Bidirectional protection circuit, electrical protection circuit for vehicle and method of protecting electrical system
Patent Information
- Application Number
- TW111127218
- Authority / Receiving Office
- TW · TW
- Patent Type
- Patents
- Current Assignee / Owner
- Priority Date
- 2021-07-22
- Filing Date
- 2022-07-20
- Publication Date
- 2026-07-11
- Estimated Expiration
- 2042-07-19
Smart Images
Figure IMG-2_DRAW_111127218-A0304-14-0001-1 
Figure IMG-2_DRAW_111127218-A0304-14-0002-2 
Figure IMG-2_DRAW_111127218-A0304-14-0003-3
Abstract
Description
Technical Field
[0001] This article discloses circuit systems and technologies for providing overcurrent and voltage protection. [Related Applications]
[0002] This application claims priority over U.S. Provisional Patent Application No. 63 / 224,713, filed on July 22, 2021, entitled “FUSE AND PROTECTION CIRCUIT BASED UPON BIDIRECTIONAL SWITCH”, the entire contents of which are incorporated herein by reference. Prior Technology
[0003] Today, the internal electrical systems of electric vehicles, such as cars or trucks, are powered by batteries with a set voltage ranging from several hundred volts to 1 kilovolt or higher. To limit current in case of a fault, such vehicles are equipped with non-resettable fuses, such as high-temperature fuses or melting fuses that limit the current to a specified maximum value, beyond which the fuse will trip.
[0004] Although this type of fuse can provide sufficient protection for the vehicle's electrical system, it needs to be replaced after a failure event.
[0005] In view of these and other considerations, the improvements of the present invention may be helpful. Summary of the Invention
[0006] In one embodiment, a bidirectional protection circuit may include: a first reverse-blocking insulated-gate bipolar transistor (IGBT) having a first gate terminal, a first collector terminal, and a first emitter terminal; a second reverse-blocking IGBT having a second gate terminal, a second collector terminal electrically coupled to the first emitter terminal, and a second emitter terminal electrically coupled to the first collector terminal, wherein the first IGBT and the second IGBT define a first current path extending from the first collector terminal to the second emitter terminal; and a switching control circuit coupled to send a control signal to at least one of the first gate terminal and the second gate terminal during an overcurrent event.
[0007] In another embodiment, an electrical protection circuit for a vehicle is provided. The electrical protection circuit may include: a bidirectional switch including a first reverse-blocking IGBT and a second reverse-blocking IGBT electrically coupled to the first reverse-blocking IGBT via a pair of emitter-collector connections; a current sensing circuit coupled to measure internal current in the vehicle's internal electrical system; and logic circuitry coupled to receive signals from the current sensing circuitry, and further including at least a gate driver circuit coupled to a first gate of the first reverse-blocking IGBT and a second gate of the second reverse-blocking IGBT.
[0008] In another embodiment, a method may include: conducting forward and reverse currents via a bidirectional switch when the current level of the current passing through the electrical system is below a tripping level; determining the occurrence of an overcurrent condition when the tripping level is reached; and sending a signal to block current transmission through the electrical system when an overcurrent condition occurs. Simple Explanation of the Diagram
[0009] Figure 1 is a representative diagram of an electrical protection circuit for providing bidirectional protection according to an exemplary embodiment.
[0010] Figure 2 shows details of one embodiment of the protection circuit.
[0011] Figure 3 shows the physical layout of one embodiment of a bidirectional switch.
[0012] Figure 4A shows a circuit representation of an embodiment of the bidirectional switch shown in Figure 1, formed by two IGBTs with reverse blocking capability.
[0013] Figure 4B shows a first scenario of operating the embodiment of the bidirectional switch shown in Figure 4A.
[0014] Figure 4C shows a second scenario of operating the embodiment of the bidirectional switch shown in Figure 4A.
[0015] Figure 5 illustrates an exemplary manufacturing process. Implementation
[0016] This document discloses circuit systems and techniques for providing overcurrent and voltage protection. The circuits are characterized by bidirectional switches, wherein, according to some embodiments, these bidirectional switches may be formed from a pair of insulated-gate bipolar transistors (IGBTs).
[0017] Figure 1 is a representative diagram of an electrical protection circuit 100 for providing bidirectional protection according to an exemplary embodiment. The electrical protection circuit 100 may include a bidirectional switch 104 and a protection circuit 110. The protection circuit 110 includes a current sensing circuit 108 coupled to measure internal current in the vehicle's internal electrical system 106, and also includes a logic circuit 112 coupled to receive signals from the current sensing circuit 108. As shown, the logic circuit 112 may include a gate driver circuit system and a microcontroller circuit system. In the configuration shown in Figure 1, the bidirectional switch 104 is located between the battery 102 and the internal electrical system 106.
[0018] As an example, according to various non-limiting embodiments, in an electric vehicle, battery 102 may generate a voltage between 400 volts and 1000 volts. In this way, bidirectional switch 104 may be arranged to establish or interrupt the electrical connection between battery 102 and internal electrical system 106. During normal operation, bidirectional switch 104 may be configured to connect battery 102 to internal electrical system 106 (where, according to some non-limiting embodiments, operating currents of hundreds or even more than one thousand amperes may be allowed to flow). During fault condition 109 (e.g., an overcurrent event caused by a short circuit during operation or maintenance), bidirectional switch 104 may be configured to interrupt the connection between battery 102 and internal electrical system 106. Note that fault condition 109 is shown to occur in multiple locations, as faults can generally occur anywhere within the electrical system.
[0019] As shown in Figure 1, the current sensing circuit 108 can be coupled to measure the total DC current supplied to the vehicle, thus protecting the entire system from central measurement. In fault conditions, the current sensing circuit 108 can detect excessive current exceeding a threshold current accordingly.
[0020] Subsequently, logic circuit 112 can be coupled to current sensing circuit 108 to receive current sensing signals generated by current sensing circuit 108, which indicate faults or overcurrent events. Upon receiving this signal from current sensing circuit 108, logic circuit 112 can be triggered to send a switch-off signal to bidirectional switch 104 to interrupt the connection between battery 102 and internal electrical system 106 and prevent damage to internal electrical system 106.
[0021] Figure 2 illustrates details of one embodiment of the protection circuit 110. In this example, the bidirectional switch 104 is implemented as an IGBT-based bidirectional switch, the details of which will be discussed below with reference to Figures 4A to 4C. In short, the bidirectional switch 104 may include n pairs of IGBTs, each pair comprising a first IGBT and a second IGBT electrically coupled to the first IGBT via a pair of emitter-collector connections. Advantageously, this configuration provides reverse voltage blocking capability in both directions, as well as the ability to conduct current in both directions. Furthermore, this configuration can shut off current regardless of its direction. In some embodiments, each IGBT forming a given IGBT pair of the bidirectional switch 104 may be implemented in a separate silicon die. An additional advantage of the configuration of the bidirectional switch formed by the first IGBT and the second IGBT electrically coupled to the first IGBT via a pair of emitter-collector connections is that losses are minimized when operated, as losses occur within a single semiconductor device or die. Note that the configuration of reverse-blocking IGBTs has been considered to inherently have lower dynamic performance compared to classic IGBT circuits without reverse blocking capability. However, the inventors have recognized that, for example, in the implementation of the protection circuit system shown in Figures 1 and 2, dynamic performance will be irrelevant because bidirectional fault protection will not require superior dynamic performance.
[0022] Figure 3 illustrates one embodiment of the bidirectional switch 104, wherein n pairs of IGBTs are arranged in, for example, individual semiconductor dies (e.g., silicon dies). Each IGBT pair (e.g., IGBT.1A and IGBT.1B) is arranged such that the first and second IGBTs are configured to conduct bidirectional forward current upward along the current path to a current limit value, which may be set to at least 100 amperes, or at least 200 amperes in some non-limiting embodiments. Each additional IGBT pair may be arranged as an additional semiconductor die pair, as shown in Figure 3, wherein each IGBT pair is configured to conduct current upward to a similar or identical current limit. Thus, in some non-limiting examples, a set of two IGBT pairs may form a switch die assembly, wherein each IGBT pair conducts upward to 200 amperes, or a total of 400 amperes; a set of three IGBT pairs may each conduct upward to 200 amperes, or a total of 600 amperes, and so on.
[0023] According to various embodiments of this disclosure, protection circuitry (e.g., protection circuitry 110) may include programmable components for setting, for example, current threshold values. In one example, logic circuitry 112 may include programmable circuitry that may be configured by the manufacturer for a given application or may be user-programmable.
[0024] Turning now to Figure 4A, a circuit representation of one embodiment of the bidirectional switch 104 is shown. As shown, the circuit arrangement is formed by a pair of IGBTs in a reverse-blocking IGBT configuration, wherein the first IGBT and the second IGBT are coupled to each other via a pair of emitter-to-collector connections. Thus, in Figure 4A, each IGBT is shown as inherently forming a miniature diode. Specifically, the first IGBT 402 has a first emitter terminal 406, a first gate terminal 408, and a first collector terminal 410, and the second IGBT 404 has a second emitter terminal 412, a second gate terminal 414, and a second collector terminal 416. As shown, the first collector terminal 410 is electrically connected to the second emitter terminal 412, and the first emitter terminal 406 is electrically connected to the second collector terminal 416.
[0025] Turning to Figure 4B, a first scenario of operation of the embodiment of the bidirectional switch 104 shown in Figure 4A is illustrated, wherein a forward current 420 passes through the bidirectional switch 104. Turning to Figure 4C, a second scenario of operation of the embodiment of the bidirectional switch 104 shown in Figure 4A is illustrated, wherein a reverse current 422 passes through the bidirectional switch 104. In each scenario, losses may occur in only one IGBT of the bidirectional switch.
[0026] According to various embodiments of this disclosure, during a fault condition in which the logic circuit 112 receives a current sensing signal from the current sensing circuit 108, this current sensing signal can be supplied to the gate terminals of the bidirectional switch 104 to disconnect the current conduction through a given IGBT.
[0027] Specifically, during operation, the gates of the two IGBTs are supplied with sufficient voltage to keep each IGBT in the ON state. Although in principle, sending a signal to turn off the current-carrying IGBT is sufficient during a fault, for safety reasons, both IGBTs can be turned off during a fault.
[0028] Note that, according to existing technology, a pair of sub-circuits can be used to provide bidirectional protection circuitry that typically conducts current in both directions, where each sub-circuit is an IGBT-diode combination. The corresponding IGBTs from each sub-circuit are arranged in series with each other in a common emitter configuration, and the anodes of the corresponding diodes are directly electrically coupled to each other. However, in the prior art, four semiconductor chips may be required to implement this circuit. It is worth noting that, relatively speaking, the configuration of the embodiment shown in Figure 4A results in a loss of 60%, while the loss of a pair of combined IGBT-diode circuits in the prior art is 100%.
[0029] Figure 5 illustrates an exemplary process flow 500. At block 502, a bidirectional switch is provided in the electrical system of a vehicle powered by a high-voltage battery. Non-limiting examples of high-voltage batteries include batteries providing a voltage of 400 volts or higher (e.g., 400 volts to 1000 volts). The bidirectional switch may be formed by n pairs of IGBTs, wherein a given IGBT pair is arranged with a first IGBT and a second IGBT electrically coupled to the first IGBT via a pair of emitter-to-collector connections.
[0030] At block 504, forward or reverse current is conducted via a bidirectional switch and the vehicle's electrical system, wherein the maximum current can be limited to a predetermined level, such as 500 amps, 700 amps, or 1000 amps. For example, the bidirectional switch can be programmed to have an unexceeded tripping level current, and in some embodiments, it can be programmed to limit the current slope during the turn-off period.
[0031] At block 506, overcurrent conditions are detected in the vehicle. For example, a current sensing circuit can be provided in the vehicle to measure the fault current between the motor and the vehicle's internal electrical system. The current sensing circuit can be configured to determine the presence of an overcurrent condition when the current exceeds a predetermined limit. The current sensing circuit can be based on any suitable arrangement, including shunt and Hall sensor circuitry.
[0032] At block 508, based on the determined overcurrent condition, a signal is sent to the bidirectional switch to block current transmission. For example, logic circuitry coupled to the current sensing circuitry and the bidirectional switch may be provided, wherein the logic circuitry includes gate driver circuitry coupled to the gates of the bidirectional switch to open or close the gates.
[0033] As used herein, elements or steps described in the singular and preceded by the indefinite article "a (or an)" should be understood to not exclude a plurality of elements or steps unless such exclusion is explicitly stated. Furthermore, references to "one embodiment" of this disclosure should not be construed as excluding the existence of additional embodiments that also include the described features.
[0034] Although certain embodiments are mentioned in this disclosure, many modifications, alterations, and variations may be made to the embodiments without departing from the scope and range of this disclosure as defined in the appended claims. Therefore, this disclosure is intended to be limited to the embodiments described, but has the full scope defined by the language of the following claims and their equivalents.
[0035] 100: Electrical protection circuit
[0036] 102: Battery
[0037] 104: Two-way switch
[0038] 106: Internal Electrical System
[0039] 108: Current sensing circuit
[0040] 109: Fault Status
[0041] 110: Protection Circuit
[0042] 112: Logic Circuits
[0043] 402: First Insulated Gate Bipolar Transistor (IGBT)
[0044] 404: Second Insulated Gate Bipolar Transistor (IGBT)
[0045] 406: First launch extreme sub-unit
[0046] 408: First gate terminal
[0047] 410: First collector terminal
[0048] 412: Second launch extreme sub-sub-
[0049] 414: Second gate terminal
[0050] 416: Second collector terminal
[0051] 420: Forward current
[0052] 422: Reverse current
[0053] 500: Manufacturing Process
[0054] 502, 504, 506, 508: Square
Claims
1. A bidirectional protection circuit for a vehicle, comprising: The first reverse blocking insulated gate bipolar transistor (IGBT) has a first gate terminal, a first collector terminal and a first emitter terminal; The second reverse blocking insulated gate bipolar transistor has a second gate terminal, a second collector terminal electrically coupled to the first emitter terminal, and a second emitter terminal electrically coupled to the first collector terminal, wherein the first reverse blocking insulated gate bipolar transistor and the second reverse blocking insulated gate bipolar transistor define a first current path extending from the first collector terminal to the second emitter terminal; And a switch control circuit, coupled to send a control signal to at least one of the first gate terminal and the second gate terminal during an overcurrent event, wherein the first reverse blocking insulated gate bipolar transistor and the second reverse blocking insulated gate bipolar transistor form a bidirectional switch, wherein the bidirectional switch is arranged in electrical series between a high-voltage battery generating a voltage greater than 100 volts and the vehicle's internal electrical system.
2. The bidirectional protection circuit as claimed in claim 1, wherein the switching control circuit includes a current sensing circuit coupled to measure a fault current between the motor and the vehicle's internal electrical system.
3. The bidirectional protection circuit as claimed in claim 1, wherein the switch control circuit includes logic circuitry, the logic circuitry including at least a gate driver circuitry coupled to the first gate terminal and the second gate terminal.
4. The bidirectional protection circuit as claimed in claim 1, wherein the first reverse blocking insulated gate bipolar transistor and the second reverse blocking insulated gate bipolar transistor are disposed within a first semiconductor die pair, the first semiconductor die pair being arranged to conduct bidirectional positive current upward along the first current path to a current threshold of at least 200 amperes.
5. The bidirectional protection circuit as described in claim 4, further comprising: The second semiconductor die pair includes: a third reverse blocking insulated-gate bipolar transistor having a third gate terminal, a third collector terminal, and a third emitter terminal; and a fourth reverse blocking insulated-gate bipolar transistor having a fourth gate terminal, a fourth collector terminal electrically coupled to the third emitter terminal, and a fourth emitter terminal electrically coupled to the third collector terminal, wherein the third reverse blocking insulated-gate bipolar transistor and the second reverse blocking insulated-gate bipolar transistor define a second current path, the second current path being electrically parallel to the first current path and extending from the third collector terminal to the fourth emitter terminal.
6. The bidirectional protection circuit of claim 5, wherein the second semiconductor die pair is arranged to conduct the bidirectional positive current upward along the second current path to a current threshold of at least 200 amperes, wherein the first semiconductor die pair and the second semiconductor die pair define a switching die assembly and are arranged to conduct the bidirectional positive current upward along the second current path to a current threshold of at least 400 amperes.
7. The bidirectional protection circuit as described in claim 4, further comprising: One or more additional semiconductor die pairs, each of the one or more additional semiconductor die pairs including a pair of insulated-gate bipolar transistors, wherein each of the one or more additional semiconductor die pairs is arranged in electrical parallel with the first semiconductor die pair, and wherein each of the one or more additional semiconductor die pairs is arranged to conduct the bidirectional positive current upward along the first current path to a current threshold of at least 200 amperes.
8. An electrical protection circuit for a vehicle, comprising: A bidirectional switch includes a first reverse-blocking insulated-gate bipolar transistor and a second reverse-blocking insulated-gate bipolar transistor electrically coupled to the first reverse-blocking insulated-gate bipolar transistor via a pair of emitter-to-collector connectors; a current sensing circuit is coupled to measure the internal current in the vehicle's internal electrical system; The system also includes logic circuitry coupled to receive signals from the current sensing circuitry, and further includes at least a gate driver circuitry coupled to the first gate of the first reverse blocking insulated gate bipolar transistor and the second gate of the second reverse blocking insulated gate bipolar transistor.
9. The electrical protection circuit as claimed in claim 8, wherein the bidirectional switch is arranged in electrical series between a high-voltage battery generating a voltage greater than 100 volts and the vehicle's internal electrical system.
10. The electrical protection circuit of claim 8, wherein the current sensing circuit and the logic circuit form a switch control circuit, wherein the logic circuit includes at least a gate driver circuit coupled to the first gate and the second gate.
11. The electrical protection circuit of claim 8, wherein the first reverse blocking insulated gate bipolar transistor and the second reverse blocking insulated gate bipolar transistor are disposed within a first semiconductor die pair, the first semiconductor die pair being arranged to conduct bidirectional positive current upward along a first current path to a current threshold of at least 200 amperes.
12. The electrical protection circuit as described in claim 11 further includes: The second semiconductor die pair includes: a third reverse blocking insulated-gate bipolar transistor having a third gate terminal, a third collector terminal, and a third emitter terminal; and a fourth reverse blocking insulated-gate bipolar transistor having a fourth gate terminal, a fourth collector terminal electrically coupled to the third emitter terminal, and a fourth emitter terminal electrically coupled to the third collector terminal, wherein the third reverse blocking insulated-gate bipolar transistor and the second reverse blocking insulated-gate bipolar transistor define a second current path, the second current path being electrically parallel to the first current path and extending from the third collector terminal to the fourth emitter terminal.
13. The electrical protection circuit of claim 12, wherein the second semiconductor die pair is arranged to conduct the bidirectional positive current upward along the second current path to a current limit of at least 200 amperes, wherein the first semiconductor die pair and the second semiconductor die pair define a switching die assembly and are arranged to conduct the bidirectional positive current upward along the second current path to a current limit of at least 400 amperes.
14. A method for a protective electrical system for a vehicle, comprising: When the current level of the current passing through the electrical system is lower than the tripping level, the forward and reverse currents are conducted by a bidirectional switch. When the tripping threshold is reached, an overcurrent condition is identified; and when the overcurrent condition occurs, a signal is sent to block current transmission through the electrical system, wherein the bidirectional switch includes n pairs of insulated-gate bipolar transistors, wherein a given pair of insulated-gate bipolar transistors in the n pairs of insulated-gate bipolar transistors includes a first insulated-gate bipolar transistor and a second insulated-gate bipolar transistor electrically coupled to the first insulated-gate bipolar transistor via a pair of emitter-collector terminals.
15. The method of claim 14, wherein the electrical system is located in a vehicle powered by a high-voltage battery.
16. The method of claim 14, wherein the bidirectional switch can be programmed as a current slope during the current-off period.
17. The method of claim 14, wherein the overcurrent condition is determined by a current sensing circuit arranged to measure a fault current between the motor and the electrical system.
18. The method of claim 14, wherein the signal is transmitted from a gate driver circuit coupled to a pair of gates of the bidirectional switch.