A Space Vector Switching Pattern Hysteresis Control Strategy in VIENNA Rectifier

Lee

et al. 2021

Sensors

Typically, the actual volume of the residual limb changes over time. This causes the prosthesis to not fit, and then pain and skin disease. In this study, a prosthetic socket was developed to compensate for the volume change of the residual limb. Using an inflatable air bladder, the proposed socket monitors the pressure in the socket and keeps the pressure distribution uniform and constant while walking. The socket has three air bladders on anterior and posterior tibia areas, a latching type 3-way pneumatic valve and a portable control device. In the paper, the mechanical properties of the air bladder were investigated, and the electromagnetic analysis was performed to design the pneumatic valve. The controller is based on a hysteresis control algorithm with a closed loop, which keeps the pressure in the socket close to the initial set point over a long period of time. In experiments, the proposed prosthesis was tested through the gait simulator that can imitate a human’s gait cycle. The active volume compensation of the socket was successfully verified during repetitive gait cycle using the weight loads of 50, 70, and 90 kg and the residual limb model with a variety of volumes. It was confirmed that the pressure of the residual limb recovered to the initial state through the active control. The pressure inside the socket had a steady state error of less than 0.75% even if the volume of the residual limb was changed from −7% to +7%.

Section: Methodsmentioning

confidence: 99%

A Prosthetic Socket with Active Volume Compensation for Amputated Lower Limb

Lee

et al. 2021

Sensors

“…The PI control [13]- [15] is a traditional control strategy for power electronic switching circuits, but it is difficult to achieve zero-error tracking on the alternating current (AC) side and it has poor dynamic response on the DC side. The hysteresis control [16] is easy to implement, nevertheless, its switching frequency instability will affect the stability of the system. Model predictive control [17]- [19] can combine modulation with control, but it has a more serious delay problem.…”

Section: Introductionmentioning

confidence: 99%

Sliding Mode Control of Vienna Rectifier Under Unbalanced Weak Power Grid

Tian,

Yuan,

Zhu

et al. 2024

IEEE Access

Three-phase, three-level Vienna rectifiers are widely used in power supplies for the advantages of high power density, low switching voltage stress and low grid side current harmonics. However, due to the presence of positive and negative sequence components under the unbalanced weak power grid, the control structure using the traditional proportional integral (PI) control is complicated and requires decoupling and multiple coordinate transformations, and it has longer dynamic response time. This paper presents an unbalanced current control strategy that combines improved sliding mode control (SMC) with new reaching law and multi proportional resonance (MPR) control of Vienna rectifier under unbalanced weak power grid. This paper establishes the mathematical model of Vienna rectifier under unbalanced weak current network. In the αβ coordinate system, dual second-order generalized integrator (DSOGI) is used to separate the positive and negative sequence components of the voltage. Suitable sliding mode surfaces and sliding mode convergence laws were designed. Finally, the results of simulations and experiments were used to verify the effectiveness of the proposed method.INDEX TERMS multiple proportional resonant (MPR) control, positive and negative sequence separation, second harmonic components, sliding mode control (SMC), unbalanced weak power grid

IET Renewable Power Gen

“…A Thermal Electrical Energy Conversion (TEEC) system is used to transform thermal into electrical energy. In the TEEC established on linear generator power, electronic converters meet the load requirements [8,9].…”

Section: Introductionmentioning

confidence: 99%

Rectification and converter control of the FPSLGs for energy storage applications

Ali,

Haitao,

Mobayen

et al. 2024

This article presents two power converters with controllers attached to the Free‐Piston Stirling Linear Generator (FPSLG) and energy storage system (ESS). The rectifier uses hysteresis‐SVPWM current regulation and CB‐SPWM, while the buck‐boost converter utilizes the dual‐loop PI control method. The storage battery receives energy from a linear‐generator with a rectifier and converter. The FPSE and linear motors in the FPSLG convert thermal to electrical energy. A two‐level electrical energy conversion technique using a three‐phase AC signal to DC and DC‐DC converter has been devised to reduce output electrical energy oscillation as well as stabilize the generating system's DC power. Initially, the FPSE's nonlinear model and the three‐phase permanent magnet linear‐motor's linear mathematical model were created and followed by the ESS and control mechanism simulation. The simulation shows that the ESS system and control approach can give stable power to the storage battery using linear‐generator power. The PR controller replaces the PI controller in the position loop to improve frequency and displacement tracing. The control system design was simulated in MATLAB and the topology's feasibility and correctness were confirmed. Comparative analysis shows that, rectifier uses the H‐SVPWM's unity power factor of AC and stability controllability of the DC‐side voltage is better than the CB‐SPWM approach.