Traveling wave sensor direction control module based on PWM driving

Abstract

The utility model provides a traveling wave sensor direction control module based on PWM driving, which is applied to the technical field of driving control, and comprises a signal processing part and an output driving part, the signal processing part is used for converting a digital signal output by a main control module into a PWM signal of preset voltage and carrying out analog-to-digital conversion on the PWM signal to generate direct-current voltage, and the output driving part is used for outputting the direct-current voltage. An input reference voltage as an output driving part; the output driving part comprises a reference operational amplifier unit, a driving switch, a motor and a speed control system which are connected in sequence, and the reference operational amplifier unit adjusts the input voltage of the driving switch according to the input reference voltage and a feedback signal of the feedback resistance network, so that the driving switch outputs adaptive driving voltage; the angle of the traveling wave sensor is adjusted by controlling the motor to act through the motor and the speed control system, so that the energy collected by the traveling wave sensor is maximized. And the rotation angle of the motor is controlled by adjusting the output driving voltage, so that the position of the sensor is automatically adjusted.

Description

Technical Field

[0001] The utility model belongs to the technical field of drive control, and particularly relates to a traveling wave sensor direction control module based on PWM drive. Background Art

[0002] During the power test, it is necessary to install a fault monitoring device live at the position of the power line tower to realize the on-line monitoring of the power line. The fault monitoring device includes a non-contact sensor module. In actual use, the sensor module must be perpendicular to the laying direction of the cable to maximize the collected energy and achieve the highest sensor reception sensitivity. In the existing solutions, due to the fixed position of the sensor module, the on-site cable direction and the sensor module do not necessarily form a perpendicular angle, and the final sampling data is not referenceable.

[0003] In the prior art, most of the sensor angle is adjusted manually through traditional mechanical structures. However, the manual adjustment solution has great inadaptability to the installation environment of non-through towers. When the wire turns through the installation tower, it is difficult to determine the orientation of the sensor immediately. The manually locked direction often does not meet the actual sampling requirements and lacks flexibility. Summary of the Utility Model

[0004] In view of the above problems in the prior art, the purpose of the utility model is to provide a traveling wave sensor direction control module based on PWM drive, which controls the rotation angle of the motor by adjusting the output drive voltage, so as to realize the automatic adjustment of the sensor position.

[0005] A traveling wave sensor direction control module based on PWM drive includes a signal processing part and an output drive part connected to the main control module in sequence. The signal processing part is used to convert the digital signal output by the main control module into a PWM square wave signal with a preset voltage, and perform analog-to-digital conversion on the PWM square wave signal to generate a DC voltage, and use the DC voltage as the input reference voltage of the output drive part; the output drive part includes a reference operational amplifier unit, a drive switch, a motor and a speed change system connected in sequence. A feedback resistor network is also connected between the reference operational amplifier unit, the motor and the speed change system. The reference operational amplifier unit adjusts the input voltage of the drive switch according to the input reference voltage and the feedback signal of the feedback resistor network, so that the drive switch outputs an appropriate drive voltage, thereby controlling the motor action through the motor and the speed change system to adjust the angle of the traveling wave sensor, so as to maximize the energy collected by the traveling wave sensor.

[0006] Preferably, the reference operational amplifier unit includes operational amplifier U4, and the driving switch includes triodes T1 and T2. One input terminal of the operational amplifier U4 is connected to the reference voltage output by the signal processing section, and the other input terminal is connected to the feedback signal of the feedback resistor network. The output terminal of the operational amplifier U4 is connected to the base of the triode T1 through the resistor R8. The emitter of the triode T1 is grounded through the resistor R1. The collector of the triode T1 is connected to the base of the triode T2 through the resistor R2. The collector of the triode T2 outputs the driving voltage to the motor and the speed change system. The emitter of the triode T2 is connected to the power supply through the resistor R4.

[0007] Preferably, a protection unit is further connected between the driving switch and the motor and the speed change system. The protection unit includes triode T3. The base of the triode T3 is connected to the emitter of the triode T2. The collector of the triode T3 is connected to the base of the triode T2. The emitter of the triode T3 is connected to the collector of the triode T1 through the resistor R3 and is connected to the power supply.

[0008] Preferably, the feedback resistor network includes capacitors C7, C8, C9, resistor R14, and resistor R11 connected in parallel. The other ends of the capacitors C7, C8, C9, and resistor R14 are all grounded. The other end of the resistor R11 is grounded through the resistor R13. The signal between the resistor R11 and the resistor R13 is used as the feedback signal and is connected to the reference operational amplifier unit.

[0009] Preferably, the signal processing section includes transistor T4, reference source U5, and resistor-capacitor DAC unit. The gate of the transistor T4 is connected to the digital signal output by the main control module. The source of the transistor T4 is grounded. The drain of the transistor T4 is connected to the parallel-connected resistors R9 and reference source U5. The other end of the resistor R9 is connected to the power supply. The other end of the reference source U5 is grounded.

[0010] Preferably, the resistor-capacitor DAC unit includes resistors R15, R16, R10, capacitors C10, C11, and C12. One end of the resistor R15 is connected between the resistor R9 and the reference source U5, and the other end is connected to the parallel-connected resistors R16 and capacitor C10. The other end of the capacitor C10 is grounded. The other end of the resistor R16 is connected in series with the resistor R10, parallel-connected capacitors C11 and C12. The other end of the resistor R10 is connected to the input terminal of the reference operational amplifier unit. The other ends of the capacitors C11 and C12 are both grounded.

[0011] The beneficial effects of the present utility model are as follows: The direction control module of the traveling wave sensor based on PWM drive, through the mutual cooperation among the main control module, the signal processing part, and the output drive part, utilizes the main control module to adjust the duty cycle of the PWM wave, so that the output drive part outputs different drive voltages to control the rotation angle of the motor, thereby adjusting the position of the sensor connected to the output shaft of the motor to achieve automatic adjustment of the sensor position.

[0012] In addition, according to the magnitudes of the detection signals of different position sensors, the duty cycle of the PWM wave can be adjusted in real time until the detection signal of the sensor position is maximized. At this time, the position of the sensor is optimal, which can ensure the efficiency and sensitivity of cable monitoring. Description of the Drawings

[0013] The drawings are used to provide further understanding of the present utility model and constitute a part of the specification. They are used together with the embodiments of the present utility model to explain the present utility model and do not constitute a limitation to the present utility model. In the drawings:

[0014] Figure 1 is the system block diagram of the present utility model;

[0015] Figure 2 is the circuit diagram of the present utility model;

[0016] Figure 3 is the simulation waveform diagram of the present utility model. Detailed Embodiment

[0017] Embodiment 1

[0018] As Figure 1 shown, a direction control module of a traveling wave sensor based on PWM drive includes a signal processing part and an output drive part that are sequentially connected to the main control module. First, the output drive part includes a reference operational amplifier unit, a drive switch, a motor, and a speed change system that are sequentially connected. A feedback resistor network is also connected between the reference operational amplifier unit, the motor, and the speed change system. The reference operational amplifier unit adjusts the input voltage of the drive switch according to the input reference voltage and the feedback signal of the feedback resistor network, so that the drive switch outputs an appropriate drive voltage, thereby controlling the operation of the motor through the motor and the speed change system to adjust the angle of the traveling wave sensor and maximize the energy collected by the traveling wave sensor.

[0019] In this embodiment, the main control module includes an MCU, and the MCU is used to adjust the duty cycle of the output PWM signal. After startup, the MCU will pre-adjust the traveling wave sensor to rotate in steps of a certain angle, measure the magnitudes of the detection signals of the traveling wave sensor at different positions, and record the magnitudes of the detection signals at different positions of the sensor. Then the MCU fits a curve through the magnitudes of the detection signals of the traveling wave sensor at different positions and calculates the position with the best sensitivity.

[0020] By calculating the motor speed and rotation time when adjusting the traveling wave sensor to the optimal position, the MCU outputs PWM signals with different duty cycles to control the circuit operation, so that the traveling wave sensor rotates to the optimal position, ensuring the monitoring effect of the monitoring device.

[0021] Please refer to Figure 2 , the reference op-amp unit includes an operational amplifier U4, and the drive switch includes a triode T1 and a triode T2. One input terminal of the operational amplifier U4 is connected to the reference voltage output by the signal processing part, and the other input terminal is connected to the feedback signal of the feedback resistor network. The output terminal of the operational amplifier U4 is connected to the base of the triode T1 through a resistor R8. The emitter of the triode T1 is grounded through a resistor R1. The collector of the triode T1 is connected to the base of the triode T2 through a resistor R2. The collector of the triode T2 outputs a drive voltage to the motor and the speed change system. The emitter of the triode T2 is connected to the power supply through a resistor R4. Among them, the triode T2 plays a current limiting role to prevent the large current at the moment of startup from burning out the triode T2.

[0022] In addition, a protection unit is also connected between the drive switch and the motor and the speed change system. The protection unit includes a triode T3. The base of the triode T3 is connected to the emitter of the triode T2. The collector of the triode T3 is connected to the base of the triode T2. The emitter of the triode T3 is connected to the collector of the triode T1 through a resistor R3 and is connected to the power supply.

[0023] The feedback resistor network includes capacitors C7, C8, C9, resistor R14, and resistor R11 connected in parallel. The other ends of the capacitors C7, C8, C9, and resistor R14 are all grounded. The other end of the resistor R11 is grounded through a resistor R13. The signal between the resistor R11 and the resistor R13 is used as the feedback signal and is connected to the reference op-amp unit.

[0024] Secondly, the signal processing part is used to convert the digital signal output by the main control module into a PWM square wave signal with a preset voltage and perform analog-to-digital conversion on the PWM square wave signal to generate a DC voltage, so that the DC voltage serves as the input reference voltage for the output drive part.

[0025] Specifically, as Figure 2 shown, the signal processing part includes a transistor T4, a reference source U5, and a resistor-capacitor DAC unit. The gate of the transistor T4 is connected to the digital signal output by the main control module. The source of the transistor T4 is grounded. The drain of the transistor T4 is connected to the parallel-connected resistors R9 and reference source U5. The other end of the resistor R9 is connected to the power supply. The other end of the reference source U5 is grounded.

[0026] The resistor-capacitor DAC unit includes resistor R15, resistor R16, resistor R10, capacitor C10, capacitor C11, and capacitor C12. One end of resistor R15 is connected between resistor R9 and reference source U5, and the other end is connected to the parallel combination of resistor R16 and capacitor C10. The other end of capacitor C10 is grounded. The other end of resistor R16 is connected in series with resistor R10, and the parallel combination of capacitor C11 and capacitor C12. The other end of resistor R10 is connected to the input terminal of the reference op-amp unit. The other ends of capacitor C11 and capacitor C12 are both grounded.

[0027] As Figure 2 shown, multiple test points are set in the specific circuit, including AM1 for testing the collector current of triode T1, AM2 for testing the load current, VF1 for testing the PWM reverse signal and the output VF of reference source U5, VF2 for testing the voltage between the collector and emitter of triode T1, VF3 for testing the base voltage of triode T2, VF4 for testing the emitter voltage of triode T2, VG2 for testing the PWM source signal, VIN+ for testing the in-phase terminal signal of the op-amp, VIN- for testing the anti-phase terminal signal of the op-amp, and VOUT for testing the output.

[0028] In this embodiment, the simulation waveforms of each test point are as Figure 3 shown. Among them, the voltage of the PWM source signal at test point VG2 is 3V, with a high level of 4.3ms and a low level of 7.5ms. Therefore, the duty cycle of the low level is approximately 63%.

[0029] According to the simulation data analysis: when the MCU outputs a PWM signal with a duty cycle of 63% in this embodiment, the output voltage is approximately 7.1V; and when the frequency of the PWM signal is 85KHZ, the measured output ripple is small and the output is stable.

[0030] Working principle: For the traveling wave sensor direction control module based on PWM drive, when starting, the MCU outputs a PWM signal. Transistors T4 and reference source U5 convert the PWM signal output by the MCU into a PWM square wave signal with a certain voltage, and then the resistor-capacitor DAC unit converts the above PWM square wave signal into an analog DC voltage with a certain voltage as the reference voltage of the reference op-amp unit. Then the reference op-amp unit monitors the load voltage through the feedback resistor network, thereby adjusting the output to drive the drive switch. The MCU adjusts the duty cycle of the output PWM signal to control the change of the load voltage, thereby adjusting the motor speed, and adjusts the displacement accuracy of the traveling wave sensor through the speed change system to make the detection signal of the traveling wave sensor reach the maximum.

[0031] The above are only the preferred embodiments of the present utility model and are not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions recorded in the foregoing embodiments or perform equivalent replacements on some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A PWM-driven traveling wave sensor direction control module, characterized in that: It includes a signal processing part and an output driving part which are sequentially connected to the main control module, wherein the signal processing part is used to convert the digital signal output by the main control module into a PWM square wave signal of a preset voltage and to generate a DC voltage after performing analog-to-digital conversion on the PWM square wave signal, so that the DC voltage is used as an input reference voltage of the output driving part; The output drive part includes a reference operational amplifier unit, a drive switch, a motor and a speed change system connected in sequence. A feedback resistor network is also connected between the reference operational amplifier unit, the motor and the speed change system. The reference operational amplifier unit adjusts the input voltage of the drive switch according to the input reference voltage and the feedback signal of the feedback resistor network, so that the drive switch outputs an adaptive drive voltage, thereby controlling the motor action through the motor and the speed change system to adjust the angle of the traveling wave sensor, so as to maximize the energy collected by the traveling wave sensor.

2. The PWM-driven traveling wave sensor direction control module according to claim 1, characterized in that: The reference operational amplifier unit includes an operational amplifier U4, and the driving switch includes a transistor T1 and a transistor T2. One input end of the operational amplifier U4 is connected to the reference voltage output by the signal processing part, and the other input end is connected to the feedback signal of the feedback resistor network. The output end of the operational amplifier U4 is connected to the base of the transistor T1 through the resistor R8, the emitter of the transistor T1 is grounded through the resistor R1, the collector of the transistor T1 is connected to the base of the transistor T2 through the resistor R2, the collector of the transistor T2 outputs the driving voltage to the motor and the speed change system, and the emitter of the transistor T2 is connected to the power supply through the resistor R4.

3. The PWM-driven traveling wave sensor direction control module according to claim 2, characterized in that: A protection unit is also connected between the drive switch and the motor and the speed change system, and the protection unit includes a transistor T3, the base of the transistor T3 is connected to the emitter of the transistor T2, the collector of the transistor T3 is connected to the base of the transistor T2, and the emitter of the transistor T3 is connected to the collector of the transistor T1 through the resistor R3 and connected to the power supply.

4. The PWM-driven traveling wave sensor direction control module according to claim 1, characterized in that: The feedback resistor network includes capacitor C7, capacitor C8, capacitor C9, resistor R14 and resistor R11 connected in parallel. The other ends of the capacitors C7, C8, C9 and resistor R14 are all grounded, and the other end of the resistor R11 is grounded through a resistor R13. The signal between the resistors R11 and R13 is connected to the reference operational amplifier unit as a feedback signal.

5. The PWM-driven traveling wave sensor direction control module according to claim 1, characterized in that: The signal processing part includes a transistor T4, a reference source U5 and a resistor-capacitor DAC unit. The gate of the transistor T4 is connected to the digital signal output by the main control module, the source of the transistor T4 is grounded, the drain of the transistor T4 is connected to a resistor R9 and a reference source U5 in parallel, the other end of the resistor R9 is connected to a power supply, and the other end of the reference source U5 is grounded.

6. The PWM-driven traveling wave sensor direction control module according to claim 5, characterized in that: The RC DAC unit includes resistor R15, resistor R16, resistor R10, capacitor C10, capacitor C11, and capacitor C12. One end of the resistor R15 is connected between the resistor R9 and the reference source U5, and the other end is connected to the resistor R16 and capacitor C10 in parallel. The other end of the capacitor C10 is grounded. The other end of the resistor R16 is connected in series with the resistor R10, the capacitor C11, and the capacitor C12 in parallel. The other end of the resistor R10 is connected to the input end of the reference operational amplifier unit, and the other ends of the capacitors C11 and C12 are both grounded.

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