Soft clamping circuit for a motor control device power supply rail with reverse polarity protection

Abstract

A motor control system includes a motor controller and a switch located between a battery and a conductor. The motor controller closes the switch when the battery is supplying voltage and opens the switch when the battery is not supplying voltage. A clamping circuit is connected to the conductor. A capacitor is also connected to the conductor. An H-bridge controller is configured to selectively control multiple switches to: supply alternating current to a motor in response to a command from the motor controller; detect voltage on the conductor when the battery is not supplying power to the motor controller; then, when the voltage on the conductor is greater than a first predetermined voltage threshold, close at least two of the multiple switches; and then, when the voltage on the conductor is less than a second predetermined voltage threshold, open at least two of the switches.

Description

INTRODUCTION

[0001] The information provided in this section serves the purpose of providing a general overview of the context of the disclosure. Neither the work of the inventors currently named, to the extent described in this section, nor those aspects of the description that could not otherwise qualify as prior art at the time of filing, are expressly or implicitly recognized as prior art against the present disclosure.

[0002] The present disclosure relates to motor control systems and in particular to a soft-clamping circuit for a motor control device supply rail with reverse polarity protection.

[0003] Vehicles can contain a component, such as a lifting flap, that is powered by a motor. During operation, a controller supplies power from the battery to a motor controller, which operates switches that supply alternating current to the motor. SUMMARY

[0004] A motor control system includes a motor controller and a switch located between a battery and a conductor. The motor controller is configured to close the switch when the battery provides voltage to the conductor and to open the switch when the battery does not provide voltage. A terminal circuit is connected to the conductor. A capacitor is also connected to the conductor.An H-bridge controller is configured to selectively control several switches to supply alternating current to a motor in response to an instruction from the motor controller; to detect a voltage on the conductor when the battery is not providing power to the motor controller; then, if the voltage on the conductor is greater than a first predetermined voltage threshold, to close at least two of the several switches; and then, if the voltage on the conductor is less than a second predetermined voltage threshold, to open at least two of the switches.

[0005] According to further characteristics, the second predetermined voltage threshold is lower than the first predetermined voltage threshold and higher than the battery voltage. The clamping circuit contains a resistor and a Zener diode. The Zener diode has a Zener voltage that is lower than the second predetermined voltage threshold and higher than the battery voltage.

[0006] The multiple switches include a first switch containing a first terminal connected to the conductor; a second switch containing a first terminal connected to a second terminal of the first switch and the first terminal of the motor, and a second terminal connected to ground; a third switch containing a first terminal connected to the conductor; and a fourth switch containing a first terminal connected to a second terminal of the third switch and a second terminal of the motor, and a second terminal connected to ground.

[0007] According to further specifications, at least two of the multiple switches include the second and fourth switches. At least two of the multiple switches include the first and third switches. The first predefined voltage threshold is in the range of 29 volts to 31 volts. The second predefined voltage threshold is in the range of 26 volts to 28 volts. The Zener voltage is in the range of 19 to 21 volts, and the battery voltage is in the range of 10 to 17 volts.

[0008] A motor control system includes a motor controller and a switch located between a battery and a conductor. The motor controller is configured to close the switch when the battery provides voltage to the conductor and to open the switch when the battery does not provide voltage. A terminal circuit is connected to the conductor and includes a resistor connected in series with a Zener diode. A capacitor is also connected to the conductor.An H-bridge controller is configured to selectively control several switches to supply alternating current to a motor in response to a command from the motor controller; to detect a voltage across the conductor when the battery is not supplying power to the motor controller; then, when the voltage across the conductor is greater than a first predefined voltage threshold, to close at least two of the switches; and then, when the voltage across the conductor is less than a second predefined voltage threshold, to open at least two of the switches. The second predefined voltage threshold is less than the first predefined voltage threshold and greater than the battery voltage. The Zener diode has a Zener voltage that is less than the second predefined voltage threshold and greater than the battery voltage.

[0009] According to further characteristics, the multiple switches include a first switch containing a first terminal connected to the conductor; a second switch containing a first terminal connected to a second terminal of the first switch and a first terminal of the motor, and a second terminal connected to ground; a third switch containing a first terminal connected to the conductor; and a fourth switch containing a first terminal connected to a second terminal of the third switch and a second terminal of the motor, and a second terminal connected to ground.

[0010] According to further specifications, at least two of the multiple switches include the second and fourth switches. At least two of the multiple switches include the first and third switches. The first predefined voltage threshold is in the range of 29 volts to 31 volts. The second predefined voltage threshold is in the range of 26 volts to 28 volts. The Zener voltage is in the range of 19 to 21 volts, and the battery voltage is in the range of 10 to 17 volts.

[0011] A vehicle comprises a lifting flap, a motor configured to move the lifting flap, and a motor controller. A switch is placed between a battery and a conductor. The motor controller is configured to close the switch when the battery provides voltage to the conductor and to open the switch when the battery does not provide voltage. A terminal circuit is connected to the conductor and includes a resistor connected in series with a Zener diode. A capacitor is also connected to the conductor.An H-bridge controller is configured to selectively control several switches to supply alternating current to the motor in response to a command from the motor controller; to detect a voltage across the conductor when the battery is not supplying power to the motor controller; then, when the voltage across the conductor is greater than a first predetermined voltage threshold, to close at least two of the switches; and then, when the voltage across the conductor is less than a second predetermined voltage threshold, to open at least two of the switches. The second predetermined voltage threshold is less than the first predetermined voltage threshold and greater than the battery voltage. The Zener diode has a Zener voltage that is less than the second predetermined voltage threshold and greater than the battery voltage.

[0012] According to further characteristics, the multiple switches include a first switch containing a first terminal connected to the conductor; a second switch containing a first terminal connected to a second terminal of the first switch and a first terminal of the motor, and a second terminal connected to ground; a third switch containing a first terminal connected to the conductor; and a fourth switch containing a first terminal connected to a second terminal of the third switch and a second terminal of the motor, and a second terminal connected to ground.

[0013] According to further characteristics, at least two of the multiple switches contain the second switch and the fourth switch.

[0014] Further applications of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and the specific examples serve only for illustration and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present revelation is more fully understood from the detailed description and the accompanying drawings; they show: Fig. 1A a functional block diagram and an electrical diagram of a motor control system for a motor that operates a component such as a vehicle tailgate; Fig. 1B a functional block diagram and an electrical diagram of the control system of Fig. 1A, showing a back electromotive force (EMF) and the charging of a bulk capacitor; Fig. 2 a functional block diagram and an electrical diagram of an example of a motor control system incorporating a soft-clamping circuit according to the present disclosure; Fig. 3. A functional block diagram and an electrical diagram of the engine control system of Fig. 2, which exhibit a counter-electromotive force (EMF) that can occur when the motor is manually turned with the battery disconnected; Fig. 4. A functional block diagram and an electrical diagram of the engine control system of Fig. 2, which show an operation of the H-bridge controller and the soft-clamping circuit according to the present disclosure; and Fig. 5 a flowchart of an example of a method for operating the H-bridge controller according to the present disclosure.

[0016] Reference symbols can be used multiple times in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0017] Vehicles may contain a component, such as a liftgate, sliding door, or other component, that is powered by a motor. During operation, power is supplied from a battery to a motor control system to control the states of several switches that supply AC current to the motor. During assembly or maintenance, situations arise where the battery is disconnected and the motor control system is not powered by the battery. Problems can occur when no power is supplied to the motor control system and the component's motor is manually turned, generating a back EMF. This back EMF can cause a voltage greater than 30 V to be stored in a bulk capacitor within the motor control system, potentially damaging other components of the motor control system.

[0018] With reference to Fig. 1A and Fig. 1B includes a motor control system with an H-bridge driver 20 configured to control the operation of a motor M. Specifically, the H-bridge driver 20 controls the states of switches SW1, SW2, SW3, and SW4 to supply an alternating current through the input terminals of the motor M.

[0019] The H-bridge driver 20 is connected to the control terminals of switches SW1, SW2, SW3, and SW4. Switches SW1 and SW2, and SW3 and SW4, are each connected between a conductor 22 (or a power supply rail or V). supThe switches SW1 and SW3 are connected in series. The first terminals of SW1 and SW3 are connected to conductor 22. The second terminals of SW1 and SW3 are connected to the first terminals of SW2 and SW4. The second terminals of SW2 and SW4 are connected to ground. Switches SW1, SW2, SW3, and SW4 contain inverse diodes D1, D2, D3, and D4, which are connected across the first and second terminals of SW1, SW2, SW3, and SW4.

[0020] The input terminals of motor M are connected to nodes between the second terminals of switches SW1 and SW3 and the first terminals of switches SW2 and SW4. During operation of motor M, the H-bridge driver 20 turns on switches SW1 and SW4 while switches SW2 and SW3 are off (and then vice versa) to supply an alternating current to motor M.

[0021] During vehicle assembly and / or maintenance, the vehicle battery may be disconnected (e.g., no power is supplied to controller 28). When controller 28 is not powered, switch SW5 is normally open (to prevent current from flowing from conductor 22 or the supply rail (V)). sup )) is fed back to the system supply input).

[0022] In Fig. 1B then generates a back electromotive force (EMF) when motor M is manually turned while the battery is disconnected (as shown, for example, by the dotted line). The voltage across conductor 22 rises steadily (e.g., to more than 30 V) and the bulk capacitor C Bulk Charging is underway. The stored energy can damage the controller 28 or other components if the motor's back EMF is not limited.

[0023] With reference to Fig. 2 to Fig. 4. An H-bridge controller 120 acts as a driver, as described above, to selectively supply current in opposite directions via the motor M during normal operation by changing the states of switches SW1, SW2, SW3, and SW4. The bulk capacitor C bulk is connected to conductor 22. The H-bridge controller 120 contains a motor brake module 121, which controls the voltage of the supply rail V. sup detected, optionally short-circuits the motor M connections when V sup greater than a first predetermined voltage threshold V TH1 is, and then a short circuit of the motor M connections optionally stops when V sup smaller than a second predetermined voltage threshold V TH2 is as described below.

[0024] A soft-clamp circuit 134 contains a resistor R and a Zener diode D. Zener, which are connected in series between conductor 22 and ground. The power supply 24 is connected to V BATT The controller 28 is connected to the power supply 24, the H-bridge controller 120, and a control terminal of the switch SW5 (which is between V BATT and is connected to conductor 22). Controller 28 is configured to control H-bridge controller 120 and switch SW5.

[0025] The soft-clamping circuit 134 is configured, the bulk capacitor C bulk to discharge when the rail voltage V sup greater than the first specified voltage threshold (up to V) sup (falls below the second specified threshold). When controller 28 is powered, switch SW5 is closed. When controller 28 is not powered, switch SW5 is normally open to prevent current from flowing from conductor 22 (or the supply rail (V)). sup)) is fed back to the system supply input.

[0026] In Fig. 3 are the switches SW1, SW2, SW3 and SW4 of the H-bridge controller 120 off (when V BATT (is not supplied). When motor M is manually turned, motor M generates a back EMF. Since V BATT If power is not supplied to power supply 24, controller 28 does not provide power to the H-bridge controller 120 or the switch SW5.

[0027] Although it is not powered by the power supply 24 and the controller 28, the motor brake module 121 of the H-bridge controller 120 is configured to detect when the supply rail voltage (V sup ) above the first predefined voltage threshold (e.g., a dynamic brake activation threshold) (e.g., 30 V). The first predefined voltage threshold is greater than V BATT (e.g. 16 V).

[0028] Back EMF flows through the inverse diodes D4 and D1 or D2 and D3 to the bulk capacitor C Bulk to charge. When the first predetermined voltage threshold V TH1 When detected, the H-bridge controller 120 switches on either SW2 and SW4 (or SW1 and SW3) to connect the motor M terminals (to ground or V). sup ) short-circuit and clamp the back EMF across motor M. The H-bridge controller 120 is configured to turn off switches SW2 and SW4 (or SW1 and SW3) when the supply rail voltage (V sup ) falls below a second predetermined voltage (e.g. a dynamic brake deactivation threshold) (e.g. 27 V).

[0029] The soft-clamping circuit 134 conducts a voltage that is in the bulk capacitor C bulk The stored information is available when switch SW5 is off and the supply voltage to the H-bridge controller 120 is the Zener voltage of the Zener diode D. Zenerexceeds. In certain examples, the bulk capacitor C bulk designed to minimize braking time, provide quiet operation and avoid electromagnetic compatibility (EMC) issues.

[0030] The magnitude of the current draw is limited by the resistance R. The Zener voltage D Zener is below the second specified voltage threshold V TH2 of the H-bridge controller 120 selected such that the soft clamping circuit 134 draws current from the supply rail (V sup ) (controlled by the bulk capacitor C) bulk ) until the voltage of the supply rail (V sup ) below the second specified voltage threshold V TH2 falls.

[0031] In certain examples, the first specified voltage threshold V TH1 greater than the second specified voltage threshold V TH2In certain examples, the first predefined voltage threshold VTH1 is in the range of 29 to 31 volts (V) (e.g., 30 V). In certain examples, the second predefined voltage threshold V TH2 smaller than the first specified voltage and larger than V BATT In certain examples, the second specified voltage threshold V is TH2 in the range of 26 to 28 volts (V) (e.g. 27 V).

[0032] In certain examples, V BATT The normal operating battery voltage is in the range of 10 V to 17 V (~16 V). In certain cases, the Zener voltage is greater than V. BATT and smaller than the second specified voltage threshold V TH2 In certain examples, the Zener voltage is in the range of 19 to 21 V (e.g., 20 V).

[0033] The capacitance value of the bulk capacitor C BulkThis is chosen to handle motor transients. The discharge time of the soft-clamp circuit corresponds to the time it takes to discharge the supply voltage V. sup from the first specified voltage threshold V TH1 to the second specified voltage threshold V TH2 to unload. The unloading time is the same - R*CBulk*ln(Second.preset.Clamp.swt−Central clampFirst.preset.Clamp.swt−Central clamp). In certain examples, the discharge time is set to a smaller value than the maximum motor braking time. If the discharge time is too long, the resistance value of resistor R and / or the capacitance value of the bulk capacitor C can be adjusted. Bulk will be reduced.

[0034] Now, with reference to Fig.Figure 5 shows the operation of the H-bridge driver. At 210, the H-bridge controller 120 determines whether the controller 28 is powered. If so, the H-bridge controller 120 controls switches SW1, SW2, SW3, and SW4 to control the motor based on the controller instruction at 214. If 210 is false, the H-bridge controller 120 determines at 218 whether V sup greater than the first specified voltage threshold (V) TH1 ). If 218 is false, the procedure returns to 210. If 218 is true, at 222 the procedure closes switches (S2 and S4) to ground the terminals of motor M (or closes switches (S1 and S3) to connect the terminals of motor M to V sup (to short-circuit). At 226, the H-bridge driver determines whether V sup smaller than the second specified voltage threshold (V) TH2). If 226 is false, the procedure returns to 226. If 226 is true, the procedure opens switches (S2 and S4) (or opens switches (S1 and S3)) and returns to 210.

[0035] The preceding description is merely illustrative and is in no way intended to limit the disclosure, its application, or uses. The comprehensive teachings of the disclosure can be implemented in various forms. While this disclosure contains specific examples, the true scope of protection of the disclosure should therefore not be so limited as to reveal other modifications upon study of the drawings, the description, and the following claims. It is to be understood that one or more steps within a process may be carried out in a different order (or overlapping in time) without altering the principles of the present disclosure.Although each of the embodiments described above has been described with specific features, one or more of these features described with respect to any embodiment of the disclosure may also be implemented in any of the further embodiments and / or combined with its features, even if this combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of protection of this disclosure.

[0036] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, such as "connected," "interlocking," "coupled," "adjacent," "next to," "on top of," "above," "below," and "arranged." Unless explicitly described as "direct," when a relationship between a first and a second element is described in the disclosure above, this relationship can be a direct relationship in which no further intervening elements exist between the first and the second element, or it can be an indirect relationship in which one or more intervening elements (either spatial or functional) exist between the first and the second element.As the expression "at least one of A, B and C" is used here, it should be interpreted as meaning a logical (A OR B OR C) using a non-exclusive logical OR, and should not be interpreted as meaning "at least one of A, at least one of B and at least one of C".

[0037] In the diagrams, the direction of an arrow, indicated by its tip, generally demonstrates the flow of information (such as data or commands) that is relevant for illustration. For example, if element A and element B exchange various pieces of information, but the information transferred from element A to element B is relevant for the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no further information is sent from element B to element A. Furthermore, element B may send requests or acknowledgments of the information sent from element A to element B to element A.

[0038] In this application, including the definitions below, the term "module" or "controller" may be replaced by the term "circuit." The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC); a digital, analog, or mixed analog / digital discrete circuit; a digital, analog, or mixed analog / digital integrated circuit; a combinational logic circuit; a field-programmable gate array (FPGA); a processor circuit (shared, dedicated, or grouped) that executes code; a memory circuit (shared, dedicated, or grouped) that stores code executed by the processor circuit; other suitable hardware components that provide the described functionality; or a combination of some or all of the above, such as in a system-on-a-chip.

[0039] The module may contain one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the internet, a wide area network (WAN), or combinations thereof. The functionality of any given module of this disclosure may be distributed among several modules connected by interface circuits. For example, multiple modules may enable load balancing. In another example, a server module (also known as a remote or cloud module) may perform some functionality on behalf of a client module.

[0040] The term "code," as used above, can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuit" refers to a single-processor circuit that executes some or all of the code from multiple modules. The term "group processor circuit" refers to a processor circuit that, in combination with additional processor circuits, executes some or all of the code from one or more modules. References to multiprocessor circuits include multiprocessor circuits on discrete chips, multiprocessor circuits on a single chip, multiple cores of a single-processor circuit, multiple threads of a single-processor circuit, or a combination of the above.The term shared memory circuit refers to a single memory circuit that stores part or all of the code from multiple modules. The term group memory circuit refers to a memory circuit that, in combination with additional memory, stores part or all of the code from one or more modules.

[0041] The term memory circuit is a subset of the term computer-readable medium. The term computer-readable medium, as used here, does not include transitory electrical or electromagnetic signals that propagate through a medium (such as on a carrier wave); the term computer-readable medium can therefore be considered tangible and non-transient. Non-restrictive examples of a non-transient, tangible computer-readable medium are non-volatile memory circuits (such as a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (such as a static read / write memory circuit or a dynamic read / write memory circuit), magnetic storage media (such as analog or digital magnetic tape or a hard disk drive), and optical storage media (such as...a CD, a DVD or a Blu-ray Disc).

[0042] The devices and methods described in this application can be implemented partially or completely by a special-purpose computer, created by configuring a general-purpose computer to execute one or more specific functions embodied in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a trained technician or programmer.

[0043] Computer programs contain processor-executable instructions stored on at least one non-transient, machine-readable physical medium. Computer programs may also contain or access stored data. Computer programs may include a basic input / output system (BIOS) that interacts with the computer's hardware for a specific purpose, device drivers that interact with specific devices of the computer for a specific purpose, one or more operating systems, user applications, background services, background applications, and so on.

[0044] The computer programs may contain: (i) descriptive text to be parsed, such as... B. HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Name), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a compiler at runtime, etc. For illustrative purposes only, the source code may be written using the syntax of languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language, 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

[1] Engine control system, which includes: a motor controller; a switch that is placed between a battery and a conductor, wherein the motor controller is configured to close the switch when the battery provides battery voltage to the conductor, and to open the switch when the battery does not provide battery voltage to the conductor; a clamping circuit connected to the conductor; a capacitor connected to the conductor; and an H-bridge controller configured to: Selective control of multiple switches to supply alternating current to a motor in response to an instruction from the motor controller; Detecting a voltage on the conductor when the battery is not providing power to the motor controller; Closing at least two of the multiple switches when the voltage on the conductor is greater than a first predetermined voltage threshold, and At least two of the switches will open if the voltage on the conductor is less than a second predetermined voltage threshold. [2] Engine control system according to claim 1, wherein the second predetermined voltage threshold is smaller than the first predetermined voltage threshold and larger than the battery voltage. [3] Motor control system according to claim 1, wherein the clamping circuit includes a resistor and a Zener diode. [4] Motor control system according to claim 3, wherein the Zener diode has a Zener voltage that is smaller than the second predetermined voltage threshold and larger than the battery voltage. [5] Engine control system according to claim 1, wherein the multiple switches comprise the following: a first switch which contains a first terminal which is connected to the conductor; a second switch comprising a first terminal connected to a second terminal of the first switch and a first terminal of the motor, and a second terminal connected to ground; a third switch which includes a first terminal connected to the conductor; a fourth switch which includes a first terminal which is connected to a second terminal of the third switch and a second terminal of the motor, and a second terminal which is connected to ground. [6] Engine control system according to claim 5, wherein the at least two of the multiple switches include the second switch and the fourth switch. [7] Engine control system according to claim 5, wherein the at least two of the multiple switches include the first switch and the third switch. [8] Motor control system according to claim 2, wherein the first predetermined voltage threshold is in the range of 29 volts to 31 volts. [9] Motor control system according to claim 2, wherein the second predetermined voltage threshold is in the range of 26 volts to 28 volts. [10] Motor control system according to claim 4, wherein the Zener voltage is in the range of 19 to 21 volts and the battery voltage is in the range of 15 to 17 volts.

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