Variable Frequency Speed Regulation System Research Articles

Research on Fuzzy PID Control of Concrete Press Based on Frequency Conversion Speed Regulation System

In the static compression elastic modulus test of concrete, controlling the value of the loading force is the key to the success of the test. The test requires that the set force value be reached quickly, and the fluctuation should be stable within the test standard range, even in the presence of external interference. There is no oscillation in the transient process, and the best adjustment process is achieved. This article uses a variable frequency speed regulation system to control the value of the loading force, but the hydraulic system is susceptible to fluctuations due to the influence of oil pressure and temperature. Conventional PID control cannot meet its performance requirements. As a result, this article proposes a fuzzy PID for the press’s variable frequency speed regulation system. It uses MATLAB/Simulink and the controller to simulate the system. Simulation experiments show that fuzzy PID control has a better control effect than conventional PID control.

Induction motor efficiency maximizing based on torque per power index

<span>In this paper, efficiency maximization of induction motor variable frequency speed regulation system based on torque per power (TPP) index is proposed. The detail of the mathematical model of the induction motor considering the iron loss and the rotor field orientation, the relationship between the motor torque loss power ratio and the motor speed and slip frequency presented. The functional relationship between the torque loss power ratio and the motor speed and slip is derived, and the derivative is obtained to find the optimal slip frequency corresponding to the maximum value. The simulation model and experimental platform of the control system were built in Matlab/Simulink to verify the effectiveness of the method. The result approved the torque loss power ratio takes the maximum value, the high energy efficiency operation with the minimum power loss of the motor control system is realized.</span>

Harmonic analysis of AC drive double PWM back to back network side

Aiming at the problem of harmonic pollution in the control system of large-scale steel rolling equipment in metallurgical plant, the mechanism of harmonic generation in AC-AC frequency conversion and AC-DC-AC variable-frequency speed regulation system is analyzed, and a double PWM back-to-back AC speed regulation system is proposed. This system can not only realize the regeneration energy of frequency converter, but also reduce the harmonic wave, and greatly improve the power factor of the system. Finally, through MATLAB simulation, the harmonic of AC-AC frequency conversion and AC-DC-AC variable-frequency speed regulation system is analyzed, and compared with PWM back-to-back AC speed regulation system, the superiority, effectiveness and feasibility of PWM back-to-back AC speed regulation system design for large-scale AC drive device control are proved.

Research of Harmonic Index and Testing Method Based on Virtual Instrument

In view of the practical problems such as the imperfect harmonic testing and evaluation methods of the variable frequency speed regulation system and the high operating cost, a harmonic evaluation index system including 9 indexes is established, and the calculation method of each index is clarified. At the same time, the harmonic testing and analysis method of the variable frequency speed regulation system based on virtual instruments is proposed. The Labview software platform is combined with an external data acquisition module to replace the traditional testing instruments for harmonic testing and signal acquisition, processing and analysis. On the basis of theoretical research, an experimental platform was built to conduct verification experiments, and then the application experiments of 2 working conditions were carried out. The results shows that the test method was correct and feasible. Based on the experimental results, further analysis of the impact of harmonics on the performance of the variable frequency speed control system, and the corresponding law of influence will be obtained, which will provide guidance for the subsequent development of harmonic prevention and other related work.

Integrated-Power-Control-Strategy-Based Electrolytic Capacitor-Less Back-to-Back Converter for Variable Frequency Speed Control System

This article presents an integrated power control strategy (IPCS) for a variable frequency speed regulation system, which consists of a back-to-back converter and a small film dc-link capacitor. Due to the lack of large-capacity energy storage components in the dc bus, there is a strong power coupling between the rectifier and the inverter. The dynamic response is limited and dc-link voltage oscillates because the traditional method controls rectification and inversion separately. The IPCS is proposed to achieve dynamic balance of the system power through synchronous control of the rectifier and inverter. High conversion efficiency guarantees the power balance of the rectifier and inverter meanwhile reduces the dc bus voltage ripple. To further reduce the dc-link voltage ripple and maintain the stability of the dc-link voltage under step changes of load, a virtual inertia control method is proposed, which consists of a virtual resistance control block and a virtual capacitor control block. As a result, the dc-link voltage ripple and the total harmonic distortion of the dc-link current can be improved. Simulations and experimental results are given to provide further validation of the proposed IPCS under different operating scenarios.

Design of Variable Frequency Speed Regulation and Constant Pressure Water Supply System

With the increase of population density and the improvement of human economic level, the emergence of high-rise buildings has put forward higher requirements on infrastructure such as building hydropower, traditional water supply methods have disadvantages such as secondary pollution, unstable water pressure, and high energy consumption. Therefore, variable frequency and constant pressure water supply have gradually become the main method of water supply for high-rise buildings. In order to meet the higher water supply requirements of urban residential quarters, a PLC-based variable frequency speed regulation and constant pressure water supply monitoring system is designed. The main control objective is to stabilize the water supply pressure. The inverter is driven by a three-step variable frequency control method. The pressure sensor of the water supply pipeline detects the pressure value in real time, uses the PID control algorithm, and outputs the frequency setting value to the inverter through the PLC, and then realizes the control of the water pump outlet pressure and achieves the purpose of constant pressure water supply. On the basis of considering the program capacity and expansion requirements, this system selects S7-1200 compact PLC as the main controller, uses modular programming as the basic concept to control the PID control program, logic switching program, and alarm breaking the program has been programmed and debugged. The test result shows that the designed control algorithm is effective, the logic function is complete, and it has a certain application and reference value. The frequency conversion constant pressure water supply system can realize the automatic switching of the operation status and the number of pumps in operation under different water supply requirements, and further improve the automation degree of the system on the basis of meeting the control requirements.

Application of Variable Frequency Speed Regulation Technology in Fan System

With regard to the problem in fan air volume control, the research on air volume method was carried out, and the air volume control method for frequency conversion speed regulation was adopted. In this regard, a motor variable frequency speed regulation system was designed, and a variable frequency control software was developed. In order to verify the control effect of the system on the fan air volume, a measurement experiment on the fan speed was carried out, and it was concluded that the variable frequency speed regulation method was highly precised, and had a sound linearity. While finally, this variable frequency speed regulation system was applied in the fan system, and the equal thickness collection experiment on the material was carried out in order to ensure the strict control over the air volume, which has obtained a relatively sound application effect.

A Novel Hybrid Control Method for Single-Phase-Input Variable Frequency Speed Control System With a Small DC-Link Capacitor

A novel hybrid control method, which consists of dual-frequency tracking control (DFTC) and virtual inertia control (VIC), is proposed for single-phase-input variable frequency speed regulation system with a small dc-link capacitor. Because of lacking a large-capacity energy storage device, the dc-link voltage is a pulsating dc, which causes a strong power coupling relationship between the rectifier and inverter side. The instantaneous power and dq -axis currents of the inverter contain both ac and dc components at the same time, which cannot be controlled well using traditional proportional-integrational (PI) controllers. Herein the DFTC that is based on a PI-resonant controller is proposed to accurately track ac and dc components of the instantaneous power and dq -axis currents respectively. With higher open-loop gain at both low frequency and the specified resonant frequency, the proposed DFTC ensures accurate tracking of the ac and dc components of power and dq -axis currents, high-power-factor, and low total harmonic distortion (THD) of input grid current. To maintain the stability of the dc-link voltage under step changes of load, a VIC is proposed. Subsequently, the input power factor and the fluctuation of dc-link voltage can be improved in the system. Simulations and experimental results are given to provide further validation of the proposed DFTC and VIC under different operating scenarios.

Realization of PLC to the Variable Frequency Speed Regulation System of Mine Local Ventilator based on RS-485 Communication

The article first introduces the merits of serial communication in the PLC to the variable frequency speed regulation system of mine local ventilator, and then sets up a hardware application development platform of PLC and inverter based on RS-485 communication technology, next presents communication initialization of the PLC and Inverter. Finally according to the control requirements, PLC send run operation & monitoring instruction to Inverter, realizes the serial communication control between the PLC and Inverter.

INTEGRATED PARAMETER CONTROL SYSTEM FOR DRIVING MOTOR MOBILE INTERNET

The brushless dc motor is a new kind of stepless variable speed motor, convenient maintenance, high efficiency and high performance is excellent, has on many occasions to replace other kinds of motors. Therefore, the further research of brushless dc motor has become a hot spot, has broad market prospects. In brushless dc motor as the research object, this paper designed a set of brushless dc motor based on TMS320F2812 DSP closed-loop variable frequency speed regulation system. On brushless dc motor speed control system of the basic composition, working principle, mathematical model and control strategy is commonly used, and on this basis of brushless dc motor double closed-loop control experiments, the results show that under the double closed loop control, brushless motor can run stable and reliable.

Operating characteristics of the variable frequency speed-regulating system for a single pump in a closed system

This study experimentally investigated the operating characteristics of the variable frequency speed-regulating system of a water pump in a closed system. The test data for the variable frequency water pump under various conditions were obtained by changing the water pump frequency and the opening setting of a regulator valve in the system. This study revealed that the total power ratio of the water pump system before and after the frequency adjustment did not exhibit cubic correlations with its rotational speed ratio as defined by the affinity law, especially in areas other than the high-efficiency area of pump operation. The equations that express the correlations between the frequency ratio and the total power ratio under the full range of operating conditions were obtained in this study by using the data fitting method. The test confirmed that the fitted characteristic equations had a higher precision and a wider scope of applicability than the existing equations when the water pump, motor, and variable frequency drive were considered as a whole. Practical application: The variable frequency speed-regulating system of a water pump was used in cooling, cooled and heating systems. However, the water pump power was calculated by the standard cube law, and its energy-saving potential was exaggerated. This study revealed a new energy model of a water pump system that can more accurately calculate the total power of the variable frequency water pump in practical engineering.

The Application of Fuzzy PID Control Algorithm in Variable Frequency Speed Regulation System of Glass Edge Grinding Machine

Aiming at the deficiencies of traditional PID control algorithm, the application of Fuzzy PID control algorithm is proposed in variable frequency speed regulation system of glass edge grinding machine. The design of fuzzy PID controller is presented in the paper. The paper not only introduces the system principle and models for inverter and AC asynchronous motor but also tells the principle of Fuzzy PID Controller and its design method. A simulation model including traditional PID Controller and Fuzzy PID Controller is established in MATLAB/Simulink. Through the analysis of the difference between the two controlling outputs, the better performance of Fuzzy PID Controller in response speed, accuracy and stability is proved effectively. The result can be used as important criterion to the practical application of Fuzzy PID control algorithm.

Research of AGV Variable Frequency Speed Regulation System Based on New Type PMSM

Halbach motor is a new type permanent magnet synchronous motor: unique permanent magnet structure makes its magnetic field unilateral and distributed sinusoidal, increases the magnetic density of air gap while decreases the magnetic density of rotor. It helps to raise the power density and efficiency of power, reduces the size of motor and the pulsating torque. The full-digital variable frequency adjustable speed AGV system with halbach motor based on the TMS320F2812 is designed, and its experiment result proves that it performed well and environment-friendly, saving the energy as well.

Design of Small Variable Frequency Speed Regulation System Based on ARM

This paper presents a small ARM-based frequency control system, the voltage 220V/50Hz mains, rectified, filtered into DC, then reverse into adjustable frequency alternating current supplied to the motor used. Through software algorithms SPWM control signal generated by the microcontroller, the control signal sent through the intelligent power module, the realization of the DC inverter process. The design is simple, functional and meet the current frequency control system, modular, digital trends, has a waveform, small size, high efficiency, frequency wide range of features. Has good practical value and low cost.

The Application of PSO-BP Neural Network PID Controller in Variable Frequency Speed Regulation System

Variable frequency speed control system hold good stability,more efficient,more energy conservation etc, so it has been widely used in the industrial areas,but the control strategy of traditional was difficult to achieve the desired control effect.This paper adopt particle swarm algorithm and BP neural network to construct the PID controller of PSO-BP neural network , the M-Files of PSO-BP neural network PID based on MATLAB through S-Function, and the mode of PSO-BP neural network PID variable frequency speed control system was established in SIMULINK platform.Simulation results show that the controller hold well robustness, follow and stability,and the dynamic characteristics of the original system was improved, the application value of this method in the variable frequency speed control system was proved.

Simulation and Study of SPWM Variable-Frequency Drives of Asynchronous Motors Based on Aerostatic Guide Way

The asynchronous motor is converted to a model similar to DC motor to control through coordinate transformation, and adopt SPWM inverter circuit, the motor runs with load implements ideal speed and steady operation, providing appropriate speed for aerostatic guide way. Realize simulation of asynchronous motor variable frequency speed regulation system by simulink.

Study of Optical Polishing Machine Based on Intelligent Control Technology

In order to improve control performance of polishing machine, a closed-loop Variable Frequency Speed Regulation (VFSR) System based on fuzzy control technique is designed and single-chip processor NLX230 is adopted as the control unit. Experiment result indicates that this system has the good control performance, high reliability, and producing efficiency is improved, and the product quality is also guaranteed.

Application of Variable Frequency Speed Regulation System in Coal Mine Drainage

At present,in allusion to problems of high motor energy dissipation,low reliability in the coal mine drain system of our country.The motor which is used to drag pump is controled by variable frequency speed system.The mechanical properties of down-hole pump and the principle and methods of the pump energy saving applied variable frequency speed will be expounded.Studies show that effects of the technology and energy saving is remarkable and that has a certain degree of social and economic benefits.

ARM-Based Speed Regulating System for Asynchronous Motor

Owing to their simple structure and stability, AC induction motors have been widely used in many fields. With the development of electronic devices, variable-frequency speed regulation system of the induction motor is widely used. This paper introduces an ARM chip controller LM3S818 from Texas Instruments in detail as a microprocessor of the variable frequency speed regulation system for asynchronous motor. The main circuit of AC-DC-AC Variable frequency way is adopted and the control system is based on Space Vector Pulse Width Module. The hardware structure and the design of software both are presented. And experimental results show the good performance in different frequency.

Radiation Disturbance of Variable Frequency Winch Drive System in Underground Coal Mines

In order to study the effect of variable frequency drive system upon electromagnetic radiation environment in underground coal mines, the mechanism of electromagnetic radiation from the variable frequency speed regulation system has been analyzed deeply, and the radiated electromagnetic noise from the variable frequency winch system with rated voltage of 1140V in underground coal mines has been measured. The measuring results show that the radiated emission from variable frequency drive system has certain effects on electromagnetic radiation environment in underground coal mines. The maximum radiated E-field strength reaches 123dBμV/m within the range of 9kHz to 20MHz nearby the frequency converter, and radiated E-field strength is no more than 33dBuV/m above 20MHz. Nearby the winch motor, the radiated E-field strength is weak, but the frequency spectrum of radiated E-field noises is more wide, which mainly distributes from 20MHz to 1GHz, but the maximum radiated E-field strength is less than 37dBμV/m above 20MHz.