Research on Control Strategy of the Stand-Alone PV/Battery System

2013 ◽  
Vol 860-863 ◽  
pp. 168-171
Author(s):  
Shu Zhao Wang ◽  
Hong Bin Wu
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Photovoltaic System ◽  
Power Fluctuation ◽  
Battery System ◽  
Voltage Frequency ◽  
Dc Bus ◽  
And Control ◽  
Hysteresis Control

With the battery charging or discharging, it can effectively stabilize power fluctuation of the photovoltaic generation (PV) or the load in a stand-alone power generation system. In this paper, based on the mathematical models of the PV and the battery, it connected the PV and the battery on the same DC bus and proposed energy management system with hysteresis control on the DC bus. In order to prevent the battery from switching back and forth among working state and stopping state, the outer voltage loop took the nonlinear function control strategy of the battery. With the inverter adopting voltage frequency (V/f) control strategy, it maintained the voltage and frequency on AC bus. With the PSCAD/EMTDC, it analyzed the ability of the battery stabilizing the power fluctuation of the PV or the load. And it proved the correctness and feasibility of the established models and control strategies. So those provided theoretical reference for the photovoltaic system that was employed efficiency in the remote areas.

A power management and control strategy with grid-ancillary services for a microgrid based on DC Bus

2014 ◽  
Vol 9 (4) ◽  
pp. 792 ◽  
Author(s):  
Anna Pinnarelli ◽  
Giuseppe Barone ◽  
Giovanni Brusco ◽  
Alessandro Burgio ◽  
Daniele Menniti ◽  
...  
Keyword(s):  
Power Management ◽  
Control Strategy ◽  
Ancillary Services ◽  
Dc Bus ◽  
And Control

A High Gain Novel Double-Boost Converter for DC Microgrid Applications

2020 ◽  
Vol 29 (15) ◽  
pp. 2050246 ◽  
Author(s):  
B. N. Ch. V. Chakravarthi ◽  
G. V. Siva Krishna Rao
Keyword(s):  
Control Strategies ◽  
High Gain ◽  
Photovoltaic System ◽  
Solar Photovoltaic ◽  
Dc Microgrid ◽  
Boost Converters ◽  
Power Point ◽  
Solar Photovoltaic System ◽  
Conversion Stage ◽  
And Control

In solar photovoltaic (PV)-based DC microgrid systems, the voltage output of the classical DC–DC converter produces very less voltage as a result of poor voltage gain. Therefore, cascaded DC–DC boost converters are mandatory for boosting the voltage to match the DC microgrid voltage. However, the number of devices utilized in the DC–DC conversion stage becomes higher and leads to more losses. Thereby, it affects the system efficiency and increases the complication of the system and cost. In order to overcome this drawback, a novel double-boost DC–DC converter is proposed to meet the voltage in DC microgrid. Also, this paper discusses the detailed operation of maximum power point (MPP) tracking techniques in the novel double-boost DC–DC converter topology. The fundamental [Formula: see text]–[Formula: see text] and [Formula: see text]–[Formula: see text] characteristics of solar photovoltaic system, operational details of MPP execution and control strategies for double-boost DC/DC converter are described elaborately. The proposed converter operation and power injection into the DC microgrid are verified through the real-time PSCAD simulation and the validation is done through the experiment with hardware module which is indistinguishable with the simulation platform.

scholarly journals New Pulse Width Modulation Technique to Reduce Losses for Three-Phase Photovoltaic Inverters

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Mohannad Jabbar Mnati ◽  
Dimitar V. Bozalakov ◽  
Alex Van den Bossche
Keyword(s):  
Control Strategy ◽  
Pulse Width Modulation ◽  
Photovoltaic System ◽  
Pv System ◽  
Total Cost ◽  
Switching Losses ◽  
Three Phase ◽  
Operational Lifetime ◽  
Term Energy ◽  
Dc Bus

Nowadays, most three-phase, “off the shelf” inverters use electrolytic capacitors at the DC bus to provide short term energy storage. However, this has a direct impact on inverter lifetime and the total cost of the photovoltaic system. This article proposes a novel control strategy called a 120° bus clamped PWM (120BCM). The 120BCM modulates the DC bus and uses a smaller DC bus capacitor value, which is typical for film capacitors. Hence, the inverter lifetime can be increased up to the operational lifetime of the photovoltaic panels. Thus, the total cost of ownership of the PV system will decrease significantly. Furthermore, the proposed 120BCM control strategy modulates only one phase current at a time by using only one leg to perform the modulation. As a result, switching losses are significantly reduced. The full system setup is designed and presented in this paper with some practical results.

Study and Simulation on the Energy Efficiency Management Control Strategy of Ship Based on Clean Propulsion System

2015 ◽  
Author(s):  
Kai Wang ◽  
Xinping Yan ◽  
Yupeng Yuan
Keyword(s):  
Energy Efficiency ◽  
Energy Consumption ◽  
Control Strategy ◽  
Control Strategies ◽  
Management Control ◽  
Propulsion System ◽  
Power Requirement ◽  
Doubly Fed ◽  
System Configurations ◽  
And Control

Nowadays, with the higher voice of ship energy saving and emission reduction, the research on energy efficiency management is particularly necessary. Energy efficiency management and control of ships is an effective way to improve the ship energy efficiency. In this paper, according to the new clean propulsion system configurations of 5000 tons of bulk carrier, the energy efficiency management control strategy of the clean propulsion system is designed based on the model of advanced brushless doubly-fed shaft generator, propulsion system using LNG/diesel dual fuel engine and energy consumption of the main engine for reducing energy consumption. The simulation model of the entire propulsion system and the designed control strategy were designed. The influence of the engine speed on the ship energy efficiency was analyzed, and the feasibility of the energy efficiency management control strategies was verified by simulation using Matlab/Simulink. The results show that the designed strategies can ensure the power requirement of the whole ship under different conditions and improve the ship energy efficiency and reduce CO2 emissions.

Study on a global control strategy for rotation speed with different work states in variable-speed constant-frequency wind turbines

2011 ◽  
Vol 225 (7) ◽  
pp. 968-976 ◽  
Author(s):  
G Zheng ◽  
H Xu ◽  
X Wang ◽  
J Zou
Keyword(s):  
Wind Turbine ◽  
Wind Turbines ◽  
Control Strategy ◽  
Control Strategies ◽  
Stable Operation ◽  
Constant Frequency ◽  
Global Control ◽  
Control Rules ◽  
The Individual ◽  
And Control

This paper studies the operation of wind turbines in terms of three phases: start-up phase, power-generation phase, and shutdown phase. Relationships between the operational phase and control rules for the speed of rotation are derived for each of these phases. Taking into account the characteristics of the control strategies in the different operational phases, a global control strategy is designed to ensure the stable operation of the wind turbine in all phases. The results of simulations are presented that indicate that the proposed algorithm can control the individual phases when considered in isolation and also when they are considered in combination. Thus, a global control strategy for a wind turbine that is based on a single algorithm is presented which could have significant implications on the control and use of wind turbines.

Control Strategy of the Hybrid Energy Storage System for Leveling Off Fluctuating Power Output of Stand-Alone Photovoltaic System

2013 ◽  
Vol 860-863 ◽  
pp. 608-612
Author(s):  
Hai Bo Wang ◽  
Xiu Yang ◽  
Jun Liu ◽  
Jie Chen
Keyword(s):  
Energy Management ◽  
Control Strategy ◽  
Storage System ◽  
Energy Storage System ◽  
Photovoltaic System ◽  
Super Capacitor ◽  
Hybrid Energy ◽  
Hybrid Energy Storage ◽  
Hybrid Energy Storage System ◽  
And Control

Hybrid energy storage system (HESS) including battery and super-capacitor can take advantages of both high energy density and high power density. In the stand-alone PV micro-grid, in which two buck/boost bidirectional converters are connected to the DC bus directly, a novel energy management scheme is proposed. After filtering the fluctuating power of the HESS, charge and discharge currents of the battery are controlled by hysteresis control method, the super-capacitor supplies the difference of the power. To leveling off the fluctuating power output of photovoltaic system and control the voltage of the DC bus, a new control strategy applied to the bidirectional converter of the super capacitor is put forward. The feed-forward loops of input voltage, load current and output voltage are introduced to improve the response speed and stability of the system. Results of the simulation show the effectiveness of the proposed energy management and control strategy.

scholarly journals Pressure Control of Insulation Space for Liquefied Natural Gas Carrier with Nonlinear Feedback Technique

2018 ◽  
Vol 6 (4) ◽  
pp. 133
Author(s):  
Jinghua Cao ◽  
Xianku Zhang ◽  
Xiang Zou
Keyword(s):  
Natural Gas ◽  
Control Strategy ◽  
Control Strategies ◽  
Nonlinear Function ◽  
Pressure Control ◽  
Feedback Signal ◽  
Control Input ◽  
Nonlinear Feedback ◽  
Pressure Control System ◽  
Liquid Natural Gas

This paper introduces a novel control strategy into the insulation space for liquid natural gas carriers. The control strategy proposed can improve the effects of control for differential pressure and reduce the energy consumption of nitrogen. The method combines a nonlinear feedback technique with a closed-loop gain shaping algorithm (CGSA). It is designed for the pressure control system which is vital for liquid natural gas carriers (LNGCs) in marine transportation. The control error is modulated using nonlinear function. The deviation signal is replaced with a nonlinear feedback signal. Comparison experiments are conducted under different conditions to prove the effectiveness of this strategy. This paper compares three control strategies: a control strategy with nonlinear feedback based on CGSA, a control strategy without nonlinear feedback based on CGSA, and a two-degree-of-freedom (DOF) control strategy. The simulation results show that this control strategy with nonlinear feedback performs better than the other two. The average reduction of control input is about 38.8%. The effect of pressure control is satisfactory.

Downshifting Control Strategy for Dual Clutch Transmission With Single Clutch Slippage

2016 ◽  
Author(s):  
Jikai Liu ◽  
Biao Ma ◽  
Heyan Li ◽  
Man Chen ◽  
Jianwen Chen
Keyword(s):  
Control Strategy ◽  
Control Strategies ◽  
Bench Test ◽  
Dual Clutch Transmission ◽  
Pressure Profiles ◽  
Simulation Results ◽  
And Control ◽  
Engagement And Disengagement ◽  
External Loads ◽  
Good Agreement

The cooperation mode between the engagement and disengagement clutches for vehicles equipped with Dual Clutch Transmission (DCT) is of vital importance to achieve a smooth gearshift, in particular for the downshift process as its unavoidable power interruption during the inertia phase. Hence, to elevate the performance of DCT downshifting process, an analytical model and experimental validation for the analysis, simulation and control strategy are presented. Optimized pressure profiles applied on two clutches are obtained based on the detailed analysis of downshifting process. Then, according to the analysis results, a novel control strategy that can achieve downshift task with only one clutch slippage is proposed. The system model is established on Matlab/Simulink platform and used to study the variation of output torque and speed in response to different charging pressure profiles and various external loads during downshifting process. Simulation results show that, compared with conventional control strategies, the proposed one can not only avoid the torque hole and power circulation, but shorten the shift time and reduce the friction work. Furthermore, to validate the effectiveness of the control strategy, the bench test equipped with DCT is conducted and the experiment results show a good agreement with the simulation results.

Modeling the System and Component Performance Interactions of a SOFC Based APU for Changes in Application Load: Transient Response and Control Strategy

2004 ◽  
Author(s):  
D. F. Rancruel ◽  
M. R. von Spakovsky
Keyword(s):  
Transient Response ◽  
Control Strategy ◽  
Control Strategies ◽  
Control Variable ◽  
System Level ◽  
System Component ◽  
System Response ◽  
Optimal Control Strategy ◽  
Synthesis Design ◽  
And Control

Solid-Oxide-Fuel-Cell (SOFC) stacks respond in seconds to changes in load while the balance of plant subsystem (BOPS) responds in times several orders of magnitude higher. This dichotomy diminishes the reliability and performance of SOFC electrodes with changes in load. In the same manner current and voltage ripples which result from particular power electronic subsystem (PES) topologies and operation produce a negative effect on the SOFC stack subsystem (SS) performance. The difference in transient response among the sub-systems must be approached in a way which makes operation of the entire system not only feasible but ensures that efficiency and power density, fuel utilization, fuel conversion, and system response are optimal at all load conditions. Thus, a need exists for the development of transient component- and system-level models of SOFC based auxiliary power units (APUs), i.e. coupled BOPS, SS, and PES, and the development of methodologies for optimizing subsystem responses and for investigating system-interaction issues. In fact the transient process occurring in a SOFC based APU should be systematically treated during the entire creative process of synthesis, design, and operational control, leading in its most general sense to a dynamic optimization problem. This entails finding an optimal system/component synthesis/design, taking into account on- and off-design operation, which in turn entails finding an optimal control strategy and control profile for each sub-system/component and control variable. Such an optimization minimizes an appropriate objective function while satisfying all system constraints. A preliminary set of chemical, thermal, electrochemical, electrical, and mechanical models based on first principles and validated with experimental data have been developed and implemented using a number of different platforms. These models have been integrated in order to be able to perform component, subsystem, and system analyses as well as develop optimal syntheses/designs and control strategies for transportation and stationary SOFC based APUs. Some pertinent results of these efforts are presented here.

Analysis of Control Strategy for Extended-Range Electric Vehicle

2011 ◽  
Vol 135-136 ◽  
pp. 261-267
Author(s):  
Hai Tao Min ◽  
Dong Jin Ye ◽  
Yuan Bin Yu
Keyword(s):  
Electric Vehicles ◽  
Control Strategy ◽  
Optimal Strategy ◽  
Control Strategies ◽  
Power Train ◽  
Operating Modes ◽  
Load Following ◽  
Extended Range ◽  
Main Components ◽  
And Control

This paper introduced the structure of Extended-Range Electric Vehicles as well as its characteristics. Principle researches have been offered on the parameters matching of the power-train and main components. Operating modes and control strategies were discussed, especially the two control strategies of charge sustaining mode which is shown as load following strategy and engine optimal strategy, and the effects of both control strategies are simulated and analyzed. The results indicate that the load following strategy can obviously extend battery’s lifespan, but the engine optimal strategy can reduce fuel consumption and emission effectively.

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