Test results of resonant single wire system transmitting power to the infrastructure objects of the JSC “RZD”

Abstract

The paper provides test results of pilot sample of resonant single wire transmission system to a distance of 2000 m at a higher frequency. Cable power lines used as the power line based on coaxial cable. Operating principle of resonant single-wire transmission system is based on the use of two resonance transformers with frequency of 5–15 kHz, wire line voltage between the line is 1–10 kV when operating in a resonant mode. Resonant power transformers consist of a resonant circuit and step-up/step-down winding. Resonance system for high efficiency energy transfer system when adjusting all parameters at certain voltage, frequency and load. With the set of equipment, which operates at a frequency of 7–9 kHz and at a voltage of 980 V, power line can transmit electricity on a single transmission line up to 3000 watts.

The article describes the possibility of applying a resonant sin-gle-wire power transmission system at a frequency of about 7 kHz for the transmission of electric power up to 3 kW from a stationary power supply system (three-phase voltage is 380 V AC, 50 Hz) for single-phase load, and earthed on the individual earthing inverter.

Efficiency of resonant single-wire electric power transmission system increases with increasing load capacity. It can reach 88–91 % directly at the maximum load with efficient conversion equipment.

Measurements of electromagnetic fields from unscreened power lines were carried out. The results of the measurements show that the maximum value of the alternating electric field in the frequency range of 2–400 kHz is 100–150 V/m, well below the maximum permissible level. The advantage of the resonance system compared to a single-phase system is in operating at the frequency of 7 kHz.