Scientific Journal of KubSAU

In agricultural production, the direction of introduction of renewable energy for power consumers remote from the external electrical network is relevant. Here, prospects are revealed in front of the solar PV stations. One of the main functional units of solar power is inverters that convert the DC voltage of the solar panels into alternating current. The article describes the advantages and disadvantages of the main methods of voltage regulation of the autonomous inverters of solar photovoltaic power plants. We have proposed new structural designs of autonomous voltage inverters, described their advantages, features of design and operation for voltage stabilization. We suggest stand-alone inverters designed using high frequency link, which will significantly improve mass and dimensions parameters of the converter. Due to the use of single-phase transformer with a rotating magnetic field in stand-alone inverters, we improve the efficiency of the converter and the reliability of the work. Patents of the Russian Federation confirmed the novelty of technical solutions of the considered schemes of autonomous voltage inverters. Structural schematics of the voltage regulators considered in the article, as well as features of their work, will allow to increase efficiency of preliminary works on development of autonomous voltage inverters with improved operational and technical characteristics for solar photovoltaic power plants

In the article we have considered the technical solutions of voltage regulators and the frequency of current of the asynchronous generators of the wind power installations executed with the help of the direct frequency transformers. The comparative analysis of them has been carried out as well

A promising is currently the use of asynchronous generators with capacitive excitation as a source of electricity in stand-alone power systems. Drive asynchronous generators may exercise as a thermal engine and wind wheel wind power plant or turbines of small hydropower plants. The article discusses the structural and schematics of voltage stabilizers and frequency of asynchronous generators with improved operational and technical specifications. Technical novelty of design solutions of the magnetic system and stabilizers asynchronous generator of electricity parameters confirmed by the patents for the invention of the Russian Federation. The proposed technical solution voltage stabilizer asynchronous generators, can reduce the weight of the block capacitors excitation and reactive power compensation, as well as to simplify the control system power circuit which has less power electronic devices. For wind power plants it is an important issue not only to stabilize the voltage of the generator, but also the frequency of the current. Recommend functionality stabilizer schemes parameters of electric power made for direct frequency converters with artificial and natural switching power electronic devices. It is also proposed as part of stabilization systems use single-phase voltage, three-phase transformers with rotating magnetic field, reduce the level of electromagnetic interference generated by power electronic devices for switching, enhance the efficiency and reliability of the stabilizer.

Synchronous generators are the primary source of electrical power autonomous electrosupply systems, including backup systems. They are also used in a structure of rotating electricity converters and are widely used in renewable energy as part of wind power plants of small, mini and micro hydroelectric plants. Increasing the speed and the accuracy of the system of the voltage regulation of synchronous generators is possible due to the development of combined systems containing more stabilizers. The article illustrates the functional schemes of circuit voltage stabilizers and frequency synchronous generators (with electromagnetic excitation and permanent magnet excitation) and describes the features of their work, including two and three-aggregate rotating converters of electricity used in uninterruptible power supply systems. To improve the technical characteristics of the system of stabilization we have proposed functional solutions for stabilizers of synchronous generators made on the base of direct frequency converters and using a transformer with a rotating magnetic field. To improve the reliability of and to improve the operational characteristics of the autonomous independent sources of electricity we suggest creating the main functional blocks and the elements of the stabilization system in a modular way. The functional circuit solutions of voltage regulators of synchronous generators and the characteristics of their work considered in the article, are able to improve the efficiency of pre-design work in the development of new technical solutions for stabilizing the voltage and the frequency in synchronous generators of electrosupply autonomous systems