High-voltage electrical systems and disconnect devices

Abstract

Electrical system (100), comprising: a contactor (220, 222) with two switching contacts (224, 226) and a coil (228) configured to electrically open and close the contacts (224, 226); a high-voltage (“HV”) circuit (104) with a power supply (106) which is electrically connected to at least one of the contacts (224, 226) of the contactor (220, 222); a low-voltage (“LV”) circuit (210) which is electrically connected to the coil (228) and configured to selectively energize the coil (228) of the contactor (220, 222); a disconnecting device (231) which is coupled to the electrical LV circuit (210) and is functional to open the electrical LV circuit (210) in order to actuate an electrical opening of the contacts (224, 226) of the contactor (220, 222); wherein the disconnecting device (231) is further defined as a socket (232) and a plug (234) removable from the socket (232) with a conductive path to complete the electrical LV circuit (210) when the plug (234) is inserted into the socket (232); wherein the socket (232) includes at least one HV access point (306) which is electrically connected to the power supply (106) so that an electrical measurement can be taken at the HV power supply (106) when the plug (234) is not inserted into the socket (232); and an analog-to-digital converter (700) connected to a controller (230) configured to determine a voltage applied to the LV circuit (210), where, if the controller (230) determines that the LV circuit (210) has an undervoltage, the controller (230) prevents the contactors (220, 222) from closing.

Description

TECHNICAL AREA

[0001] The disclosure relates generally to high-voltage electrical systems (“HV”) and in particular to the opening of electrical HV circuits in electrical HV systems of vehicles. BACKGROUND

[0002] Electric and hybrid electric vehicles use a high-voltage electrical system to power one or more electric motors and thus the vehicle. Such systems typically include a power supply, such as a battery, and a load, such as the electric motor. This power supply and load are connected to each other as part of a high-voltage ("HV") electrical circuit.

[0003] Normally, one or more contactors are used to "close" or "open" the high-voltage (HV) electrical circuit. This means that the contactor(s) are used to connect and disconnect the power supply to the load. However, it is sometimes necessary to open the HV electrical circuit manually. Service technicians may need to open the HV electrical circuit before performing maintenance or servicing on the vehicle.

[0004] Document US 2016 / 0042900A1 discloses a circuit breaker device comprising two contactors, each having two switching contacts and a coil configured to electrically open and close the switching contacts. The coil is electrically connected to a low-voltage circuit to selectively energize the coil. A high-voltage circuit with a power supply is electrically connected to the switching contacts of the contactors, and these contacts can be opened by means of a breaker coupled to the low-voltage circuit when the breaker interrupts the low-voltage circuit.

[0005] In publication EP 2 495 134 A1, a power supply circuit is disclosed which includes three relays whose coils are supplied with current by a control unit in order to switch the relays on or off and thereby selectively supply an inverter and electric motor with current.

[0006] The publication DE 10 2012 015 523 A1 discloses a high-voltage battery with discharge capability after a crash, which includes a service disconnect isolating device with an operating element that, when actuated, interrupts an electrical connection to a contactor and thus opens the contactor.

[0007] US patent 5,336,934 A discloses a connection and interlocking circuit for an electric vehicle drive system, arranged between a battery and a drive motor. The connection circuit includes two connectors and an interlocking circuit that interrupts the connection if one of the connectors is in a partially connected position.

[0008] Patent US 9,064,661 B2 discloses systems and methods for determining the operating time of a relay comprising a coil, an armature, and two switching contacts, wherein a current through the coil is measured by a current sensing device comprising a current-sensing resistor.

[0009] In US patent application 2011 / 0075315A1, an energy-saving device is disclosed that connects the coils of switching relays in series and parallel with a voltage source to facilitate the closing of the switching relays. The coils are switched on and off by transistors.

[0010] Document US 2006 / 0071557A1 discloses a power source device for motor vehicles in which the coils of two contactors are connected in series or parallel depending on the voltage level of a battery in order to close the contactors.

[0011] In publication JP 2014 - 216 142 A, a test device for the operation of contactors is disclosed to check the operating state of a contactor by comparing a change in the coil current over time during normal operation with a currently measured value. SUMMARY

[0012] According to an exemplary embodiment, an on-board electrical system includes a contactor with two switching contacts and a coil configured to electrically open and close the contacts. The system also includes a high-voltage (“HV”) circuit with a power supply electrically connected to at least one of the contactor's contacts. Furthermore, the system includes a low-voltage (“LV”) circuit electrically connected to the coil and configured to selectively energize the contactor's coil. A disconnecting device is coupled to the electrical LV circuit and is functional to open the electrical LV circuit, thereby electrically opening the contactor's contacts.The isolating device is defined as a socket and a plug removable from the socket with a conductive path to complete the electrical LV circuit when the plug is inserted. The socket includes at least one HV access point electrically connected to the power supply, allowing electrical measurement at the HV power supply when the plug is not inserted. Additionally, an analog-to-digital converter is provided, which communicates with a controller configured to determine the voltage present at the LV circuit. If the controller determines that the LV circuit is undervoltage, it prevents the contactors from closing. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 is a block diagram of an on-board electrical system which, according to an exemplary embodiment, is implemented in a vehicle; Fig. 2 is an electrical circuit diagram of the vehicle electrical system with a low-voltage ("LV") circuit which can be opened with a disconnecting device, according to an exemplary embodiment; Fig. Figure 3 is an electrical circuit diagram of the vehicle electrical system with an electrical LV circuit and a high-voltage ("HV") circuit, which can be opened with a disconnecting device with a plug inserted into a socket, according to an exemplary embodiment; Fig. 4 is an electrical circuit diagram of the vehicle's electrical system. Fig. 3 with the plug of the disconnecting device removed from the socket, according to an exemplary embodiment; Fig. Figure 5 is an electrical circuit diagram of the vehicle electrical system with the electrical LV circuit with a pair of scanning resistors, according to an exemplary embodiment; Fig. Figure 6 is an electrical circuit diagram of the vehicle electrical system with the disconnecting device arranged within an HV power supply, according to an exemplary embodiment; Fig. Figure 7 is an electrical circuit diagram of the vehicle electrical system with the electrical LV circuit, which is electrically coupled to an analog-to-digital converter (“ADC”) according to an exemplary embodiment; and Fig. Figure 8 is an electrical circuit diagram of the vehicle electrical system with the electrical LV circuit and LV access points. DETAILED DESCRIPTION

[0013] Experts in the field will recognize that terms such as "above," "below," "up," "down," "above," "below," etc., are used descriptively for the figures and do not constitute limitations on the scope of the disclosure defined by the accompanying claims. Furthermore, the teachings herein may be described in relation to the functional or logical block components or various processing steps. It should be noted that such block components may be composed of any number of hardware, software, and / or firmware components configured to perform the specified functions.

[0014] With reference to the figures, in which in many views the same numbers describe the same parts, a 100-meter on-board network is described and illustrated herein.

[0015] In the exemplary embodiment of the Fig. The depicted on-board network 100 is implemented in a vehicle 102, such as an automobile (not separately numbered). However, it should be noted that the on-board network 100 can also be implemented in other vehicles 102, including motorcycles, aircraft, locomotives, and boats. Furthermore, the on-board network 100 depicted and described herein can also be implemented in non-vehicle applications (not shown).

[0016] The electrical system 100 includes a high-voltage (“HV”) circuit 104. In the exemplary embodiment, the electrical HV circuit 104 is configured to support voltages greater than 60 volts (“V”). However, it should be noted that the electrical HV circuit can be configured to support any voltage.

[0017] An HV power supply 106 is electrically connected to the electrical HV circuit 104 for powering the electrical HV circuit 104. The electrical HV circuit 104 is also electrically connected to a load 108. In the exemplary embodiment, the load 108 includes a traction inverter module (“TPIM”) (not shown separately), which is sometimes simply referred to as a “traction inverter”. The load 108 of the exemplary embodiment also includes an electric motor (not shown separately) which is electrically connected to the TPIM. As is known to those skilled in the art, the electric motor can be coupled to an axle (not numbered) and / or wheels 112 for driving the vehicle 102.

[0018] In the exemplary embodiment, shown in Fig. 2. The HV power supply 106 includes a battery 200 with multiple cells (not separately numbered). The HV power supply 106 can also be implemented with other devices, including a solar cell (not shown). Furthermore, multiple HV power supplies 106 can be electrically connected to the electrical HV circuit 104.

[0019] The on-board network 100 includes, with further reference to Fig. 2, furthermore a low-voltage (“LV”) electrical circuit 210. In the exemplary embodiment, the electrical LV circuit 210 is configured to support voltages of about 12 volts (V). However, it should be noted that the electrical LV circuit can be configured to support any voltage. The electrical LV circuit 210 includes an LV power supply 212. In the exemplary embodiment, the LV power supply 212 includes a battery 214 with multiple cells (not separately numbered). Of course, as is known to those skilled in the art, the LV power supply 212 can be implemented with other devices. Furthermore, the electrical LV circuit 210 can include multiple LV power supplies 212.

[0020] The electrical system 100 further includes at least one contactor 220, 222 for opening (i.e., preventing current flow) and / or closing (i.e., allowing current flow) the electrical HV circuit 104. Each contactor 220, 222 includes a first contact 224, a second contact 226, and a coil 228. As is known to those skilled in the art, the coil 228, i.e., an electromagnet, causes the contacts 224, 226 to connect or disconnect in order to close or open the circuit.

[0021] In the exemplary embodiment shown in Fig. As shown in Figure 2, System 100 includes a positive contactor 220, which is electrically connected to a positive terminal (unnumbered) of the HV power supply 106, and a negative contactor 222, which is electrically connected to a negative terminal (unnumbered) of the HV power supply 106. Specifically, the first contact 224 of each contactor 220, 222 is electrically connected to the HV power supply 106, and the second contact 226 of each contactor 220, 222 is electrically connected to the load 108. It should be noted that System 100 can implement either a single contactor or additional contactors (e.g., a pre-charge contactor).

[0022] The electrical LV circuit 210 of the exemplary embodiment also includes at least one transistor 229 in conjunction with at least one of the contactors 220, 222 for operating the respective contactors 220, 222. In the exemplary embodiment, which is shown in Fig. As shown in Figure 2, a first transistor 229 is electrically connected to the coil 228 of the first contactor 220. The first transistor 229 can be activated and / or deactivated by a controller 230 to selectively operate the positive contactor 220. Other switching devices (not shown) can, of course, be used instead of and / or in addition to the at least one transistor 229. Furthermore, additional transistors and / or other switching devices can be used while operating the various contactors 220, 222.

[0023] The vehicle electrical system 100 includes a disconnect device 231. The disconnect device 231 can alternatively be referred to as a "manual service disconnect" and / or abbreviated as "MSD". In the exemplary embodiments, the disconnect device 231 is implemented with a socket 232 and a plug 234 that can be removed from the socket 232. In the exemplary embodiments, the plug 234 is partially formed from a non-conductive material, e.g., plastic or ceramic. The plug 234 includes a first conductive trace 236 to complete the electrical LV circuit 210 when the plug 234 is inserted into the socket 232. The first conductive trace 236 is formed mainly from a conductive material, for example, a metal, which is encased by the non-conductive material. As such, a user can safely grasp the plug 234 by hand to remove it from the socket 232.However, it should be noted that in other embodiments the separating device 231 can be implemented with other devices, e.g. a push button (not shown).

[0024] The disconnecting device 231 is coupled to the electrical LV circuit 210 and is functional to open the electrical LV circuit 210 in order to electrically open the contacts 224, 226 of at least one of the contactors 220, 222. In the exemplary embodiment shown in Fig. As shown in Figure 2, the coil 228 of the positive contactor 220 is switched off when the electrical LV circuit 210 is opened, e.g., by removing the plug 234 from the socket 232, which opens the contacts 224, 226 of the positive contactor 220. Thus, the electrical HV circuit 104 is opened and current ceases to flow between the HV power supply 106 and the load 108.

[0025] In some exemplary embodiments, for example in the embodiment according to Fig. 3, the disconnecting device 231 is coupled to the electrical HV circuit 104 and configured to electrically open the electrical HV circuit 104. In particular, the disconnecting device 231 is configured to electrically disconnect the HV power supply 106 from the load 108. In particular, the disconnecting device 231 of the exemplary embodiment of Fig. 3. The disconnecting device 231 can be operated to electrically disconnect the positive terminal of the HV power supply 106 from one of the contacts 224, 226 of the positive contactor 220 and the negative terminal of the HV power supply 106 from one of the contacts 224, 226 of the negative contactor 222. As such, in these embodiments, the disconnecting device 231 provides an additional device for opening the electrical HV circuit 104 and for disconnecting the HV power supply 106 from the load 108.

[0026] In the exemplary embodiment shown in Fig. As shown in Figure 3, the electrical HV circuit 104 is connected via the plug 234 to both the positive terminal of the HV power supply 106 and the negative terminal of the HV power supply 106.

[0027] In particular, the plug 234 includes a second conductor track 300, which electrically connects the positive terminal of the HV power supply 106 and the first contact 224 of the positive contactor 220 when the plug 234 is inserted into the socket 232. The plug 234 also includes a third conductor track 302, which electrically connects the negative terminal of the HV power supply 106 and the first contact 224 of the negative contactor 222. However, it should be noted that other techniques for electrically opening the electrical HV circuit 104 with the disconnecting device 231 can be implemented.

[0028] In an exemplary embodiment, the disconnecting device 231 is configured to open the electrical LV circuit 210 before the electrical HV circuit 104 opens. As described above, the contacts 224, 226 of at least one of the contactors 220, 222 are opened when the electrical LV circuit 210 is open. Thus, the load 108 can be disconnected from the HV power supply 106 before the electrical HV circuit 104 is opened by the disconnecting device 231.

[0029] This arrangement can eliminate or significantly reduce the chance of sparking within the disconnecting device 231. Reduced sparking increases the service life of the disconnecting device 231. For example, the mechanical disconnecting contacts (unnumbered) of the disconnecting device 231 will not receive a high current. Therefore, these contacts do not need to be designed to withstand high temperatures combined with high current. This prevents the plug 234 from being damaged or compromised, which could potentially cause further damage when it is plugged back into the socket 232. This arrangement also eliminates the need for the disconnecting device 231 to include one or more resistors that are normally used to detect when the plug 234 is removed from the socket 232.

[0030] The disconnecting device 231 can also include a fuse 304, which is arranged in series with the electrical HV circuit 104, as shown in Fig. Figure 3 shows that, as experts in the field know, fuse 304 opens circuit 104 when current exceeds a predetermined level.

[0031] The on-board network 100 includes at least one HV access point 306, which is electrically connected to the HV power supply 106. This at least one HV access point 306 enables electrical measurements, such as voltage measurements, of the HV power supply 106. Fig. 4 represents, for example, the on-board network 100 of Fig. Figure 3 shows the plug 234 unplugged from socket 232. With plug 234 removed from the socket, a pair of HV access points 306 are exposed to enable electrical measurements. The system 100 may also include, for example, a special measuring device and / or an adapter (not shown) that is plugged into socket 232 to provide easy access to the HV access points 306. Furthermore, access to the electrical energy of the HV power supply 106 can be provided via access to the HV access points 306.

[0032] In the exemplary embodiment, which the Fig. As shown in Figure 5, the electrical LV circuit 210 supplies current to the coils 228 of both the positive contactors 220 and the negative contactors 222. The isolating device 231 can be used to remove current from both coils 228 when the electrical LV circuit 210 opens, thus opening the contacts 224 and 226 of the two positive and negative contactors 220 and 222.

[0033] The disconnecting device 231 can be arranged at various physical locations and / or at various electrical locations within the vehicle electrical system 100. In the exemplary embodiment shown in Fig. As shown in Figure 6, the disconnecting device 231 can, for example, be arranged within the HV power supply 106. In this exemplary embodiment, in particular, the disconnecting device 231 is arranged in series between two of the cells of the battery 200.

[0034] With reference to Fig. 2-6 The electrical LV circuit 210 can include at least one scanning resistor 240, 500. In the exemplary embodiments shown in the Fig. As shown in Figures 2-6, a first sampling resistor 240 is arranged in series between the positive terminal of the LV power supply 212 and the coil 228 of the positive contactor 220. A first current sensor 242 is arranged next to the sampling resistor 240 to detect the current flowing through the sampling resistor 240. The controller 230 is connected to the first current sensor 242 to receive data corresponding to the current flowing through the sampling resistor 240. In the exemplary embodiment shown in Fig. As shown in Figure 5, a second scanning resistor 500 is arranged in series between the positive terminal of the LV power supply 212 and the coil 228 of the negative contactor 222. Likewise, a second current sensor 502 is implemented similarly to the first current sensor 242 described above. The scanning resistors 240 and 500 and the current sensors 242 and 502 can be used to detect the opening or closing of the disconnecting device 231 as the current decreases from the perspective of the control unit 230.

[0035] The scanning resistors 240, 500, and thus the coils 228, can also be used to indicate whether the contacts 224, 226 of the contactors 220, 222 are welded together or otherwise stuck. In particular, the inductance of the coils 228 changes depending on the position of the contactors 220, 222. As such, an electrical "signature" can be detected when the contactors 220, 222 are welded versus when they are not. This signature can be detected in the initial moments when the coil 228 is energized. Therefore, the controller 230 can use the data provided by the current sensor 242, 502 to determine whether the contacts 224, 226 of the contactors 220, 222 are welded together or otherwise stuck.

[0036] With reference to Fig. 7. The on-board network 100 includes an analog-to-digital converter (“ADC”) 700, which is electrically connected to the electrical low-voltage circuit 210 for sensing the voltage of the electrical low-voltage circuit 210. In the exemplary embodiment, the ADC 700 is electrically connected to the high-side of the coil 228 of the positive contactor 220. However, it should be noted that the ADC 700 can be electrically connected at other points in the electrical low-voltage circuit 210 and / or the coil 228 of the negative contactor 222.

[0037] The ADC 700 is connected to the controller 230, allowing the controller 230 to receive data and / or other signals from the ADC 700. Through communication with the ADC 700, the controller 230 is configured to determine the voltage applied to the electrical LV circuit 210. The controller 230 can then determine that the voltage of the electrical LV circuit 210 is insufficient to properly drive the contactors 220 and 222. The controller 230 then prevents the contactors 220 and 222 from closing, thus preventing damage to them. In particular, the on-board power supply 100 of the embodiment described in Fig. Figure 7 does not show that a high-voltage interlock (“HVIL”) loop is passed through the disconnecting device 231.

[0038] With reference to Fig.The HV power supply 106 and the contactors 220 can be enclosed in a housing 800, which prevents access by users and / or technicians for safety reasons. As such, other critical modules 802 can be located outside the housing 800 and electrically connected to the electrical LV circuit 210. By connecting these modules 802 to the electrical LV circuit 210, the module 802 can derive the status and / or problems of the electrical HV circuit 104.

[0039] The detailed description and the drawings or figures support and describe the disclosure, while the scope of the disclosure is defined solely by the patent claims. While some of the best modes and other embodiments for implementing the claimed teachings are described in detail, various alternative designs and embodiments for implementing the disclosure exist, which are defined in the appended claims.

Claims

[1] Electrical system (100), comprising: a contactor (220, 222) with two switching contacts (224, 226) and a coil (228) configured to electrically open and close the contacts (224, 226); a high-voltage (“HV”) circuit (104) with a power supply (106) which is electrically connected to at least one of the contacts (224, 226) of the contactor (220, 222); a low-voltage (“LV”) circuit (210) which is electrically connected to the coil (228) and configured to selectively energize the coil (228) of the contactor (220, 222); a disconnecting device (231) which is coupled to the electrical LV circuit (210) and is functional to open the electrical LV circuit (210) in order to actuate an electrical opening of the contacts (224, 226) of the contactor (220, 222); wherein the disconnecting device (231) is further defined as a socket (232) and a plug (234) removable from the socket (232) with a conductive path to complete the electrical LV circuit (210) when the plug (234) is inserted into the socket (232); wherein the socket (232) includes at least one HV access point (306) which is electrically connected to the power supply (106) so that an electrical measurement can be taken at the HV power supply (106) when the plug (234) is not inserted into the socket (232); and an analog-to-digital converter (700) connected to a controller (230) configured to determine a voltage applied to the LV circuit (210), where, if the controller (230) determines that the LV circuit (210) has an undervoltage, the controller (230) prevents the contactors (220, 222) from closing. [2] Electrical system (100) according to claim 1, wherein the disconnecting device (231) is coupled to the electrical HV circuit (104) for electrically opening the electrical HV circuit (104). [3] Electrical system (100) according to claim 2, wherein the electrical LV circuit (210) is opened before the electrical HV circuit (104) is opened. [4] Electrical system (100) according to claim 2, wherein the power supply (106) includes a positive terminal and a negative terminal; wherein the contactor (220, 222) comprises a positive contactor (220) with two switching contacts (224, 226) and a coil (228) configured to electrically close and open the contacts (224, 226), and a negative contactor (222) with two switching contacts (224, 226) and a coil (228) configured to electrically open and close the contacts (224, 226); wherein the disconnecting device (231) electrically connects the positive terminal of the power supply (106) and one of the contacts (224, 226) of the positive contactor (220) and is functional to electrically disconnect the positive terminal of the power supply (106) from one of the contacts (224, 226) of the positive contactor (220); and wherein the disconnecting device (231) electrically connects the negative terminal of the power supply (106) and one of the contacts (224, 226) of the negative contactor (222) and is functional to electrically disconnect the negative terminal of the HV power supply (106) from one of the contacts (224, 226) of the negative contactor (222). [5] Electrical system (100) according to claim 1, further comprising a scanning resistor (240, 500) arranged in series with the electrical LV circuit (210) to detect the current flowing through the coil (228) of the contactor (220, 222) for determining a fault in the contactor (220, 222). [6] Electrical system (100) according to claim 1, wherein the electrical LV circuit (210) comprises at least one transistor (229) which is electrically connected to the coil (228) for selectively energizing the coil (228). [7] Electrical system (100) according to claim 1, wherein the power supply (106) includes a positive terminal and a negative terminal; wherein the contactor (220, 222) comprises a positive contactor (220) electrically connected to a positive terminal and having two switching contacts (224, 226) and a coil (228) configured to electrically close and open the contacts (224, 226), and a negative contactor (222) electrically connected to a negative terminal and having two switching contacts (224, 226) and a coil (228) configured to electrically open and close the contacts (224, 226); wherein the disconnecting device (231) is coupled to the electrical LV circuit (210) and is functional to open the electrical LV circuit (210) in order to actuate an electrical opening of the positive (220) and negative (222) contactor. [8] Vehicle (102), comprising: a contactor (220, 222) with two switching contacts (224, 226) and a coil (228) configured to electrically open and close the contacts (224, 226); a high-voltage (“HV”) circuit (104) with a power supply (106) which is electrically connected to at least one of the contacts (224, 226) of the contactor (220, 222); a load (108) which is electrically connected to the electrical HV circuit (104) for receiving electrical energy through the power supply (106) and for driving at least one wheel (112); a low-voltage (“LV”) circuit (210) which is electrically connected to the coil (228) and configured to selectively energize the coil (228) of the contactor (220, 222); a disconnecting device (231) which is coupled to the electrical LV circuit (210) and is functional to open the electrical LV circuit (210) in order to actuate an electrical opening of the contacts (224, 226) of the contactor (220, 222); wherein the disconnecting device (231) is further defined as a socket (232) and a plug (234) removable from the socket (232) with a conductive path to complete the electrical LV circuit (210) when the plug (234) is inserted into the socket (232); wherein the socket (232) includes at least one HV access point (306) which is electrically connected to the power supply (106) so that an electrical measurement can be taken at the HV power supply (106) when the plug (234) is not inserted into the socket (232); and an analog-to-digital converter (700) connected to a controller (230) configured to determine a voltage applied to the LV circuit (210), where, if the controller (230) determines that the LV circuit (210) has an undervoltage, the controller (230) prevents the contactors (220, 222) from closing.

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