Shahid Iqbal

Vehicle-to-grid (V2G) technology lets a parked electric vehicle push power back to the network, so a fleet of cars can act as distributed storage. Many studies report large benefits from this, such as peak shaving and better use of renewable energy, but most describe their simulation only in words, name no test network, and compare a single charging behavior against a do-nothing case. It is then hard to separate what V2G delivers from what the control strategy delivers. This paper builds and compares dispatch strategies on one fully specified system: a price-following rule with no knowledge of the network, a stronger randomized time-of-use baseline, and a receding-horizon model predictive control (MPC) strategy that re-plans every hour with the distribution network’s per-line thermal limits and voltage bounds embedded directly in the optimization, not merely checked afterward. All run on the IEEE 33-bus feeder at low (10%), medium (30%), and high (50%) EV shares, with a full AC power flow solved every hour. The central result is a critical-penetration effect. At a 50% share, the naive price rule makes the system peak 23.7% worse than having no V2G at all, because the whole fleet reacts to one price signal at once, while the MPC cuts the peak by 18 to 28% in every case. Embedding the network limits removes the worst-line-loading side-effect a system-peak-only objective creates, bringing high-share worst-line loading down from 86.3% to 81.8% while preserving the full peak reduction. A workplace daytime-charging scenario shows renewable use becoming a real, separating metric (up to 2.8 MWh/day of EV demand met directly by rooftop solar, against zero for overnight charging), a quadratic wear cost smooths the profit-cycling frontier that a linear cost makes step-shaped, the controller is robust to forecast error up to 20%, and its solve time is set by network size rather than fleet size. Results are given as they came out of the model.

A bidirectional DC–DC converter is the part that lets an electric vehicle both draw a fast charge and push power back during vehicle-to-grid (V2G) operation, so its control decides how well the DC link holds up when the load jumps or the power reverses. This paper sets out a full switching-level model of a synchronous half-bridge converter that sits between a 400 V battery pack and a 750 V DC link at 50 kW, and it controls that converter with a two-loop sliding-mode scheme: an inner sliding-mode current loop with a boundary layer to limit chatter and an outer loop that holds the link voltage. The controller is written out term by term and compared against a conventional PI cascade on the same plant. Under a 40 to 100 percent load step, the sliding-mode controller settles the link in 0.71 ms with a 2.42 percent dip, against 1.75 ms and 4.20 percent for the PI cascade, and its response barely changes when the inductor is 40 percent larger and its resistance is 50 percent higher than the controller assumes, which is the invariance property sliding-mode control is meant to give. Power reverses from full discharge to full charge in 0.255 ms, about four and a half times faster than the same PI cascade taken through the reversal. A converter loss model, with conduction evaluated per switch from the RMS current, puts peak efficiency at 98.69 percent near 23 kW and 98.39 percent at the rated 50 kW. The converter is then driven by a real-world charging-demand profile taken from 41,213 charging sessions recorded at the Newcastle Helix site, and it holds the DC link within 9.12 V across the day. Every figure comes from the accompanying code and can be regenerated.

Technological advancements in solar power systems necessitate highly reliable power inverters with high efficiency and small size. An LLC resonant converter-based pseudo-Direct Current (DC) link inverters offer these qualities to some extent. The resonant circuits of conventional pseudo-DC link inverters cannot attain a zero gain and cannot handle variable frequency control which in turn requires very large filters to produce pure sinusoidal output voltages for the grid. The usage of these filters consequences in the enhanced price and size of inverters; moreover, the reliability of inverters is also reduced. We propose a novel topology for a pseudo-DC link inverter based on an LLCLC resonant converter. The proposed inverter does not require large filters, because it generates rectified sinusoidal output voltages. An additional parallel LC component is added in series to the resonant circuit, which makes it able to attain a zero gain through an infinite circuit impedance. The 400 W pseudo-DC link inverter with a 40 V input and a 400 V output is designed and simulated on OrCAD PSpice software. The results showed that there is a significant improvement in achieving a zero gain. The possible lowest gain achieved is approximately 0.125. The proposed technique claimed to be more efficient than those formerly used, subsequently contributing to satisfying outcomes.

This paper proposes a single-stage active power factor correction circuit for street LED light with battery back-up. The buck–boost converter and flyback converter are combined to achieve optimal performance. The first part of the integrated LED driver, the buck–boost converter is used to adjust the power while operating in the discontinuous conduction operation. The second part of the driver, the flyback converter provides regulated voltage to the LEDs. The battery backup circuit charges the battery when ac input power is available and provides power to LED lamp when input power supply is not available. The proposed LED driver was designed for 100 W output power and tested by PSpice simulation. The simulation results obtained are given in the paper to demonstrates the functionality of the proposed LED driver system. The result show good operation and performance of proposed LED driver.

This paper proposes a solar-powered resonant inverter fed a high-voltage DC power supply. In this converter, switching loss is controlled through zero-voltage switching and zero-current switching. This converter comprises a solar panel, boost converter, full-bridge LLC resonant tank, power transformer, and rectifier circuit. All power switches are operated with an interleaved switching cycle to ensure equal power flow from the tank. This proposed converter is designed to produce a regulated 19.5 KV at output, with an input voltage range of 300–350 V. The proposed converter was simulated in PSpice to verify the results.

This paper introduces and uses a single-phase, high-power LED driver with a battery backup. The buck–boost converter and reverse converter are both combined to achieve optimal performance. In the first part of the integrated circuit, the buck–boost converter is simply used to adjust the power when operating in the non-continuous operating mode. The reverse converter provides free voltage to the LEDs when released as a remote DC–DC converter. The battery backup cycle directly charges the battery at the same power as the LED driver required and provides charging power when there is no electricity. This paper demonstrates the functionality of the entire system and proves that it is an effective solution for new lighting applications.

Technological advancements in solar power systems necessitate highly reliable power inverters with a high efficiency and a small size. An LLC resonant converter-based pseudo Direct Current (DC) link inverters offer these qualities to some extent. The resonant circuits of conventional pseudo DC link inverters lack the ability to attain a zero gain and cannot handle variable frequency control which in turn requires very large filters to produce pure sinusoidal output voltages for grid. The usage of these filters consequences in the enhanced price and size of inverters; moreover, the reliability of inverters is also reduced. We propose a novel topology for a pseudo DC link inverter based on an LLCLC resonant converter. The proposed inverter does not require large filters, because it generates rectified sinusoidal output voltages. An additional parallel LC component is added in series to the resonant circuit, which makes it able to attain a zero gain through an infinite circuit impedance. The 400 W pseudo DC link inverter with a 40 V input and a 400 V output is designed and simulated on OrCAD PSpice software. The results showed that there is a significant improvement in achieving a zero gain. The possible lowest gain achieved is approximately 0.125. The proposed technique attested to be more efficient than those formerly used, subsequently contributing satisfying outcomes.

A voltage multiplier rectenna is a combination of a voltage multiplier rectifier and an antenna used for the conversion of AC to DC. It is an essential part of the system of RF energy harvesting. Conventional rectennas are characterized by low conversion efficiency. This study presents an analytical novel mode designed for RF energy harvesting systems to study the voltage and current output of rectifier stages for efficiency optimization. The design contains a voltage multiplier rectification circuit with seven stages. The Schottky diode HSMS 285-C was selected for the circuit modeling voltage multiplier circuit. Advanced Design System (ADS) simulation was used to validate the equations of the theoretical model solved with MATLAB code. The fabricated system was tested for an input power range of 10 μW to 100 mW; the maximum output power is 0.2577 mW with maximum efficiency of 29.85%.

Photovoltaic (PV) power is one of the promising solutions to address the fast-growing electricity demand. Electricity generated from the array of solar panels is not fixed due to the continuous change in environmental conditions. Therefore, an efficient power management system is required to facilitate the consumer with an uninterruptable power supply (UPS). When the energy demand is lower than the energy generated by the PV power system, the excessive energy must be stored in batteries and, when the energy demand is higher than the energy generated by the PV system, then the stored energy in the battery must be released in order to fulfil the load demand. Therefore, a bidirectional DC–DC converter is required to store and release energy. Conventional bidirectional converters offer low gain, low power density, low efficiency, high switching stress, and high magnitude of current and voltage ripples. In this paper, a bi-directional DC–DC converter that has low stress and low ripples is proposed for the operation of Stand-alone PV power systems. The proposed converter is implemented in ORCAD/PSPICE (Oregon Computer Aided Design/Personal Computer Simulation Program with Integrated Circuit) and both the charging and discharging modes have been analyzed explicitly. The results were compared with conventional converters and were found to be satisfactory. A significant improvement in the magnitude of output voltage and current ripples has been noticed. Besides, considerable improvement in switching stress (45% reduction as compared with conventional converters) and a 16.6% reduction in the magnitude of ripples was realized.

This paper proposes an interleaved LLC resonant converter with cascaded voltage doubler circuits for deeply depleted PEV battery charging. The use of voltage double circuits extends the operating range of converter by mitigating the effects of transformer’s parasitic capacitors. The converter has two modes of operation: simultaneous and independent. In former mode both interleaving converters operate together at same frequency and in later mode only one converter operates. In former mode, it yields twofold higher gain compared to later one. Thus, operation with combined mode changing and frequency control results in wider output voltage range. For confirmation, a laboratory prototype rated at input dc voltage of 400V and output power of 1.5kW is designed, and implemented. The results obtained from the prototype show that converter achieves a wide output voltage range of 100V–420V when operated in simultaneous mode with simple frequency control and an output voltage range of 50 –100V in the independent mode. With combined frequency and mode changing control it achieves an output range of 50V–420V. The peak efficiency of converter was measured to be 95.65% at a peak power of 1.5 kW. Thus, the proposed converter is suitable for the dc-dc stage of on-board PEV battery charger.