Method and device for charging a high-voltage battery, vehicle comprising the device

Abstract

Method and device (113) for charging a high-voltage battery (100), wherein the device (113) is designed to charge the high-voltage battery (100) selectively with a first voltage (103), in particular 400 volts, and a second voltage (104), in particular 800 volts, wherein the device (113) comprises a half-bridge (114) which is designed to conduct current for charging a first battery bank (101) of the high-voltage battery (100) and a second battery bank (102) of the high-voltage battery (100) with the first voltage (103) alternately into the first battery bank (101) and the second battery bank (102), or to conduct no current for jointly charging the first battery bank (101) and the second battery bank (102) with the second voltage (104), wherein the half-bridge (114) has a connection (117) for a center tap at which the first Battery bank (101) and the second battery bank (102) are permanently connected in series.Vehicle comprising the device (113).

Description

[0001] The invention relates to a device for charging a high-voltage battery and a vehicle comprising the device.

[0002] To achieve high performance during driving and charging, on-board networks with voltages of 800 volts and more are increasingly being used.

[0003] In some markets, the availability of 800-volt charging infrastructure is limited or nonexistent. Therefore, a 400-volt charging option is often necessary, at least with a low power as an emergency charging option.

[0004] DE 10 2017 123 458 A1 discloses a method and a system for autonomously connecting at least two battery banks in a drive system of a motor vehicle in the vehicle's internal power grid, in which the at least two battery banks can be switched to form a high-voltage battery. This system can also switch between two banks in a charge state that are either connected in parallel or in series. The switching can also be implemented such that the two banks function as a high-voltage battery for 800 V operation, as opposed to 400 V operation.

[0005] The published patent application DE 10 2017 216 388 A1 discloses a traction network of a motor vehicle, comprising at least one control unit, a high-voltage battery, at least one intermediate circuit capacitor, a three-phase electric machine, and an inverter with three half-bridges, wherein at least two semiconductor switching elements are arranged in each of the half-bridges, to each of which a diode is connected in anti-parallel, wherein at least one connection is provided for connecting an external DC voltage source, wherein the control unit is designed to control the inverter in such a way that it is operated as a DC / DC converter, including the inductances of the electric machine, wherein switching elements are assigned to at least the inductance of one phase, wherein the control unit is designed to control the switching elements in such a way that the current flow through the inductance is opposite to the current flow through the inductances of the other two phases.

[0006] EP 2 429 070 A2 discloses a DC-DC converter with improved efficiency in a dual-voltage vehicle electrical system.

[0007] The device according to claim 1 enables a charging option with 400 volts that is as light as possible and optionally inexpensive.

[0008] The device for charging a high-voltage battery is designed to charge the high-voltage battery selectively with a first voltage, in particular 400 volts, and a second voltage, in particular 800 volts, wherein the device comprises a half-bridge which is designed to conduct current for charging a first battery bank of the high-voltage battery and a second battery bank of the high-voltage battery with the first voltage alternately into the first battery bank and the second battery bank, or to conduct no current for jointly charging the first battery bank and the second battery bank with the second voltage, wherein the half-bridge has a connection for a center tap to which the first battery bank and the second battery bank are permanently connected in series.

[0009] The device comprises, for example, a common contact for the first voltage and the second voltage.

[0010] The device preferably comprises a diode arranged between the half-bridge and the high-voltage battery, wherein the diode is designed to block a current flow from the high-voltage battery to the half-bridge when charging the high-voltage battery with the first voltage and when charging the high-voltage battery with the second voltage.

[0011] In one example, the device comprises a common switch for the first voltage and the second voltage, wherein the switch is arranged between the contact and the half-bridge, wherein the switch is configured to close or break an electrical connection between the half-bridge and the contact.

[0012] In one example, the device comprises a switch for the first voltage and a switch for the second voltage, wherein the switch for the first voltage is arranged between the contact and the half-bridge and is configured to establish or break an electrical connection between the half-bridge and the contact, and wherein the switch for the second voltage is arranged between the contact and the high-voltage battery and is configured to establish or break an electrical connection between the high-voltage battery and the contact.

[0013] It can be provided that the diode is arranged between the half-bridge and the contact, wherein the diode is designed to enable a current flow from the contact to the high-voltage battery when charging the high-voltage battery with the first voltage, and to block a current flow from the contact to the half-bridge when charging the high-voltage battery with the second voltage.

[0014] The half-bridge comprises, for example, two parallel circuits each comprising a switch with a diode each, wherein the diodes are arranged in the reverse direction between a first terminal and a second terminal of the half-bridge, wherein the half-bridge has a third terminal between the diodes, and wherein the high-voltage battery between the first battery bank and the second battery bank is connected to the third terminal.

[0015] For example, the third terminal and the high-voltage battery are connected via a shunt.

[0016] A vehicle may be provided which includes the device.

[0017] A method for charging a high-voltage battery provides that a first voltage, in particular 400 volts, or a second voltage, in particular 800 volts, is detected for charging, wherein a half-bridge is provided which is designed to conduct current for charging a first battery bank of the high-voltage battery and a second battery bank of the high-voltage battery with the first voltage alternately into the first battery bank and the second battery bank, wherein the half-bridge has a connection for a center tap to which the first battery bank and the second battery bank are permanently connected in series, wherein the half-bridge is designed not to conduct any current for jointly charging the first battery bank and the second battery bank with the second voltage, wherein the half-bridge is controlled, when the first voltage is detected, to conduct current through the connection for the center tap alternately into the first battery bank and the second battery bank,and wherein the half-bridge is controlled when the second voltage is detected not to conduct any current for jointly charging the first battery bank and the second battery bank with the second voltage.

[0018] Further advantageous embodiments can be found in the following description and the drawing. The drawing shows: Fig. 1 is a schematic diagram of a device for charging a high-voltage battery according to a first example. Fig. 2 a schematic representation of a device for charging a high-voltage battery according to a second example.

[0019] In Fig. Figure 1 schematically shows a high-voltage battery 100 with a first battery bank 101 and a second battery bank 102. The first battery bank 101 is configured to provide a first voltage, in this example, 400 volts. The second battery bank 102 is configured to provide the first voltage. The first battery bank 101 and the second battery bank 102 are permanently connected in series at a center tap. For example, the first battery bank 101 and the second battery bank 102 are connected via a copper bar.

[0020] The high-voltage battery 100 is designed to provide a second voltage 104, in the example 800 volts.

[0021] The high-voltage battery 100 can be charged via a first contact 105 and a second contact 106 with either the first voltage 103 or the second voltage 104.

[0022] In Fig. 1 schematically illustrates a charging station 107. The charging station 107 is configured to selectively provide either the first voltage 103 or the second voltage 104 between the first contact 105 and the second contact 106.

[0023] The first battery bank 101 includes a positive pole 108 and a negative pole 109. The second battery bank 102 includes a positive pole 110 and a negative pole 111.

[0024] In Fig. 1, a device 113 for charging the high-voltage battery 100 according to a first example is schematically shown.

[0025] The device 113 comprises a half-bridge 114 with a first terminal 115, a second terminal 116 and a third terminal 117. The half-bridge 114 comprises a first parallel circuit 118 of a first switch 119 and a first diode 120. The half-bridge 114 comprises a second parallel circuit 121 of a second switch 122 and a second diode 123. The first diode 120 and the second diode 123 are arranged in the reverse direction of the first diode 120 and the second diode 123 between the first terminal 115 and the second terminal 116 and connect the first terminal 115 and the second terminal 116. The third terminal 117 is connected between the first diode 120 and the second diode 123 to the first diode 120 and the second diode 123. The third terminal 117 is connected via a shunt 124 to the negative pole 109 of the first battery bank 101 and the positive pole 110 of the second battery bank 102.

[0026] The device 113 comprises a third diode 125 which is arranged in the reverse direction of the third diode 125 between the positive contact 108 of the first battery bank 101 and a first terminal 115 of the half-bridge 114, and connects the positive contact 108 of the first battery bank 101 and the first terminal 115 of the half-bridge 114.

[0027] The device 113 comprises a fourth diode 126 which is arranged in the forward direction of the fourth diode 126 between the negative contact 111 of the second battery bank 102 and a second terminal 116 of the half-bridge 114, and connects the negative contact 111 of the second battery bank 102 and the second terminal 116 of the half-bridge 114.

[0028] In the example, the first contact 105 is connected to the first terminal 115 of the half-bridge 114. The second contact 106 is connected to the second terminal 116 of the half-bridge 114.

[0029] The device 113 is configured to control the half-bridge 114 for charging the high-voltage battery 100 with the first voltage 103, so as to conduct the current either along a first path 1 into the first battery bank 101 or along a second path 2 into the second battery bank 102. For example, the device 113 is configured to conduct the current alternately into the first battery bank 101 and the second battery bank 102.

[0030] For example, the device 113 is configured to monitor a charge level of the first battery bank 101 and the second battery bank 102. For example, the device 113 is configured to alternately conduct the current at time intervals to the first battery bank 101 and the second battery bank 102, thereby maintaining the charge level of the first battery bank 101 equal to or substantially equal to the charge level of the second battery bank 102.

[0031] The device 113 is designed to control the half-bridge 114 for charging the high-voltage battery 100 with the second voltage 104 to conduct the current via a third path 3 into the first battery bank 101 and the second battery bank 102.

[0032] In the example, the device 113 comprises a third switch 127, which is arranged between the first contact 105 and both the first terminal 115 and the third diode 125. The third switch 127 is configured to selectively establish or break the electrical connection between the first contact 105 and both the first terminal 115 and the third diode 125.

[0033] In the example, the device 113 comprises a fourth switch 128 arranged between the second contact 106 and both the second terminal 116 and the fourth diode 126. The fourth switch 128 is configured to selectively establish or break the electrical connection between the second contact 106 and both the second terminal 116 and the fourth diode 126.

[0034] In the example, the third switch 127 and the fourth switch 128 are designed as contactors for the first voltage 103 and the second voltage 104.

[0035] In Fig. 2, a device 113 for charging the high-voltage battery 100 according to a second example is schematically shown.

[0036] The device 113 according to the second example is designed like the device 113 according to the first example.

[0037] The device 113 according to the second example additionally comprises a fifth switch 129, which is arranged in an additional electrical connection between the first contact 105 and the positive pole 108 of the first battery bank 101. The fifth switch 129 is configured to selectively establish or break the electrical connection between the first contact 105 and the positive pole 108 of the first battery bank 101.

[0038] The device 113 according to the second example additionally comprises a sixth switch 130, which is arranged in an additional electrical connection between the second contact 106 and the negative pole 111 of the second battery bank 102. The sixth switch 130 is configured to selectively establish or break the electrical connection between the second contact 106 and the negative pole 111 of the second battery bank 102.

[0039] The third switch 127 and the fourth switch 128 can be designed as contactors for the first voltage 103. The fifth switch 129 and the sixth switch 130 are designed in the example as contactors for the second voltage 104.

[0040] The device 113 is designed to control the switches such that the third switch 127 and the fourth switch 128 are closed and the fifth switch 129 and the sixth switch 130 are open simultaneously or substantially simultaneously.

[0041] The device 113 is designed to control the switches such that the third switch 127 and the fourth switch 128 are opened and the fifth switch 129 and the sixth switch 130 are closed simultaneously or substantially simultaneously.

[0042] The device 113 comprises, for example, an electrical circuit, in particular a microcontroller, which is designed to detect the voltage between the first contact 105 and the second contact 106 and to control the half-bridge 114 and the switches for the described charging according to the detected voltage.

[0043] A method for charging the high-voltage battery 100 provides that the voltage between the first contact 105 and the second contact 106 is detected and the half-bridge 114 and the switches for charging are controlled according to the detected voltage.

[0044] The method provides that when the first voltage 103 is detected, the half-bridge 114 is controlled to conduct current through the terminal 117 for the center tap alternately into the first battery bank 101 and the second battery bank 102.

[0045] The method provides that the half-bridge 114 is controlled when the second voltage 104 is detected so as not to conduct any current for jointly charging the first battery bank 101 and the second battery bank 102 with the second voltage 104.

Claims

[1] Device (113) for charging a high-voltage battery (100), characterized by that the device (113) is designed to charge the high-voltage battery (100) selectively with a first voltage (103), in particular 400 volts, and a second voltage (104), in particular 800 volts, wherein the device (113) comprises a half-bridge (114) which is designed to conduct current for charging a first battery bank (101) of the high-voltage battery (100) and a second battery bank (102) of the high-voltage battery (100) with the first voltage (103) alternately into the first battery bank (101) and the second battery bank (102), or to conduct no current for jointly charging the first battery bank (101) and the second battery bank (102) with the second voltage (104), wherein the half-bridge (114) has a connection (117) for a center tap to which the first battery bank (101) and the second battery bank (102) are permanently connected in series. [2] Device (113) according to claim 1, characterized by that the device (113) comprises a common contact (105) for the first voltage (103) and the second voltage (104) [3] Device (113) according to claim 1 or 2, characterized by in that the device (113) comprises a diode (125) which is arranged between the half-bridge (14) and the high-voltage battery (100), wherein the diode (125) is designed to block a current flow from the high-voltage battery (100) to the half-bridge (114) when the high-voltage battery (100) is charged with the first voltage (103) and when the high-voltage battery is charged with the second voltage (104). [4] Device (113) according to one of claims 1 to 3, characterized bythat the device (113) comprises a common switch (127) for the first voltage (103) and the second voltage (104), wherein the switch (127) is arranged between the contact (105) and the half-bridge (114), wherein the switch (127) is designed to close or break an electrical connection between the half-bridge (114) and the contact (105). [5] Device (113) according to one of claims 1 to 3, characterized bythat the device (113) comprises a switch (127) for the first voltage (103) and a switch (129) for the second voltage (104), wherein the switch (127) for the first voltage (103) is arranged between the contact (105) and the half-bridge (114) and is designed to establish or break an electrical connection between the half-bridge (114) and the contact (105), and wherein the switch (129) for the second voltage (104) is arranged between the contact (105) and the high-voltage battery (100) and is designed to establish or break an electrical connection between the high-voltage battery (100) and the contact (105). [6] Device (113) according to claim 5, characterized bythat the diode (125) is arranged between the half-bridge (114) and the contact (105), wherein the diode (125) is designed to enable a current flow from the contact (105) to the high-voltage battery (100) when the high-voltage battery (100) is charged with the first voltage (103), and to block a current flow from the contact (105) to the half-bridge (114) when the high-voltage battery (100) is charged with the second voltage (104). [7] Device (113) according to one of the preceding claims, characterized byin that the half-bridge comprises two parallel circuits (118, 121) each having a switch (119, 122) each having a diode (120, 123), wherein the diodes (120, 123) are arranged in the reverse direction between a first terminal (115) and a second terminal (116) of the half-bridge (114), wherein the half-bridge (114) has a third terminal (117) between the diodes (120, 123), and wherein the high-voltage battery (100) between the first battery bank (101) and the second battery bank (102) is connected to the third terminal (117). [8] Device (113) according to claim 7, characterized by that the third terminal (117) and the high-voltage battery (100) are connected via a shunt (124). [9] Vehicle, characterized by that the vehicle comprises the device according to one of claims 1 to 8. [10] Method for charging a high-voltage battery (100), characterized bythat a first voltage (103), in particular 400 volts, or a second voltage (104), in particular 800 volts, is detected for charging, wherein a half-bridge (114) is provided which is designed to conduct current for charging a first battery bank (101) of the high-voltage battery (100) and a second battery bank (102) of the high-voltage battery (100) with the first voltage (103) alternately into the first battery bank (101) and the second battery bank (102), wherein the half-bridge (114) has a connection (117) for a center tap to which the first battery bank (101) and the second battery bank (102) are permanently connected in series, wherein the half-bridge (114) is designed not to conduct any current for jointly charging the first battery bank (101) and the second battery bank (102) with the second voltage (104), wherein the half-bridge (114) is activated when the first voltage (103) is detected,to conduct current through the terminal (117) for the center tap alternately into the first battery bank (101) and the second battery bank (102), and wherein the half-bridge (114) is controlled, when the second voltage (104) is detected, not to conduct any current for jointly charging the first battery bank (101) and the second battery bank (102) with the second voltage (104).

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