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... gen- eral, a unidirectional DC-DC converter can be turned into a bidirectional converter by replacing the diodes with a controllable switch in its structure. Figure 4 shows the structure of elementary buck and boost converters and how they can be transformed into bidirectional converters by replacing the diodes in their struc- ture. It is noteworthy that the resulted converter has the same structure in both cases. ...
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... In recent days medium and large-scale industries utilizing more outdoor and indoor energy harvester circuits for balancing energy demand within industry units [9]. Generally solar and wind energy conversion performs an energetic role in outdoor energy harvesters but both depend upon geographical location and weather parameters, also solar energy conversion indirectly emits a particular percentage of Carbon di-oxide gases from the energy conversion process, therefore lot of energy researchers focusing to utilize MEMS based kinetic energy extraction for clean and sustainable electrical energy generation also the electrokinetic energy conversion process not emitting any kind of harm full gases to the environment. ...
... In this context, D 2 stands for the duty cycle in boost mode, and we can determine its value using Equation (36), as indicated in references [84,[86][87][88]. ...
Wind energy is an increasingly important renewable resource in today’s global energy landscape. However, it faces challenges due to the unpredictable nature of wind speeds, resulting in intermittent power generation. This intermittency can disrupt power grid stability when integrating doubly fed induction generators (DFIGs). To address this challenge, we propose integrating a Li-ion battery energy storage system (BESS) with the direct current (DC) link of grid-connected DFIGs to mitigate power fluctuations caused by variable wind speed conditions. Our approach entails meticulous battery modeling, sizing, and control methods, all tailored to match the required output power of DFIG wind turbines. To demonstrate how well our Li-ion battery solution works, we have developed a MATLAB/Simulink R2022a version model. This model enables us to compare situations with and without the Li-ion battery in various operating conditions, including steady-state and dynamic transient scenarios. We also designed a buck–boost bidirectional DC-DC converter controlled by a proportional integral controller for battery charging and discharging. The battery actively monitors the DC-link voltage of the DFIG wind turbine and dynamically adjusts its stored energy in response to the voltage level. Thus, DFIG wind turbines consistently generate 1.5 MW of active power, operating with a highly efficient power factor of 1.0, indicating there is no reactive power produced. Our simulation results confirm that Li-ion batteries effectively mitigate power fluctuations in grid-connected DFIG wind turbines. As a result, Li-ion batteries enhance grid power stability and quality by absorbing or releasing power to compensate for variations in wind energy production.
... DC-DC converters and charge controllers are two common energy harvesting methods. There are several steps in the conversion process (Suresh and Arulmozhiyal, 2016). As a result, the system's complexity, size, and cost grow. ...
As the use of renewable energy sources grows in grids, battery energy storage systems become increasingly important for grid stability and reliability. The bidirectional converter can provide battery devices charging and discharging of energy in both directions. This paper presents a bidirectional DC to DC converter for energy storage systems and a proportional and integral controller (PI) for charging and discharging applications. The simulation is carried out in MATLAB/Simulink environment.
... where ΔV o is the voltage ripple across DC-link capacitor. The design of the boost converter for WECS is also done in the similar manner [37]. ...
This article presents the grid connected hybrid solar-wind energy conversion system (HSWECS) using the cascaded diode clamped multilevel inverter (CDCMLI). The advantage of CDCMLI over the conventional cascaded H-bridge multilevel inverter (CHBMLI) is that the power transfer capacity of the CDCMLI is doubled. The solar and wind energy conversion systems are connected individually to the DC-links of CDCMLI through the DC–DC converter which is used to get maximum power from solar and wind systems. Due to the fluctuating power supply by renewable sources, the isolated DC-links of separate inverters suffer from varying DC-link voltages. A control scheme is proposed which is capable of balancing these DC-link voltages under various power generation scenarios, extracting the maximum possible power from renewable energy sources (RES), and injecting it into the grid at near unity power factor. The proposed control also monitors the power quality of the injected current into the grid. Furthermore, it allows the system to be connected to the grid without any transformer. In addition, mathematical modeling of the CDCMLI has been presented. The performance of the system is analyzed with Matlab/Simulink and confirmed by a prototype model with dSpace 1104.
... Variable DC voltage is obtained in the output of this rectifier. DC-DC boost converter is also named as step-up converter, whose output voltage is larger than input voltage [33]. Boost converter includes an inductor, a power electronic switch such as MOSFET or IGBT, a diode and a capacitor. ...
Modular multilevel converters (MMCs) can be a reliable solution since they have modular structure and high quality output
waveform for permanent magnet synchronous generator (PMSG) based wind energy conversion system (WECS). Capacitor voltage
balancing in nearest level modulation (NLM) is required to keep the capacitor voltage of each submodule of MMC constant.
In this paper, an efficient capacitor voltage balancing scheme under NLM is proposed for PMSG based WECS with MMC topology.
Through proposed control scheme, arm voltages are separately controlled and voltage ripple of around 1.5% is obtained.
This result provides high quality output waveform at the point of common coupling (PCC). Furthermore, DC-link voltage
control is achieved via hysteresis current control based proportional-integral controller. The ripple of DC-link
voltage is obtained quite well as nearly 0.25%. In addition, load voltage control is accomplished using dq reference
frame-based voltage control scheme for voltage and frequency stabilization at the PCC by regulating the voltage at
its reference value. Simulation studies show that all proposed control schemes give satisfactory results for MMC
based WECS under variable dynamic operation modes. Finally, experimental verification is performed using laboratory
prototype to show the applicability of the proposed capacitor voltage balancing scheme.
... Figures[10] and[11] display the battery output voltage and SOC respectively during buck mode. The battery needs 100 ms to charge from 12.2 Volt to 13 Volt. ...
This research intends to build and simulate a small renewable energy system consists of PV panel, lead-acid battery, and bidirectional DC-DC converter. Bidirectional Buck-Boost converter was used to regulating the voltage and current coming from the solar panels going to the battery and vice versa. It operates a Buck converter which charges the battery from the PV panel when State of charge (SOC) reaches less than 0.4. The battery needs 100 ms to charge from 12.2 V to 13 V with duty cycle 0.5 and 1 A. Also work as a Boost converter when SOC reaches 1 the battery was discharge for 100 ms and SOC decreases from 1 to 0.4.
A PSPICE PV panel model (consists of 20 solar cells, 12 V and 60 W maximum power at 25 °C with 1000 W/m ² solar irradiation) has been used as a source of energy to the power circuit. The output of PV panel relates to Boost converter, which is the key for changing the PV’s terminal voltage to track the maximum power, it was rising a PV panel voltage from 10 V to 22 V for all variation of surface temperature from 300 K to 350 K at frequency 10 kHz and ΔVo = 1.1 V.
... A one of the simplest converters is the buck-boost bidirectional DC-DC converter [8]. This type of converters is utilized in case of the DC link voltage is higher than the energy storage system voltage less, than 5÷7 times [10]. Therefore, a main advantage of this type of converter is a transformer absence and a relatively low cost. ...
... The critical value of battery side capacitor to reduce ripple of battery voltage is calculated with (26) where Imac represents dc machine current and ΔVmacmax is maximum ripple value of voltage of the dc machine [18]. The critical value of motor side capacitor to reduce ripple of voltage is calculated with (27) where ILmax represents inductor current fluctuate of bi-directional dc-dc converter [18]. ...
... The critical value of battery side capacitor to reduce ripple of battery voltage is calculated with (26) where Imac represents dc machine current and ΔVmacmax is maximum ripple value of voltage of the dc machine [18]. The critical value of motor side capacitor to reduce ripple of voltage is calculated with (27) where ILmax represents inductor current fluctuate of bi-directional dc-dc converter [18]. The parameters of bi directional dc dc converter are given in Table III. ...
... Interface mechanism makes inferences according to the rules of system by establishing a relationship between inputs. Defuzzification is used to convert linguistic variable received through the system into digital signals [18]. ...
... The main circuit topology of bi-directional DC-DC converter is shown in Figure 1. Figure 1. The main circuit topology of bi-directional DC-DC converter Bi-directional DC-DC converter has three operation modes [7]: Buck mode, Boost mode and alternate mode. The alternate mode is equivalent to the alternation between Buck mode and Boost mode in a short time, and therefore this paper concentrates on the first two operation modes. ...
... The state vector X dot is expressed in state variables such as A 2 and B 2 . The time interval of the primary switches is ON are expressed in the equation 13. ...
The proposed system also has boost converter, bidirectional DC-DC converter and inverter for grid and wind energy integration. The boost inverter/buck rectifier in this system is controlled by ANFIS controller is for better output, boost and bidirectional DC-DC converters are controlled by PID controller in closed loop. Overall operations are based on modes main controller speedgoat, which is control the system operation in different modes. Any variation happening in the input, storage and load parameters speedgoat changing the mode and operate the system is in effective way. This paper presents harnessing of maximum wind energy from natural resource whenever it's available. The power electronic converters role is important In between sources and load. The load may be linear and non-linear in nature, so converters performance decides the efficiency of the system. Proper controller can switch the converter in the desired time and improve the system performance and stability. Many controllers are suggests to control the converter to get better performance in at output side.
