Introduction Energy Factor (EF) and Sub-Sequential Parameters Basic Mathematics of Digital Control Systems Mathematical Modeling of Digital Power Electronisc Digitally Controlled AC/DC Rectifiers Digitally Controlled DC/AC Inverters Digitally Controlled DC/DC Converters Digitally Controlled AC/AC Converters Open-Loop Control for Digital Power Electronics Closed-Loop Control for Digital Power Electronisc Energy Factor Application in AC and DC Motor Drives Applications in Other Branches of Power Electronics

Digital Power Electronics and Applications

40 years of sensor fusion for orientation tracking via magnetic and inertial measurement units: Methods, lessons learned, and future challenges

Attitude estimation is one of the core frame- works used for navigating an unmanned aerial vehicle from one place to the other. This paper presents an Euler-based non-linear complementary filter (CF) whose gain parameters are obtained using particle swarm optimization (PSO) technique. It relieves the user from feeding the KP and KI parameters manually and adjust these parameters automatically when the error between the attitude measured from accelerometer and the CF increases above a particular threshold. The measurement unit for this research consists of micro-electro-mechanical-systems (MEMS) based low cost tri-axial rate gyros, accelerometers and magnetometers, without resorting to global positioning system (GPS) data. The efficiency of the CF is experimentally investigated with the help of reference attitude and the raw sensor data obtained from commercial inertial measurement unit (IMU). Simulation results based on the test data show that the proposed PSO aided non-linear complementary filter (PNCF) can automatically obtain the required gain parameters and exhibits promising performance for attitude estimation.

PSO Aided Adaptive Complementary Filter for Attitude Estimation

In the paper the design of an aircraft motion controller based on the Dynamic Contraction Method is presented The control task is formulated as a tracking problem for Euler angles, where the desired decoupled output transients are accomplished under assumption of high-level, high-frequency sensor noise and incomplete information about varying parameters of the system and external disturbances The resulting controller has a simple form of a combination of a low-order linear dynamical system and a matrix whose entries depend nonlinearly on certain measurable flight variables

Robust Quasi NID Aircraft 3D Flight Control Under Sensor Noise

This paper presents a passivity-based control (PBC) design methodology for three-phase voltage source inverters (VSI) for uninterruptable power supply (UPS) systems where reduced harmonic distortions for the nonlinear load, reduced output voltage overshoot, and a restricted settling time are required. The output filter design and modification for efficient control and existing challenges with the assignment of scaling coefficients of the output voltage, load, and inductor currents are addressed and analyzed. Notably, special attention is given to the modulator saturation issue through implementing an accurate converter model. Applications of the two versions of PBC in three-phase voltage source inverters using stationary αβ and rotating dq frames for a constant frequency of the output voltage are presented. Furthermore, the influence of the PBC parameters on the power converter performance is investigated. A comparative simulation and the experimental results validate the effectiveness of the presented passivity-based control design methodology.

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Passivity-Based Control Design Methodology for UPS Systems

Coupled tanks systems play an important role in teaching of control theory. Although due to the existence of two independent storages, making them a second order system, it has been shown that one time constant is at least 6 time greater than the other. In normal operation conditions this ratio is about 10–20. Therefore, special attention is necessary to explain their properties.

On significance of second-order dynamics for coupled tanks systems

A detailed analysis of PID level control in the second tank of the cascade of two tanks is performed with respect to both, load disturbance attenuation and set-point change. Approximate formulas for extrema of time responses and for certain performance indices are derived, giving guidelines for controller settings. A simple method of choosing controller parameters is proposed that bases on time scale separation. For a reasonable transfer from one operating point to another, under control signal limitations, command signal generators with a feedforward from the reference are proposed and the effect of anti-windup controller augmentation is examined.

High performance PID control of a cascade tanks system as an example for control teaching

The huge influence of the sampling rate on the performance of the digital PID control of a voltage source inverter (VSI) is revealed. It is shown that an appropriately chosen continuous-time model of a digital controller with the PWM power converter behaves like the actual discrete-time system, which allows for a simple controller analysis and design. The variable structure nature of the inverter with both the RC rectifier and an abruptly changing resistive load with two modes of operation within the sampling period is directly taken into account. Two simulation models, a discrete-time PWM and a continuous-time, of an inverter are presented, which are used to tune the PID controller and to evaluate the control performance. The behavior of the system in both modes is explained on the basis of the root loci and frequency characteristics. The results obtained for three sampling rates: 12.8, 25.6, and 51.2 kHz, are presented and compared with an actual VSI experiment. A comparison with other results obtained for this VSI shows that properly tuned PID control outperforms the more sophisticated solutions based on the coefficient diagram method (CDM) and the passivity based control (PBC).

Sampling Rate and Performance of DC/AC Inverters with Digital PID Control—A Case Study

The paper presents modeling and simulation of DC/AC inverters with PID controllers designed so as to induce time-scale separation between fast mode of controller and slow mode of the output signal. The sampled data PWM system is modeled using its quasi-continuous time representation. SIMULINK models are used to verify approximations used. The results are verified on a real inverter.

Design, Modeling and Simulation of PID Control for DC/AC Inverters

Dynamic properties of a coupled tanks apparatus are analyzed in the context of control teaching. The main issue detected is that although it is a second order system, its dynamics are very similar to that of a first order one. The paper highlights the problems which should be discussed when the coupled tanks experiment is used for control teaching.

Rafal Grygiel

Papers

On significance of second-order dynamics for coupled tanks systems

High performance PID control of a cascade tanks system as an example for control teaching

Sampling Rate and Performance of DC/AC Inverters with Digital PID Control—A Case Study

Design, Modeling and Simulation of PID Control for DC/AC Inverters

Remarks on the coupled tanks apparatus as a control teaching tool