The burn-in test of three-phase UPS by energy feedback method
In the burn-in test of three-phase online uninterruptible power supply (UPS) system, RLC is usually used as a load in the conventional method. For saving energy and decreasing the test cost of UPS, the energy feedback method is proposed to apply the test of the online UPS. In this method, the utility system is used instead of a load. A voltage regulator is used in parallel operation to turn back the energy, which was dissipated in conventional method, to the utility system. The values of real power and reactive power in the output of UPS can be regulated in the proposed method to imitate various loads. From the experimental results, the efficiency of saving energy is more than 85% near half-load and will be higher while the load increases.<<ETX>>
Design of a digitalized burn-in test plant
A burn-in test plant with multiple inputs having a wide range of input voltages is proposed herein, whose controller is realized by a digital signal processor (DSP). By means of DSP, data monitoring and command setting are easy to realize. First of all, the details of the proposed circuit topology and the corresponding control strategy are presented, and secondly some experimental results are provided to verify the proposed burn-in test plant.
Kinemamtic analysis of flying-saw vehicle
The paper analyzes the kinematic motion of the flying-saw vehicle.After the analysis,it is concluded that the ac- celerating periods and decelerating periods in both forward and backward directions will follow sin~2αcurve and,in order to increase the sawing dimensional accuracy,flying-saw vehicle must come back as soon as possible while acceleration remains constant.Based on this premise,the paper gives out the equations of kinematic motion of the flying-saw vehicle in every sta- ges and one example result in a common situation.By now this method has been used in the real situation.