In this paper the process of transient analysis of synchronous generator is analyzed when the load is switched. After the load changed, the excitation response curve of mobile station is obtained via matlab simulation, which provides a theoretical basis for excitation control of the mobile station, then can be helpful for optimizing the motor running and the design of motor protection.

The AC electronic load circuit is studied, PWM converter is used in this circuit in order to achieve the simulation function of load characteristics.The methods of how to get the command current mathematical model and simulation module is given which is based of the Matlab/Simulink platform, Hysteresis control mode is used in order to get fast and stable actual current and then carried on the simulation of the proposed electronic load. The simulation results show that the proposed algorithm and the control instruction current method and the effectiveness of the current control method, realized the simulation of ac electronic load.

One of the most important parts in the energy feedback electronic loads is the grid-connected inverter, and its function is to feed the detected electrical energy back to the grid for saving energy. In this paper, the principe of the grid-connected inverter is elaborated, then the PI control and the LCL filter are selected, the mathematical model was set up and the feed forward control voltage was added that suppressing the influence on the system produced by the grid disturbance. The simulation was conducted with the help of Matlab/Simulink, from the simulation waveforms it can be seen that the system dynamic and static performance was good, meanwhile electrical energy can be fed to the grid in the way of unit power factor, eventually the feasibility and superiority of the designing scheme is confirmed.

Abstract. In consideration of low power density of electric excitation claw-pole synchronous alternator (EECA) and some difficulties in magnetic field regulation of permanent magnet claw-pole synchronous alternator (PMCA), a novel hybrid excitation brushless claw-pole alternator (HEBCA) is proposed in this paper. Its structure and field control principle are described. Three dimensional finite element analysis is used to obtain the no-load magnetic field distributions and field control capability under different field currents. The result shows that the flux of the prototype machine can be adjusted over a wide range with a relatively low field current.

In order to research the crosstalk of multiconductor cable’s different core lines, based on finite-difference time-domain (FDTD) method, the Crosstalk of the four core lines cable without metal shield layer is researched by simulation. Results show that because of the cable’s distributed parameters, the far end voltage of disturbing core line is smaller than near end voltage, the voltage of disturbed core lines is smaller than that of disturbing core line evidently. But when cable is working in thunder and rain, the grounding line of the cable may induce very high voltage, and the high voltage may disturb the core lines of cable that used to transfer useful signals, so the crosstalk can’t be neglected. Experiment is done with four core lines cable without metal shield layer that lay on the earth. Experimental and simulation results are nearly same, which are compared. Because of the influence of experimental loss waste, wire connection and so on, voltage got by experiment is smaller than that got by simulation. Results show that FDTD method is effective in analyzing the influence of the lightning voltage signal.