Experimental Characterization of 2 × 2 Electronically Reconfigurable Polarization Converter Unit Cells at X-Band

In this paper, an electronically reconfigurable polarization converter unit cell operating at X-band is proposed. The polarization converter unit cell consists of a passive patch, a phase shifter, and an active patch. There are two PIN diodes on the active patch. By switching the bias conditions of those PIN diodes, an electronically reconfigurable polarization converter is conceived. Both the passive and active patches are circular, and there are circular types of slots on both patches to enhance the operating bandwidth. To compensate for the capacitance introduced by PIN diodes, an equivalent capacitance structure is introduced on the active patch. 2 × 2 unit cells are designed to check the performance of the unit cell for polarization conversion applications. In addition, a novel type of experimental characterization technique is proposed to check the performance of polarization conversion using 2 × 2 unit cells. Two WR-90 waveguide sections, two rectangular to square sections, and a power supply are taken for the measurements. The rectangular to square waveguide transition section is designed in such a way so that 2 × 2 unit cells can be perfectly adjusted on the transition section and the performance of the 2 × 2 unit cells can be measured. The simulation results of the 8 × 8 array are also added to a miniaturized X-band horn antenna to check the performance of the overall array.

Analysis on the Effect of Magnetic Energy Storage on the Stability Parameters of a Wind Generator Connected System

The usage of superconducting storage medium for the improvement of system stability is studied in this paper. A Superconducting Magnetic Energy Storage coil (SMES) is used along with the wind energy connected system. The grid connectivity is maintained with the help of converter unit, controlled using fuzzy logic. The system model is simulated on MATLAB/SIMULINK environment and the variations of parameters of the generators are studied.

Software-in-the-Loop Simulation of a Gas-Engine for the Design and Testing of a Wind Turbine Emulator

In order to investigate the grid integration of wind turbines (WT) of various scales and designs, a wind turbine emulator (WTE) is being built in Flensburg within the state-funded project GrinSH. The special feature of this WTE is the use of a large gas engine instead of an electric motor to emulate the behavior of a WT. In order to develop the controls of this innovative WTE and to design the upcoming test runs under safe conditions, a software in the loop model (SILM) was applied. This SILM contained a mathematical model of the wind turbine, mathematical models of the gas engine with an integrated controller, and a model of the generator and frequency converter unit, as well as a preventive modulator of the reference signal (PMRS). The PMRS module converts the reference signal of the emulated WT in such a way that the dynamics of the engine components can be calculated and balanced in advance to enable the required behavior of the entire SILM despite the dynamics of the gas engine. It was found that the PMRS module, developed and tested in this work, increased the ability of the WTE, based on a gas engine, to reproduce the dynamics of a WT.

System of contactless automatic voltage regulation of BARN with thyristor-reactor switching device

The functional scheme of a closed system of contactless automatic voltage regulation of a converter unit with a thyristor-reactor switching device TRSD for voltage regulation is considered. The proposed external characteristics of the converter unit with the BARN and TRSD system when using the TRSNP-12500/10 converter transformer are presented. An algorithm for generating a control signal for an executive controlled thyristor – reactor switching device by the controller of the system – the SHAUN 6 cabinet-is considered, based on which the stable external characteristics of the converter are implemented on a laboratory physical model of a converter unit with a 30 kVA converter transformer.

Development of a converter unit for reading signals from a wave solid-state gyroscope with a quartz resonator

This paper describes the main principles of constructing systems for deriving information from wave solidstate gyroscopes with a hemispherical quartz resonator. A method for obtaining the necessary information by demodulating amplitude-modulated gyroscope signals is discussed. An electrical schematic diagram for the amplifier of the signal acquisition unit was developed using a domestic electronic component base. Computer simulation was carried out in the Micro-Cap environment. The prototyping was carried out, and the waveforms of the output signals of the proposed amplifier are presented.

Multifunctional converter unit with a series connection of inverters for the combined electric power system of a local object with a photovoltaic battery.

The improvement of the structure is considered and the justification of the parameters of a multifunctional converter unit with a series connection of inverters for a combined electric power system of a local object with a photovoltaic battery is performed. There are obtained dependences of the amplitude of the ripple of the output current of the inverters, the error for fundamental harmonic, and the relation for determining the values of the inverter input voltage, reactor inductance, and PWM frequency according to the mains voltage and the maximum value of the inverter current, when it combines the functions of the active power filter. The single-channel control system structure with a slave current control loop with a common channel of current deviation for inverters has been improved. The external controller is determined by the operating mode: when working in parallel with the network, it is the current (voltage) controller of the photovoltaic battery, which under current conditions has less power; in the absence of energy production - the input voltage controller of one of the inverters; in standalone mode - load voltage controller.

Coordinated Control Strategy of a Combined Converter in a Photovoltaic DC Boost Collection System under Partial Shading Conditions

Series–parallel module technology can meet a DC converter’s requirements of high-power, large-capacity, and high step-up ratio in photovoltaic a DC boost collection system. However, the cascaded structure has the problem of voltage and current sharing between modules, and due to the duty cycle limitation of converters, the combined converters in the PV-converter unit have an unbalanced voltage, which may also exceed the voltage range under partial shading conditions (PSCs). First, aiming at the problems of voltage sharing, current sharing, and low modularity in the combined converter, this paper proposes a distributed control strategy. Then, by adopting a coordinated control strategy based on the sub-module cutting in and out, the problem that the combined converter cannot normally boost under PSCs was solved. The paper not only takes the advantages of the cascade structure of the combined converter to increase the power and voltage, but also improves its modularity to solve the problem of abnormal operation under uneven irradiation. This dramatically improves the adaptability of combined converters in a photovoltaic DC collection system. Finally, a small power experiment was carried out, where the experimental results verified the effectiveness of the control strategy.

МОДЕЛЮВАННЯ КОМБІНОВАНОЇ СИСТЕМИ ЕЛЕКТРОЖИВЛЕННЯ ЛОКАЛЬНОГО ОБ’ЄКТУ З БАГАТОФУНКЦІОНАЛЬНИМ ПЕРЕТВОРЮВАЛЬНИМ АГРЕГАТОМ ФОТОЕЛЕКТРИЧНОЇ БАТАРЕЇ

The development of a detailed mathematical model of the system "network - multifunctional converter unit with a photovoltaic battery - load", which will allow for a comprehensive study of the processes in the system with an assessment of the efficiency of the unit.