Rotary transducer excitation circuit, rotary transducer interface circuit and driver

Abstract

The application discloses a rotary transformer excitation circuit, a rotary transformer interface circuit and a driver. The rotary transformer excitation circuit comprises an adjustable potentiometer, a conditioning shaping circuit and a current negative feedback amplification circuit. The adjustable potentiometer is used for obtaining an excitation fundamental frequency signal and a resistance adjustment signal from a micro control system to output PWM square wave signals with different amplitudes. The conditioning shaping circuit is connected with the output end of the adjustable potentiometer and is used for generating a standard sine wave signal according to the PWM square wave signal. The current negative feedback amplification circuit is connected with the output end of the conditioning shaping circuit and is used for outputting a rotary transformer excitation signal to the rotary transformer according to the standard sine wave signal. The rotary transformer excitation circuit can adjust the amplitude of the output PWM square wave signal by changing the resistance value of the adjustable potentiometer, and then adjust the amplitude of the rotary transformer excitation signal finally output to the rotary transformer, so that the rotary transformer excitation circuit can adapt to rotary transformers with different transformation ratios and has strong applicability.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electromechanical control, and in particular to a resolver excitation circuit, a resolver interface circuit and a driver. BACKGROUND

[0002] At present, in products such as frequency converters and servo drivers, resolver encoders are used to measure motor rotor positions. Resolver excitation signals are mainly used to provide excitation power for resolvers, and the resolver generates feedback sine and cosine signals according to the target excitation voltage. The interface circuit processes and samples the sine and cosine signals and decodes them to finally obtain the motor rotor position. Due to the difference in the transformation ratio of the resolver on the market, the feedback filter gain needs to be adjusted for different transformation ratios of the resolver, and different resolver excitation signal circuits need to be designed.

[0003] In the interface circuit of the related art, the amplitude and frequency of the resolver excitation signal are not adjustable, and when adapting to resolvers with different transformation ratios, the gain of the feedback filter conditioning circuit needs to be changed in the hardware circuit design, which has poor applicability. SUMMARY

[0004] The present application aims to at least solve one of the technical problems in the prior art, and provides a resolver excitation circuit, a resolver interface circuit and a driver, which can adapt to resolvers with different transformation ratios and have strong applicability.

[0005] In a first aspect, the present application provides a resolver excitation circuit, comprising an adjustable potentiometer, a conditioning shaping circuit and a current negative feedback amplification circuit, wherein:

[0006] The adjustable potentiometer is used to obtain an excitation fundamental frequency signal and a resistance adjustment signal from a micro-control system to output PWM square wave signals with different amplitudes;

[0007] The conditioning shaping circuit is connected to the output end of the adjustable potentiometer and is used to generate a standard sine wave signal according to the PWM square wave signal;

[0008] The current negative feedback amplification circuit is connected to the output end of the conditioning shaping circuit and is used to output a resolver excitation signal to a resolver according to the standard sine wave signal.

[0009] The rotary transformer excitation circuit provided by the embodiment of the present application has at least the following beneficial effects: the rotary transformer excitation circuit is provided with an adjustable potentiometer and receives a resistance adjustment signal of a micro-control system to change the resistance of the adjustable potentiometer, so that the amplitude of the output PWM square wave signal can be adjusted, and the amplitude of the rotary transformer excitation signal finally output to the rotary transformer is adjusted, so that the rotary transformer excitation circuit can adapt to rotary transformers with different transformation ratios; the PWM square wave signal is shaped into a standard sine wave signal by the shaping circuit, so that the anti-interference capability of the output signal can be improved; and the current negative feedback amplification circuit is provided to increase the output driving capability of the sine wave signal, so that the applicability is stronger and the use requirements of different application scenarios can be met.

[0010] The rotary transformer excitation circuit provided by some embodiments of the present application, the shaping circuit comprises a first-order integration circuit for shaping the PWM square wave signal into a triangular wave signal and an integral filter circuit for shaping the triangular wave signal into the standard sine wave signal.

[0011] The rotary transformer excitation circuit provided by some embodiments of the present application, the integral filter circuit comprises an RC integral filter circuit, a voltage follower and a second-order integral filter circuit connected in sequence.

[0012] The rotary transformer excitation circuit provided by some embodiments of the present application, the first-order integral circuit comprises a first operational amplifier and a first capacitor, the inverting terminal of the first operational amplifier is connected to the PWM square wave signal and connected to the output terminal of the first operational amplifier through the first capacitor, and the non-inverting terminal of the first operational amplifier is connected to a first reference voltage.

[0013] The rotary transformer excitation circuit provided by some embodiments of the present application, the RC integral filter circuit comprises a first resistor and a second capacitor, the voltage follower comprises a second operational amplifier, the triangular wave signal is connected to the non-inverting terminal of the second operational amplifier through the first resistor, the non-inverting terminal of the second operational amplifier is grounded through the second capacitor, and the inverting terminal of the second operational amplifier is connected to the output terminal of the second operational amplifier.

[0014] The rotary transformer excitation circuit provided by some embodiments of the present application, the second-order integral filter circuit comprises a second resistor, a third capacitor, a fourth capacitor and a third operational amplifier, the output terminal of the second operational amplifier is connected to the non-inverting terminal of the third operational amplifier through the second resistor and connected to the output terminal of the third operational amplifier through the third capacitor, the non-inverting terminal of the third operational amplifier is grounded through the fourth capacitor, and the inverting terminal of the third operational amplifier is connected to the output terminal of the third operational amplifier.

[0015] According to some embodiments of the present application, the current negative feedback amplification circuit of the rotary transformer excitation circuit comprises a fourth operational amplifier, a first transistor, a second transistor, a third resistor and a fourth resistor. The inverting terminal of the fourth operational amplifier is connected to the standard sine wave signal, the non-inverting terminal of the fourth operational amplifier is grounded, the output terminal of the fourth operational amplifier is connected to the control pin of the first transistor, the control pin of the second transistor and one end of the third resistor respectively, one of the switch pins of the first transistor is connected to the positive pole of the DC power supply, one of the switch pins of the second transistor is connected to the negative pole of the DC power supply, the other switch pin of the first transistor, the other switch pin of the second transistor and the other end of the third resistor are connected together as the output terminal of the current negative feedback amplification circuit and are connected to the inverting terminal of the fourth operational amplifier through the fourth resistor.

[0016] In a second aspect, the present application provides a rotary transformer interface circuit, comprising the rotary transformer excitation circuit of the first aspect, a micro-control system, a feedback conditioning circuit and an ADC module.

[0017] The micro-control system is configured to output the excitation fundamental frequency signal and the resistance adjustment signal.

[0018] The feedback conditioning circuit is configured to condition the sine / cosine raw signal output by the rotary transformer into a target sine / cosine signal. The sine / cosine raw signal comprises two differential signals. The feedback conditioning circuit comprises two differential signal receiving terminals, an enable control terminal, a first MOS transistor and a second MOS transistor. One of the switch pins of the first MOS transistor and one of the switch pins of the second MOS transistor are connected to the two differential signal receiving terminals respectively. The other switch pin of the first MOS transistor and the other switch pin of the second MOS transistor are grounded. The control pins of the first MOS transistor and the second MOS transistor are connected to the enable control terminal.

[0019] The ADC module is configured to digitize the target sine / cosine signal and feed it back to the micro-control system.

[0020] According to the rotary transformer interface circuit provided by the embodiment of the present application, the rotary transformer excitation circuit is provided with an adjustable potentiometer and receives a resistance adjustment signal of the micro-control system to change the resistance of the adjustable potentiometer, so that the amplitude of the output PWM square wave signal can be adjusted, and the amplitude of the rotary transformer excitation signal finally output to the rotary transformer is adjusted, so that the rotary transformer excitation circuit can adapt to rotary transformers with different transformation ratios; the PWM square wave signal is shaped into a standard sine wave signal by the shaping circuit, so that the anti-interference capability of the output signal is improved; the current negative feedback amplification circuit is provided to increase the output driving capability of the sine wave signal, so that the applicability is stronger, and the use requirements of different application scenarios can be met; in addition, when the feedback shaping circuit is not externally connected with the rotary transformer, the first MOS tube and the second MOS tube can be controlled to be turned on by the enable control end, so that the two differential signal receiving ends can be grounded through the first MOS tube and the second MOS tube respectively, and the anti-interference capability of the rotary transformer interface circuit is improved.

[0021] According to the rotary transformer interface circuit provided by some embodiments of the present application, the feedback shaping circuit comprises a first differential amplification circuit and an inverting amplification circuit connected in sequence.

[0022] According to the rotary transformer interface circuit provided by some embodiments of the present application, the feedback shaping circuit further comprises a hysteresis comparator, which is used to detect the zero-crossing point according to the target sine and cosine signals and output to the micro-control system.

[0023] In a third aspect, an embodiment of the present application provides a driver comprising the rotary transformer interface circuit according to the second aspect.

[0024] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and achieved by the structures particularly pointed out in the description, claims and drawings. BRIEF DESCRIPTION OF DRAWINGS

[0025] The accompanying drawings are included to provide a further understanding of the technical solutions of the present application, and constitute a part of the specification, and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation on the technical solutions of the present application.

[0026] The present application will be further described below in combination with the drawings and embodiments;

[0027] Figure 1 is a structural schematic diagram of the rotary transformer interface circuit provided by the embodiment of the present application;

[0028] Figure 2 is a principle block diagram of the rotary transformer excitation circuit provided by the embodiment of the present application;

[0029] Figure 3 is a circuit schematic diagram of a rotary transformer excitation circuit provided by an embodiment of the application.

[0030] Figure 4 is a circuit schematic diagram of a feedback conditioning circuit provided by an embodiment of the application. DETAILED DESCRIPTION

[0031] This part will describe the specific embodiments of the application in detail, and the preferred embodiments of the application are shown in the accompanying drawings, which serve to supplement the description in the text part of the specification and enable people to intuitively and visually understand each technical feature and the overall technical scheme of the application, but cannot be understood as a limitation on the protection scope of the application.

[0032] In the description of the application, if the first, second, etc. are described for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features or the sequence of indicated technical features.

[0033] In the description of the application, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be understood in a broad sense, and the person skilled in the art can reasonably determine the specific meaning of the above words in the application in combination with the specific content of the technical scheme.

[0034] The embodiments of the application provide a rotary transformer excitation circuit 200, a rotary transformer interface circuit 900 and a driver, which can adapt to rotary transformers 500 with different transformation ratios and have strong applicability.

[0035] The embodiments of the application will be further described below with reference to the accompanying drawings.

[0036] Referring to Figure 1 , Figure 1 is a structural schematic diagram of a rotary transformer interface circuit 900 provided by an embodiment of the application. The rotary transformer interface circuit 900 comprises a micro-control system 100, a rotary transformer excitation circuit 200, a feedback conditioning circuit 300 and an ADC module 400. The micro-control system 100 outputs an excitation base frequency signal, which is modulated into a rotary transformer excitation signal by the rotary transformer excitation circuit 200. After receiving the excitation rotary transformer excitation signal, the rotary transformer 500 generates a sine and cosine original signal, which is conditioned into a target sine and cosine signal by the feedback conditioning circuit 300. Finally, after being digitized by the high-precision ADC module 400, the signal is input to the micro-control system 100 for soft decoding, and finally the motor rotor position is obtained.

[0037] Referring to Figure 2 and Figure 3 , Figure 2 is a principle block diagram of a rotary transformer excitation circuit 200 provided by an embodiment of the application, Figure 3is a circuit schematic diagram of a rotary transformer excitation circuit 200 provided by an embodiment of the present application. The first aspect embodiment of the present application provides a rotary transformer excitation circuit 200, comprising an adjustable potentiometer 210, a conditioning shaping circuit 220 and a current negative feedback amplification circuit 230, wherein:

[0038] The adjustable potentiometer 210 is used to obtain an excitation fundamental frequency signal and a resistance adjustment signal from the micro-control system 100, so as to output a PWM square wave signal with different amplitudes.

[0039] The conditioning shaping circuit 220 is connected with the output end of the adjustable potentiometer 210, and is used to generate a standard sine wave signal according to the PWM square wave signal.

[0040] The current negative feedback amplification circuit 230 is connected with the output end of the conditioning shaping circuit 220, and is used to output a rotary transformer excitation signal to the rotary transformer 500 according to the standard sine wave signal.

[0041] According to the rotary transformer excitation circuit 200 provided by the embodiment of the present application, the rotary transformer excitation circuit 200 is provided with the adjustable potentiometer 210 and receives the resistance adjustment signal of the micro-control system 100, so as to change the resistance value of the adjustable potentiometer 210, thereby the amplitude of the output PWM square wave signal can be adjusted, and then the amplitude of the final output rotary transformer excitation signal to the rotary transformer 500 is adjusted, so that the rotary transformer excitation circuit 200 can adapt to rotary transformers 500 with different transformer ratios; the conditioning shaping circuit 220 is further arranged to condition the PWM square wave signal into a standard sine wave signal, which can improve the anti-interference ability of the output signal; and the current negative feedback amplification circuit 230 is further arranged to increase the output driving ability of the sine wave signal, which has strong applicability and can meet the use requirements of different application scenarios.

[0042] Specifically, referring to Figure 3 The adjustable potentiometer 210 is connected with the micro-control system 100 through the port MFB_AX0RES_REF, so as to obtain the excitation fundamental frequency signal; and is further connected with the micro-control system 100 through the DSP_SDAA port or the DSP_SCLA port, so as to obtain the resistance adjustment signal. In addition, it can be seen that the VDD pin of the adjustable potentiometer 210 is connected to the direct current power supply 3V3, the VSS pin is grounded, and the VDD pin is further connected to the VSS pin through the fifth capacitor C5. The B pin of the adjustable potentiometer 210 serves as an output end to output the PWM square wave signal.

[0043] Referring to Figure 3The conditioning shaping circuit 220 of the rotary transformer excitation circuit 200 according to some embodiments of the present application comprises a first-order integration circuit 221 for shaping and conditioning a PWM square wave signal into a triangular wave signal, and an integral filter circuit for shaping and conditioning the triangular wave signal into a standard sinusoidal wave signal. Further, the integral filter circuit comprises an RC integral filter circuit 222, a voltage follower 223 and a second-order integral filter circuit 224 connected in sequence.

[0044] It can be understood that the conditioning shaping circuit 220 is designed as a multi-stage integral filter conditioning circuit, which can obtain a standard sinusoidal excitation signal and improve the anti-interference ability of the output signal.

[0045] With reference to Figure 3 The first-order integration circuit 221 of the rotary transformer excitation circuit 200 according to some embodiments of the present application comprises a first operational amplifier U1A and a first capacitor C1. The inverting terminal of the first operational amplifier U1A is connected to the PWM square wave signal and connected to the output terminal of the first operational amplifier U1A through the first capacitor C1. The non-inverting terminal of the first operational amplifier U1A is connected to a first reference voltage.

[0046] Specifically, with reference to Figure 3 The first-order integration circuit 221 further comprises a fifth resistor R5, a sixth resistor R6, a seventh resistor R7 and a sixth capacitor C6. The output terminal of the adjustable potentiometer 210 is connected to one end of the fifth resistor R5. The other end of the fifth resistor R5 is connected to the inverting terminal of the first operational amplifier U1A. The sixth resistor R6 and the seventh resistor R7 are connected in series between the DC power supply 3V3 and the ground terminal. The connection point of the sixth resistor R6 and the seventh resistor R7 is connected to the non-inverting terminal of the first operational amplifier U1A to provide a first reference voltage to the non-inverting terminal of the first operational amplifier U1A. The non-inverting terminal of the first operational amplifier U1A is further connected to one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

[0047] In addition, it can also be seen that the output terminal of the first operational amplifier U1A serves as the output terminal of the first-order integration circuit 221 for outputting a triangular wave signal to the RC integral filter circuit 222.

[0048] With reference to Figure 3 The RC integral filter circuit 222 of the rotary transformer excitation circuit 200 according to some embodiments of the present application comprises a first resistor R1 and a second capacitor C2. The voltage follower 223 comprises a second operational amplifier U2A. The triangular wave signal is connected to the non-inverting terminal of the second operational amplifier U2A through the first resistor R1. The non-inverting terminal of the second operational amplifier U2A is grounded through the second capacitor C2. The inverting terminal of the second operational amplifier U2A is connected to the output terminal of the second operational amplifier U2A.

[0049] It can also be seen that the conditioning shaping circuit 220 further comprises a seventh capacitor C7 and an eighth resistor R8, the output end of the first-order integration circuit 221 is connected to one end of the seventh capacitor C7, the other end of the seventh capacitor C7 is connected to one end of the eighth resistor R8, the other end of the eighth resistor R8 is grounded, and the connection point of the seventh capacitor C7 and the eighth resistor R8 is further connected to one end of the first resistor R1, so as to input the triangular wave signal to the non-inverting terminal of the second operational amplifier U2A through the first resistor R1.

[0050] It should be noted that the triangular wave signal output by the output end of the first-order integration circuit 221 is input to the non-inverting terminal of the voltage follower 223 through the RC integration filter circuit 222, and the triangular wave signal is conditioned and shaped into a sinusoidal wave signal. It can be understood that the output end of the second operational amplifier U2A outputs the sinusoidal wave signal.

[0051] Continuing to refer to Figure 3 According to some embodiments of the present application, the rotary transformer excitation circuit 200 further comprises a second-order integration filter circuit 224, which comprises a second resistor R2, a third capacitor C3, a fourth capacitor C4, and a third operational amplifier U3A. The output end of the second operational amplifier U2A is connected to the non-inverting terminal of the third operational amplifier U3A through the second resistor R2 and to the output end of the third operational amplifier U3A through the third capacitor C3. The non-inverting terminal of the third operational amplifier U3A is grounded through the fourth capacitor C4, and the inverting terminal of the third operational amplifier U3A is connected to the output end of the third operational amplifier U3A.

[0052] It can also be seen that the second-order integration filter circuit 224 further comprises a ninth resistor R9, and the output end of the second operational amplifier U2A is connected to one end of the ninth resistor R9. The other end of the ninth resistor R9 is connected to the non-inverting terminal of the third operational amplifier U3A through the second resistor R2 and to the output end of the third operational amplifier U3A through the third capacitor C3.

[0053] It should be noted that the second-order integration filter circuit 224 composed of the third operational amplifier U3A and its peripheral circuit conditions and shapes the signal of the previous stage, thereby generating a standard sinusoidal wave signal. The output end of the third operational amplifier U3A serves as the output end of the second-order integration filter circuit 224, and outputs the standard sinusoidal wave signal to the current negative feedback amplification circuit 230.

[0054] Continuing to refer to Figure 3The current negative feedback amplification circuit 230 comprises the fourth operational amplifier U4A, the first transistor Q1, the second transistor Q2, the third resistor R3 and the fourth resistor R4. The inverting terminal of the fourth operational amplifier U4A is connected to the standard sine wave signal, the non-inverting terminal of the fourth operational amplifier U4A is grounded, and the output terminal of the fourth operational amplifier U4A is connected to the control pin of the first transistor Q1, the control pin of the second transistor Q2 and one end of the third resistor R3 respectively. One of the switching pins of the first transistor Q1 is connected to the positive pole of the direct current power supply, one of the switching pins of the second transistor Q2 is connected to the negative pole of the direct current power supply, and the other switching pin of the first transistor Q1, the other switching pin of the second transistor Q2 and the other end of the third resistor R3 are connected together as the output terminal of the current negative feedback amplification circuit 230 and connected to the inverting terminal of the fourth operational amplifier U4A through the fourth resistor R4.

[0055] Specifically, the current negative feedback amplification circuit 230 further comprises the tenth resistor R10, the eleventh resistor R11, the twelfth resistor R12, the eighth capacitor C8, the ninth capacitor C9 and the first fuse F1. The output terminal of the third operational amplifier U3A is connected to one end of the tenth resistor R10, and the other end of the tenth resistor R10 is connected to the inverting terminal of the fourth operational amplifier U4A. The first transistor Q1 is an NPN type transistor, the second transistor Q2 is a PNP type transistor, the output terminal of the fourth operational amplifier U4A is connected to the base of the first transistor Q1, the base of the second transistor Q2 and one end of the third resistor R3 respectively, the other end of the third resistor R3 is connected to the emitter of the first transistor Q1, the emitter of the second transistor Q2 and one end of the first fuse F1, the other end of the first fuse F1 is connected to the inverting terminal of the fourth operational amplifier U4A through the fourth resistor, and the other end of the first fuse F1 is also the output terminal of the current negative feedback amplification circuit 230, that is Figure 3 The other end of the first fuse F1 is also the output terminal of the current negative feedback amplification circuit 230, that is, the port MFB_AX0RES_EXCp in the current negative feedback amplification circuit 230, so as to output the rotary transformer excitation signal to the rotary transformer 500. One end of the eleventh resistor R11 is connected to the positive pole of the direct current power supply +15V, the other end of the eleventh resistor R11 is grounded through the eighth capacitor C8, and the connection point of the eleventh resistor R11 and the eighth capacitor C8 is further connected to the collector of the first transistor Q1. One end of the twelfth resistor R12 is connected to the negative pole of the direct current power supply -15V, the other end of the twelfth resistor R12 is grounded through the ninth capacitor C9, and the connection point of the twelfth resistor R12 and the ninth capacitor C9 is further connected to the collector of the second transistor Q2.

[0056] In Figure 3The port MFB_AX0RES_REF receives a PWM excitation fundamental frequency signal generated by the micro-control system 100, and the default fundamental frequency is 8 kHz. The fundamental frequency of the PWM excitation fundamental frequency signal can be adjusted and set according to the load rotary transformer 500. The adjustable potentiometer 210 is an electronic adjustable resistance potentiometer, and the resistance adjustment range is 0K to 50K. The micro-control system 100 outputs a resistance adjustment signal to the port DSP_SDAA or the port DSP_SCLA through an I2C bus, so as to set the resistance of the electronic adjustable resistance potentiometer. The first operational amplifier U1A and the peripheral circuit thereof constitute a first-order integral circuit 221, which shapes and conditions the PWM square wave signal output by the adjustable potentiometer 210 into a triangular wave signal. The triangular wave signal output by the first operational amplifier U1A passes through an RC integral filter circuit 222 and is input to the non-inverting terminal of the voltage follower 223. The triangular wave signal is shaped and conditioned into a sinusoidal signal. The third operational amplifier U3A and the peripheral circuit thereof constitute a second-order integral filter circuit 224, which conditions and shapes the signal of the previous stage to generate a standard sinusoidal signal. The fourth operational amplifier U4A, the first transistor Q1, the second transistor Q2 and the peripheral circuit thereof constitute a current negative feedback amplification circuit 230, which increases the driving capacity of the sinusoidal signal output. The port MFB_AX0RES_EXCp is an output unit of the rotary transformer excitation circuit 200, and outputs a rotary transformer excitation signal with a maximum driving current of 55 mA. The amplitude peak-to-peak value of the rotary transformer excitation signal can be adjusted by the adjustable potentiometer 210, and the peak-to-peak value VPP output is adjustable in the range of 6V to 22V. The rotary transformer 500 can adapt to the transformer ratio range of 0.45 to 0.8.

[0057] In addition, with reference to Figure 1 and Figure 4 , the second aspect embodiment of the present application provides a rotary transformer interface circuit 900, which comprises the rotary transformer excitation circuit 200 and the micro-control system 100, the feedback conditioning circuit 300 and the ADC module 400 of the first aspect embodiment.

[0058] The micro-control system 100 is used for outputting an excitation fundamental frequency signal and a resistance adjustment signal.

[0059] With reference to Figure 4 , Figure 4is a circuit schematic diagram of the feedback conditioning circuit 300 provided by an embodiment of the present application. The feedback conditioning circuit 300 is used for conditioning the positive and negative sine original signals output by the resolver 500 into target positive and negative sine signals, the positive and negative sine original signals including two differential signals, and the feedback conditioning circuit 300 includes two differential signal receiving ends, an enable control end, a first MOS tube and a second MOS tube, the two differential signal receiving ends are respectively connected to one switch pin of the first MOS tube and one switch pin of the second MOS tube, the other switch pin of the first MOS tube and the other switch pin of the second MOS tube are grounded, and the enable control end is connected to the control pins of the first MOS tube and the second MOS tube.

[0060] The ADC module 400 is used for feeding back the target positive and negative sine signals to the micro-control system 100 after digitization.

[0061] Specifically, the two differential signal receiving ends are port MFB_AX0RES_Sp and port MFB_AX0RES_Sn. It should also be noted that the positive and negative sine original signals output by the resolver 500 include a sine original feedback signal and a cosine original feedback signal, and both the sine original feedback signal and the cosine original feedback signal include two differential signals, so Figure 4 The feedback conditioning circuit 300 shown can be used to process the two differential signals of the sine original feedback signal, and can also be used to process the two differential signals of the cosine original feedback signal. It can be understood that the resolver interface circuit 900 can include two circuit structures same as the feedback conditioning circuit 300 shown Figure 4 The feedback conditioning circuit 300 shown can be used to process the two differential signals of the sine original feedback signal, and can also be used to process the two differential signals of the cosine original feedback signal. It can be understood that the resolver interface circuit 900 can include two circuit structures same as the feedback conditioning circuit 300 shown

[0062] Referring to Figure 4 , the feedback conditioning circuit 300 further includes a thirteenth resistor R13 and a fourteenth resistor R14, the enable control end is port RES_SHORT_SIN, the enable control end RES_SHORT_SIN is connected to one end of the thirteenth resistor R13 and one end of the fourteenth resistor R14, the other end of the thirteenth resistor R13 is connected to the gate of the first MOS tube Q3, the other end of the fourteenth resistor R14 is connected to the gate of the second MOS tube, the port MFB_AX0RES_Sp in the two differential signal receiving ends is connected to the drain of the first MOS tube Q3, the source of the first MOS tube Q3 is grounded, and the port MFB_AX0RES_Sn in the two differential signal receiving ends is connected to the drain of the second MOS tube, and the source of the second MOS tube is grounded.

[0063] According to the rotary transformer interface circuit 900 provided by the embodiment of the present application, the rotary transformer excitation circuit 200 is provided with the adjustable potentiometer 210 and receives the resistance adjustment signal of the micro-control system 100 to change the resistance of the adjustable potentiometer 210, so that the amplitude of the output PWM square wave signal can be adjusted, and then the amplitude of the rotary transformer excitation signal finally output to the rotary transformer 500 is adjusted, so that the rotary transformer excitation circuit 200 can adapt to rotary transformers 500 with different transformation ratios; the conditioning shaping circuit 220 is further provided to condition the PWM square wave signal into a standard sine wave signal, so that the anti-interference ability of the output signal can be improved; and the current negative feedback amplification circuit 230 is further provided to increase the output driving ability of the sine wave signal, so that the applicability is stronger, and the use requirements of different application scenarios can be met; in addition, when the feedback conditioning circuit 300 is not externally connected with the rotary transformer 500, the first MOS tube and the second MOS tube can be controlled to be turned on through the enable control end, so that the two differential signal receiving ends can be grounded through the first MOS tube and the second MOS tube respectively, thereby improving the anti-interference ability of the rotary transformer interface circuit 900.

[0064] With reference to Figure 4 According to the rotary transformer interface circuit 900 provided by some embodiments of the present application, the feedback conditioning circuit 300 comprises the first-order differential amplification circuit 310 and the inverting amplification circuit 320 connected in sequence.

[0065] Specifically, the first-order differential amplification circuit 310 comprises a fifteenth resistor R15, a sixteenth resistor R16, a seventeenth resistor R17, an eighteenth resistor R18, a nineteenth resistor R19, a twentieth resistor R20, a twenty-first resistor R21, a twenty-second resistor R22, a tenth capacitor C10, an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, and a fifth operational amplifier U5A. Among them: the ports MFB_AX0RES_Sp in the two differential signal receiving ends are respectively connected to one end of the fifteenth resistor R15 and one end of the sixteenth resistor R16, the other end of the fifteenth resistor R15 is grounded, the other end of the sixteenth resistor R16 is respectively connected to one end of the seventeenth resistor R17, one end of the eighteenth resistor R18, and one end of the tenth capacitor C10, the other end of the tenth capacitor C10 is grounded, the other end of the seventeenth resistor R17 is respectively connected to the inverting terminal of the fifth operational amplifier U5A and one end of the eleventh capacitor C11, and the other end of the eleventh capacitor C11 and the other end of the eighteenth resistor R18 are both connected to the output terminal of the fifth operational amplifier U5A; the ports MFB_AX0RES_Sn in the two differential signal receiving ends are respectively connected to one end of the nineteenth resistor R19 and one end of the twentieth resistor R20, the other end of the nineteenth resistor R19 is connected to the positive electrode +15V of the direct current power supply, the other end of the twentieth resistor R20 is respectively connected to one end of the twenty-first resistor R21, one end of the twenty-second resistor R22, and one end of the twelfth capacitor C12, the other end of the twenty-first resistor R21 and the other end of the twelfth capacitor C12 are both grounded, and the other end of the twenty-second resistor R22 is respectively connected to the non-inverting terminal of the fifth operational amplifier U5A and one end of the thirteenth capacitor C13, the other end of the thirteenth capacitor C13 is grounded.

[0066] The inverting amplification circuit 320 comprises a twenty-third resistor R23, a twenty-fourth resistor R24, a twenty-fifth resistor R25, and a sixth operational amplifier U6A, the output terminal of the fifth operational amplifier U5A is connected to one end of the twenty-third resistor R23, the other end of the twenty-third resistor R23 is respectively connected to one end of the twenty-fourth resistor R24 and the inverting terminal of the sixth operational amplifier U6A, the other end of the twenty-fourth resistor R24 is connected to the output terminal of the sixth operational amplifier U6A, one end of the twenty-fifth resistor R25 is connected to the non-inverting terminal of the sixth operational amplifier U6A, the other end of the twenty-fifth resistor R25 is grounded, and the output terminal of the sixth operational amplifier U6A is the output terminal of the inverting amplification circuit 320, that is, the port MFB_AX0SIN, used for outputting the target sine signal to the ADC module 400.

[0067] With reference to Figure 4 According to some embodiments of the present application, the spin interface circuit 900 further comprises a hysteresis comparator 330, which is used for detecting the zero-crossing point according to the target sine signal and outputting to the micro-control system 100.

[0068] Specifically, the hysteresis comparator 330 includes a twenty-sixth resistor R26, a twenty-seventh resistor R27, a twenty-eighth resistor R28, a twenty-ninth resistor R29, a fourteenth capacitor C14 and a seventh operational amplifier U7A, an output terminal of the sixth operational amplifier U6A is connected to one end of the twenty-sixth resistor R26, the other end of the twenty-sixth resistor R26 is connected to a non-inverting terminal of the seventh operational amplifier U7A and one end of the twenty-seventh resistor R27 respectively, one end of the twenty-eighth resistor R28 is grounded, the other end of the twenty-eighth resistor R28 is connected to one end of the fourteenth capacitor C14 and an inverting terminal of the seventh operational amplifier U7A respectively, the other end of the fourteenth capacitor C14 is grounded, the other end of the twenty-seventh resistor R27 is connected to an output terminal of the seventh operational amplifier U7A and one end of the twenty-ninth resistor R29 respectively, the other end of the twenty-ninth resistor R29 is connected to a positive electrode of a direct current power supply 3V3, and the output terminal of the seventh operational amplifier U7A also serves as an output terminal of the hysteresis comparator 330, that is, a port MFB_AX0QUAD_SIN, used for outputting a zero-crossing point of a target sine and cosine signal to the micro control system 100.

[0069] In Figure 1 In the resolver interface circuit 900 provided, the sine and cosine original signals fed back by the resolver 500 pass through the feedback conditioning circuit 300, and are input to the high-precision ADC module 400 and the micro control system 100 for soft decoding; the enable control terminal RES_SHORT_SIN controls the feedback conditioning circuit 300, the H level turns off the entire feedback conditioning circuit 300, and the L level enables the feedback conditioning circuit 300. When no external resolver 500 is connected, the enable control terminal RES_SHORT_SIN is not enabled, the feedback conditioning circuit 300 is turned off, and the anti-interference ability of the entire circuit system is improved; the port MFB_AX0RES_Sp and the port MFB_AX0RES_Sn receive the sine original feedback signal or the cosine original feedback signal fed back by the resolver 500, pass through the first-order differential amplification circuit 310 with a gain of 3.25 times and a cutoff frequency of 28 kHz, and then pass through the inverting amplification circuit 320 with a gain of 1, and are input to the high-precision ADC module 400 for analog-digital conversion, and finally output to the micro control system 100; the port MFB_AX0QUAD_SIN outputs the zero-crossing point of the target sine and cosine signal, and the zero-crossing point of the target sine and cosine signal is generated by the hysteresis comparator 330.

[0070] In a third aspect, the embodiments of the present application provide a driver including the resolver interface circuit 900 of the second aspect.

[0071] According to the driver provided by the embodiment of the present application, the resolver excitation circuit 200 in the resolver interface circuit 900 is provided with the adjustable potentiometer 210 and receives the resistance adjustment signal of the micro-control system 100 to change the resistance of the adjustable potentiometer 210, so as to adjust the amplitude of the output PWM square wave signal, and then adjust the amplitude of the resolver excitation signal finally output to the resolver 500, so that the resolver excitation circuit 200 can adapt to the resolver 500 with different transformation ratios; the shaping circuit 220 is further arranged to shape the PWM square wave signal into a standard sine wave signal, so as to improve the anti-interference ability of the output signal; the current negative feedback amplification circuit 230 is further arranged to increase the output driving ability of the sine wave signal, so as to have strong applicability and meet the use requirements of different application scenarios; in addition, when the feedback shaping circuit 300 is not externally connected with the resolver 500, the first MOS tube and the second MOS tube can be controlled to be turned on through the enable control end, so that the two differential signal receiving ends can be grounded through the first MOS tube and the second MOS tube respectively, thereby improving the anti-interference ability of the resolver interface circuit 900.

[0072] The above describes the embodiments of the present application in detail in combination with the drawings, but the present application is not limited to the above embodiments, and various changes can be made within the knowledge range of ordinary skilled in the art without departing from the purpose of the present application.

Claims

1. A resolver excitation circuit, characterized in that, include An adjustable potentiometer is used to acquire the excitation base frequency signal and resistance adjustment signal from the microcontroller system to output PWM square wave signals of different amplitudes; A conditioning and shaping circuit is connected to the output terminal of the adjustable potentiometer and is used to generate a standard sine wave signal based on the PWM square wave signal. A current negative feedback amplifier circuit is connected to the output terminal of the conditioning and shaping circuit, and is used to output a resolver excitation signal to the resolver according to the standard sine wave signal. in: The conditioning and shaping circuit includes a first-order integrator circuit for shaping and conditioning the PWM square wave signal into a triangular wave signal and an integrator filter circuit for shaping and conditioning the triangular wave signal into the standard sine wave signal. The integral filter circuit includes an RC integral filter circuit, a voltage follower, and a second-order integral filter circuit connected in sequence. The RC integral filter circuit includes a first resistor and a second capacitor. The voltage follower includes a second operational amplifier. The triangular wave signal is connected to the non-inverting input of the second operational amplifier through the first resistor. The non-inverting input of the second operational amplifier is grounded through the second capacitor. The inverting input of the second operational amplifier is connected to the output terminal of the second operational amplifier. The second-order integral filter circuit includes a second resistor, a third capacitor, a fourth capacitor, and a third operational amplifier. The output terminal of the second operational amplifier is connected to the non-inverting input of the third operational amplifier through the second resistor and to the output terminal of the third operational amplifier through the third capacitor. The non-inverting input of the third operational amplifier is grounded through the fourth capacitor, and the inverting input of the third operational amplifier is connected to the output terminal of the third operational amplifier.

2. The resolver excitation circuit according to claim 1, characterized in that, The first-order integrator circuit includes a first operational amplifier and a first capacitor. The inverting input of the first operational amplifier is connected to the PWM square wave signal and is connected to the output of the first operational amplifier through the first capacitor. The non-inverting input of the first operational amplifier is connected to a first reference voltage.

3. The resolver excitation circuit according to claim 1, characterized in that, The current negative feedback amplifier circuit includes a fourth operational amplifier, a first transistor, a second transistor, a third resistor, and a fourth resistor. The inverting input of the fourth operational amplifier is connected to the standard sine wave signal, and the non-inverting input of the fourth operational amplifier is grounded. The output of the fourth operational amplifier is connected to the control pins of the first transistor, the control pins of the second transistor, and one end of the third resistor. One switching pin of the first transistor is connected to the positive terminal of the DC power supply, and one switching pin of the second transistor is connected to the negative terminal of the DC power supply. The other switching pins of the first transistor, the other switching pins of the second transistor, and the other end of the third resistor are connected together as the output of the current negative feedback amplifier circuit, and connected to the inverting input of the fourth operational amplifier through the fourth resistor.

4. A resolver interface circuit, characterized in that, Including the resolver excitation circuit as described in any one of claims 1 to 3, and: The microcontroller system is used to output the excitation base frequency signal and the resistance adjustment signal; A feedback conditioning circuit is used to condition the original sine and cosine signals output by the rotary transformer into target sine and cosine signals. The original sine and cosine signals include two differential signals. The feedback conditioning circuit includes two differential signal receiving terminals, an enable control terminal, a first MOSFET, and a second MOSFET. The two differential signal receiving terminals are respectively connected to one switch pin of the first MOSFET and one switch pin of the second MOSFET. The other switch pins of the first MOSFET and the second MOSFET are grounded. The enable control terminal is connected to the control pins of the first MOSFET and the second MOSFET. The ADC module is used to digitize the target sine and cosine signals and then feed them back to the microcontroller system.

5. The resolver interface circuit according to claim 4, characterized in that, The feedback conditioning circuit includes a first-stage differential amplifier circuit and an inverting amplifier circuit connected in sequence.

6. The resolver interface circuit according to claim 4, characterized in that, The feedback conditioning circuit also includes a hysteresis comparator, which is used to detect the zero-crossing point based on the target sine and cosine signals and output it to the microcontroller system.

7. A driver, characterized in that, Includes the resolver interface circuit as described in any one of claims 4 to 6.

Images