Arc voltage testing device of pantograph catenary system

Abstract

The invention discloses an arc voltage testing device of a pantograph catenary system. The device consists of a parallel resistance capacitive-type voltage divider, an isolation amplifier, a data acquisition card and a computer, wherein the parallel resistance capacitive-type voltage divider acquires a potential of a catenary system during off-line of the pantograph catenary system and a potential of a current-collecting pantograph sliding plate respectively, and then inputs the potential difference of the two voltage division points to the isolation amplifier for performing isolation amplification, the data acquisition card collects a voltage outputted from the isolation amplifier after isolation amplification and transmits the voltage to the computer, and the computer processes the voltage to obtain the arc voltage of the pantograph catenary system. The arc voltage testing device has strong anti-jamming capability, increases the range of tested frequency band, reduces the phase difference, and can accurately measure the arc voltage of the pantograph catenary system.

Description

technical field [0001] The invention relates to a pantograph-catenary arc voltage testing device, which belongs to the technical field of electrified railway system measurement. Background technique [0002] High-speed railway is the trend of railway development in the world today, and increasing the speed of train operation is the goal that countries all over the world are constantly pursuing. However, with the increase of train speed, the pantograph-catenary (pantograph-catenary) offline phenomenon is caused by various factors such as the irregularity of the catenary wire, the vibration of the catenary and pantograph head, and the irregularity of the track. More and more serious, pantograph-catenary arc will be generated when pantograph-catenary offline. The pantograph-catenary arc will ablate catenary wires and pantograph slides, and generate overvoltage and high-frequency noise at the same time, seriously affecting the driving safety of locomotives. Therefore, it is ne...

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Problems solved by technology

Among them, the voltage transformer uses the electromagnetic coupling principle of the magnetic core to realize the signal extraction. Although this method can extract the main waveform of the arc voltage, it has the following defects due to the influence of the measuring instrument and the field environment: (1) Influenced by factors such as response speed, leakage flux between windings, and distributed capacitance, the measurement bandwidth of the voltage transformer is relatively narrow, while the frequency spectrum of the arc voltage signal is widely distributed (up to dozens or even hundreds of megahertz), so this method It will suppress some frequency band signals of the arc voltage, and cannot fully reflect the characteristics of the arc voltage; (2) In the process of pantograph-catenary arcing, strong electromagnetic radiation will be generated, and the electromagnetic environment of the measurement site is harsh, and the voltage transformer mostly adopts the principle of electromagnetic coupling For signal extraction, the radiated interference signal is easily superimposed on the output signal through electromagnetic coupling, which distorts the arc voltage waveform

However, at high frequencies, due to the influence of distributed capacitance, distributed inductance and other factors in the resistor divider, its response bandwidth is limited, and there will be a phase difference between the measured voltage and arc current, making it difficult to judge the arcing point

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