The main focus of this paper is to propose high quality, low complexity predictive torque control for IPMSM, which typically exhibits a high level of non-uniformity. Particular solution to this problem may results in high complexity flux mapping, which negatively impacts complexity of the control algorithm. To achieve sufficient accuracy while complexity of the control remain acceptable, we propose to design accurate model which is approximated in a piece-wise manner addressing the most dominant effects on the drive behavior. This is done by state dependent terms using data collected by prior commissioning procedures and verified by FEM simulation. Resulting mathematical model is very simple to implement. We use predictive control with finite control set and cost function following the idea of direct torque control. The proposed controller has been experimentally tested and compared to the controller with conventional mathematical model to demonstrate the effect of the model accuracy on control performance.

There can be seen rising trend of the multilevel converters in battery storage systems, specifically converters with cascaded H-bridges. Use of the battery distributed through converter has many advantages. It lowers requirements on the battery management system and improves reliability of the BESS in cause of the faulty module. In this topology part of the battery balancing is provided by the converter itself. In this paper, it is compared the choice of delta versus star connected three phase converter. This choice influences mainly phase-to-phase balancing of the converter.

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.

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.

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.

High power ultra-fast charging station for public transport systems becomes integral part of an urban power grid. In some cases the station has to be supplied by existing power grid 3×400VAC. This paper describes charging station based on a cost-effective topology with an output power over 300kW intended for charging electrical busses. Main part is focused on control algorithm proposal. Performance is verified by a simulation of steady-state and transient conditions.

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.

This paper describes the sliding discrete Fourier transform algorithm (SDFT) for parallel admittance estimation. The SDFT is a popular algorithm for continual single-point or several-point spectral analyzes of discrete time signals. The main drawback of the SDFT is a numerical stability issue. The paper describes the algorithm of SDFT with guaranteed numerical stability by parallel spectra computation. Furthermore, the paper presents the application of SDFT for continual parameter identification of grid to ground admittance of ac power distribution network. The grid admittance is analyzed by voltage response on injected current into auxiliary winding of the Petersen coil. The spectral analyses of injected current and voltage response are used for Petersen coil tuning. The current is injected by H-bridge voltage source inverter.

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.

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.

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.

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.