I. Overview of experimental devices for power electronics
"JGDD-1 Motor Speed Control Technology Experimental Device" is based on the latest unified textbook "Power Electronics Technology" (Fourth Edition) (edited by Wang Zhaoan of Xi'an Jiaotong University) and "Automatic Control System for Electric Drive" (third Version) (edited by Chen Boshi of Shanghai University) and other experimental outlines, absorbing the advantages of similar products at home and abroad, fully considering the current situation and development trend of the laboratory, carefully developed. It has reasonable structure, perfect functions, good reliability and high cost performance among similar products.
Second, the characteristics of power electronics technology experimental device
1. Comprehensive and comprehensive This device integrates various experimental projects of power electronics, semiconductor converters, AC and DC speed regulation, AC frequency conversion, motor control, and control theory in various schools in China.
2. Strong adaptability can meet the experimental teaching of corresponding courses in various schools. The depth and breadth can be flexibly adjusted according to needs, and the popularization and improvement can be organically combined according to the teaching process. The device adopts a building block structure, which is convenient to replace if necessary. Extend functions or develop new experiments, just add components and never get rid of them.
3. The complete set is complete from the dedicated power supply, motor and other experimental components to the dedicated connection for the experimental connection. The performance and specifications of the supporting components are closely combined with the needs of the experiment.
4. Intuitive. Each experimental pendant adopts a separated structure. The component panel is schematic and the figure is clear. The tasks of each pendant are clear, and the operation and maintenance are convenient.
5.Scientific equipment has a small footprint, saves experimental rooms, and reduces infrastructure investment; the supporting small motors are specially designed to simulate the characteristics and parameters of small and medium-sized motors; small motors consume less power, save energy, and experiment noise It is small, neat and beautiful, and improves the experimental environment; the experiment is rich in content and the design is reasonable. In addition to deepening the theoretical knowledge, it can also be combined with the actual situation to design experiments.
6. The power supply of the open control panel is isolated by a three-phase isolation transformer, and is equipped with a voltage leakage protection device and a current leakage protection device to ensure the safety of the operator; each power output has functions such as monitoring and short circuit protection. The measuring instruments have reliable protection functions and are safe and reliable to use. The control screen is also provided with a timer and alarm recorder, which provides a unified standard for the assessment of students' experimental skills. Due to the careful design of the entire device, coupled with reliable component quality and reliable technology as the guarantee, the product performance is excellent. All these are open laboratories, creating conditions.
7. Advanced. This device focuses on the consideration of new devices. On the basis of retaining the thyristor experiment, it adds the characteristics of new devices, the driving of new devices, and a large number of modern power electronics technology experiments for typical new device applications. Have enough knowledge and understanding of new devices to keep up with the times.
3. Applicable scope of power electronic motor control technology experimental device This device covers "power electronic technology (or semiconductor converter technology)", "DC speed regulation", "AC speed regulation", " Experimental items required by professional courses such as "motor control", "electric drag automatic control system" and "control theory".
Fourth, the technical performance of power electronics technology experimental device
1.Input power: Three-phase four-wire (or three-phase five-wire 380V ± 10% 50HZ)
2. Working environment: Temperature -10 ℃-+40 ℃ Relative humidity <85% (25 ℃) Altitude <4000m
3. Device capacity: <1.5KVA
4. Dimensions: 187.3 × 75 × 162.2 cm3
V. Basic equipment of power electronics technology experimental device
1. DJK01 power control screen (iron double-layer matte dense grain spray-painted structure, acrylic panel)
(1) AC power supply (both with overcurrent protection measures)
Provide AC power: DC speed control gear is three-phase AC 200V / 3A
AC speed adjustment is three-phase AC 240V / 3A
(2) High-voltage DC power source: 220V (0.5A), with output short circuit protection.
(3) Digital instrument
1 . AC digital voltmeter: It can indicate the input line voltage of the three-phase power grid through the band switch below it, with an accuracy of 1.0;
2 . A true RMS AC digital voltmeter: measuring range 0 to 500V, automatic range judgment and automatic switching, accuracy class 0.5, three and a half digital display, providing voltage indication for AC speed regulation system;
3． A true RMS AC digital ammeter: measuring range 0 to 5A, automatic range judgment, automatic switching, accuracy level 0.5, three and a half digital display, with over-range alarm, indication and cut off the total power supply function, providing current for the speed control system Instructions
4. One DC digital voltmeter: measuring range 0 to 300V, three and a half digital display, input impedance 10M Ω, accuracy class 0.5, providing voltage indication for reversible speed regulation system;
5. One DC digital ammeter: measuring range is 0 to 5A, three and a half digital display, accuracy level 0.5, with functions such as over-range alarm, indication, cut off the total power, etc., to provide current indication for reversible speed regulation system.
(4) Personal safety protection system: A set of three-phase isolation transformers: Three-phase power first passes the three-phase leakage protector, and then passes the key switch and contactor to the isolation transformer to isolate the output from the power grid (floating design), which is personally safe. Play a certain protective role.
Voltage type leakage protector 1: Protects the leakage phenomenon of the line in front of the isolation transformer, trips the contactor in the control screen, and cuts off the power.
Voltage type leakage protector 2: Protects the leakage phenomenon of the line after the isolation transformer and the wiring during the experiment, sends an alarm signal and cuts off the power to ensure personal safety.
Current leakage protection device: If there is leakage in the control panel and the leakage current exceeds a certain value, the power will be cut off.
Experimental connection cables and sockets: Strong and weak electrical connections and sockets should be separated and not mixed. Strong electric connection cables and sockets are fully enclosed, which is safe, reliable and resistant to electric shock.
(5) The experiment manager has the functions of setting the experiment time, timing alarm, cutting off the power, etc .; it can also automatically record and distinguish the leakage alarm and the instrument over-range alarm caused by wiring or operation errors.
(6) Control panel Other facilities The control panel is equipped with two stainless steel tubes in a large groove on the front of the control panel, which can be used for hanging experimental components. The bottom of the groove is provided with 12-core, 10-core, 4-core, 3-core and other sockets. Provided by these sockets. There are single-phase three-pole 220V power sockets and three-phase four-pole 380V power sockets on both sides of the control screen. There is also a 40W fluorescent lamp for experimental bench lighting.
2. DJK02 experimental table The experimental table is an iron double-layer matte dense grain spray-painted structure. The table top is a fire-resistant, waterproof, wear-resistant high-density board. The structure is sturdy. Large drawers and cabinet doors for tools, storage of pendants and materials. The table top is used to install a power control screen and provides a spacious and comfortable work surface. The experimental table is also provided with four universal wheels and four fixed adjustment mechanisms, which are convenient to move and fix, which is beneficial to the layout of the laboratory.
3, DQ03 － 1 stainless steel motor guide, optical code disc speed measurement system and digital tachometer
4. DQ27 three-phase adjustable resistance (900 Ω × 2 / 0.41A per group)
5. The DJK03 thyristor main circuit provides 12 5A / 1000V thyristors, divided into two groups: positive and reverse bridges. Each thyristor is equipped with a protection device. The positive and reverse bridge thyristors can be triggered by external signals (the trigger pulse input interface is left). ), Can better complete the design experiments; equipped with mirror precision pointer DC voltage meter ± 300V, accuracy class 1.0 with mirror DC current meter ± 2A, accuracy class 1.0 each of a group of flat wave reactors.
6, DJK04 three-phase thyristor trigger circuit provides three-phase trigger circuit, power amplifier circuit, etc., used in conjunction with "DJK03".
7. DJK05 Thyristor trigger circuit experiment provides five types of trigger circuits: single junction transistor trigger circuit, sine wave synchronous phase shift trigger circuit, sawtooth wave synchronous phase shift trigger circuit, single phase AC voltage regulation trigger circuit and single phase parallel inverter trigger circuit .
8. DJK06 motor speed control experiment (Ⅰ)
Provide the following modules: current feedback and over-current protection (FBC + FA), setter (G), speed converter (FBS), speed regulator (ASR), inverter (AR), current regulator (ACR) , Torque Polarity Identification (DPT), Zero Level Detection (DPZ), and Logic Controller (DLC).
9. DJK07 DC chopper circuit is mainly composed of chopper trigger circuit and chopper main circuit.
10. DJK08 given and experimental devices provide given (± 15V adjustable voltage output), varistor (as an overvoltage protection element, which has been connected internally in a delta connection), diode, 24V power supply and inductor.
11. DJK09 new device characteristic experiment Provides new devices such as SCR, MOSFET, IGBT, GTO, GTR. It can be used with DJK06 to measure its characteristic curve. When used with DJK12, it can complete the drive characteristic experiment of new power electronics devices.
12. DJK10 adjustable resistors and capacitor boxes provide three sets of adjustable capacitors with a withstand voltage of AC63V. The adjustable range is 0.1 to 11.37uF, and two sets of 0 to 999K Ω decimal adjustable resistors.
13. DJK11 single-phase voltage regulation and adjustable load provides a 0 ～ 250V / 0.5KVA single-phase AC auto-coupled voltage regulator to provide adjustable power for corresponding experiments; a rectifier filter circuit and 0 ～ 90 Ω / 1.3 A (series) or 0 to 45 Ω /2.6A (parallel) ceramic plate adjustable resistance, which provides an adjustable resistive load for corresponding experiments.
14, DJK12 transformer experiment provides a three-phase core type transformer (the transformer has 2 sets of secondary windings, the voltage of the primary and secondary windings is 127V / 63.6V / 31.8V), used for asynchronous motor cascade speed regulation experiments and three Phase bridge type, single phase bridge type active inverter circuit experiment; three sets of three-phase uncontrolled rectifier circuit and inverter transformer are also provided.
15. DJK13 power device driving circuit experiment box is mainly to provide driving and protection circuits for the completion of new device characteristic experiments, so that students understand the driving characteristics of new power electronics devices. It mainly includes power supply, driving circuit and PWM waveform generator.
(1) Power supply: Provide power for the drive circuit, including ± 5V, + 20V, ± 15V DC power.
(2) Drive circuit: Drive circuit including MOSFET, IGBT, GTR and GTO. Among them, the IGBT driving circuit uses a special chip EXB841.
(3) PWM waveform generator: The PWM waveform generator with SG3525 as the core mainly provides the PWM driving waveform for the new device driving circuit; the frequency can be adjusted by the frequency adjustment knob; the duty cycle of the PWM wave can be adjusted by the duty potentiometer The frequency range is divided into 2 levels, which can be switched by a toggle switch. The high-frequency range is to provide PWM waveforms for the MOSFET and IGBT drive circuits, and the frequency adjustment range is 4KHz to 10KHz. The low-frequency range is to provide PWM waveforms for the GTR and GTO drive circuits. The adjusting range is 400Hz to 1KHz; the duty cycle can be adjusted from 0% to 100%.
16. DJK14 Single-phase AC-DC inverter principle is developed based on the national key textbook of the "Ninth Five-Year Plan" for general higher education, and related content of "Power Electronics Technology" (Fourth Edition) edited by Wang Zhao'an and Huang Jun. It is used to demonstrate AC-DC AC inverter The principle is mainly for students to understand the formation method of SPWM sine wave pulse width modulation signal, and to understand the characteristics and use of integrated driving chip for IGBT tube. It can complete the following experimental items: 1. The process of SPWM wave formation; 2. The working conditions and waveforms of AC-DC-AC frequency conversion circuits under different loads (resistance, inductance and motor), and study the impact of working frequency on the working waveform of the circuit; 3, Operating characteristics of IGBT integrated driving chip.
17. DJK15 self-control principle experiment provides regulated power supply, AC / DC digital voltmeter, low-frequency function signal generator, six-digit display frequency meter, step signal generator and typical control links (proportion link, inertia link, integration link) , Advanced lag correction link, can also form a variety of circuits such as differentiation, delay, etc.).
18, DJK16 automatic control principle experiment provides regulated power supply, step signal generator, typical control links (proportion link, inertia link, integral link, lead lag correction link, and can also form differential, delay and other circuits) and free wiring Zone (for freely combining experimental lines for experiments)
19. DJK17 dual closed-loop H-bridge DC / DC conversion DC speed control system achieves the purpose of speed regulation of reversible DC separately-excited motors by triggering control of IGBT tubes on four bridge arms, which is mainly composed of three parts, namely Main circuit part, control circuit part and adjustment part. The main circuit is composed of DC power supply and four IGBT tubes. The control circuit is composed of a dedicated chip to generate PWM pulse waves. The four control pulses generated by the PWM wave pulse generator drive the IGBT tubes of the four bridge arms respectively. The regulating part is composed of two It consists of a PI regulator, and the speed of the motor runs stably at a given speed through a feedback loop composed of a speed loop and a current loop. The experimental items that can be completed in this experiment box are: (1), full-bridge DC / DC conversion circuit experiment (2), double closed-loop reversible DC pulse width speed regulation experiment.
20 、 DJK18 motor speed control experiment (Ⅱ)
The following modules are provided: trigger selector (TS), absolute value amplifier (GAB), current sign selector (CSS), voltage regulator (AVR), zero speed blocker (DZS), and voltage isolator (TVD). Used in conjunction with "DJK06" to complete the "three closed-loop dislocation selective contactless circulating reversible DC speed control system experiment".
21. DJK19 half-bridge switching regulator power supply provides the main circuit and control circuit of the half-bridge switching regulator power supply. The power electronic devices in the main circuit are power MOSFET tubes; the control circuit uses a dedicated PWM control integrated circuit SG3525, which uses constant Frequency pulse width modulation control scheme. It can complete the experimental content of "test of load characteristics of switch circuit under open loop and closed loop" and "effect of power supply voltage fluctuation on output".
22. DJK20 DC chopper experiment is designed according to the relevant DC chopper content in Power Electronics Technology (Fourth Edition) edited by Professor Wang Zhaoan and Professor Huang Jun of Xi'an Jiaotong University; it provides the necessary components to form a DC chopper circuit. The device and the dedicated PWM control integrated circuit SG3525. Can complete buck chopper circuit, boost chopper circuit, boost-buck chopper circuit, cuk chopper circuit, sepic chopper circuit, zeta chopper in teaching materials Six typical experiments of circuits.
23. DJK21 chopped AC voltage regulator circuit is designed based on the relevant content in Power Electronics Technology (Fourth Edition) edited by Professor Wang Zhaoan and Professor Huang Jun of Xi'an Jiaotong University. AC voltage regulation experiment. "
24. DJK22 single-phase voltage regulation / power regulation circuit is designed according to the relevant content edited by Professor Wang Zhao'an and Professor Huang Jun of Xi'an Jiaotong University to realize the experimental content of single-phase AC voltage regulation and AC power regulation. The power electronic device used is a bidirectional thyristor. In the AC voltage regulation experiment, a bidirectional trigger diode is used to form the trigger control circuit; in the AC power regulation experiment, a 555 time base circuit is used to form the trigger control circuit.
25. DJK23 single-ended flyback switch power supply with input AC voltage range of 50V ~ 200V, output is three sets of DC power supply, respectively + 5V, 5A; + 12V, 1A; -12V, 1A, at the input AC voltage and DC The rate of change of output voltage when the output load changes is less than 0.3%.
26. DJK24 PS-ZVS-PWM soft switching technology mainly includes H-bridge circuit, control circuit and voltage feedback circuit. Used to show the circuit structure and working principle of phase-shifted zero-voltage switch. The H-bridge circuit is composed of four MOSFET tubes. The control circuit uses a full-bridge soft-switching power supply phase-shifted PWM control chip UCC3895 and a driver chip HIP4081. The voltage-stabilizing feedback circuit is composed of TL431 and other components.
27. DJK25 rectifier circuit active power factor correction mainly consists of rectifier circuit, boost converter and control circuit. The control circuit is composed of a power factor control chip UCC3817N and peripheral components. The maximum output power is 100W (200V ± 5%, 0.5A), and the operating frequency is 100KHz. With modular design, the following experimental items can be completed through proper wiring:
(1) Test of rectifier circuit without filter capacitor with pure resistive load
(2) Test of rectifier circuit with filter capacitor with pure resistive load
(3) Test of active power factor correction of rectifier circuit
(4) Waveform test of control circuit, observation of power grid control signal
(5) Performance test of rectifier circuit active power factor correction circuit
28. DJK26 single-ended current feedback separate-excitation isolated switching power supply adopts special integrated circuit SG3525 as PWM controller, which can directly drive MOSFET power field effect transistor. By cooperating with a DC adjustable power supply and a load, the circuit principle, waveform test at each point, waveform change and performance test when the input voltage and load are changed can be displayed.
29. DJK27 The step-up, step-down and compound chopper circuit is simply connected with two IGBT transistors and two diodes through the PWM controller, combined with the combined load of the generator and the motor. The dual-trace oscilloscope can be used to show the first step of the step-down circuit. One quadrant voltage-current graph, the second quadrant voltage-current graph of the boost circuit, and the first and second quadrant voltage-current graphs of the composite circuit. At the same time, it can display the freewheeling, critical cutoff, voltage and current waveforms (changing the input voltage, changing the PWM pulse width, and changing the load motor torque) in the above three states. And it can be simply connected to step-up, step-down and composite circuits. Due to the structural characteristics, the experiment can also demonstrate the experimental effects of load chopper circuit motor load braking, feedback braking and so on.
30. DJK28 Three-phase asynchronous motor variable frequency speed control For current industrial inverters, only the input signals and output results can be observed, and the shortcomings of the detailed internal working process cannot be known. The experimental device was developed, focusing on the "frequency conversion "Principle", through experiments to let students understand the entire frequency conversion process.
Provide three-phase sine wave pulse-width modulation (SPWM), saddle wave (PWM), three-phase space voltage vector pulse-width modulation (SVPWM) three frequency conversion experimental methods, corresponding test points on the panel, which can be conveniently performed with an oscilloscope Observe. In addition, a computer interface is designed on the panel, which can be connected to a computer for experiments, and a programmable controller (PLC) interface is also reserved.
31. DJK29 single-phase intelligent power and power factor meter is designed by a 24-bit dedicated DSP, a 16-bit high-precision AD converter and a high-speed MPU unit. The key-control and digital display windows are used to realize the man-machine dialogue function control mode. The software adopts RTOS design ideas, and is equipped with PC monitoring software to strengthen analysis capabilities. Can measure the power and power factor of the circuit. The power measurement accuracy is 1.0 level, the power factor measurement range is 0.3-1.0, the voltage and current ranges are 450V and 5A, and the load characteristics can be automatically determined (inductive display "L", capacitive display "C", pure resistance is not displayed), and Store measurement data for review at any time.
32 、 DQ07-1 DC generator (220W)
33 、 DQ09 DC Parallel Excitation Motor
34 、 DQ11 three-phase wire-wound asynchronous motor
35 、 DJK30 special box for rotor of wire-wound asynchronous motor
36, DQ17 single-phase resistance start asynchronous motor
37 、 DQ20 three-phase squirrel cage asynchronous motor
38. Experimental connection line: According to the characteristics of different experimental items, it is equipped with two different experimental connection lines. The high-power part uses a highly reliable sheathed structure pistol connection line (there is no possibility of electric shock), which uses oxygen-free copper extraction. Multi-stranded wires with silk-like hair are ultra-soft. The outer layer is made of butadiene polyvinyl chloride. It has the advantages of softness, high pressure resistance, high strength, hardening resistance and good toughness. The plug is made of solid copper. One piece of beryllium light copper shrapnel, contact is safe and reliable; the weak current part uses the elastic beryllium light copper bare structure connection wire, and both types of wires can only cooperate with the corresponding inner hole socket, which greatly improves the safety and rationality of the experiment.
6. Experimental items that can be set up by this power electronics technology experimental device (when all the equipment listed are configured)
(I) Power Electronics Technology Experimental Project
1 . Single junction transistor trigger circuit
2 . Experiment of sine wave synchronous phase shift trigger circuit
3． Experiment of Sawtooth Synchronous Phase-shift Trigger Circuit
4. Experiment of single-phase half-wave controllable rectifier circuit
5. Experiment of single-phase bridge half-controlled rectifier circuit
6. Single-phase bridge full-control rectification and active inverter circuit experiment
7. Experiment of three-phase half-wave controllable rectifier circuit
8 . Experiment of three-phase bridge half-controlled rectifier circuit
9 . Experiment of three-phase half-wave active inverter circuit
10. Three-phase bridge full-control rectification and active inverter circuit experiment
11. Single-phase parallel inverter circuit experiment
12. Single-phase AC voltage regulator circuit experiment
13. Single-phase AC power regulation circuit experiment
14． Three-phase AC voltage regulating circuit experiment
15. DC chopper circuit principle experiment
16. Characteristic experiment of unidirectional thyristor (SCR)
17. Turn-off thyristor (GTO) characteristic experiment
18. Power field effect transistor (MOSFET) characteristics experiment
19. Power transistor (GTR) characteristic experiment
20. Characteristic experiment of insulated bipolar transistor (IGBT)
twenty one . Experiment of Turn-Off Thyristor (GTO) Drive and Protection Circuit
twenty two . Experiment of power MOSFET driving and protection circuit
twenty three . Experiment of Power Transistor (GTR) Drive and Protection Circuit
twenty four . Experiment of Insulated Bipolar Transistor (IGBT) Drive and Protection Circuit (2) Typical Power Electronic Device Circuit Experiment
1 . Experiment of single-phase sine wave pulse width modulation (SPWM) inverter circuit
2 . Full-bridge DC / DC converter circuit experiment
3． Research on the performance of half-bridge switching regulated power supply
4. Experiment of single-ended flyback isolated switching power supply
5. Experiment of single-ended current-feedback separately excited switching power supply
6. Research on the performance of DC chopper circuit (buck chopper circuit, boost chopper circuit, buck-boost chopper circuit, cuk chopper circuit, Sepic chopper circuit, Zeta chopper circuit)
7. Boost, Buck and Compound Chopper Circuit Experiment
8 . Single-phase chopped AC voltage regulator circuit experiment
9 . Experiment on Active Power Factor Correction of Rectifier Circuit
10. Soft switching technology experiment (3) DC motor speed regulation experiment
1 . Measurement experiment of parameters and link characteristics of thyristor DC speed control system
2 . Debugging of Main Units of Thyristor DC Speed Control System
3． Experiment of single closed-loop irreversible DC speed regulating system
4. Experiment of double closed loop irreversible DC speed regulating system
5. Experiment of Logic Acyclic Reversible DC Speed Control System
6. Experiment of Three Closed-loop Displacement-selective Contactless Circulating Reversible DC Speed-regulating System
7. Double closed-loop controlled DC pulse width speed regulation system (H-bridge, IGBT)
(Four) frequency conversion principle experiment
1 . Three-phase sine wave pulse width modulation (SPWM) frequency conversion principle experiment
2 . Three-phase saddle wave (third harmonic injection) pulse width modulation frequency conversion principle experiment
3． Three-phase space voltage vector SVPWM frequency conversion principle experiment
4. V / F curve measurement under SPWM modulation
5. Measurement of V / F curve under saddle wave modulation
6. Measurement of V / F curve under space voltage vector modulation
7. Observation experiment of magnetic flux trajectory under different frequency conversion modes (5) Experiment of AC motor speed control system
1 . Experiment on voltage and speed regulation system of double closed-loop three-phase asynchronous motor
2 . Experiment of double closed-loop three-phase asynchronous motor series pole speed control system
3． Single-phase sine wave pulse width modulation SPWM variable frequency speed regulation system experiment
4. Three-phase sine wave pulse width modulation (SPWM) frequency conversion speed regulation system experiment-can be connected to a computer for experiments, but also has a programmable controller (PLC) interface
5. Three-phase saddle-wave pulse-width modulation and variable-frequency speed-adjusting system experiment-can be connected to a computer for experiments, and a programmable controller (PLC) interface is left
6. Three-phase space voltage vector SVPWM variable frequency speed regulation system experiment-can be connected to a computer for experiments, and also has a programmable controller (PLC) interface
(6) Experimental project of automatic control principle
1 . Simulation of typical links of control system
2 . Time domain response and parameter determination of first-order system
3． Transient response analysis of second-order systems
4. Transient Response and Stability Analysis of Third-Order System
5. Dynamic Performance of PID Controller
6. Dynamic correction of control system
7. Test of frequency characteristics of typical links
8 . Testing of frequency characteristics of linear systems
9 . Signal sampling and recovery
10. Simulation of typical nonlinear links
11. Phase Plane Analysis of Nonlinear Systems
7. Detailed configuration and price of the experimental device for motor speed regulation technology: (***** / sets) (experimental module can be optional)
Power control screen
Stainless steel motor guide, motor, optical code disc speed measurement system and digital display tachometer
Three-phase adjustable resistance (900 Ω * 2 / 0.41A per group)
Three-phase thyristor main circuit
Thyristor trigger circuit
Motor speed control experiment (Ⅰ)
Given and experimental devices
Single-phase voltage regulation and adjustable load
Compound excitation DC generator
DC Parallel Excitation Motor
Single-phase resistance start asynchronous motor
Three-phase squirrel-cage asynchronous motor
Safety type stacking pistol type protective sleeve experimental connecting line and accessories
(Experimental module can be optional)