scholarly journals Study of Energy Compensation Techniques in Photovoltaic Solar Systems with the Use of Supercapacitors in Low-Voltage Networks

Energies ◽  
2020 ◽  
Vol 13 (15) ◽  
pp. 3755 ◽  
Author(s):  
Luis Gerardo González ◽  
Rommel Chacon ◽  
Bernardo Delgado ◽  
Dario Benavides ◽  
Juan Espinoza

The power generated by photovoltaic solar systems is exposed to high variability of irradiance mainly due to weather conditions, which cause instability in the electrical networks connected to these systems. This study shows the typical behavior of solar irradiance in an Andean city, which presents considerable variations that can reach up to 63% of the nominal power of the photovoltaic system, at time intervals in the order of seconds. The study covers the application of 3 techniques to reduce power fluctuations at the point of common coupling (PCC), with the incorporation of energy storage systems, under the same irradiance conditions. Supercapacitors were used as the storage system, which were selected for their high efficiency and useful life. A state of charge control is also applied by means of a hysteresis band. The three algorithms studied show similar behaviors; however, the ramp control technique has the best performance. The storage system was dimensioned based on the photovoltaic system’s nominal power and the desired rate of change in the PCC, whose capacity can be estimated from Pnom/12 [kWh] and a maximum power that can reach up to 0.63 Pnom. The study determines that based on the storage capacity and the irradiance characteristics under study, the storage system could use at least 5.76 daily charge/discharge cycles. In the study, it is possible to reduce the rate of change of the photovoltaic energy injected into the PCC about 6.66 times with the use of the proposed energy storage system.

Author(s):  
Kaspars Kroics ◽  
Oleksandr Husev ◽  
Kostiantyn Tytelmaier ◽  
Janis Zakis ◽  
Oleksandr Veligorskyi

<p>Battery energy storage systems are becoming more and more popular solution in the household applications, especially, in combination with renewable energy sources. The bidirectional AC-DC power electronic converter have great impact to the overall efficiency, size, mass and reliability of the storage system. This paper reviews the literature that deals with high efficiency converter technologies for connecting low voltage battery energy storage to an AC distribution grid. Due to low voltage of the battery isolated bidirectional AC-DC converter or a dedicated topology of the non isolated converter is required. Review on single stage, two stage power converters and integrated solutions are done in the paper.</p>


Author(s):  
D.V.N. Ananth ◽  
G.V. Nagesh Kumar

In this paper, enhanced field oriented control technique (EFOC) was adopted in Rotor Side Control (RSC) of DFIG converter for improved response during severe faults. The work is intended to damp pulsations in electromagnetic torque, improve voltage mitigation and limit surge currents and to enhance the operation of DFIG during voltage sags. The converter topology uses a battery energy storage system with capacitor storage system to further enhance operation of DFIG during faults. The battery and capacitor system in coordination provide additional real and reactive power support during faults and nearly constant voltage profile at stator and rotor terminals and limit overcurrents. For EFOC technique, rotor flux reference changes its value from synchronous speed to zero during fault for injecting current at the rotor slip frequency. In this process DC-Offset component of flux is controlled, decomposition during overvoltage faults. The offset decomposition of flux will be oscillatory in a conventional FOC, whereas in EFOC it will damp quickly. A comparison is made with proposed methodology with battery energy storage system and a conventional system. Later the system performance with under voltage of 50% the rated voltage with fault at PCC during 0.8 to 1.2 seconds is analysed using simulation studies.


Complexity ◽  
2020 ◽  
Vol 2020 ◽  
pp. 1-19
Author(s):  
Muhammad Arif ◽  
Mohsin Shahzad ◽  
Qianmu Li ◽  
Jawad Saleem ◽  
Muhammad Shamrooz Aslam ◽  
...  

The multiport DC-DC power converter is a prominent area of research in power electronics due to its highly dense design, reduced device count, and high energy efficiency. In this paper, a nonisolated single magnetic element-based high step-up three-port converter for an energy storage system is presented. The proposed converter has two input ports and one output port. The coupled inductor with switched capacitor is used to achieve high voltage gain. The key features of the proposed converter are high conversion gain, low voltage stress, zero voltage switching (ZVS), and zero current switching (ZCS). The detailed theoretical analysis and operation of the converter are elaborated. The energy efficiency of the proposed converter is calculated and compared with the other counterparts. Ansys Maxwell is used for the coupled inductor finite element modeling. To verify the applicability and functionality of proposed converter, a 100  W converter with two inputs ( 48  V and 96  V ) and one output 360  V at 100  kHz is tested in the laboratory.


2022 ◽  
pp. 145-172
Author(s):  
Mahesh Kumar

In this chapter, the author presents the operation and power management of the hydrogen storage-based smart DC microgrid (DCMG). In this microgrid, several renewable distributed generations (DGs) such as wind turbine, solar photovoltaic system, solid oxide fuel cell (SOFC), and battery energy storage system are interconnected together and to the various DC and AC loads to form a ring-type low voltage distribution network. An additional storage as Hydrogen storage system has been connected to the dc microgrid for balancing the power at all times in the DCMG, under islanded mode operation, for all practical cases. An architecture of the hydrogen storage-based DC microgrid is suggested mainly for the remote rural area. For the regeneration of the electricity from the stored hydrogen, a SOFC DG system is also used in the proposed DCMG. A control technique is also developed for the operation of the hydrogen storage-based DCMG. The proposed DCMG system provides a reliable and high-quality power supply and will supply the power to all loads (both DC and AC) simultaneously.


Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 1121
Author(s):  
Rozmysław Mieński ◽  
Przemysław Urbanek ◽  
Irena Wasiak

The paper includes the analysis of the operation of low-voltage prosumer installation consisting of receivers and electricity sources and equipped with a 3-phase energy storage system. The aim of the storage application is the management of active power within the installation to decrease the total power exchanged with the supplying network and thus reduce energy costs borne by the prosumer. A solution for the effective implementation of the storage system is presented. Apart from the active power management performed according to the prosumer’s needs, the storage inverter provides the ancillary service of voltage regulation in the network according to the requirements of the network operator. A control strategy involving algorithms for voltage regulation without prejudice to the prosumer’s interest is described in the paper. Reactive power is used first as a control signal and if the required voltage effect cannot be reached, then the active power in the controlled phase is additionally changed and the Energy Storage System (ESS) loading is redistributed in phases in such a way that the total active power set by the prosumer program remains unchanged. The efficiency of the control strategy was tested by means of a simulation model in the PSCAD/EMTDC program. The results of the simulations are presented.


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