Overload measurement and control system and overload self-adaptive adjusting system of medium-sized high-voltage motor

Abstract

The invention discloses an overload measurement and control system and an overload self-adaptive adjusting system of a medium-sized high-voltage motor, and relates to the field of motor control. The invention aims to solve the problems that when an existing medium-sized high-voltage motor is in load operation, an overload degree judgment method is not accurate enough in detection and lacks self-adaptive adjustment. According to the excitation source, the power grid power supply is connected with the controllable PID voltage regulation module for power supply, and the first controllable amplification circuit is connected with the control board module. When the motor is in an overload working condition, the main control board can adjust the voltage amplification factor in the first controllable amplification circuit, adjust the power supply voltage of the motor, further adjust the slip ratio of the motor, and avoid the influence of the overload working condition on the winding insulation and operation performance of the motor. The signal acquisition module detects an electric signal in a motor stator winding and the rotating speed of a rotor rotating shaft on one hand to judge whether the motor is in an overload condition and the overload degree, and on the other hand, measures a slip ratio value change curve to provide a basis for the voltage reduction degree of a self-adaptive adjustment system.

Description

Technical Field

[0001] The invention belongs to the field of motor control. Background Art

[0002] Medium-sized high-voltage motors are powered by a three-phase AC power grid that is loaded into the three-phase symmetrical stator windings to realize the motor's excitation process and perform electromechanical energy conversion inside the motor, converting the electrical energy provided by the grid into mechanical power on the rotor shaft. Among them, the current signal fluctuations carried by the stator windings and the speed changes on the rotor shaft are key to determining whether the motor is operating in an overload condition. When the motor is overloaded, the current in the stator windings suddenly increases, the harmonic magnetic field inside the motor becomes larger, and the motor's core loss, no-load additional loss, load additional loss, and copper loss surge, increasing the motor's heat transfer burden. In severe cases, the motor will also produce abnormal noises and the rotor shaft speed will drop rapidly, causing insulation failures between the stator winding turns and between phases, delaying normal production tasks. However, when the existing medium-sized high-voltage motors are running under load, the method for determining the degree of overload has the problem of insufficient detection accuracy and lack of adaptive adjustment. Summary of the Invention

[0003] The present invention aims to solve the problem that the existing method for determining the overload degree of medium-sized high-voltage motors is not accurate enough and lacks adaptive adjustment when the motors are running under load. An overload measurement and control system and an adaptive adjustment system for medium-sized high-voltage motors are provided.

[0004] The overload measurement and control system for medium-sized high-voltage motors includes: a controllable PID voltage regulation module, a signal acquisition module, and a main control module;

[0005] The controllable PID voltage regulation module is used to connect the grid power supply to the stator three-phase winding of the medium-sized high-voltage motor;

[0006] The signal acquisition module is used to collect the instantaneous current and instantaneous voltage in the stator winding of the medium-sized high-voltage motor and the speed of the rotor shaft;

[0007] The main control module is used to multiply the instantaneous current and instantaneous voltage to obtain instantaneous power, and to determine that the medium-sized high-voltage motor is overloaded when the instantaneous current increases, the instantaneous voltage decreases, the speed decreases, and the instantaneous power is higher than the rated power.

[0008] Furthermore, the signal transmission module is used to transmit the instantaneous current and instantaneous voltage and the rotation speed of the rotor shaft obtained by the signal acquisition module to the main control module.

[0009] Furthermore, the signal transmission module includes: a first follower circuit, a second controllable amplifier circuit, a second follower circuit, a first bandpass filter and an A / D converter;

[0010] The signal input end of the first follower circuit serves as the signal input end of the signal transmission module, and the digital signal output end of the A / D converter serves as the signal output end of the signal transmission module;

[0011] The signal transmission module transmits the collected motor signal to the main control module in sequence through the first follower circuit, the second controllable amplifier circuit, the second follower circuit, the first bandpass filter and the A / D converter;

[0012] The parameter control signal input terminal of the second controllable amplifying circuit is connected to the second amplifying parameter control signal output terminal of the main control module.

[0013] Furthermore, the controllable PID voltage regulation module includes a PID circuit and a first controllable amplification circuit;

[0014] The input end of the PID circuit is used to connect to the power supply of the power grid, the modulation signal output end of the PID circuit is connected to the input end of the first controllable amplifier circuit, the voltage output end of the first controllable amplifier circuit is used to connect to the stator three-phase winding of the medium-sized high-voltage motor, and the amplification parameter output end of the first controllable amplifier circuit is connected to the first amplification parameter input end of the main control module.

[0015] Furthermore, the main control module includes: a main control board, a computer, an oscilloscope and a main control board power supply;

[0016] The main control board is an STM32 control chip and is used to collect motor signals;

[0017] The oscilloscope is used to display the motor signal collected by the main control board;

[0018] The computer is used to receive and store the motor signals collected by the main control board;

[0019] The main control board power supply is used to supply power to the main control board.

[0020] The overload adaptive regulation system for medium-sized high-voltage motors includes: a controllable PID voltage regulation module and a main control module;

[0021] When the medium-sized high-voltage motor is overloaded, the main control module drives the controllable PID voltage regulating module to adjust the voltage connected to the three-phase winding of the stator of the medium-sized high-voltage motor.

[0022] Furthermore, the controllable PID voltage regulation module includes: a PID circuit, a first controllable amplifier circuit, a second voltage follower circuit, a second bandpass filter and a first voltage follower circuit;

[0023] The driving signal output end of the main control module is input to the PID circuit through the first voltage follower circuit, the second bandpass filter and the second voltage follower circuit in sequence, and the PID circuit adjusts the amplification parameters of the first controllable amplifier circuit according to the driving signal;

[0024] The input end of the PID circuit is used to connect to the power supply of the power grid, the modulation signal output end of the PID circuit is connected to the input end of the first controllable amplifier circuit, the voltage output end of the first controllable amplifier circuit is used to connect to the stator three-phase winding of the medium-sized high-voltage motor, and the amplification parameter output end of the first controllable amplifier circuit is connected to the first amplification parameter input end of the main control module.

[0025] Furthermore, the above-mentioned overload adaptive regulation system for medium-sized high-voltage motors further includes a signal acquisition module;

[0026] The signal acquisition module is used to collect the instantaneous current and instantaneous voltage in the stator winding of the medium-sized high-voltage motor and the speed of the rotor shaft;

[0027] The main control module is also used to multiply the instantaneous current and instantaneous voltage to obtain instantaneous power, and determine that the medium-sized high-voltage motor is overloaded when the instantaneous current increases, the instantaneous voltage decreases, the speed decreases, and the instantaneous power is higher than the rated power.

[0028] Furthermore, the above-mentioned overload adaptive regulation system for medium-sized high-voltage motors also includes a signal transmission module, which is used to transmit the instantaneous current and instantaneous voltage obtained by the signal acquisition module and the speed of the rotor shaft to the main control module.

[0029] Furthermore, the signal transmission module includes: a first follower circuit, a second controllable amplifier circuit, a second follower circuit, a first bandpass filter and an A / D converter;

[0030] The signal input end of the first follower circuit serves as the signal input end of the signal transmission module, and the digital signal output end of the A / D converter serves as the signal output end of the signal transmission module;

[0031] The signal transmission module transmits the collected motor signal to the main control module in sequence through the first follower circuit, the second controllable amplifier circuit, the second follower circuit, the first bandpass filter and the A / D converter;

[0032] The parameter control signal input terminal of the second controllable amplifier circuit is connected to the second amplified parameter control signal output terminal of the main control module. The present invention is designed to determine whether a medium-sized high-voltage motor is overloaded and adaptively adjust the excitation voltage of the motor stator winding to prevent the overload condition from affecting the motor's performance. The present invention has the following beneficial effects:

[0033] First, the excitation source for starting a medium-sized high-voltage motor described in the present invention is powered by a grid power supply, a PID circuit, and a first controllable amplifier circuit, which is connected to the control board module. Upon detecting an overload condition for the motor, the main control board promptly issues a warning and adaptive adjustment command, adjusting the voltage gain in the first controllable amplifier circuit, regulating the motor's supply voltage, and, consequently, regulating the motor's slip rate, thereby preventing the overload condition from affecting the motor's winding insulation and operating performance.

[0034] Second, the signal acquisition module of the present invention detects the electrical signal in the stator winding of the motor and the speed of the rotor shaft to determine whether the motor is in an overload condition and the degree of overload. On the other hand, it measures the slip rate value change curve to provide a basis for the voltage reduction degree of the adaptive adjustment system. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is the structural diagram of the overload measurement and control system and adaptive regulation system for medium-sized high-voltage motors.

[0036] Figure 2 This is the T-type equivalent circuit diagram of one phase of a medium-sized high-voltage motor. DETAILED DESCRIPTION

[0037] The following will be combined with the accompanying drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other in the absence of conflict.

[0038] In order to solve the problems of heating, abnormal noise, and speed drop in medium-sized high-voltage motors under overload conditions, as well as the phenomenon of speed fluctuations when the load changes drastically, the following implementation methods are provided.

[0039] Specific implementation method 1: refer to Figure 1 and Figure 2Specifically describing this embodiment, the overload measurement and control system for medium-sized high-voltage motors described in this embodiment includes: a controllable PID voltage regulation module, a signal acquisition module, a signal transmission module and a main control module. The controllable PID voltage regulation module is used to connect the grid power supply to the three-phase stator winding of the medium-sized high-voltage motor; the signal acquisition module is used to collect the instantaneous current and instantaneous voltage of the stator winding of the medium-sized high-voltage motor, as well as the speed of the rotor shaft; the signal transmission module is used to transmit the collected electrical signal to the main control module; the main control module is used to perform calculations based on the electrical signal to determine whether the medium-sized high-voltage motor is overloaded. The details are as follows:

[0040] The controllable PID voltage regulation module includes: a PID circuit and a first controllable amplifying circuit.

[0041] The signal acquisition module includes: a stator winding acquisition port, a rotor shaft acquisition port and a sampling circuit.

[0042] The signal transmission module includes: a first follower circuit, a second controllable amplifying circuit, a second follower circuit, a bandpass filter and an A / D converter.

[0043] The main control module includes: a main control board, a computer, an oscilloscope and a main control board power supply.

[0044] The voltage output end of the grid power supply is connected to the voltage input end of the PID circuit, the voltage output end of the voltage input end is connected to the voltage input end of the first controllable amplifier circuit, and the voltage output end of the first controllable amplifier circuit is connected to the three-phase winding in the junction box of the medium-sized high-voltage motor. The above circuit provides a working signal for the medium-sized high-voltage motor, the stator armature winding cuts the rotor to form a rotating magnetic field and generates an induced electromotive force, and an electrical signal is generated in the stator winding.

[0045] The sampling circuit collects the instantaneous current signal and instantaneous voltage signal of the stator winding of the medium-sized high-voltage motor through the stator winding collection port, and the sampling circuit collects the instantaneous speed of the rotor shaft of the medium-sized high-voltage motor through the rotor shaft collection port.

[0046] The sampling circuit sends the collected motor signal to the first follower circuit. The signal output of the first follower circuit is connected to the signal input of the second controllable amplifier circuit, which is then connected to the signal input of the second follower circuit. The signal output of the second follower circuit is then connected to the signal input of the bandpass filter. The signal output of the bandpass filter is then connected to an A / D converter, and the digital signal output of the A / D converter is then connected to the main control board. The main control board adjusts the signal amplification factor of the second controllable amplifier circuit, forming a closed-loop control system. This allows for more complete measurement of the stator current, which represents the degree of overload, and the voltage, which represents the speed, and transmits these signals to the main control board for the issuance of adaptive adjustment instructions.

[0047] The main control board determines whether the medium-sized high-voltage motor is overloaded based on the collected motor signals. The specific judgment method is as follows:

[0048] The instantaneous current and voltage are multiplied to obtain the instantaneous power. When the instantaneous power exceeds the power threshold when the motor is running stably, the current medium-sized high-voltage motor is running unstably, and it is determined whether there is an overload at this time.

[0049] The method for determining whether a motor is overloaded is as follows: When a motor is overloaded, the load on the rotor shaft increases, and the required stator excitation current increases, causing the stator current in the circuit to increase. In severe overload conditions, the current may even exceed the rated current, potentially causing the motor winding to fail and burn out. At the same time, the resistance of the motor winding increases after an overload (after an overload, the stator winding current is high, copper loss increases, and local temperature rises, causing the resistance value to increase with temperature). Since the motor input voltage is the grid voltage, which is a fixed value, the winding voltage and speed will decrease. Therefore, if the instantaneous current increases, the instantaneous voltage decreases, the speed decreases, and the instantaneous power exceeds the rated power, it indicates an overload condition. (This is because if the motor is undervoltage, the current will increase, the voltage will decrease, and the speed will decrease, but the power will not increase under undervoltage conditions.)

[0050] The motor load level refers to the degree of load on the motor and is an important indicator for measuring the working status of the motor. Generally, the motor load level classification standard can be divided into the following four levels:

[0051] 1. Light load: refers to the load when the motor is working is less than 50% of the rated load.

[0052] 2. Medium load: refers to the load between 50% and 75% of the rated load when the motor is working.

[0053] 3. Heavy load: refers to the load between 75% and 110% of the rated load when the motor is working.

[0054] 4. Overload: refers to the load of the motor exceeding 110% of the rated load when it is working.

[0055] If the output power exceeds 110% of the rated load, it is considered overloaded.

[0056] The main control board module, controllable PID voltage regulation module, signal acquisition module and signal transmission module are all set in a protective shell made of sealed metal copper plates, isolating the current signal and motor leakage magnetic field interference in the working environment, and ensuring the accuracy of the signal acquisition process and the control instruction issuance process.

[0057] The oscilloscope is used to display the data collected by the main control board; the computer is used to receive and store the data collected by the main control board; the main control board adopts the STM32 control chip.

[0058] Specific implementation method 2: refer to Figure 1 and Figure 2 Specifically describing this embodiment, the adaptive adjustment system of the medium-sized high-voltage motor described in this embodiment includes: a controllable PID voltage regulation module, a signal acquisition module, a signal transmission module and a main control module. The controllable PID voltage regulation module is used to adjust the voltage of the three-phase stator winding of the medium-sized high-voltage motor connected to the grid power supply; the signal acquisition module is used to collect the instantaneous current and instantaneous voltage of the stator winding of the medium-sized high-voltage motor, as well as the speed of the rotor shaft; the signal transmission module is used to transmit the collected electrical signal to the main control module; the main control module is used to adaptively adjust the medium-sized high-voltage motor through the controllable PID voltage regulation module when the medium-sized high-voltage motor is overloaded. Specifically as follows:

[0059] The controllable PID voltage regulation module includes: a PID circuit, a first controllable amplifying circuit, a first voltage follower circuit, a bandpass filter, and a second voltage follower circuit.

[0060] The main control module includes: a main control board, a computer, an oscilloscope and a main control board power supply.

[0061] The sampling circuit collects the instantaneous current signal and instantaneous voltage signal of the stator winding of the medium-sized high-voltage motor through the stator winding collection port, and the sampling circuit collects the instantaneous speed of the rotor shaft of the medium-sized high-voltage motor through the rotor shaft collection port.

[0062] The sampling circuit sends the collected motor signal to the first follower circuit. The signal output of the first follower circuit is connected to the signal input of the second controllable amplifier circuit, which is then connected to the signal input of the second follower circuit. The signal output of the second follower circuit is then connected to the signal input of the first bandpass filter. The signal output of the first bandpass filter is then connected to an A / D converter, and the digital signal output of the A / D converter is then connected to the main control board. The main control board adjusts the amplification factor of the signal in the second controllable amplifier circuit, forming a closed-loop control system. This allows for more complete measurement of the stator current, which represents the degree of overload, and the voltage, which represents the speed, and transmits these signals to the main control board for the issuance of adaptive adjustment instructions.

[0063] The main control module is used to perform adaptive regulation on the medium-sized high-voltage motor through the controllable PID voltage regulation module when the medium-sized high-voltage motor is overloaded. The specific regulation method is as follows:

[0064] Calculate the instantaneous slip rate s based on the instantaneous speed of the rotor shaft of a medium-sized high-voltage motor:

[0065]

[0066] Where n is the instantaneous speed; n s is the synchronous speed, f is the power supply frequency of the stator side winding, the normal power frequency is 50Hz; p is the number of pole pairs of the stator winding.

[0067] The adaptive regulation process primarily involves the main control board detecting instantaneous current, voltage, speed, and power. Once an overload is detected, the main control board's signal is fed into the PID circuit via a voltage follower circuit and a bandpass filter, changing the stator winding input voltage and, in turn, the slip rate, achieving adaptive regulation. Simultaneously, the main control board receives the parameters of the controllable amplified signal from the adaptive regulation module to determine whether the signal meets the requirements. During the adaptive regulation process, the motor's signals (instantaneous current, voltage, speed, and power) are also transmitted to the main control board in real time, enabling real-time monitoring and adaptive regulation of the motor's status.

[0068] An adjustment signal is generated according to the overload degree of the medium-sized high-voltage motor. The adjustment signal adjusts the parameters of the first controllable amplifier circuit through the first voltage follower circuit, the second band-pass filter, the second voltage follower circuit and the PID circuit in sequence, thereby changing the input phase voltage input to the stator winding of the medium-sized high-voltage motor to change the slip rate, and finally realizes adaptive adjustment of the medium-sized high-voltage motor.

[0069] The main control board adjusts the amplification factor of the first controllable amplifier circuit for the signal, forming a closed-loop control system. This reduces the voltage at the motor power supply terminal and increases the slip. The main control board converts the speed signal collected by the signal acquisition module into a slip value and further adjusts the amplification factor in the first controllable amplifier circuit, forming a dual closed-loop control system for more precise adaptive control.

[0070] The main control board module, controllable PID voltage regulation module, signal acquisition module and signal transmission module are all set in a protective shell made of sealed metal copper plates, isolating the current signal and motor leakage magnetic field interference in the working environment, and ensuring the accuracy of the signal acquisition process and the control instruction issuance process.

[0071] The oscilloscope is used to display the data collected by the main control board; the computer is used to receive and store the data collected by the main control board; the main control board adopts the STM32 control chip.

[0072] The working principle of the present invention is as follows:

[0073] The grid serves as the power supply, supplying power to the three-phase windings in the junction box of a medium-sized high-voltage motor via a PID circuit and a first controllable amplifier circuit. The electromagnetic induction of the three-phase stator windings induces an electromotive force and a rotating magnetic field in the rotor, causing the rotor to rotate at a constant speed. Once the motor is running smoothly, a load is applied to the shaft. Sensors detect the phase currents in the three-phase stator windings and the rotor speed. These signals are transmitted to the main control board via a signal acquisition module and a signal transmission module. The main control board determines whether the motor is overloaded and the degree of overload. If an overload is detected, the main control board issues a warning and adaptive adjustment command. This signal is then fed into the PID circuit via a voltage follower circuit and a bandpass filter, changing the stator winding input voltage and, in turn, the slip rate. This enables adaptive motor regulation in overload conditions, preventing failure. The motor input voltage is adjusted by varying the amplification factor in the first controllable amplifier circuit, minimizing the impact of overload on winding insulation and performance. Simultaneously, an adaptive adjustment curve is generated during calculations, and the curve of winding current and speed changes with load is displayed on an oscilloscope.

[0074] The basis of the present invention is as follows:

[0075] like Figure 2 As shown, the terminal voltage U1 represents the input phase voltage of the induction motor, which is generated by the power grid through the PID circuit and the first controllable amplifier circuit and input to the stator three-phase winding; R1 is the resistance of one phase winding on the stator side; X σ is the stator side leakage reactance; I1 is the input phase current in the stator single-phase winding; R m is the excitation winding resistance; X m is the magnetizing reactance; I m is the excitation current; R2 is the resistance of one phase winding on the rotor side, X 2σ is the rotor side leakage reactance, I2 is the rotor side phase current; (1-s)R2′ / s is the single-phase load resistance on the shaft.

[0076] j is a vector with direction, E1 is the induced electromotive force on the stator side, and E2 is the value of the induced electromotive force on the rotor side converted to the stator side. The superscript “'” indicates the converted value of the parameter converted to the stator side.

[0077] The induced stator and rotor voltage equations are:

[0078]

[0079]

[0080]

[0081]

[0082] Depend on Figure 2From the equivalent circuit of the induction motor, it can be seen that the input power P1 supplied by the power supply to the medium-sized high-voltage motor is:

[0083]

[0084] is the power factor angle of the motor, indicating the phase angle at which U1 on the stator side leads I1; m1 is the number of phases of the motor, generally a three-phase induction motor, in which case m1 is 3.

[0085] Part of the input power P1 is consumed by the stator winding resistance R1 and converted into stator winding copper loss p Cu1 :

[0086]

[0087] Another part of the input power P1 is consumed by eddy current and hysteresis loss in the stator core. The alternating frequency of the magnetic field in the rotor core is sf1. Since the slip rate s is very small, the frequency of the magnetic field change in the rotor is very low, so the rotor core loss can be ignored. The total iron loss p Fe Corresponding to the excitation winding resistance R in the equivalent circuit m Loss on:

[0088]

[0089] Input power P1 minus stator winding copper loss p Cu1 and total iron loss p Fe After that, the remaining power is all transferred to the rotor through the air gap by electromagnetic induction, which is called electromagnetic power P e :

[0090] P e =P1-p Cu1 -p Fe .

[0091] From the equivalent circuit, we can see that:

[0092]

[0093] is the power factor angle of the motor, indicating the phase angle at which E' on the rotor side leads I2'.

[0094] Electromagnetic power P e Part of the energy is consumed in the rotor resistance and converted into heat energy, which is called rotor copper loss p Cu2 :

[0095]

[0096] m2 is the number of rotor phases.

[0097] Electromagnetic power Pe The remaining power is converted into mechanical energy, which is called total mechanical power P Ω , which corresponds to the power consumed by the one-phase load resistance (1-s)R2′ / s on the equivalent stationary shaft:

[0098]

[0099] Full mechanical power P Ω Part of the power is consumed in overcoming the mechanical loss p′ caused by bearing friction and wind friction resistance Ω , part of the power is consumed to overcome the additional loss p Δ The corresponding braking torque. From the total mechanical power P Ω Deduct p′ Ω and p Δ After the two parts are lost, the output power P2 is obtained, that is:

[0100] P2=P Ω -p′ Ω -p Δ .

[0101] The induction motor generates electromagnetic torque through the interaction of rotor current and magnetic field. The electromagnetic torque overcomes the resistance torque of the mechanical load and outputs mechanical power, thereby converting electrical energy into mechanical energy.

[0102]

[0103] T2=T e -T0,

[0104]

[0105] Where, T e is the electromagnetic torque, T0 is the no-load torque corresponding to the mechanical loss and additional loss, T2 is the output torque, n is the rotor shaft speed, n s is the synchronous electromagnetic speed, Ω s is the synchronous mechanical angular velocity, Ω mechanical angular velocity.

[0106] Although the present invention is described herein with reference to specific embodiments, it should be understood that these embodiments are merely illustrative of the principles and applications of the invention. It should be understood that many modifications may be made to the illustrative embodiments, and that other arrangements may be devised, without departing from the spirit and scope of the invention as defined by the appended claims. It should be understood that the various dependent claims and features described herein may be combined in ways other than those described in the original claims. It should also be understood that features described in conjunction with individual embodiments may be used in conjunction with other described embodiments.

Claims

1. Overload measurement and control system for medium-sized high-voltage motors, characterized in that: include: Controllable PID voltage regulation module, signal acquisition module and main control module; The controllable PID voltage regulating module is used to connect the grid power supply to the stator three-phase winding of the medium-sized high-voltage motor; The signal acquisition module is used to collect the instantaneous current and instantaneous voltage in the stator winding of the medium-sized high-voltage motor and the rotation speed of the rotor shaft; The main control module is used to multiply the instantaneous current and the instantaneous voltage to obtain the instantaneous power, and to determine that the medium-sized high-voltage motor is overloaded when the instantaneous current increases, the instantaneous voltage decreases, the speed decreases, and the instantaneous power is higher than the rated power.

2. The overload measurement and control system for medium-sized high-voltage motors according to claim 1 is characterized in that: It also includes a signal transmission module, which is used to transmit the instantaneous current and instantaneous voltage obtained by the signal acquisition module and the rotation speed of the rotor shaft to the main control module.

3. The overload measurement and control system for medium-sized high-voltage motors according to claim 2 is characterized in that: The signal transmission module includes: a first follower circuit, a second controllable amplifier circuit, a second follower circuit, a first bandpass filter and an A / D converter; The signal input end of the first follower circuit serves as the signal input end of the signal transmission module, and the digital signal output end of the A / D converter serves as the signal output end of the signal transmission module; The signal transmission module transmits the collected motor signal to the main control module in sequence through the first follower circuit, the second controllable amplifier circuit, the second follower circuit, the first bandpass filter and the A / D converter; The parameter control signal input terminal of the second controllable amplifying circuit is connected to the second amplifying parameter control signal output terminal of the main control module.

4. The overload measurement and control system for medium-sized high-voltage motors according to claim 1, 2 or 3, characterized in that: The controllable PID voltage regulation module includes a PID circuit and a first controllable amplification circuit; The input end of the PID circuit is used to connect to the power supply of the power grid, the modulation signal output end of the PID circuit is connected to the input end of the first controllable amplifier circuit, the voltage output end of the first controllable amplifier circuit is used to connect to the stator three-phase winding of a medium-sized high-voltage motor, and the amplification parameter output end of the first controllable amplifier circuit is connected to the first amplification parameter input end of the main control module.

5. The overload measurement and control system for medium-sized high-voltage motors according to claim 1, 2 or 3, characterized in that: The main control module includes: a main control board, a computer, an oscilloscope and a main control board power supply; The main control board is an STM32 control chip and is used to collect motor signals; The oscilloscope is used to display the motor signal collected by the main control board; The computer is used to receive and store the motor signal collected by the main control board; The main control board power supply is used to supply power to the main control board.

6. Overload adaptive regulation system for medium-sized high-voltage motors, characterized in that: include: Controllable PID voltage regulation module and main control module; When the medium-sized high-voltage motor is overloaded, the main control module drives the controllable PID voltage regulating module to adjust the voltage connected to the three-phase winding of the stator of the medium-sized high-voltage motor.

7. The overload adaptive regulation system for medium-sized high-voltage motors according to claim 6 is characterized in that: The controllable PID voltage regulation module comprises: a PID circuit, a first controllable amplifier circuit, a second voltage follower circuit, a second bandpass filter and a first voltage follower circuit; The driving signal output end of the main control module is input to the PID circuit through the first voltage follower circuit, the second bandpass filter and the second voltage follower circuit in sequence, and the PID circuit adjusts the amplification parameter of the first controllable amplifier circuit according to the driving signal; The input end of the PID circuit is used to connect to the power supply of the power grid, the modulation signal output end of the PID circuit is connected to the input end of the first controllable amplifier circuit, the voltage output end of the first controllable amplifier circuit is used to connect to the stator three-phase winding of a medium-sized high-voltage motor, and the amplification parameter output end of the first controllable amplifier circuit is connected to the first amplification parameter input end of the main control module.

8. The overload adaptive regulation system for medium-sized high-voltage motors according to claim 6 or 7, characterized in that: Also includes a signal acquisition module; The signal acquisition module is used to collect the instantaneous current and instantaneous voltage in the stator winding of the medium-sized high-voltage motor and the rotation speed of the rotor shaft; The main control module is also used to multiply the instantaneous current and the instantaneous voltage to obtain the instantaneous power, and determine that the medium-sized high-voltage motor is overloaded when the instantaneous current increases, the instantaneous voltage decreases, the speed decreases, and the instantaneous power is higher than the rated power.

9. The overload adaptive regulation system for medium-sized high-voltage motors according to claim 8, characterized in that: It also includes a signal transmission module, which is used to transmit the instantaneous current and instantaneous voltage obtained by the signal acquisition module and the rotation speed of the rotor shaft to the main control module.

10. The overload adaptive regulation system for medium-sized high-voltage motors according to claim 9, characterized in that: The signal transmission module includes: a first follower circuit, a second controllable amplifier circuit, a second follower circuit, a first bandpass filter and an A / D converter; The signal input end of the first follower circuit serves as the signal input end of the signal transmission module, and the digital signal output end of the A / D converter serves as the signal output end of the signal transmission module; The signal transmission module transmits the collected motor signal to the main control module in sequence through the first follower circuit, the second controllable amplifier circuit, the second follower circuit, the first bandpass filter and the A / D converter; The parameter control signal input terminal of the second controllable amplifying circuit is connected to the second amplifying parameter control signal output terminal of the main control module.

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