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Recently, the danger of a long blackout is discussed in Europe. Blackouts can be caused by failures in the energy distribution, errors in large power plants or even cyber-attacks. This can lead to a chain reaction and a disintegration of the mains. Longer blackouts have an extreme impact on the economy as a whole and on local households. Therefore, a small local grid at home which can supply the most important loads over some time has garnered increasing interest. With a small direct current (DC) grid, critical loads such as for deep freezers and refrigerators can be supplied, and some LED lights can be used in the evening or at night. Solar generators (panels) can be used to charge energy storage devices, e.g., batteries. A DC grid can not only be used in the case of an emergency, but can also be used to reduce energy consumption out of the public mains and reduce energy bills. The architecture of the household emergency DC grid is discussed; suggestions for batteries are given; two simple chargers, based on DC-DC-converters like the Buck (step-down) and on the Boost (step-up) converters, are shown; dimensioning suggestions are given; and simple, robust controllers, a P-controller with disturbance feedforward and a hysteresis controller, are treated and tested via simulations. The goal of the paper is to show a simple autonomous home energy system without an external fieldbus, LAN or internet connection with special focus on simple charger topologies. [ABSTRACT FROM AUTHOR]

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In this paper, a single-phase switch-mode buck-type AC-AC voltage regulator is presented with reduced numbers of elements which are used in the topology. Apart from similar studies in the literature, a new hybrid control method which is structured by the closed-loop PID controller and a new enhanced feedforward controller is used for the control of the regulator. The hybrid controller improves the active tracking capability of the reference to achieve an output voltage as close to the sine-wave with high quality. The input AC voltage may be an ideal sine wave or it may include harmonics. Both simulation and experimental tests are applied for the proposed regulator controlled by this control method. The experimental set-up for the regulator is designed for 0-200 Vp input voltage (50 Hz), 0-100 Vp output voltage, and 0.6 kW output power. The results proved the capability of the proposed buck-type switch-mode regulator to achieve the requested output voltage as near as possible to sine wave. The obtained output voltages for different load conditions and input-output parameters have less than 5% THD (total harmonic distortion) and high quality. [ABSTRACT FROM AUTHOR]