This book, written by two major figures in adaptive control, provides a wealth of material for researchers, practitioners, and students. While some researchers in adaptive control may note the absence of a particular topic, the book‘s scope represents a high-gain instrument. It can be used by designers of control systems to enhance their work through the information on many new theoretical developments, and can be used by mathematical control theory specialists to adapt their research to practical needs. The book is strongly recommended to anyone interested in adaptive control.

Adaptive Control

A new era of power electronics was created with the invention of the thyristor in 1957. Since then, the evolution of modern power electronics has witnessed its full potential and is quickly expanding in the applications of generation, transmission, distribution, and end-user consumption of electrical power. The performance of power electronic systems, especially in terms of efficiency and power density, has been continuously improved by the intensive research and advancements in circuit topologies, control schemes, semiconductors, passive components, digital signal processors, and system integration technologies.

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Toward Reliable Power Electronics: Challenges, Design Tools, and Opportunities

The aim of this paper is to review the state-of-the-art of Field Programmable Gate Array (FPGA) technologies and their contribution to industrial control applications. Authors start by addressing various research fields which can exploit the advantages of FPGAs. The features of these devices are then presented, followed by their corresponding design tools. To illustrate the benefits of using FPGAs in the case of complex control applications, a sensorless motor controller has been treated. This controller is based on the Extended Kalman Filter. Its development has been made according to a dedicated design methodology, which is also discussed. The use of FPGAs to implement artificial intelligence-based industrial controllers is then briefly reviewed. The final section presents two short case studies of Neural Network control systems designs targeting FPGAs.

https://hal-centralesupelec.archives-ouvertes.fr/hal-01337007/document

FPGAs in Industrial Control Applications

The letter presents an exact small-signal discrete-time model for digitally controlled pulsewidth modulated (PWM) dc-dc converters operating in constant frequency continuous conduction mode (CCM) with a single effective A/D sampling instant per switching period. The model, which is based on well-known approaches to discrete-time modeling and the standard Z-transform, takes into account sampling, modulator effects and delays in the control loop, and is well suited for direct digital design of digital compensators. The letter presents general results valid for any CCM converter with leading or trailing edge PWM. Specific examples, including approximate closed-form expressions for control-to-output transfer functions are given for buck and boost converters. The model is verified in simulation using an independent system identification approach.

Small-Signal Discrete-Time Modeling of Digitally Controlled PWM Converters

An integrated digital controller for dc-dc switch-mode power supplies (SMPS) used in portable applications is introduced. The controller has very low power consumption, fast dynamic response, and can operate at programmable constant switching frequencies exceeding 10 MHz. To achieve these characteristics, three novel functional blocks, a digital pulse-width modulator based on second-order sigma-delta concept (Sigma-Delta DPWM), dual-clocking mode compensator, and nonlinear analog-to-digital converter are combined. In steady state, to minimize power consumption, the controller is clocked at a frequency lower than SMPS switching frequency. During transients the clock rate is increased to the switching frequency improving transient response. The controller integrated circuit (IC) is fabricated in a standard 0.18-mum process and tested with a 750-mW buck converter prototype. Experimental results show the controller current consumption of 55 muA/MHz and verify closed-loop operation at programmable switching frequencies up to 12.3 MHz. Simulation results indicating that this architecture can potentially support operation at switching frequencies beyond 100 MHz are also presented.

/pdf/multibit-sigma-delta-pwm-digital-controller-ic-for-dc-dc-5eehiu6e9v.pdf

Multibit $\Sigma$ – $\Delta$ PWM Digital Controller IC for DC–DC Converters Operating at Switching Frequencies Beyond 10 MHz

For digitally controlled switching power converters, on-line system identification can be used to assess the system dynamic responses and stability margins. This paper presents a modified correlation method for system identification of power converters with digital control. By injecting a multiperiod pseudo random binary signal (PRBS) to the control input of a power converter, the system frequency response can be derived by cross-correlation of the input signal and the sensed output signal. Compared to the conventional cross-correlation method, averaging the cross-correlation over multiple periods of the injected PRBS can significantly improve the identification results in the presence of PRBS-induced artifacts, switching and quantization noises. An experimental digitally controlled forward converter with an FPGA-based controller is used to demonstrate accurate and effective identification of the converter control-to-output response.

System identification of power converters with digital control through cross-correlation methods

This paper presents an approach to automated digital controller design for switching power converters. Starting from an experimentally identified frequency response, parameters of the converter transfer function are estimated using a least logarithmic squares method. A direct digital design method then yields a compensator that results in the desired closed loop response. Application of the method is illustrated on an experimental digitally controlled 90 W DC-DC forward converter

Automated Digital Controller Design for Switching Converters

A practical approach for on-line identification of power converter dynamic responses using low-cost digital hardware is presented. The development provides a first step towards adaptive power delivery in electronic systems and can be used for simple off-line controller design. A hardware efficient algorithm is derived and verified with experimental results using a 90 W forward converter with an FPGA-based digital controller

Practical on-line identification of power converter dynamic responses

A modified cross-correlation method for system identification of power converters with digital control

This paper demonstrates the feasibility of detecting an onset of instability by monitoring the pattern of the output voltage error signal, and adaptively changing the compensator parameters in a digitally controlled switched-mode power supply. The techniques are verified on an experimental 90 W, 50 V-to-15 V forward converter where an abrupt change in operating conditions that leads to instability is emulated by removing the input filter damping. It is shown that the system can regain stability and return to regulation. The proposed techniques have potential applications in decentralized active stability control of power management and distribution systems typical for aerospace applications

B. Miao

Papers

System identification of power converters with digital control through cross-correlation methods

Automated Digital Controller Design for Switching Converters

Practical on-line identification of power converter dynamic responses

A modified cross-correlation method for system identification of power converters with digital control

Detection of instability and adaptive compensation of digitally controlled switched-mode power supplies