Control methods of hysteresis current vector control of permanent magnet synchronous servo drive fed by voltage source inverter are examined. Detailed description of the control methods in stationary reference frame w...Control methods of hysteresis current vector control of permanent magnet synchronous servo drive fed by voltage source inverter are examined. Detailed description of the control methods in stationary reference frame with circle, square and hexagon shape tolerance area using adaptive solutions is presented. The theoretical considerations are supported by simulation results.展开更多
In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be...In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be emplayed, and especially suitable for the electrohydraulic (?)ervo-system with fast response. The simulation results show that the system given in this paper has optimal three-order system performance.展开更多
A digital controller IC for the flyback converter with primary-side feedback is proposed. The controller is used for adapter charger or LED driver applications. To obtain high accuracy for the primary-side feedback, a...A digital controller IC for the flyback converter with primary-side feedback is proposed. The controller is used for adapter charger or LED driver applications. To obtain high accuracy for the primary-side feedback, a digital primary-side sensing technology is adopted, which can auto-track the knee point of the primary auxiliary winding voltage. Furthermore, an internal digital compensator eliminates the need for external loop compensation components while achieving excellent line and load regulation. The controller could output both constant voltage and constant current depending on the load current. Pulse width modulation and pulse frequency modulation are used in constant voltage mode while quasi-resonant control is used in constant current mode. The digital controller is validated by using FPGA.展开更多
Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control （DTC） system for speeding up torque response and reducing t...Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control （DTC） system for speeding up torque response and reducing the starting current of electric screw presses and its application to the J58K series of numerical control electric screw presses with a dual-motor drive. The DTC drive system encompasses speed control, torque reference control, and switching frequency control. Comparison of the DTC dual-AC induction motor drive with corresponding AC servo motor drive showed that for the J58K-315 electric screw press, the DTC drive system attains a higher maximum speed （786 r/min） within a shorter time （1.13 s） during a 250 nun stroke and undergoes smaller rise in temperature （42.0 ℃） in the motor after running for 2 h at a 12 min-1 strike frequency than the AC servo motor drive does （751 r/min within 1.19 s, and 50.6 ℃ rise）. Moreover, the DTC AC induction motor drive, with no need for a tachometer or position encoder to feed back the speed or position of the motor shaft, enjoys increased reliability in a strong-shock work environment.展开更多
Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly,and the tension control is a key technique in fiber winding techniq...Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly,and the tension control is a key technique in fiber winding techniques.This paper introduces a closed-loop tension control system with the programmable logic controller(PLC)with function modules as its control kernel,the alternating current(AC)servo motor as execute element and the radius-following device to accomplish the real-time radius compensation.The mechanism of the tension control system is analyzed and the numerical model is set up.The compensation technique of the radius of the scroll is analyzed.Experimental results show that the system is well qualified with high control precision and high reaction speed.展开更多
The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detai...The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detailed.To solve the problem of out-of-tolerance in the system dynamic characteristics,an advanced correction network algorithm architecture and double notch filter were designed.Experimental verification was conducted to prove that the dynamic characteristics requirement under multiple operating conditions could be met.展开更多
This paper presents a design scheme of SDRAM controller based on FPGA. The paper analyze the basic operation principle of SDRAM, and introduce the state machine and the arbitration mechanism. Simulation verification i...This paper presents a design scheme of SDRAM controller based on FPGA. The paper analyze the basic operation principle of SDRAM, and introduce the state machine and the arbitration mechanism. Simulation verification in QuartuslI development environment using Verilog language show that the system achieve high-speed data caching and transmission. The design method of each module and the realization process in the overall design is introduced in detail. The experimental results show that： the controller design is flexible, stable and reliable operation, low cost. can be used as IP core for the cache system in different SOC_展开更多
文摘Control methods of hysteresis current vector control of permanent magnet synchronous servo drive fed by voltage source inverter are examined. Detailed description of the control methods in stationary reference frame with circle, square and hexagon shape tolerance area using adaptive solutions is presented. The theoretical considerations are supported by simulation results.
文摘In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be emplayed, and especially suitable for the electrohydraulic (?)ervo-system with fast response. The simulation results show that the system given in this paper has optimal three-order system performance.
文摘A digital controller IC for the flyback converter with primary-side feedback is proposed. The controller is used for adapter charger or LED driver applications. To obtain high accuracy for the primary-side feedback, a digital primary-side sensing technology is adopted, which can auto-track the knee point of the primary auxiliary winding voltage. Furthermore, an internal digital compensator eliminates the need for external loop compensation components while achieving excellent line and load regulation. The controller could output both constant voltage and constant current depending on the load current. Pulse width modulation and pulse frequency modulation are used in constant voltage mode while quasi-resonant control is used in constant current mode. The digital controller is validated by using FPGA.
基金Funded by the Natural Science Foundation of Hubei Province (No. 2004AA101E04)
文摘Fast response and stable torque output are crucial to the performance of electric screw presses. This paper describes the design of a direct torque control （DTC） system for speeding up torque response and reducing the starting current of electric screw presses and its application to the J58K series of numerical control electric screw presses with a dual-motor drive. The DTC drive system encompasses speed control, torque reference control, and switching frequency control. Comparison of the DTC dual-AC induction motor drive with corresponding AC servo motor drive showed that for the J58K-315 electric screw press, the DTC drive system attains a higher maximum speed （786 r/min） within a shorter time （1.13 s） during a 250 nun stroke and undergoes smaller rise in temperature （42.0 ℃） in the motor after running for 2 h at a 12 min-1 strike frequency than the AC servo motor drive does （751 r/min within 1.19 s, and 50.6 ℃ rise）. Moreover, the DTC AC induction motor drive, with no need for a tachometer or position encoder to feed back the speed or position of the motor shaft, enjoys increased reliability in a strong-shock work environment.
基金National Natural Science Foundation of China(50175020)
文摘Fiber winding tension is an important factor in the molding techniques of composite material which influences the quality of winding product directly,and the tension control is a key technique in fiber winding techniques.This paper introduces a closed-loop tension control system with the programmable logic controller(PLC)with function modules as its control kernel,the alternating current(AC)servo motor as execute element and the radius-following device to accomplish the real-time radius compensation.The mechanism of the tension control system is analyzed and the numerical model is set up.The compensation technique of the radius of the scroll is analyzed.Experimental results show that the system is well qualified with high control precision and high reaction speed.
文摘The 30 kW high-power electric servo system used in the solid booster of the Long March 6 A(LM-6 A)launch vehicle is introduced,and the function,composition of the system as well as its constituent equipments are detailed.To solve the problem of out-of-tolerance in the system dynamic characteristics,an advanced correction network algorithm architecture and double notch filter were designed.Experimental verification was conducted to prove that the dynamic characteristics requirement under multiple operating conditions could be met.
文摘This paper presents a design scheme of SDRAM controller based on FPGA. The paper analyze the basic operation principle of SDRAM, and introduce the state machine and the arbitration mechanism. Simulation verification in QuartuslI development environment using Verilog language show that the system achieve high-speed data caching and transmission. The design method of each module and the realization process in the overall design is introduced in detail. The experimental results show that： the controller design is flexible, stable and reliable operation, low cost. can be used as IP core for the cache system in different SOC_
