scholarly journals Linearized Discrete Charge Balance Control with Simplified Algorithm for DCM Buck Converter

Energies ◽  
2019 ◽  
Vol 12 (16) ◽  
pp. 3177 ◽  
Author(s):  
Run Min ◽  
Dian Lyu ◽  
Shuai Cheng ◽  
Yingshui Sun ◽  
Linkai Li
Keyword(s):  
Control Strategy ◽  
Balance Control ◽  
Buck Converter ◽  
Linear Control ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Small Signal ◽  
Charge Balance ◽  
Control Approach ◽  
Discrete Charge

In this paper, a linearized discrete charge balance (LDCB) control strategy is proposed for buck converter operating in discontinuous conduction mode (DCM). For DC-DC power converters, discrete charge balance (DCB) control is an attractive approach to improve the output voltage transient response. However, as a non-linear control strategy, the algorithm is complex, which is difficult for implementation. To reduce the complexity, this paper proposes the LDCB control strategy that is derived through linearizing conventional DCB controller. By deriving the differential functions of the DCB control algorithm, the small signal relationship between the input and output of DCB controller is explored. Furthermore, based on the relationship, the LDCB controller is formed through three parallel feed loops to the duty ratio. As a linear control approach, the achieved LDCB controller is greatly simplified for implementation. This not only saves the hardware cost, but also reduces the calculation lag, which provides potential to improve the switching frequency. Besides, since the LDCB controller shares the same small signal model as that of DCB controller, it achieves similar control loop bandwidth and transient performance. Effectiveness of the proposed LDCB control is verified by zero/pole plots, transient analyses and experimental results.

scholarly journals Adaptive Feedback Control for a Pasteurization Process

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 930
Author(s):  
Emil D.J. Rasmussen ◽  
Massimiliano Errico ◽  
Stefania Tronci
Keyword(s):  
Control Strategy ◽  
Adaptive Algorithm ◽  
Pid Controller ◽  
Linear Control ◽  
Control Algorithms ◽  
Time Varying ◽  
Control Parameters ◽  
Adaptive Feedback ◽  
Control Approach ◽  
Adaptive Feedback Control

The milk pasteurization process is nonlinear in nature, and for this reason, the application of linear control algorithms does not guarantee the obtainment of the required performance in every condition. The problem is here addressed by proposing an adaptive algorithm, which was obtained by starting from an observer-based control approach. The main result is the obtainment of a simple PI-like controller structure, where the control parameters depend on the state of the system and are adapted online. The proposed algorithm was designed and applied on a simulated process, where the temperature dependence of the milk’s physical properties was considered. The control strategy was tested by simulating different situations, particularly when time-varying disturbances entered the system. The use of the adaptive rule reduces the variance generally introduced by the PI or PID controller.

The Control Strategy of Establishing the Voltage of DC Side in MMC

2013 ◽  
Vol 756-759 ◽  
pp. 292-297
Author(s):  
Ming Ma ◽  
Gang Peng ◽  
Jun Wei Hao ◽  
Jing Jing Lu ◽  
Chang Yuan ◽  
...  
Keyword(s):  
Control Strategy ◽  
Balance Control ◽  
Voltage Control ◽  
Switching Frequency ◽  
Switching Loss ◽  
Dc Voltage ◽  
High Switching Frequency ◽  
Voltage Balance ◽  
Dc Voltage Control ◽  
Voltage Balance Control

This paper discusses the establishing method of DC voltage of modular multilevel converter (MMC). Firstly the structure of MMC and the charging principle of sub-modules (SMs) are introduced in order to control the DC voltage of MMC and reduce the switching loss. It is pointed out that the DC voltage control in MMC includes two parts, the DC voltage establishment of system and the voltages control of SMs. For the DC voltage control in system, the control theory is analyzed, and the corresponding control strategy is proposed. Meanwhile an improved voltage balance control strategy for SM is proposed by the improvements of the traditional voltage sorting method to reduce the high switching frequency caused by the blind action of switching devices in the SM control. Finally, the simulation results based on PSCAD/EMTDC show that DC voltage in MMC can run in the rated value steadily, and the switching frequency is reduced significantly.

scholarly journals Equivalent Two Switches and Single Switch Buck/Buck-Boost Circuits for Solar Energy Harvesting Systems

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 583
Author(s):  
Ehsan Jamshidpour ◽  
Slavisa Jovanovic ◽  
Philippe Poure
Keyword(s):  
Output Voltage ◽  
Experimental Tests ◽  
Buck Converter ◽  
Maximum Power ◽  
Duty Ratio ◽  
Switching Frequency ◽  
Level Control ◽  
Voltage Level ◽  
Synchronous Control ◽  
Solar Energy Harvesting

In this paper, a comparative analysis has been presented of two equivalent circuits of non-isolated buck/buck-boost converters under synchronous control, used in a stand-alone Photovoltaic-battery-load system. The first circuit consists of two cascaded buck and buck-boost classical converters with two controllable switches. The buck converter is used to extract the maximum power of the Photovoltaic source, and the buck-boost converter is applied for the output voltage level control. The second circuit consists of a proposed converter with a single controllable switch. In both cases, the switching frequency is used to track the maximum power point and the duty ratio controls the output voltage level. Selected simulation results and experimental tests confirm that the two conversion circuits have identical behavior under synchronous control. This study shows that the single switch converter has a lower size and cost, but it is limited in the possible control strategy.

Asymmetric Cascaded DC Sources Multilevel Inverter with Less Active Switches and Simpler Control Strategy

2015 ◽  
Vol 785 ◽  
pp. 111-115
Author(s):  
Yee Chyan Tan ◽  
Syed Idris Syed Hassan ◽  
Siok Lan Ong ◽  
Jenn Hwai Leong
Keyword(s):  
Control Strategy ◽  
Output Voltage ◽  
Balance Control ◽  
Multilevel Inverter ◽  
Solar Pv ◽  
Charge Balance ◽  
Dc Voltage ◽  
Pv Systems ◽  
Charge Balancing ◽  
Balancing Control

Cascaded H-Bridge (CHB) multilevel inverter (MLI) is among the most preferred topology in solar PV systems. While traditional asymmetric CHB MLI is easy to achieve higher number of output voltage levels compared to traditional symmetric CHB MLI, charge balancing between the voltage sources remains a challenge for asymmetric CHB MLI. This drawback results in unsteady DC voltage levels due to unbalanced power drawn from each voltage sources. Besides that, in battery powered applications, unbalanced power drawn results in unequal discharged among the batteries. In this paper, an asymmetric half H-bridge (HHB) MLI topology is presented which is easy to modularize as for symmetric CHB MLI while maintaining the ease in charge balancing control. The performance of this proposed asymmetric HHB MLI with charge balance control has been evaluated using PSIM software.

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