Electromagnetic clutch drive circuit applied to motor controller and motor controller

Abstract

The invention provides an electromagnetic clutch driving circuit applied to a motor controller and the motor controller, and relates to the technical field of motor control, and the electromagnetic clutch driving circuit comprises a main control chip which is used for outputting a control instruction to an adjustable buck-boost module and sampling the output current of an electromagnetic clutch coil; the adjustable buck-boost module communicates with the main control chip and controls output of variable voltage according to the control instruction; the electromagnetic clutch is connected with the adjustable buck-boost module, so that the adjustable buck-boost module outputs variable voltage and generates variable current after passing through a coil of the electromagnetic clutch to control the connection and separation of the electromagnetic clutch; the current sampling circuit is used for sampling output current of a coil of the electromagnetic clutch and feeding back the output current to the main control chip; the main control chip sends a control instruction to the adjustable buck-boost module according to feedback of the current sampling circuit so as to control current passing through a coil of the electromagnetic clutch in real time, and the problems that an existing electromagnetic clutch drive circuit is large in number of devices and complex in arrangement and operation are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor control, and in particular to an electromagnetic clutch drive circuit and a motor controller used in a motor controller. Background Art

[0002] Electromagnetic clutches are commonly used in automobile air-conditioning compressors, continuously variable transmissions, brakes and other equipment. They can achieve power transmission and isolation to ensure the normal operation and control of the automobile. The electromagnetic clutch control method is to control the clutch engagement, retention and separation by controlling the current on and off and amplitude of the coil. Most of the existing electromagnetic clutch drive circuits are arranged with boost circuits and buck circuits, sampling the high-side or low-side current, and controlling the output voltage through pulse width modulation to adjust the coil current or the current size. It is also necessary to manually set the duty cycle or frequency of the PWM signal, or rely on sensor feedback control, with many circuit components and a relatively complex layout. Summary of the invention

[0003] In order to overcome the above technical defects, the purpose of the present invention is to provide an electromagnetic clutch drive circuit and a motor controller used in a motor controller to solve the problem that the existing electromagnetic clutch drive circuit has many components and complex layout and operation.

[0004] The invention discloses an electromagnetic clutch driving circuit, comprising:

[0005] The main control chip is used to output control instructions to the adjustable buck-boost module and sample the output current of the electromagnetic clutch coil;

[0006] An adjustable buck-boost module communicates with the main control chip and controls the output variable voltage according to control instructions;

[0007] An electromagnetic clutch connected to the adjustable buck-boost module, so that the adjustable buck-boost module outputs a variable voltage that passes through the coil of the electromagnetic clutch to generate a variable current to control its engagement and disengagement;

[0008] A current sampling circuit samples the output of the coil of the electromagnetic clutch and feeds back the current to the main control chip;

[0009] The main control chip sends a control instruction to the adjustable buck-boost module according to the feedback of the current sampling circuit, so as to control the current passing through the coil of the electromagnetic clutch in real time.

[0010] Preferably, the adjustable buck-boost module comprises a synchronous four-switch buck-boost converter with integrated MOSFET devices;

[0011] The on and off of the MOSFET device is controlled according to the control instruction of the main control chip to control the output variable voltage.

[0012] Preferably, the adjustable buck-boost module comprises a buck-boost circuit and a communication processing module formed by capacitors, inductors, MOSFET devices, and diodes connected in series and / or in parallel;

[0013] The on and off of the MOSFET device is controlled according to the control instruction of the main control chip to control the output variable voltage.

[0014] Preferably, the adjustable buck-boost module further includes a peripheral configuration circuit.

[0015] Preferably, the current sampling circuit comprises a sampling resistor and a differential operational amplifier circuit.

[0016] Preferably, the differential operational amplifier circuit adopts a built-in gain resistor or an external gain resistor.

[0017] Preferably, the main control chip and the adjustable buck-boost module are based on the SPI protocol or I 2 C protocol to establish communication.

[0018] The present invention also provides a motor controller, which uses any of the electromagnetic clutch drive circuits described above.

[0019] Compared with the prior art, the above technical solution has the following beneficial effects:

[0020] The present application provides an electromagnetic clutch drive circuit and a motor controller for use in a motor controller, in which a main control chip communicates with an adjustable buck-boost module, and an output current is determined by a current sampling circuit located at the output of the electromagnetic clutch coil and fed back to the main control chip. The main control chip controls the operation of the adjustable buck-boost module according to the output current, thereby dynamically adjusting the current passing through the electromagnetic clutch inductor and coil in real time to control the engagement, retention and separation of the clutch, thereby solving the problem that the existing electromagnetic clutch drive circuit has a large number of components and complex layout and operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A schematic diagram of the circuit structure of an electromagnetic clutch drive circuit and a motor controller embodiment used in a motor controller according to the present invention;

[0022] Figure 2 A schematic diagram of the circuit structure of a buck-boost converter exemplified in an adjustable buck-boost module in an electromagnetic clutch drive circuit used in a motor controller and an embodiment of a motor controller according to the present invention;

[0023] Figure 3 It is a structural schematic diagram of a buck-boost circuit exemplified in an electromagnetic clutch drive circuit used in a motor controller and another adjustable buck-boost module in an embodiment of the motor controller described in the present invention.

[0024] Reference numerals:

[0025] 1- Main control chip; 2- Adjustable buck-boost module; 3- Electromagnetic clutch; 4- Current sampling circuit; 5- Peripheral configuration circuit. DETAILED DESCRIPTION

[0026] The advantages of the present invention are further described below in conjunction with the accompanying drawings and specific embodiments.

[0027] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0028] The terms used in this disclosure are for the purpose of describing specific embodiments only and are not intended to limit the disclosure. The singular forms of "a", "said" and "the" used in this disclosure and the appended claims are also intended to include plural forms unless the context clearly indicates otherwise. It should also be understood that the term "and / or" used herein refers to and includes any or all possible combinations of one or more associated listed items.

[0029] It should be understood that although the terms first, second, third, etc. may be used in the present disclosure to describe various information, such information should not be limited to these terms. These terms are only used to distinguish the same type of information from each other. For example, without departing from the scope of the present disclosure, the first information may also be referred to as the second information, and similarly, the second information may also be referred to as the first information. Depending on the context, the word "if" as used herein may be interpreted as "at the time of" or "when" or "in response to determining".

[0030] In the description of the present invention, it is necessary to understand that the terms "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0031] In the description of the present invention, unless otherwise specified and limited, it should be noted that the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a mechanical connection or an electrical connection, or it can be the internal connection between two components. It can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to the specific circumstances.

[0032] In the following description, the suffixes such as "module", "component" or "unit" used to represent elements are only used to facilitate the description of the present invention, and have no specific meanings. Therefore, "module" and "component" can be used interchangeably.

[0033] Embodiment: The present invention discloses an electromagnetic clutch drive circuit used in a motor controller. Different from the existing method of controlling current by pulse width modulation control, which requires the arrangement of more devices, the present invention communicates with the adjustable buck-boost module through the main control chip to issue instructions to control the output current, and can perform real-time and autonomous control based on low-side current feedback. For details, see Figure 1 ,include:

[0034] The main control chip is used to output control instructions to the adjustable buck-boost module and sample the output current of the electromagnetic clutch coil;

[0035] An adjustable buck-boost module communicates with the main control chip and controls the output variable voltage according to control instructions;

[0036] An electromagnetic clutch connected to the adjustable buck-boost module, so that the adjustable buck-boost module outputs a variable voltage that passes through the coil of the electromagnetic clutch to generate a variable current to control its engagement and disengagement;

[0037] A current sampling circuit samples the inductance of the electromagnetic clutch and the output of the coil, and feeds back to the main control chip;

[0038] The main control chip sends a control instruction to the adjustable buck-boost module according to the feedback of the current sampling circuit, so as to control the current passing through the coil of the electromagnetic clutch in real time.

[0039] It is understandable that the main control chip controls the adjustable buck-boost module by enabling (EN signal) to turn it on or off, and adjusting the precise output of the adjustable buck-boost module (such as the required 11.4V output).

[0040] In this embodiment, the main control chip can also send an EN signal to enable or shut down the adjustable buck-boost module, and detect the electromagnetic clutch coil current in real time through the current sampling circuit located at the low-side current (that is, the coil output side of the electromagnetic clutch, assuming that the input side of the coil is the high-side current, where the high-side current and the low-side current only represent relative high and low), and then adjust the variable voltage output by the adjustable buck-boost module through real-time communication to perform real-time closed-loop control of the electromagnetic clutch current.

[0041] It is understandable that for the above-mentioned variable voltage, in the new power supply motor controller, it is usually required that the input low-voltage power supply voltage is between 9 and 18V to be able to normally control the on and off of the electromagnetic clutch. However, since the equivalent resistance RL of the electromagnetic clutch changes positively with the change of temperature, taking the currently actually adapted electromagnetic clutch as an example, the RL resistance at 25C is 3ohm, and the RL value at 200C is 5ohm, and the required pull-in current is 3.8A, which means that the theoretical output voltage variation range is 11.4 to 19V. Therefore, a corresponding adjustable buck-boost module is required to convert the input 9 to 18V into an output variable voltage of 11.4 to 19V.

[0042] In this embodiment, it should be noted that the above-mentioned adjustable buck-boost module is a communicative and adjustable buck-boost circuit () that can produce a variable voltage. Specifically, the buck-boost converter with communication function can also be a buck-boost circuit with integrated communication processing module. The electromagnetic clutch can be controlled without arranging microcontroller units, PWM chips and other components. The circuit layout is simple and can be autonomously and instantly controlled by the main control chip.

[0043] As a supplement, the main control chip can be equipped with predetermined software programs, such as performing predetermined controls at regular intervals, or autonomously outputting control signals based on the current feedback from the current sampling circuit. Furthermore, it can even run / connect to the processing system to output data for data processing, etc., and can be arranged according to actual scenarios.

[0044] In a preferred embodiment, the adjustable buck-boost module includes a synchronous four-switch buck-boost converter with integrated MOSFET devices; specifically, as an example, a buck-boost converter such as TPS55288-Q1 (such as Figure 2 ) and the synchronous four-switch buck-boost converter of MPQ4232. It can be understood that other existing buck-boost converters that can achieve communication and adjustment can also be used in the buck-boost circuit of this embodiment, and the on and off of the MOSFET device is controlled according to the control instructions of the main control chip to control the output variable voltage.

[0045] As an example, the TPS55288-Q1 buck-boost DC-DC converter can operate in a wide input voltage range of 2.7V to 36V, and the output variable voltage range is 0.8V to 22V. It can smoothly switch between buck mode, boost mode, and buck-boost mode, and adjust according to the input voltage and the set output voltage.

[0046] In another preferred embodiment, different from the above-mentioned method of directly applying a buck-boost converter, an adjustable circuit with integrated communication is used. Specifically, the adjustable buck-boost module includes a buck-boost circuit and a communication processing module formed by capacitors, inductors, MOSFET devices, and diodes connected in series and / or in parallel; the on and off of the MOSFET device is controlled according to the control instructions of the main control chip to control the output variable voltage.

[0047] As an example, it can be arranged as follows Figure 3 As shown, the input end is connected to the inductor L1 and the capacitor Ci, the output ends of the inductor L1 and the capacitor Ci are both connected to the MOSFET device Q1, the output end of the inductor L1 is also connected to the input end of the capacitor C1, the output end of the capacitor C1 and the output end of the capacitor Ci are respectively connected to the two ends of the inductor L2, the output end of the capacitor C1 is connected to one end of the capacitor Co through the diode D1, the capacitor Ci is connected to one end of the capacitor L2 and is also connected to the other end of the capacitor Co, thereby forming an adjustable buck-boost module, and integrating a communication processing module, adjusting the input according to the received control command, and controlling the on and off of the MOSFET device Q1, thereby forming a control output variable voltage.

[0048] The arrangement (quantity and position) and control of the MOSFET devices in any of the above-mentioned adjustable buck-boost modules can be adjusted according to the actual scenario or application device.

[0049] In this embodiment, the control is realized by communicating between the main control chip and any of the above-mentioned adjustable buck-boost modules. 2 C protocol is used to establish communication. The synchronous four-switch buck-boost converters of TPS55288-Q1 and MPQ4232 in the above examples can establish communication through this protocol. In addition, when other buck-boost converters or communication processing modules are used, other communication protocols can also be used in combination.

[0050] Based on the above, the adjustable buck-boost module can integrate functions such as output short circuit to power supply, short circuit to ground, overcurrent protection, overtemperature protection, and output short circuit, which can be independently realized through the above-mentioned buck-boost converter, or through the various relocation arrangements of the above-mentioned adjustable buck-boost module, thereby reducing the overall circuit complexity.

[0051] As an example, the main control chip and the adjustable buck-boost module are connected via I 2 C protocol is used to establish communication, the main control chip outputs E signal to start the adjustable buck-boost module, the current sampling circuit collects the inductance of the electromagnetic clutch and the output current of the coil and feeds them back to the main control chip, and generates a control instruction according to the output current of the coil to send it to the adjustable buck-boost module. The adjustable buck-boost module dynamically adjusts its output variable voltage in real time according to the control instruction (including the target output current value); when the main control chip detects a fault signal, it immediately controls the adjustable buck-boost module to disconnect.

[0052] In a preferred embodiment, based on any of the above-mentioned adjustable buck-boost modules, the adjustable buck-boost module may further include a peripheral configuration circuit. It is understandable that the peripheral configuration circuit may exchange signals and / or transmit data with the main control chip, or may also be used to support the normal operation of the above-mentioned buck-boost converter or buck-boost circuit, or may also monitor the above-mentioned adjustable buck-boost circuit. Specifically, as an example, the peripheral configuration circuit may include but is not limited to input / output devices, memory, clock circuit, communication interface, sensor, capacitor inductor, diode, etc. It is an important part of realizing the functional expansion of the adjustable boost circuit and the interaction with the external environment.

[0053] In this embodiment, as described above, the adjustable buck-boost module outputs a variable voltage output current that generates a variable current after passing through the inductance and coil of the electromagnetic clutch, and current sampling is performed on the low side (coil output) to feed back to the main control chip, so as to realize real-time monitoring of the electromagnetic clutch output by the main control chip, thereby controlling the adjustable buck-boost module according to the output current. It can be understood that in this embodiment, there is no need to rely on pulse width modulation for output control, and therefore there is no need to sample the high-side current or to sample the current at multiple locations. Only the low-side current needs to be sampled, thereby simplifying the circuit layout and reducing safety risks during use.

[0054] Based on the above, specifically, the current sampling circuit includes a sampling resistor and a differential op amp circuit. The differential op amp circuit is mainly used to amplify the difference between the voltages of the two input terminals. It is widely used in signal amplification, sensor measurement, filter design, signal separation, and communication systems. It can amplify weak sensor signals and improve the sensitivity and accuracy of the signal. Specifically, in this embodiment, as an example, the differential op amp circuit uses a built-in gain resistor or an external gain resistor, which can be configured according to the actual application scenario. It can be understood that other circuits that can realize the differential op amp function, or differential op amp circuits integrating other functions can also be used for this.

[0055] Based on the above, the electromagnetic clutch drive circuit provided in this embodiment communicates with the adjustable buck-boost module through the main control chip, and controls the adjustable buck-boost module to be enabled (EN signal) or disabled based on the control instruction. After the controller is enabled, the real-time output current of the coil of the electromagnetic clutch can also be determined through the current sampling circuit, and the operation and output variable voltage of the adjustable buck-boost module can be controlled according to the real-time output current, thereby adjusting the current passing through the electromagnetic clutch coil to control the engagement, retention and separation of the clutch.

[0056] When the main control chip turns off the output of the adjustable buck-boost module (or can be arranged as an adjustable buck-boost switching power supply) through the EN signal, the inductor current in the electromagnetic clutch can be freewheeled through the body diode of the built-in MOSFET in the buck-boost circuit. The adjustable buck-boost module can be set to have overcurrent and short-circuit protection capabilities, and current sampling can be adjusted from the high side to the low side to reduce circuit costs.

[0057] Specifically, the main control chip can also be set with a monitoring function, that is, when the main control chip detects a FAULT signal (fault feedback signal), when (the adjustable buck-boost module detects internal or external abnormalities such as output overcurrent, short circuit or overtemperature) or the I_ADC (the input signal of the analog-to-digital converter (ADC), that is, the input signal of the adjustable buck-boost module / the signal fed back by the current sampling circuit) signal exceeds the set value, the main control chip can shut down the output of the adjustable buck-boost module through the EN signal.

[0058] This embodiment also provides a motor controller, which uses the electromagnetic clutch drive circuit described in any of the above items, and can be applied to new energy motor controllers, with complete protection and operation functions, compact layout, a small number of components, high reliability, and a simple circuit structure. The main control chip can be software-controlled according to continuous current sampling, and the clutch engagement, retention, and separation circuits are controlled by the current on and off and amplitude of the coil. The layout is simple and easy to operate. Furthermore, it can also be connected with other components / devices to be suitable for the layout of different implementation scenarios.

[0059] It should be noted that the embodiments of the present invention have better practicability and do not impose any form of limitation on the present invention. Any technician familiar with the field may use the technical content disclosed above to change or modify it into an equivalent effective embodiment. However, any modification or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An electromagnetic clutch drive circuit used in a motor controller, characterized in that: include: The main control chip is used to output control instructions to the adjustable buck-boost module and sample the output current of the electromagnetic clutch coil; An adjustable buck-boost module communicates with the main control chip and controls the output variable voltage according to control instructions; An electromagnetic clutch connected to the adjustable buck-boost module, so that the adjustable buck-boost module outputs a variable voltage that passes through the coil of the electromagnetic clutch to generate a variable current to control its engagement and disengagement; The current sampling circuit samples the output of the coil of the electromagnetic clutch and feeds back to the main control chip; the main control chip sends a control instruction to the adjustable buck-boost module according to the feedback of the current sampling circuit to control the current passing through the coil of the electromagnetic clutch in real time.

2. The electromagnetic clutch drive circuit according to claim 1, characterized in that: The adjustable buck-boost module includes a synchronous four-switch buck-boost converter with integrated MOSFET devices; The on and off of the MOSFET device is controlled according to the control instruction of the main control chip to control the output variable voltage.

3. The electromagnetic clutch drive circuit according to claim 1, characterized in that: The adjustable buck-boost module includes a buck-boost circuit formed by capacitors, inductors, MOSFET devices, and diodes connected in series and / or in parallel, and a communication processing module; The on and off of the MOSFET device is controlled according to the control instruction of the main control chip to control the output variable voltage.

4. The electromagnetic clutch drive circuit according to claim 2 or 3, characterized in that: The adjustable buck-boost module also includes a peripheral configuration circuit.

5. The electromagnetic clutch drive circuit according to claim 1, characterized in that: The current sampling circuit includes a sampling resistor and a differential operational amplifier circuit.

6. The electromagnetic clutch drive circuit according to claim 1, characterized in that: The differential operational amplifier circuit adopts a built-in gain resistor or an external gain resistor.

7. The electromagnetic clutch drive circuit according to claim 1, characterized in that: The main control chip and the adjustable buck-boost module are based on the SPI protocol or I 2 C protocol to establish communication.

8. A motor controller, characterized in that: An electromagnetic clutch drive circuit as described in any one of claims 1 to 7 is used.

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