Metastatic pulmonary calcification as a rare complication of end-stage renal disease with coexistence of pulmonary metastases from renal cell carcinoma : case report and literature review

Purpose: We present a case of metastatic pulmonary calcification (MCP) in an asymptomatic patient with chronic kidney disease after renal transplantation and nephrectomy due to renal cancer. Chest computed tomography (CT) revealed bilateral, diffuse, centrilobular ground-glass opacities and heterogeneous, high-density areas distributed throughout the lungs, predominantly in the upper and middle lobes. Unusually, in our patient the metastatic calcification coexisted with pulmonary metastases from renal cell carcinoma associated with end-stage renal disease. To our knowledge, such coexistence has not been previously described. Case report: CT, particularly high-resolution chest computed tomography (HRCT), plays an important role in detection and follow-up of MPC findings, which include ground-glass opacities and partially calcified nodules or consolidations, predominantly in the upper lung zones. Correct diagnosis is important because misdiagnosis may lead to improper or unnecessary treatment and/or procedures. Conclusions: MPC is a rare condition that results from calcium deposition in the normal pulmonary parenchyma. MPC commonly occurs in patients with end-stage chronic kidney disease due to abnormalities in calcium and phosphate metabolism. It is worth pointing out that despite the fact that the condition is called metastatic, it is a relatively benign lung disease with a generally good long-term prognosis

Speed control of asynchronous motor in system with output LC filter

W układach napędowych z tranzystorowymi falownikami napięcia występują niekorzystne zjawiska wynikające z dużych stromości napięć zasilających silnik. Aby ich uniknąć między falownik a silnik włącza się filtr bierny wygładzający przebiegi napięć i prądów silnika. Włączenie takiego filtru sinusoidalnego powoduje zmianę struktury układu i powoduje konieczność modyfikacji układu sterowania silnika i estymatorów zmiennych stanu układu. W niniejszym referacie przedstawiono układ napędowy w sterowaniu którego uwzględniono filtr sinusoidalny.In the electric drives with voltage inverters appears disadvantageous phenomena come from high du/dt in motor supply voltage. To prevent that phenomena the passive filter is introduced between motor and inverter. Filter assure smoothed voltages and current in the electric motor. When the filter is used the structure of the system is changed so the control and estimation structure should be changed also. In the paper the modified electric drive with output LC filter is presented

Zero current component in the wind power plant with permanent magnet synchronous generator

In the rotating electrical machines working with transistorized converters common mode (CM) voltage current appears. The reasons of the CM voltage appearing are inner properties of the transistors control algorithms. When the CM voltage exists the CM current can flow through parasitic capacitance of the electrical machines and converters. Part of that current flows through motor bearing and strongly decreases bearing life. Example of power electronics drive is wind generator system. In the wind generator system two converters are used: machine inverter and grid inverter. In the presented system the permanent magnet synchronous generator (PMSG) was used. For PMSG efficient control the position of the rotor should be known. In the realized drive to eliminate position sensors the sensorless control method was implemented. During realization of the sensorless control the problem with the measurements of the machine voltage appeared. The measured voltage was strongly disturbed by flow of the common mode current. To solve that problem the path the high impedance for CM path was inserted. Two solutions: zero component choke and three-phase transformer applied between the generator drive system and the electric grid were tested. In the paper the CM voltage theory is presented. The results of the experimental investigations are presented

Wykrywanie i kompensacja składowej harmonicznej momentu w napędach z silnikiem indukcyjnym i przekładnią

In many solutions of drives, the torque transmission systems are used for torque converting from the motor shaft to the load. Properties of torque transmission system are a reason of mechanical vibration occurring in drive system. Analysis of drive vibration, usually measured by the accelerometer, makes it possible to create diagnostic system for detection of mechanical faults of drive. In many applications, an introducing of vibrations to drive system is undesirable. Mechanical vibrations of drive can be reduced by generation of appropriate torque components in electric machine. Proper compensation of mechanical vibration requires information about amplitudes and frequencies of vibration harmonics. In drive system with gear, the reduction of mechanical vibration and early detection of gear damages require information about mutual position of toothed wheel and the torque transmitted by gear. Analysis of state variables of induction motor makes it possible to indicate the instants of toothed wheels meshing. It makes it possible to eliminate both: vibration and optical sensors in systems of detection of gear damages and compensation of mechanical vibration. In this paper a method of sensorless detection of torque ripples, caused by gear transmission, is proposed. Presented method can be use in systems for early detection of gear damages and for active compensation of mechanical vibration. The results of simulation and experimental researches on proposed detection and compensation method are presented in the paper. The experiments were provided for a drive with 10kW induction motor with gear and for a high-speed train drive with gear and 1.2MW asynchronous motor

Wind power station witch double fed induction generator

W referacie przedstawiono propozycję układu sterowania elektrowni wiatrowej pracującej w systemie elektroenergetycznym. Syntezę układu regulacji przeprowadzono bazując na multiskalarnym modelu maszyny indukcyjnej dwustronnie zasilanej (MDZ). Optymalne przetwarzanie energii wiatru, odpowiadające ekstremalnej regulacji mocy czynnej turbiny, zrealizowano na podstawie charakterystyk statycznych. Przedstawiono wyniki badań symulacyjnych.This paper propose a control strategy of double fed induction machine working as generator in wind power generating system, connected to the network. The synthesis of the control system is based on a multiscalar model of DFM. A controller, witch maximizes the power output of turbine is also described

MS analysis of polypeptides produced by hydrolysis of collagen: from technology to interesting discovery?

Zaobserwowano w trakcie analizy MS produktu pozyskiwanego w technologii hydrolizy kolagenu, że cząsteczki otrzymywanych polipeptydów jonizują się ok. 50-krotnie (przy zastosowaniu technik elektrosprej i fotojonizacji pod ciśnieniem atmosferycznym: MS-ESI i MS-APPI). Pozwoliło to opracować szybką i dogodną metodę analizy na potrzeby tej technologii. W artykule podjęto próbę dyskusji nad przyczynami i zaskakującą powtarzalnością obserwowanej multi-jonizacji.MS analysis of polypeptides, produced during industrial collagen hydrolysis, allowed to observe that multiple ionization of product molecules is approximately equal ca 50+ (using electrospray and atmospheric pressure photoionization techniques: MS-ESI and MS-APPI). This observation brings fast and convenient analytical method for the above technology. In this article, the reasons of the observed unexpected multiionization (and its repeatability) is discussed

Stability of inverter fed induction motor

W artykule zamieszczono wstępne wyniki badań analizy stabilności silnika indukcyjnego zasilanego z falownika napięcia. Przedstawiono model matematyczny silnika indukcyjnego oraz określono warunki pracy układu przyjmując założenia dla wyznaczenia równań opisujących pracę układu napędowego w stanie ustalonym. Określono transmitancję silnika indukcyjnego w celu wyznaczenia zakresu jego stabilnej pracy. Wykazano możliwość wystąpienia niestabilnej pracy układu z silnikiem indukcyjnym zasilanym z falownika napięcia.The preliminary results of stability analysis of control system for inverter fed induction motor are presented. The mathematical model of induction motor is presented as well as working conditions of the system are defined with steady state assumption for electric drive equations. The transmittance of induction motor was determined to specify the stability range. Possibility of instability of control system for inverter fed induction motor is proofed

Sensorless low speed PMSM control with cogging torque compensation

W pracy przedstawiono propozycję rozwiązania problemu bezczujnikowego sterowania wolnoobrotową maszyną synchroniczną z magnesami trwałymi PMSM. Przedstawiono silnik PMSM, który zastosowano w stanowisku badawczym. Omówiono problem występowania tętnień momentu napędowego wynikający głównie ze znacznego momentu zaczepowego. Pokazano rozwiązanie kompensujące tętnienia momentu napędowego w silniku PMSM. Przygotowano procedurę startową układu regulacji prędkości pozwalającą na uruchomienie napędu bez czujników prędkości i położenia. Do sterowania silnikiem użyto metodę sterowania polowo zorientowanego z regulatorami PI prądów stojana w osiach dq. Przedstawiono zależności nowej, prostszej wersji obserwatora stanu. Pokazano wyniki eksperymentów potwierdzających poprawne działanie napędu.The paper presents a possible implementation of a sensorless low speed permanent magnet synchronous machine (PMSM) control. The test setup for this purpose consists of an individual and programmable back-to-back voltage inverter and a PMSM with nominal power of 12 kW and nominal speed of 600 rpm. The impact of cogging torque oscillations is identified, which cause significant problems in the implementation of a Field Oriented Control for low speed PMSM. In order to handle this torque oscillation problem a compensation method is proposed as well. A start-up procedure for the control system was implemented that allows a motor start without any rotor angle and speed sensors. The presented control method is based on the Field Oriented Control with PI stator current controllers in dq axes. Furthermore, the equations of the applied state observer are shown. The observer estimates all of the control variables necessary using phase current measurement and the information of the desired stator voltage. All theoretical assumptions are verified with experimental results, which show the proper operation of the low speed PMSM drive