Three-phase asynchronous motor simulator and three-phase asynchronous motor parameter change simulation method

Abstract

The invention provides a three-phase asynchronous motor simulator which is used for teaching demonstration of a three-phase asynchronous motor and is characterized in that the three-phase asynchronous motor simulator comprises a three-phase asynchronous motor simulator body and an operation simulation model, the operation simulation model is a real-time digital model and operates on a single-chip microcomputer of a control panel of the three-phase asynchronous motor simulator body; the three-phase asynchronous motor simulator body further comprises a display panel and a plurality of channel interfaces, the plurality of channel interfaces are connected in series through resistors for voltage division, and positive half-cycle signals are input to an ADC interface of the single-chip microcomputer for acquisition; the AC-DC module is used for converting an external 220V alternating-current power supply into a low-voltage direct-current power supply and supplying power to the single-chip microcomputer and an LCD power supply of the display panel, and meanwhile, a three-phase asynchronous motor parameter change simulation method matched with the single-chip microcomputer and the display panel is provided; the problem that a three-phase asynchronous motor simulator in the prior art is single in function, complex in structure and high in maintenance cost is solved.

Description

Technical Field

[0001] The present invention relates to the technical field of motor simulation equipment, in particular to a three-phase asynchronous motor simulator and a three-phase asynchronous motor parameter change simulation method. Background Art

[0002] With the popularization of intelligent manufacturing concepts, three-phase asynchronous motors have experienced rapid development in China. This has led to an urgent demand for technical personnel in three-phase asynchronous motors. For students majoring in related fields, the working principles, wiring methods, rotation direction determination, and terminal wiring of three-phase asynchronous motors are important basic knowledge that must be mastered, and they also serve as a starting point for further study.

[0003] The practical training course on three-phase asynchronous motors is an important part of the talent training process. The learning process should follow the principle of being student-centered and focusing on cultivating students' practical ability. Usually, practical training allows students to master the basic knowledge related to the working principles and operation principles of industrial robots. However, students are usually unable to operate three-phase asynchronous motors on site. With the teacher's simple explanation, students often cannot feel it intuitively, resulting in students being unable to truly master the knowledge points and unable to apply what they have learned.

[0004] In this context, three-phase asynchronous motor simulators have emerged as a teaching tool to enable students to better conduct practical training in industrial robots. However, currently available three-phase asynchronous motor simulators have at least the following drawbacks:

[0005] 1) The three-phase asynchronous motor simulator has a single function. In the context of the rapid development of three-phase asynchronous motors, the teaching tool often lags behind the three-phase asynchronous motors used in practice. As a result, when students complete their studies and enter the workplace, they often find it difficult to apply what they have learned.

[0006] 2) The structure is complex and the maintenance cost is high. When a three-phase asynchronous motor appears, it is difficult to repair;

[0007] 3) Simulation software focuses on demonstration functions and lacks timely input control capabilities.

[0008] In order to solve one or more aspects of the above problems, there is an urgent need for a newer and more advanced three-phase asynchronous motor simulator to better complete the teaching work. Summary of the Invention

[0009] The present invention proposes a three-phase asynchronous motor simulator and a method for simulating the parameter changes of a three-phase asynchronous motor, which solves the defects of the existing three-phase asynchronous motor simulators, such as single function, complex structure, and high maintenance cost. The technical solution of the present invention is achieved as follows:

[0010] A three-phase asynchronous motor simulator is used for teaching demonstrations of three-phase asynchronous motors. It includes a three-phase asynchronous motor simulator body and an operation simulation model. The operation simulation model is a real-time digital model that runs on a single-chip microcomputer on a control board of the three-phase asynchronous motor simulator body. The three-phase asynchronous motor simulator body also includes a display panel and multiple channel interfaces. The multiple channel interfaces divide the voltage by series resistors, and take the positive half-cycle signal and input it into the single-chip microcomputer ADC interface for collection; it also includes an AC-DC module, which is used to convert an external 220V AC power supply into a low-voltage DC power supply to power the single-chip microcomputer and the LCD power supply of the display panel.

[0011] As a preferred technical solution, there are 6 channel interfaces, and the three-phase asynchronous motor simulator body collects signals through ADC and DMA, respectively collecting signal values ​​of 6 channels, U1 / V1 / W1 / U2 / V2 / W2.

[0012] The method for simulating parameter changes of a three-phase asynchronous motor, using any three-phase asynchronous motor simulator, includes the following steps:

[0013] Use ADC and DMA to collect signals, collect signal values ​​of multiple channel interfaces respectively, and perform preliminary processing on the sampled data and save them;

[0014] The multi-sampled data is processed as follows: the sampled data is analyzed to determine the rising and falling cycles, thereby calculating the number of sampled cycles of each channel signal; the cycles of multiple channels are averaged as the effective cycle; based on the calculated effective cycle value and the sampled value, the voltage effective value of each channel is calculated, and the phase angle between each two channels is calculated;

[0015] The operating parameter status of the three-phase asynchronous motor is qualitatively judged based on the processing results of the sampling data.

[0016] As a preferred technical solution, for the signal values ​​of multiple channels, an arithmetic mean filtering method is used to perform preliminary processing on the sampled data and save them. The sampling period of the filtered data is 50 μs.

[0017] As a preferred technical solution, when calculating the effective cycle, the cycles of multiple channels are averaged, and then the square difference between the cycle of each channel and the average value is calculated. If the sum of the square differences is too large, the calculated values ​​of the channels with too large square differences are eliminated; repeat this step until the sum of the square differences is within the set range, and then the average value of the remaining channels is calculated as the actual power cycle value.

[0018] As a preferred technical solution, the wiring condition is determined according to the voltage RMS value and the pairwise phase angle according to the following rules:

[0019] If the voltage RMS values ​​are close and the phase angles between them are close to 0°, then the two are judged to be connected together;

[0020] If the voltage difference is nearly half and the phase angle between them is close to 0°, the end with the higher voltage is connected to the power supply and the other end is left floating.

[0021] If the voltage is high and the phase angle between the two lines is close to 120° or 240°, it is determined that both lines are connected to a valid power source;

[0022] If the voltage is approximately 0 and the pairwise phase angle is close to 0°, it is determined to be floating.

[0023] As a preferred technical solution, the voltages between U1 / U2, V1 / V2, and W1 / W2 are calculated based on the phase angles, voltages, and wiring conditions of each pair:

[0024]

[0025] Where u is the final calculated voltage value; u1 / u2 are the voltage values ​​of the two terminals connected to the power supply; and θ is the angle between the two terminals.

[0026] As a preferred technical solution, the wiring method and rotation direction are determined based on the wiring conditions and phase angle between the terminals. The specific rules are as follows:

[0027] If U1 / V1 / W1 are connected together, the voltage is 0, and the phase angle between the three terminals U2 / V2 / W2 is about 120°, then it is determined to be a star connection, clockwise (L1, L2, L3);

[0028] If U1 / V1 / W1 are connected together, the voltage is 0, and the phase angle between the three terminals U2 / V2 / W2 is about 240°, then it is determined to be a star connection, counterclockwise (L1, L3, L2);

[0029] If U2 / V2 / W2 are connected together, the voltage is 0, and the phase angle between the three terminals U1 / V1 / W1 is about 120°, then it is determined to be a star connection, clockwise (L1, L2, L3);

[0030] If U2 / V2 / W2 are connected together, the voltage is 0, and the phase angle between the three terminals U1 / V1 / W1 is about 240°, then it is determined to be a star connection, counterclockwise (L1, L3, L2);

[0031] If U1 / V2, V1 / W2, and W1 / U2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 120°, then it is determined to be a triangle connection, clockwise (L1, L2, L3);

[0032] If U1 / V2, V1 / W2, and W1 / U2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is approximately 240°, then it is determined to be a triangle connection, counterclockwise (L1, L3, L2);

[0033] If U1 / W2, V1 / U2, and W1 / V2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 120°, then it is determined to be a triangle connection, clockwise (L1, L2, L3);

[0034] If U1 / W2, V1 / U2, and W1 / V2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is approximately 240°, then it is determined to be a triangle connection, counterclockwise (L1, L3, L2);

[0035] Others are incorrect wiring methods.

[0036] As a preferred technical solution, the rotation speed is calculated based on the wiring method and the effective period, and the speed is inversely proportional to the effective period.

[0037] Compared with the existing technology, this solution has the following beneficial effects:

[0038] 1) Design simulation devices and run simulation model algorithms based on the latest three-phase asynchronous motor structure, which can objectively simulate the three-phase asynchronous motors used in practice, so that students can understand and master the latest three-phase asynchronous motor structure and apply what they have learned.

[0039] 2) It is equipped with multiple channel interfaces, which can simulate various motor operating parameters.

[0040] 3) Simple structure, low cost, easy to promote and use on a large scale and convenient maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0042] Figure 1 A flow chart of a method for simulating parameter changes of a three-phase asynchronous motor according to the present invention;

[0043] Figure 2 This is a schematic structural diagram of a three-phase asynchronous motor simulator according to the present invention;

[0044] Figure 3This is a schematic diagram of the control board of the three-phase asynchronous motor simulator of the present invention;

[0045] Figure 4 This is a schematic diagram of the display panel of the three-phase asynchronous motor simulator of the present invention.

[0046] Description of reference numerals:

[0047] 11-display panel; 12-microcontroller; 13-channel interface. DETAILED DESCRIPTION

[0048] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] Reference Figure 2 A three-phase asynchronous motor simulator is used for teaching demonstration of three-phase asynchronous motors, including a three-phase asynchronous motor simulator body and an operation simulation model. The operation simulation model is a real-time digital model, which runs on the single-chip microcomputer 12 of the three-phase asynchronous motor simulator body control board. The three-phase asynchronous motor simulator body also includes a display panel 11 and multiple channel interfaces 13. The multiple channel interfaces 13 divide the voltage through series resistors, and take the positive half-cycle signal and input it to the single-chip microcomputer ADC interface for collection; it also includes an AC-DC module, which is used to convert the external 220V AC power supply into a low-voltage DC power supply to power the single-chip microcomputer and the LCD power supply of the display panel. There are 6 channel interfaces, and the three-phase asynchronous motor simulator body performs signal acquisition through ADC and DMA, and respectively collects the signal values ​​of 6 channels, U1 / V1 / W1 / U2 / V2 / W2. See the control board schematic diagram of the three-phase asynchronous motor simulator. Figure 3 , the display panel schematic diagram of the three-phase asynchronous motor simulator is shown in Figure 4 .

[0050] The supporting algorithm of the three-phase asynchronous motor simulator is as follows:

[0051] 1. Signal Acquisition

[0052] Signal acquisition is performed using the ADC and DMA, collecting signal values ​​from six channels (U1, V1, W1, U2, V2, and W2). The sampled data is initially processed and saved using arithmetic averaging filtering. The filtered data is sampled over a 50µs period.

[0053] 2. Sampling data processing:

[0054] Step a) cycle calculation: analyze the sampled data, determine the rising cycle and the falling cycle, and thus calculate the cycle sampling number of each channel signal.

[0055] In step b) effective cycle calculation, average the cycle values ​​of the six channels and calculate the squared difference between each channel's cycle and the average. If the sum of the squared differences is too large, discard the calculated value of the channel with the excessive squared difference. Repeat this step until the sum of the squared differences is within a certain range. Finally, calculate the average value of the remaining channels as the actual power cycle value.

[0056] Step c) Calculate the effective value of the voltage of each channel and the phase angle between each two channels based on the calculated effective period value and the sampling value.

[0057] Step d) Determine the wiring condition based on the voltage RMS and pairwise phase angles:

[0058] When the voltage RMS values ​​are close and the phase angles between them are close to 0°, it means that the two are connected together;

[0059] When the voltage difference is nearly half and the phase angle between them is close to 0°, it means that the end with higher voltage is connected to the power supply and the other end is left floating;

[0060] When the voltage is high and the phase angle between the two lines is close to 120° or 240°, it means that both lines are connected to a valid power source;

[0061] When the voltage is approximately 0 and the pairwise phase angle is close to 0°, it indicates floating.

[0062] In step e), the voltages between U1 / U2, V1 / V2, and W1 / W2 are calculated based on the phase angles, voltages, and wiring conditions. The calculation formula is as follows:

[0063]

[0064] u is the final calculated voltage value; u1 / u2 are the voltage values ​​of the two terminals connected to the power supply; θ is the angle between them.

[0065] Step f) Determine the wiring method and rotation direction based on the wiring conditions and phase angle between the terminals:

[0066] When U1 / V1 / W1 are connected together and the voltage is 0, the phase angle between the three terminals U2 / V2 / W2 is about 120°: star connection, clockwise (L1, L2, L3);

[0067] When U1 / V1 / W1 are connected together and the voltage is 0, the phase angle between the three terminals U2 / V2 / W2 is about 240°: star connection, counterclockwise (L1, L3, L2);

[0068] When U2 / V2 / W2 are connected together and the voltage is 0, the phase angle between the three terminals U1 / V1 / W1 is about 120°: star connection, clockwise (L1, L2, L3);

[0069] When U2 / V2 / W2 are connected together and the voltage is 0, the phase angle between the three terminals U1 / V1 / W1 is about 240°: star connection, counterclockwise (L1, L3, L2);

[0070] When U1 / V2, V1 / W2, and W1 / U2 are connected together, the phase angle between the three terminals of U1 / V1 / W1 is about 120°: triangle connection, clockwise (L1, L2, L3);

[0071] When U1 / V2, V1 / W2, and W1 / U2 are connected together, the phase angle between the three terminals of U1 / V1 / W1 is about 240°: triangle connection, counterclockwise (L1, L3, L2);

[0072] When U1 / W2, V1 / U2, and W1 / V2 are connected together, the phase angle between the three terminals of U1 / V1 / W1 is about 120°: triangle connection, clockwise (L1, L2, L3);

[0073] When U1 / W2, V1 / U2, and W1 / V2 are connected together, the phase angle between the three terminals of U1 / V1 / W1 is about 240°: triangle connection, counterclockwise (L1, L3, L2);

[0074] Others are incorrect wiring methods.

[0075] Step g) calculating the rotation speed according to the connection mode and the effective period, wherein the speed is inversely proportional to the effective period.

[0076] Step h) Displaying the simulation determination result on the display panel 11:

[0077] When the connection is valid: the fan blade image rotation angle is calculated, and the image data after rotation is calculated and displayed; when the connection is invalid: the image does not move

[0078] Displays the wiring mode; does not display if the wiring is invalid

[0079] Displays the wiring sequence and the effective value of the voltage; when the wiring is invalid, the effective connection analog coil voltage is displayed

[0080] When the wiring is valid, the LED is always on, green when turning clockwise and yellow when turning counterclockwise; when the wiring is invalid, the red light flashes.

[0081] Compared to existing motor simulation devices, this one offers the following advantages: The simulation device and operating model algorithm are designed based on the latest three-phase asynchronous motor structure, enabling objective simulation of practical three-phase asynchronous motors. This allows students to understand and master the latest three-phase asynchronous motor structures, enabling them to apply their knowledge. Multiple channel interfaces enable simulation of various motor operating parameters. Its simple structure and low cost facilitate large-scale deployment and convenient maintenance.

[0082] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. Three-phase asynchronous motor simulator, used for teaching demonstration of three-phase asynchronous motor, characterized by: The three-phase asynchronous motor simulator comprises a three-phase asynchronous motor simulator body and an operation simulation model. The operation simulation model is a real-time digital model, which runs on a single-chip microcomputer of a control board of the three-phase asynchronous motor simulator body. The three-phase asynchronous motor simulator body also comprises a display panel (11) and a plurality of channel interfaces (13). The plurality of channel interfaces (13) divide voltages by series resistors, and take positive half-cycle signals and input them into an ADC interface of a single-chip microcomputer (12) for collection. The three-phase asynchronous motor simulator also comprises an AC-DC module, which is used to convert an external 220V AC power supply into a low-voltage DC power supply to supply power to the single-chip microcomputer (12) and the LCD power supply of the display panel.

2. The three-phase asynchronous motor simulator according to claim 1, characterized in that: There are 6 channel interfaces, and the three-phase asynchronous motor simulator body collects signals through ADC and DMA, and collects signal values ​​of 6 channels, namely U1 / V1 / W1 / U2 / V2 / W2.

3. A method for simulating parameter changes of a three-phase asynchronous motor, characterized in that: The three-phase asynchronous motor simulator as described in any one of claims 1 to 2 is used, comprising the following steps: The signal is collected through ADC and DMA, and the signal values ​​of multiple channel interfaces are collected respectively, and the sampled data are preliminarily processed and saved; The sampled data are processed as follows: the sampled data are analyzed to determine the rising cycle and the falling cycle, thereby calculating the number of sampled cycles of each channel signal; the average value of the cycles of multiple channels is taken as the effective cycle; based on the calculated effective cycle value and the sampled value, the voltage effective value of each channel is calculated, and the phase angle between two channels is calculated; A qualitative judgment is made on the operating parameter status of the three-phase asynchronous motor based on the processing results of the sampling data.

4. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 3, characterized in that: For the signal values ​​of multiple channels, the arithmetic mean filtering method is used to perform preliminary processing on the sampled data and save them. The sampling period of the filtered data is 50μs.

5. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 3, characterized in that: When calculating the effective period, the periods of multiple channels are averaged, and then the square difference between the period of each channel and the average value is calculated. If the sum of the square differences is too large, the calculated value of the channel with the large square difference is eliminated. Repeat this step until the sum of the square differences is within the set range, and then calculate the average value of the remaining channels as the actual power cycle value.

6. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 1, characterized in that: Determine the wiring situation according to the voltage effective value and the phase angle between the two according to the following rules: If the voltage effective values ​​are close and the phase angles are close to 0°, then the two are judged to be connected together; If the voltage difference is nearly half and the phase angle between the two is close to 0°, the end with the higher voltage is connected to the power supply and the other end is left floating; If the voltage is high and the phase angle between the two is close to 120° or 240°, it is determined that both wires are connected to a valid power source; If the voltage is approximately 0 and the phase angle between them is close to 0°, it is determined to be floating.

7. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 1, characterized in that: According to the phase angle, voltage and wiring conditions, the voltages between U1 / U2, V1 / V2 and W1 / W2 are calculated respectively: Among them, u is the final calculated voltage value; u1 and u2 are the power supply voltage values ​​of the two terminals respectively; θ is the angle between them.

8. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 6, characterized in that: Determine the wiring mode and rotation direction based on the wiring conditions and phase angle between the terminals. The determination rules are as follows: If U1 / V1 / W1 are connected together, the voltage is 0, and the phase angle between the three terminals U2 / V2 / W2 is about 120°, then it is determined to be: star connection, clockwise (L1, L2, L3); If U1 / V1 / W1 are connected together, the voltage is 0, and the phase angle between the three terminals U2 / V2 / W2 is about 240°, then it is determined to be: star connection, counterclockwise (L1, L3, L2); If U2 / V2 / W2 are connected together, the voltage is 0, and the phase angle between the three terminals U1 / V1 / W1 is about 120°, then it is determined to be: star connection, clockwise (L1, L2, L3); If U2 / V2 / W2 are connected together, the voltage is 0, and the phase angle between the three terminals U1 / V1 / W1 is about 240°, then it is determined to be: star connection, counterclockwise (L1, L3, L2); If U1 / V2, V1 / W2, and W1 / U2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 120°, then it is determined as: triangle connection, clockwise (L1, L2, L3); If U1 / V2, V1 / W2, and W1 / U2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 240°, it is determined as: triangle connection, counterclockwise (L1, L3, L2); If U1 / W2, V1 / U2, and W1 / V2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 120°, it is determined as: triangle connection, clockwise (L1, L2, L3); If U1 / W2, V1 / U2, and W1 / V2 are connected in pairs, and the phase angle between the three terminals of U1 / V1 / W1 is about 240°, then it is determined as: triangle connection, counterclockwise (L1, L3, L2); Others are judged as incorrect wiring methods.

9. The method for simulating parameter changes of a three-phase asynchronous motor according to claim 8, characterized in that: The rotation speed is calculated based on the wiring method and the effective period. The speed is inversely proportional to the effective period.

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