 
 <prompt> Fit supply steady power without dey use plenty ungrounded wires? Given di last question, write one context wey contain di answer. E fit be 1 - 20 sentences. Context: <response>: ```But di railway operators dey interested for DC wey dey use higher voltages pass wetin dem bin dey use before. DC dey get less loss pass AC for di same voltage, and na why high-voltage direct current dey already use for some bulk power transmission lines. DC no get electromagnetic radiation wey dey come with AC, and for railway e dey reduce interference with signalling and communications and e dey reduce di risks wey dey related to EMF. DC also no get di power factor wahala wey AC get. Wetin dey interest railroading pass be say DC fit supply constant power with just one ungrounded wire. Constant power with AC dey need three-phase transmission with at least two ungrounded wires. Another important thing be say mains-frequency 3-phase AC need to dey carefully planned to avoid unbalanced phase loads. Some parts of di system dey get supply from different phases based on di assumption say di total loads of di 3 phases go balance. For di phase break points between regions wey get supply from different phases, long insulated supply breaks dey needed to avoid dem from shorting out by rolling stock wey dey use more than one pantograph at a time. Some railroads don try 3-phase but di plenty complexity wey e get don make single-phase to dey standard practice even though e dey interrupt power flow twice every cycle. An experimental 6 kV DC railway bin dey built for Soviet Union.``` 