In this paper, a new linear quadratic regulator (LQR) and proportional integral (pi) hybrid controlalgorithm for a permanent-magnet synchronous-generator (PMSG) horizontal-axis wind turbine was developed and simulate...
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In this paper, a new linear quadratic regulator (LQR) and proportional integral (pi) hybrid controlalgorithm for a permanent-magnet synchronous-generator (PMSG) horizontal-axis wind turbine was developed and simulated. The new algorithm incorporates LQR control into existing picontrol structures as a feed-forward term to improve the performance of a conventional picontrol. A numerical model based on MATLAB/Simulink and a commercial aero-elastic code were constructed for the target wind turbine, and the new control technique was applied to the numerical model to verify the effect through simulation. For the simulation, the performance data were compared after applying the pi, LQR, and LQR-pi control algorithms to the same wind speed conditions with and without noise in the generator speed. Also, the simulations were performed in both the transition region and the rated power region. The LQR-pialgorithm was found to reduce the standard deviation of the generator speed by more than 20% in all cases regardless of the noise compared with the pialgorithm. As a result, the proposed LQR-picontrol increased the stability of the wind turbine in comparison with the conventional picontrol.
The coordinated operation of open canal water delivery and distribution systems is fundamental for achieving safe, reliable, efficient, timely, and economical water supply in irrigation districts. In the past, the pro...
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The coordinated operation of open canal water delivery and distribution systems is fundamental for achieving safe, reliable, efficient, timely, and economical water supply in irrigation districts. In the past, the processes of water delivery and distribution were usually loosely connected, making it difficult to achieve synergistic regulation of both. To solve this problem, this paper establishes the coupled model of canal optimal water distribution and canal control, which realizes the synergistic coupled regulation of water delivery and distribution scheduling under different water supply flow rates. The model initially allocates a water distribution scheme, and then adjusts the water distribution scheme through the hydraulic calculation for the uniform flow area and the backwater area of the canal pool. It subsequently determines the target water level and realizes the coordination and cooperation between the revised and optimized water distribution scheme and the check gate scheduling. Additionally, it scientifically formulates the regulation strategy of the delivery and distribution scheme under different scenarios. The coupled model is applied to the Bojili irrigation district. The results show that the coupled model provides the target water levels, water distribution schemes, and scheduling schemes under three kinds of water supply flow rates of large, medium, and small. It realizes the comprehensive objectives of reducing the frequency and amplitude of gate regulation, minimizing water shortage or oversupply, and the safe operation of the canal. The research results can provide diversified water distribution and regulation schemes for irrigation districts, which have strong practicability and guiding value.
Distributed power supply system has the advantages of energy saving, environmental protection, high reliability, high stability and so on. The combined cooling, heat and power (CCHP) system based on gas turbine is a d...
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Distributed power supply system has the advantages of energy saving, environmental protection, high reliability, high stability and so on. The combined cooling, heat and power (CCHP) system based on gas turbine is a distributed energy supply system which adopts the strategy of power cascade utilization. It can provide electric power, air conditioning chilled water and domestic hot water at the same time. In this paper, the construction scheme of the CCHP system based on gas turbine is proposed firstly. Afterward, a comprehensive dynamic model of the CCHP system based on gas turbine is established. The model consists of four mutually coupled sub-models. Then, the controller of the CCHP system is designed. In the operation mode of "electricity determines cold and heat", three sets of pialgorithm with feedforward compensation are adopted to ensure the stability of combustion engine speed, temperature of chilled water outlet and domestic hot water outlet. Finally, a HIL simulation test of the CCHP system based on gas turbine is carried out. The test results show that the speed overshoot does not exceed 0.5% when the gas turbine is unloaded. The temperature of chilled water outlet of bromine cooler can achieve stable control. The temperature of domestic hot water outlet has a small overshoot and no steady state error. Therefore, the correctness of the controlalgorithm, the feasibility and effectiveness of the controller are verified.
Purpose This study aims to focus on the grid connected inverter. Design/methodology/approach The grid connected inverter for harmonic suppression was designed, the topological structure of the inverter and the design ...
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Purpose This study aims to focus on the grid connected inverter. Design/methodology/approach The grid connected inverter for harmonic suppression was designed, the topological structure of the inverter and the design of LCL filter were analyzed, then a piR controller was proposed and finally simulation and experiment were carried out. Findings The simulation results showed that the distortion rates of the 5th, 7th and 11th harmonics under piR control were 0.14%, 0.13% and 0.06%, respectively, which were significantly lower than that under picontrol. The system test results also showed that the current waveform under picontrol was rough and total harmonic distortion (THD) content was 3.8%;under piR control, the grid connected current waveform was relatively smooth, with fewer spikes and burrs, and the THD content was 1.9%, indicating that the harmonics were effectively suppressed. Originality/value The experimental results verify that the inverter and piR controller designed in this study are effective for harmonic suppression. This work makes some contributions to the improvement of the effect of harmonic suppression and promotion of the better application of grid connected inverter.
Ultrasonic wireless power transfer (UWPT) is a reasonable method to power loads in enclosed metal container. For the existing open-loop UWPT system, the output voltage varies with different loads. In this paper, a clo...
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ISBN:
(纸本)9781728133980
Ultrasonic wireless power transfer (UWPT) is a reasonable method to power loads in enclosed metal container. For the existing open-loop UWPT system, the output voltage varies with different loads. In this paper, a closed-loop UWPT system with constant output voltage for different load resistances is proposed. Two pairs of piezoelectric transducers with different resonant working frequencies are adopted, for which one pair is used for power transfer and another is used for voltage signal feedback. pi control algorithm is used to dynamically adjust the PWM duty of the boost circuit, which is able to regulate the input voltage of the high-frequency inverter. As a result of which, the output voltage of the system can be kept constant when the load resistance varies. The experiment validates the proposed system.
Aiming at reducing the waste of electric energy by traditional electronic load, this paper studies the feed-back single-phase AC electronic load which can effectively reuse the electric energy to achieve the energy re...
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ISBN:
(纸本)9781538671740
Aiming at reducing the waste of electric energy by traditional electronic load, this paper studies the feed-back single-phase AC electronic load which can effectively reuse the electric energy to achieve the energy reutilization. Based on the "back to back" H-bridge with fully controlled devices, the basic working principle of the whole system is analyzed. The deficiency of traditional pi control algorithm and the advantage of quasi-PR algorithm are studied. In the MATLAB simulation, the PR controlalgorithm on the control effect is verified and analyzed. The pi and the quasi-PR controlalgorithm are combined and applied in this paper. The simulation and experimental results verify the feasibility of the control strategy.
Based on research of the robot car's motion control system,TMS320 f2811 chip which produced by Texas Instruments(TI) was used as the core chip of the control *** to design the control circuit of robot car was illu...
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ISBN:
(纸本)9781509046584
Based on research of the robot car's motion control system,TMS320 f2811 chip which produced by Texas Instruments(TI) was used as the core chip of the control *** to design the control circuit of robot car was illustrated in this paper from hardware part and software *** design of motion control system for robot car based on DSP technology and integrated-separated pi control algorithm was put forward,which guarantee the control accuracy and improve the real time *** is proved by practice that this scheme of design is effective for the robot car's motion control system.
The paper addresses the control problem of a binary distillation processes. There are analyzed the quality specifications of separated products and also the distributed and multivariable character of the process. The ...
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ISBN:
(纸本)9781479984817
The paper addresses the control problem of a binary distillation processes. There are analyzed the quality specifications of separated products and also the distributed and multivariable character of the process. The robustness of the control system lies in its simplicity versus the investment. The paper presents the studies made for development and numerical testing of three types of control structures for propylene-propane separation process: the feedback control structure, the feedforward control structure and the optimal control structure.
To reduce the effect of servo lag error in the close-loop adaptive optics system (AOS), a prediction controlalgorithm (PCA) is proposed in this paper. We describe a linear predictive controller that uses the historic...
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To reduce the effect of servo lag error in the close-loop adaptive optics system (AOS), a prediction controlalgorithm (PCA) is proposed in this paper. We describe a linear predictive controller that uses the historical voltages of deformable mirror to predict their future voltages in advance. The parameters of the predictor are optimized in real time by a modified Recursive Least-Square (RLS) algorithm. Numerical simulations are carried out to show the significant improvements brought by the predictor. The close-loop Strehl Ratio of the residual wave-front error and the power spectrum density of the residual voltages of deformable mirror are calculated as the evaluation criterions. The comparison results between the PCA and the classical proportional integral (pi) controlalgorithm show that the residual errors caused by servo lag in the system could be more effectively reduced by using the PCA than using the classical pi control algorithm. In addition, the control bandwidth of AOS is improved by using the PCA.
Using an appropriate control method, linear ultrasonic motors can be used in applications requiring high position accuracy. In this paper, a closed loop picontrol system is designed to achieve high position accu-racy...
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Using an appropriate control method, linear ultrasonic motors can be used in applications requiring high position accuracy. In this paper, a closed loop picontrol system is designed to achieve high position accu-racy during the control of a two-DOF stage driven by linear ultrasonic motors, Two ultrasonic motors are mounted on the stage to generate motion in two ortho-gonal directions. The pi control algorithm is used to increase the stability and accuracy of position control. The x-axis mover covers 30 mm forward and backward in less than 0.3 s settling time and the y-axis mover in less than 0.4 s. Experimental results denote that the control strategy proposed in this paper appears to have high effi-ciency, quick response, and high accuracy.
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