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Hybrid Energy Storage
Published in Yatish T. Shah, Hybrid Power, 2021
Power electronics is the application of electronics for power conversion. A subcategory of power conversion is the AC to AC conversion. An AC to AC voltage controller is a converter which controls the voltage, current, and average power delivered to an AC load from an AC source. There are two types of AC voltage controllers: single- and three-phase AC controller. A single-phase AC/AC converter is a converter which converts from a fixed AC input voltage into a variable AC output voltage with a desired frequency. They are used in practical circuits like light dimmer circuits, speed controls of induction motors and traction motor control, etc. There are many existing technologies in single-phase AC/AC converters; they are single-phase two legs, three legs, and four legs. The single-phase two- and four-leg converters have some demerits like they need large number of power devices, large control circuitry, more switching, and losses are reduced only half to control the 50% of the output. So, to overcome these demerits present in the conventionally used converters, a better approach is the use of single-phase three-leg AC/AC converter [4].
Enhancing Power Quality with an Improved Dynamic Voltage Restorer
Published in P. C. Thomas, Vishal John Mathai, Geevarghese Titus, Emerging Technologies for Sustainability, 2020
The controller proposed in this paper brings Multi-functionality to the DVR using a single controller. It compares the load voltage with the reference voltage with the help of a Hysteresis Voltage Controller. The three phase reference voltage for the comparison is first generated virtually, the load voltage is then taken as feedback to form a closed loop. voltage fluctuations like Sag/Swell as well as Harmonics is detected through this method and corresponding gate pulses are generated to activate the inverter. The required compensation is thus made. Here the energy stored from PV solar panel serves as the backup or as the energy storage. The PV-DVR proposed here has in addition an energy conservation mode which provides the required power to the load during an outage or when the grid is unable to supply the required power to the critical loads connected which adds an additional feature to the DVR. Fig. 37.2 shows the circuit diagram of the proposed DVR.
Control of modified flotation columns by computer
Published in Gülhan Özbayoğlu, Çetin Hoşten, M. Ümit Atalay, Cahit Hiçyılmaz, A. İhsan Arol, Mineral Processing on the Verge of the 21st Century, 2017
B. Öteyaka, O. Parlaktuna, A. Pirinç
The control of pumps is accomplished using a closed-loop control system. The reference voltage for the optimum speed of the pump is compared with the voltage produced by the speed-measuring sensor. If the measured voltage is less (greater) than the reference voltage, controller increases (decreases) the applied voltage to the motor and motor speeds up (slows down). This control action keeps the speed of the pumps about the optimum values.
ITBC Controlled IPWM for Solar Based Wide Range Voltage Conversion System
Published in IETE Journal of Research, 2023
Therefore, the proposed controller is used to control both modes. The control technique of the proposed converter is shown in Figure 6. In an energy storage system (ESS), energy management is used to change modes of operation. If reference value idcref is greater than zero, then the proposed converter operates in DC–AC mode or in rectifier (AC–DC) mode of operation. The DC current controller magnitude of the reference current is denoted as (idcrefm). A DC voltage controller is employed to avoid overcharging or discharging. Gdc generates the UL (upper limit) of IG and prevents overdischarge; Vdcrefm is limited by the controller to prevent overcharge. UPF is got from PLL (phase locked loop), which matches system frequency with grid frequency. Reference grid current is given in (21) inner controller, match Vgrid, and get correction of power factor.