Charging device for charging an electrical energy store of a vehicle

Abstract

The invention relates to a charging device (250) for charging an electrical energy store (260) of a vehicle (100), wherein the charging device (25) is designed to convert an alternating current provided at an input of the charging device (250) via a first line (221) and via a second line (222) into a direct current for charging the energy store (260). The charging device (250) comprises, at the input, an isolating switching element (251) which is designed to interrupt the first line (221) in an open state. The charging device (250) further comprises a blocking element (253) which is arranged in a bypass path, arranged parallel to the isolating switching element (251), for bypassing the isolating switching element (251). The blocking element (253) is designed to block a direct current provided via the first line (221) and via the second line (222) and to allow an alternating current provided via the first line (221) and via the second line (222) to pass through at least in part.

Description

[0001] Charger for charging a vehicle's electrical energy storage system

[0002] The invention relates to a charger for charging an electrical energy storage device of a (motor) vehicle.

[0003] An electric vehicle (especially a fully electric vehicle or a plug-in hybrid vehicle) includes an electrical (especially an electrochemical) energy storage device that can be connected to a charging station and charged via a charging interface on the vehicle. Various conductive, i.e., cable-based, charging technologies exist for charging the electrical energy storage device. In so-called AC charging, or alternating current charging, the vehicle has a charger that converts alternating current (also known as AC current) into direct current (also known as DC current) to charge the electrical energy storage device. AC (alternating current) is transmitted on the charging cable between the charging station, e.g., a wallbox, and the vehicle. In so-called DC charging, or direct current charging, DC (direct current) is transmitted on the charging cable.The vehicle's charging interface can have contact elements that are used for both DC and AC current. Specifically, the charging interface can have a first contact element that is connected to the positive terminal of the DC current for DC charging and to the first phase of the AC current for AC charging. Furthermore, the charging interface can have a second contact element that is connected to the negative terminal of the DC current for DC charging and to the second phase or the neutral conductor of the AC current for AC charging.

[0004] This document addresses the technical challenge of providing an efficient and reliable AC charger for a vehicle, where the vehicle has a charging interface with contact elements that can be used for both AC and DC charging.

[0005] The problem is solved by the independent claim. Advantageous embodiments are described, inter alia, in the dependent claims. It should be noted that additional features of a claim dependent on an independent claim, without the features of the independent claim itself or only in combination with a subset of the features of the independent claim, can constitute a separate invention independent of the combination of all features of the independent claim, which can be made the subject of an independent claim, a divisional application, or a subsequent application. This applies equally to technical teachings described in the description, which can constitute an invention independent of the features of the independent claims.

[0006] According to one aspect, a charger for charging an electrical, in particular an electrochemical, energy storage device of a (motor) vehicle is described. The energy storage device can have a nominal voltage of 100V or more, in particular 200V or more, or 400V or more. The energy storage device can be configured to store electrical energy for the operation of an electric drive motor of the vehicle.

[0007] The charger is designed to convert alternating current (AC), supplied to the charger's input via a first and second conductor, into direct current (DC) for charging the energy storage device. The AC current can be supplied at, for example, 110V or 230V. The charger can therefore be designed for a DC and / or AC voltage between the first and second conductors of 100V or more, in particular 200V or more.

[0008] The charger includes an isolating switching element at the input, configured to interrupt the first line when open. The isolating switching element may include a relay, in particular a mechanical relay or a solid-state relay. Alternatively or additionally, the charger may include a second isolating switching element at the input, configured to interrupt the second line when open.

[0009] Furthermore, the charger includes a blocking element arranged in a bypass path parallel to the disconnecting switching element to bypass the disconnecting switching element. The blocking element is preferably designed for a DC and / or AC voltage of 100V or more, particularly 200V or more, between the first and second lines.

[0010] The disconnecting switching element can be configured to short-circuit the bypass path when closed. The bypass path can be designed to reduce the inrush current when the disconnecting switching element closes. In particular, the bypass path can be configured for pre-charging one or more components of the charger. For this purpose, the charger can have a limiting resistor (as a dedicated and / or standalone resistor component) arranged on the bypass path. The limiting resistor can be arranged in series with the blocking element.

[0011] The blocking element is designed to (essentially completely) block a direct current supplied via the first line and via the second line, and to allow an alternating current supplied via the first line and via the second line to pass at least partially.

[0012] The blocking element can be configured, for example, to block a current supplied via the first line and via the second line, in particular direct current and / or alternating current, with the first polarity, and to allow a half-wave of an alternating current supplied via the first line and via the second line with a second polarity that is opposite to the first polarity to pass through (while the half-wave of the alternating current with the first polarity is blocked by the blocking element).

[0013] The blocking element can, for example, include a diode (where the reverse direction of the diode corresponds to the first polarity, and the forward direction of the diode corresponds to the second polarity).

[0014] On the other hand, the blocking element can be designed to allow an alternating current supplied via the first line and via the second line to pass through essentially completely (i.e., both half-waves of the alternating current). The blocking element can, for example, include a capacitor.

[0015] A charger with a (passive) blocking element (which may consist exclusively of one or more passive components) can therefore be provided to enable the charger to efficiently and reliably perform both AC and DC charging via the same (first and second) lines. Furthermore, a (road) motor vehicle (in particular a passenger car, truck, bus, or motorcycle) is described that incorporates the charger described in this document.

[0016] The vehicle can include an electrical energy storage device and a charging interface (in particular a charging socket) with a first contact element and a second contact element. Furthermore, the vehicle can include a first conductor electrically connected to the first contact element and a second conductor electrically connected to the second contact element, wherein the input of the charger is electrically connected to both the first and second conductors.

[0017] The vehicle can be configured to use direct current supplied via the first and second lines directly to charge the energy storage device. Furthermore, the vehicle can be configured to convert alternating current supplied via the first and second lines into direct current for charging the energy storage device using the charger.

[0018] The vehicle may include a control unit. The control unit may be configured to keep the charger's disconnect switch in the open position when, and in particular as long as, it detects that a direct current is being supplied via the first and second leads. Furthermore, the control unit may be configured to close the charger's disconnect switch after a predefined pre-charging period and / or when (e.g., as soon as) the voltage across the disconnect switch falls below a predefined voltage threshold, thus short-circuiting the bypass path through the disconnect switch when, and in particular as soon as, it detects that an alternating current is being supplied via the first and second leads.It should be noted that the devices and systems described in this document can be used both alone and in combination with other devices and systems described in this document. Furthermore, any aspect of the devices and systems described in this document can be combined with one another in a variety of ways. In particular, the features of the claims can be combined with one another in a variety of ways. Features listed in parentheses are to be understood as optional features.

[0019] The invention will now be described in more detail using exemplary embodiments.

[0020] Figure 1 shows a block diagram of an example charging system;

[0021] Figure 2a shows an exemplary AC and DC charging device for a vehicle; and Figure 2b shows an exemplary AC charger for a vehicle.

[0022] As stated at the outset, this document deals with the provision of an efficient and reliable AC charger for a vehicle, which can be used in conjunction with a charging interface that has common contact elements (in particular pins) for AC charging and for DC charging. In this context, Fig. 1 shows a block diagram of an exemplary charging system with a charging station 110 (e.g., a wallbox) and a vehicle 100. The vehicle 100 includes an electrical energy storage device (not shown) that can be charged with electrical energy from the charging station 110. The vehicle 100 includes a charging socket 101 (generally referred to as the charging interface) to which a corresponding (charging) plug 111 of a charging cable 112 can be connected. The charging socket 101 and the plug 111 typically form a plug-in system. The charging cable 112 can be permanently connected to the charging station 110 (as shown).On the other hand, the charging cable 112 can be connected to the charging station 110 via a plug connection (e.g., for AC charging). The charging interface 101 of the vehicle 100 typically includes different contact elements for AC charging and for DC charging. In certain countries (e.g., in the USA, according to the NACS (North American Charging Standard)), charging stations 110 may use the same contact elements for both AC and DC charging. Consequently, depending on the charging station 110, either alternating current or direct current can be supplied at a pair of contact elements of the charging interface 101. The vehicle 100 may have a charging device designed for such a situation, as illustrated by way of example in Fig. 2a.

[0023] The charging device shown in Fig. 2a has a first line 221 and a second line 222, wherein the first line 221 is electrically coupled to a first contact element and the second line 222 to a second contact element of the charging interface 101 of the vehicle 100. In a first charging situation, a direct current can be supplied via the lines 221, 222, which can be directed via the switching elements 261 to the electrical energy storage device 260 in order to charge the energy storage device 260.

[0024] In a second charging situation, an alternating current can be provided via the lines 221, 222, whereby the alternating current is converted into a direct current by a charger 250, which is then (if necessary via the switching elements 262) directed to the energy storage device 260 in order to charge the energy storage device 260.

[0025] Fig. 2b shows an exemplary AC charger 250, which has an isolating switching element 251 on the input side. This element is configured (in the open state) to interrupt the first line 221 when a direct current is supplied via lines 221 and 222. Conversely, when it is detected that an alternating current is supplied via lines 221 and 222, the isolating switching element 251 can be closed to connect the subsequent components 271, 272, 273, and 274 of the charger 250 to lines 221 and 222, thus enabling the transformation of the alternating current on lines 221 and 222 into a direct current for charging the energy storage device 260.

[0026] The charger 250 shown in Fig. 2b has the following components,

[0027] • an inlet filter unit 271 ;

[0028] • one Power Factor Correction (PFC) unit 272;

[0029] • an LLC unit 273 with galvanic isolation; and / or

[0030] • a DC filter unit 274.

[0031] The charger 250 can have one or more components, in particular capacitors, that lead to a relatively high inrush current when the disconnecting switching element 251 closes. For this purpose, the charger 250 can have a limiting resistor 252 that bypasses the disconnecting switching element 251 and is configured to limit the inrush current when the disconnecting switching element 251 closes. In particular, the limiting resistor 252 ensures that the one or more components of the charger 250 are at least partially charged via the limiting resistor 252 in a pre-charging phase before the disconnecting switching element 251 closes, so that no excessively high inrush current flows through the disconnecting switching element 251 when the disconnecting switching element 251 closes.

[0032] The limiting resistor 252 is arranged in a bridging path, the bridging path being arranged parallel to the isolating switching element 251.

[0033] The limiting resistor 252, which bridges the disconnecting switching element 251, causes (without using the blocking element described in this document) that if a DC voltage is present on the lines 221, 222, this DC voltage is passed on via the limiting resistor 252 to the one or more downstream components 271, 272, 273, 274 of the charger 250, which can lead to an impairment of the one or more downstream components 271, 272, 273, 274 of the charger 250.

[0034] The charger 250 comprises a blocking element 253, which is arranged in series (on the bypass path) with the limiting resistor 252, and which is configured to selectively block a direct current and / or a direct voltage supplied via lines 221, 222. Conversely, the blocking element 253 is configured to allow an alternating current and / or an alternating voltage supplied via lines 221, 222 to pass, at least partially and, if necessary, completely.

[0035] In the example shown in Fig. 2b, the blocking element 253 comprises a diode configured to block a direct current and / or a direct voltage (with a specific polarity) supplied via lines 221, 222. When an alternating current and / or an alternating voltage is supplied via lines 221, 222, one half-wave of the alternating current or voltage can pass through the diode to charge the one or more components of the charger 250 and thereby reduce the inrush current when the disconnecting switching element 251 closes. This also allows for pre-charging of the one or more components, particularly capacitors, of the charger 250.

[0036] In another example, the blocking element 253 comprises a capacitor configured to selectively block a direct current and / or a direct voltage, while an alternating current and / or an alternating voltage passes (essentially completely) through the capacitor.

[0037] This describes an AC charger 250 that can be efficiently and reliably connected to lines 221, 222, which, depending on the charging situation, can carry a direct current or voltage, or an alternating current or voltage. The charger 250 has a (passive) blocking element 253, which is arranged in parallel to the isolating switching element 251 of the charger 250, and which is designed to protect the downstream components 271, 272, 273, 274 of the charger 250 from a high-voltage direct current.

[0038] The present invention is not limited to the embodiments shown. In particular, it should be noted that the description and the figures are intended only to illustrate the principle of the proposed devices and systems by way of example.

Claims

Claims 1) Charger (250) for charging an energy storage device (260) of a vehicle (100); wherein - the charger (250) is designed to convert an alternating current supplied via a first line (221) and a second line (222) at an input of the charger (250) into a direct current for charging the energy storage device (260); - the charger (250) includes at the input a disconnect switching element (251) which is configured to interrupt the first line (221) in an open state; and - the charger (250) comprises a blocking element (253) which is arranged in a bridging path parallel to the disconnecting switching element (251) for bridging the disconnecting switching element (251); wherein the blocking element (253) is configured, - to block a direct current supplied via the first line (221) and via the second line (222); and - to allow at least part of the alternating current supplied via the first line (221) and via the second line (222) to pass through. 2) Charger (250) according to claim 1, wherein the blocking element (253) is configured, - to block a current supplied via the first line (221) and via the second line (222), in particular direct current and / or alternating current, with a first polarity; and - a half-wave of an alternating current supplied via the first line (221) and via the second line (222) with a second polarity that is opposite to the first polarity, to let it happen. 3) Charger (250) according to one of the preceding claims, wherein the blocking element (253) comprises a diode. 4) Charger (250) according to one of the preceding claims, wherein the blocking element (253) is configured to allow an alternating current supplied via the first line (221) and via the second line (222) to pass through substantially completely. 5) Charger (250) according to one of the preceding claims, wherein the blocking element (253) comprises a capacitor. 6) Charger (250) according to one of the preceding claims, wherein - the charger (250) has a limiting resistor (252) arranged on the bypass path; and - the limiting resistor (252) is arranged in series with the blocking element (253). 7) Charger (250) according to one of the preceding claims, wherein the charger (250), in particular the blocking element (253), is designed for a DC and / or AC voltage between the first line (221) and the second line (222) of 100V or more, in particular of 200V or more. 8) Charger (250) according to one of the preceding claims, wherein the disconnect switching element (251) comprises a relay, in particular a mechanical relay or a semiconductor relay. 9) Vehicle (100), comprising, - an electrical energy storage device (260); - a charging interface (101) with a first contact element and with a second contact element; - a first conductor (221) electrically connected to the first contact element and a second conductor (222) electrically connected to the second contact element; and - a charger (250) according to one of the preceding claims; wherein an input of the charger (250) is electrically connected to the first line (221) and to the second line (221); wherein the vehicle (100) is configured, - to use direct current supplied via the first line (221) and the second line (222) directly to charge the energy storage device (260); and - to convert an alternating current supplied via the first line (221) and the second line (222) into a direct current for charging the energy storage device (260) using the charger (250). 10) Vehicle (100) according to claim 9, wherein the vehicle (100) comprises a control unit which is configured, - to cause the disconnect switching element (251) of the charger (250) to remain in the open state when, and especially as long as, it is detected that a direct current is supplied via the first line (221) and the second line (222); and - to cause the disconnect switching element (251) of the charger (250) to be switched to the closed state after a predefined pre-charging period and / or when a voltage across the disconnect switching element (251) is less than a predefined voltage threshold, so that the bypass path through the disconnect switching element (251) is short-circuited when, in particular as soon as, it is detected that there is a voltage across the first line (221) and the second Line (222) provides alternating current.

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