Storage Port Research Articles

A segmented‐region optimum EPS modulation scheme based on unified parameter algorithm in DAB‐based EV charger circuit

AbstractDue to galvanic isolation, bidirectional power transmission and extensive voltage adjustment, dual active bridge (DAB) exerts significant interface between renewable sources and electric vehicle (EV) storage port. However, for DAB operations, under light load or high voltage gain conditions, minimization of root‐mean‐square (RMS) current (MRMS) causes a restricted soft‐switching range. With variations of output power and operation modes, maintenance for all switches ZVS operation is difficult to maintain. Therefore, here, a segmented‐region optimum modulation (SROM) scheme based on extended‐phase‐shift (EPS) control is proposed to solve the aforementioned problems and solve complicated coupled relationship among different optimization methods. Firstly, based on voltage gain and transmission power, all EPS modes are divided clearly. Then, for switching loss reduction, fully‐power‐range ZVS (FZVS) is realized through transitions among EPS modes. Thirdly, either all semiconductors ZVS or not, most suitable optimization method is selected for different EPS regions by SROM. Further, to establish accurate boundaries among these optimization methods, relationship between inner phase‐shift ratio D1 and outer phase‐shift ratio D2 are quantified by unified parameter algorithm with unified parameter m. Therefore, for any EPS modes, efficiency is promoted comprehensively. A DAB‐based prototype is established and experimental results verify correctness and effectiveness of proposed method.

Design and analysis of multiple input single output converter for hybrid renewable energy system with energy storage capability

This paper proposes the design and analysis of a multiple-input-single-output (MISO) DC-DC converter suitable for a hybrid renewable energy system with energy storage capability. The converter design and control strategy validated in this research can be used to regulate the output dc voltage obtained from multiple-source renewable energy systems. The design is realized using a non-isolated double boost converter as it can handle bidirectional power flow at the storage port and has other advantages like compact structure, reduced number of components, and double boosting capability. The converter can also work without transformers, enabling the input renewable energy sources to operate individually. An inverted decoupler control strategy is adopted in the design of this novel converter. Mathematical models were developed to obtain the decoupler matrix, and the proposed control strategy is utilized to analyze the output. Simulations were performed on MISO converters with load and reference variations and is validated with the prototype. The current ripple percentage at the dual source side is found to be reduced by 2.6%. Also, the rise time, settling time, and percent overshoot of the output voltage were reduced by 0.03 s, 45 ms, and 3.6%, respectively. The performance of the proposed MISO converter is validated on a 50 W hardware prototype. The results validate the MISO converter's superior dynamic performance, output voltage regulation and reduced dual source ripple current, all of which are in agreement to the results of the simulation. A comprehensive comparison with the traditional controller is also conducted to further illustrate the advantages of the proposed inverted decoupler. The inverted decoupler validated in this work can be effectively used in hybrid renewable energy systems with energy storage capability, as it is found to be immune to the disturbances from the source end.

Design of a Power Converter for Solar Energy Storage System

This paper presents a single-stage three-port isolated power converter that enables energy conversion among a renewable energy port, a battery energy storage port, and a DC grid port. The proposed converter integrates an interleaved synchronous rectifier boost circuit and a bidirectional full-bridge circuit into a single-stage architecture, which features four power conversion modes, allowing energy adjustment for both the renewable energy and the battery storage energy ports when power is supplied by the renewable energy port. It also features bidirectional functionality that allows the battery storage energy port to provide energy storage through the DC grid port, thereby providing uninterrupted power supply functionality. The converter uses four power switches and two inductors to boost and convert energy from the renewable energy port to the battery storage energy port or to the DC grid port through the bidirectional full-bridge circuit. The converter is also capable of 1 kW power energy conversion by utilizing an adjustable duty cycle with a fixed frequency of 100 kHz and phase-shift control through a built-in pulse width modulation control module of a TMS320F28 series digital signal processor. According to the experimental results, the converter developed in this study can achieve a conversion efficiency of up to 94%.

Soft-switching buck/boost full-bridge three-port converter for DC/DC applications

In this paper, a new structure for a DC-DC full-bridge buck/boost LLC three-port converter (TPC) is proposed. The configuration of the converter is designed using the integration of an asymmetric fixed frequency full-bridge LLC network and the buck/boost circuit. The most important advantages of this structure can be summarized in features like the significant reduction of components, high efficiency, soft switching (ZVS and ZCS) and wide gain. In addition, using fixed frequency makes the design of different parts of the converter easier and more efficient. The proposed TPC integrates an input (source) port, a storage port, and an output port that is appropriate for Photovoltaic (PV)/battery hybrid power applications. The power management between ports is handled through two control variables, the duty cycle managed the power flow between the input and storage port, simultaneously the output voltage is adjusted by the phase shift (PS) Control variable. Finally, a laboratory prototype 48 V/8A output is built and experimental findings support the suggested TPC benefits and performance.

A New Five-Port Energy Router Structure and Common Bus Voltage Stabilization Control Strategy

Multi-port energy routers are a core device that integrates distributed energy sources and enables energy-to-energy interconnections. For the energy routing system, the construction of its topology, the establishment of internal model switching and the control of common bus voltage stability are the key elements of the research. In this paper, a five-port energy router structure is proposed, including a PV port, an energy storage port, a grid-connected port, a DC load port, and an AC load port. Among them, the energy storage port and the grid-connected port involve bidirectional energy flow, which are the core ports of control. For the system state, a model switching strategy is proposed based on the topology and the port energy flow direction. When the external conditions change, the system can be stabilized by means of a quick response from the energy storage port. When the energy storage is saturated, the state is switched, and the grid-connected port works to achieve system stability. The rapid stabilization of the bus voltage and the free flow of energy are achieved by combining the fast response of the model predictive control with the properties of multiple model switching. Finally, the feasibility of this energy router topology and control strategy is verified by building simulations in MATLAB.

Three-Port Forward Converters With Compact Structure and Extended Duty Cycle Range

A series of three-port forward converters with a compact structure and extended duty cycle range is presented for the standalone renewable energy system. Bidirectional power-flow port embedding and switch device sharing can be used to derive these converters from conventional two-switches forward converters. In comparison to the conventional two-switch forward converter, only one switch and one diode are added to build an energy storage port with bidirectional power flow characteristics, which has the benefits of compact structure and low cost. Meanwhile, the embedding of the energy storage port provides an additional demagnetization loop for the magnetic inductor, which extends the duty cycle range of the forward converter so that the proposed converter no longer requires a duty cycle of less than 0.5 as in the case of conventional forward converters. The proposed converters also offer the advantages of fewer components, easy control, and independent control of power flow between multiple ports when compared to similar solutions. Finally, an experimental setup with a photovoltaic battery as an application is developed, and the experimental results verify the effectiveness and flexibility of the proposed topology and control method.

Large-scale Hospital Material Supply Chain Practice under Closed-loop Management

In the context of public health emergencies, a Hospital used the existing SPD supply chain model as a basis, research and practice proceeded simultaneously and formed a set of "three-group three-port" emergency plan by itself. The program played a positive role and effectiveness in this emergency incident, assisting the hospital to obtain a valuable experience in closed-loop management of emergency supplies. This article elaborated on how the hospital can supply materials in case of emergency medical supplies shortage after emergencies by focusing on the three groups of closed-loop working group, inventory management group, and material procurement group, and the three ports of material storage port, logistics receiving and dispatching port, and closed-loop releasing port. In the case of emergency medical supplies being in short supply after emergencies, how can hospitals ensure adequate and balanced supply of supplies; barrier-free demand information; command and dispatch without chaos and reasonable deployment; materials receiving and dispatching are efficient and distributed in an orderly manner.

Multi‐application multi‐port DC–DC converter consisting six ports with four main operation modes

This paper proposes a multi-port DC–DC converter consisting of three input ports and two output ports extendable to three. The converter is designed based on quadratic boost converter, a technique for bidirectional port, an auxiliary source and two output ports with opposite polarities. Designed method of the configuration makes it suitable for multi-applications with flexible operations. Connection of the converter to a bipolar system is possible due to opposite polarities of output ports. In addition, output voltage can be doubled by series connection between the two out ports and it is introduced as the third output port of the converter. The other advantages of the converter are its appropriate voltage gain, performance in stand-alone mode with storage port and possibility of boosting voltage with similar voltage gains in different operation modes. To validate feasibility of the converter and investigate coordination of its performance with theory, a prototype is prepared for 120 W output power.

Three-Port Bidirectional Series-Resonant Converter With First-Harmonic-Synchronized PWM

An isolated three-port bidirectional series-resonant converter with first-harmonic-synchronized pulsewidth modulation (FHS-PWM) is proposed for energy storage applications. With FHS-PWM control, the voltage conversion ratio is only determined by the effective duty cycle and has nothing to do with the amplitude and direction of the transferred power. The operating mode can be transited between the forward and backward modes automatically and smoothly. The voltage of the output and energy storage ports can also be regulated individually with decoupling control. Furthermore, with the help of auxiliary inductors, zero-voltage switching (ZVS) of all the switches can also be achieved within the entire operating range. The detailed operation principles, characteristics, design considerations, and control strategy of the proposed converter are analyzed. An experimental prototype is built and tested to verify the effectiveness and feasibility of the proposed solution.

ОСОБЕННОСТИ РАЗВИТИЯ ИНФРАСТРУКТУРЫ ЗЕРНОВОГО ЭКСПОРТА И ОРГАНИЗАЦИОННО-ЭКОНОМИЧЕСКОГО МЕХАНИЗМА ЕЕ ФУНКЦИОНИРОВАНИЯ

The article examines the features of the development of Russian grain export and its infrastructure, as well as the organizational and economic mechanism of its functioning in the country. It is noted that in the near and more distant future, grain exports will retain their key role in the overall export of food products and agricultural raw materials. This will require the accelerated formation of facilities of a developed infrastructure and the creation of reliable logistics support for export grain supplies, significant organizational, financial and other support from the state, which implies the need for a transition to new forms of organizing grain commodity circulation on the principles of marketing and logistics, of introduction of transit schemes and intermodal transportation, formation of various logistics chains and a network of transport and logistics hubs based on intersectoral proportionality between the volumes of supply of commercial grain, of storage capacities, vehicles, port and transshipment capacities, as well as strengthening the coordination of actions of all the numerous participants in the movement of grain from domestic producers to its foreign consumers. In this regard, it is proposed to form the most effective national model for the development of grain exports. She should be based on the implementation of the state export policy, provide for the effective use of internal opportunities for increasing export grain resources, guarantee an optimal balance between the country’s internal needs for grain and real opportunities to increase its exports, and also have a rationally built system of market relations between all the numerous participants in the export segment of grain market. A well-organized and well-functioning system of economic relations between all links of the production and technological chains of grain movement will ensure an optimal balance between internal and external grain flows and promote a rhythmic supply of grain for export, without resorting to its sharp restrictions in some years.

Coastal Shuttle Tanker Scheduling Model Considering Inventory Cost and System Reliability

The near-sea off-shore oil extraction and transportation system use heterogeneous fleets to transfer crude oil from the floating production storage and offloading to the land-based oil storage port. Based on the characteristics of this system, the short sea inventory routing problem is investigated considering the shuttle tanker fleet and inventory management. In order to minimize the total operation cost and maximize the system reliability, a semi-continuous model for the shuttle tanker scheduling problem is established. The model optimizes the tanker scheduling plan and the design of the tanker fleet. To solve the complex model, this article proposes an improved non-dominated sorting genetic algorithm with differential evolution operator to solve the optimization of the multi-objective model. This research also uses public vessel operation data to test the modeling and optimizing efficiency. The Pareto Fronts associated with the total operation cost and the system reliability from the optimization outcome is analyzed to provide scheduling priority advice. The results indicate that proposed optimization algorithms are effective, and the operation could be optimized with the proposed model and algorithm.

A Three-Port LLC Resonant DC/DC Converter

This paper proposes a new three-port LLC resonant converter which integrates input port, storage port, and load port in one converter. A pulse-frequency modulation and phase-shift combined control method are adopted for the proposed topology. It has four different operation modes with different gains and different power directions between input port, storage port, and load port, which are attractive for renewable energy with energy storage system applications. The proposed topology operates under resonant frequency, which is easy to implement with digital control, and it can achieve soft switching for almost all the switches and diodes similar to conventional LLC resonant converter. The performance of the proposed converter is validated by the experimental results from a 500-W prototype with 1.25-A maximum output current.

Studi Kelayakan Ekonomis Rencana Pembangunan Pelabuhan Sungai Liong Desa Berancah Kabupaten Bengkalis

The fish shelter port (TPI) is a need that needs to be prepared by local village officials and the government for every coastal village in Bengkalis Regency. This research was conducted in the Berancah village of Bantan District. The analysis in this study describes the economic feasibility mathematically for the construction of a fish storage port (TPI) by calculating the cost ratio (B / C ratio) benefit analysis, payback period (PP), net present value (NPV), and internal rate of return ( IRR). The results obtained from the NPV value (3,661,267,645), BCR value (0.943), IRR value of 10.01%, and PP are in the period of 30 years. Taken as a whole by standardizing the calculations, it can be concluded that the planned construction of a fish shelter in Berancah village is considered not economically feasible, but economic analysis is not merely a benchmark for feasibility, reviewed for the future many benefits will be received by the community around the location of the development plan so that it can improve the welfare of the community in Berancah village.

Droop-Controlled Rectifiers That Continuously Take Part in Grid Regulation

In this paper, a generic framework for a rectifier to continuously take part in the regulation of grid voltage and frequency is proposed. It can automatically change the power consumed to support the grid, without affecting the normal operation of the load. Such a rectifier has a built-in storage port, in addition to the normal ac and dc ports. The flexibility required by the ac port to support the grid is provided by the storage port without affecting the dc port. The grid support of the ac port is achieved through the recently proposed universal droop controller (UDC). A dc-bus voltage controller cascaded to the UDC is proposed to regulate the dc-bus voltage of the storage port within a wide range so as to provide the flexibility needed, while the dc-port voltage is maintained constant. An illustrative example is presented with the recently proposed $\theta$ -converter, which consists of three ports with only four switches. Experimental results are provided to verify the capability of the rectifier to regulate the grid voltage and frequency without affecting the load.

Design and Application of Toxic and Harmful Gas Monitoring System in Fire Fighting.

In recent years, fire accidents in petrochemical plant areas and dangerous goods storage ports in China have shown a trend of frequent occurrence. Toxic and harmful gases are diffused in the scenes of these accidents, which causes great difficulties for fire fighting and rescue operations of fire fighting forces, and consequently, casualties of firefighters often occur. In order to ensure the safety of firefighters in such places, this paper designs a monitoring system of toxic and harmful gases specially used in fire fighting and rescue sites of fire forces, and establishes the transmission network, monitoring terminal and data processing software of the monitoring system of toxic and harmful gases, establishing the danger model of the monitoring area of toxic and harmful gas-monitoring terminal, and the danger model of fire fighters’ working area, fusing the field toxic and harmful gas data, terminal positioning data, and field environmental data, designing the data structure of the input data set and the network structure of the RNN cyclic neural network model, and realizing the dynamic early warning of toxic and harmful gases on site.

Decoupled TAB converter with energy storage system for HVDC power system of more electric aircraft

It is an important trend to develop the more electric aircraft (MEA) ±270 V high-voltage direct current (HVDC) power system because of its better reliability, power quality and power density. However, there also exists the low-voltage 28 V DC system in HVDC power system, for the aviation battery and some equipment still rely on it. In traditional MEA power systems, battery is only used as a backup power supply, hardly participating in the adjustment of the power system. On the other hand, the function of turbine engine is unidirectional. Hence, it's necessary to add an energy storage port. In this research, the authors put forward the problems of power coupling and strong non-linearity in traditional three-port triple active bridge (TAB) converters, and propose a decoupled TAB topology, which has the feature of decoupled power flow. The topology is compatible with ±270 V DC, 28 V DC and energy storage system with high-power density and efficiency. In addition, the authors unify the efficiency optimisation problem of dual active bridge topology mathematically and provide an optimal parameter design approach for inductance and turns ratio. Simulation results show the power flow control strategy is appropriate for the topology.

Analysis of Distribution Characteristics and Source of Dissolved Organic Matter from Zhoucun Reservoir in Summer Based on Fluorescence Spectroscopy and PARAFAC

The fluorescent components were examined using excitation emission matrix fluorescence spectroscopy-parallel factor analysis technique for samples collected in August, 2015 from Zhouncun Reservoir. Principal component analysis was used to study the main factors and their relative contributions to DOM. Three fluorescent components were identified by PARAFAC, including fulvic-like component(C1:260,350/420 nm), protein-like(C2:280/360 nm) and humic-like (C3:270,390/530 nm) which showed the same source. The even spatial distribution of each component, higher total fluorescence intensity in storage port, high fluorescence index, high biological index, low humification index and the freshness index which was close to one showed that the DOM had a strong autochthonous contribution. The results of PCA showed that the autochthonous contribution reached 70.86%, and those three components of Zhoucun Reservoir could be connected with aph(440) by nonlinear multiple regression which means we can use the three-dimensional fluorescence spectrum results of DOM to control the pollution sources and indicate the eutrophication degree of Zhoucun Reservoir.

Synthesis and Implementation of a Multi-Port DC/DC Converter for Hybrid Electric Vehicles

A non-isolated Multiple Input Converter (MIC) with an input port, two storage ports and a load port is proposed. The synthesis of the proposed four port converter with its switch realization is presented. A steady state analysis of each operating mode with a small-signal model is derived, and a stability analysis is done. A mode selection controller is proposed to automatically choose a specific operating mode based on the voltage levels of the different source and storage units. In addition, a voltage control loop is used to regulate the output voltage. A 200W prototype is built with a TMS320F28027 DSP controller to test the feasibility of the operating modes. Simulation and experimental results show the ability of the proposed converter to handle multiple inputs either individually or simultaneously.

Analysis of Three Port Full Bridge and Half Bridge DC-DC Converter Interfacing Renewable Energy System

This paper presents the comparative dynamic analysis of full bridge and half bridge three port dc-dc converter topology interfacing the renewable energy sources along with the energy storage devices. The three port converter comprises the active bridge circuit and the three winding transformer. It uses single power conversion stage with high frequency link to control power flow between the batteries, load and the renewable energy sources. The power flow between the ports is controlled by phase shifting the square wave outputs of the active bridges in combination with pulse width modulation (PWM) technique. The analysis reveals that the battery discharges when the source is not sufficient to supply the load and it was charged when the source alone is capable of supplying the load. Hence there is a bidirectional power flow in the storage port when there is a transition in the source.

Multiport Converter for Fast Charging of Electrical Vehicle Battery

The availability of new electrical vehicle batteries with high current rating and capacity permits the realization of rapid charging. However, when using conventional methods, the charging process requires an expensive high-current grid interface. Therefore, a multiport converter with a stationary storage port to reduce the current required from the grid is proposed. The goal of this paper is to explore the fundamentals of the converters used in each port. Experimental results are shown to validate the study.