Abstract: Recuperation of braking energy offers great potential for reducing energy consumption in urban rail transit systems. The present paper develops a new control strategy with variable threshold for wayside energy storage systems (ESSs), which uses the supercapacitor as the energy storage device. First, the paper analyzes the braking curve of the train and the V-I characteristics of the s...

In low voltage low power CMOS systems the high input offset and noise voltages of MOSFETs and the moderate gain of op amps limit the accuracy of analog circuits. In this paper we summarize the results ofour recent research on the dynamic op amp matching which is a very attractive technique for the implementation of accurate analog circuits in low voltage low power CMOS systems because, in compa...

The design features of a 17 GHz chopper prebuncher injection system are described, and initial test results operating with a 500 kV low emittance electron gun and single section 17 GHz linac are presented. The 17 GHz traveling wave relativistic klystron that provides RF power to the linac structure, and the 500 kV electron gun that forms the low emittance (βγ ε = 3π mm-mradian) source for the i...

A new circuit is presented for three-phase voltage controller (AC chopper) constructed from IGBTs. Traditionally such an equipment contains thyristors as switching elements. All drawbacks of this solution come from its only possible control method: firing control. The new circuit allows Pulse Width Modulation (PWM) control, providing much better properties. A new and advantageous control method...

In this paper, chaotic behavior study of a five-cells chopper when it is associated to a nonlinear load is reported. The model of such system is described by a piece-wise smooth six dimensional non-autonomous system. Then, some basic dynamical properties, such as Poincaré mapping, first return map and continuous spectrum are investigated to highlight the main characteristic of this particular c...

A fast response radiometer and its associated instrumentation for the measurement of the temperature reached during impact is described in this paper. It is based on a thermoelectrically cooled HgCdTe detector. The sensitivity and time response have been determined by means of static calibration tests, within the range +25 to 500 "C, and a dynamic calibration using an optical chopper at 1.35 kH...