Power electronic twin trawling experiment platform
By designing a power electronics dual-drive experimental platform, bidirectional power conversion and controllable rectification and inversion functions were realized, solving the problems of insufficient compatibility and scalability of existing platforms, improving the practicality and safety of power electronics experiments, and meeting the needs of modern power electronics experiments.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2026-03-10
AI Technical Summary
Existing power electronics experimental platforms are inadequate in terms of compatibility, security, and scalability, failing to meet the needs of modern power electronics experiments. Furthermore, they have a single control mode and cannot perform bidirectional power conversion.
A power electronic tractor experimental platform was designed, comprising a power conversion device, a tractor motor experimental device, and an experimental control and operation device. It is connected by an SPI communication bus and a 485 communication bus to realize bidirectional power conversion, supports controllable rectification and inversion functions, and has good compatibility and security when combined with a central processing unit and a multi-layer power conversion drawer unit.
It provides an intuitive demonstration of the motor drive control principle, supports grid connection practice of new energy power generation, improves students' embedded programming skills, has good compatibility, is easy to operate, safe and reliable, has a simple structure, stable performance, and is easy to maintain.
Smart Images
Figure CN121640797A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of power electronics experimental equipment technology, and more particularly to a power electronics drag test platform. Background Technology
[0002] Power electronics technology is a discipline that uses power electronic devices to control and convert electrical energy. It is an interdisciplinary field among the three major electrical engineering technologies of power, electronics, and control. With the rapid development of research and application of power electronics technology, the training of automation students in various colleges and universities includes teaching content such as power electronics control theory. The most common and fundamental power electronics experimental control equipment or platforms generally include experiments such as semiconductor converters, AC / DC speed regulation of motors, AC frequency conversion, motor control, and control theory. These experimental control equipment or platforms generally have relatively simple control modes, mostly focusing on single-phase power conversion. A small number of experimental platforms can perform three-phase power conversion, but the experimental power is low, with an output power within 1.5KW. The control code interface is not open to external systems, making it impossible to connect to a unified platform information interaction control configuration software host computer. The human-machine interaction methods are generally rudimentary, with poor external expandability and the inability to implant new control programs. Therefore, they cannot meet the requirements of most modern power electronics experiments, resulting in significant limitations in modern power electronics technology experiments. The development of a power electronics experimental platform with good compatibility and high reliability is therefore urgently needed. Summary of the Invention
[0003] The purpose of this invention is to provide a power electronic reverse-drive experimental platform. According to this invention, a core power conversion module capable of bidirectional power conversion allows for controlled rectification on the DC side when the AC side is the input, and single-phase or three-phase inversion when the DC side is the input. It offers good compatibility and convenient experimental operation. To achieve the above objectives, this invention adopts the following technical solution:
[0004] According to one aspect of the present invention, a power electronic anti-trailer experimental platform is provided. The experimental platform includes a power conversion device, an anti-trailer motor experimental device, and an experimental control and operation device. The power conversion output terminal of the power conversion device is connected to the experimental control and operation device via an SPI communication bus. The signal terminal of the experimental control and operation device is connected to the power conversion device and the anti-trailer motor experimental device via a 485 communication bus. The power conversion device includes a power conversion cabinet, a door disposed at the opening of the power conversion cabinet, and multiple power conversion drawer units disposed from top to bottom within the power conversion cabinet. A cable interface is disposed at the lower rear side of the power conversion cabinet, which is interconnected with the rear side of each layer of power conversion drawer unit. Each layer of power conversion drawer unit is connected to the experimental control and operation device and the anti-trailer motor experimental device via a corresponding cable interface.
[0005] In a further preferred embodiment of the above scheme, the experimental control and operation device includes an experimental operating platform, a host computer, a display screen, an experimental control box, and a central processing unit (CPU) housed within the experimental control box. The host computer is located on the experimental operating platform, and the experimental control box is located on the rear side of the experimental operating platform. Operation buttons and control interfaces are respectively provided on the front and rear panels of the experimental control box. A display screen is located on the experimental control box, and the dual-drive motor experimental device is located on the rear side of the experimental operating platform. The CPU within the experimental control box is connected to the cable interfaces corresponding to each power conversion drawer unit and the dual-drive motor experimental device via the control interfaces.
[0006] In summary, because the present invention adopts the above-described technical solution, the present invention has the following technical effects:
[0007] The electronic drive experimental platform of this invention realizes the control function of the equipment, intuitively presenting the control principle of motor drive and the practice of grid connection of new energy power generation. It can truly demonstrate the application and key position of power electronics technology in real life. It can facilitate students to quickly build simulation models for verification, and can also train students' embedded programming skills. The core power conversion module can perform bidirectional power conversion. With the AC side as input, the DC side can perform controllable rectification. With the DC side as input, it can perform single-phase inversion and three-phase inversion. It has good compatibility, convenient experimental operation, safety and reliability, simple structure, stable performance, and easy maintenance. Attached Figure Description
[0008] Figure 1 This is a schematic diagram of the overall structure of a power electronics drag test platform according to the present invention;
[0009] Figure 2 This is a schematic diagram of the power conversion cabinet of the present invention;
[0010] Figure 3 This is a rear view structural diagram of the power conversion cabinet of the present invention;
[0011] Figure 4 This is a schematic diagram of the experimental principle structure of the experimental platform of the present invention;
[0012] Figure 5 This is a control principle diagram of the experimental control operation device of the present invention;
[0013] Figure 6 This is a schematic diagram of the structure of the experimental operating table of the present invention;
[0014] Figure 7 This is a schematic diagram of the structure of the experimental device for the tractor motor of the present invention;
[0015] Figure 8This is a schematic diagram of the experimental principle structure of the drag test platform of the present invention;
[0016] Figure 9 This is a control principle diagram of the first power conversion module of the present invention;
[0017] Figure 10 This is a control principle diagram of the second power conversion module of the present invention;
[0018] Figure 11 This is a schematic diagram of the structure of the first logic protection circuit of the present invention;
[0019] Figure 12 This is a schematic diagram of the circuit structure of the voltage comparator of the present invention;
[0020] Figure 13 This is a schematic diagram of the circuit structure of the first power converter and the second power converter of the present invention; in the figure, the power conversion device 1, the experimental device for the tractor motor 2, the experimental control and operation device 3, the motor set 20, the generator set 21, the torque sensor 22, the coupling 23, the power conversion cabinet 100, the power conversion drawer unit 102, the cable interface 103, the experimental operation table 301, the host computer 302, the display screen 303, the experimental control box 304, the central processing unit 305, and the drawer body 1020 of the fourth layer are all located in the experimental control box 304. Detailed Implementation
[0021] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and preferred embodiments. However, it should be noted that many details listed in the specification are merely to provide the reader with a thorough understanding of one or more aspects of the invention, and these aspects of the invention can be implemented even without these specific details.
[0022] like Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5As shown, according to the present invention, a power electronic counter-traction experimental platform includes a power conversion device 1, a counter-traction motor experimental device 2, and an experimental control and operation device 3. The power conversion output terminal of the power conversion device 1 is connected to the experimental control and operation device 3 via an SPI communication bus. The signal terminal of the experimental control and operation device 3 is connected to the power conversion device 1 and the counter-traction motor experimental device 2 via a 485 communication bus. The power conversion device 1 includes a power conversion cabinet 100, a door 101 disposed at the opening of the power conversion cabinet 100, and multiple power conversion drawer units 102 disposed from top to bottom within the power conversion cabinet 100. A cable interface 103 is disposed at the lower rear end of the power conversion cabinet 100 and interconnected with the rear side of each layer of power conversion drawer unit 102. Each layer of power conversion drawer unit 102 is connected to the experimental control and operation device 3 and the counter-traction motor experimental device 2 via a corresponding cable interface 103.
[0023] In this invention, such as Figure 1 , Figure 5 and Figure 6 As shown, the experimental control and operation device 3 includes an experimental operation table 301, a host computer 302, a display screen 303, an experimental control box 304, and a central processing unit 305 disposed in the experimental control box 304. The host computer 302 is disposed on the experimental operation table 301, and the experimental control box 304 is disposed on the rear side of the surface of the experimental operation table 301. The front panel and rear panel of the experimental control box 304 are respectively provided with operation buttons 306 and control interface 307. The display screen 303 is disposed on the experimental control box 304, and the dual-drive motor experimental device 2 is disposed on the rear side of the experimental operation table 301. The central processing unit 305 in the experimental control box 304 is connected to the cable interface 103 corresponding to each layer of power conversion drawer unit 102 and the dual-drive motor experimental device 2 through the control interface 307.
[0024] In this invention, such as Figure 1 , Figure 3As shown, the power conversion drawer unit 102 includes four drawer bodies 1020 arranged from top to bottom within the power conversion cabinet 100. The first drawer body 1020 contains multiple motor experimental control devices; the second drawer body 1020 contains multiple grid-connected experimental control devices; the third drawer body 1020 contains multiple three-phase voltage regulators; and the fourth drawer body 1020 contains multiple three-phase isolation transformers. Each three-phase isolation transformer is connected to one three-phase voltage regulator. Each motor experimental control device includes a first power conversion module and a first sampling control module. The first sampling control module is connected to the conversion input and conversion output sides of the first power conversion module, respectively. On the side, each grid-connected experimental control device includes a second power conversion module and a second sampling control module. The second sampling control module is connected to the conversion input side and conversion output side of the second power conversion module, respectively. Each three-phase isolation transformer is electrically connected to the first power conversion module and the second power conversion module through a corresponding three-phase voltage regulator. The output side of the first power conversion module is electrically connected to the input side of the tractor motor experimental device 2, and the drive output side of the tractor motor experimental device 2 is connected to the input side of the second power conversion module. The output terminals of the first sampling control module and the output terminals of the second sampling control module are connected to the central processing unit 305 through corresponding control interfaces 307, respectively. In this invention, as shown... Figure 1 , Figure 7 As shown, the experimental device 2 for the towing motor includes a motor set 20 and a generator set 21. A torque sensor 22 is installed between the transmission output end of the motor set 20 and the transmission input end of the generator set 21. The two ends of the torque sensor 22 are respectively connected to the transmission output end of the motor set 20 and the transmission input end of the generator set 21 through a coupling 23. The data output end of the torque sensor 22 is communicatively connected to the host computer 302. When the motor set 20 drives the generator set 21 to perform the towing experiment, the torque sensor 22 collects torque data and sends it to the central processing unit 305 for analysis and processing.
[0025] In this invention, Figure 4 , Figure 5 , Figure 8As shown, the first power conversion module includes a first three-phase reactor, a first three-phase contactor, a first power converter, and a second power converter; the second power conversion module includes a third power converter, a fourth power converter, a second three-phase contactor, and a second three-phase reactor; the output side of the corresponding three-phase isolation transformer is electrically connected to the first three-phase reactor, the first three-phase contactor, the first power converter, and the second power converter in sequence through corresponding three-phase voltage regulators; the output side of the second power converter is electrically connected to the power input side (three-phase input terminal) of the motor group 20; the first sampling control module is respectively connected to the first... The power converter has an input side, a second power converter has an input side and an output side; the power output side (voltage output terminal) of the generator set 21 is connected to the input side (voltage input terminal) of the third power converter, the output side of the third power converter is connected in sequence through the fourth power converter, the second three-phase contactor, and the input side of the second three-phase reactor, the output side of the second three-phase reactor is electrically connected through the corresponding three-phase voltage regulator, and the three-phase voltage regulator is connected to the corresponding three-phase isolation transformer; the second sampling control module is connected to the input side of the third power converter, the input side of the fourth power converter, and the output side of the generator set 21.
[0026] In this invention, Figure 4 , Figure 5 , Figure 9 , Figure 10 and Figure 11As shown, the first sampling control module includes a first controller, a first logic protection circuit, a first signal control circuit, a first experimental protection circuit, a first power drive circuit, and a first sampling output circuit connected to the input side of the first power converter, the input side of the second power converter, and the output side of the second power converter, respectively. The output terminal of the first sampling output circuit is connected to the acquisition input terminal of the first controller and the first input terminal of the first logic protection circuit, respectively. The control output terminal of the first controller is connected to the control terminal of the first power converter and the control terminal of the second power converter, respectively, through the first logic protection circuit and the first signal control circuit. The output terminal of the first signal control circuit is connected to the second input terminal of the first logic protection circuit. The output terminal of the first logic protection circuit is connected to the input terminal of the first experimental protection circuit and the input terminal of the first power drive circuit, respectively. The output terminal of the first power drive circuit is connected to the input control terminal of the second power converter. The circuit of the second sampling control module... The second sampling control module has the same circuit structure as the first sampling control module. It includes a second controller, a second logic protection circuit, a second signal control circuit, a second experimental protection circuit, a second power drive circuit, and a second sampling output circuit connected to the input side, input side, and output side of the third power converter, respectively. The output terminal of the second sampling output circuit is connected to the acquisition input terminal of the second controller and the first input terminal of the second logic protection circuit. The control output terminal of the second controller is connected to the control terminal of the second power converter via the second logic protection circuit and the second signal control circuit, respectively. The output terminal of the second signal control circuit is connected to the second input terminal of the second logic protection circuit. The output terminal of the second logic protection circuit is connected to the input terminal of the second experimental protection circuit and the input terminal of the second power drive circuit. The output terminal of the second power drive circuit is connected to the input control terminal of the fourth power converter. The circuit structure principle of the first logic protection circuit and the second logic protection circuit is the same, as shown below. Figure 11The first logic protection circuit includes a multi-input NAND gate, an isolation drive circuit, a signal complementary protection circuit, and a multi-channel RS flip-flop. The output terminal of the first sampling output circuit is connected to the first input terminal of each RS flip-flop. The first output terminal of each RS flip-flop is connected to the input terminal of the corresponding isolation drive circuit and the acquisition input terminal of the first controller. The power control output terminal of the first controller is connected to the control terminal of the second power converter through the signal complementary protection circuit. The second output terminal of each RS flip-flop is connected to the input terminal of the multi-input NAND gate. The output terminal of the multi-input NAND gate is connected to the input terminal of the first experimental protection circuit and the input control terminal of the first power drive circuit. The output terminal of the isolation drive circuit is connected to the input terminal of the first signal control circuit. The first and second controllers use a DSP processor or an STM32 series microcontroller. The first signal control circuit includes a transistor Q1, resistors R12, R13, and R14, a capacitor C12, a diode D11, and a diode D12. Figure 11 As shown, the base of transistor Q1 is connected to one end of resistor R13 and one end of resistor R14, respectively. The other end of resistor R14 is connected to the cathodes of diodes D11 and D12, respectively. The anode of diode D11 is connected to the output terminal of the corresponding first optocoupler isolation driver U10. The anode of diode D12 is connected to the +5V power supply through resistor R12. The +5V power supply is also connected to the second input terminal of each RS flip-flop, one end of capacitor C12, and the collector of transistor Q1 through resistor R15. The emitter of transistor Q1, the other end of resistor R13, and the other end of capacitor C12 are connected to ground. A reset switch S1 is connected to ground between the anode of diode D12 and resistor R12. Figure 11 and Figure 12 As shown, the circuit structures of the first sampling control module and the first sampling control module of the present invention are the same. Both sample the voltage or current on the bus through each voltage or current Hall sensor. The structures of the first temperature detection circuit and the second temperature detection circuit are the same, both including a temperature sensor and a voltage comparator. The temperature sensors are used to detect the heat generated by the second power converter and the fourth power converter during operation, thereby determining whether their operating temperature is too high. Figure 12As shown, the output voltage Isam / Vsam is compared with the reference voltage Vsb in a voltage comparator. The voltage comparator consists of a first comparator U12_n, a second comparator U13_n, and an auxiliary circuit connected in series. The comparison determines whether the signal at the sampling point exceeds the threshold. A large voltage signal from the power circuit of the voltage sensor (Hall sensor) is used for sampling. The voltage sensor (Hall sensor) converts the large voltage signal Vin from the power circuit into a small voltage signal Vsam. The larger Vin is, the larger Vsam is. The Vsam signal is compared with the protection threshold voltage Vsb by the voltage comparator. If Vsam is greater than Vsb, it indicates that the power circuit is overcurrent. The output signals of each voltage comparator are logically judged by an RS flip-flop, and then one signal is output through diode D10 to at most... The input terminals of the NAND gate Un are transformed by the above-mentioned three-phase voltage signal and temperature detection signal and then input to the multi-input NAND gate Un for combination judgment. The signal output by the judgment result is sent to the first experimental protection circuit. Another signal is output through resistor R10 to the first controller for logic judgment of whether it is low or high level and output to the first optocoupler isolation driver U10 for isolation drive amplification. The signal output by the first optocoupler isolation driver U10 is isolated and amplified to the anode input terminal of diode D11 of the first signal control circuit, and then fed back to the second input terminal of RS flip-flop through the discrimination circuit composed of transistor Q1. The signal output by the multi-input NAND gate Un controls the relay U11 to disconnect the AC220V equipment power supply voltage to achieve the purpose of overvoltage and overheat protection.The output of the first comparator U12_n is connected to the second comparator U13_n to modify the logic of the comparison output signal, improving the accuracy of signal judgment and preventing the generation of interference signals. Then, the two control signals H_protect and H_DSP signals output by the RS flip-flop are sent to the first optocoupler isolation driver U10 and the first controller. The first controller judges the H_DSP signal acquired from the RS flip-flop output, and the first controller outputs PWM-A and PWM-B to form a complementary protection circuit for control signals. The complementary protection circuit then controls the working state of the second power converter. The H_protect signal is sent to the first... After isolation and amplification by the optocoupler isolation driver U10, the signal is sent to the multi-input NAND gate Un for logical judgment, and then outputs a PWM_bus signal (PWM enable drive signal). Simultaneously, a protection signal output by the first controller (DSP processor or STM32 series microcontroller controller) participates in the logical operation of the multi-input NAND gate Un, changing the state of the PWM_bus output signal, thereby controlling the on / off state of the relay U11, controlling the power-on and power-off states of the equipment, and thus protecting the entire equipment operation. When the PWM_bus signal is logic "0", it indicates that a certain sampled signal has exceeded the threshold (normally logic "1"). When a specific sampling point exceeds the threshold, the RS flip-flop outputs the H_protect signal for that sampling point to the first controller for identification. The output PWM_A and PWM_B signals then cause the pulse modulation signal PWM from the complementary signal protection circuit to be cut off by relay U11 when AC 220V mains power L is connected. The voltage output from the Out pin of relay U24 is 0, thus stopping all power supply to the device. After the control logic circuit is triggered, the RS flip-flop circuit needs to be reset. The reset method is to input a logic "0" level signal to the reset pin of the RS flip-flop circuit. Under normal circumstances, the reset switch S1 of the first signal control circuit outputs a reset signal. The bit signal makes the reset pin of the RS flip-flop a logic signal "1", or the signal output by the first optocoupler isolation driver U10 is sent to the anode input of diode D11 as a reset signal, driving NPN transistor Q1 to turn on or off, pulling the voltage of the reset pin of the RS flip-flop low, thus completing the reset. Since transistor Q1 is equivalent to a switching device, the AC 220V mains line L is connected to the normally closed point of relay Un, that is, the voltage Uo output by relay Un is normally connected to L. When the PWM_bus signal is abnormally a logic "0", transistor Q1 is turned on, the output terminal Out of relay Un is connected to the floating pin NC, the equipment is powered off, and all power supply to the equipment is stopped.
[0027] In this invention, such as Figure 9 , Figure 10 , Figure 13As shown, the first power converter and the third power converter have the same structure, and the second power converter and the fourth power converter have the same structure. The first power converter includes a DC bus resistor R200, a DC bus capacitor C200, a DC voltage divider filter module, a rectifier diode D200, and an inverter voltage divider resistor R200 connected in parallel between the two poles of the bus from input to output. The second power converter includes a three-phase full-bridge inverter module connected in parallel between the two poles of the bus. The positive and negative input terminals of the three-phase full-bridge inverter module are respectively connected in parallel between the two poles of the bus on the output side of the inverter voltage divider resistor R200. The inverter input terminal of the three-phase full-bridge inverter module is connected to the first power converter. The output terminal of the power drive circuit is connected, and the inverter output terminal of the three-phase full-bridge inverter module is connected to the three-phase input terminal (power input terminal) of the motor group 20; in this invention, the DC voltage divider filter module includes a voltage divider resistor module and one or more RC filter modules connected in series. One end of the voltage divider resistor module is connected to the positive terminal of the bus, and the other end of the voltage divider resistor module is connected to the negative terminal of the bus through the RC filter module. The three-phase full-bridge inverter module includes a first switch bridge arm H1, a second switch bridge arm H2, and a third switch bridge arm H3 connected in parallel between the two poles of the bus; one end of the first switch bridge arm H1, one end of the second switch bridge arm H2, and one end of the third switch bridge arm H3 are connected in parallel between the two poles of the bus. One end of each of the three switches is connected to the positive terminal of the busbar. The other ends of the first switch arm H1, the second switch arm H2, and the third switch arm H3 are connected to the negative terminal of the busbar. The power control output of the first controller is connected to the control input of the first switch arm H1, the second switch arm H2, and the third switch arm H3 through the corresponding first power drive circuits. The inverter outputs of the first switch arm H1, the second switch arm H2, and the third switch arm H3 are connected to the three-phase input of the motor set, and the three-phase output of the motor set is connected to the three-phase input of the generator set. Terminal connection; In this invention, the first switch bridge arm H1 includes a first power transistor G1, a second power transistor G2, resistors R210 and R211, capacitors C210 and C211, diodes D210 and D211; the second switch bridge arm H2 includes a third power transistor G3, a fourth power transistor G4, resistors R212 and R213, capacitors C212 and C213, diodes D212 and D213; the third switch bridge arm H2 includes a fifth power transistor G5, a sixth power transistor G6, resistors R214 and R215, capacitors C214 and C215, diodes D214 and D215;The gates of the first power transistor G1, the second power transistor G2, the third power transistor G3, the fourth power transistor G4, the fifth power transistor G5, and the sixth power transistor G6 are respectively connected to the power control output terminal of the first controller through corresponding first power drive circuits; the drain of the first power transistor G1, one end of resistor R210, the anode of diode D210, the drain of the third power transistor G3, one end of resistor R212, the anode of diode D212, the drain of the fifth power transistor G5, and resistor R214 are also connected. One end of resistor R210 and the anode of diode D214 are connected to the positive terminal of the busbar. The other end of resistor R210 and the cathode of diode D210 are connected to one end of capacitor C210. The other end of resistor R212 and the cathode of diode D212 are connected to one end of capacitor C212. The other end of resistor R214 and the cathode of diode D214 are connected to one end of capacitor C214. The source of the first power transistor G1 is connected to the first input terminal of the three phases of the motor assembly, the drain of the second power transistor G2, the other end of capacitor C210, and the resistor... One end of resistor R211 is connected to the anode of diode D211, and the other end of resistor R211 is connected to one end of capacitor C211; the source of the second power transistor G2, the other end of capacitor C211, and the cathode of diode D211 are respectively connected to the negative terminal of the bus; the source of the third power transistor G3 is connected to the three-phase second input terminal of the motor set, the drain of the fourth power transistor G4, the other end of capacitor C212, one end of resistor R213, and the anode of diode D213, and the other end of resistor R213 is connected to one end of capacitor C213; The source of the fourth power transistor G4, the other end of capacitor C213, and the cathode of diode D213 are respectively connected to the negative terminal of the bus. The source of the fifth power transistor G5 is connected to the third input terminal of the three-phase motor, the drain of the sixth power transistor G6, the other end of capacitor C214, one end of resistor R215, and the anode of diode D215. The other end of resistor R215 is connected to one end of capacitor C215. The source of the sixth power transistor G6, the other end of capacitor C215, and the cathode of diode D215 are respectively connected to the negative terminal of the bus. In this invention, resistor R210 and capacitor C210 can divide the voltage across the first power transistor G1, removing coupling noise and preventing excessively rapid changes in voltage or current. Diode D210 clamps excessively high voltages, thus protecting the power transistors.The signal complementary protection circuit includes a first two-input NAND gate U31, a second two-input NAND gate U32, a third two-input NAND gate U33, resistors R30, R31, R32, R33, and R3, a diode D31, a first boost isolation module U34, and a second boost isolation module U35. The first signal output terminal PWM_A of the second controller is connected to the first input terminal of the first two-input NAND gate U31, one end of resistor R30, and the first input terminal of the second two-input NAND gate U32. The second signal output terminal PWM_B of the second controller is connected to one end of resistor R31, the second input terminal of the first two-input NAND gate U31, and the second input terminal of the third two-input NAND gate U33. The output terminal of the first two-input NAND gate is connected to resistor R32. One end of the resistor R32 is connected to the diode D31, the second input of the second two-input NAND gate U32, and the first input of the third two-input NAND gate U33. The cathode of the diode D31 is connected to the output of the multi-input NAND gate Un. The first boost isolation module U34 and the second boost isolation module U35 are sampling optocoupler isolation drivers. The output of the second two-input NAND gate U32 is connected to the first input control terminal of the first boost isolation module U34 through the resistor R33. The output of the third two-input NAND gate U33 is connected to the second input control terminal of the second boost isolation module U35 through the resistor R34. The outputs of the first boost isolation module U34 and the second boost isolation module U35 are respectively connected to the gates of the corresponding power transistors.
[0028] In this invention, such as Figure 13As shown, the three-phase full-bridge inverter module consists of three bridge arms (power switches G1 to G6) composed of six enhancement-mode MOSFET power switches. The voltage, current, or temperature signals sampled by the sampling output circuit are sent to the controller for AD conversion. The converted signals are then analyzed to determine if there are overcurrent, overvoltage, or overheating phenomena. Consequently, the bridge arms composed of the six power switches G1 to G6 are controlled by two pulse control signals, PWM-A and PWM-B, output by the controller. The PWM-A signal passes through the first input terminal of the first input NAND gate U31, the first input terminal of the second input NAND gate U32, and the PW... The M-B signal is logically judged through the second input terminal of the first input NAND gate U31 and the first input terminal of the third two-input NAND gate U33. The output signal after each judgment is sent to the corresponding first boost isolation module U34 or / and second boost isolation module U35 through resistor R33 and / or resistor R34. For this purpose, the first controller uses the output pulse modulation wave to control the bridge arm composed of six power switches G1 to G6. As can be seen from the bridge arm composed of six power switches, the upper and lower switches in the same bridge arm cannot be turned on simultaneously. For example, G1 and G2 cannot be turned on simultaneously, otherwise a voltage drop on the DC side will cause a short circuit. Therefore, the first controller uses the output modulation wave PWM phase control to protect the first power converter. Figure 5 As shown, when PWM-A and PWM-B are both logic signals "1", PWM-A and PWM-B are also logic signals "1". The first two-input NAND gate U31 outputs a low level "0", and the second two-input NAND gate U32 and the third two-input NAND gate U33 output a high level "1". Therefore, there is no signal on the G1 and G3 sides. Only when one of PWM1 and PWM2 is "1" and the other is "0" will one of G1 and G2 have a signal, and both G1 and G3 sides will have signal output. When the PWM_bus signal is logic signal "0", the PWM-A and PWM-B signals are invalidated. The first boost isolation module U34 and the second boost isolation module U35 use optocouplers to amplify the PWM signal (the control voltage of the G1-G6 switching transistors is 15V) and isolate the high-voltage signal from the low-voltage control signal. They sequentially control the conduction or cutoff sequence of the six power transistors, thereby converting DC power into three-phase AC power.
[0029] In this invention, such as Figure 13A short-circuit control switch J0 is connected in parallel across the two ends of the voltage divider resistor module. The control terminal of the short-circuit control switch J0 is connected to the control output terminal of the first controller. The voltage divider resistor module consists of multiple parallel voltage divider resistors R0. The short-circuit control switch J0 is a relay switch. By controlling the short-circuit control switch J0 to short-circuit the multiple parallel voltage divider resistors R0, the resistance of the first power converter is adjusted, thereby achieving the purpose of adjusting the output voltage. Each RC filter module consists of a first filter module composed of a filter capacitor C0 connected in parallel and an energy storage voltage divider resistor R1, and a second filter module composed of a capacitor C1 connected in parallel and an energy storage voltage divider resistor R2. The first filter module and the second filter module are connected in series at one end to one end of the voltage divider resistor module, and the other end of the first filter module and the second filter module are connected in series to the negative terminal of the bus. The number of filter capacitors C0 and C1 is one or more, and the number of energy storage voltage divider resistors R1 and R1 is one or more. In this invention, multiple filter capacitors C0 and multiple energy storage voltage divider resistors R1 are connected in parallel to form a group of RC filter modules. Multiple parallel RC filter modules are connected in series in sequence to form multiple groups of interconnected RC filter modules, thereby improving the rectification and conversion electrical performance of the entire first power converter.
[0030] In the motor experiment control device, 380V three-phase power is obtained from the mains power grid. After coupling and conversion by a three-phase isolation transformer and a three-phase voltage regulator, 500V DC power is output. Then, after rectification by the first three-phase reactor, the first three-phase contactor, and the first power converter, the second power converter performs inversion output, realizing three-phase input to the second power converter (bidirectional power conversion and rectification), and inverted output three-phase power with the same amplitude, frequency, and phase as the power grid. The three-phase electric motor set 20 works with (the driven motor can be replaced by generator set 21) generator set 21 to conduct a drag test. During the drag test, the bus between the three-phase output side of the motor 20 and the third power converter can be disconnected. The generator set 21 and the motor 20 are connected using a coaxial torque sensor, and the drag test data is obtained through the torque sensor. After rectification and inversion by the first and second power converters, three-phase electricity with the same amplitude, frequency, and phase as the power grid is generated and connected to the grid. The equipment draws power from the three-phase power grid and drives the motor unit 20 through AC-DC-AC power conversion for motor control. At this time, the motor unit 20 drives the generator unit 21 to generate electricity. The generated AC power can be fed back to the grid after AC-DC-AC power conversion. The former can simulate the motor drive process of new energy vehicles, and the latter can simulate the energy conversion process of new energy power generation and grid connection.
[0031] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A power electronic contra-rotating experiment platform, the experiment platform comprising a power conversion device, a contra-rotating motor experiment device and an experiment control operation device, characterized in that: The power conversion output end of the power conversion device is connected with the experimental control operation device through an SPI communication bus, and the signal end of the experimental control operation device is respectively connected with the power conversion device and the motor experiment device through a 485 communication bus, the power conversion device comprises a power conversion cabinet body, a door body arranged at the opening of the power conversion cabinet body, and a plurality of layers of power conversion drawer units arranged from top to bottom in the power conversion cabinet body, a cable line interface connected with the rear side of each layer of power conversion drawer unit is arranged at the lower end of the rear side of the power conversion cabinet body, and each layer of power conversion drawer unit is connected with the experimental control operation device and the motor experiment device through the corresponding cable line interface.
2. The power electronic counterpart experiment platform according to claim 1, characterized in that: The experimental control operation device comprises an experimental operation table, a host computer, a display screen, an experimental control box 304 and a central processing unit arranged in the experimental control box, the host computer is arranged on the experimental operation table, the experimental control box is arranged on the rear side of the surface of the experimental operation table, operation buttons and control interfaces are respectively arranged on the front panel and the rear panel of the experimental control box, the display screen is arranged on the experimental control box, and the central processing unit in the experimental control box is connected with the corresponding cable line interface of each layer of power conversion drawer unit and the motor experiment device through the control interface.
3. The power electronic counterpart experiment platform according to claim 2, characterized in that: The power conversion drawer unit comprises four layers of drawer bodies arranged from top to bottom in the power conversion cabinet body, wherein the first layer of drawer body is provided with a plurality of motor experiment control devices, the second layer of drawer body is provided with a plurality of grid-connected experiment control devices, the third layer of drawer body is provided with a plurality of three-phase voltage regulators, and the fourth layer of drawer body is provided with a plurality of three-phase isolation transformers, each three-phase isolation transformer is connected with one three-phase voltage regulator, each motor experiment control device comprises a first power conversion module and a first sampling control module, the first sampling control module is respectively connected on the conversion input side and the conversion output side of the first power conversion module, each grid-connected experiment control device comprises a second power conversion module and a second sampling control module, the second sampling control module is respectively connected on the conversion input side and the conversion output side of the second power conversion module, each three-phase isolation transformer is electrically connected with the first power conversion module and the second power conversion module through the corresponding three-phase voltage regulator in sequence, the output side of the first power conversion module is electrically connected with the input side of the motor experiment device, the driving output side of the motor experiment device is connected with the input side of the second power conversion module, and the input end of the first sampling control module and the output end of the second sampling control module are respectively connected with the central processing unit through the corresponding control interface; the motor experiment device comprises a motor set and a generator set, a torque sensor is arranged between the transmission output end of the motor set and the transmission input end of the generator set, the two ends of the torque sensor are respectively drivingly connected with the transmission output end of the motor set and the transmission input end of the generator set through couplings, and the data output end of the torque sensor is in communication connection with the host computer.
4. The power electronic counterpart test platform of claim 3, wherein: The first power conversion module comprises a first three-phase reactor, a first three-phase contactor, a first power converter and a second power converter; the second power conversion module comprises a third power converter, a fourth power converter, a second three-phase contactor and a second three-phase reactor; The output side of the corresponding three-phase isolation transformer is electrically connected with the first three-phase reactor, the first three-phase contactor, the first power converter and the second power converter through the corresponding three-phase voltage regulator in sequence, and the output side of the second power converter is electrically connected with the power input side of the motor set; the first sampling control module is connected with the input side of the first power converter, the input side and the output side of the second power converter respectively; The power output side of the generator set is connected with the input side of the third power converter, the output side of the third power converter is connected with the input side of the fourth power converter, the second three-phase contactor and the second three-phase reactor in sequence, and the output side of the second three-phase reactor is electrically connected with the corresponding three-phase voltage regulator which is connected with the corresponding three-phase isolation transformer; the second sampling control module is connected with the input side of the third power converter, the input side and the output side of the fourth power converter respectively.
5. The power electronic ship-to-ship trial platform according to claim 3 or 4, characterized in that: The first sampling control module comprises a first controller, a first logic protection circuit, a first signal control circuit, a first experiment protection circuit, a first power driving circuit and a first sampling output circuit connected with the input side of the first power converter, the input side and the output side of the second power converter respectively, the output end of the first sampling output circuit is connected with the acquisition input end of the first controller and the first input end of the first logic protection circuit respectively, the control output end of the first controller is connected with the control end of the first power converter and the control end of the second power converter through the first logic protection circuit and the first signal control circuit in sequence, the output end of the first signal control circuit is connected with the second input end of the first logic protection circuit, the output end of the first logic protection circuit is connected with the input end of the first experiment protection circuit and the input end of the first power driving circuit respectively, and the output end of the first power driving circuit is connected with the input control end of the second power converter. The second sampling control module comprises a second controller, a second logic protection circuit, a second signal control circuit, a second experiment protection circuit, a second power drive circuit and a second sampling output circuit connected at the input side of the third power converter, the input side and the output side of the third power converter respectively, the output end of the second sampling output circuit is connected with the collection input end of the second controller and the first input end of the second logic protection circuit respectively, the control output end of the second controller is connected with the control end of the second power converter and the control end of the second power converter through the second logic protection circuit and the second signal control circuit respectively in turn, the output end of the second signal control circuit is connected with the second input end of the second logic protection circuit, the output end of the second logic protection circuit is connected with the input end of the second experiment protection circuit and the input end of the second power drive circuit, and the output end of the second power drive circuit is connected with the input control end of the fourth power converter.
6. The power electronic counterpart test platform of claim 5, wherein: The first logic protection circuit comprises a plurality of input NAND gates, an isolation drive circuit, a signal complementary protection circuit and a plurality of RS flip-flops, the output end of the first sampling output circuit is connected with the first input end of each RS flip-flop, the first output end of each RS flip-flop is connected with the input end of the corresponding isolation drive circuit and the collection input end of the first controller respectively, the power control output end of the first controller is connected with the control end of the second power converter through the signal complementary protection circuit, the second output end of each RS flip-flop is connected with the input end of the plurality of input NAND gates respectively, the output end of the plurality of input NAND gates is connected with the input end of the first experiment protection circuit and the input control end of the first power drive circuit respectively, and the output end of the isolation drive circuit is connected with the input end of the first signal control circuit.
7. The power electronic counterpart test platform of claim 5, wherein: The first power converter comprises a DC bus resistance R200, a DC bus capacitance C200, a DC voltage division filter module, a rectifier diode D200 and an inverter voltage division resistance R200 connected in parallel between the two poles of the bus from the input side to the output side in turn, the second power converter comprises a three-phase full-bridge inverter module connected in parallel between the two poles of the bus, the positive and negative input ends of the three-phase full-bridge inverter module are connected in parallel between the two poles of the bus at the output side of the two ends of the inverter voltage division resistance R200 respectively, the inverter input end of the three-phase full-bridge inverter module is connected with the output end of the first power drive circuit, and the inverter output end of the three-phase full-bridge inverter module is connected with the three-phase input end of the motor set.
8. The power electronic counterpart test platform of claim 7, wherein: The direct current voltage division filter module comprises a voltage division resistor module and one or more RC filter modules connected in series with each other, one end of the voltage division resistor module is connected to the positive pole of the bus, the other end of the voltage division resistor module is connected to the negative pole of the bus through the RC filter module, the three-phase full-bridge inverter module comprises a first switching bridge arm H1, a second switching bridge arm H2 and a third switching bridge arm H3 connected in parallel between the two poles of the bus, one end of the first switching bridge arm H1, one end of the second switching bridge arm H2 and one end of the third switching bridge arm H3 are connected to the positive pole of the bus, the other end of the first switching bridge arm H1, the other end of the second switching bridge arm H2 and the other end of the third switching bridge arm H3 are connected to the negative pole of the bus, the power control output end of the first controller is connected to the control input end of the first switching bridge arm H1, the control input end of the second switching bridge arm H2 and the control input end of the third switching bridge arm H3 through the corresponding first power drive circuit, the inverter output end of the first switching bridge arm H1, the inverter output end of the second switching bridge arm H2 and the inverter output end of the third switching bridge arm H3 are connected to the three-phase input end of the motor set, and the power output side of the generator set is connected to the input side of the third power converter.
9. The power electronic counterpart test platform of claim 8, wherein: A short circuit control switch J0 is further connected in parallel at the two ends of the voltage division resistor module, the control end of the short circuit control switch J0 is connected to the control output end of the first controller, the voltage division resistor module is composed of a plurality of parallel voltage division resistors R0, each RC filter module is composed of a filter capacitor and an energy storage voltage division resistor R1 connected in parallel, the number of filter capacitors is one or more, and the number of energy storage voltage division resistors R1 is one or more.
10. The power electronic counterpart experiment platform according to claim 8, characterized in that: The first switching bridge arm H1 comprises a first power tube G1, a second power tube G2, a resistor R210, a resistor R211, a capacitor C210, a capacitor C211, a diode D210 and a diode D211, the second switching bridge arm H2 comprises a third power tube G3, a fourth power tube G4, a resistor R212, a resistor R213, a capacitor C212, a capacitor C213, a diode D212 and a diode D213, and the third switching bridge arm H2 comprises a fifth power tube G5, a sixth power tube G6, a resistor R214, a resistor R215, a capacitor C214, a capacitor C215, a diode D214 and a diode D215, the gate of the first power tube G1, the gate of the second power tube G2, the gate of the third power tube G3, the gate of the fourth power tube G4, the gate of the fifth power tube G5 and the gate of the sixth power tube G6 are connected to the power control output end of the first controller through the corresponding first power drive circuit, The drain of the first power tube G1, one end of the resistor R210, the anode of the diode D210, the drain of the third power tube G3, one end of the resistor R212, the anode of the diode D212, the drain of the fifth power tube G5, one end of the resistor R214, the anode of the diode D214 are connected to the positive pole of the bus respectively, the other end of the resistor R210 and the cathode of the diode D210 are connected to one end of the capacitor C210 respectively, the other end of the resistor R212 and the cathode of the diode D212 are connected to one end of the capacitor C212 respectively, the other end of the resistor R214 and the cathode of the diode D214 are connected to one end of the capacitor C214 respectively; The source of the first power tube G1 is connected to the three-phase first input end of the motor group, the drain of the second power tube G2, the other end of the capacitor C210 and one end of the resistor R211, the anode of the diode D211 respectively, the other end of the resistor R211 is connected to one end of the capacitor C211; the source of the second power tube G2, the other end of the capacitor C211 and the cathode of the diode D211 are connected to the negative pole of the bus respectively; The source of the third power tube G3 is connected to the three-phase second input end of the motor group, the drain of the fourth power tube G4, the other end of the capacitor C212 and one end of the resistor R213, the anode of the diode D213 respectively, the other end of the resistor R213 is connected to one end of the capacitor C213; the source of the fourth power tube G4, the other end of the capacitor C213 and the cathode of the diode D213 are connected to the negative pole of the bus respectively; The source of the fifth power tube G5 is connected to the three-phase third input end of the motor group, the drain of the sixth power tube G6, the other end of the capacitor C214 and one end of the resistor R215, the anode of the diode D215 respectively, the other end of the resistor R215 is connected to one end of the capacitor C215; the source of the sixth power tube G6, the other end of the capacitor C215 and the cathode of the diode D215 are connected to the negative pole of the bus respectively.