in parallel with the precharge switch 1008 and the resistor 1010. During the precharge of the large-capacity capacitor 1002, the first disconnect switch 1012 is in an open or closed state, and the second disconnect switch 1014 is in an open or closed state.

[0067] Figure 3 A simplified example of a timing diagram of the signals obtained within the circuit 1000 according to the aforementioned first embodiment is shown when there is no short circuit in the large-capacity capacitor 1002. In this diagram, the signals are shown schematically, and their amplitudes are disproportionate to each other.

[0068] exist Figure 3 During the interval between times t1 and t4, the pulse control signal EN is applied to the control input terminal of circuit 110 (and...). Figure 2 In the example, the gate of the transistor forming the control switch 124 corresponds to this. Since there is no short circuit in the large-capacity capacitor 1002, the pulse voltage across the primary coil 104 causes a non-zero pulse voltage to be generated across the first-stage coil 106 and the second-stage coil 108. This, in turn, generates a pulse current IS2 that circulates from the second-stage coil 108 through the large-capacity capacitor 1002 and increases before being sent to the control input of the pre-charge switch 1008 (corresponding to...). Figure 2 In the example, the amplitude of the control current IG1 is corresponding to the gate of the thyristor forming the pre-charge switch 1008.

[0069] exist Figure 3In the above, time t2 corresponds to the time when the thyristor forming the pre-charge switch 1008 turns on, due to the fact that the current IG1 reaches the value IGT that triggers the thyristor to turn on. Between times t1 and t2, the increase in voltage VC1 across the large-capacity capacitor 1002 is due to the current supplied by the secondary coil 108. Starting from time t2, voltage VC1 increases more significantly because the pre-charge switch 1008 is in the on state and the source 1004 is coupled to the large-capacity capacitor 1002 via resistor 1010 and the pre-charge switch 1008. Starting from time t3, once voltage VC1 exceeds the voltage supplied by the secondary coil 108, current IS2 becomes zero and the large-capacity capacitor 1002 charges to reach the VBat voltage value of the source 1004 at time t5. At time t4, when the control signal EN applied to the control input terminal of the control switch 124 stops because the thyristor forming the pre-charge switch 1008 is in the on state, current IG1 drops to zero. Starting at time t5, the large-capacity capacitor 1002 is precharged, and the source 1004 can be connected to the bus by turning on the first cut-off switch 1012 to limit the loss caused by the resistor 1010 during the steady-state operation of the device 100.

[0070] Figure 4 A simplified example of a timing diagram of a signal obtained within the device 100 according to the aforementioned first embodiment is shown in the event of a short circuit in the large-capacity capacitor 1002. In this diagram, the signals are shown schematically, and their amplitudes are disproportionate to each other.

[0071] like Figure 3 As shown, the pulse control signal EN is applied to the control input of circuit 110 between times t1 and t4. Because there is a short circuit across the large-capacity capacitor 1002, the voltage across the large-capacity capacitor 1002 remains zero. Therefore, the voltage across the secondary coil 108 is also zero, which means the voltage across the primary coil 106 is also zero. Therefore, no control current is sent to the control input of the pre-charge switch 1008, and thus the pre-charge switch 1008 remains in the open state.

[0072] The following is about Figure 5 Examples of device 100 and circuit 1000 according to a first variant of the first embodiment are described.

[0073] In this first variant, device 100 and circuit 1000 include the previously mentioned... Figure 2All elements and components described. The device 100 according to this first variant also includes a second Zener diode 128, the cathode of which is coupled to the cathode of the voltage rectifier diode 114 and one of the electrodes of the power storage capacitor 116, and the anode of which is coupled to the control input of the precharge switch 1008, i.e., the gate of the thyristor forming the precharge switch 1008 in this example.

[0074] This first alternative embodiment can be advantageous in cases where the presence of a short circuit creates a load in parallel with the large-capacity capacitor 1002, resulting in high leakage from circuit 1000 (e.g., around tens of ohms or less). In fact, in the presence of such a short circuit and without the second Zener diode 128, a non-zero voltage can be obtained across each of the secondary coils 106, 108 and across the voltage rectifier diode 114 when a voltage is applied across the primary coil 104. In this case, the amplitude of the voltage obtained across the secondary coils 106, 108 depends particularly on the amplitude of the current circulating through the load formed by the short circuit and on the ratio of the number of windings in the secondary coils 106, 108. A non-zero control current (e.g., a few mA) can then be sent to the control input of the pre-charge switch 1008, which can trigger it to be turned on, thereby triggering the pre-charging of the large-capacity capacitor 1002. When device 100 includes a second Zener diode 128, this control current is blocked by the second Zener diode 128, thereby preventing the precharge switch 1008 from being set to the on state, thereby preventing the precharging of the large-capacity capacitor 1002. The threshold of the second Zener diode 128 depends on the short-circuit leakage current level.

[0075] Previous regarding Figure 2 The different configurations described can be applied to this first variant of the first embodiment.

[0076] The following is about Figure 6 Examples of device 100 and circuit 1000 according to a second variant of the first embodiment are described.

[0077] In this second variant, device 100 and circuit 1000 include the previously mentioned... Figure 2 All elements and components are described, but transformer 102 includes at least one third-stage coil 130, the terminals of which are configured to be coupled to a voltage measuring device. Figure 6 (Not shown in the image), for example, corresponding to a microcontroller. In Figure 6 In the example, the second voltage rectifier diode 132 is coupled to one of the terminals of the third stage coil 130 and blocks the voltage when the voltage of the third stage coil 130 is negative, thereby enabling the voltage measuring device to measure only positive voltages.

[0078] This second variant offers the advantage of allowing the voltage of one of the secondary coils of transformer 102 to be measured in isolation without connecting the voltage measuring device to both the primary coil 106 and the secondary coil 108. In a specific configuration, the third coil 130 can have a similar number of windings as the primary coil 106, allowing the voltage across the third coil 130 to be similar to that obtained across the primary coil 106. Therefore, a measurement of zero (or very low) voltage across the third coil 130 could indicate a short circuit in circuit 1000, particularly a short circuit across the large-capacity capacitor 1002.

[0079] Previous regarding Figure 2 The different configurations described can be applied to this second variant of the first embodiment. Additionally, the first and second alternative embodiments described above can be combined with each other, in which case device 100 includes a second Zener diode 128 and a pulse transformer 102 including at least three secondary coils 106, 108, and 130.

[0080] The following text is about Figure 7 An example of a device 100 and a circuit 1000 according to a second embodiment is described. In this second embodiment, the circuit 1000 may form part of or constitute the power converter.

[0081] In this second embodiment, source 1004 includes a totem-pole type AC / DC voltage converter (AC input voltage at...). Figure 7 The voltage converter (referred to as VAC) includes: at least one first branch comprising two switching transistors 1016, 1018, such as MOS type; and at least one second branch comprising two switching thyristors 1020, 1022. The gates of the two thyristors 1020, 1022 are each coupled to current-limiting resistors 1024, 1026 and optocouplers 1028, 1030, which are coupled in series with each other. In an example of the described embodiment, each component including one of the thyristors 1020, 1022, one of the resistors 1024, 1026, and one of the optocouplers 1028, 1030 forms a precharge switch 1008 configured to be turned on during the precharge of a large-capacity capacitor 1002.

[0082] Alternatively, transistors 1016 and 1018 can be of the IGBT (Insulated Gate Bipolar Transistor) type.

[0083] In this second embodiment, the transformer 102 includes a third-stage coil 130 in addition to the first-stage coil 106 and the second-stage coil 108. The third-stage coil 130 has a first terminal 136 coupled to a second voltage rectifier diode 132. In the described example, the device 100 also includes a second power storage capacitor 134 coupled in parallel with the third-stage coil 130. Figure 7 In the example, the first terminal 136 of the third stage coil 130 is coupled to one of the electrodes of the second power storage capacitor 134 via the second voltage rectifier diode 132, the second power storage capacitor 134 being coupled in parallel with the assembly formed by the third stage coil 130 and the second voltage rectifier diode 132. Figure 7 In the example, the cathode of the second voltage rectifier diode 132 is coupled to one of the electrodes of the second power storage capacitor 134, and the anode of the second voltage rectifier diode 132 is coupled to the first terminal 136 of the third stage coil 130.

[0084] The first terminal 112 of the first stage coil 106 is coupled to the control input terminal of one of the precharge switches 1008 formed by the input electrode of the optocoupler 1028 via the first voltage rectifier diode 114, and the first terminal 136 of the third stage coil 130 is coupled to the control input terminal of another of the precharge switches 1008 formed by the input electrode of the optocoupler 1030 via the second voltage rectifier diode 132.

[0085] The operation of the device 100 and circuit 1000 according to the second embodiment is substantially similar to the operation previously described for the device 100 and circuit 1000 according to the first embodiment. When a short circuit exists in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108, and 130 is zero, and no control current is sent to the input electrodes of the optocouplers 1028 and 1030. When a short circuit does not exist in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108, and 130 is not zero, and a non-zero control current is sent to the input electrodes of the optocouplers 1028 and 1030, thereby triggering the thyristors 1020 and 1022 to turn on via the current flowing through the gates of the thyristors 1020 and 1022, and pre-charging the large-capacity capacitor 1002.

[0086] As a variation of this second embodiment, as in the first variation of the first embodiment described above, device 100 may include a Zener diode, the cathode of which is coupled to the cathode of voltage rectifier diodes 114, 132 and its anode coupled to the input electrode of each of optocouplers 1028, 1030. As in the second variation of the first embodiment described above, pulse transformer 102 may also include a fourth secondary coil, the terminals of which are configured to be coupled to a voltage measuring device.

[0087] The different configurations previously described with respect to the first embodiment can be applied to the device 100 and circuit 1000 according to the second embodiment.

[0088] The following text is about Figure 8 An example of a device 100 and a circuit 1000 according to a third embodiment is described. In this third embodiment, the circuit 1000 may form part of or constitute the power converter.

[0089] In this third embodiment, source 1004 includes a Boost PFC (“Power Factor Correction”) type AC / DC voltage converter with a hybrid bridge, comprising at least two switching diodes 138, 140 and two switching thyristors 1020, 1022. The gates of the two thyristors 1020, 1022 are each coupled to current-limiting resistors 1024, 1026 and optocouplers 1028, 1030 coupled in series with each other. As in the second embodiment described above, each component including one of the thyristors 1020, 1022, one of the resistors 1024, 1026, and one of the optocouplers 1028, 1030 forms a precharge switch 1008 configured to be turned on during the precharge of a large-capacity capacitor 1002.

[0090] As a variant, thyristors can be used instead of switching diodes 138 and 140.

[0091] The first terminal 112 of the primary coil 106 is coupled via a voltage rectifier diode 114 to the control input terminal of the precharge switch 1008 formed by the input electrodes of each of the optocouplers 1028 and 1030. Therefore, the current emanating from the primary coil 106 is intended to form the control current of the precharge switch 1008.

[0092] exist Figure 8In this example, circuit 1000 also includes a MOSFET-type transistor 142, such as transistor 124 similar to that in circuit 110. A pulse control signal EN is applied to the gate of this transistor 142. The source and drain electrodes of this transistor 142 are coupled to the electrodes of the large-capacity capacitor 1002 in such a way that transistor 142 is coupled in parallel with the large-capacity capacitor 1002. Additionally, inductor 144 is coupled to one of the electrodes of the large-capacity capacitor 1002.

[0093] When transistor 142 is turned on, current flows through inductor 144, which accumulates energy. When transistor 142 is turned off, the energy stored in inductor 144 is sent to large-capacity capacitor 1002. By means of regulation via transistor 142, transistor 142 can be controlled in such a way that the supplied current is sinusoidal and in phase with the supplied voltage.

[0094] The operation of the device 100 and circuit 1000 according to the third embodiment is substantially similar to the operation previously described for the device 100 and circuit 1000 according to the first and second embodiments. When a short circuit exists in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108 is zero, and no control current is sent to the input electrodes of the optocouplers 1028, 1030. When a short circuit does not exist in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108 is not zero, thus a non-zero control current is sent to the input electrodes of the optocouplers 1028, 1030, thereby triggering the thyristors 1020, 1022 to be turned on and triggering the pre-charging of the large-capacity capacitor 1002 via the current flowing through the gates of the thyristors 1020, 1022.

[0095] As a variation of this third embodiment, as in the first variation of the first embodiment described above, device 100 may include a Zener diode, the cathode of which is coupled to the cathode of voltage rectifier diode 114 and its anode coupled to the input electrode of each of optocouplers 1028, 1030. As in the second variation of the first embodiment described above, pulse transformer 102 may also include a fourth secondary coil, the terminals of which are configured to be coupled to a voltage measuring device.

[0096] The different configurations previously described with respect to the first and second embodiments can be applied to the device 100 and circuit 1000 according to the third embodiment.

[0097] The following text is about Figure 9 An example of a device 100 and a circuit 1000 according to a fourth embodiment is described. In this fourth embodiment, the circuit 1000 may form part of or form the power converter.

[0098] In this fourth embodiment, source 1004 includes a Boost PFC type AC / DC voltage converter, which includes at least a diode bridge 150 (in Figure 9 In the diagram, the reference numerals for the four switching diodes forming the diode bridge 150 are 138, 140, 146, and 148.

[0099] In this fourth embodiment, the precharge switch 1008, configured to be turned on during the precharge of the large-capacity capacitor 1002, includes a thyristor whose gate forms the control input of the precharge switch 1008 and is coupled to the current limiting resistor 1024 and the optocoupler 1028.

[0100] The other components of the device 100 and circuit 1000 are similar to those previously described with respect to the third embodiment.

[0101] The operation of the device 100 and circuit 1000 according to this fourth embodiment is substantially similar to the operation previously described for the device 100 and circuit 1000 according to the previous embodiments. When a short circuit exists in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108 is zero, and no control current is sent to the input electrode of the optocoupler 1028. When there is no short circuit in the large-capacity capacitor 1002, the voltage across each of the secondary coils 106, 108 is not zero, thus a non-zero control current is sent to the input electrode of the optocoupler 1028, thereby triggering the thyristor forming the charging switch 1008 to be turned on via the current flowing through its gate and triggering the pre-charging of the large-capacity capacitor 1002.

[0102] In all modes, examples, and alternative embodiments, the thyristors or SCRs (“silicon rectifiers”) used to form one or more charging switches 1008 can be replaced by other types of switches such as TRIACs, relays, or transistors.

[0103] In the second, third, and fourth embodiments described above, source 1004 includes an AC / DC converter. As a variation, source 1004 may include a DC / DC converter or a transformer, such as a flyback converter.

[0104] As a variation of an example of an embodiment of the precharge control circuit 110 previously described in various embodiments, the circuit 110 may include a microcontroller and / or a DSP (digital signal processor) to control the primary coil 104 of the pulse transformer 102.

[0105] The values ​​of the different components described above may differ from the examples mentioned earlier, and these values ​​vary in particular depending on the application and operating environment of device 100 and circuit 1000.

[0106] Device 100 enables improved protection of the DC current circuit 1000 by using pulse transformer 102 to detect potential faults in circuit 1000, such as a short circuit in a large-capacity capacitor 1002 caused by one of the secondary coils of transformer 102, and by allowing or disallowing pre-charging of the large-capacity capacitor 1002 after the fault is detected or not detected, and due to one or more other secondary coils of transformer 102. Therefore, short-circuit detection and pre-charge control functions are simultaneously implemented from the same pulse transformer.

[0107] For example, when the thyristor is used as a pre-charge switch, device 100 can prevent the thyristor from turning on, for example, when a short circuit exists in the large-capacity capacitor 1002 or a fault such as leakage exists in the circuit 1000. When the relay is used as a pre-charge switch, device 100 enables short circuit or fault detection to be performed in the circuit 1000 without closing the relay to perform this detection.

[0108] Device 100 allows for rapid detection of short circuits or leakage faults in the DC current circuit 1000. Furthermore, device 100 does not require a circuit dedicated solely to the shutdown of the pre-charge switch.

[0109] Device 100 can be used in battery management systems (or BMS), electric vehicles, or in power conversion structures such as totem pole type and hybrid bridge.

[0110] For example, the equipment is designed for use in the automotive industry. The electrification of automobiles is leading to increasingly higher levels of electronics in vehicles. For instance, the equipment includes thyristors, rectifiers, high-voltage transient voltage suppressor diodes, modules, etc., designed for integration into such vehicles. The automation of driving is also increasing the electronic content in vehicles. For example, the equipment includes high-voltage transient voltage suppressor diodes, electromagnetic discharge protection, and common-mode filters to protect emerging and complex electronic devices from electrical risks.

[0111] For example, the device can be used in industrial applications. More specifically, for example, the device is designed for the development of green energy or for the electrification of infrastructure, such as for charging terminals or for integration with solar energy. For example, the device is designed to be implemented in power and energy circuits, including, for example, 800V or 1200V thyristors, ultrafast and silicon carbide 1200V diodes, transient voltage suppression diodes, and electromagnetic discharge protection. The device can also be used in implementations in data centers and servers. For example, the device includes wide-bandgap materials.

[0112] For example, the device is intended for use in communication equipment or computer and peripheral devices. For example, the device can be used in 5G infrastructure and dedicated data centers. For example, the device includes silicon carbide diodes, Schottky power transistors, electromagnetic discharge protection diodes, and transient voltage suppression diodes. The device can also be used in satellites, for example, including integrated passive devices for radio frequency applications.

[0113] The device can be used with any type of AC / DC or DC / DC converter.

[0114] The described solution can be used to control any type of precharge switch: thyristors, MOSFETs, relays, IGBTs, etc.

[0115] Another embodiment provides a method for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, the DC current circuit including a large-capacity capacitor, at least one DC voltage source, and at least a first pre-charge switch coupled to the electrodes of the large-capacity capacitor. The method uses a pulse transformer having a primary coil and at least a first secondary coil and a second secondary coil, and also uses circuitry for controlling the pre-charging of the large-capacity capacitor, the circuitry being coupled to the primary coil of the pulse transformer. In this method, the first secondary coil includes a first terminal coupled to a control input of the first pre-charge switch, and the second secondary coil is coupled in parallel with the large-capacity capacitor.

[0116] In a particular embodiment, the method includes sending a control signal to the primary coil of a pulse transformer via circuitry for controlling the pre-charging of a large-capacity capacitor. In the absence of a fault in the DC circuit, the method involves generating a voltage at the terminals of the primary and secondary coils and sending a current to the control input of a first pre-charge switch to trigger the pre-charging of the large-capacity capacitor. In the presence of a fault in the DC circuit, the method involves maintaining a zero or very low voltage at the terminals of the primary and secondary coils and keeping the first pre-charge switch in a blocked state, thereby preventing pre-charging of the storage capacity.

[0117] Various embodiments and variations have been described. Those skilled in the art will understand that certain features of these various embodiments and variations can be combined, and other variations will occur to those skilled in the art.

[0118] Finally, based on the functional indications given above, the actual implementation of the described embodiments and variations is within the capabilities of those skilled in the art.

Claims

1. A device for controlling the pre-charging of a large-capacity capacitor and for detecting faults in a DC current circuit, characterized in that, The DC current circuit includes the large-capacity capacitor, at least one DC voltage source, and at least a first pre-charge switch coupled to the electrodes of the large-capacity capacitor. The device includes: A pulse transformer, the pulse transformer having a primary coil and at least a first-stage coil and a second-stage coil; and A circuit for controlling the pre-charging of the large-capacity capacitor, the circuit being coupled to the primary coil of the pulse transformer; The primary winding of the pulse transformer includes a first terminal configured to be coupled to the control input terminal of the first pre-charge switch; and The secondary coil of the pulse transformer is configured to be coupled in parallel with the large-capacity capacitor.

2. The device according to claim 1, characterized in that, It also includes at least a first power storage capacitor coupled in parallel with the primary winding of the pulse transformer.

3. The device according to claim 1, characterized in that, Also includes: At least a first voltage rectifier diode, the anode of which is coupled to the first terminal of the first stage coil of the pulse transformer; and / or at least a first current limiting resistor, the electrodes of which are configured to be coupled to the control input of the first precharge switch.

4. The device according to claim 3, characterized in that, It also includes at least a second Zener diode, the cathode of which is coupled to the cathode of the first voltage rectifier diode and the anode of which is configured to be coupled to the control input of the first precharge switch.

5. The device according to claim 1, characterized in that, It also includes at least a second protection diode coupled in series with the second-stage coil of the pulse transformer.

6. The device according to claim 1, characterized in that, The circuit for controlling the pre-charging of the large-capacity capacitor includes at least: A third diode, the cathode of which is coupled to a first terminal of the primary coil of the pulse transformer; A first Zener diode, the anode of which is coupled to the anode of the third diode and the cathode of which is coupled to the second terminal of the primary coil of the pulse transformer; as well as A control switch, which is coupled to the second terminal of the primary coil of the pulse transformer.

7. The device according to claim 1, characterized in that, The second terminal of the primary winding of the pulse transformer is coupled to one or more terminals of the secondary winding of the pulse transformer.

8. The device according to claim 1, characterized in that, The pulse transformer includes at least a third-stage coil, the terminals of which are configured to be coupled to a control input of a voltage measuring device or a second precharge switch.

9. A DC current circuit, characterized in that, include: DC voltage source; A bus, the bus comprising at least two conductive elements, each conductive element coupled to one or more terminals of the DC voltage source; A capacitive element, the capacitive element forming a large-capacity capacitor, each electrode of the large-capacity capacitor being coupled to one of the two conductive elements of the bus; A first pre-charge switch is coupled to the electrode of the large-capacity capacitor; as well as A device for controlling the pre-charging of the large-capacity capacitor and for detecting faults in the DC current circuit includes: A pulse transformer, the pulse transformer having a primary coil and at least a first-stage coil and a second-stage coil; and A circuit for controlling the pre-charging of the large-capacity capacitor, the circuit being coupled to the primary coil of the pulse transformer; The primary winding of the pulse transformer includes a first terminal configured to be coupled to the control input terminal of the first pre-charge switch; and The secondary coil of the pulse transformer is configured to be coupled in parallel with the large-capacity capacitor.

10. The DC current circuit according to claim 9, characterized in that, The DC voltage source includes at least a battery.

11. The DC current circuit according to claim 10, characterized in that, The first precharge switch includes at least a first thyristor, and the control input terminal of the first precharge switch corresponds to the gate of the first thyristor, and further includes: A second current-limiting resistor, which is coupled in series with the first thyristor; and A first disconnect switch and a second disconnect switch, each disconnect switch being coupled between one or more terminals of the DC voltage source and one electrode of the large-capacity capacitor, at least one of the first disconnect switch and the second disconnect switch comprising a relay.

12. The DC current circuit according to claim 11, characterized in that, One of the first disconnect switch and the second disconnect switch is coupled in parallel with the first thyristor and the second current limiting resistor.

13. The DC current circuit according to claim 9, characterized in that, The DC voltage source includes a totem-pole type AC / DC voltage converter, which includes at least two switching transistors and at least two switching thyristors. The gates of the switching transistors and switching thyristors are each coupled to a third current-limiting resistor and an optocoupler that are coupled in series with each other to form a first pre-charge switch and a second pre-charge switch. The pulse transformer of the device includes at least a third-stage coil; Wherein, the first terminal of the primary winding of the pulse transformer of the device is coupled to the input electrode of one of the optocouplers; and The first terminal of the third stage coil of the pulse transformer in the device is coupled to the input electrode of another optocoupler in the optocoupler.

14. The DC current circuit according to claim 9, characterized in that, The DC voltage source includes a Boost PFC type AC / DC voltage converter with a hybrid bridge, which includes at least two switching diodes and at least two switching thyristors or at least four switching thyristors, the gate of each switching thyristor being coupled to a third current-limiting resistor and an optocoupler that are coupled in series with each other to form a first pre-charge switch and a second pre-charge switch. as well as In this device, the first terminal of the primary coil of the pulse transformer is coupled to the input electrode of each optocoupler in the optocoupler.

15. The DC current circuit according to claim 9, characterized in that, The DC voltage source includes a Boost PFC type AC / DC voltage converter with a diode bridge; and The first pre-charge switch includes at least a first thyristor, a third current-limiting resistor, and an optocoupler that are coupled in series with each other.

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