Low-Harmonic DC Ice-Melting Device Capable of Simultaneous Reactive Power Compensation

Abstract

As a result of the high efficiency of ice-melting and the small power supply capacity, DC ice-melting devices are widely used in relation to transmission lines in the power grid. However, it needs to consume reactive power when ice-melting, and voltage fluctuation of the substation may be caused when the demand for reactive power is large. It also generates a large number of 5th and 7th harmonics when ice-melting. In this paper, combined with the demand for ice-melting for transmission lines and the dynamic reactive power of substations, a low-harmonic DC ice-melting device capable of simultaneous reactive power compensation is studied. The function of ice-melting and reactive power compensation can be operated simultaneously and the rectifier's main harmonics can be eliminated. The simulation and experimental research on the device was carried out in the 500 kV Chuanshan substation. The actual ice melting was carried out on the 500 kV Chuansu I line and took only 68 min to melt the ice. The 500 kV bus voltage had no negative deviation, and the positive deviation decreased from +3.09% to +1.57% within 24 h of testing. The results prove the feasibility of the proposed DC ice-melting device in this paper.

DC Traction Power Supply System For Electrified Railway With Ice Melting Function

“…Among them, the uncontrolled rectifier is low cost and easy to realize large capacity devices, while the thyristorbased fully controlled rectifier can realize smooth regulation of output DC voltage. However, both of these two topologies have the problem of high input current distortion rate and need to be equipped with a large number of harmonic and reactive power compensation devices [33] . The IGBT-based fully controlled rectifier has strong output voltage regulation capability and excellent power quality, but it has high cost and complex system design.…”