Serwis Infona wykorzystuje pliki cookies (ciasteczka). Są to wartości tekstowe, zapamiętywane przez przeglądarkę na urządzeniu użytkownika. Nasz serwis ma dostęp do tych wartości oraz wykorzystuje je do zapamiętania danych dotyczących użytkownika, takich jak np. ustawienia (typu widok ekranu, wybór języka interfejsu), zapamiętanie zalogowania. Korzystanie z serwisu Infona oznacza zgodę na zapis informacji i ich wykorzystanie dla celów korzytania z serwisu. Więcej informacji można znaleźć w Polityce prywatności oraz Regulaminie serwisu. Zamknięcie tego okienka potwierdza zapoznanie się z informacją o plikach cookies, akceptację polityki prywatności i regulaminu oraz sposobu wykorzystywania plików cookies w serwisie. Możesz zmienić ustawienia obsługi cookies w swojej przeglądarce.
This paper presents a simple control structure for the stand alone operation of Self Excited Induction Generator used to operate under variable loads. The proposed system uses PWM Voltage Source Inverter, DC-DC Boost Converter and diode bridge Rectifier with SEIG. The required reactive power for the Self Excited Induction Generator is supplied by means of a capacitor bank and the PWM converter to...
This paper compares and analyzes two control methods (pulse width and phase shift modulation) for a new type of step-up DC/DC converters with galvanic isolation - the quasi-Z-source inverter (qZSI) based DC/DC converter. The proposed converter is suitable for applications, where the wide range of voltage gain is demanded, e.g. with renewable energy sources (fuel cells, photovoltaic cells), in telecom,...
For fluctuations of the DC bus voltage in dual PWM motor drive system, which is caused by the frequent changes in motor running, the generation mechanism is analyzed. A new control strategy for dual PWM system is proposed, which is based on EL model and the load power feed forward. By using DC steady state voltage compensation and the Power load forecasting, the stable DC voltage and the unity power...
This paper designed a double close loop control system based on current and voltage. As the system instable in some cases, the traditional PI regulator can not regulate the system more precisely. To make a more stable and better control effect, it should be improved by using Neural Network Control to get a feedback adaptive control system of PWM rectifier in order to achieve better results.
This paper describes voltage balancing of all the four split dc capacitors for a five-level diode-clamped PWM inverter intended for a transformerless mediumvoltage motor drive with a three-phase diode rectifier used as the front end. A dc-voltage-balancing circuit is installed on the dc link, and introduces a new midpoint-voltage-balancing method based on phase-shift control. As a result, the dc mean...
The main advantages of the high speed machine are small size and high power density. However, the high speed machine suffers from higher loss density and cooling difficulty due to small cooling area, especially the high frequency harmonic currents produced by the power conversion system increase the loss and temperature of high speed machine. The output high frequency AC power of the high speed PM...
This paper proposes to apply an AC/AC direct converter topology for servo systems. In the conventional AC/AC converter which consists of a PWM rectifier and a PWM inverter, the p-n junction temperature becomes high at the low output frequency or the servo-lock operation because the output current concentrates at the specific switching devices in the inverter. On the other hands, the AC/AC direct converter...
A novel main circuit topology of voltage quality compensator (VQC) is proposed in this paper, composed of PWM rectifier and cascade H-bridges inverter. The three phase inverter is decoupling controlled. PWM rectifier is adopted to maintain the dc-bus voltage stably and provide or absorb real power. The inverter is controlled by carrier phase shifting with FPGA. The simulation model is set up on the...
A three-phase PWM rectifier-inverter system for a PMSM drive with a single-chip micro-controller is presented. To reduce the cost of the system, the input/output currents and dc-link voltage are detected only using resistors. With the proposed sensorless control, neither an ac voltage/phase sensor nor a rotor speed/position sensor is needed in the system. All of the proposed control schemes can be...
Recently, importance of the effective use of energy and demand for the introduction of renewable energy have risen more than before. Therefore, it is necessary to construct power network systems that consist of semiconductor power converters with various functions such as generation of the electric power, storing and discharge of the electric power. This paper describes high-speed coordination control...
Voltage-source multilevel inverters have become very attractive for power industries in power electronics applications during last years. The main purposes that have led to the development of the studies about multilevel inverters are the generation of output voltage signals with low harmonic distortion; the reduction of switching frequency. A serious constraint in a multilevel inverter is the capacitor...
A method is presented to balance the two DC-link capacitor voltages for a three-level inverter. Previous work has shown that using the redundant states in space-vector PWM algorithm solves this problem, leaving lower order harmonics or using high switching frequency. Here, it is shown that, the redundant states can be used in selective harmonics elimination PWM in the case of multilevel inverters,...
This paper presents an analysis on electrolytic capacitor-less inverter and proposes a strategy for resonance suppression control for a DC-link voltage and input current in electrolytic capacitor-less inverter. The proposed electrolytic capacitor-less inverter can operate both in the motoring mode and regenerating mode owing to its inherent bidirectional power flow capability of the active front-end...
Reliability and power quality are two aspects of motor drives which have been gaining the attention of the industry. In fact, as the processes increased in number and complexity, the criticality of each component also increased. This paper proposes the usage of a PWM rectifier to accomplish a fault-tolerant motor drive with optimal performance and power quality. The system uses a hardware reconfiguration,...
This paper proposes a new control method of a current balancer for single-phase three-wire secondary distribution systems using the correlation and cross-correlation coefficients to reduce the capacity of the three-leg PWM inverter, which performs the current balancer. The components correlative and cross-correlative to the primary side voltage waveform, which correspond to the active and reactive...
Connected with drawbacks of the traditional AC-DC-AC inverters, the operation principles and the running characteristics of dual-PWM inverter are presented. In order to improve the DC bus voltage stability and the system reliability, the integrated direct power control strategy with power feedback is proposed, and the virtual-flux based direct power control schemes are introduced into the dual-PWM...
This paper describes a 6.6-kV adjustable-speed motor drive for pumps and blowers without transformer. The power conversion system consists of a front-end diode rectifier, a five-level diode-clamped PWM inverter with a voltage-balancing circuit, and a hybrid active filer for harmonic-current mitigation of the diode rectifier. A 200-V 5.5-kW downscale model is designed, constructed and tested with focus...
Recently, a new multilevel inverter-hexagram inverter has been reported for medium-voltage (MV) variable-speed drives (VSDs). This paper will propose a hexagram rectifier as the active front end for the hexagram-based MV VSD systems. The control of the hexagram rectifier is based on one-cycle control-an excellent control scheme for switching power converters. With the proposed control scheme, unity...
A three-phase PWM bidirectional converter system based on line voltage oriented vector control is researched. A novel on line voltage oriented vector control without line voltage sensing is proposed. The system is operated with unit power factor in the side of AC line no matter in rectifier mode or active inverter mode. The alpha and beta components of line voltage were estimated by the line current,...
This paper presents the applicability of generalized dynamic modeling of self-excited induction generator (SEIG) using state-space approach for wind energy system and control of output voltage by PWM strategy. A wind turbine is modeled for SEIG to make it applicable for wind energy system. The dynamic performance of SEIG under various wind speeds is investigated under no load, with the load, perturbation...
Podaj zakres dat dla filtrowania wyświetlonych wyników. Możesz podać datę początkową, końcową lub obie daty. Daty możesz wpisać ręcznie lub wybrać za pomocą kalendarza.