A Control Method for Static VAR Compensator Based On Modular Multilevel Inverter

Multilevel inverters are promised to provide a better performance in high power applications such as static VAR compensators. The proposed modular inverter has advantages compared to the conventional technologies. A control system of static VAR compensator using new modular multilevel inverter is proposed in this paper. Modeling and dynamic performance of static VAR compensator based on the proposed multilevel inverter are described in this paper. The inverter switching devices are switched at the fundamental output frequency. How to control the dc capacitor voltage is described. Several simulated results are included to verify the proposed concept. Keywords: Multilevel, inverter, STATCO

A CONTACTLESS POWER STATION FOR CELLULAR BATTERY CHARGER

A Contactless Power Station (CLPS) is a new breakthrough to transmit power without wires in electronic devices such as cellular phones. Power transfer capability of a CPLS system can be increased if the system is designed to operate under resonance condition. The power transfer is then controlled by controlling the inverter frequency. In order to ensure that the power transfer is maximum, a maximum power point tracker is employed to control the CLPS. Several simulated and experimental results are included

Analysis of Output Current Ripple of Three-phase PWM Inverter under Discontinuous Modulation Techniques

In this paper, an analysis of output current ripple of three-phase PWM inverters with discontinuous modulation is presented. The analytical expressions for discontinuous modulation injection signal are derived. It is followed by derivation of rms value of output current ripple of three-phase PWM inverter as a function of modulation index. Analysis of the influence of injection signal phase shift of the rms output current ripple three-phase PWM inverter is given. It is shown that at the same switching frequency with sinusoidal PWM, the discontinuous PWM produces lower rms output current ripple at high modulation index. A 30° lag phase shift results in lower rms output current ripple. Phase shifting from symmetrical discontinuous PWM gives lower modulation index. Simulation results are included to verify the derived expressions

Design and Analysis of Three-Phase Three-Level PWM Inverter

Design of three-phase three level PWM inverter and analysis of the output current harmonics are presented in this paper. The three-level inverter is designed to supply three-phase load and it is controlled by FPGA under several modulation techniques (Sinusoidal PWM and Third Harmonic Injection PWM). Selection of semiconductor switches and other component of the inverter are described. Inverter output current harmonics under several modulation techniques will be analysed and compared

Pengendalian Inverter Resonan DC

Sari. Pada makalah ini, dibahas teknik kendali inverter resonan sisi DC jenis tegangan dan jenis arus. Ditunjukkan dalam makalah ini bahwa teknik kendali yang telah dikembangkan untuk mengendalikan inverter resonan jenis tegangan bisa diterapkan untuk mcngendalikan inverter resonan jenis arus. Pada inverter resonan jenis tegangan, arus mula di induktor resonan harus dikendalikan sedemikian rupa sehingga bias djamin bahwa tegangan di kapasitor resonan akan kembali ke nilai nol di akhir perioda resonansi dan mempunyai nilai puncak yang minimum. Sebaliknya, pada inverter resonan jenis arus, tegangan mula di kapasitor resonan harus dikendalikan sedemikian rupa sehingga bisa dijamin bahwa arus di induklor resonan akan kembali ke nilai nol di akhir priode resonarsi dan mempuryai nilai puncak yang minimum. Kesahihan konsep yang diusulkan ini diuji dengan membandingkannya dengar hasil percobaaan. A Control Method for Resonant DC Link InvertersAbstract. This paper presents a control method for voltage-type and current-type resonant DC link inverters. It shows that the control method that has been developed for voltage-type resonant DC inverters can also be applied to the current-type ones. In voltage-type resonant DC link inverters, the initial current of resonant inductor is controlled in such a way to ensure that the resonant capacitor voltage will return to zero at the end of each resonant cycle. On the other hand in current-type inverters, the initial voltage of resonant capacitor is controlled n such a way so that the resonant inductor current will return to zero at the end of each resonant cycle. Validity of the proposed control method is verified by experimental results

Analisis Motor Tak Serempak Tiga-Fasa dengan Metoda Park Komplek

Tulisan ini menyajikan analisis untuk kerja mesin listrik jenis non-salien. Analisis kwantitatif dilakukan dengan metoda Park d, q yang digeneralisasi, dengan menempatkan sumbu d, q pada sudut sembarang, untuk mencari bentuk umum persamaan Park komplek. Untuk menunjukkan bahwa teori ini berlaku umum dan dapat diterapkan pada hal khusus, maka diambil contoh pengasutan motor tak serempak dengan tegangan tiga-fasa sinusoidal dan inverter otonom tiga-fasa yang mencatu motor tak serempak. Persamaan listrik motor tak serempak yang dinyatakan dalam bentuk Park komplek menjadi lebih sederhana, sehingga penyelesainnya lebih mudah. Dari hasil simulasi dapat diketahui besaran listrik maksimum yang diperlukan dalam disain inverter dan motor listrik. Performance analysis of non-salient type of electrical machines is described in this paper. Based on the d-g Park's equations the general form, i.e. by placing the d-q axes at an arbitrary angle, of Park complex equations are derived. The general applicability of this theory is verified by two examples, i.e. the direct on line starting of asynchronous motor and the inverter fed asynchronous motor. It is shown in this paper that the performance equations of asynchronous machines in Park's complex form are simpler, and furthermore simplify the solution. Important design informations for inverter and electrical machines such as the peak values of electrical parameters are provided by the simulation results

A New Voltage Control Method for Single-Phase PWM Inverters

A  new  voltage  control  method  for  single-phase  full-bridge PWM inverters  that having an output LC filter  is proposed in this paper. The proposed voltage  controller has a capability to realize a zero steadystate output voltage error with fast response. The zero steady-state output voltage error is achieved by using a controller that is derived by using the virtual LC resonant circuit. Fast response is obtained by using a virtual resistance  that  is  connected  in  parallel  with  the  filter  capacitor.  The validity of the proposed method is verified by experimental results

Optimum Phase Number for Multiphase PWM Inverters

This paper investigates the optimum phase number for multiphase PWM inverters. The input current ripple is used as  a  performance  indicator.  Analysis results  show  that  phase number more than nine cannot provide significant input current ripple reduction. Experimental results are included in this paper to show the validity of the proposed analysis method

A New Voltage Control Method for Single-Phase PWM Inverters

A new voltage control method for single-phase full-bridge PWM inverters that having an output LC filter is proposed in this paper. The proposed voltage controller has a capability to realize a zero steadystate output voltage error with fast response. The zero steady-state output voltage error is achieved by using a controller that is derived by using the virtual LC resonant circuit. Fast response is obtained by using a virtual resistance that is connected in parallel with the filter capacitor. The validity of the proposed method is verified by experimental results