Miniature teaching equipment for power system

Abstract

The utility model discloses a miniature teaching device for an electric power system, which comprises a first direct-current power supply and a second direct-current power supply, the output ends of the first direct-current power supply and the second direct-current power supply are connected with a direct-current motor, the direct-current motor is connected with a direct-current generator, and the direct-current generator and the second direct-current power supply are connected with an energy storage capacitor in parallel; the energy storage capacitor is connected to the input end of the inverter circuit, the inverter circuit is connected with a power transmission unit, the power transmission unit is connected with a power distribution unit through a power transmission network, and the power distribution unit is connected with a power utilization unit. According to the utility model, the operation process and each link function of the power system can be intuitively and deeply understood, the complexity of power grid operation and the optimization strategy thereof can be learned by simulating the fault scene in the actual power grid, and the understanding of the dynamic characteristics of the power system is enhanced.

Description

TECHNICAL FIELD

[0001] The utility model belongs to the technical field of electric power teaching equipment, specifically relates to electric power system micro teaching equipment. BACKGROUND

[0002] Power conversion technology plays a crucial role in integrating renewable energy, ensuring grid stability, improving energy efficiency, ensuring device compatibility, promoting the development of smart grids, and addressing climate change. In the field of modern education, especially in the teaching of engineering technology and power electronics, the intuitive display and experimental operation of the power conversion process are of great significance. The current market has limited types of electric power system teaching aids, and there is still a lack of a comprehensive and realistic micro power system model. Moreover, traditional power conversion teaching equipment often has some shortcomings, mainly in the following aspects: first, structural complexity; traditional teaching equipment is often composed of multiple independent components, which need complex connection and debugging between components, making the installation and operation process of the whole system cumbersome, which increases the teaching cost. Secondly, cost problem; due to the use of high-quality materials and precise manufacturing process in traditional equipment, the cost is relatively high, which limits the investment of schools and educational institutions in teaching resources, especially in the case of limited resources, the high cost makes it impractical to popularize power conversion teaching equipment. Thirdly, teaching effect; due to the complexity of structure and high cost, students often lack the opportunity to operate, which limits their intuitive understanding and practical skills in power conversion process, and it is difficult to understand the conversion of direct current to alternating current, voltage conversion and other power conversion processes through observation and operation. SUMMARY

[0003] The utility model discloses an electric power system micro teaching equipment, which solves the problem of complex structure of the prior art power conversion teaching equipment.

[0004] The utility model discloses the technical scheme adopted is: electric power system micro teaching equipment, including first direct current power supply and second direct current power supply, first direct current power supply, the output end of first direct current power supply is connected with direct current motor, direct current motor is connected with direct current generator, and direct current generator is connected with energy storage capacitor in parallel with second direct current power supply.

[0005] Still include inverter circuit, energy storage capacitor is connected in the input end of inverter circuit, and inverter circuit is connected with power transmission unit, and power transmission unit is connected with distribution unit through power transmission network, and distribution unit is connected with power unit.

[0006] The utility model discloses the technical scheme adopted is:

[0007] The rotor of the direct current motor is provided with a magnet, the direct current motor is connected with the rotor of the direct current generator through a belt, the direct current motor is provided with a Hall sensor, the Hall sensor is arranged close to the rotor of the direct current generator, and the output end of the direct current generator is provided with a voltage sensor.

[0008] The inverter circuit is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor, and the LC filter circuit is connected between the inverter circuit and the power transmission unit.

[0009] The power transmission unit comprises three single-phase step-up transformers, the three-phase output end of the inverter circuit is connected with the input end of the three single-phase step-up transformers through a three-phase four-wire connection mode, and the three single-phase step-up transformers are connected through a delta connection mode.

[0010] The power distribution unit comprises three single-phase step-down transformers, and the three single-phase step-down transformers are connected with the single-phase step-up transformers through a power transmission network respectively.

[0011] The power utilization unit comprises a three-phase asynchronous motor, each winding of the three-phase asynchronous motor is connected between two phase lines of the single-phase step-down transformer, the three-phase asynchronous motor is provided with a mechanical switch, three-phase power sources are connected to the input end of the mechanical switch respectively, and the output end of the mechanical switch is connected to the three-phase winding of the three-phase asynchronous motor.

[0012] The power utilization unit further comprises a resistance heater, one end of the resistance heater is connected to one phase line of any single-phase step-down transformer, the other end of the resistance heater is connected to a neutral line in the three-phase four-wire, the resistance heater is provided with a solid-state relay, the input end of the solid-state relay is connected with the output end of the inverter circuit, and the output end of the solid-state relay is connected with the resistance heater.

[0013] The power utilization unit further comprises a direct current motor, the direct current motor is connected with a rectification filter module, and the rectification filter module is connected with the three-phase asynchronous motor.

[0014] The power system micro teaching equipment provides an intuitive learning platform, the structure is simple and integrated, so that students can intuitively and deeply understand the operation process and the function of each link of the power system, learn the complexity of the power grid operation and the optimization strategy through simulating the fault scene in the actual power grid, and enhance the understanding of the dynamic characteristics of the power system; the power system core functions are covered, including power generation, power transmission, power transformation, power distribution and power utilization, comprehensive practical content is provided for teaching, the model supports simulation of various power utilization scenes, helps to display the whole process of power grid operation visualization and typical faults in the power system operation process, such as single-phase grounding fault, three-phase load imbalance, and power generation power and power consumption power mismatch, and the interactivity and practicality of teaching are improved. BRIEF DESCRIPTION OF DRAWINGS

[0015] Fig. 1 is a structural schematic diagram of the power system microteaching equipment of the utility model;

[0016] Fig. 2 is a structural principle diagram of the power system microteaching equipment of the utility model.

[0017] In the figure, 1. first DC power supply, 2. DC motor, 3. DC generator, 4. inverter circuit, 5. power transmission unit, 6. power transmission network, 7. power distribution unit, 8. rectifier filter module, 9. second DC power supply, 10. energy storage capacitor. DETAILED DESCRIPTION

[0018] The utility model will be explained in detail below in combination with the drawings and specific embodiments.

[0019] The utility model provides power system microteaching equipment, such as Figs. 1-2 As shown, including first DC power supply 1 and second DC power supply 9, first DC power supply 1, the output end of first DC power supply 1 is connected with DC motor 2, DC motor 2 is connected with DC generator 3, and DC generator 3 is connected with energy storage capacitor 10 in parallel with second DC power supply 9;Still including inverter circuit 4, energy storage capacitor 10 is connected at the input end of inverter circuit 4, and inverter circuit 4 is connected with power transmission unit 5, and power transmission unit 5 is connected with power distribution unit 7 through power transmission network 6, and power distribution unit 7 is connected with power unit. First DC power supply 1, second DC power supply 9, DC motor 2, DC generator 3 and energy storage capacitor 10 all belong to power generation unit, first DC power supply 1 is as main power module, and the overvoltage protection (OVP) function is enabled or closed through " OVSET " key, when OVP function is enabled, if the output voltage exceeds the set " OVSET " value, the power supply will automatically cut off the output to protect the circuit, first DC power supply is connected at the input end of DC motor 2, simulates the basic operation process of wind turbine generator, is used for simulating wind power generation, and can provide initial DC electric energy for the system, DC motor 2 is as power drive module, DC generator 3 is as DC power module, is coupled with DC motor 2 through belt drive, and converts mechanical energy into electric energy, inverter circuit 4 is as power transformation unit, converts DC into three-phase AC, and is connected with each sensor, and the key parameters of power grid and the related parameters of energy storage capacitor are displayed in real time, power transmission unit 5 is boost module, and is connected with power transformation unit through wire and promotes three-phase AC after inversion to 220V, power transmission network 6 adopts three-phase four-wire system, is responsible for transmitting high-voltage three-phase AC to power distribution unit, power distribution unit 7 adopts three-phase four-wire system, is responsible for transmitting high-voltage three-phase AC to power distribution unit, second DC power supply 9 is as standby power supply, is used for simulating the peak shaving power supply in power system, provides additional electric energy during the power consumption peak, to compensate for the power consumption gap, energy storage capacitor 10 integrates temperature sensor, and is connected with the microcontroller of inverter circuit 4 through serial communication port.

[0020] Embodiment 1

[0021] The power system microteaching device comprises a first DC power supply 1 and a second DC power supply 9, the first DC power supply 1, the output end of the first DC power supply 1 is connected with a DC motor 2, the DC motor 2 is connected with a DC generator 3, the DC generator 3 is connected in parallel with the second DC power supply 9 and has an energy storage capacitor 10; further comprising an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power consumption unit.

[0022] The rotor of the DC motor 2 is provided with a magnet, the DC motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the DC motor 2, and the Hall sensor is connected with the inverter circuit 4 through a serial communication port, the real-time rotation speed data is transmitted and monitored, and the output end of the DC generator 3 is connected with a voltage sensor and connected with a microcontroller of the inverter circuit 4 through a serial communication port, and the output voltage is collected in real time.

[0023] Embodiment 2

[0024] The power system microteaching device comprises a first DC power supply 1 and a second DC power supply 9, the first DC power supply 1, the output end of the first DC power supply 1 is connected with a DC motor 2, the DC motor 2 is connected with a DC generator 3, the DC generator 3 is connected in parallel with the second DC power supply 9 and has an energy storage capacitor 10; further comprising an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power consumption unit.

[0025] The rotor of the DC motor 2 is provided with a magnet, the DC motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the DC motor 2, and the Hall sensor is connected with the inverter circuit 4 through a serial communication port, the real-time rotation speed data is transmitted and monitored, and the output end of the DC generator 3 is connected with a voltage sensor and connected with a microcontroller of the inverter circuit 4 through a serial communication port, and the output voltage is collected in real time.

[0026] The inverter circuit 4 is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor 10, and the LC filter circuit is connected between the inverter circuit 4 and the power transmission unit 5. The inverter circuit 4 adopts an STM32F103 chip as a microcontroller, the STM32F103 microcontroller is used as a control monitoring unit of the device, and real-time collection of various key parameters and control of the energy storage unit are realized; the inverter circuit 4 converts the direct current generated by the second direct current power supply 9 and the direct current generator 3 into a three-phase SPWM wave through a sine pulse width modulation (SPWM) technology, and then the direct current is converted into a power frequency sine alternating current through LC filtering, and the output of the inverter circuit 4 adopts a three-phase four-wire system, and the output circuit includes an LC filter to reduce harmonics and electromagnetic interference, and also includes overload and short circuit protection to ensure the safety of the system.

[0027] Embodiment 3

[0028] The power system microteaching device comprises a first direct current power supply 1 and a second direct current power supply 9, the output end of the first direct current power supply 1 is connected with a direct current motor 2, the direct current motor 2 is connected with a direct current generator 3, and the direct current generator 3 is connected in parallel with the energy storage capacitor 10; the device further comprises an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power consumption unit.

[0029] The rotor of the direct current motor 2 is provided with a magnet, the direct current motor 2 is connected with the rotor of the direct current generator 3 through a belt, the direct current motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the direct current generator 2, and the output end of the direct current generator 3 is connected with a voltage sensor.

[0030] The inverter circuit 4 is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor 10, and the LC filter circuit is connected between the inverter circuit 4 and the power transmission unit 5.

[0031] The power transmission unit comprises three single-phase step-up transformers, the three-phase output end of the inverter circuit 4 is connected with the input end of the three single-phase step-up transformers in a three-phase four-wire system connection mode, and the three single-phase step-up transformers are connected in a delta connection mode. The single-phase step-up transformer is of a DB-50W type, the single-phase step-up transformer adopts a delta connection mode, a neutral line is led out from a neutral point, a three-phase four-wire system power transmission network structure is formed, low-voltage three-phase alternating current is stepped up to high-voltage three-phase alternating current meeting the requirements of a power grid, and long-distance power transmission and reasonable distribution of electric energy are realized. The power transmission unit is designed to simulate a high-voltage power transmission link in a real power grid, and low-voltage three-phase alternating current is stepped up to 220V three-phase alternating current of the power grid.

[0032] Embodiment 4

[0033] The power system microteaching device comprises a first DC power supply 1 and a second DC power supply 9, the output end of the first DC power supply 1 is connected with a DC motor 2, the DC motor 2 is connected with a DC generator 3, the DC generator 3 is connected in parallel with the second DC power supply 9 and has an energy storage capacitor 10; the device further comprises an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power consumption unit.

[0034] The rotor of the DC motor 2 is provided with a magnet, the DC motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the DC motor 2, and the output end of the DC generator 3 is connected with a voltage sensor.

[0035] The inverter circuit 4 is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor 10, and the inverter circuit 4 is connected with an LC filter circuit and the power transmission unit 5.

[0036] The power transmission unit comprises three single-phase step-up transformers, the three-phase output end of the inverter circuit 4 is connected with the input end of the three single-phase step-up transformers through a three-phase four-wire connection mode, and the three single-phase step-up transformers are connected through a delta connection mode.

[0037] The power distribution unit comprises three single-phase step-down transformers, and the three single-phase step-down transformers are connected with the single-phase step-up transformers through the power transmission network 6. The power distribution unit further reduces high-voltage electric energy to a low-voltage level suitable for end users.

[0038] Embodiment 5

[0039] The power system microteaching device comprises a first DC power supply 1 and a second DC power supply 9, the output end of the first DC power supply 1 is connected with a DC motor 2, the DC motor 2 is connected with a DC generator 3, the DC generator 3 is connected in parallel with the second DC power supply 9 and has an energy storage capacitor 10; the device further comprises an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power consumption unit.

[0040] The rotor of the DC motor 2 is provided with a magnet, the DC motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the DC motor 2, and the output end of the DC generator 3 is connected with a voltage sensor.

[0041] The inverter circuit 4 is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor 10, and the LC filter circuit is connected between the inverter circuit 4 and the power transmission unit 5.

[0042] The power transmission unit includes three single-phase step-up transformers, the three-phase output end of the inverter circuit 4 is connected with the input end of the three single-phase step-up transformers through a three-phase four-wire connection mode, and the three single-phase step-up transformers are connected through a delta connection mode.

[0043] The power distribution unit includes three single-phase step-down transformers, and the three single-phase step-down transformers are respectively connected with the single-phase step-up transformers through the power transmission network 6.

[0044] The power utilization unit includes a three-phase asynchronous motor, each winding of the three-phase asynchronous motor is connected between two phase lines of the single-phase step-down transformer, the three-phase asynchronous motor is provided with a mechanical switch, three-phase power (A, B and C) is respectively connected to the input end of the mechanical switch, and the output end of the mechanical switch is respectively connected to three-phase windings (U, V and W) of the three-phase asynchronous motor. The power utilization unit includes a three-phase asynchronous motor, a single-phase alternating current equipment resistor heater and a direct current equipment direct current motor, the three-phase asynchronous motor is used for simulating industrial power utilization, the single-phase alternating current equipment is used for simulating household power utilization, and the direct current equipment is used for simulating direct current power utilization, thereby forming a complete power utilization system.

[0045] Embodiment 6

[0046] The power system micro-lecture teaching device includes a first direct current power supply 1 and a second direct current power supply 9, the output end of the first direct current power supply 1 is connected with a direct current motor 2, the direct current motor 2 is connected with a direct current generator 3, the direct current generator 3 is connected in parallel with the second direct current power supply 9 and is connected with an energy storage capacitor 10; the device further includes an inverter circuit 4, the energy storage capacitor 10 is connected to the input end of the inverter circuit 4, the inverter circuit 4 is connected with a power transmission unit 5, the power transmission unit 5 is connected with a power distribution unit 7 through a power transmission network 6, and the power distribution unit 7 is connected with a power utilization unit.

[0047] A magnet is mounted on the rotor of the direct current motor 2, the direct current motor 2 is connected with the rotor of the direct current generator 3 through a belt, the direct current motor 2 is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the direct current generator 2, and the output end of the direct current generator 3 is connected with a voltage sensor.

[0048] The inverter circuit 4 is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor 10, and the LC filter circuit is connected between the inverter circuit 4 and the power transmission unit 5.

[0049] The power transmission unit comprises three single-phase step-up transformers, the three-phase output end of the inverter circuit 4 is connected with the input end of the three single-phase step-up transformers through a three-phase four-wire connection mode, and the three single-phase step-up transformers are connected through a delta connection mode.

[0050] The power distribution unit comprises three single-phase step-down transformers, and the three single-phase step-down transformers are connected with the single-phase step-up transformers through the power transmission network 6 respectively.

[0051] The power consumption unit comprises a three-phase asynchronous motor, each winding of the three-phase asynchronous motor is connected between two phase lines of the single-phase step-down transformer, the three-phase asynchronous motor is provided with a mechanical switch, three-phase power sources are connected to the input end of the mechanical switch respectively, and the output end of the mechanical switch is connected to the three-phase winding of the three-phase asynchronous motor.

[0052] The power consumption unit further comprises a resistance heater, one end of the resistance heater is connected to one phase line of any single-phase step-down transformer, and the other end of the resistance heater is connected to the neutral line in the three-phase four-wire connection mode; the resistance heater is provided with a solid-state relay, the input end of the solid-state relay is connected with the output end of the inverter circuit 4, and the output end of the solid-state relay is connected with the resistance heater; the control pin of the solid-state relay is connected with the GPIO pin of the control monitoring unit, the input end is connected with the output end of the power transformation unit, and the output end is connected with the resistance heater, so as to control the on-off of the resistance heater.

[0053] The power consumption unit further comprises a direct current motor, the direct current motor is connected with a rectification and filtering module 8, and the rectification and filtering module 8 is connected with the three-phase asynchronous motor; the direct current motor is connected to the output end of the rectification and filtering module 8, and the direct current motor is provided with a double-pole double-throw (DPDT) rotary switch; the positive and negative poles of the direct current power supply are connected to the input end of the rotary switch respectively, and the output end of the rotary switch is connected to the positive and negative poles of the direct current motor respectively; the rectification and filtering module 8 converts three-phase alternating current into direct current, the pulsating direct current after rectification is subjected to smoothing treatment through a filtering circuit, so as to reduce ripples in the current, provide more stable direct current output, and the direct current after rectification and filtering treatment can be used for direct current power consumption equipment.

[0054] The working principle of the power system micro-teaching equipment is as follows:

[0055] Turn on the first DC power supply 1, start the DC motor 2, and observe whether the output voltage of the DC generator 3 is stable through the oscilloscope; start the inverter circuit 4, and use the oscilloscope to observe the three-phase alternating voltage waveform output by the inverter circuit 4; connect the primary side of the voltage transformer to the output end of the step-up transformer, and connect the secondary side of the voltage transformer to the oscilloscope; for a three-phase asynchronous motor, use a three-phase voltmeter to measure whether the three-phase voltage (A phase, B phase, C phase) is balanced and stable, use a clamp-on ammeter to measure whether the three-phase current is balanced, and observe whether the three-phase equipment is normally started and runs smoothly without abnormal noise; for a single-phase AC equipment resistance heater, use a voltmeter to measure whether the single-phase voltage is stable, ensure that the voltage is within ±5% of the rated value, and observe whether the single-phase equipment is normally running without flickering or abnormal shutdown; for a DC motor for DC power equipment, use a DC voltmeter to measure whether the DC voltage is stable, and observe whether it is normally running without abnormal noise or shutdown; under normal operation of the system, the STM32F103 microcontroller of the inverter circuit 4 monitors the state of the energy storage capacitor in real time, and displays the voltage, current, temperature and other parameters on the OLED display screen; if the set threshold is exceeded, manually cut off the charge-discharge circuit.

[0056] The utility model power system microteaching equipment covers the core function of power system, including power generation, power transmission, power transformation, power distribution and power utilization, provides comprehensive practical content for teaching, model supports simulation of multiple power utilization scenes, helps to show power grid operation whole process visualization display and typical fault in power system operation process such as single-phase grounding fault, three-phase load imbalance, power generation power and power utilization power mismatch, improves the interactivity and practicality of teaching.

Claims

1. A power system microteaching apparatus, characterized by comprising: The application relates to a power supply system, which comprises a first direct-current power supply (1) and a second direct-current power supply (9), wherein the output end of the first direct-current power supply (1) is connected with a direct-current motor (2), the direct-current motor (2) is connected with a direct-current generator (3), and the direct-current generator (3) is connected in parallel with the second direct-current power supply (9) and has an energy storage capacitor (10); The power supply system further comprises an inverter circuit (4), the energy storage capacitor (10) is connected to the input end of the inverter circuit (4), the inverter circuit (4) is connected with a power transmission unit (5), the power transmission unit (5) is connected with a power distribution unit (7) through a power transmission network (6), and the power distribution unit (7) is connected with a power consumption unit.

2. The power system tutorial apparatus of claim 1, wherein The rotor of the direct-current motor (2) is provided with a magnet, the direct-current motor (2) is connected with the rotor of the direct-current generator (3) through a belt, the direct-current generator (3) is connected with a Hall sensor, the Hall sensor is arranged close to the rotor of the direct-current generator (3), and the output end of the direct-current generator (3) is connected with a voltage sensor.

3. The power system tutorial apparatus of claim 1, wherein The inverter circuit (4) is connected with an OLED display screen, the input end of the OLED display screen is the output end of the energy storage capacitor (10), and an LC filter circuit is connected between the inverter circuit (4) and the power transmission unit (5).

4. The power system tutorial apparatus of claim 1, wherein The power transmission unit comprises three single-phase step-up transformers, the three-phase output end of the inverter circuit (4) is connected with the input end of the three single-phase step-up transformers through a three-phase four-wire connection mode, and the three single-phase step-up transformers are connected through a delta connection mode.

5. The power system tutorial apparatus of claim 1, wherein The power distribution unit comprises three single-phase step-down transformers, and the three single-phase step-down transformers are respectively connected with the single-phase step-up transformers through the power transmission network (6).

6. The power system tutorial apparatus of claim 1, wherein The power consumption unit comprises a three-phase asynchronous motor, each winding of the three-phase asynchronous motor is connected between two phase lines of the single-phase step-down transformer, the three-phase asynchronous motor is provided with a mechanical switch, three-phase power sources are respectively connected to the input end of the mechanical switch, and the output end of the mechanical switch is respectively connected to the three-phase winding of the three-phase asynchronous motor.

7. The power system tutorial apparatus of claim 6 wherein, The power consumption unit further comprises a resistance heater, one end of the resistance heater is connected to one phase line of any single-phase step-down transformer, the other end of the resistance heater is connected to the neutral line in the three-phase four-wire, the resistance heater is provided with a solid-state relay, the input end of the solid-state relay is connected with the output end of the inverter circuit (4), and the output end of the solid-state relay is connected with the resistance heater.

8. The power system tutorial apparatus of claim 6 wherein, The power consumption unit further comprises a direct-current motor, and the direct-current motor is connected with a rectification and filtering module (8), and the rectification and filtering module (8) is connected with the three-phase asynchronous motor.

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