Study On The New Asymmetric Pulse Track Circuit Technology

The asymmetric pulse track circuit, which has some advantages like the strong anti-interference ability, and the stable work performance, is widely used in the railway sections. But the track circuit has some defects all the same in the railway spot. For the code generator of the track circuit, it inclines to be damaged as the high pressure formed due to the empty loading, and for the decoder, it cannot discern the signals correctly in the environment of strong interference, sequentially making the relay not join or release reliably.This thesis researched the asymmetric pulse track circuit, focusing on the study and improvement of the code generator and the decoder, and analyzing the simulation. The research can meet the work requirements for the transmission signals in the track circuit such as the adjustment, shunting and the locomotive performance. The traditional code generator utilizes the high pressure being formed from the steady transformer, but it is likely to be saturated deeply when the generator is in the condition of empty loading. Accordingly, the new code generators are made, which use the times rectifier circuit, add smoothing filter in the current, and control the main circuit that can produce the asymmetric pulse signals with the microprocessor in order to make the code generator emit the code. These procedures were done for the considerations that the current peak appears in the actual application of switching power which cause the volt and the current to be with different phase, and the power factor to decrease. Decoder will work abnormally when it present itself in the faults. Consequently adopting the linear rectifier, zero examination, and photoelectric isolation to judge the work situation, which send the signals to the microprocessor for disposal. Taking some wrong judgments in practice into account, the thesis puts forward the circuit design with double circuit hot backup, which can switch quickly when the malfunction come forth. Based on the fact that the asymmetric pulse signals being produced from the asymmetric pulse track circuit can appear distortion in transmission because of the track shunt and the optical interference, it needs to study the more accurate, reliable and anti-jamming performance testing ways to analyze and detect the real-time signals. These problems can be solved effectively imposing the maximum characteristics of the wavelet transforming modulus to simulate, grounded on the waveform test of the wavelet analysis of asymmetric pulse signals. The results show that this method is of better applicability, simple algorithm and fast computing. Under the new asymmetric pulse track circuit, simulating the hardware circuit with Multisim to judge the feasibility of the hardware design, and analyze the software design of the main program modules, interruption subroutine modules and serial communication modules.