Powertrain control of a solar photovoltaic-battery powered hybrid electric vehicle

This paper proposes a powertrain controller for a solar photovoltaic battery powered hybrid electric vehicle (HEV). The main objective of the proposed controller is to ensure better battery management, load regulation, and maximum power extraction whenever possible from the photovoltaic panels. The powertrain controller consists of two levels of controllers named lower level controllers and a high-level control algorithm. The lower level controllers are designed to perform individual tasks such as maximum power point tracking, battery charging, and load regulation. The perturb and observe based maximum power point tracking algorithm is used for extracting maximum power from solar photovoltaic panels while the battery charging controller is designed using a PI controller. A high-level control algorithm is then designed to switch between the lower level controllers based on different operating conditions such as high state of charge, low state of charge, maximum battery current, and heavy load by respecting the constraints formulated. The developed algorithm is evaluated using theoretical simulation and experimental studies. The simulation and experimental results are presented to validate the proposed technique.     

Development of a thermoelectric battery-charger with microcontroller-based maximum power point tracking technique

This article describes a battery charger, which is powered by thermoelectric (TE) power modules. This system uses TE devices that directly convert heat energy to electricity to charge a battery. The characteristics of the TE module were tested at different temperatures. A SEPIC dc–dc converter was applied and controlled by a microcontroller with the maximum power point tracking (MPPT) feature. The proposed system has a maximum charging power of 7.99 W: that is better than direct charging by approximately 15%. The objectives are to study the principle of TE power generation and to design and develop a TE battery charger that uses waste heat or another heat source as the direct input power.     

A simple and low-cost charger for lithium-ion batteries

A simple low-cost battery charger based on a saturated controller is proposed for charging of lithium-ion (Li-ion) batteries. When the reference voltage of the closed-loop process is set to 4.2 V, the charging process resembles a constant-current and constant-voltage (CC-CV) charging strategy. The charging process can easily be shortened by raising the limit on the saturated controller. Experimental results are included to demonstrate the effectiveness of the charger. It is anticipated that the charger can be a low-cost high-performance replacement of existing Li-ion battery chargers.     

太阳能LED照明路灯充电器的研制

开发了一太阳能LED照明路灯系统,所提出的充电方法既能实现太阳电池的最大功率点跟踪(MPPT)又能满足蓄电池电压限制条件和浮充特性。结合开发实例对充电电路拓扑结构的选择、电路的启动、开关管的占空比、电路驱动和抗干扰问题进行了分析。所开发的系统已经稳定运行半年,测试表明:充电器能够依据蓄电池的不同状态准确切换到MPPT充电、恒压充电和浮充方式。充电器启动电流约为0.06A,最大工作电流可达到10A。     

System dynamic model and charging control of lead-acid battery for stand-alone solar PV system

The lead-acid battery which is widely used in stand-alone solar system is easily damaged by a poor charging control which causes overcharging. The battery charging control is thus usually designed to stop charging after the overcharge point. This will reduce the storage energy capacity and reduce the service time in electricity supply. The design of charging control system however requires a good understanding of the system dynamic behaviour of the battery first. In the present study, a first-order system dynamics model of lead-acid battery at different operating points near the overcharge voltage was derived experimentally, from which a charging control system based on PI algorithm was developed using PWM charging technique.The feedback control system for battery charging after the overcharge point (14 V) was designed to compromise between the set-point response and the disturbance rejection. The experimental results show that the control system can suppress the battery voltage overshoot within 0.1 V when the solar irradiation is suddenly changed from 337 to 843 W/m². A long-term outdoor test for a solar LED lighting system shows that the battery voltage never exceeded 14.1 V for the set point 14 V and the control system can prevent the battery from overcharging. The test result also indicates that the control system is able to increase the charged energy by 78%, as compared to the case that the charging stops after the overcharge point (14 V).     

Solar photovoltaic charging of lithium-ion batteries

Solar photovoltaic (PV) charging of batteries was tested by using high efficiency crystalline and amorphous silicon PV modules to recharge lithium-ion battery modules. This testing was performed as a proof of concept for solar PV charging of batteries for electrically powered vehicles. The iron phosphate type lithium-ion batteries were safely charged to their maximum capacity and the thermal hazards associated with overcharging were avoided by the self-regulating design of the solar charging system. The solar energy to battery charge conversion efficiency reached 14.5%, including a PV system efficiency of nearly 15%, and a battery charging efficiency of approximately 100%. This high system efficiency was achieved by directly charging the battery from the PV system with no intervening electronics, and matching the PV maximum power point voltage to the battery charging voltage at the desired maximum state of charge for the battery. It is envisioned that individual homeowners could charge electric and extended-range electric vehicles from residential, roof-mounted solar arrays, and thus power their daily commuting with clean, renewable solar energy.     

Development of a renewable hydrogen economy: Optimization of existing technologies

There is an increasing need for new and greater sources of energy for future global transportation applications. One recognized possibility for a renewable, clean source of transportation fuels is solar radiation collected and converted into useable forms of electrical and/or chemical (hydrogen) energy. This paper describes methods for utilizing and combining existing technologies into systems that optimize solar energy collection and conversion into useful transportation fuels. Photovoltaic (PV)-electrolysis (solar hydrogen) and PV-battery charging systems described in this paper overcome inefficiencies inherent in past concepts, where DC power from the PV system was first converted to AC current and then used to power electrical devices at the point of generation, or fed back to the grid to reduce electricity costs. These past, non-optimized concepts included efficiency losses in power conversion and unnecessary costs. These drawbacks can be avoided by capitalizing on the unique feature of solar photovoltaic devices that match their maximum power point to the operating point of an electrolyzer or a battery charger without intervening power transformers. This concept is illustrated for two systems designed, built, and tested by General Motors for fueling a fuel cell electric vehicle and charging an automotive propulsion battery. Based on this research, we propose a scenario in which individual home-owners, businesses, or sites at remote locations with no grid electricity, can capture solar energy, store it as hydrogen generated via water electrolysis, or as electrical energy used to charge storage batteries. Such a decentralized energy system provides a home refueling option for drivers who only travel limited distances each day.     

A Novel High-Efficiency Battery Charger With a Buck Zero-Voltage-Switching Resonant Converter

The high-frequency resonant converter has numerous well-known advantages over the traditional hard-switching converters. The most important advantage is that it offers a lower switching loss and a higher power density. Additionally, the soft-switching current waveform characterizes a lower electromagnetic interference (EMI). This study presents the circuit configuration with the least components to realize a highly efficient solar energy battery charger with a zero-voltage-switching resonant converter. The optimal values of the resonant components are determined by applying the characteristic curve and the electric functions derived from the circuit configuration. The experiment demonstrates the switching on and off of the main switches in a solar energy battery charger with a zero-voltage-switching resonant converter, wherein the switches are all operated using zero-voltage switching. The circuit efficiency in the overall charging process exceeds 80%.     

基于89C52的智能型快速充电器设计

文中从减少充电时间、提高充电效率的角度出发,在阶段充电方法的基础上设计一种正负脉冲型充电器。系统采用STC89C52单片机进行控制,在普通充电器的基础上增加了涓流充电和防极性反接等功能,大大延长蓄电池的使用寿命。     

太阳电池最大功率点追踪的控制策略

在研究太阳电池电路模型的基础上,提出了一种数模混合的最大功率点追踪策略,可以最大程度的利用太阳能,同时实现了蓄电池的过充保护,最后用实验验证了方案的高效性和实用性。     

Eco-green portable wireless power charger design with low-voltage,high-current fuel cell power source features

Since portable wireless power charger devices have grown rapidly in the market, this device has potential to become standard power charger for portable electronic devices. It offers enhanced consumer convenience and experience. This article presents an innovative portable wireless power charger that is more environmental-friendly because it uses a hydrogen gas fuel cell as the power source. Compared with fossil energy, the fuel cell is clean and renewable, which does not contribute a negative impact on the environment. A wireless power transmission (WPT) system was developed based on the electromagnetic induction technique in order to propagate electromagnetic energy from the transmitter to the receiver with operating frequency at 110 kHz. A four-cell proton exchange membrane fuel cell (PEMFC) planar module with open type at cathode side was applied to provide 4.11 W with its low-voltage and high-current features. A single-cell PEMFC produces output voltage ranging from 0.6 to 0.7 V and configures in serial to form a four-cell PEMFC planar module. Two DC-DC boost converter module in a parallel configuration was used to convert to a suitable voltage and current to the WPT module. The experimental validation shows that the developed system provides power around 1.6 W to the device battery under recharging with power efficiency delivery up to 70%. The charging experiment reveals the device battery capacity under recharging (cell phone) increases 1% in 3.3 minutes and it consumes the hydrogen at around 1.2 L.     

Battery chargers for electric vehicles

This article presents a comparative study of the performance of two types of battery chargers being developed for electric vehicles. The first charger is a microprocessor-based ferroresonant battery charger, referred to as the ferroresonant charger. The power delivery section of this charger is a ferroresonant transformer, which exploits the saturation of magnetic materials through its capacitor winding to produce a well-regulated output that resembles a square wave. The control section periodically places a resistive load across the battery under charge that allows this change in resistance to be detected. A microprocessor controls the timing and executes the gating of the needed switches in the circuit and then gathers and analyzes data from the battery charge monitor circuit. The monitor circuit measures the voltage drop across the battery, which is proportional to the battery internal resistance when the load is introduced. The second charger is a multiphase AC-to-DC converter that employs two three-phase transformers to create twelve phases and is called the twelve-phase charger. One transformer primary is in the delta configuration, and the other transformer primary is in the wye configuration. The center-tapped secondaries create the twelve phases. Thyristors are used to control the output voltage of the charger through digital control of the firing angle. A microprocessor controls the charging profile of the battery. A motor-generator set is used to simulate the load to the charger for test conditions     

PV-battery energy storage system operating of asynchronous motor driven by using fuzzy sliding mode control

This article tends on the designing of renewable-storage electrical system for asynchronous machine application. The machine requires a photovoltaic energy as a primary source of renewable energy. Such as the major drawback of solar sources are neither continuous nor regular in the time. To overcome this problem, a battery energy storage system will be added to make sure the continuity of the operation machine. Generally, electrical machine is driven by using sliding mode control where the major problem in this control technique design is chattering phenomenon which can be defeated using a sliding surface based on fuzzy logic. The proposed technique is performed with the proposed control system. A simulation test of the system for varied load motor conditions proved that the system is preferment. When, the generated power from PV is superior that the demands, the rest is stored in the battery. In the opposite condition, PV and battery required load. Moreover, the system which consists of machine and its control is enabling to produce electrical energy when it is functioning in the other sense of rotation. Four quadrant machine operations guarantee many possibilities of charging and discharging of the battery that assure the continuity of operating system.     

Improving a battery charger architecture for electric vehicles with photovoltaic system

In this study, a two-stage battery charger architecture with high-efficiency, multi-input, and output half-bridge LLC (HBLLC) resonance converter that performs a wide load range is proposed. The first input of the HBLLC is provided by the photovoltaic (PV) panel assembly on the vehicle. A high efficiency and fast maximum power point tracking (MPPT) algorithm has been developed for the PV panel to operate at the maximum power point. The other input is supplied by a grid-connected AC-DC bridgeless power factor correction (PFC) converter, which is controlled with the average current mode (ACM) control method. The most important feature that distinguishes the designed topology from previous studies is that it charges the low-voltage battery through the PV panel. In previous studies, the low-voltage battery was being charged via the high-voltage battery. This allowed the high-voltage battery to transfer power to the low-voltage battery even when it was not charged. However, in the proposed architecture, the low-voltage battery is fed by a PV panel. This condition allows the electric vehicle to take more miles with a single charge process. Furthermore, the proposed architecture reduces energy costs in the long term by providing some of the energy demanded from the grid. In addition, the proposed integrated battery charging circuit is intended to reduce the cost of additional cables. The system is designed as 3.1 kW power and operated under no load to full load. As for the performance of the proposed architecture, the peak efficiency of the LLC resonant converter is 95.3%. In addition, peak efficiency of the AC-DC bridgeless PFC converter is 97.3%, while the power factor is higher than 0.99, input current total harmonic distortion (THD) is less than 5%, MPPT method accuracy is higher than 99%, and output voltage ripples (ΔV) is less than 1 V.     

Comparison of a synergetic battery pack drive system to a pulsewidth modulated AC induction motor drive for an electric vehicle

A new battery configuration technique and accompanying control circuitry, termed a synergetic battery pack (SBP), is designed to work with lithium batteries, and can be used as both an inverter for an electric vehicle AC induction motor drive and as a battery charger. In this paper, the performance of a synergetic battery pack during motor drive operation is compared via computer simulation with a conventional motor drive which uses sinusoidal pulse width modulation (SPWM) to determine its effectiveness as a motor drive. The study showed that the drive efficiency was compatible with the conventional system, and offered a significant advantage in the lower frequency operating ranges. The voltage total harmonic distortion (THD) of the SBP was significantly lower than the PWM drive output, but the current THD was slightly higher due to the shape of the harmonic spectrum. In conclusion, the SBP is an effective alternative to a conventional drive, but the real advantage lies in its battery management capabilities and charger operation     

Lead-acid batteries for remote photovoltaic applications

The various load profile characteristics most commonly encountered in photovoltaic installations are analyzed in conjunction with solar array and battery performance data and used to generate battery specifications with particular respect to operating characteristics and cycle life requirements.The design of lead-acid batteries for photovoltaic applications is discussed and illustrated with both operating, maintenance, and cycle life data. Other performance characteristics of lead-acid photovoltaic batteries are described including the effects of operating temperature and the correct choice of charging method for various operational requirements.     

Optimal charging strategy design for lithium‐ion batteries considering minimization of temperature rise and energy loss

Battery charging techniques are critical to enhance battery operation performance. Charging temperature rise, energy loss, and charging time are three key indicators to evaluate charging performance. It is imperative to decrease temperature rise and energy loss without extending the charging time during the charging process. To this end, an equivalent circuit electrical model, a power loss model, and a thermal model are built in this study for lithium‐ion batteries. Then, an integrated objective function is formulated to minimize energy loss and temperature increment during battery charging. To further validate the generality and feasibility of the proposed charging strategy, experiments are conducted with respect to different current, operating temperatures, battery types, and aging status. Comparison results demonstrate that the devised charging strategy is capable of achieving the intended effect under any operating temperature and with different aging status.     

Optimal operation of microgrid using hybrid differential evolution and harmony search algorithm

This paper proposes the generation scheduling approach for a microgrid comprised of conventional generators, wind energy generators, solar photovoltaic (PV) systems, battery storage, and electric vehicles. The electrical vehicles (EVs) play two different roles: as load demands during charging, and as storage units to supply energy to remaining load demands in the MG when they are plugged into the microgrid (MG). Wind and solar PV powers are intermittent in nature; hence by including the battery storage and EVs, the MG becomes more stable. Here, the total cost objective is minimized considering the cost of conventional generators, wind generators, solar PV systems and EVs. The proposed optimal scheduling problem is solved using the hybrid differential evolution and harmony search (hybrid DE-HS) algorithm including the wind energy generators and solar PV system along with the battery storage and EVs. Moreover, it requires the least investment.