scholarly journals Discrete Fundamental AC Voltage Controller for Three-Phase Standalone Converters

Energies ◽  
2021 ◽  
Vol 14 (3) ◽  
pp. 650
Author(s):  
Alejandro García-Fernández ◽  
Jesús Doval-Gandoy ◽  
Diego Pérez-Estévez
Keyword(s):  
State Space ◽  
Closed Loop ◽  
Design Procedure ◽  
Pole Placement ◽  
Discrete State ◽  
Voltage Controller ◽  
Three Phase ◽  
Wide Range ◽  
Lc Filter ◽  
Output Filter

Voltage control of standalone converters with LC filter is usually based on proportional-resonant or proportional-integral controllers, which often require further active damping methods to achieve stability. These solutions place design constraints in the selection of the closed-loop pole locations which limit the achievable bandwidth and increase the design complexity. In contrast, in state-space based controllers, the closed-loop poles can be placed freely through state feedback, which makes them particularly suitable for high order plants and/or low sampling frequencies. Among the modern control methods, direct pole placement is a simple technique that enables the establishment of a straightforward relationship between outcome and design, as opposed to more advanced approaches. This paper presents a discrete state-space voltage controller for standalone converters with LC output filter. The proposed method combines the direct pole placement technique with a virtual disturbance observer in order to compensate the effects produced by the load and model mismatches. The design process takes into account both the filter parameters and the sampling frequency, rendering the performance of the obtained controller independent of both. The result is a streamlined design procedure that leads to consistent outcomes for a wide range of plant parameter variations, requiring only one input: the desired closed-loop bandwidth.

scholarly journals DQ-Frame Admittance Estimation of Three-Phase Converters with a Wide Range of Operating Points

2021 ◽  
Author(s):  
Hong Gong ◽  
xiongfei wang ◽  
Dongsheng Yang
Keyword(s):  
Error Estimation ◽  
Closed Loop ◽  
Estimation Method ◽  
Experimental Results ◽  
Multidimensional Interpolation ◽  
Three Phase ◽  
Wide Range ◽  
Linearized Model ◽  
Operating Points ◽  
Error Estimation Method

The <i>dq</i>-frame admittance of closed-loop controlled three-phase converters is a linearized model that is dependent on the operating points of the system. Yet, it is impractical to measure the converter admittance at all operating points. This paper, thus, proposes an approach to estimating the <i>dq</i>-frame admittance of three-phase converters at a wide range of operating points. The method applies multidimensional interpolation to a given set of admittance data, which is measured from the pre-defined operating points. The accuracy of interpolation is then evaluated by using the posterior error estimation method. The number of pre-defined operating points is next adjusted to find a good compromise between the accuracy and efficiency of the approach. Simulations and experimental results verify the effectiveness of the approach.<div><br></div>

scholarly journals Real-Time Low-Cost Speed Monitoring and Control of Three-Phase Induction Motor via a Voltage/Frequency Control Approach

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Ali Hmidet ◽  
Olfa Boubaker
Keyword(s):  
Real Time ◽  
Induction Motor ◽  
Closed Loop ◽  
Low Cost ◽  
Closed Loop Control ◽  
Loop Control ◽  
Control Approach ◽  
Three Phase ◽  
Wide Range ◽  
Voltage Frequency

In this paper, a new design of a real-time low-cost speed monitoring and closed-loop control of the three-phase induction motor (IM) is proposed. The proposed solution is based on a voltage/frequency (V/F) control approach and a PI antiwindup regulator. It uses the Waijung Blockset which considerably alleviates the heaviness and the difficulty of the microcontroller’s programming task incessantly crucial for the implementation and the management of such complex applications. Indeed, it automatically generates C codes for many types of microcontrollers like the STM32F4 family, also used in this application. Furthermore, it offers a cost-effective design reducing the system components and increasing its efficiency. To prove the efficiency of the suggested design, not only simulation results are carried out for a wide range of variations in load and reference speed but also experimental assessment. The real-time closed-loop control performances are proved using the aMG SQLite Data Server via the UART port board, whereas Waijung WebPage Designer (W2D) is used for the web monitoring task. Experimental results prove the accuracy and robustness of the proposed solution.

scholarly journals From Beale Number to Pole Placement Design of a Free Piston Stirling Engine

2017 ◽  
Vol 64 (4) ◽  
pp. 499-518 ◽  
Author(s):  
Shahryar Zare ◽  
Alireza Tavakolpour-Saleh ◽  
Amir Omidvar
Keyword(s):  
Closed Loop ◽  
Design Procedure ◽  
Stirling Engine ◽  
Pole Placement ◽  
Design Parameters ◽  
Dynamic Systems Theory ◽  
Design Technique ◽  
Free Piston ◽  
Frictional Damping ◽  
Free Piston Stirling Engine

Abstract In this paper, pole placement-based design and analysis of a free piston Stirling engine (FPSE) is presented and compared to the well-defined Beale number design technique. First, dynamic and thermodynamic equations governing the engine system are extracted. Then, linear dynamics of the free piston Stirling engine are studied using dynamic systems theory tools such as root locus. Accordingly, the effects of variations of design parameters such as mass of pistons, stiffness of springs, and frictional damping on the locations of dominant closed-loop poles are investigated. The design procedure is thus conducted to place the dominant poles of the dynamic system at desired locations on the s-plane so that the unstable dynamics, which is the required criterion for energy generation, is achieved. Next, the closed-loop poles are selected based on a desired frequency so that a periodical system is found. Consequently, the design parameters, including mass and spring stiffness for both power and displacer pistons, are obtained. Finally, the engine power is calculated through the proposed control-based analysis and the result is compared to those of the experimental work and the Beale number approach. The outcomes of this work clearly reveal the effectiveness of the control-based design technique of FPSEs compared to the well-known approaches such as Beale number.

scholarly journals Robust Switching Control and Subspace Identification for Flutter of Flexible Wing

2018 ◽  
Vol 2018 ◽  
pp. 1-16 ◽  
Author(s):  
Yizhe Wang ◽  
Zhiwei Xu ◽  
Wei Li
Keyword(s):  
Wind Tunnel ◽  
Lyapunov Function ◽  
Closed Loop ◽  
Pole Placement ◽  
Subspace Identification ◽  
Aeroelastic System ◽  
Common Lyapunov Function ◽  
Flexible Wing ◽  
Arbitrary Switching ◽  
Wide Range

Active flutter suppression and subspace identification for a flexible wing model using micro fiber composite actuator were experimentally studied in a low speed wind tunnel. NACA0006 thin airfoil model was used for the experimental object to verify the performance of identification algorithm and designed controller. The equation of the fluid, vibration, and piezoelectric coupled motion was theoretically analyzed and experimentally identified under the open-loop and closed-loop condition by subspace method for controller design. A robust pole placement algorithm in terms of linear matrix inequality that accommodates the model uncertainty caused by identification deviation and flow speed variation was utilized to stabilize the divergent aeroelastic system. For further enlarging the flutter envelope, additional controllers were designed subject to the models beyond the flutter speed. Wind speed was measured online as the decision parameter of switching between the controllers. To ensure the stability of arbitrary switching, Common Lyapunov function method was applied to design the robust pole placement controllers for different models to ensure that the closed-loop system shared a common Lyapunov function. Wind tunnel result showed that the designed controllers could stabilize the time varying aeroelastic system over a wide range under arbitrary switching.

scholarly journals Wide Frequency Band Single-Phase Amplitude and Phase Angle Detection Based on Integral and Derivative Actions

Electronics ◽  
2020 ◽  
Vol 9 (10) ◽  
pp. 1578
Author(s):  
Luccas M. Kunzler ◽  
Luiz A. C. Lopes
Keyword(s):  
Phase Angle ◽  
Single Phase ◽  
Design Procedure ◽  
Active Power Filters ◽  
Power Filters ◽  
Frequency Detection ◽  
Three Phase ◽  
Wide Range ◽  
Phase Amplitude ◽  
Frequency Detector

Numerous applications, such as the synchronization of distributed energy resources to an existing AC grid, the operation of active power filters or the amplification of signals for Power-Hardware-In-The-Loop (PHIL) systems require a few tasks in common. Amplitude, phase angle and frequency detection are crucial for all these applications and many more. Various techniques are presented for three-phase and single-phase applications but only a few of them are able to identify the signals’ attributes for a wide range of frequencies and amplitudes. Single-phase systems are typically burdensome, considering the challenge to create an internal signal, orthogonal with the input, in order to perform the phase angle detection. This matter is even more critical when the amplitude and frequency of the input signal varies in a wide range. This paper presents an Orthogonal Signal Generator (OSG) based on integral and derivative actions. It includes a detailed design procedure and a design example. The performance of a single-phase wide range amplitude and frequency detector based on the discussed OSG is experimentally validated under steady state and dynamic conditions.

scholarly journals DQ-Frame Admittance Estimation of Three-Phase Converters with a Wide Range of Operating Points

2021 ◽  
Author(s):  
Hong Gong ◽  
xiongfei wang ◽  
Dongsheng Yang
Keyword(s):  
Error Estimation ◽  
Closed Loop ◽  
Estimation Method ◽  
Experimental Results ◽  
Multidimensional Interpolation ◽  
Three Phase ◽  
Wide Range ◽  
Linearized Model ◽  
Operating Points ◽  
Error Estimation Method

The <i>dq</i>-frame admittance of closed-loop controlled three-phase converters is a linearized model that is dependent on the operating points of the system. Yet, it is impractical to measure the converter admittance at all operating points. This paper, thus, proposes an approach to estimating the <i>dq</i>-frame admittance of three-phase converters at a wide range of operating points. The method applies multidimensional interpolation to a given set of admittance data, which is measured from the pre-defined operating points. The accuracy of interpolation is then evaluated by using the posterior error estimation method. The number of pre-defined operating points is next adjusted to find a good compromise between the accuracy and efficiency of the approach. Simulations and experimental results verify the effectiveness of the approach.<div><br></div>

Parameter Plane Synthesis and Performance Investigation of a Three-Phase Three-Level Bidirectional Rectifier

2014 ◽  
Vol 15 (6) ◽  
pp. 621-632
Author(s):  
Abdul Hamid Bhat ◽  
Nitin Langer
Keyword(s):  
Closed Loop ◽  
Parameter Plane ◽  
Dynamic State ◽  
Closed Loop Control ◽  
Outer Loop ◽  
Modes Of Operation ◽  
Loop Control ◽  
Voltage Controller ◽  
Three Phase ◽  
And Performance

Abstract In this paper, parameter plane synthesis of a three-phase neutral-point clamped bidirectional rectifier has been performed. The converter involves one outer-loop PI voltage controller and two inner-loop PI current controllers for the closed-loop control. D-partition technique has been employed for the precise design of the voltage controller. An experimental prototype of the converter has been developed, and the experimental investigation of the converter performance in closed loop has been carried out. DSP DS1104 of dSPACE has been used for real-time implementation of the designed controller. The converter gives a very good performance in steady state and dynamic state (for rectification as well as inversion modes of operation) using the designed controller parameters.

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