This paper presents a novel control strategy for a shunt active power filter (SAPF) based on a delta-connected cascaded H-bridge (CHB) topology, aimed at addressing two major challenges: high computational demands of model predictive control (MPC) in multilevel converter systems and the need for reliable compensation of current harmonics and reactive power under dynamic grid conditions. The proposed solution combines a computationally efficient two-step finite control set MPC with a modified instantaneous active–reactive power theory. This approach eliminates the need for weighting factors and enables implementation on low-cost digital signal microcontrollers. The effectiveness of the method is validated experimentally using a 60 kW laboratory prototype with a 200 MHz microcontroller. Results confirm fast dynamic response and significant harmonic reduction.

This paper deals with the design and real-time implementation of a stator turn fault (STF) indicator for online detection of inter-turn short circuit (ITSC) faults in interior permanent magnet synchronous motor (IPMSM) drives. First an evaluation function is defined based on the average value of the spatial saturation harmonic of the machine over an observation window during the online operation of the drive. Then, based on the value of the load current, a correction factor is set for each condition using a look-up table (LUT) to eliminate the dependency of the saturation saliency on the load current. Finally the STF indicator is obtained by dividing the evaluation function by the correction factor for each load condition. A developped hardware FFT processor is used to extract the saturation saliency from the transient inductance of the machine, estimated online by applying an excitation with voltage pulses using the switching of the inverter and then measuring the resulting current slope. The model is embedded into a field programmable gate array (FPGA) and experimental testing is used to evaluate the performance of the proposed STF indicator on a dedicated designed IPMSM with modified stator windings.

An accurate estimation of flux linkage maps is essential for the proper control and modeling of synchronous machines. We propose to use neural networks as the flux linkage model with training procedure respecting the differential equation of the stator current. Moreover, the neural network allows straightforward extension of the number of input variables. We demonstrate this ability to estimate the flux linkage as a function of rotor speed and position modulated by slot harmonics. The proposed approach is demonstrated on real interior permanent magnet synchronous machine data. The results demonstrate a significant improvement in current prediction compared to commonly used methods.

Active filters are necessary devices in the infrastructure of power grid. The active filters improve the quality of electrical energy. This paper describes design of control strategy for active filter, which uses three delta connected 5-level CHB converters. The proposed control strategy is based on finite control set model predictive control. The mathematical model of active filter is derived. The analysis of power grid is based on PQ theory, which calculates instantaneous active and reactive power. The reference values of compensation currents can be set due to PQ theory. The proposed control strategy is verified by simulations where dynamic changes in power grid occurs.

The most common control algorithms for PMSM are based on simplified interpretation of the mathematical model, assuming strictly harmonic signals and linear distribution of the magnetic flux of permanent magnets in the air gap. Nevertheless neglected phenomenons in the mathematical mode leads to deterioration of the torque and overall it may lower the efficiency of the machine. Therefore in order to improve efficiency and torque quality, the aforementioned effects needs to be taken into account, when designing mathematical model, where, stator inductance and magnetic flux of permanent magnets are considered a function of the rotor position. the optimal reference current is no longer projected into d, q coordinated system as a static dc value, which significantly increase the demands on the tuning of cascade structure of PI controllers. An alternative is to use predictive control.In this paper we seek for simple and yet robust control with comparable results as a standard solution based on d, q coordinated system and linear controllers. For this purpose we use simple version of predictive control working with limited control action set (FCS-MPC) with precise model defined in rotating d, q reference frame The resulting algorithm provides high quality torque control performance while taking into account Joule losses in the motor.

Efficiency of an IPMSM motor is influenced by the operating point (OP) of the machine. The optimal operating point can be found by using either direct search methods or model-based methods. Model-based methods are sensitive to parameter uncertainties of the equivalent circuit of the drive. In this paper, the impact of various parameter estimation methods on the motor efficiency is compared. Studied methods are Recursive Least Squares (RLS), frequency domain identification at standstill, and the flux linkage map method. Results are compared to direct search methods, where the efficiency is evaluated using the power consumption measurement and direct measurement of the torque. Comparison is performed on a grid of various setpoints (currents and speed). The RLS is tested in two versions of linearization of the flux: one using only the inductances, the second estimating also their offset. Each method is able to obtain good results for some OPs and bad results for other OPs. Overall, good performance was obtained for direct search, offline identified parameters and flux linkage map and RLS with flux offset. RLS without the flux offset does not yield consistent results which implies significantly lower efficiency.

This paper deals with an experimental injection of harmonics to a stator winding of a nine-phase machine. Different combinations of the harmonic components are applied with the optimal magnitudes calculated by a linear programming to maximize exploitation of a magnetic circuit. The theoretical analysis provides magnetic flux waveforms including distribution in the air gap. Thanks to the prototype of the nine-phase induction machine with in-built test coils wound on the stator tooth and the magnetic pole, the magnetic flux waveforms calculated in the theoretical analysis are verified by those obtained by the experimental measurements.

The main contribution of this paper is design of optimal field oriented (vector) control of a multi-winding permanent magnet synchronous motor. Three variants of vector control structures for the multi-winding synchronous motor are presented in the paper. Each of the presented vector controls uses mutual inductance between particular windings differently. Determining the effect of mutual inductance on vector control is necessary for proper control design of the multi-winding synchronous motor. Furthermore, influence of leakage inductance of the stator winding of this motor is also analyzed. The optimal control is recommended based on the simulation result.

We propose a modification of the recently proposed optimal torque control for time varying parameters. The previous method allows to compute optimal trajectories for synchronous machine considering stator resistance and mutual inductances, however the strategies of transitions between these curves are changed at precomputed speeds. In this contribution, we introduce an algorithm that computes the transition strategies online at the cost of slightly higher computational burden. We also study numerical and DSP implementation issues and show that the computational cost is affordable in conventional DSP. The results are experimentally validated on IPMSM drive of rated power of 4. SkW.

Dual-motor single inverter drives reduce installation space, weight and overall costs. On the other hand, complexity of the control increases significantly, since the condition on each electric motor can vary in a wide range. Today, majority of control algorithms are based on field oriented control. The consequences of parallel connection of induction motors are addressed by prioritizing model of the motors with higher relevance to the control. The control problem becomes even more complicated when the drive is equipped with common sensors measuring phase currents at the inverter output only. Performance of the field oriented control strongly depends on the model with full state, which is not available trough measurement, due to the lack of current sensor for particular motors. We propose to simplify the model of dual motor drive and use it with finite control set model predictive control (FCS-MPC). The steady state solution of the control problem is used to improve the control performance. This is achieved as an additional term in the cost function. The algorithm is designed with respect to maximum simplicity and its properties are tested in simulations as well as in a real experiment on the laboratory prototype of a dual induction motor drive of rated power 2×4.5 kW.

A carrier-based PWM technique proposed for open-end winding drives, which are fed from dual three-phase inverters, is discussed in the paper. The proposed method is based on minimization of infinity norm of a searched vector containing instantaneous modulation values, entering PWM blocks of both inverters. Due to the optimization criterion, the proposed technique is able to generate optimized modulation signals ensuring high utilization of the de-link voltage and achieve comparable performance to classical SVPWM in the normal operation mode. However, besides the normal mode, the method discussed in the paper is designed for attractive fault tolerant operation mode which enables to significantly increase robustness and reliability of an electric drive.

Recently, arc suppression coils are often completed by active systems connected to the secondary winding such as ground fault neutralizers, active earthing and fault localization systems, or systems for current injection. These systems often operate with quantities related to the primary winding. However, direct measurement on the high-voltage side is often not possible. This paper deals with a frequency-independent mathematical modeling of arc suppression coils (Petersen coils) which would enable to simply recalculate quantities from the secondary to the primary side of the coil. Unlike traditional transformers, mathematical modeling is more complicated due to significant difference between high-voltage primary and low-voltage secondary side, high leakage flux, variable coil inductance and variable magnetic circuit topology caused by tunable air gap.

This paper introduces a novel control method for a dual voltage source converter. The proposed method is focused on equal redistribution of power losses among the semiconductor switching devices (IGBTs), which leads to better power utilization of the converter. The main disadvantage of the known control methods for the mentioned converter based on PWM is its unequal distribution of power losses among the IGBTs. Furhermore, the PWM based algorithms are usually fast but the switching sequences have to be strictly defined for defined control requirements. The algorithms based on predictive control fulfill multicriteria control objectives but they are usually computationally demanding, particularly for longer prediction horizons. The proposed method combines advantages of both categories of control approaches as e.g. calculation speed and constant switching frequency of PWM and multicriteria model predictive control with longer prediction horizon. The paper presents theoretical description and power losses distribution model design. Theoretical assumptions are verified by an extensive simulation study.

Finite control set model predictive control (FCS-MPC) has become very popular form of predictive control among the technical society. Thank to its flexibility and well understood and simple structure, it is well suited for control of ac drives. It represents very interesting alternative for conventional control schemes based on cascade structures with PI controllers. The substantial advantage of MPC based approaches, is the ability of control so called MIMO (Multiple Input Multiple Output) systems in a simple way. This paper deals with the design of FCS-MPC for control of multiple induction machine fed from single inverter. Such drive configuration can offer significant cost and installation space reduction. However the complexity of a control design significantly increases. In multi - motor drives, the condition on each electric machine can vary. Typically, this is a case of traction drives, where the load on each electric machine can vary due to the inhomogeneous friction conditions on the railway track. We propose to use FCS-MPC algorithm as a simple alternative to conventional cascade control approaches. In order to verify the performance of proposed algorithm, we have tested the control technique in simulations and experiments on laboratory prototype of rated power 4.5 kW.

Temperature measurement on IGBT modules using voltage-based, direct and infrared methods is presented. The measured temperatures from all three methods are used in determining thermal impedances of IGBT and diodes for air cooled IGBT modules at different air flowrates. Thermal impedances for both active and passive switching elements are measured and the corresponding Foster network is established. The measured temperature and corresponding thermal impedances calculated from measured temperatures using the direct and voltage-based temperature measurement approach are validated using infrared temperature measurements and corresponding thermal impedances calculated from infrared measured temperatures. Finally, thermal impedances calculated from maximum measured IGBT and diode temperatures are compared to those obtained from measured average IGBT and diode temperatures.

Finite control set model predictive control (FCS-MPC) is very effective and simple control approach which has been found suitable for control of various types of power converters. It is a flexible tool because it evaluates an arbitrary cost function which directly influences converter behavior according to particular demand. The limitation of this approach is that efficient calculation is available only for very short prediction horizons. We will show that the input AC part of the CSR is a linear system which can be solved on a much longer horizon using approximation by a LQR solution. In effect, the LQR solution provides a reference for the converter input current which is then added to the cost function of the FCS-MPC algorithm. Comparison of the proposed approach with the conventional FCS-MPC cost is provided in terms of output current tracking, input current THD and average switching frequency. Final results will be introduced by simulation study in MATLAB/Plecs.

A simple adaptive linear current derating strategy for safe operation at low coolant flow rates and optimum operation at temperatures close to the allowed maximum operating junction temperature for electric drivetrain inverters is presented. An inverter junction temperature observer is implemented to calculate the maximum junction temperature which is used as an input to the derating strategy. Results of the proposed strategy are compared with those of the instantaneous derating strategy for different cooling conditions. It is observed that the proposed strategy is robust and eliminates unwanted drivetrain oscillations resulting from abrupt current reduction at low coolant flow rates using instantaneous derating.

This paper presents SVPWM modulation technique with active voltage balancing for three-phase four-level FLC converter. This modulation technique represents the alternative solution for drive applications with multilevel converters. The presented solution is developed for specialized control system based on combination of DSC and FPGA. Presented SVPWM modulator is implemented in FPGA. Solution was tested on low-voltage prototype of four-level flying capacitors converter. The main advantages and disadvantages which were found out during implementation and hardware tests are also described in this paper.

Finite control set model predictive control (FCS-MPC) is very effective and simple control approach which has been suitable for control of various types of power converters. It is a very flexible tool because it evaluates an arbitrary cost function which directly influences converter behavior according to particular demand. For an accurate numerical calculation of the cost function, discretization of state space model is the most accurate approach among the single step calculation methods. Common definition of the current-source rectifier state space model covers only the input ac part of the rectifier whereas the dc part is calculated separately by Euler method. In this paper, definition of full state space model enabling an accurate discretization of all converter variables at once will be introduced, described and compared with a common solution. A behavior of both models will be compared in terms of their performance, robustness and simplicity. Final results will be introduced by simulation study in MATLAB/Plecs.

Energy storage systems (ESS) have large impact on efficiency and reliability of modern electric traction systems. This paper investigates the fuzzy energy management strategy for ESS based on supercapacitors (SC) for human driven trams. Operating the SC on board of a tram brings the following benefits: reduction of peak power demands, decrease of power consumption, improvement of performance and efficiency. Whereas the commonly used ESS Energy management strategies (EMSs) have been dealing without knowledge of vehicle position, the main interest of the presented research is put on the algorithm using the Global Positioning System (GPS). The tram position, located by a GPS module, is used to predict future energy demands and power flows. This information is used in the preparation of the supercapacitor energy level and its power flow control. The optimal ESS power flow with the respect to the tram position is a very complex problem. For this reason, soft computing techniques are used in this paper. The main part of the proposed ESS EMS is the Takagi-Sugeno Fuzzy controller (T-S Fuzzy). The T-S Fuzzy reduces problem dimensionality using the expert knowledge represented by the rules. The output membership functions were finaly optimized by the Differential Evolution (DE).

This paper deals with topology of indirect frequency converter for new mining machine drive fed directly by 6kV ac power grid. The proposed topology is composed of input cascaded H-bridge active rectifier and output cascaded H-bridge inverter. The main attention is paid to control of input cascade H-bridge active rectifier especially to voltage balancing of the individual power cells (H bridge). The proposed control uses conventional PWM with shifted carriers and voltage balancing is solved separately by control algorithm. The paper describes results of the simulation tests for designed low-voltage laboratory prototype of rated power of 10 kW.

Start-stop system of an internal combustion system of a hybrid drive is designed to reduce energy consumption of the drive and reduce the produced emissions. Effectiveness of the start-stop system heavily depends on its ability to correctly predict when the combustion engine will be idle. This makes the problem suitable for model predictive control. In this contribution, we study the case of a hybrid city bus for which we have available recorded profiles of power consumption from repeated drives of the same route. We propose to use these historical data as predictions of the power consumption in the predictive control approach. We show in simulation with recorded data, that the resulting model predictive start-stop system outperforms the rule based approach and yield fuel savings of 5% and operational cost over 2%.

This paper presents a new pulse width modulator dedicated basically for under determined systems. The solution of the under determined problem is performed by minimum 1-inflnity norm solution. One of known under determined system is a four-leg three-phase converter because four reference signals must be created from three control commands. The infinity norm enables to find proper solution to generate corresponding reference signals for the PWM modulator. The designed modulator is implemented with a control system of the four-leg three-phase converter working as an universal supply unit but the proposed modulator is able to operate in arbitrary application with the four-leg converter, generally for arbitrary under-deteremined systems. It is shown in the paper that the known carrier based PWM algorithm represents a subset of modulators utilizing the minimum 1-infinity norm. The theoretical assumptions and the design of the modulator were verified by simulations as well as by experiments on a laboratory prototype of 17 kVA.

A new sensorless control algorithm for surface mounted permanent magnet synchronous machines with direct torque control (DTC) is proposed. The DTC usually operates with a short sampling period, therefore estimation algorithms need to be computationally cheap. Moreover, injection of high-frequency (hf) signals into a given axis can be a challenging task in comparison with a standard vector control with a PWM modulator. In this paper, a modification of the DTC algorithm is proposed to enable hf injections in a separate d-axis in a rotating coordinate system. Demodulation of this signal and sensorless rotor position estimation based on both phase-locked loop and modified extended Kaiman filter are described and evaluated. Verification was performed by both simulations and experiments on a laboratory prototype of a PMSM drive with rated power of 11 kW.

This paper proposes a novel PWM for four-leg voltage-source converter operating as an earth fault current compensator in power grids with unearthed or high-impedance earthed neutral. For proper earth fault compensation, the converter has to draw zero-sequence currents from the three-phase grid. Its control is based on three independent proportional-resonant controllers. The main task of a new modulator is to generate from three outputs coming from the control block four modulation signals entering the PWM. In order to minimize a dc-link voltage of the converter, the least norm method is used to eliminate high difference of amplitudes of the modulation signals.

In high-power applications, current-source rectifiers are still popular due to their simple topology, robustness and nearly sinusoidal grid current. They can be also operated with unity or variable power factor. In this way, the rectifier can serve as a power factor compensator. Beside this, they directly control load current which makes them sufficient for direct supply of DC motor. However, the significant disadvantage of the common CSR topology is that they are not able to change load current direction - they operate only in two quadrants. In this paper, three phase space vector modulated four quadrant active current-source rectifier with DFT based power factor control for dc motor drive is introduced. Developed control algorithm is widely described and its behavior verified by simulation study.

Finite control set model predictive control (FS-MPC) has been shown to be a very effective approach to control of PMSM drives. FS-MPC is a very flexible tool since it can evaluate an arbitrary loss function. However, design of the appropriate loss function for the problem can be a challenge especially when the design input is visible only on the long horizon. An example where this problem becomes apparent is the main propulsion drive of a traction vehicle fed from a dc catenary. Specifically, the catenary voltage is subject to short circuits, fast changes, harmonics and other disturbances which can vary in very wide range. Therefore, the drive is equipped with the trolley-wire input LC filter. The filter is almost undamped by design in order to achieve maximum efficiency and the control strategy needs to secure active damping of the filter to guarantee the drive stability. While it is possible to introduce active damping terms to the loss function, it is hard to predict its properties. In this paper, we consider decomposition of the problem to control of the LC filter and PMSM drive. We show that the resulting controllers can be elegantly combined using Bellman's principle of optimality. The resulting controller is easy to design and its performance is demonstrated in simulation and experiments on 10.7 kW drive.

This paper describes novel adaptive multiplicative general parameter finite impulse response filter with real coefficients (MGP-FIR). The MGP-FIR is adaptive, predictive digital FIR filter for fundamental harmonic estimation of distorted signal with small frequency fluctuations without phase shift (time delay). This property is necessary for high quality control of power converters connected to the AC power line (active source rectifiers, voltage inverters, active power filters etc.) The goal of this paper is to present design and simulation results of different MGP-FIR filters and their behavior represented by frequency responses.

The aim of this paper is an investigation of an extended Kaiman filer (EKF) based on a model in phase coordinates for sensorless control of an interior permanent magnet synchronous motor (IPMSM) with higher harmonics in the motor flux. The challenge for the EKF is to minimize its execution time especially for model in phase coordinates. This is achieved by using state space model of the drive with only two state variables, the rotor speed and the rotor position, which is known as the reduced-order model. This paper describes proposed EKF based estimator, verifies in simulations and experiments, that the EKF with this reduced model has low computational cost and high estimation accuracy. All experiments were carried out on a laboratory prototype of the IPMSM drive with rated power of 4 kW.

This paper describes a control algorithm of a single-phase voltage-source converter with an LCL output filter behaving like a high-quality controlled current source. Designed control algorithm combines model based (feed-forward) control with a feedback direct current control based on resonant controllers. This control method provides precise (low THDi) sinusoidal waveform of required output current. The theoretical conclusions presented in this paper are verified by experiments made on developed laboratory prototype of current source.

The aim of this paper is to study the use of the Extended Kalman filer (EKF) for sensorless control of a permanent magnet synchronous motor (PMSM) drive controlled by direct torque control (DTC). In contrast to the vector control, the DTC allows for better compensation of the dead-time effects, however, it also needs to run with much shorter sampling period. The challenge for the EKF is to minimize its execution time. This is achieved by using state space model of the drive with only two state variables, the rotor speed and the rotor position, which will be known as the reduced model. We show in simulations and experiments, that the EKF with this reduced model has the same performance as the four-dimensional full order model at much lower computational cost. This allows to use the EKF even in DTC with very short sampling time and take full advantage of the dead-time compensation. Due to better reconstruction of the voltage vector, the sensorless DTC is able to operate the drive at lower speed than the vector control with the same estimator. All experiments were carried out on a laboratory prototype of the drive with rated power of 11 kW and 44 poles. Control algorithms using DTC with sampling periods of 30 or 50 μs and vector control with sampling period of 125 μs were compared. The sensorless DTC with the reduced model EKF was found to be equal to DTC with the full model EKF in terms of performace and superior in terms of computational cost. Both sensorless DTC algorithms outperformed the vector control algorithm in accuracy of the estimation especially at low speed.

This paper investigates universal start-up procedure for Flying Capacitor Converter (FLC). Main part of this procedure is pre-charging of the dc-link and flying capacitors. This method is usable for voltage pre-charging in rectifier as well as inverter mode of the multilevel FLC converter. This specific feature is based on use of converter topology and modification of converter switching pulses control. The proposed control improvements are designed to control particularly multilevel converters. The control system is implemented in development platform Multi Level Converter (MLC) interface for a four-level multilevel converter with flying capacitors. Its performance is investigated and evaluated by selected experiments made on a developed converter prototype of the rated power of 30 kVA. This paper also discusses behaviour of converter on occurrence of safe restart and shut-down procedure.

This study proposes a 4-phase voltage-source inverter replacing conventional 3-phase inverters, traditionally used in renewable energy resources, which is able to compensate a fault current, when a single-phase earth fault of the power grid occurs. The investigated method is able to suppress the earth fault current and recover current symmetry in 3-phase insulated or high-impedance grounded power grids. Proposed compensation is made by the 4-phase voltage-source inverter with earthed 4thphase, which can operate, under normal operation condition, equally as a traditionally used 3-phase inverter and supply the ac power grid from the renewable resource. The single-phase earth fault in the power grid is analyzed in the paper. Both simulations and experiments were performed on a mathematical model and on a designed laboratory prototype, respectively, in order to verify the proposed compensation method.

Fan systems, pump systems and compressed air systems consume approximately 60% of total electricity generated worldwide. These systems have very significant cost-effective energy saving potential and/or CO2reduction potential. However, the major barriers preventing to use this potential are i) no simple pattern for general solution - the need of sophisticated individual evaluation of each application for concrete facilities, and ii) the lack of methodology and/or tools that would be able to sufficiently and reliably quantify the real energy saving potential for the most suitable technology both from technological and economical point of view. In this paper, we present the results of research project which is intended to overcome these barriers. It is introduced the developed software tool, methodology and physical background for modeling of high-power industrial fan systems. By specific, we have focused on evaluation and comparison of axial-type fan in the configuration with fixed speed drive and variable pitch flow control and in the configuration with variable speed drive (VSD) and/or flow control which are directly competing technologies for energy-efficient flow control. Comparison was performed on a case study of a fan for cooling towers in thermal and/or nuclear power plants. In addition, we have attached comparisons to conventional flow control methods employing axial type of fans.

Marginalized particle filter is a stochastic filter combining Kalman filters with particle filters. It decomposes the model into linear and nonlinear part and applies the Kalman filter for the former and the particle filter for the latter. In effect, this allows to represent accurately the inherent non-Gaussianity and nonlinearity of the model. This allows estimation of the rotor position of the PMSM drive in the full speed range, including the standstill. The main disadvantage is its high computational cost. In this paper, we present an implementation of the marginalized particle filter in the field programmable logic array (FPGA). The parallel nature of the MPF algorithm allows to use pipelining which yields speedup in the order of magnitude in comparison to the DSP implementation. The sensorless control of the drive is implemented on a board with both DSP and FPGA, where the drive control runs on the DSP and the MPF estimator in the FPGA. Execution time of the estimator is thus negligible in the execution time of the sensorless control. Performance of the resulting sensorless control algorithm is evaluated on a developed drive prototype of rated power of 10.7kW.

Methods of sensorless control of PMSM drives are commonly divided into model-based and high-frequency injection based approaches. Each of these approaches uses a different algorithm for estimation of the rotor position and speed. Typically a Kalman filter is used for the model-based approach and phase-locked loop (PLL) for the hf injection based approach. In this paper, we show that the PLL is a steady state solution of the Kalman filter for a special state space model. Since this model has a commonly used state equations, we can easily combine the observation equations from the model-based approach with those from the hf injections. Several possibilities of combination are described and tested in the paper.We illustrate properties of these algorithms on experimental data in sensored mode. Sensorless control strategy based on the presented models is demonstrated on a laboratory prototype of surface mounted permanent magnet synchronous motor (PMSM) drive of rated power of 10.7kW.

This paper presents a novel estimation approach to sensorless control of wound rotor synchronous motor drives. The proposed rotor position estimation strategy is motivated by principle function of a resolver and utilizes design similarity between the controlled motor and the resolver based rotor position sensor. The rotor circuit is fed by controlled three-phase bridge rectifier which produces an ac component of frequency of 300Hz in the rotor excitation (flux) current. This ac component of rotor excitation current can be understood like an injection signal. Its response on the stator is evaluated by simplified Kalman filter which estimates the rotor position. This paper describes physical principle and functionality of the proposed sensorless rotor position estimation technique and verifies the theoretical foundations by simulation and experimental results made on developed drive prototype of rated power of 10kW.

In high-power traction applications, low distortion power factor (DPF) is generally desirable under all conditions because although the higher harmonic currents cannot apply active power to loads, they cause higher losses in the transmission line and can disturb track circuits. Operation of single-phase current-source active rectifier (ACSR) under distorted catenary voltage conditions causes distortion of catenary current in terms of high THDi values which from the above reason should be suppressed. In this paper, three approaches in DPF control will be introduced, compared and evaluated from the quality of compensation, stability of operation and complexity point of view. Theoretical expectations of considered compensative strategies and their behavior have been verified by both simulations and large experimental study made on developed small-scale prototype of ACSR of rated power of 7kVA.

Fan systems, pumping systems and compressed air systems consume approximately 60% of total electricity generated worldwide. At the same time, these systems have very significant cost-effective energy saving potential. Nevertheless, the major barriers to effectively and widely apply the generally known recommendations are i) the need of individual evaluation of each application for concrete facilities ii) the lack of methodology and/or tools that would be able to sufficiently and reliably quantify the real energy saving potential for the most suitable technology both from technological and economical point of view. In this paper, we present the results of the research project which is intended to overcome these barriers. By specific, we present the developed software tool, methodology and physical background of modeling with the emphasis on comparison of conventional flow control methods to variable speed drives (VSDs). Case study results are also included.

Marginalized particle filter is a stochastic filter combining Kalman filters with particle filters. It decomposes the model into linear and nonlinear part and applies the Kalman filter for the former and the particle filter for the latter. Its application in sensorless control of permanent magnet synchronous motor (PMSM) drives is based on separate treatment of the state variables: the rotor position is represented by a set of samples (particles), and the rotor speed is estimated by the Kalman filters associated with each sample. In effect, this allows to represent accurately the inherent non-Gaussianity and nonlinearity of the model. We show that the resulting filter is capable to estimate the rotor position in the full speed range, including the standstill. Analysis of the filter performance is presented on open-loop off-line analysis of data recorded on a drive prototype. Execution time of optimized implementation of the algorithm for six particles in DSP is comparable to that of the Extended Kalman filter for full state-space model. Closed-loop performance of the filter (a sensorless drive control) is evaluated on developed drive prototype of rated power of 10.7kW.

This paper describes three implementation alternatives of a multiplicative general parameter finite impulse response filter (MGP-FIR) used as a precise current reference generator for shunt-type active power filters. Compared to the traditional techniques that use fixed digital or analogue filters, the MGP-FIR is an adaptive and predictive algorithm for tracking typical frequency variations and thus avoiding the harmful phase shift of the fundamental sinusoid. This characteristic is essential for maximizing the harmonics reduction ability of the active power filter. The fixed subfilters of the MGP-FIR are pre-optimized by the use of a genetic algorithm. The harmonics reduction ability was verified by extensive simulations. Moreover, a laboratory prototype was developed and experimentally tested under typical non-linear loads. Compared to the previously presented articles on MGP-FIR-based current reference generators, this is the first time when real-valued or fixed-point coefficients are used with the MGP-FIR. In addition, we also improved the originally proposed amplitude detector. The results are compared with those presented earlier.

The paper deals with continuous blood pressure measurement. In the intensive care, there is a need to monitor the blood pressure waveform in the real time. It is realised directly by catheters. Also indirect unloading continuous plethysmografic technique of blood pressure waveform monitoring can be used. Even some instrument have been developed as described bellow, there does not exist any one widely used in medical care. The insufficient accuracy and stability for clinical purposes require the analysis of this non-linear system and the adaptive control description of the blood pressure waveform monitoring technique. New monitoring device has been designed Our aim is to design simple, low-cost and enough stable monitoring system that can be extended in medical praxis.