scholarly journals Efficacy of STC in Magnetically Coupled High Frequency Power Electronics Systems: Full-Bridge DC-DC Converter

2021 ◽  
Author(s):  
Arun Paul
Keyword(s):  
Power Electronics ◽  
Sliding Mode ◽  
Coupled System ◽  
High Gain ◽  
Worst Case ◽  
Switching Losses ◽  
Great Hope ◽  
Design Cycle ◽  
Adoption And Diffusion ◽  
Twisting Control

Due to its simple gain selection and implementation procedures high-gain sliding mode control idea was introduced. Apart from achieving robustness features, the aim was to reduce product-design cycle time. To overcome its basic chattering issues, it was replaced by complex super twisting control (STC). Subsequently, the research in this field has been extensive, intense and persistent. The idea has been validated in several applications generating great hope in minds of industry experts. Its real success, however, would depend on its adoption and diffusion into industry domain, where an analysis of validating STC based products is due. In STC, selection of gains is based on worst-case values of disturbance and/or its derivative. Can such procedure ensure controller’s reliable functioning? This article proposes that such simplistic procedure of gain selection may not work for power electronics controllers where, particularly, the actuation or controlled power transfer to load is through magnetically-coupled system. Using practical approach, this article elaborates that optimally designed transformer, driven by high-gain super twisting controller, invites problem of core saturation leading to higher switching losses, poor operating duty cycle of the system and there could be problem of reliability. It further details an alternate high-gain controller that generates superior efficacy.

scholarly journals Efficacy of STC in Magnetically Coupled High Frequency Power Electronics Systems: Full-Bridge DC-DC Converter

2021 ◽  
Author(s):  
Arun Paul
Keyword(s):  
Power Electronics ◽  
Sliding Mode ◽  
Coupled System ◽  
High Gain ◽  
Worst Case ◽  
Switching Losses ◽  
Great Hope ◽  
Design Cycle ◽  
Adoption And Diffusion ◽  
Twisting Control

Due to its simple gain selection and implementation procedures high-gain sliding mode control idea was introduced. Apart from achieving robustness features, the aim was to reduce product-design cycle time. To overcome its basic chattering issues, it was replaced by complex super twisting control (STC). Subsequently, the research in this field has been extensive, intense and persistent. The idea has been validated in several applications generating great hope in minds of industry experts. Its real success, however, would depend on its adoption and diffusion into industry domain, where an analysis of validating STC based products is due. In STC, selection of gains is based on worst-case values of disturbance and/or its derivative. Can such procedure ensure controller’s reliable functioning? This article proposes that such simplistic procedure of gain selection may not work for power electronics controllers where, particularly, the actuation or controlled power transfer to load is through magnetically-coupled system. Using practical approach, this article elaborates that optimally designed transformer, driven by high-gain super twisting controller, invites problem of core saturation leading to higher switching losses, poor operating duty cycle of the system and there could be problem of reliability. It further details an alternate high-gain controller that generates superior efficacy.

scholarly journals Efficacy of STC in Magnetically Coupled High Frequency Power Electronics Systems: Full-Bridge DC-DC Converter

2021 ◽  
Author(s):  
Arun Paul
Keyword(s):  
Power Electronics ◽  
Sliding Mode ◽  
Coupled System ◽  
High Gain ◽  
Worst Case ◽  
Switching Losses ◽  
Great Hope ◽  
Design Cycle ◽  
Adoption And Diffusion ◽  
Twisting Control

Due to its simple gain selection and implementation procedures high-gain sliding mode control idea was introduced. Apart from achieving robustness features, the aim was to reduce product-design cycle time. To overcome its basic chattering issues, it was replaced by complex super twisting control (STC). Subsequently, the research in this field has been extensive, intense and persistent. The idea has been validated in several applications generating great hope in minds of industry experts. Its real success, however, would depend on its adoption and diffusion into industry domain, where an analysis of validating STC based products is due. In STC, selection of gains is based on worst-case values of disturbance and/or its derivative. Can such procedure ensure controller’s reliable functioning? This article proposes that such simplistic procedure of gain selection may not work for power electronics controllers where, particularly, the actuation or controlled power transfer to load is through magnetically-coupled system. Using practical approach, this article elaborates that optimally designed transformer, driven by high-gain super twisting controller, invites problem of core saturation leading to higher switching losses, poor operating duty cycle of the system and there could be problem of reliability. It further details an alternate high-gain controller that generates superior efficacy.

Sliding-mode observers for systems with unknown inputs: A high-gain approach

Automatica ◽  
2010 ◽  
Vol 46 (2) ◽  
pp. 347-353 ◽  
Author(s):  
Karanjit Kalsi ◽  
Jianming Lian ◽  
Stefen Hui ◽  
Stanislaw H. Żak
Keyword(s):  
Sliding Mode ◽  
High Gain ◽  
Unknown Inputs ◽  
Sliding Mode Observers

Average Modeling and Nonlinear Observer Design For Pneumatic Actuators With On/Off Solenoid Valves

2021 ◽  
Author(s):  
Khaled Laib ◽  
Minh Tu Pham ◽  
Xuefang LIN-SHI ◽  
Redha Meghnous
Keyword(s):  
Closed Loop ◽  
Sliding Mode ◽  
High Gain ◽  
Observer Design ◽  
Nonlinear Observer ◽  
State Model ◽  
Pressure Measurements ◽  
Pneumatic Actuators ◽  
Nonlinear Observers ◽  
Piston Position

Abstract This paper presents an averaged state model and the design of nonlinear observers for an on/off pneumatic actuator. The actuator is composed of two chambers and four on/off solenoid valves. The elaborated averaged state model has the advantage of using only one continuous input instead of four binary inputs. Based on this new model, a high gain observer and a sliding mode observer are designed using the piston position and the pressure measurements in one of the chambers. Finally, their closed-loop performances are verified and compared on an experimental benchmark.

scholarly journals The role of magnetic sensors in the hybridisation and electrification of vehicles

2019 ◽  
Author(s):  
Marc Kramb ◽  
Rolf Slatter
Keyword(s):  
Power Electronics ◽  
Causal Chain ◽  
Rogowski Coil ◽  
Magnetic Sensors ◽  
Current Sensor ◽  
Electrical Currents ◽  
Limited Bandwidth ◽  
Switching Losses ◽  
Current Sensors ◽  
Rogowski Coils

Electrical currents need to be measured in a wide variety of different applications in the field of power electronics. However, the requirements for these measurement devices are becoming steadily more demanding regarding accuracy, size and especially bandwidth. In order to increase the power density of power electronics, as particularly important in the field of electromobility, there is a clear causal chain. Soft switching leads to higher efficiency and higher frequencies, which enable smaller dimensions for a given power output. Higher switching frequencies allow the size of magnetic components to be reduced significantly, resulting in more compact and lighter designs. This trend is now being reinforced by use of new wide bandgap semiconductor materials like silicon carbide (SiC) and gallium nitride (GaN), as their low on-resistances and low parasitic capacitances reduce switching losses. Conventional current sensor solutions, e.g. hallor shunt based sensors exhibit a limited bandwidth, typically less than 250 kHz. Other current sensors, like those based on the Rogowski-Coil, are capable of highly dynamic current measurement, but are significantly more expensive, larger and hence not suitable for large series applications. Furthermore, Rogowski-Coils are only capable of measuring alternating currents (AC), which prevents their use in applications where DC currents must also be measured. In order to meet the above mentioned requirements, magnetoresistive (MR) current sensors are ideally suited due to the fact that the bandwidth of the magnetoresistive effect extends up into the GHz-range. This paper describes the principle of operation and main performance characteristics of highly integrated MR current sensors and describes their benefits compared to other types of current sensor, in particular with regard to applications in the hybridisation and electrification of vehicles.

Observer-based nonlinear precise control of pneumatic servo systems

2018 ◽  
Vol 233 (2) ◽  
pp. 165-176 ◽  
Author(s):  
Sepehr Ramezani ◽  
Keivan Baghestan
Keyword(s):  
Sliding Mode ◽  
Nonlinear Modeling ◽  
High Gain ◽  
Good Choice ◽  
Servo Systems ◽  
Precise Position ◽  
Precise Control ◽  
Automation Systems ◽  
Wide Range ◽  
The Cost

Pneumatic systems are used in a wide range of industrial robotic and automation systems due to their interesting properties. However, air compressibility, friction, and the other nonlinear characteristics of a servo pneumatic system are difficulties, which contribute to use modern controllers. Conventional linear controllers face steady-state error and uncertainty. Nonlinear modeling with model-based control is a good choice to deal with this problem. In this paper, behavior equation of flow and pressure, friction, and other nonlinear factors are studied. Afterward to reach precise position tracking and low steady error, sliding mode control is proposed. In this way, measurement of pressures and other states of system is required. To reduce the cost of using pressure sensor, observation of pressure with nonlinear high gain observer is suggested. It was seen that the new proposed approach solved the observability problem of servo pneumatic systems. Pressure signal of each sides of cylinder are observed simultaneously by measurement of piston position. Finally, stability of designed controller is studied in the presence of observed states. Experimental results validate the advantage of using designed controller-observer instead of conventional proportional–integral–derivative controller with different input signals in the presence of high friction actuator.

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