Abstract: In order to make high-voltage transmission line anti-icing without interrupting power supply, OLTC anti-icing devices can be used for reducing the line voltage and increasing operating current to undermine the conditions of icing formation. The relevant relay setting values of the anti-icing line needs to be modified accordingly. In this paper, the research on how to reset the value of the 110kV and 220kV lines had been done after the OLTC equipment was implemented, and the principle of relay protection setting related to the change of line operating voltage and current had been given. A digital simulation of an area which encountered the icing disaster in 2008 had been done and the results shows that the reset relay protection setting of relevant relay protection is reasonable.
Abstract: A novel islanding detection method based on Power Controlling is presented in this paper. The method continuously perturbs the reactive power supplied by dispersed generation systems while simultaneously monitoring the point of commoncoupling (PCC) voltage and frequency. When in grid-connected scenario, the voltage and frequency of PCC is insignificant; however, once the islanding event takes place, the frequency of PCC will be change own to the change of output reactive power. After it is over 4 cycles continuously, then the active power of dispersed generation systems is reduced to 80%, now a drop in voltage positively confirms islanding. Algorithm of the method is simple and confirmed by simulation with MATLAB.
Abstract: The stabilization problem of singular linear large-scale control systems with output feedbacks is investigated by using the generalized Lyapunov matrix equation, system decomposition method, singular systems theory and matrix theory. Some sufficient conditions for determining the asymptotical stability and unstability of the corresponding singular closed-loop large-scale systems are given. At last, an illustrate example is given to show the application of main result.
Abstract: Aiming at the problems such as switch impulsion, insurmountability for influence caused by nonlinearity in one tank gun control system which adopts double PID controller to realize the multimode switch control between high speed and low speed movement, the system math model is built up; And then, Model Reference Adaptive Control (MRAC) method based on nonroutine reference model is brought in and the adaptive gun controller is designed. Consequently, the compensation of nonlinearity and multimode control are implemented. Furthermore, the Tracking Differentiator (TD) is affiliated to the front of controller in order to restrain the impulsion caused by mode switch. Finally, the validity of control method in this paper is verified by simulation.
Abstract: For the problem that manual adjustment of the parameters of controller in sensorless control system costs too much time, manpower and always can not get a good result, a new method based on improved particle swarm optimization algorithm is proposed to optimize the parameters. The improved algorithm is based on the standard particle swarm optimization with the simulated annealing algorithm and chaotic search brought in. The speed of motor is estimated by the extend Kalman filter. The error between measured speed and estimated speed of the permanent magnet synchronous motor rotor is used as the fitness function in order that the parameters in the covariance matrix is adjusted.The result of simulation indicates that high estimation precision can be got and the motor represents steadily with few of ripple of the actual speed.With this method, the time of adjustment is reduced and manpower is saved. In addition, the validity of the method is proved in experiment with dSPACE.
Abstract: Along with the industry and the motor control system performance and the intelligent request's unceasing enhancement, the PID control technology application is getting more and more widespread. This article use TMS320F2812 DSP of TI is a core, outside expands SRAM. This system control actuation closed loop direct current machine by the F2812, DSP controls electrical machinery's rotational speed and the direction through CPLD. It control electrical machinery's rotational speed by PID algorithm reaction. This system realized TMS320F2812 not to brush electrical machinery's control regarding the cocurrent, the main characteristic uses the digital PID controller, the original simulation PID controller hardware will realize the function realized with the software, it with simulated the PID controller to compare the merit is: Has the very strong flexibility, may test and experience the online adjustment parameter according to the experiment, may obtain the better control performance.
Abstract: Based on the variable stiffness elastic principle, completed three series of variable stiffness elastic suspension system design for the ocean pipe laying tensioners, effectively improved the clamping ability of the tensioner when the local pipe diameter is changing, and improved the overall stress environment of the tensioner. Established non-linear mathematical model and got the impact of instant response and response force by using the Matlab software.
Abstract: A four-channel sensor durability to intermittent operation of motorcycle test system was given based on LabVIEW. The system provides a good working platform and a Convenient testing tools for the four channels of sensor signal data acquisition, signal analysis and processing. The hardware is composed of four-sensor platform, oscilloscope, servo motor, calibration, and computer. The system operating interface is designed using LabVIEW. The results show that the system could achieve the continuous automatic motor stopping, turning control, it could also sample four channel signals and analysis of the measurement data, automatic judge, real-time display. Compared with the traditional testing method, which saves cost and improves testing efficiency.
Abstract: Aiming at that superheated steam temperature system exists the large inertia and large time delay of the dynamic characteristics,and the converge speed of the conventional CMAC neural network is not fast enough to the real-time system, a credit assignment CMAC (CA-CMAC) neural network control is adopted in superheated steam temperature control system, which is proposed to speed up the learning process in CMAC. The simulation of the superheated steam temperature control system shows that CA-CMAC converges faster than the conventional CMAC. This result illustrates the effectiveness of this method.
Abstract: With the discovery of abundant gas hydrate storage, the natural gas will become an important fuel for future vehicles. In order to improve the starting performance of the CNG engine, an electrical control system was developed and the starting control mode was set up according to the engine operating characteristics. The control parameters of injection quantity, injection timing, ignition energy and ignition timing were considered in the model. The tests of start and idle were conducted on a four stroke CNG engine. The results indicated that the CNG engine can start faster and more reliably by using the optimal start control strategy.