Rotary transformer driving protection circuit

Abstract

The invention discloses a rotary transformer driving protection circuit, which comprises a signal output unit used for outputting an initial rotary transformer driving signal; the input end of the signal amplification unit is connected with the output end of the signal output unit, and the signal amplification unit is used for amplifying the signal voltage value and the signal current value corresponding to the received initial resolver driving signal to obtain a target resolver driving signal; the overcurrent adjusting unit is used for determining a preset current value according to element parameters of the rotary transformer driving protection circuit; and the overcurrent control unit is electrically connected with the signal amplification unit and the overcurrent adjusting unit and is used for reducing the signal current value of the target rotary transformer driving signal output by the signal amplification unit after the signal current value of the target rotary transformer driving signal exceeds a preset current value. The over-current protection circuit has a current-limiting protection function, and compared with the prior art, the over-current protection circuit can adjust the threshold value of the protection current more finely and independently, the over-current protection function is more sensitive, and the triggering time is shorter.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and more specifically, to a resolver drive protection circuit. Background Art

[0002] New energy vehicles refer to vehicles that use unconventional vehicle fuels as their power source or use conventional vehicle fuels but have new on-board power devices. They integrate advanced technologies in vehicle power control and drive to form vehicles with advanced technical principles, new technologies and new structures. Types of new energy vehicles include but are not limited to pure electric vehicles, hybrid vehicles, fuel cell vehicles and extended-range electric vehicles.

[0003] A motor is a device that converts electrical energy into mechanical energy. It is one of the core components of a car's electrical system and is mainly used as a power source for the car. The motor on a car usually includes an electromagnet winding or a distributed stator winding to generate a magnetic field and a rotating armature or rotor. The motor can convert electrical energy into mechanical energy to enable the car to operate normally.

[0004] A resolver (also known as a resolver sensor or rotary transformer) is a position sensor that can accurately detect the position, direction and speed of the rotor on a motor. It consists of two parts: a stator winding and a rotor winding. The stator winding inputs an excitation voltage, and the rotor winding obtains an induced voltage through electromagnetic induction. The working principle of the resolver is based on the motor controller inputting alternating current into the excitation coil to generate signals of a specific frequency. These signals change as the rotor winding rotates. By analyzing these changes, the absolute position, rotation direction and speed of the rotor can be estimated. This precise measurement enables the motor controller to accurately control the speed and direction of the motor based on the real-time data provided by the resolver.

[0005] The signal source of the resolver can be the main control MCU (Microcontroller Unit, also known as: single-chip microcomputer, single-chip microcomputer), which provides a driving signal to the resolver. The driving signal controls whether the resolver works. The main control MCU and the resolver are usually connected through a resolver driving circuit. The resolver driving circuit has an enhancing effect on the driving signal provided by the main control MCU. When the enhancing effect is too large, the driving voltage is over-voltage or over-current, which can easily burn out the resolver driving circuit. In order to avoid this problem, the resolver driving circuit needs to be current limited and over-voltage protected.

[0006] Reference Figure 1 As shown, Figure 1It is a schematic diagram of a current limiting circuit for the power supply input of a resolver signal conditioning circuit in the prior art. A Chinese patent document (application number 202321779245.X, application date 2023.07.07) discloses a current limiting resolver circuit, including a resolver signal conditioning circuit and a VCC power supply. The input end of the resolver signal conditioning circuit inputs a reference SIN waveform signal and a COS waveform signal, and the output end of the resolver signal conditioning circuit outputs an excitation signal to a resolver transformer; the VCC power supply is used to provide power for the resolver signal conditioning circuit, and the VCC power supply is connected to the power supply end of the resolver signal conditioning circuit through a current limiting circuit; the current limiting circuit includes a transistor q 1', q2' and resistors r1', r2'; VCC power supply is connected to the collector of transistor q1'; the emitter of transistor q1' is connected to the base of transistor q2'; the base of transistor q1' is connected to the collector of transistor q2'; the base of transistor q1' is connected to the collector of transistor q1' via resistor r1'; the base of transistor q2' is connected to the emitter of transistor q2' via resistor r2'; the emitter of transistor q2' leads to the output power supply end for connecting to the power supply input end of the rotary signal conditioning circuit; the emitter of transistor q2' is grounded via capacitor C'; resistor r3' is set in parallel at both ends of capacitor C'. This solution cannot independently adjust the threshold of the protection current, and the current limiting effect is general. Therefore, it is a technical problem that needs to be solved urgently. Summary of the invention

[0007] In view of this, the present invention provides a resolver drive protection circuit, which enhances the effect of the current limiting protection function while ensuring the current limiting protection function.

[0008] The present application provides a resolver drive protection circuit, comprising:

[0009] A signal output unit, used for outputting an initial resolver drive signal;

[0010] A signal amplifying unit, whose input end is connected to the output end of the signal output unit, is used to amplify the signal voltage value and signal current value corresponding to the received initial resolver drive signal to obtain a target resolver drive signal;

[0011] An overcurrent regulating unit, used to determine a preset current value according to component parameters of the resolver drive protection circuit;

[0012] The overcurrent control unit is electrically connected to the signal amplification unit and the overcurrent regulation unit, and is used to reduce the signal current value of the target resolver drive signal output by the signal amplification unit after the signal current value of the target resolver drive signal exceeds a preset current value.

[0013] Optionally, the signal amplification unit includes a push-pull amplifier circuit for amplifying a signal current value corresponding to the initial resolver drive signal;

[0014] The overcurrent control unit includes an overcurrent switch tube group; the input end of the overcurrent switch tube group is electrically connected to the control end of the first amplifying triode in the push-pull amplifying circuit, and the output end of the overcurrent switch tube group is electrically connected to the control end of the second amplifying triode in the push-pull amplifying circuit;

[0015] One end of the overcurrent regulating unit is electrically connected to the control end of the overcurrent switch tube group, and the other end of the overcurrent regulating unit is electrically connected to the output end of the first amplifying triode and the input end of the second amplifying triode;

[0016] When the signal current value of the target resolver drive signal output by the push-pull amplifier circuit exceeds the preset current value, the overcurrent regulation unit controls the overcurrent switch tube group to turn on, so that the output current of the first amplifying transistor is reduced and the output current of the second amplifying transistor is increased.

[0017] Optionally, the overcurrent switch tube group includes a first control transistor and a second control transistor;

[0018] The input end of the first control triode is electrically connected to the control end of the first amplifying triode, the output end of the first control triode is electrically connected to the input end of the second control triode, and the output end of the second control triode is electrically connected to the control end of the second amplifying triode;

[0019] The overcurrent regulating unit includes a first regulating member and a second regulating member;

[0020] The input end of the first adjusting member is electrically connected to the output end of the first amplifying transistor, the output end of the first adjusting member is electrically connected to the control end of the first control transistor, the input end of the second adjusting member is electrically connected to the input end of the second amplifying transistor, and the output end of the second adjusting member is electrically connected to the control end of the second control transistor;

[0021] When the signal current value of the target resolver drive signal exceeds the preset current value, the output voltages of the first adjustment element and the second adjustment element reach the turn-on voltages of the first control transistor and the second control transistor, respectively.

[0022] Optionally, the first adjustment member includes a first adjustment resistor;

[0023] The input end of the first regulating resistor is electrically connected to the output end of the first amplifying transistor, and the output end of the first regulating resistor is electrically connected to the control end of the first control transistor;

[0024] The second adjusting member includes a second adjusting resistor;

[0025] The input end of the second regulating resistor is electrically connected to the input end of the second amplifying transistor, and the output end of the second regulating resistor is electrically connected to the control end of the second control transistor;

[0026] When the signal current value of the target resolver drive signal exceeds the preset current value, the voltage on the first adjustment resistor reaches the turn-on voltage of the first control transistor, and the voltage on the second adjustment resistor reaches the turn-on voltage of the second control transistor.

[0027] Optionally, the overcurrent control unit further includes a first control diode and a second control diode connected in series with each other;

[0028] The anode of the first control diode is electrically connected to the output end of the first control transistor;

[0029] The cathode of the second control diode is electrically connected to the input end of the second control transistor;

[0030] The anode of the second control diode and the cathode of the first control diode are electrically connected to the output end of the push-pull amplifier circuit.

[0031] Optionally, the push-pull amplifier circuit further includes an operational amplifier;

[0032] The positive input terminal of the operational amplifier is electrically connected to the power supply, the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the signal output unit, and the output terminal of the operational amplifier is electrically connected to the control terminal of the first amplifying transistor and the control terminal of the second amplifying transistor respectively.

[0033] Optionally, the signal amplifying unit includes a voltage amplifying circuit, and the voltage amplifying circuit includes a voltage amplifying capacitor and a voltage amplifying resistor;

[0034] The voltage amplifying capacitor and the voltage amplifying resistor are connected in parallel, and the positive electrode of the voltage amplifying capacitor is electrically connected to the output end of the signal output unit, and the negative electrode of the voltage amplifying capacitor is electrically connected to the output end of the push-pull amplifier circuit.

[0035] Optionally, the resolver drive protection circuit further includes an overvoltage detection unit;

[0036] The input end of the overvoltage detection unit is electrically connected to the output end of the signal amplification unit, and is used to reduce the signal voltage value of the target resolver drive signal output by the signal amplification unit after the signal voltage value of the target resolver drive signal exceeds a preset voltage value.

[0037] Optionally, the overvoltage detection unit includes an overvoltage detection diode;

[0038] The anode of the overvoltage detection diode is electrically connected to the output end of the signal amplification unit, and the cathode of the overvoltage detection diode is electrically connected to the power supply.

[0039] Optionally, the signal output unit includes a signal generator and a second-order passive resistor-capacitor filter;

[0040] The signal generator is used to output an initial resolver driving signal;

[0041] The input end of the second-order passive resistor-capacitor filter is electrically connected to the output end of the signal generator, and the output end of the second-order passive resistor-capacitor filter is electrically connected to the input end of the signal amplification unit.

[0042] Compared with the prior art, the resolver drive protection circuit provided by the present invention achieves at least the following beneficial effects:

[0043] The resolver drive protection circuit provided by the present invention processes the initial resolver drive signal received from the microcontroller unit to obtain a target resolver drive signal, and then provides the target resolver drive signal to the resolver to make it work. The microcontroller unit and the resolver can both be internal structures of the new energy vehicle. The processing method includes increasing the signal current value and the signal voltage value of the initial resolver drive signal. Compared with the circuit in the prior art, the resolver drive protection circuit adds an overcurrent regulation unit. The overcurrent regulation unit can play a current limiting role to avoid the signal current value of the target resolver drive signal provided to the resolver being too large. By adjusting the overcurrent regulation unit, the signal current value of the target resolver drive signal can be changed. Compared with the prior art, the resolver drive protection circuit can more finely and independently adjust the threshold of the protection current, and the overcurrent protection function is more sensitive and the triggering time is shorter.

[0044] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0045] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0047] Figure 1 It is a schematic diagram of a current limiting circuit for a power supply input of a resolver signal conditioning circuit in the prior art;

[0048] Figure 2 It is a circuit diagram of a resolver drive protection circuit provided by the present invention;

[0049] Figure 3 This is a circuit diagram of another resolver drive protection circuit provided by the present invention. DETAILED DESCRIPTION

[0050] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0051] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0052] Technologies, methods, and devices known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and devices should be considered as part of the specification.

[0053] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0054] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0055] Reference Figure 2 , Figure 2 The present invention provides a circuit diagram of a rotary transformer drive protection circuit.

[0056] Example 1

[0057] Reference Figure 2 As shown, this embodiment provides a resolver drive protection circuit, including a signal output unit, the signal output unit is used to output an initial resolver drive signal, the output end of the signal output unit is electrically connected to the input end of the signal amplification unit, and the signal output unit will be described later.

[0058] Continue to refer to Figure 2 As shown, the resolver drive protection circuit provided in this embodiment also includes a signal amplifying unit, the input end of the signal amplifying unit is electrically connected to the output end of the signal output unit, and is used to amplify the signal voltage value and signal current value corresponding to the received initial resolver drive signal to obtain the target resolver drive signal; the signal amplifying unit includes a push-pull amplifying circuit and a voltage amplifying circuit, the push-pull amplifying circuit is used to amplify the signal current value corresponding to the initial resolver drive signal, the voltage amplifying circuit is used to amplify the signal voltage value corresponding to the initial resolver drive signal, the push-pull amplifying circuit and the voltage amplifying circuit are connected in parallel, the input end of the push-pull amplifying circuit and the input end of the voltage amplifying circuit are both electrically connected to the output end of the signal output unit, and the output end of the push-pull amplifying circuit is electrically connected to the output end of the voltage amplifying circuit.

[0059] Continue to refer to Figure 2As shown, the resolver drive protection circuit provided in this embodiment also includes an overcurrent regulation unit, which is electrically connected to the push-pull amplifier circuit and the overcurrent control unit, and the overcurrent regulation unit is used to determine the preset current value according to the component parameters of the resolver drive protection circuit; the resolver drive protection circuit provided in this embodiment also includes an overcurrent control unit, which is electrically connected to the signal amplification unit and the overcurrent regulation unit, and is used to reduce the signal current value of the target resolver drive signal output by the signal amplification unit after the signal current value of the target resolver drive signal exceeds the preset current value.

[0060] In an alternative embodiment, continue to refer to Figure 2 As shown, the push-pull amplifier circuit includes a first amplifier transistor Q1, a second amplifier transistor Q2 and an operational amplifier Op-amp. It should be noted that:

[0061] (1) An operational amplifier (abbreviated as "op amp") is a high-performance electronic component and a circuit unit with a very high amplification factor. Its output signal can be the result of mathematical operations such as addition, subtraction, differentiation, and integration of the input signal. It is suitable for occasions requiring high precision and high-speed response. The structure and working principle of the operational amplifier are all existing technologies in this field and will not be described in detail here.

[0062] (2) The operational amplifier has five ports, namely, the positive input, the inverting input, the positive power supply, the negative power supply and the output. The positive input (also called the non-inverting input) receives the positive part of the input signal, which determines the phase and gain of the output signal and has the same phase as the output signal. The inverting input (also called the negative input) receives the inverting part of the input signal, which determines the phase and gain of the output signal and has an opposite phase to the output signal. The positive power supply provides a positive power supply voltage to ensure the normal operation of the operational amplifier. The negative power supply provides a negative power supply voltage. The negative power supply and the positive power supply together constitute the operating voltage of the operational amplifier and can usually be grounded. The output is the output signal port of the operational amplifier. After amplifying the difference between the input signal at the positive input and the inverting input, the amplitude and phase of the output signal depend on the difference in the input signal and the gain of the operational amplifier. The operational amplifier implements various processing such as signal amplification, operation and transformation through these five ports.

[0063] (3) Grounding is represented as GND in the figure. Grounding is used to direct current to the ground and reduce the magnitude of the current in the circuit. The working principle and function of grounding are all existing technologies in the field and will not be repeated here.

[0064] Continue to refer to Figure 2As shown, the non-inverting input terminal of the operational amplifier Op-amp is electrically connected to the power supply VCC_RDC, the inverting input terminal of the operational amplifier Op-amp is electrically connected to the output terminal of the signal output unit, and the output terminal of the operational amplifier Op-amp is electrically connected to the control terminal of the first amplifying transistor Q1 and the control terminal of the second amplifying transistor Q2, respectively. Through the mutual cooperation between the first amplifying transistor Q1, the second amplifying transistor Q2 and the operational amplifier Op-amp, the signal current value corresponding to the initial resolver drive signal is amplified to obtain the target resolver drive signal.

[0065] Optionally, continue to refer to Figure 2 As shown, the non-inverting input terminal of the operational amplifier Op-amp is connected in series with the power supply VCC_RDC through the sixteenth resistor R16, the side of the sixteenth resistor R16 close to the non-inverting input terminal is connected to one end of the seventeenth resistor R17, the other end of the seventeenth resistor R17 is grounded GND, the side of the sixteenth resistor R16 close to the non-inverting input terminal is connected to the first electrode of the seventh capacitor C7, the second electrode of the seventh capacitor C7 is grounded GND, the side of the sixteenth resistor R16 close to the non-inverting input terminal is connected to the first electrode of the eighth capacitor C8, the second electrode of the eighth capacitor C8 is grounded GND, the sixteenth resistor R16, the seventeenth resistor R17, the seventh capacitor C7 and the eighth capacitor C8 can be regarded as an integral structure, which is used to provide a reference voltage for the operational amplifier Op-amp working in reverse input; the positive power supply terminal of the operational amplifier Op-amp can be grounded GND through the sixth capacitor C6, and the positive power supply terminal of the operational amplifier Op-amp can be electrically connected to the power supply VCC_RDC, and the negative power supply terminal of the operational amplifier Op-amp is grounded GND.

[0066] Optionally, continue to refer to Figure 2As shown, the input end of the first amplifying transistor Q1 (the collector of the first amplifying transistor Q1) is connected to the power supply VCC_RDC, the control end of the first amplifying transistor Q1 (the base of the first amplifying transistor Q1) is connected in series with the power supply VCC_RDC through the first diode D1, the control end of the first amplifying transistor Q1 is connected to the cathode of the first diode D1, a first parallel resistor is connected in series between the anode of the first diode D1 and the power supply VCC_RDC, the first parallel resistor includes a sixth resistor R6 and a seventh resistor R7 connected in parallel, the sixth resistor R6 and the seventh resistor R7 can connect the first diode D1 to the power supply VCC_RDC. D1 plays the role of voltage division and current limiting. The power supply VCC_RDC can supply power to the input end and the control end of the first amplifying transistor Q1 respectively. By setting the sixth resistor R6, the seventh resistor R7 and the first diode D1, the voltage and current of the control end of the first amplifying transistor Q1 can be set, so as to realize the signal amplification and switching function of the first amplifying transistor Q1 in a manner of controlling a large current with a small current; it should be noted that the first parallel resistor may include the sixth resistor R6 and the seventh resistor R7 connected in parallel, or the first parallel resistor may be set to a single resistor (not shown in the figure), which is not specifically limited here.

[0067] Optionally, continue to refer to Figure 2 As shown, the anode of the first diode D1 is connected to the output end of the operational amplifier Op-amp through the eighth resistor R8, the fourth diode D4, and the fifth diode D5 in sequence. The eighth resistor R8 is located on the side of the fourth diode D4 close to the first diode D1. The anode of the fourth diode D4 is connected to the eighth resistor R8, and the cathode of the fourth diode D4 is connected to the anode of the fifth diode D5. The circuit where the eighth resistor R8, the fourth diode D4, and the fifth diode D5 are located can share the current flowing through the anode of the first diode D1, and the static operating point voltage of the first amplifying transistor Q1 can be set at the same time. The operational amplifier Op-amp is used to drive the voltage output for the subsequent circuit.

[0068] Optionally, continue to refer to Figure 2As shown, the input end of the second amplifying triode Q2 (the emitter of the second amplifying triode Q2) is connected in series with the output end of the first amplifying triode Q1 (the emitter of the first amplifying triode Q1) through the third resistor R3 and the fourth resistor R4 in sequence, the third resistor R3 is located on the side of the fourth resistor R4 close to the second amplifying triode Q2, the control end of the second amplifying triode Q2 (the base of the second amplifying triode Q2) is connected in series with the output end of the operational amplifier Op-amp in sequence through the second diode D2, the eighth resistor R8, the seventh diode D7 and the sixth diode D6, the second diode D2 is located on the side of the eighth resistor R8 close to the second amplifying triode Q2, the anode of the second diode D2 is close to the second amplifying triode Q2, the anode of the sixth diode D6 is close to the operational amplifier Op-amp, the anode of the seventh diode D7 is close to the sixth diode D6, the anode of the second amplifying triode Q2 is close to the The output end (collector of the second amplifying transistor Q2) is grounded GND, one end of the second parallel resistor is connected between the second diode D2 and the eighth resistor R8, and the other end of the second parallel resistor is grounded GND. The second parallel resistor includes a ninth resistor R9 and a tenth resistor R10 connected in parallel. The ninth resistor R9 and the tenth resistor R10 can play a role in voltage division and current limiting for the second diode D2. By setting the ninth resistor R9, the tenth resistor R10 and the second diode D2, the voltage and current of the control end of the second amplifying transistor Q2 can be set, so as to realize the amplification and switching function of the second amplifying transistor Q2 for the signal in a manner of controlling a large current with a small current; it should be noted that the second parallel resistor may include the ninth resistor R9 and the tenth resistor R10 connected in parallel, or the second parallel resistor may be set to a single resistor (not shown in the figure), which is not specifically limited here.

[0069] In an alternative embodiment, continue to refer to Figure 2As shown, the overcurrent control unit includes an overcurrent switch tube group, the input end of the overcurrent switch tube group is electrically connected to the control end of the first amplifying triode Q1 in the push-pull amplifier circuit, the output end of the overcurrent switch tube group is electrically connected to the control end of the second amplifying triode Q2 in the push-pull amplifier circuit, the overcurrent switch tube group includes a first control triode Q3 and a second control triode Q4, the input end of the first control triode Q3 is electrically connected to the control end of the first amplifying triode Q1, the output end of the first control triode Q3 is electrically connected to the input end of the second control triode Q4, and the output end of the second control triode Q4 is electrically connected to the control end of the second amplifying triode Q4. The overcurrent control unit is electrically connected to the control end of the second amplifying transistor Q2, and further includes a first control diode D01 and a second control diode D02 connected in series with each other, wherein the anode of the first control diode D01 is electrically connected to the output end of the first control transistor Q3, the cathode of the second control diode D02 is electrically connected to the input end of the second control transistor Q4, the anode of the second control diode D02 and the cathode of the first control diode D01 are electrically connected to the output end of the push-pull amplifier circuit, and the first control diode D01 and the second control diode D02 can play the role of isolating voltage and current division.

[0070] In an alternative embodiment, continue to refer to Figure 2 As shown, one end of the overcurrent regulating unit is electrically connected to the control end of the overcurrent switch tube group, and the other end of the overcurrent regulating unit is electrically connected to the output end of the first amplifying triode Q1 and the input end of the second amplifying triode Q2; when the signal current value of the target resolver drive signal output by the push-pull amplifier circuit exceeds the preset current value, the overcurrent regulating unit controls the overcurrent switch tube group to turn on, so that the output current of the first amplifying triode Q1 is reduced, and the output current of the second amplifying triode Q2 is increased; the overcurrent regulating unit includes a first regulating member and a second regulating member, the input end of the first regulating member is electrically connected to the output end of the first amplifying triode Q1, the output end of the first regulating member is electrically connected to the control end of the first control triode Q3, the input end of the second regulating member is electrically connected to the input end of the second amplifying triode Q2, and the output end of the second regulating member is electrically connected to the control end of the second control triode Q4. When the signal current value of the target resolver drive signal exceeds the preset current value, the output voltages of the first regulating member and the second regulating member reach the turn-on voltages of the first control triode Q3 and the second control triode Q4, respectively.

[0071] Optionally, continue to refer to Figure 2As shown, the first adjusting component includes a first adjusting resistor R1, the input end of the first adjusting resistor R1 is electrically connected to the output end of the first amplifying transistor Q1, and the output end of the first adjusting resistor R1 is electrically connected to the control end of the first control transistor Q3; the second adjusting component includes a second adjusting resistor R2, the input end of the second adjusting resistor R2 is electrically connected to the input end of the second amplifying transistor Q2, and the output end of the second adjusting resistor R2 is electrically connected to the control end of the second control transistor Q4. When the signal current value of the target rotary drive signal exceeds the preset current value, the voltage on the first adjusting resistor R1 reaches the turn-on voltage of the first control transistor Q3, and the voltage on the second adjusting resistor R2 reaches the turn-on voltage of the second control transistor Q4.

[0072] Continue to refer to Figure 2 As shown, the first regulating resistor R1 is used to limit the current at the control end of the first control transistor Q3. By changing the resistance value of the first regulating resistor R1, the current flowing through the control end of the first control transistor Q3 can be adjusted, thereby controlling the amplification factor of the first control transistor Q3. The input end of the first control transistor Q3 can shunt the control end of the first amplifying transistor Q1. The current flowing out of the cathode of the first diode D1 is I D1 , the current flows from the anode of the first diode D1 to the cathode of the first diode D1, and the current flowing into the control terminal of the first amplifier transistor Q1 is I Q1b , the current flowing into the input terminal of the first control transistor Q3 is I Q3c , according to Kirchhoff's current law, I D1 =I Q1b +I Q3c Kirchhoff's Current Law (also known as the Node Current Law) was proposed by German physicist GR Kirchhoff (Gustav Robert Kirchhoff, 1824-1887) in 1845. It states that at any node in a circuit, at any time, the sum of the currents flowing into the node is equal to the sum of the currents flowing out of the node.

[0073] Continue to refer to Figure 2As shown, the first amplifying transistor Q1 and the first control transistor Q3 can both be NPN transistors, the second amplifying transistor Q2 and the second control transistor Q4 can both be PNP transistors, the NPN transistor is composed of two N-type semiconductors and one P-type semiconductor, and the PNP transistor is composed of two P-type semiconductors and one N-type semiconductor; it should be emphasized that since the first amplifying transistor Q1 is used as the output of the amplified signal current value when receiving a positive voltage signal, and the first control transistor Q3 is used to shunt the first amplifying transistor Q1, the first amplifying transistor Q1 and the first control transistor Q3 are required to be transistors of the same type. Similarly, the second amplifying transistor Q3 and the second control transistor Q4 are required to be transistors of the same type.

[0074] In an alternative embodiment, continue to refer to Figure 2 As shown, the voltage amplification circuit includes a voltage amplification capacitor C1 and a voltage amplification resistor R5, the voltage amplification capacitor C1 and the voltage amplification resistor R5 are connected in parallel with each other, and the positive electrode of the voltage amplification capacitor C1 is electrically connected to the output end of the signal output unit, the negative electrode of the voltage amplification capacitor C1 is electrically connected to the output end of the push-pull amplifier circuit, one end of the thirteenth resistor R13 is connected to the inverting input end of the operational amplifier Op-amp, the positive electrode of the voltage amplification capacitor C1 is connected to the thirteenth resistor R13 and the inverting input end of the operational amplifier Op-amp, the voltage amplification resistor R5, the voltage amplification capacitor C1 and the operational amplifier Op-amp and the thirteenth resistor R13 are connected. An inverting proportional operational amplifier is formed between the resistors R13, wherein the thirteenth resistor R13 is an input resistor, and the voltage amplification resistor R5 is a feedback resistor. By adjusting the size of the voltage amplification resistor R5, full-band signal amplification can be achieved. The function of the voltage amplification capacitor C1 is to attenuate the high-frequency amplification factor. The higher the frequency, the closer the capacitor is to a short circuit, that is, the high-frequency signal has a low amplification factor through capacitor coupling, and the low-frequency signal has a high amplification factor through resistor coupling. This circuit through the operational amplifier Op-amp and the voltage amplification capacitor C1 can also be called an active low-pass filter, so that the voltage amplification circuit plays a role in enhancing the signal voltage value corresponding to the initial resolver drive signal.

[0075] Continue to refer to Figure 2As shown, the resolver drive protection circuit provided in this embodiment also includes an overvoltage detection unit, the input end of the overvoltage detection unit is electrically connected to the output end of the signal amplification unit, and is used to reduce the signal voltage value of the target resolver drive signal output by the signal amplification unit after the signal voltage value of the target resolver drive signal exceeds the preset voltage value; the overvoltage detection unit includes an overvoltage detection diode D3, the anode of the overvoltage detection diode D3 is electrically connected to the output end of the signal amplification unit, and the cathode of the overvoltage detection diode D3 is connected to the power supply VCC_RDC. The overvoltage detection diode D3 can play a role in conducting and discharging energy. The overvoltage detection diode D3 can clamp the signal voltage value of the target resolver drive signal output by the signal amplification unit at a lower level, thereby playing a role in overvoltage protection for the entire resolver drive protection circuit.

[0076] Optionally, continue to refer to Figure 2 As shown, the signal voltage value of the target resolver drive signal is not greater than 5.5V. Usually, the rated working voltage of the rotary drive is 5V. The overvoltage detection diode D3 can trigger the overvoltage protection when the voltage in the resolver drive circuit is higher than the rated working voltage of 0.5V. It can be understood that when the signal voltage value of the target resolver drive signal gradually increases from 0V to 5.5V, the overvoltage detection diode D3 will not trigger the overvoltage protection. When the signal voltage value of the target resolver drive signal exceeds 5.5V, the overvoltage detection diode D3 triggers the overvoltage protection and starts to conduct to discharge energy until the signal voltage value of the target resolver drive signal is reduced to a level not higher than 5.5V. By setting the overvoltage detection diode D3, the signal voltage value of the target resolver drive signal can be controlled at a relatively stable level.

[0077] In an alternative embodiment, continue to refer to Figure 2 As shown, the signal output unit includes a signal generator (not shown in the figure) and a second-order passive resistor-capacitor filter 1, the signal generator is used to output an initial resolver drive signal, the input end of the second-order passive resistor-capacitor filter is electrically connected to the output end of the signal generator, and the output end of the second-order passive resistor-capacitor filter is electrically connected to the input end of the signal amplification unit.

[0078] Optionally, the signal generator can be the MCU in the car. MCU is a computer system integrated on a single chip, which integrates CPU (Central Processing Unit), memory, counter, USB (Universal Serial Bus) interface, analog-to-digital converter, UART (Universal Asynchronous Receiver Transmitter), PLC (Programmable Logic Controller), DMA (Dynamic mechanical analysis) and other functional modules and interfaces. MCU is mainly responsible for controlling various peripheral circuits and interface circuits of automobiles (including but not limited to new energy vehicles). The performance and reliability of MCU directly affect the overall performance and safety of the automobile.

[0079] The MCU is mainly composed of multiple functional modules, which cooperate with each other to complete various control tasks. The functional modules of the MCU include but are not limited to the MCU timer. The MCU timer is an electronic component mainly used for timing control and has the ability to accurately time. It can trigger specific operations within a set time interval, such as sending data, collecting sensor information, detecting input signals or generating regular output waveforms; in this embodiment, the MCU timer is connected to the input end of the second-order passive resistor-capacitor filter 1, and is used to provide an initial signal RDC_IN to the second-order passive resistor-capacitor filter 1. The initial signal RDC_IN can be a SVPWM (Space Vector Pulse Width Modulation) DC signal. The SVPWM DC signal is a signal generated by the space vector pulse width modulation technology. SVPWM is an advanced pulse width modulation technology specifically used for voltage modulation in AC motor drivers. It achieves precise control of the output voltage by controlling the relative position and length of the voltage vector, thereby improving the efficiency, stability and accuracy of motor control.

[0080] Optionally, continue to refer to Figure 2As shown, the input end of the second-order passive resistor-capacitor filter 1 is connected to the MCU, the output end of the second-order passive resistor-capacitor filter 1 is connected to the input end of the front filter circuit 2, and the output end of the front filter circuit 2 is connected to the inverting input end of the operational amplifier Op-amp; the second-order passive resistor-capacitor filter 1 includes an eleventh resistor R11 and a twelfth resistor R12 connected in series, the side of the eleventh resistor R11 away from the twelfth resistor R12 is connected to the MCU, and the side of the twelfth resistor R12 away from the eleventh resistor R11 is connected to the input end of the front filter circuit 2; the eleventh resistor R11 and the twelfth resistor R12 are connected to the second resistor R11. The first electrode of the second capacitor C2 is connected, the second electrode of the second capacitor C2 is grounded GND, the twelfth resistor R12 and the front filter circuit 2 are connected to the first electrode of the third capacitor C3, the second electrode of the third capacitor C3 is grounded GND, and the eleventh resistor R11, the twelfth resistor R12, the second capacitor C2 and the third capacitor C3 constitute a second-order passive resistor-capacitor circuit (also known as a second-order passive resistor-capacitor filter, a second-order passive RC filter), and the initial signal (SVPWM wave signal) input by the MCU to the second-order passive resistor-capacitor filter 1 can be converted into a sinusoidal wave signal after being processed by the second-order passive resistor-capacitor filter 1.

[0081] Continue to refer to Figure 2 As shown, the front filtering circuit 2 includes a fourth capacitor C4 and a thirteenth resistor R13, the fourth capacitor C4 is connected in series between the twelfth resistor R12 and the thirteenth resistor R13, the thirteenth resistor R13 is connected to the inverting input terminal of the operational amplifier Op-amp on the side away from the fourth capacitor C4, the first electrode of the fifth capacitor C5 is connected between the thirteenth resistor R13 and the inverting input terminal of the operational amplifier Op-amp, the second electrode of the fifth capacitor C5 is grounded GND, the fourth capacitor C4 can filter out the DC voltage in the sinusoidal wave signal and retain the pure AC sinusoidal wave, the thirteenth resistor R13 and the fifth capacitor C5 constitute a low-pass filter, which can further filter out the high-frequency signal at the source end, and the sinusoidal wave signal output by the second-order passive resistor-capacitor filter 1 is converted into an initial resolver drive signal after being processed by the front filtering circuit 2.

[0082] Continue to refer to Figure 2 As shown, the resolver drive protection circuit provided in this embodiment also includes a post-filtering circuit 3, the input end of the post-filtering circuit 3 is electrically connected to the output end of the signal amplifying unit, the output end of the post-filtering circuit 3 is grounded GND, the post-filtering circuit 3 includes a tenth capacitor C10, the first pole of the tenth capacitor C10 is electrically connected to the output end of the signal amplifying unit, the second pole of the tenth capacitor C10 is grounded GND, and the tenth capacitor C10 is used to stabilize the working voltage of the circuit, reduce voltage fluctuations and noise, ensure the stable operation of the circuit, reduce noise and interference in the circuit, improve the quality and accuracy of the signal, and improve the safety and reliability of the system.

[0083] Continue to refer to Figure 2 As shown, the resolver drive protection circuit provided in this embodiment also includes a signal acquisition circuit 4, the input end of the signal acquisition circuit 4 is electrically connected to the positive electrode of the overvoltage detection diode D3, and the input end of the signal acquisition circuit 4 is electrically connected to the resolver (not shown in the figure), and an eighteenth resistor R18 is provided on the signal acquisition circuit 4, one end of the eighteenth resistor R18 is electrically connected to the positive electrode of the overvoltage detection diode D3, and the other end of the eighteenth resistor R18 can output a diagnostic signal RDC_OUT_DIAG, and the diagnostic signal RDC_OUT_DIAG can be used to determine whether the resolver drive protection circuit is working normally; the eighteenth resistor R18 is away from A nineteenth resistor R19 is connected to one side of the overvoltage detection diode D3, and a side of the nineteenth resistor R19 away from the eighteenth resistor R18 is grounded GND. A twentieth resistor R20 is connected to the side of the eighteenth resistor R18 away from the overvoltage detection diode D3, and a side of the twentieth resistor R20 away from the eighteenth resistor R18 is grounded GND. A ninth capacitor C9 is connected to the side of the eighteenth resistor R18 away from the overvoltage detection diode D3, and a side of the ninth capacitor C9 away from the eighteenth resistor R18 is grounded GND. A side of the eighteenth resistor R18 away from the overvoltage detection diode D3 is connected to the cathode of the eighth diode D8, and the anode of the eighth diode D8 is grounded.

[0084] Continue to refer to Figure 2 As shown, the working principle and function of the resolver drive protection circuit provided in this embodiment are as follows:

[0085] (1) Main function: The MCU timer generates an SVPWM signal, which is converted into a sine wave signal after passing through a second-order passive resistor-capacitor filter 1. The sine wave signal is converted into an initial resolver drive signal after passing through a pre-filter circuit 2. The initial resolver drive signal is injected into the inverting input terminal of the operational amplifier Op-amp. The initial resolver drive signal is processed by the operational amplifier Op-amp, the first amplifying transistor Q1, and the second amplifying transistor Q2. The signal current value corresponding to the initial resolver drive signal is amplified. The initial resolver drive signal is processed by the operational amplifier Op-amp, the voltage amplifying resistor R5, and the voltage amplifying capacitor C1. The signal voltage value corresponding to the initial resolver drive signal is Amplification, the initial resolver drive signal after the signal current value and the signal voltage value are amplified is the target resolver drive signal, the target resolver drive signal can be provided to the resolver to make it work, when the signal voltage value and the signal current value of the target resolver drive signal are too large, the circuit will be burned out, so it is necessary to further process the target resolver drive signal, and the processing method is to apply a protection structure (i.e., an overcurrent regulating unit and an overvoltage detection unit) to the circuit, when the protection structure plays the current limiting and voltage limiting protection function, the signal current value of the target resolver drive signal is reduced to a level not higher than the preset signal current value, and the signal voltage value of the target resolver drive signal is reduced to a level not higher than the preset signal voltage value, and finally the reduced target resolver drive signal is provided to the resolver to make it work.

[0086] (2) Current limiting protection function: When the signal current value of the target resolver drive signal is too high, the voltage drop (also called voltage or potential difference) V generated on the fourth resistor R4 R4 Rapidly rises above the voltage V at the control terminal of the first control transistor Q3 Q3b The voltage V at the cathode of the first control diode D01 D01K The sum of the voltages, positive and negative voltages are generated at both ends of the first regulating resistor R1, a negative voltage is generated on the side of the first regulating resistor R1 close to the first control transistor Q3, and a positive voltage is generated on the side of the first regulating resistor R1 close to the first amplifying transistor Q1. The voltage difference between the positive voltage and the negative voltage can be 1V, which is not specifically limited here. A current flows through the first regulating resistor R1 and flows into the control end of the first control transistor Q3. Similarly, a current flows through the second regulating resistor R2 and flows into the control end of the second control transistor Q4. The first control transistor Q3 and the second control transistor Q4 enter the amplifying state. It can be understood that the first control transistor Q3 and the second control transistor Q4 are both turned on, and the current I flowing into the input end of the first control transistor Q3 Q3c From 0 (when I Q3c =0, the first control transistor Q3 and the second control transistor Q4 are both turned off) gradually increase, and the current I at the input end of the first control transistor Q3 Q3cCompared with the current I flowing into the control terminal of the first amplifier transistor Q1 Q1b is the bypass current, I Q3c Can I Q1b To split the flow, according to formula I D1 =I Q1b +I Q3c , when I Q1b When the value of I increases Q3c The value decreases when I Q1b When the value of I decreases Q3c The value of I D1 The value of I remains unchanged. Q3c The value of I Q1b The value of passive gradually decreases according to formula I Q1c =I Q1b ×β, β is the current amplification factor of the first amplifying transistor Q1, which is a constant and represents the current amplification capability of the first amplifying transistor Q1. The value of β is related to the properties of the first amplifying transistor Q1 itself. The value of β is not specifically limited here. When I Q1b When the value of gradually decreases, I Q1c The value of is also gradually reduced, because the signal current of the target resolver drive signal is approximately equal to the current I at the input end of the first amplifier transistor Q1 Q1c , the signal current value of the target resolver drive signal increases with I Q1c The current limiting protection function is achieved by reducing the current and thereby reducing the current. In this embodiment, a first regulating resistor R1 is connected in series to the control end of the first control transistor Q3, and a second regulating resistor R2 is connected in series to the control end of the second control transistor Q4. The resistance value of the first regulating resistor R1 and the resistance value of the second regulating resistor R2 can be adjusted. For example, the resistance value of the first regulating resistor R1 and the resistance value of the second regulating resistor R2 are both 1000Ω. Without changing the resistance values ​​of the fourth resistor R4 and the third resistor R3, the threshold value of the protection current can be adjusted more finely and independently by adjusting the resistance value of the first regulating resistor R1 and the resistance value of the second regulating resistor R2.

[0087] (3) Overvoltage protection function: When the signal acquisition circuit 4 is overvoltage (for example, when the signal voltage value of the target resolver drive signal exceeds 5.5V), the overvoltage detection diode D3 can be turned on to discharge energy. The overvoltage detection diode D3 can clamp the signal voltage value of the target resolver drive signal to a level not exceeding 5.5V, thereby providing overvoltage protection for the entire resolver drive protection circuit; the drive circuit that provides signals to the resolver in the prior art uses a TVS diode to provide overvoltage protection. The TVS diode (also known as a transient voltage suppression diode or transient voltage suppressor) is a high-efficiency protection device for protecting electronic circuits from damage by voltage spikes and surge pulses. The TVS diode is usually installed at the external interface of the drive circuit, which can be understood as being close to the external resolver signal connector, while the TVS diode in this application The overvoltage detection diode D3 can be installed near the driving signal and does not need to be placed near the resolver signal connector. The TVS diode in the prior art only protects the external interface. The diode has an overvoltage protection function only when the voltage in the driving circuit is much higher than the working voltage of the resolver. For example, the diode is installed at the external interface of the driving circuit, and the rated voltage of the resolver is 5V. The voltage in the driving circuit continues to rise. When the voltage rises to 7V or even 9V, the TVS diode will play an overvoltage protection role. The rated voltage of the resolver provided in this embodiment is also 5V. The actual voltage of the circuit is increased by about 0.5V-0.7V compared to the rated voltage. The overvoltage detection diode D3 can trigger the overvoltage protection. Compared with the TVS diode in the prior art, the overvoltage protection function of this embodiment is more sensitive and the triggering time is shorter.

[0088] In summary, this embodiment introduces negative feedback to provide the current sampling resistor voltage signal to the shunt control circuit, and uses Kirchhoff's node current law to increase the shunt current (reduce the base current of the driving transistor) to indirectly reduce the current amplification factor of the driving transistor to achieve the current limiting function; the overvoltage protection function is achieved by connecting a clamping diode (overvoltage detection diode D3) to the power supply to pull down the overvoltage signal.

[0089] Example 2

[0090] This embodiment is an extension solution based on Embodiment 1.

[0091] Figure 3 1 is a circuit diagram of another resolver drive protection circuit provided by the present invention. Figure 2 and Figure 3 As shown, this embodiment provides a resolver drive protection circuit, including a first circuit N and a second circuit P. The structures of the first circuit N and the second circuit P are the same as those of embodiment 1 ( Figure 2) provide a basically identical resolver drive protection circuit structure. To simplify the circuit diagram, the first circuit N and the second circuit P can share the sixteenth resistor R16, the seventeenth resistor R17, the seventh capacitor C7 and the eighth capacitor C8. The input end of the first circuit N and the input end of the second circuit P must be connected to the same group of MCU differential timers. The first circuit N and the second circuit P act simultaneously and are converted into a pair of differential sinusoidal wave signals through the subsequent circuit, thereby forming a resolver drive signal.

[0092] Continue to combine Figure 2 and Figure 3 As shown, the differences between the first circuit N and the second circuit P are as follows:

[0093] (1) The structures of the first operational amplifier Op-amp' in the first circuit N and the second operational amplifier Op-amp" in the second circuit P may be different or the same. Since the role played by the first operational amplifier Op-amp' in the first circuit N is the same as the role played by the second operational amplifier Op-amp" in the second circuit P, whether the structures of the first operational amplifier Op-amp' and the second operational amplifier Op-amp" are the same has no effect on the circuits. Parameters such as the models of the first operational amplifier Op-amp' and the second operational amplifier Op-amp" and whether they are the same are not specifically limited herein.

[0094] (2) The initial signal provided by the MCU timer to the first circuit N is the first initial resolver drive signal RDC_IN_N, and the initial signal provided by the MCU timer to the second circuit P is the second initial resolver drive signal RDC_IN_P. The first initial resolver drive signal RDC_IN_N is different from the second initial resolver drive signal RDC_IN_P.

[0095] It should be noted that: Figure 2 The sixteenth resistor R16 shown is applied to Figure 3 In the first circuit N, Figure 3 The sixteenth resistor is marked as R16N, and the connection position and working principle of the sixteenth resistor R16N in the first circuit N are exactly the same as the connection position and working principle of the sixteenth resistor R16 in the resolver drive protection circuit in Example 1. Figure 2 When the sixteenth resistor R16 shown is applied to the second circuit P, Figure 3 The sixteenth resistor is marked as R16P, and the connection position and working principle of the sixteenth resistor R16N in the second circuit P are exactly the same as the connection position and working principle of the sixteenth resistor R16 in the resolver drive protection circuit in Example 1; similarly, when Figure 2 The overvoltage detection diode D3 is shown to be applied to Figure 3 In the first circuit N, Figure 3 The overvoltage detection diode in the embodiment is marked as D3N. The connection position and working principle of the overvoltage detection diode D3N in the first circuit N are exactly the same as the connection position and working principle of the overvoltage detection diode D3 in the resolver drive protection circuit in Example 1. Figure 2 When the overvoltage detection diode D3 shown is applied to the second circuit P, the reference numeral of the overvoltage detection diode is D3P. The connection position and working principle of the overvoltage detection diode D3P in the second circuit P are exactly the same as the connection position and working principle of the overvoltage detection diode D3 in the resolver drive protection circuit in Example 1. This rule also applies to Figure 2 and Figure 3 All the structures in will not be described here.

[0096] Continue to combine Figure 2 and Figure 3 As shown, the working principle and function of the resolver drive protection circuit provided in this embodiment are as follows:

[0097] (1) Main function: The MCU timer generates two SVPWM signals with a phase difference of 180°. The two SVPWM signals are a pair of differential signals, namely, a first initial resolver drive signal RDC_IN_N and a second initial resolver drive signal RDC_IN_P. In the first circuit N, the first initial resolver drive signal RDC_IN_N is converted into a sine wave signal by a second-order passive RC filter composed of an eleventh resistor R11N, a second capacitor C2N, a twelfth resistor R12N and a third capacitor C3N. The sine wave signal is converted into a first initial resolver drive signal by passing through a fourth capacitor C4N, a thirteenth resistor R13N and a fifth capacitor C5N. The first initial resolver drive signal is injected into the inverting input terminal of the first operational amplifier Op-amp'. The first operational amplifier Op-amp', the first amplifying transistor Q1N and the second amplifying transistor Q2N cooperate with each other to process the first initial resolver drive signal. The signal current value corresponding to the first initial resolver drive signal is amplified. The first initial resolver drive signal is processed by the cooperation between the first operational amplifier Op-amp', the voltage amplifying resistor R5N and the voltage amplifying capacitor C1N, the signal voltage value corresponding to the first initial resolver drive signal is amplified, and the first initial resolver drive signal after the signal current value and the signal voltage value are amplified is the first target resolver drive signal, and the first target resolver drive signal can be provided to the resolver to make it work. When the signal current value and the signal voltage value of the first target resolver drive signal are too large, the circuit will be burned out, so it is necessary to further process the first target resolver drive signal, and the processing method is to apply a protection structure (i.e., an overcurrent regulating unit and an overvoltage detection unit) to the circuit. When the protection structure plays a current limiting and voltage limiting protection function, the signal current value of the first target resolver drive signal is reduced to a level not higher than the preset signal current value, and the signal voltage value of the first target resolver drive signal is reduced to a level not higher than the preset signal voltage value, and the first target resolver drive signal after the reduction is finally provided to the resolver to make it work;Similarly, in the second circuit P, the second target rotary drive signal RDC_IN_P is transformed into a sinusoidal wave signal by a second-order passive RC filter composed of an eleventh resistor R11P, a second capacitor C2P, a twelfth resistor R12P and a third capacitor C3P. The sinusoidal wave signal passes through the fourth capacitor C4P, the thirteenth resistor R13P and the fifth capacitor C5P to obtain a second initial rotary drive signal, and the second initial rotary drive signal is injected into the inverting input terminal of the second operational amplifier Op-amp", and the second initial rotary drive signal is processed by the second operational amplifier Op-amp", the first amplifying transistor Q1P and the second amplifying transistor Q2P. The signal current value corresponding to the second initial rotary drive signal is amplified, and the second operational amplifier Op-amp", the voltage amplifying resistor R5P and the voltage amplifying capacitor C1P cooperate with each other to process the second initial rotary drive signal. The second initial resolver drive signal, the signal voltage value corresponding to the second initial resolver drive signal is amplified, and the second initial resolver drive signal after the signal current value and the signal voltage value are amplified is the second target resolver drive signal, and the second target resolver drive signal can be provided to the resolver to make it work. When the signal current value and the signal voltage value of the second target resolver drive signal are too large, the circuit will be burned out. Therefore, the second target resolver drive signal needs to be further processed. The processing method is to apply a protection structure (i.e., an overcurrent regulating unit and an overvoltage detection unit) to the circuit. When the protection structure plays a current limiting and voltage limiting protection function, the signal current value of the second target resolver drive signal is reduced to a level not higher than the preset signal current value, and the signal voltage value of the second target resolver drive signal is reduced to a level not higher than the preset signal voltage value. Finally, the reduced second target resolver drive signal is provided to the resolver to make it work. ;

[0098] (2) Current limiting protection function: In the first circuit N, when the signal current value of the first target resolver drive signal is too high, the voltage drop (also called voltage or potential difference) V generated on the fourth resistor R4N R4N Rapidly rises above the voltage V at the control terminal of the first control transistor Q3N Q3Nb The voltage V at the cathode of the first control diode D01N D01NK The sum of the voltages, positive and negative voltages are generated at both ends of the first regulating resistor R1N respectively, a negative voltage is generated on the side of the first regulating resistor R1N close to the first control transistor Q3N, and a positive voltage is generated on the side of the first regulating resistor R1N close to the first amplifying transistor Q1N. A current flows through the first regulating resistor R1N and flows into the control end of the first control transistor Q3N. Similarly, a current flows through the second regulating resistor R2N and flows into the control end of the second control transistor Q4N. The first control transistor Q3N and the second control transistor Q4N enter the amplifying state, that is, the first control transistor Q3N and the second control transistor Q4N are both turned on, and the current I flowing into the input end of the first control transistor Q3NQ3Nc From 0 (when I Q3Nc =0, the first control transistor Q3N and the second control transistor Q4N are both turned off) gradually increase, and the current I at the input end of the first control transistor Q3N Q3Nc Compared with the current I flowing into the control terminal of the first amplifier transistor Q1N Q1Nb is the bypass current, I Q3Nc Can I Q1Nb To split the flow, according to formula I D1N =I Q1Nb +I Q3Nc , when I Q1Nb When the value of I increases Q3Nc The value decreases when I Q1Nb When the value of I decreases Q3Nc The value of I D1N The value of I remains unchanged. Q3Nc The value of I Q1Nb The value of passive gradually decreases according to formula I Q1Nc =I Q1Nb ×β N , β N is the current amplification factor of the first amplifier transistor Q1N, which is a constant and represents the current amplification capability of the first amplifier transistor Q1N. N The value of is related to the properties of the first amplifier transistor Q1N itself. N The value of is specifically limited. Q1Nb When the value of gradually decreases, I Q1Nc The value of also gradually decreases, because the signal current value of the first target resolver drive signal is approximately equal to the current I at the input end of the first amplifier transistor Q1N Q1Nc , the signal current value of the first target resolver drive signal increases with I Q1Nc Similarly, in the second circuit P, when the signal current value of the second target resolver drive signal is too high, the voltage drop (also called voltage or potential difference) V generated on the fourth resistor R4P is R4P Rapidly rises above the voltage V at the control terminal of the first control transistor Q3P Q3Pb The voltage V at the cathode of the first control diode D01P D01PKThe sum of the voltages, positive and negative voltages are generated at both ends of the first regulating resistor R1P, a negative voltage is generated on the side of the first regulating resistor R1P close to the first control transistor Q3P, and a positive voltage is generated on the side of the first regulating resistor R1P close to the first amplifying transistor Q1P. A current flows through the first regulating resistor R1P and flows into the control end of the first control transistor Q3P. Similarly, a current flows through the second regulating resistor R2P and flows into the control end of the second control transistor Q4P. The first control transistor Q3P and the second control transistor Q4P enter the amplifying state, that is, the first control transistor Q3P and the second control transistor Q4P are both turned on, and the current I flowing into the input end of the first control transistor Q3P Q3Pc From 0 (when I Q3Pc =0, the first control transistor Q3P and the second control transistor Q4P are both turned off) gradually increase, and the current I at the input end of the first control transistor Q3P Q3Pc Compared with the current I flowing into the control terminal of the first amplifier transistor Q1P Q1Pb is the bypass current, I Q3Pc Can I Q1Pb To split the flow, according to formula I D1P =I Q1Pb +I Q3Pc , when I Q1Pb When the value of I increases Q3Pc The value decreases when I Q1Pb When the value of I decreases Q3Pc The value of I D1P The value of I remains unchanged. Q3Pc The value of I Q1Pb The value of passive gradually decreases according to formula I Q1Pc =I Q1Pb ×β P , β P is the current amplification factor of the first transistor Q1P, which is a constant and represents the current amplification capability of the first transistor Q1P. P The value of is related to the properties of the first amplifier transistor Q1P itself. P The value of is specifically limited. Q1Pb When the value of gradually decreases, I Q1Pc The value of also gradually decreases, because the signal current value of the second target resolver drive signal is approximately equal to the current I at the input end of the first amplifier transistor Q1P Q1Pc , the signal current value of the second target resolver drive signal increases with I Q1Pc The current is reduced as the voltage is reduced, thus playing the role of current limiting protection.

[0099] (3) Overvoltage protection function: In the first circuit N, when the signal acquisition circuit 4 is overvoltage (for example, when the signal voltage value of the first target resolver drive signal exceeds 5.5V), the overvoltage detection diode D3N can be turned on to discharge energy, and the overvoltage detection diode D3N can clamp the signal voltage value of the second target resolver drive signal to a level not exceeding 5.5V, thereby providing overvoltage protection for the entire resolver drive protection circuit; similarly, in the second circuit P, when the signal acquisition circuit 4 is overvoltage (for example, when the voltage value of the second target resolver drive signal exceeds 5.5V), the overvoltage detection diode D3P can be turned on to discharge energy, and the overvoltage detection diode D3P can clamp the signal voltage value of the second target resolver drive signal to a level not exceeding 5.5V, thereby providing overvoltage protection for the entire resolver drive protection circuit.

[0100] It can be seen from the above embodiments that the resolver drive protection circuit provided by the present invention achieves at least the following beneficial effects:

[0101] The resolver drive protection circuit provided by the present invention processes the initial resolver drive signal received from the microcontroller unit to obtain a target resolver drive signal, and then provides the target resolver drive signal to the resolver to make it work. The microcontroller unit and the resolver can both be internal structures of the new energy vehicle. The processing method includes increasing the signal current value and the signal voltage value of the initial resolver drive signal. Compared with the circuit in the prior art, the resolver drive protection circuit adds an overcurrent regulation unit. The overcurrent regulation unit can play a current limiting role to avoid the signal current value of the target resolver drive signal provided to the resolver being too large. By adjusting the overcurrent regulation unit, the signal current value of the target resolver drive signal can be changed. Compared with the prior art, the resolver drive protection circuit can more finely and independently adjust the threshold of the protection current, and the overcurrent protection function is more sensitive and the triggering time is shorter.

[0102] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A resolver drive protection circuit, characterized in that: include: A signal output unit, used for outputting an initial resolver drive signal; A signal amplifying unit, whose input end is connected to the output end of the signal output unit, and is used to amplify the signal voltage value and signal current value corresponding to the received initial resolver drive signal to obtain a target resolver drive signal; An overcurrent regulating unit, used to determine a preset current value according to component parameters of the resolver drive protection circuit; An overcurrent control unit is electrically connected to the signal amplification unit and the overcurrent regulation unit, and is used to reduce the signal current value of the target resolver drive signal output by the signal amplification unit after the signal current value of the target resolver drive signal exceeds the preset current value.

2. The resolver drive protection circuit according to claim 1, characterized in that: The signal amplification unit comprises a push-pull amplifier circuit for amplifying the signal current value corresponding to the initial resolver drive signal; The overcurrent control unit comprises an overcurrent switch tube group; the input end of the overcurrent switch tube group is electrically connected to the control end of the first amplifying triode in the push-pull amplifying circuit, and the output end of the overcurrent switch tube group is electrically connected to the control end of the second amplifying triode in the push-pull amplifying circuit; One end of the overcurrent regulating unit is electrically connected to the control end of the overcurrent switch tube group, and the other end of the overcurrent regulating unit is electrically connected to the output end of the first amplifying transistor and the input end of the second amplifying transistor; When the signal current value of the target resolver drive signal output by the push-pull amplifier circuit exceeds the preset current value, the overcurrent regulation unit controls the overcurrent switch tube group to turn on, so that the output current of the first amplifying transistor is reduced and the output current of the second amplifying transistor is increased.

3. The resolver drive protection circuit according to claim 2, characterized in that: The overcurrent switch tube group includes a first control triode and a second control triode; The input end of the first control transistor is electrically connected to the control end of the first amplifying transistor, the output end of the first control transistor is electrically connected to the input end of the second control transistor, and the output end of the second control transistor is electrically connected to the control end of the second amplifying transistor; The overcurrent regulating unit includes a first regulating member and a second regulating member; The input end of the first adjusting member is electrically connected to the output end of the first amplifying transistor, the output end of the first adjusting member is electrically connected to the control end of the first control transistor, the input end of the second adjusting member is electrically connected to the input end of the second amplifying transistor, and the output end of the second adjusting member is electrically connected to the control end of the second control transistor; When the signal current value of the target resolver drive signal exceeds the preset current value, the output voltages of the first adjustment component and the second adjustment component reach the turn-on voltages of the first control transistor and the second control transistor, respectively.

4. The resolver drive protection circuit according to claim 3, characterized in that: The first adjusting member includes a first adjusting resistor; The input end of the first regulating resistor is electrically connected to the output end of the first amplifying transistor, and the output end of the first regulating resistor is electrically connected to the control end of the first control transistor; The second adjusting member includes a second adjusting resistor; The input end of the second regulating resistor is electrically connected to the input end of the second amplifying transistor, and the output end of the second regulating resistor is electrically connected to the control end of the second control transistor; When the signal current value of the target resolver drive signal exceeds the preset current value, the voltage on the first regulating resistor reaches the turn-on voltage of the first control transistor, and the voltage on the second regulating resistor reaches the turn-on voltage of the second control transistor.

5. The resolver drive protection circuit according to claim 3, characterized in that: The overcurrent control unit also includes a first control diode and a second control diode connected in series; The anode of the first control diode is electrically connected to the output end of the first control transistor; The cathode of the second control diode is electrically connected to the input end of the second control transistor; The anode of the second control diode and the cathode of the first control diode are electrically connected to the output end of the push-pull amplifier circuit.

6. The resolver drive protection circuit according to claim 2, characterized in that: The push-pull amplifier circuit also includes an operational amplifier; The non-inverting input terminal of the operational amplifier is electrically connected to the power supply, the inverting input terminal of the operational amplifier is electrically connected to the output terminal of the signal output unit, and the output terminal of the operational amplifier is electrically connected to the control terminal of the first amplifying transistor and the control terminal of the second amplifying transistor respectively.

7. The resolver drive protection circuit according to claim 2, characterized in that: The signal amplifying unit comprises a voltage amplifying circuit, and the voltage amplifying circuit comprises a voltage amplifying capacitor and a voltage amplifying resistor; The voltage amplifying capacitor and the voltage amplifying resistor are connected in parallel with each other, and the positive electrode of the voltage amplifying capacitor is electrically connected to the output end of the signal output unit, and the negative electrode of the voltage amplifying capacitor is electrically connected to the output end of the push-pull amplifier circuit.

8. The resolver drive protection circuit according to claim 1, characterized in that: The resolver drive protection circuit also includes an overvoltage detection unit; The input end of the overvoltage detection unit is electrically connected to the output end of the signal amplification unit, and is used to reduce the signal voltage value of the target resolver drive signal output by the signal amplification unit after the signal voltage value of the target resolver drive signal exceeds a preset voltage value.

9. The resolver drive protection circuit according to claim 8, characterized in that: The overvoltage detection unit includes an overvoltage detection diode; The anode of the overvoltage detection diode is electrically connected to the output end of the signal amplification unit, and the cathode of the overvoltage detection diode is electrically connected to the power supply.

10. The resolver drive protection circuit according to claim 1, characterized in that: The signal output unit includes a signal generator and a second-order passive resistor-capacitor filter; The signal generator is used to output the initial resolver drive signal; The input end of the second-order passive resistor-capacitor filter is electrically connected to the output end of the signal generator, and the output end of the second-order passive resistor-capacitor filter is electrically connected to the input end of the signal amplification unit.

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