The Resonant Power Transmission System

Introduction

The amount of electricity generated from renewable energy sources can not be constant and depends on external environmental conditions. In this case, the voltage produced for the same reason is variable.

The operating voltage of solar power plants is in the range of 24 ... 900V DC. Therefore, in order to be used with standard electrical equipment, it must be converted to alternating voltage 220 / 380V, 50 or 60Hz, and to transmit it for a distance of more than 1000m, the voltage obtained must be increased to 6-10 kV, and then the consumer must again be reduced to 220 / 380V. Thus, before the voltage goes to the consumer, it is converted three times.

This is also a problem when transmitting electricity from wind farms with a rated output voltage for installations up to 100 kW is 12-460V, DC or AC.

Reduce the number of voltage transformations, while increasing the distance from the generating unit to the consumer up to 5-10 km, by combining it with the resonant system of electricity transmission developed by us.

During the operation of power transmission lines, three leading types of power supply networks were identified:

• 1.

  AC low voltage low frequency networks (LFAC 15-60Hz, the most common is 50 / 60Hz);

• 2.

  DC networks (DC, DC lines);

• 3.

  High-frequency networks (HFAC, HFAC) (0.4-20kHz, the greatest distribution is 400 / 2400Hz).

More than 100 years ago, the inventor N. Tesla proposed to use a resonant single-wire transmission system for electricity transmission (Nikola Tesla 1897) based on two resonant transformers and a transmission line operating at a common resonant frequency. At the same time, the transmitting and receiving transformer was grounded, and the machine HF generator was used as an energy source (Figure 1).

Figure 1.

Single-wire power transmission system N. Tesla.

With the development of modern technologies and element base, it became possible to reproduce this invention at the modern level (our patent 2 255 406 of August 27, 2004). The development of resonant systems of transfer of electric energy in 1991, Russia was engaged in such scientists as Avramenko, Strebkov, Nekrasov, Trubnikov, Roshchin and others.

Figure 2.

One-wire power transmission system of the All-Russian Scientific Research Institute of Electrification of Agriculture.

1 - frequency converter; 2 - resonance circuit of the step-up transformer; 3 - single-wire line; 4 - resonant circuit of the step-down transformer; 5 - rectifier-inverter; 6 - load

The principle of operation of a single-wire resonant transmission system (Yuferev L.Yu., Strebkov DS, Roshchin O.A. 2010) is based on the use of two resonant transformers with a frequency of 5 ... 15 kHz and a single-wire line between them (Figure 2) with a line voltage of 1 ... 10 kV when operating in resonance mode.

Background Resonance transformers consist of a power resonant circuit and an up / down winding.

In the resonance circuit, the reactive energy is exchanged between the capacitor and the inductor of the circuit. During the oscillation process, the energy of the electric field of the capacitor is converted into the energy of the magnetic field of the coil, and then the reverse process occurs.

In a resonance single-wire transmission line, the voltage and current are phase-shifted relative to each other by a different angle, depending on the transmitted power (Figure 3), it is assumed that this reduces the energy losses in the transmission line.

Figure 3.

Shift between voltage and current at active power of 0, 1500 and 3000 W while the reactive power 10000 VA