Motor magnetic field signal measurement transmitter

Abstract

The invention discloses a motor magnetic field signal measurement transmitter, which relates to the technical field of magnetic field voltage and current signal measurement and comprises an MCU processing unit and a grounding resistor, one end of the grounding resistor is grounded, and the other end of the grounding resistor is connected with a power supply zero reference point; the input end of the MCU processing unit is connected with a magnetic field current measurement signal output circuit and a plurality of magnetic field voltage measurement signal output circuits, and the output end of the MCU processing unit is connected with a plurality of PWM isolation and conversion circuits; the magnetic field voltage measurement signal output circuit comprises a voltage division sampling circuit, a primary amplification and range switching circuit and a filtering and signal arrangement circuit which are sequentially connected to the MCU processing unit; the magnetic field current measurement signal output circuit comprises a primary amplification and measuring range switching circuit and a filtering and signal sorting circuit which are sequentially connected to the MCU processing unit. The device is high in voltage withstanding capability, fast in response, simple and easy to use, capable of simultaneously measuring four paths of signals between the positive electrode and the negative electrode of a magnetic field, adjustable in measuring range and convenient to use for generators of different specifications.

Description

Technical Field

[0001] The invention relates to the technical field of generator / phase modulator magnetic field voltage and current signal measurement, and in particular to a motor magnetic field signal measurement transmitter. Background Art

[0002] At present, most of the large and medium-sized synchronous generators / phase regulators use static excitation, that is, a special excitation transformer is used as the power supply, which is supplied to the motor excitation winding after rectification by the thyristor bridge. The magnetic field voltage output by the thyristor rectifier bridge to the motor excitation winding is a 6-fold positive and negative pulsating voltage, superimposed with rectification commutation gaps and spikes, and its waveform is relatively complex. Since the excitation power supply voltage of each type of generator / phase regulator is specially adapted and different from the standard voltage level. Therefore, in order to effectively monitor the magnetic field voltage, each type of generator / phase regulator needs to be adapted to a specific range of voltage transmitters. At present, excitation equipment manufacturers generally use universal voltage transmitters, but, On the one hand, the excitation power supply voltage of some existing generators / phase regulators is as high as 1500VAC. In the future, larger generators / phase regulators may exceed this voltage level. However, the linear optocouplers used in such transmitters have an insulation level lower than 1kV and a test withstand voltage of 4~5kV, resulting in insufficient insulation capacity, poor universality and practicality.

[0003] On the other hand, the measurement function of this type of transmitter is relatively simple, and it can usually only measure one magnetic field voltage, which cannot fully meet the user's needs to observe the magnetic field voltage signal.

[0004] Furthermore, the measured magnetic field voltage signal is usually connected to the fault recording device of the power plant, but the fault recording device has high requirements for the time constant of the measurement circuit. The time constant of the conventional model of the universal voltage transmitter is 100~200ms, which is too long for the power system, and reducing the time constant of the universal transmitter will lead to greater disturbance of the measurement result.

[0005] In addition, the patent document with the announcement number CN201273936Y discloses a generator magnetic field voltage upload device, which includes: a voltage divider for collecting the generator magnetic field voltage signal; an optical modulator connected to the voltage divider for converting the electrical signal collected by the voltage divider into an optical signal; an optical fiber transmission system connected to the optical modulator for receiving and transmitting the optical signal; an optical signal receiving converter connected to the optical fiber transmission system for converting the received optical signal into an electrical signal and outputting the electrical signal; and an isolated power supply connected to the optical modulator for providing working power to the optical modulator. The device can safely, reliably and accurately measure the high voltage voltage signal of the generator magnetic field. After careful analysis, it is found that the device adopts analog optical modulation technology, which transmits signals between high voltage and low voltage through optical fiber, thereby achieving two purposes of insulation isolation and long-distance transmission. However, the device is more suitable for transmission at the kilometer level. For signal transmission within a power plant building of tens of meters to one or two hundred meters, the technology is relatively complicated; and the circuits at the measuring end are all high-level to the ground, which is relatively inconvenient for maintenance and inspection personnel. Summary of the invention

[0006] In order to overcome the above problems existing in the prior art, the present invention provides a motor magnetic field signal measurement transmitter which has high voltage resistance, fast response, is simple and easy to use, and can simultaneously measure four signals between the positive and negative poles of the magnetic field.

[0007] To achieve the above purpose, the technical solution adopted by the present invention is as follows: A motor magnetic field signal measurement transmitter, the transmitter is used to simultaneously measure a magnetic field voltage signal and a magnetic field current signal including a voltage signal between positive and negative poles of a magnetic field, a voltage signal of a positive pole of a magnetic field to ground, and a voltage signal of a negative pole of a magnetic field to ground; the transmitter specifically comprises an MCU processing unit and a grounding resistor, one end of the grounding resistor is grounded, and the other end is connected to a power supply zero reference point; the input end of the MCU processing unit is connected to a magnetic field current measurement signal output circuit and a multi-channel magnetic field voltage measurement signal output circuit, and the output end of the MCU processing unit is connected to a plurality of PWM isolation and conversion circuits corresponding to the magnetic field current measurement signal output circuit and the magnetic field voltage measurement signal output circuit respectively; The magnetic field voltage measurement signal output circuit comprises a voltage-dividing sampling circuit, a primary amplification and range switching circuit, and a filtering and signal sorting circuit which are sequentially connected to the MCU processing unit; the multi-channel magnetic field voltage measurement signal output circuit is respectively connected to the positive pole of the magnetic field winding, the grounding base of the generator, and the negative pole of the magnetic field winding through the voltage-dividing sampling circuit; the voltage-dividing sampling circuit is used to reduce the voltage of the connected magnetic field voltage signal to a primary voltage signal and sample it; The magnetic field current measurement signal output circuit comprises a primary amplification and range switching circuit, a filtering and signal arrangement circuit which are sequentially connected to the MCU processing unit. The primary amplification and range switching circuit can access the magnetic field current signal through a Hall converter, and the Hall converter is used to convert the accessed magnetic field current signal into a primary voltage signal. Each primary amplification and range switching circuit is used to adjust the amplification factor, and amplify each primary voltage signal into a secondary voltage signal according to the adjusted amplification factor; each filtering and signal sorting circuit is used to filter and amplitude process each secondary voltage signal, and sort the processed secondary voltage signal into a tertiary voltage signal required by the MCU processing unit; the MCU processing unit is used to calculate the average voltage of each three-level voltage signal, and convert the average voltage into a PWM signal; the PWM isolation and conversion circuit is used to convert each PWM signal into a current signal, and output the voltage signal between the positive and negative poles of the magnetic field, the voltage signal of the positive pole of the magnetic field to the ground, the voltage signal of the ground to the negative pole of the magnetic field, and the magnetic field current signal.

[0008] The transmitter also includes a dual power supply module, which includes a 24V DC power supply circuit, a 220V AC / DC power supply circuit and a power adapter module. The 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel to each other and then supply power to the MCU processing unit, the magnetic field current measurement signal output circuit, the magnetic field voltage measurement signal output circuit and the PWM isolation and conversion circuit respectively through the power adapter module.

[0009] The 24V DC power supply circuit includes a DC diode chip, and the 220V AC / DC power supply circuit includes an AC / DC conversion module and a DC diode chip connected in series in sequence. The 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel via the DC diode chip.

[0010] The voltage-dividing sampling circuit comprises a sampling resistor and a plurality of voltage-dividing resistors connected in series in sequence. One end of the sampling resistor is connected to the output end of the last voltage-dividing resistor, and the other end is connected to the zero reference point of the power supply.

[0011] The primary amplification and range switching circuit comprises a differential amplifier and a range switching circuit. The range switching circuit is used to adjust the amplification factor of the differential amplifier. The differential amplifier is used to amplify the primary voltage signal into secondary voltage signals according to the adjusted amplification factor.

[0012] The output end of the differential amplifier is connected with a tap for local observation.

[0013] The filtering and signal arrangement circuit comprises a low-pass filter and an operational amplifier connected in sequence, wherein the low-pass filter is used for filtering, and the operational amplifier is used for amplitude processing of the secondary voltage signal and arranging the secondary voltage signal into a tertiary voltage signal.

[0014] The cut-off frequency of the low-pass filter is no higher than 1 kHz.

[0015] The current signal output by the PWM isolation and conversion circuit is 4-20mA.

[0016] The MCU processing unit is also provided with an RS485 bus interface and a CAN bus interface.

[0017] By adopting the above technical solution, the beneficial technical effects of the present invention are: 1. The measuring transmitter of the present invention comprises an MCU processing unit, a grounding resistor and a plurality of circuits, wherein: According to the characteristics that the generator excitation circuit is a floating ground system and the positive / negative impedance of the magnetic field coil is basically symmetrical to the ground, the high magnetic field voltage can be pulled down to a low voltage to the ground through the grounding resistor, so that except for the circuit where the voltage divider resistor is located, the rest of the circuits in the transmitter are low voltage to the ground. In this way, there is no need to set a high voltage isolation link from the high voltage input end to the output end of the PWM isolation and conversion circuit, which is not only safer, but also makes measurement more convenient.

[0018] The voltage-dividing sampling circuit has the advantage of high withstand voltage because it uses several voltage-dividing resistors connected in series. The withstand voltage test voltage for 1 minute can be as high as 10kV.

[0019] The primary amplification and range switching circuit can adjust the amplification factor of the primary voltage signal according to the actual working conditions, so that the transmitter can adapt to the different magnetic field voltages of various types of generators and make the best use of the instrument's range.

[0020] The filtering and signal conditioning circuit can achieve a balance between filtering (time delay) and output signal stability, so that the transmitter can obtain a stable measurement output when measuring highly pulsating magnetic field voltage. In summary, the present invention has high voltage resistance, fast response speed, and can simultaneously measure four signals, namely, the voltage signal between the positive and negative poles of the magnetic field, the voltage signal of the positive pole of the magnetic field to the ground, the voltage signal of the ground to the negative pole of the magnetic field, and the magnetic field current signal, which is beneficial to user signal analysis; and the measuring range (signal amplification factor) can be adjusted, which is convenient for use in generators of different specifications.

[0021] 2. The four signals measured simultaneously by the present invention have the same time constant and transmission medium, which is beneficial to the user's subsequent signal analysis.

[0022] 3. The present invention strikes a balance between filtering (time delay) and output signal stability. By setting the cutoff frequency of the low-pass filter to no higher than 1 kHz, it can achieve a technical effect of a response time of less than 25 ms.

[0023] 4. The present invention has a wide voltage adaptability, and its measurement range covers the current largest synchronous generator and phase-shifting phase magnetic field voltage; and the range switching link enables the transmitter to be used in various small, medium and large machines without changing the hardware structure, and can fully utilize the instrument range.

[0024] 5. The present invention has a wide range of applications and can be used for AC voltage measurement, especially for monitoring the secondary voltage of the excitation transformer. The conventional method uses PT to measure the secondary voltage of the excitation transformer, and it is necessary to consider that the commutation tip contained in the voltage may bring about magnetic saturation and harmonic heating problems, as well as phase deviation caused by electromagnetic conversion. However, the transmitter adopts resistance voltage division sampling, and there is no similar problem. In addition, the transmitter can be fully used for measuring AC or DC bus voltages of other similar voltage levels.

[0025] 6. The present invention has excellent fault tolerance, adopts resistance voltage division sampling, allows input of AC or DC of arbitrary waveform, and avoids accidents such as mistakenly adding DC into the PT circuit during previous tests.

[0026] 7. The present invention has a convenient test interface. During the machine-side test, the signal can be conveniently observed by using a multimeter, a recorder and other equipment through the tap.

[0027] 8. The present invention does not require hardware potentiometer calibration, but is calibrated in software through the field bus, and the output signal magnification can be adjusted within a certain range. In addition, the measurement results can be transmitted to the user's computer by communication through the RS485 bus interface and the CAN bus interface.

[0028] 9. The power supply of the present invention is highly safe. Conventional transmitters are all powered by a single power supply, while the present invention uses dual different external power supplies to improve the reliability of the transmitter. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of the present invention; The following are marked in the figure: 1. MCU processing unit, 2. voltage division sampling circuit, 3. primary amplification and range switching circuit, 4. filtering and signal sorting circuit, 5. PWM isolation and conversion circuit, 6. dual power supply module, 7. grounding resistor, 8. RS485 bus interface, 9. CAN bus interface; 2.1, sampling resistor, 2.2, voltage divider resistor; 3.1, differential amplifier, 3.2, range switching circuit, 3.3, tap; 4.1, low pass filter, 4.2, operational amplifier; 6.1. DC diode chip, 6.2. AC / DC conversion module, 6.3. Power adapter module. DETAILED DESCRIPTION

[0030] The present invention provides a motor magnetic field signal measurement transmitter, which is used to simultaneously measure magnetic field voltage signals and magnetic field current signals including the voltage signal between the positive and negative poles of the magnetic field, the voltage signal of the positive pole of the magnetic field to the ground, and the voltage signal of the negative pole of the magnetic field to the ground. Figure 1 As shown, it specifically includes an MCU processing unit 1, a grounding resistor 7 and a power supply zero reference point, all of which are arranged on a PCB circuit board. The input end of the MCU processing unit 1 is connected to a magnetic field current measurement signal output circuit and a multi-channel magnetic field voltage measurement signal output circuit, and the output end of the MCU processing unit 1 is connected to multiple PWM isolation and conversion circuits 5, and the multiple PWM isolation and conversion circuits 5 correspond one-to-one to the magnetic field current measurement signal output circuit and the magnetic field voltage measurement signal output circuit respectively.

[0031] The magnetic field voltage measurement signal output circuit includes a voltage divider sampling circuit 2, a primary amplification and range switching circuit 3, and a filtering and signal sorting circuit 4 which are sequentially connected to the MCU processing unit 1; the multi-channel magnetic field voltage measurement signal output circuit is respectively connected to the positive pole of the magnetic field winding, the generator grounding base and the negative pole of the magnetic field winding through the voltage divider sampling circuit 2, so as to measure three magnetic field voltage signals: the voltage signal between the positive and negative poles of the magnetic field, the voltage signal of the positive pole of the magnetic field to the ground, and the voltage signal of the negative pole of the magnetic field to the ground; the voltage divider sampling circuit 2 is used to reduce the voltage of the connected magnetic field voltage signal to a primary voltage signal and sample it.

[0032] The magnetic field current measurement signal output circuit includes a primary amplification and range switching circuit 3 and a filtering and signal sorting circuit 4 which are connected to the MCU processing unit 1 in sequence. The primary amplification and range switching circuit 3 can access the magnetic field current signal through a Hall converter, and the Hall converter is used to convert the accessed magnetic field current signal into a primary voltage signal and input it into the primary amplification and range switching circuit 3.

[0033] One end of the grounding resistor 7 is grounded, and the other end is connected to the zero reference point of the power supply; the magnetic field voltage can be pulled down to a low voltage relative to the ground through the grounding resistor 7, so that except for the circuit where the voltage divider resistor 2.2 is located at a high voltage relative to the ground, the rest of the circuits inside the transmitter are at a low voltage relative to the ground, which is safer to use.

[0034] Specifically, each of the above-mentioned primary amplification and range switching circuits 3 is used to adjust the amplification factor, and amplify each primary voltage signal into a secondary voltage signal according to the adjusted amplification factor; each filtering and signal sorting circuit 4 is used to filter and amplitude process each secondary voltage signal, and sort the processed secondary voltage signal into a tertiary voltage signal required by the MCU processing unit 1; the MCU processing unit 1 is used to calculate the average voltage of each three-level voltage signal, and convert the average voltage into a PWM signal; the PWM isolation and conversion circuit 5 is used to convert each PWM signal into a current signal, and output the voltage signal between the positive and negative poles of the magnetic field, the voltage signal from the positive pole of the magnetic field to the ground, the voltage signal from the ground to the negative pole of the magnetic field, and the magnetic field current signal.

[0035] It should be noted that the input voltage of the voltage-dividing sampling circuit 2 is usually below 2kV. After the voltage-dividing process, the voltage of the output primary voltage signal is usually around plus or minus 5V, and the voltage converted to the primary voltage signal by the Hall converter is also usually around plus or minus 5V. The primary amplification and range switching circuit 3 can set the corresponding amplification factor according to the size of the input voltage. Usually, the voltage of the secondary voltage signal processed by the primary amplification and range switching circuit 3 is usually 5-10V. The voltage of the tertiary voltage signal output by the filtering and signal sorting circuit 4 is usually 0-3.3V, and the current signal output by the PWM isolation and conversion circuit 5 is 4-20mA.

[0036] According to a preferred embodiment of the present invention, the above-mentioned transmitter also includes a dual power supply module 6, which includes a 24V DC power supply circuit, a 220V AC / DC power supply circuit and a power adapter module 6.3. The 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel to each other and respectively power the MCU processing unit 1, the magnetic field current measurement signal output circuit, the magnetic field voltage measurement signal output circuit and the PWM isolation and conversion circuit 5 through the power adapter module 6.3.

[0037] Furthermore, the 24V DC power supply circuit includes a DC diode chip 6.1, and the 220V AC / DC power supply circuit includes an AC / DC conversion module 6.2 and a DC diode chip 6.1 connected in series in sequence, and the 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel via the DC diode chip 6.1.

[0038] Those skilled in the art will appreciate that the 24V DC power supply circuit and the 220V AC / DC power supply circuit may be connected to an external power supply at the same time or individually, depending on actual conditions.

[0039] According to another preferred embodiment of the present invention, the voltage-dividing sampling circuit 2 comprises a sampling resistor 2.1 and a plurality of voltage-dividing resistors 2.2 connected in series, one end of the sampling resistor 2.1 is connected to the output end of the last voltage-dividing resistor 2.2, and the other end is connected to the zero reference point of the power supply.

[0040] It should be noted that the present invention does not limit the number and resistance of the voltage-dividing resistor 2.2. It is preferred that the input voltage is below 2 kV and the output voltage is approximately ±5 V.

[0041] According to another preferred embodiment of the present invention, the above-mentioned primary amplification and range switching circuit 3 includes a differential amplifier 3.1 and a range switching circuit 3.2, the magnetic field current measurement signal output circuit and the multi-channel magnetic field voltage measurement signal output circuit share the same range switching circuit 3.2, the range switching circuit 3.2 is used to adjust the amplification factor of the differential amplifier 3.1, and the differential amplifier 3.1 is used to amplify the primary voltage signal into secondary voltage signals according to the adjusted amplification factor.

[0042] Those skilled in the art will appreciate that the above-mentioned range switching circuit 3.2 can be implemented by using an existing conventional signal amplification circuit.

[0043] Furthermore, the output end of each differential amplifier 3.1 is also connected to a tap 3.3 for on-site observation, so that the measurement personnel can observe the voltage signal on-site through the tap 3.3.

[0044] According to another preferred embodiment of the present invention, the filtering and signal arrangement circuit 4 comprises a low-pass filter 4.1 and an operational amplifier 4.2 connected in sequence, wherein the low-pass filter 4.1 is used for filtering, and its cut-off frequency is generally not higher than 1kHz. The operational amplifier 4.2 is used for amplitude processing of the secondary voltage signal and arranging the secondary voltage signal into a tertiary voltage signal required by the MCU processing unit 1.

[0045] According to another preferred embodiment of the present invention, in order to facilitate the setting of the transmitter, the MCU processing unit 1 is also provided with an RS485 bus interface 8 and a CAN bus interface 9.

[0046] In summary, the present invention has high voltage resistance, fast response speed, and can simultaneously measure four signals, namely, the voltage signal between the positive and negative poles of the magnetic field, the voltage signal of the positive pole of the magnetic field to the ground, the voltage signal of the ground to the negative pole of the magnetic field, and the magnetic field current signal, which is beneficial to user signal analysis; and the measuring range (signal amplification factor) can be adjusted, which is convenient for use in generators of different specifications.

[0047] The above description is only a specific implementation mode of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other alternative features that are equivalent or have similar purposes; all the disclosed features, or all the steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A motor magnetic field signal measurement transmitter, the transmitter being used to simultaneously measure a magnetic field voltage signal and a magnetic field current signal, including a voltage signal between a positive and negative magnetic field pole, a voltage signal between a positive magnetic field pole and a ground, and a voltage signal between a negative magnetic field pole and a ground; the transmitter specifically comprises an MCU processing unit (1) and a grounding resistor (7), one end of the grounding resistor (7) being grounded, and the other end being connected to a power supply zero reference point; an input end of the MCU processing unit (1) being connected to a magnetic field current measurement signal output circuit and a multi-channel magnetic field voltage measurement signal output circuit, and an output end of the MCU processing unit (1) being connected to a plurality of PWM isolation and conversion circuits (5) corresponding one-to-one to the magnetic field current measurement signal output circuit and the magnetic field voltage measurement signal output circuit, respectively; The magnetic field voltage measurement signal output circuit comprises a voltage-dividing sampling circuit (2), a primary amplification and range switching circuit (3), and a filtering and signal arrangement circuit (4) which are sequentially connected to the MCU processing unit (1); the multi-channel magnetic field voltage measurement signal output circuits are respectively connected to the positive pole of the magnetic field winding, the generator grounding base, and the negative pole of the magnetic field winding through the voltage-dividing sampling circuit (2); the voltage-dividing sampling circuit (2) is used to reduce the voltage of the connected magnetic field voltage signal to a primary voltage signal and sample it; The magnetic field current measurement signal output circuit comprises a primary amplification and range switching circuit (3) and a filtering and signal arrangement circuit (4) which are sequentially connected to the MCU processing unit (1); the primary amplification and range switching circuit (3) can be connected to the magnetic field current signal through a Hall converter, and the Hall converter is used to convert the connected magnetic field current signal into a primary voltage signal; Each primary amplification and range switching circuit (3) is used to adjust the amplification factor, and amplify each primary voltage signal into a secondary voltage signal according to the adjusted amplification factor; each filtering and signal sorting circuit (4) is used to filter and amplitude process each secondary voltage signal, and sort the processed secondary voltage signal into a tertiary voltage signal required by the MCU processing unit (1); the MCU processing unit (1) is used to calculate the average voltage of each tertiary voltage signal, and convert the average voltage into a PWM signal; the PWM isolation and conversion circuit (5) is used to convert each PWM signal into a current signal, and output a voltage signal between the positive and negative poles of the magnetic field, a voltage signal between the positive pole of the magnetic field and the ground, a voltage signal between the ground and the negative pole of the magnetic field, and a magnetic field current signal.

2. The motor magnetic field signal measuring transmitter according to claim 1, characterized in that: The dual power supply module (6) comprises a 24V DC power supply circuit, a 220V AC / DC power supply circuit and a power adapter module (6.3). The 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel and respectively supply power to an MCU processing unit (1), a magnetic field current measurement signal output circuit, a magnetic field voltage measurement signal output circuit and a PWM isolation and conversion circuit (5) through the power adapter module (6.3).

3. The motor magnetic field signal measuring transmitter according to claim 2, characterized in that: The 24V DC power supply circuit comprises a DC diode chip (6.1), and the 220V AC / DC power supply circuit comprises an AC / DC conversion module (6.2) and a DC diode chip (6.1) connected in series in sequence, and the 24V DC power supply circuit and the 220V AC / DC power supply circuit are connected in parallel via the DC diode chip (6.1).

4. A motor magnetic field signal measuring transmitter according to any one of claims 1 to 3, characterized in that: The voltage-dividing sampling circuit (2) comprises a sampling resistor (2.1) and a plurality of voltage-dividing resistors (2.2) connected in series in sequence; one end of the sampling resistor (2.1) is connected to the output end of the last voltage-dividing resistor (2.2), and the other end is connected to a power supply zero reference point.

5. The motor magnetic field signal measuring transmitter according to claim 1, characterized in that: The primary amplification and range switching circuit (3) comprises a differential amplifier (3.1) and a range switching circuit (3.2), wherein the range switching circuit (3.2) is used to adjust the amplification factor of the differential amplifier (3.1), and the differential amplifier (3.1) is used to amplify the primary voltage signal into a secondary voltage signal according to the adjusted amplification factor.

6. The motor magnetic field signal measuring transmitter according to claim 5, characterized in that: The output end of the differential amplifier (3.1) is connected to a tap (3.3) for local observation.

7. The motor magnetic field signal measuring transmitter according to claim 1, characterized in that: The filtering and signal arrangement circuit (4) comprises a low-pass filter (4.1) and an operational amplifier (4.2) connected in sequence, the low-pass filter (4.1) being used for filtering, and the operational amplifier (4.2) being used for amplitude processing of a secondary voltage signal and arranging the secondary voltage signal into a tertiary voltage signal.

8. The motor magnetic field signal measuring transmitter according to claim 7, characterized in that: The cut-off frequency of the low-pass filter (4.1) is no higher than 1 kHz.

9. The motor magnetic field signal measuring transmitter according to claim 1, characterized in that: The current signal output by the PWM isolation and conversion circuit (5) is 4-20 mA.

10. The motor magnetic field signal measuring transmitter according to claim 1, characterized in that: The MCU processing unit (1) is also provided with an RS485 bus interface (8) and a CAN bus interface (9).

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