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Volume 47,Issue 12,2020 Table of Contents
2020, 47(12):1-9.
DOI: 10.12177/emca.2020.166
Abstract:
The dynamometer system for the measurement of power and torque of power machinery equipment is mainly composed of dynamometer motor, dynamometer mechanism and control system. Such systems are widely used in performance testing of mechanical transmission components. The importance of the dynamometer system in the industrial field is briefly described. The classification of dynamometer systems is summarized, and the advantages and disadvantages of all kinds of dynamometers are analyzed. The structure, principle and application scenarios of the current dynamometer systems are introduced. Several classic control strategies of dynamometer systems are summarized. Finally, the application of dynamometer in the performance test of transmission, gearbox, engine and automobile chassis is introduced.
The dynamometer system for the measurement of power and torque of power machinery equipment is mainly composed of dynamometer motor, dynamometer mechanism and control system. Such systems are widely used in performance testing of mechanical transmission components. The importance of the dynamometer system in the industrial field is briefly described. The classification of dynamometer systems is summarized, and the advantages and disadvantages of all kinds of dynamometers are analyzed. The structure, principle and application scenarios of the current dynamometer systems are introduced. Several classic control strategies of dynamometer systems are summarized. Finally, the application of dynamometer in the performance test of transmission, gearbox, engine and automobile chassis is introduced.
2020, 47(12):10-16.
DOI: 10.12177/emca.2020.157
Abstract:
During the starting process of aero-engine starter motor, the load characteristics change with the speed. At the same time, the difference of starting environment and the change of motor parameters bring difficulties to the start-up control. In order to overcome the shortcomings of traditional control strategies in dealing with these uncertainties, a fractional order active disturbance rejection controller based on random evolution grey wolf optimization (REGWO-FO-ADRC) is proposed. Through the active disturbance rejection control (ADRC), anti-disturbance capability of the system in the starting process is enhanced. The fractional order (FO) control is adopted to suppress the observer estimation error caused by the upper limit of bandwidth and ensure the control quality. The random evolution grey wolf optimization (REGWO) algorithm is designed to realize online self-adaption of the control parameters of the FO controller. The variable evolutionary rate is used to describe the update process of population, which enriches the randomness and improves the global search ability and convergence speed. Simulation results show that the designed controller can effectively suppress the influence of many uncertainties on the system and improve the starting performance of aero-engine.
During the starting process of aero-engine starter motor, the load characteristics change with the speed. At the same time, the difference of starting environment and the change of motor parameters bring difficulties to the start-up control. In order to overcome the shortcomings of traditional control strategies in dealing with these uncertainties, a fractional order active disturbance rejection controller based on random evolution grey wolf optimization (REGWO-FO-ADRC) is proposed. Through the active disturbance rejection control (ADRC), anti-disturbance capability of the system in the starting process is enhanced. The fractional order (FO) control is adopted to suppress the observer estimation error caused by the upper limit of bandwidth and ensure the control quality. The random evolution grey wolf optimization (REGWO) algorithm is designed to realize online self-adaption of the control parameters of the FO controller. The variable evolutionary rate is used to describe the update process of population, which enriches the randomness and improves the global search ability and convergence speed. Simulation results show that the designed controller can effectively suppress the influence of many uncertainties on the system and improve the starting performance of aero-engine.
2020, 47(12):17-24.
DOI: 10.12177/emca.2020.148
Abstract:
Due to the time-varying nonlinear characteristic of switched reluctance motor (SRM), it is difficult to establish an accurate mathematical model. When the internal and external disturbances are large, the traditional PID controller cannot meet the requirement of high control performance. To solve these problems, a linear active disturbance rejection control (LADRC) method is used to design the speed controller of SRM. The uncertainty of the nonlinear model and the sudden change of load are synthesized as a total disturbance, and a linear extended state observer is designed to estimate and compensate the disturbance. A second-order Lagrange polynomial interpolation is used to approximate the position trajectory of SRM, thus the instantaneous speed can be calculated. The rotor position is estimated according to the instantaneous speed while SRM is operated under the conduction angular control mode. The simulation result shows that the LADRC controller is superior to the traditional PID controller. Finally, real-time control experiment of a 6/4 SRM is carried out using a DSP28335 board. The results show that the LADRC combined with the second-order Lagrange interpolation speedometer can realize the conduction angular control of SRM with early on/off operation.
Due to the time-varying nonlinear characteristic of switched reluctance motor (SRM), it is difficult to establish an accurate mathematical model. When the internal and external disturbances are large, the traditional PID controller cannot meet the requirement of high control performance. To solve these problems, a linear active disturbance rejection control (LADRC) method is used to design the speed controller of SRM. The uncertainty of the nonlinear model and the sudden change of load are synthesized as a total disturbance, and a linear extended state observer is designed to estimate and compensate the disturbance. A second-order Lagrange polynomial interpolation is used to approximate the position trajectory of SRM, thus the instantaneous speed can be calculated. The rotor position is estimated according to the instantaneous speed while SRM is operated under the conduction angular control mode. The simulation result shows that the LADRC controller is superior to the traditional PID controller. Finally, real-time control experiment of a 6/4 SRM is carried out using a DSP28335 board. The results show that the LADRC combined with the second-order Lagrange interpolation speedometer can realize the conduction angular control of SRM with early on/off operation.
2020, 47(12):25-31.
DOI: 10.12177/emca.2020.160
Abstract:
The conventional surface permanent magnet synchronous motor (SPMSM) model predictive torque control (MPTC) system uses all 7 voltage vectors generated by voltage source inverter (VSI), which causes large calculation burden. As zero voltage vector changes stator flux and torque very slowly, it is often used to maintain stator flux and torque when the torque error is small. The utilization rates of zero voltage vector in SPMSM MPTC system at different bands of torque error are analyzed. A simplified control strategy for SPMSM MPTC system based on band of torque error is proposed. When the torque error is within the band, the system outputs zero voltage vector directly without the MPTC calculation, otherwise 6 non-zero voltage vectors are used as candidate voltage vectors for MPTC. Simulation results show that the proposed SPMSM MDTC system works properly. Compared with the conventional MPTC, the control performance of the proposed system is almost the same, but the average switching frequency and the average MPTC calculation time decrease to 20% and 12.43% of those of the conventional one, respectively. Therefore, the simplified control strategy reduces the calculation burden dramatically.
The conventional surface permanent magnet synchronous motor (SPMSM) model predictive torque control (MPTC) system uses all 7 voltage vectors generated by voltage source inverter (VSI), which causes large calculation burden. As zero voltage vector changes stator flux and torque very slowly, it is often used to maintain stator flux and torque when the torque error is small. The utilization rates of zero voltage vector in SPMSM MPTC system at different bands of torque error are analyzed. A simplified control strategy for SPMSM MPTC system based on band of torque error is proposed. When the torque error is within the band, the system outputs zero voltage vector directly without the MPTC calculation, otherwise 6 non-zero voltage vectors are used as candidate voltage vectors for MPTC. Simulation results show that the proposed SPMSM MDTC system works properly. Compared with the conventional MPTC, the control performance of the proposed system is almost the same, but the average switching frequency and the average MPTC calculation time decrease to 20% and 12.43% of those of the conventional one, respectively. Therefore, the simplified control strategy reduces the calculation burden dramatically.
2020, 47(12):32-37.
DOI: 10.12177/emca.2020.153
Abstract:
Aiming at the thermal comfort of human body and considering the complexity of air conditioner control system, the control strategy of double-evaporator air conditioning system of SUV6 is optimized. On the basis of joint simulation, the closed-loop control system of automobile air conditioner based on fuzzy-PID control is established. Particle swarm optimization (PSO) is introduced to optimize the parameters of PID controller and regulate the fan speed and compressor opening ratio. Compared with the PID control and the fuzzy-PID control, it is found that the fuzzy-PID control based on PSO can overcome the defect of overshoot, make the temperature in the passenger compartment approach to the target faster and more stably, reduce the temperature control error, effectively reduce the energy consumption of the car, and meet the requirements of energy saving and consumption reduction.
Aiming at the thermal comfort of human body and considering the complexity of air conditioner control system, the control strategy of double-evaporator air conditioning system of SUV6 is optimized. On the basis of joint simulation, the closed-loop control system of automobile air conditioner based on fuzzy-PID control is established. Particle swarm optimization (PSO) is introduced to optimize the parameters of PID controller and regulate the fan speed and compressor opening ratio. Compared with the PID control and the fuzzy-PID control, it is found that the fuzzy-PID control based on PSO can overcome the defect of overshoot, make the temperature in the passenger compartment approach to the target faster and more stably, reduce the temperature control error, effectively reduce the energy consumption of the car, and meet the requirements of energy saving and consumption reduction.
2020, 47(12):38-42.
DOI: 10.12177/emca.2020.151
Abstract:
In order to overcome the problem of speed overshoot and improve the anti-disturbance ability of PI control in the permanent magnet synchronous motor (PMSM) speed control system, a novel exponential reaching law with strong adaptive ability is proposed. This novel reaching law, based on the traditional exponential reaching law, improves the isokinetic term coefficient to a time-varying term, which can make the system converge to a given value faster, and the problem of the slow convergence speed of the traditional exponential reaching law is solved. In addition, the saturation function of the variable boundary layer is used to replace the traditional switching function to weaken the sliding mode chattering phenomenon. Lyapunov stability theory is used to analyze the stability of the novel exponential reaching law, and the speed loop sliding mode controller is designed based on the novel law. The designed controller is compared with PI control by MATLAB modeling and simulation. The simulation results show that the speed loop sliding mode controller based on the novel law can effectively improve the robustness of the PMSM speed control system.
In order to overcome the problem of speed overshoot and improve the anti-disturbance ability of PI control in the permanent magnet synchronous motor (PMSM) speed control system, a novel exponential reaching law with strong adaptive ability is proposed. This novel reaching law, based on the traditional exponential reaching law, improves the isokinetic term coefficient to a time-varying term, which can make the system converge to a given value faster, and the problem of the slow convergence speed of the traditional exponential reaching law is solved. In addition, the saturation function of the variable boundary layer is used to replace the traditional switching function to weaken the sliding mode chattering phenomenon. Lyapunov stability theory is used to analyze the stability of the novel exponential reaching law, and the speed loop sliding mode controller is designed based on the novel law. The designed controller is compared with PI control by MATLAB modeling and simulation. The simulation results show that the speed loop sliding mode controller based on the novel law can effectively improve the robustness of the PMSM speed control system.
2020, 47(12):43-48.
DOI: 10.12177/emca.2020.147
Abstract:
Open winding linear vernier permanent magnet (LVPM) motor has the advantages of high DC voltage utilization, high thrust density and low cost of construction and maintenance. It is very suitable for the construction of urban rail transit. However, when the traditional direct thrust control is adopted, the thrust and flux ripples of the motor are large, and the switching frequency of the power unit is unstable. Aiming at the above problems, the mathematical model of LVPM motor is analyzed, the direct thrust control strategy based on space vector pulse width modulation (SVPWM) is studied, and a target vector decoupling control strategy is proposed. The simulation results verify the correctness of the proposed method.
Open winding linear vernier permanent magnet (LVPM) motor has the advantages of high DC voltage utilization, high thrust density and low cost of construction and maintenance. It is very suitable for the construction of urban rail transit. However, when the traditional direct thrust control is adopted, the thrust and flux ripples of the motor are large, and the switching frequency of the power unit is unstable. Aiming at the above problems, the mathematical model of LVPM motor is analyzed, the direct thrust control strategy based on space vector pulse width modulation (SVPWM) is studied, and a target vector decoupling control strategy is proposed. The simulation results verify the correctness of the proposed method.
2020, 47(12):49-53.
DOI: 10.12177/emca.2020.131
Abstract:
Based on the sensorless control technology of permanent magnet synchronous motor (PMSM), a constant power control algorithm for the PMSM of household electrical appliances is put forward. In the proposed method, the calculated motor power is adjusted with Kalman filtering to achieve high precision, and a power control loop with power tracking functionality is designed, so as to adaptively realize the maximum power control of the PMSM. The design of controller and motor drive is implemented. Test results show that, with the proposed method, the washing machine motor can keep working at the maximum power status.
Based on the sensorless control technology of permanent magnet synchronous motor (PMSM), a constant power control algorithm for the PMSM of household electrical appliances is put forward. In the proposed method, the calculated motor power is adjusted with Kalman filtering to achieve high precision, and a power control loop with power tracking functionality is designed, so as to adaptively realize the maximum power control of the PMSM. The design of controller and motor drive is implemented. Test results show that, with the proposed method, the washing machine motor can keep working at the maximum power status.
2020, 47(12):54-59.
DOI: 10.12177/emca.2020.156
Abstract:
Aiming at the special structure of the controllable excitation magnetic levitation linear synchronous motor used to drive the CNC machine tool, the magnetic-thermal coupling mechanism is studied. The influence of the magnetic field on the temperature rise of the motor at different armature currents is analyzed. The differential equation of heat conduction in the two-dimensional temperature field of the motor, the Newtonian cooling formula of heat convection and the boundary conditions of the temperature field are established. The thermal conductivity and convective heat transfer coefficient of different materials of the motor are determined, and the analytical expression of the convective heat transfer coefficient is given. Using ANSYS finite element simulation method in the magnetic-thermal coupling analysis, the main heat sources of the motor are analyzed. The ANSYS Maxwell software is used to calculate the motor stator and rotor losses, which are used as the motor heat source and imported into the Workbench software for thermal analysis to obtain the temperature distribution cloud diagram of the motor when different armature currents are applied. The simulation results show that the heat in the controllable excitation magnetic levitation linear synchronous motor is mainly concentrated in the windings，and the temperature increases with the increase of the armature current. The calculated data of temperature field can provide the basis for motor design.
Aiming at the special structure of the controllable excitation magnetic levitation linear synchronous motor used to drive the CNC machine tool, the magnetic-thermal coupling mechanism is studied. The influence of the magnetic field on the temperature rise of the motor at different armature currents is analyzed. The differential equation of heat conduction in the two-dimensional temperature field of the motor, the Newtonian cooling formula of heat convection and the boundary conditions of the temperature field are established. The thermal conductivity and convective heat transfer coefficient of different materials of the motor are determined, and the analytical expression of the convective heat transfer coefficient is given. Using ANSYS finite element simulation method in the magnetic-thermal coupling analysis, the main heat sources of the motor are analyzed. The ANSYS Maxwell software is used to calculate the motor stator and rotor losses, which are used as the motor heat source and imported into the Workbench software for thermal analysis to obtain the temperature distribution cloud diagram of the motor when different armature currents are applied. The simulation results show that the heat in the controllable excitation magnetic levitation linear synchronous motor is mainly concentrated in the windings，and the temperature increases with the increase of the armature current. The calculated data of temperature field can provide the basis for motor design.
10 Influence of No-Load Back EMF of Permanent Magnet Synchronous Motor on Driving System Performance
2020, 47(12):60-64.
DOI: 10.12177/emca.2020.150
Abstract:
The influence of no-load back electromotive force (EMF) of permanent magnet synchronous motor (PMSM) on power factor is analyzed. The mathematical models of the influence of the PMSM no-load back EMF on single-drive and multi-drive converters are established. The calculation results show that the converter with multi-drive structure can tolerate higher no-load back EMF of PMSM, and significantly improve the efficiency of the driving system.
The influence of no-load back electromotive force (EMF) of permanent magnet synchronous motor (PMSM) on power factor is analyzed. The mathematical models of the influence of the PMSM no-load back EMF on single-drive and multi-drive converters are established. The calculation results show that the converter with multi-drive structure can tolerate higher no-load back EMF of PMSM, and significantly improve the efficiency of the driving system.
2020, 47(12):65-69.
DOI: 10.12177/emca.2020.173
Abstract:
Robot joint motors have higher requirements for the motor′s overload capacity, motor weight and response speed. However, the traditional torque motor has larger rotor outer diameter, rotor mass and moment of inertia, and thus slower response. Based on the Halbach array, a joint motor for robots is designed. The magnetic shielding effect of the Halbach array is utilized, and non-magnetic aluminum alloy is used as the material of the rotor yoke, so as to reduce the mass and moment of inertia of the rotor and improve the response speed of the motor. The advantages of Halbach array are analyzed. Several common Halbach array structures are listed. The size parameters of the motor are determined. The influence of the size of the magnetic steel based on the Halbach array on the performance of the motor is analyzed by the electromagnetic field finite element simulation. Finally, the effectiveness of the technology is verified by experiments.
Robot joint motors have higher requirements for the motor′s overload capacity, motor weight and response speed. However, the traditional torque motor has larger rotor outer diameter, rotor mass and moment of inertia, and thus slower response. Based on the Halbach array, a joint motor for robots is designed. The magnetic shielding effect of the Halbach array is utilized, and non-magnetic aluminum alloy is used as the material of the rotor yoke, so as to reduce the mass and moment of inertia of the rotor and improve the response speed of the motor. The advantages of Halbach array are analyzed. Several common Halbach array structures are listed. The size parameters of the motor are determined. The influence of the size of the magnetic steel based on the Halbach array on the performance of the motor is analyzed by the electromagnetic field finite element simulation. Finally, the effectiveness of the technology is verified by experiments.
2020, 47(12):70-75.
DOI: 10.12177/emca.2020.164
Abstract:
The aim of the research is to design a permanent magnet generator with rated power of 300 kW and rated speed of 2 700 r/min. For this generator, the center height should be no more than 225 mm, and the power density is about 6 times that of ordinary generator. Therefore, the temperature rise control of the generator has become an urgent issue. In order to reduce the temperature rise of the generator, the water cooling frame is designed. Through the finite element simulation calculation, it is found that the temperature rise at the end of the generator winding is still high. In order to further reduce the winding end temperature rise, four axial ventilation channels are added on the basis of the raw water cooler base, and the heat exchange between the cooling water and the cooling gas in the four axial ventilation channels is made possible. In this way, the calculated temperature rise of the generator end is significantly reduced. In order to verify the feasibility of the hybrid cooling structure, a prototype is made and type test is carried out. The test results are basically consistent with the design values, which verifies the accuracy of the design and the effectiveness of the axial ventilation channels for heat dissipation of the end windings.
The aim of the research is to design a permanent magnet generator with rated power of 300 kW and rated speed of 2 700 r/min. For this generator, the center height should be no more than 225 mm, and the power density is about 6 times that of ordinary generator. Therefore, the temperature rise control of the generator has become an urgent issue. In order to reduce the temperature rise of the generator, the water cooling frame is designed. Through the finite element simulation calculation, it is found that the temperature rise at the end of the generator winding is still high. In order to further reduce the winding end temperature rise, four axial ventilation channels are added on the basis of the raw water cooler base, and the heat exchange between the cooling water and the cooling gas in the four axial ventilation channels is made possible. In this way, the calculated temperature rise of the generator end is significantly reduced. In order to verify the feasibility of the hybrid cooling structure, a prototype is made and type test is carried out. The test results are basically consistent with the design values, which verifies the accuracy of the design and the effectiveness of the axial ventilation channels for heat dissipation of the end windings.
2020, 47(12):76-80.
DOI: 10.12177/emca.2020.154
Abstract:
Taking an offshore 6 MW medium-speed permanent magnet wind generator as the research object，the electromagnetic characteristics of the motor are simulated and analyzed for different electromagnetic schemes. The results show that the cogging torque generated by the unequal air gap skew-slot electromagnetic scheme is only 0.74% of the rated torque, and the line-voltage waveform distortion rate is 1.72%. The load characteristics and short circuit characteristics of the electromagnetic scheme can meet the requirements of product design. The air-to-air cooling scheme is adopted, and the feasibility of the scheme is verified by the analysis of temperature characteristics. According to the design scheme, two prototypes are made for test and verification. The test results of no-load voltage, no-load loss, temperature rise of stator winding and efficiency characteristics of the motor are basically consistent with the simulation analysis results, which verifies the rationality of the design.
Taking an offshore 6 MW medium-speed permanent magnet wind generator as the research object，the electromagnetic characteristics of the motor are simulated and analyzed for different electromagnetic schemes. The results show that the cogging torque generated by the unequal air gap skew-slot electromagnetic scheme is only 0.74% of the rated torque, and the line-voltage waveform distortion rate is 1.72%. The load characteristics and short circuit characteristics of the electromagnetic scheme can meet the requirements of product design. The air-to-air cooling scheme is adopted, and the feasibility of the scheme is verified by the analysis of temperature characteristics. According to the design scheme, two prototypes are made for test and verification. The test results of no-load voltage, no-load loss, temperature rise of stator winding and efficiency characteristics of the motor are basically consistent with the simulation analysis results, which verifies the rationality of the design.
2020, 47(12):81-86.
DOI: 10.12177/emca.2020.162
Abstract:
A scheme of finite control set model predictive control (FCS-MPC) is proposed for the grid-connected stability of photovoltaic and storage microgrid. The bi-directional DC/DC converter of the energy storage system adopts voltage and current dual-loop control to stabilize the DC bus voltage. Then, the discrete mathematical model of the grid-connected inverter is established, and the output current of inverter is used as the cost function control variable to construct current predictive controller. Based on the prediction of the next two steps of inverter current, the vector angle compensation method is introduced to compensate for the delay of the control process. Finally, the simulation model of photovoltaic and storage microgrid is established by using MATLAB/Simulink, and the voltage and current responses under traditional method and MPC are compared and analyzed. Simulation results show that the proposed scheme can improve the DC bus voltage stability and reduce the grid-connected current distortion rate under load changes and photovoltaic power fluctuations.
A scheme of finite control set model predictive control (FCS-MPC) is proposed for the grid-connected stability of photovoltaic and storage microgrid. The bi-directional DC/DC converter of the energy storage system adopts voltage and current dual-loop control to stabilize the DC bus voltage. Then, the discrete mathematical model of the grid-connected inverter is established, and the output current of inverter is used as the cost function control variable to construct current predictive controller. Based on the prediction of the next two steps of inverter current, the vector angle compensation method is introduced to compensate for the delay of the control process. Finally, the simulation model of photovoltaic and storage microgrid is established by using MATLAB/Simulink, and the voltage and current responses under traditional method and MPC are compared and analyzed. Simulation results show that the proposed scheme can improve the DC bus voltage stability and reduce the grid-connected current distortion rate under load changes and photovoltaic power fluctuations.
2020, 47(12):87-91.
DOI: 10.12177/emca.2020.161
Abstract:
The stator winding inter-turn short circuit fault is one of the most common faults of permanent magnet synchronous motor (PMSM). This fault will cause unbalanced three-phase currents, leading to violent fluctuation of output torque and decreasing the output capacity. When the fault is serious, excessive short-circuit current will burn the winding. In order to solve the above problems caused by inter-turn short circuit faults, a PMSM with automatic inter-turn short circuit fault tolerance has been proposed. A detection method for inter-turn short circuit fault location is proposed for this special motor. The special structure of the motor is introduced, and then the method of judging the phase of the fault coil by the characteristics of the magnetic leakage circuit and the original stator coil is deduced through the mathematical model. Finally, the finite element model of the motor is established by ANSYS software, and the simulation of different inter-turn short circuit cases of the motor verifies the correctness of the detection method.
The stator winding inter-turn short circuit fault is one of the most common faults of permanent magnet synchronous motor (PMSM). This fault will cause unbalanced three-phase currents, leading to violent fluctuation of output torque and decreasing the output capacity. When the fault is serious, excessive short-circuit current will burn the winding. In order to solve the above problems caused by inter-turn short circuit faults, a PMSM with automatic inter-turn short circuit fault tolerance has been proposed. A detection method for inter-turn short circuit fault location is proposed for this special motor. The special structure of the motor is introduced, and then the method of judging the phase of the fault coil by the characteristics of the magnetic leakage circuit and the original stator coil is deduced through the mathematical model. Finally, the finite element model of the motor is established by ANSYS software, and the simulation of different inter-turn short circuit cases of the motor verifies the correctness of the detection method.
2020, 47(12):92-97.
DOI: 10.12177/emca.2020.158
Abstract:
The switching devices of three-level NPC inverter are widely used in high-power rectifier due to the advantages of low withstand voltage level and less harmonic content of grid connected voltage. The problem of neutral point voltage balance is always the key of the topology. Through the numerical detection of charge fluctuation of two capacitors at DC side in each switching stage, after formula transformation, the time of positive and negative small vectors of traditional space vector pulse width modulation (SVPWM) is adjusted, so that the charging and discharging time of the two capacitors at the balance point can be kept consistent, and the purpose of neutral point balance control can be achieved. Simulation results show that the method can suppress the fluctuation of neutral point voltage.
The switching devices of three-level NPC inverter are widely used in high-power rectifier due to the advantages of low withstand voltage level and less harmonic content of grid connected voltage. The problem of neutral point voltage balance is always the key of the topology. Through the numerical detection of charge fluctuation of two capacitors at DC side in each switching stage, after formula transformation, the time of positive and negative small vectors of traditional space vector pulse width modulation (SVPWM) is adjusted, so that the charging and discharging time of the two capacitors at the balance point can be kept consistent, and the purpose of neutral point balance control can be achieved. Simulation results show that the method can suppress the fluctuation of neutral point voltage.
2020, 47(12):98-104.
DOI: 10.12177/emca.2020.155
Abstract:
Taking the motor rotor workshop of an enterprise as the experimental environment and taking the whole process of producing YX3-90L-2 rotor as the object, the process analysis method is used to analyze and record each process flow in the workshop, and simulation research is carried out for the workshop plane layout. A rotor workshop plane layout method is proposed, which saves 2 process flows and shortens the rotor handling distance from 546.10 m to 198.38 m. The transportation time of rotor is shortened from 1 053 s to 736 s, avoiding 5 times of cross transportation. The rotor handling distance and time are reduced, so that the rotor production efficiency as well as the production capacity of the enterprise is improved.
Taking the motor rotor workshop of an enterprise as the experimental environment and taking the whole process of producing YX3-90L-2 rotor as the object, the process analysis method is used to analyze and record each process flow in the workshop, and simulation research is carried out for the workshop plane layout. A rotor workshop plane layout method is proposed, which saves 2 process flows and shortens the rotor handling distance from 546.10 m to 198.38 m. The transportation time of rotor is shortened from 1 053 s to 736 s, avoiding 5 times of cross transportation. The rotor handling distance and time are reduced, so that the rotor production efficiency as well as the production capacity of the enterprise is improved.
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Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
沪ICP备16038578号-3
Electric Machines & Control Application ® 2025
Supported by:Beijing E-Tiller Technology Development Co., Ltd.
