scholarly journals Dynamic Improvement with a Feedforward Control Strategy of Bidirectional DC-DC Converter for Battery Charging and Discharging

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1738
Author(s):  
Jingang Han ◽  
Xin Gu ◽  
Yi Yang ◽  
Tianhao Tang
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Power Flow ◽  
Control Method ◽  
Feedforward Control ◽  
Duty Ratio ◽  
Pi Control ◽  
Battery Charging ◽  
Voltage Range ◽  
Rapid Current

With the increasing importance of power accumulator batteries in electric vehicles, the accurate characteristics of power accumulator batteries have an important role. In order to evaluate the power accumulator battery, battery charging and discharging is indispensable. In this article, a H-bridge bidirectional DC-DC converter is presented which can charge and discharge the battery with different voltage levels and one of the merits of this topology is that a wide output voltage range can be easily achieved. In the control part, a proportional-integral (PI) control strategy is adopted to ensure a stable and reliable operation of the converter. Furthermore, compared with the PI control strategy, a duty ratio feedforward control is utilized to obtain the rapid current dynamic response. In this article, firstly, the system configuration for battery charging and discharging is introduced, then the operating principles and mathematical model of the DC-DC converter are analyzed and derived. Secondly, for bidirectional DC-DC converters, the PI control method and duty ratio feedforward control method are put forward and designed. Finally, the simulation model is established based on PSIM software and the experiment platform is also built in lab. The results of the simulation and experiment research show that the H-bridge bidirectional DC-DC converter can operate reliably and stably during the charging, discharging and power flow reverse modes. In addition, the dynamic response of the charging and discharging current can also be further improved by introducing the duty ratio feedforward control method.

Performance Improvement of SVPWM-Based Three-Phase Grid-Connected Inverters

2013 ◽  
Vol 732-733 ◽  
pp. 1261-1264
Author(s):  
Zhi Lei Yao ◽  
Lan Xiao ◽  
Jing Xu
Keyword(s):  
Dynamic Response ◽  
Control Strategy ◽  
Pulse Width Modulation ◽  
Control Method ◽  
Grid Current ◽  
Current Controller ◽  
Three Phase ◽  
Reference Grid ◽  
Grid Connected Inverter

An improved control strategy for three-phase grid-connected inverters with space vector pulse width modulation (SVPWM) is proposed. When the grid current contains harmonics, the d-and q-axes grid currents is interacted in the traditional control method, and the waveform quality of the grid current is poor. As the reference output voltage cannot directly reflect the change of the reference grid current with the traditional control strategy, the dynamic response of the grid-connected inverter is slow. In order to solve the aforementioned problems, the d-and q-axes grid currents in the decoupled components of the grid current controller are substituted by the d-and q-axes reference grid currents, respectively. The operating principles of the traditional and proposed control methods are illustrated. Experimental results show that the grid-connected inverter with the improved control strategy has high waveform quality of the grid current and fast dynamic response.

scholarly journals Comprehensive Power Flow Analyses and Novel Feedforward Coordination Control Strategy for MMC-Based UPFC

Energies ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 824 ◽  
Author(s):  
Jinlian Liu ◽  
Zheng Xu ◽  
Liang Xiao
Keyword(s):  
Power Systems ◽  
Control Strategy ◽  
Computer Aided Design ◽  
Power Flow ◽  
Feedforward Control ◽  
Control Strategies ◽  
Dynamic Performance ◽  
Unified Power Flow Controller ◽  
3 Dimensional ◽  
Steady State Operation

This paper aims to discover the general steady-state operation characteristics, as well as improving the dynamic performance, of the modular multilevel converter (MMC)-based unified power flow controller (UPFC). To achieve this, first, we established a detailed power flow model for MMC-based UPFC containing each critical part and made qualitative and graphical analyses combining 2-dimensional operation planes and 3-dimensional spatial curve surfaces comprehensively to derive general power flow principles and offer necessary references for regulating UPFC. Furthermore, to achieve better performance, we designed a feedforward control strategy for the shunt and series converters of UPFC, both comprising two feedforward control blocks with the introduction of necessary compensating branches, and analyzed the performance in complex and time domain, respectively. The proposed power flow principles and control strategies were validated by a (power systems computer aided design) PSCAD model of 220 kV double-end system; the results reveal the MMC-based UPFC can realize the power flow principles and improve the control speed, stability, and precision of the power flow regulations under various conditions.

scholarly journals A Novel Control Strategy for PV/Wind/Battery Hybrid System Using High Gain Boost Converter

2021 ◽  
Vol 7 (03) ◽  
pp. 295-303
Keyword(s):  
Energy Management ◽  
Control Strategy ◽  
Maximum Power Point Tracking ◽  
Maximum Power ◽  
Pi Control ◽  
Maximum Power Point ◽  
Battery Charging ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Power Point

In this paper, a classic proportional–integral (PI) control strategy as an energy management strategy (EMS) and a microgrid stand-alone power system configuration are proposed to work independently out of grid. The proposed system combines photovoltaics (PVs), and Battery. The system supplies a dump load with its demand power. The system includes DC/DC and DC/AC converters, as well as a maximum power point tracking (MPPT) to maximize the harvested energy from PV array. The classic PI control strategy is used to control the main system parameters like state-of-charge (SOC) for the battery. The corresponding energy management and control strategy are proposed to realize the power balance among three ports in different operating scenarios, which comprehensively takes both the maximum power point tracking (MPPT) benefit and the battery charging/discharging management into consideration. The simulations are conducted using the Matlab/Simulink software to verify the operation performance of the proposed PV/battery hybrid distributed power generation system with the corresponding control algorithms, where the MPPT control loop, the battery charging/discharging management loop are enabled accordingly in different operating scenarios.

scholarly journals Bleed Air Temperature Regulation System: Modeling, Control, and Simulation

2021 ◽  
Author(s):  
Peter Hodal
Keyword(s):  
Heat Exchanger ◽  
Temperature Control ◽  
Control Strategy ◽  
Temperature Regulation ◽  
Control Method ◽  
System Modeling ◽  
Regulation System ◽  
Pi Control ◽  
Air System ◽  
Control Configuration

This thesis addresses temperature control of an engine bleed air system, as used on typical aircraft, with a control strategy aimed at reducing ram air usage while maintaining fast response. The analytical equations describing the system dynamics are presented, and a state space model of a cross-flow heat exchanger is developed. The heat exchanger model is then utilized in the modeling of the bleed air system under study. Different control strategies and configurations are analyzed and compared. In order to achieve fast temperature regulation while saving ram air usage, a ram-air-plus-bypass control configuration is proposed, along with the control of both load temperature and bypass valve opening. Classical PI control is employed, and a hybrid LQ/PI control method is additionally investigated for the proposed control configuration. Simulations for each control strategy are performed using a nonlinear dynamic model at several sample mission operating points, with consideration of disturbances in engine loading of ambient conditions. Comparisons are made and conclusions are drawn based on these simulations. The proposed configuration and control strategy prove to be more effective in terms of satisfying both low ram air usage and fast temperature control response.

scholarly journals A Fuzzy Drive Strategy for an Intelligent Vehicle Controller Unit Integrated with Connected Data

Machines ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 215
Author(s):  
Luyao Du ◽  
Jun Ji ◽  
Donghua Zhang ◽  
Hongjiang Zheng ◽  
Wei Chen
Keyword(s):  
Dynamic Response ◽  
Early Warning ◽  
Control Strategy ◽  
Control Method ◽  
Vehicle Control ◽  
Intelligent Vehicle ◽  
Accelerator Pedal ◽  
Drive Control ◽  
Level Model ◽  
Opening And Closing

In order to improve vehicle control safety in intelligent and connected environments, a fuzzy drive control strategy is proposed. Through the fusion of vehicle driving data, an early warning level model was established, and the fuzzy control method was used to obtain the appropriate torque command under the vehicle condition; torque optimization processing was performed according to the different corresponding vehicle following characteristics. The control strategy was tested and verified on an established platform. Based on the experimental results, compared with the traditional drive strategy in one-way front and rear following scenarios, the vehicle avoided excessive opening and closing of the accelerator pedal when the distance between vehicles was close, maintained the correct distance in the following situation, and had better dynamic response when the distance between vehicles was large, indicating that the proposed drive strategy had a better real-time and security performance.

Control Strategy of Microgrid Based on Distributed Generation

2012 ◽  
Vol 430-432 ◽  
pp. 1277-1280
Author(s):  
Yao Zhao ◽  
Ru Qi Cheng ◽  
Xin Gong ◽  
Geng Shen Zhao
Keyword(s):  
Distributed Generation ◽  
Control Strategy ◽  
Power Flow ◽  
Control Method ◽  
Operation Mode ◽  
Experimental System ◽  
Control Unit ◽  
Energy Utilization ◽  
Control Mode ◽  
Power Point

Upon the traditional wind-solar hybrid distributed generation system,a single-phase microgrid experimental system platform has been built based on the DC bus,Z topology was used to increase the energy utilization ratio. On the basic of realizing the maximum power point tracker of the new energy, different microgrid controlling strategy has been designed to apply to the island and grid connected operation mode: in the cases of island running, master slave control mode will be utilized in the system and the battery will be used as the main control unit to provide the reference voltage; on the other hand, a control method which can merge the generation into the grid as much as possible will be adopted in the case of grid connected. By the use of system model, the simulation of the two operation mode switch state and power flow has been done and the feasibility and effectiveness of the control strategy can be guaranteed,it also has been verified by the microgrid experimental platform.

scholarly journals Modified Smith Predictor Based on H 2 and Predictive PI Control Strategy

2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Shiqing Sang ◽  
Pengcheng Nie
Keyword(s):  
Time Delay ◽  
Control Strategy ◽  
Control Algorithm ◽  
Control Method ◽  
Order Approximation ◽  
Current System ◽  
Smith Predictor ◽  
Pi Control ◽  
Delay Term ◽  
Modified Smith Predictor

In this paper, a new type of modified Smith predictor based on the H 2 and predictive PI control strategy is proposed. The modified Smith predictor not only has H 2 robust performance but also has a similar predictive PI control structure. By introducing a time delay term, the modified Smith predictor controller overcomes the shortcoming that the conventional control algorithm can only use the low-order approximation of time delay term to design the control algorithm. The modified Smith predictor controller’s output is related to the current system error and related to the output in a period before the controller. Simultaneously, the modified Smith predictor controller is applied to conventional process systems based on dynamic optimization estimation in the case study to show absolute superiority over the nonpredictive control method (such as the classical PID control method).

scholarly journals Strategi Pengisian Baterai pada Sistem Panel Surya Standalone Berbasis Kontrol PI Multi-Loop

2021 ◽  
Vol 13 (1) ◽  
pp. 25-33
Author(s):  
Khusnul Hidayat ◽  
Mohammad Chasrun Hasani ◽  
Nur Alif Mardiyah ◽  
Machmud Effendy
Keyword(s):  
Control Strategy ◽  
Power Flow ◽  
Control Method ◽  
Life Time ◽  
Balance Of Power ◽  
High Current ◽  
Loop Control ◽  
Maximum Charge ◽  
Charging Current ◽  
Dc Bus

This study discusses the power control strategy in a standalone photovoltaic-battery hybrid system. The life-time of the battery will be shorter if the battery is often charged with high current and exceeds its State-of-Charge (SoC). Therefore, a control method is needed to control the power flow on the DC bus and the charging current as well as the SoC of the battery so that the battery has a long life-time. The proposed system uses two dc-dc converters to connect photovoltaic (PV) and lead-acid batteries to the load. The unidirectional DC-DC converter is used as the interface between the PV and the DC bus, the bidirectional DC-DC converter is used as the interface between the battery and the DC bus. The control strategy plays a role in controlling the power flow between the converter and the load to maintain the balance of power in the system and controlling the battery to support PV when the available PV power is not enough to meet the load. The multi-loop control strategy is proposed in this study, one of the loops is used to maintain the SoC of the battery in order to control the PV output power to avoid over-charging. Another loop is used to ensure the balance of the system's power when the battery is charging at its maximum charge current. The proposed control system is implemented without requiring any conditions for the control to operate. The simulation results show that the proposed multi-loop control can control the power flow in the system while maintaining the maximum charging current and battery SoC limits.

scholarly journals Bleed Air Temperature Regulation System: Modeling, Control, and Simulation

2021 ◽  
Author(s):  
Peter Hodal
Keyword(s):  
Heat Exchanger ◽  
Temperature Control ◽  
Control Strategy ◽  
Temperature Regulation ◽  
Control Method ◽  
System Modeling ◽  
Regulation System ◽  
Pi Control ◽  
Air System ◽  
Control Configuration

This thesis addresses temperature control of an engine bleed air system, as used on typical aircraft, with a control strategy aimed at reducing ram air usage while maintaining fast response. The analytical equations describing the system dynamics are presented, and a state space model of a cross-flow heat exchanger is developed. The heat exchanger model is then utilized in the modeling of the bleed air system under study. Different control strategies and configurations are analyzed and compared. In order to achieve fast temperature regulation while saving ram air usage, a ram-air-plus-bypass control configuration is proposed, along with the control of both load temperature and bypass valve opening. Classical PI control is employed, and a hybrid LQ/PI control method is additionally investigated for the proposed control configuration. Simulations for each control strategy are performed using a nonlinear dynamic model at several sample mission operating points, with consideration of disturbances in engine loading of ambient conditions. Comparisons are made and conclusions are drawn based on these simulations. The proposed configuration and control strategy prove to be more effective in terms of satisfying both low ram air usage and fast temperature control response.

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