Digital Control Board Research Articles

Integrated, digitally controlled, 64-element SiGe on multilayer organic X-band phased-array receiver antenna for snow measurements

To the author's knowledge, this work represents the first demonstration of an X-band integrated 64-element active phased-array receiver using SiGe and organic multilayer (LCP + Duroid) technologies. The design and measurement of the antenna, SiGe T/R module, and integrated subarray antenna were presented. In addition, the design of the FPGA digital control board was also presented, which enabled beam steering and control of the phase shifters. This receive subarray was designed for use in SCLP applications and meets performance, cost, and size requirements for use with compact platforms, such as UAVs.

Speed Sensorless Induction Motor Drive With Predictive Current Controller

Today, speed sensorless modes of operation are becoming standard solutions in the area of electric drives. This paper presents a speed sensorless control system of an induction motor with a predictive current controller. A closed-loop estimation system with robustness against motor parameter variation is used for the control approach. The proposed algorithm has been implemented using field-programmable gate arrays (FPGAs) and a floating-point digital signal processor (DSP). Both computational elements have been integrated on a single board SH65L type and interfaced to the power electronic converter, and the use of proper FPGA and DSP optimizes the cost and computational properties. The novelty of the presented solution is the integration of a simple observer for both speed/flux and current control purposes, and the obtained results have been improved in comparison to the previous works. An overview of the test bench consisting of a digital control board, as well as computational algorithms and system benchmarks, is presented. All the tests were performed experimentally for 5.5-kW electric drives.

Frequency Adaptive Least-Squares-Kalman Technique for Real-Time Voltage Envelope and Flicker Estimation

This paper presents real-time implementation of a new frequency adaptive least-squares-Kalman (LSK) technique to monitor voltage flicker and fluctuations in power system. The proposed method is based on a two-level mathematical model of a voltage waveform. A simple low computation frequency tracking method is also introduced. The least-squares (LS) optimization algorithm extracts the fundamental frequency component of the voltage and updates its internal model based on the estimated frequency of the voltage waveform. The Kalman filter, which works in combination with the LS algorithm, is developed to predict the instantaneous voltage flicker level. The proposed method is robust and adaptive and is evaluated experimentally through real-time implementation with a widely available digital control board.

Gain Scheduling Adaptive Proportional-integral Controller for a Field-oriented Control of Hybrid Stepper Motor Drives

This article presents a gain-scheduling adaptive proportional-integral speed controller for field-oriented control of hybrid stepper motor drives. The proportional-integral gains are designed to be a function of the speed error and are allowed to vary within a pre-determined range. This, therefore, eliminates the problems suffered by the conventional proportional-integral controller. The performance of the proposed gain-scheduled proportional-integral controller with field-oriented control is simulated and compared with that of the conventional fixed proportional-integral controller under starting, speed reversal, repetitive operation, and parameter variations, as well as load disturbances. The experimental system of the hybrid stepper motor drive is implemented using a digital signal processor DS1102 control board (Texas Instruments, dSPACE GmbH, Germany) to examine and evaluate the performance criterion of the proposed controller under different operating conditions. Simulation and experimental results show good improvement in transient as well as steady-state responses of the proposed controller over the conventional fixed proportional-integral one. Moreover, field-oriented control of a hybrid stepper motor modifies the dynamic performance and current distortion rather than the stepping mode of the open-loop control system.

Implementation of a New Linear Control Technique Based on Experimentally Validated Small-Signal Model of Three-Phase Three-Level Boost-Type Vienna Rectifier

In this paper, the design and implementation of a new multiple-input-multiple-output linear control technique based on a theoretically established and experimentally validated small- signal model for the three-phase three-level boost-type ac/dc Vienna converter are presented. Averaging and local linearization techniques are used to derive the dynamic model expressed in the dqo reference frame. The resulted transfer functions are discretized for the sake of a digital controller design. Multiple-loop control strategy is adopted and consists of inner current feedback loops, which are based on the straightforward looping technique that neglects interactions between the dq components of control inputs and currents, respectively, and of an outer voltage loop, which is designed to ensure dc voltage regulation by adjusting the magnitude of the references for the inner current loops. The output dc voltage unbalance is also controlled in the inner loops. The proposed modeling and control approaches are first simulated and then validated on a 1.5-kW laboratory prototype supported by the DS 1104 digital real-time controller board of dSPACE. The obtained results prove the accuracy of the proposed new small-signal model and, therefore, its reliability for dynamic analysis and control design purposes. It is also proved that a judicious choice of controller parameters, as well as an adequate rating of boost inductors, allows one to meet the IEEE standard requirements in terms of ac line-current total harmonic distortion and power factor. The efficiency of the proposed control technique is maintained in case of disturbances occurring on both source and load sides.

Vibration reduction of curved panels by active modal control

Active vibration control using modal controllers has been successfully implemented on simple structures such as beams and plates. Since the dynamic behavior of a variety of mechanical structures can be expressed in terms of modal parameters, the application of modal control concepts can be extended to structures with more complex geometries. For such structures, the evaluation of modal parameters from numerical calculations of local modes is complicated because the results strongly depend on proper boundary conditions of the truncated structure. Therefore, the modal data is identified using experimental modal analysis. The transformation of the experimentally measured mode shapes into closed-form analytical formulations and the extraction of modal input and output factors for sensors and actuators are used to connect experimental modal analysis with modal control theory. The implementation of the input and output factors in a modal state space formulation results in a modal filter for the point sensor array and a retransformation filter for the segmented actuator patches. In this study, PVDF film is used for sensors and actuators. The modal controller is implemented on a digital controller board, and experimental tests with the floor panel and center panel of a car body are carried out to validate the proposed concept.

A DSP-Based Active Disturbance Rejection Control Design for a 1-kW H-Bridge DC–DC Power Converter

This paper presents the design and implementation of an advanced digital controller for a 1-kW H-bridge dc-dc power converter. A new control algorithm based on the active disturbance rejection concept is developed to cope with the highly nonlinear dynamics of the converter and the disturbances. An experimental digital control system is used to implement the new control strategy. It consists of a digital control board based on the TMS320C6711 digital signal processor chip, an analogy I/O board, and a complex programmable logic device pulsewidth-modulation generation board. Using a newly developed bandwidth-parametrization technique, an autotuning method based on noise quantification is also developed and tested. Experimental results show the advantages and flexibilities of the new control method for the H-bridge dc-dc power converter.

Full-digital control boards for IGBT full-bridge switching converters

In the field of thermonuclear fusion research, the need to implement coil systems supplied to perform local controls of magnetic fluxes or to generate rotating magnetic fields has grown in the past few years. Tens of coils, each one able to produce up to tens of millitesla on a surface of hundreds of square centimeters, have to be independently fed by converters rated for powers of hundreds of kilowatts and bandwidth in the order of hundreds of hertz. The approach for the design of the converter system, described in this article, involving 22 insulated-gate bipolar transistors (IGBTs) full-bridges, was a semi-custom solution. It is based on the utilization of a well-tested and optimized industrial product for the power section, including the IGBTs driving signal board and the development of a new digital control board. This choice is also in line with the present trend in power-electronic technology that suggests using as much standardized subassemblies as possible and customizing them for different applications.

The power supply of the radial field control system at the RFX equatorial gap

This paper deals with the design of a full-digital controlled, advanced power supply system, which has been designed to control the radial field at the 22 portholes of the shell outer equatorial gap of the RFX machine. The paper, after a brief description of the system, focuses on the structure of the new real-time control of the 22 switching converters, on the main features of the digital control board and on the interface with the RFX real-time central controller.

ACTIVE VIBRATION CONTROL OF A CAR BODY BASED ON EXPERIMENTALLY EVALUATED MODAL PARAMETERS

Active vibration control has been successfully tested for structures with simple geometry, such as beams and plates, by using modal controllers. Since the dynamical behaviour of a variety of mechanical structures can be expressed in terms of modal parameters, the application of modal control concepts can be extended to structures with more complex geometries. For such structures the evaluation of modal parameters from numerical calculations of local modes is complicated because the results strongly depend on proper boundary conditions of the truncated structure. Therefore, the modal data are identified by an experimental modal analysis. The transformation of the experimentally evaluated mode shapes into a closed analytical formulation and the extraction of modal input and output factors for sensors and actuators connect experimental modal analysis and modal control theory. The implementation of the input and output factors into a modal state-space formulation results in a modal filter for the point sensor array and a retransformation filter for the segmented actuator patches. In this study, PVDF foil is used for sensors and actuators. The modal controller is implemented on a digital controller board and experimental tests with the floor panel and centre panel of a car body are carried out to validate the proposed concept.