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A PWM Method for Single-Phase Current-Sourced High Frequency AC Link Inverter
... Dalam penelitian ini metode yang digunakan adalah perancangan obyek penelitian berupa sebuah sistem inverter DC to AC dengan bagian keluaran inverter dipasang filter EMI common mode (Haghdar, 2020;Kim et al., 2020;Kim et al., 2018). Metode ini meliputi perancangan hardware sistem konversi energi DC to AC. Pendalaman materi untuk menjelaskan keluaran inventer terhadap total harmonik distorsi (THD) terhadap beban induktif, beban resistif, beban kapasitif sebelum dan sesudah dipasang filter EMI (Dermawan & Rahman, 2018;Juhana & Rozak, 2022). ...
Agar tidak terputus dengan sumber energi listrik maka di perlukan sistem backup. Salah satunya adalah dengan sistem charging di saat PLN menyala dan menyimpannya di akumulator untuk di gunakan pada saat pemadaman oleh PLN. Namun pada saat charging dilakukan listrik yang di simpan ke akumulator berupa arus DC sehingga perlu di rubah kembali ke arus AC yaitu dengan inverter AC to DC. Sistem inverter menggunakan swiching yang menimbulkan harmonisa. Gangguan pada sistem tenaga listrik yang di akibatkan oleh distorsi gelombang dan arus di sebut harmonisa. Harmonisa bisa menyebabkan kerusakan gelombang sinusidal menjadi tidak sinusidal lagi yang di sebabkan oleh gelombang frekuensi tinggi yang merupakan kelipatan dari frekuensi fundamental. Untuk mereduksi harmonik adalah dengan pemasangan filter emi pada output inverter. Penelitian ini mengukur berapa nilai efektifitas pemasangan filter menggunakan software Labview 2014 pada inverter custom low inverter 500 watt dengan beban induktif, resistif, kapasitif menggunakan software labview dan instrument NI Mydaq. Hasil dari penelitian adalah di perlukan daya stanby/tanpa beban pada filter emi common mode sebesar 0.03 Amper pada tegangan 220VAC. Pada kondisi tanpa beban terjadi kenaikan pada THDv sebesar 0.03 dari sebelum filter 1.7% menjadi 1.739%, dan penurunan THDi 0.12 dari 1.311% menjadi 1.119%. Pada kondisi dengan beban induktif terjadi penurunan pada THDv sebesar 0.104 dari sebelum filter 1.202% menjadi 1.098%, dan THDi sebesar 0.099% dari sebelum filter 1.325% menjadi 1.226%. Pada kondisi dengan beban resistif terjadi penurunan pada THDv sebesar 0.12 dari sebelum filter sebesar 1.218% menjadi 1.09%, dan THDi sebesar 0.003 dari sebelum fiter 1.144% menjadi 1.114%. Pada kondisi dengan beban kapasitif terjadi kenaikan pada THDv sebesar 0.185 dari sebelum filter sebesar 1.219% menjadi 1.404% dan mengalami penurunan pada THDi sebesar 0.035 dari sebelum filter sebesar 1.44% menjadi 1.109%. Kata Kunci: Filter Emi, Harmonisa, Inverter, LabView, Reduksi
... Another soft switch half wave cycloconverter is addressed in [23], where four MOSFETs are used that increases total conduction losses and even equipment costs. Nevertheless, there are more topologies proposed by the authors including AC-AC matrix converter [24], high-frequency ac link converters [25], variable frequency drive converter (VFD) [26], current source cycloconverter [27], envelope cycloconverter [28] which use an unsatisfactory number of switching components as compared to the conventional cycloconverter in order to enhance the overall performance of the system. ...
This paper presents a novel single-phase to single-phase multiconverter topology that can be applied in multiple areas. The proposed multiconverter is designed with only two soft power semiconductor switches (e.g. MOSFET or IGBT), four power diodes and a center-tapped transformer which makes it more compact in size, decrease the gate driving complexity, reduce the total equipment costs and enhance the energy conversion efficiency with minimized losses. Furthermore, the utilization of the transformer in the proposed converter mitigates the multiple AC source requirement problems and provides galvanic isolation which increases the reliability of the converter. Moreover, the presented multiconverter is applicable in various areas including electric traction as a speed controller, induction heating, AC and DC variable power supplies, etc. which signify the competence of this converter in energy conversion appliances. However, a comparative analysis of the offered converter with the existing AC-AC converters is also introduced in this paper with respect to the number of components, equipment costs, gate driving complexity, and application areas. In order to evaluate the performance of the proposed multiconverter, the simulation-based results carried out in MATLAB/Simulink are presented and analyzed in this paper with proper descriptions. Finally, a scaled-down prototype is developed in the laboratory to validate the simulation results and the feasibility of the proposed multiconverter.
In power electronic equipment, magnetic devices are important parts, and their working condition and reliability are closely related to turn‐to‐turn insulation. With the increasing application of high‐frequency square wave voltage in the fields of frequency conversion technology and motor control, the high voltage stress on magnetic devices will accelerate insulation aging, so it is necessary to monitor the aging state of turn‐to‐turn insulation. At present, researchers mainly detect insulation aging by detecting partial discharge signal. However, this method cannot realize the early monitoring of aging, and the measurement cost is high and the accuracy is low. Therefore, for the dry‐type core reactor with epoxy resin as the insulation medium, this paper proposes a turn‐to‐turn insulation aging state detection method under high‐frequency square wave voltage excitation. According to the relationship between the turn‐to‐turn insulation aging state of the reactor and its parasitic capacitance, the turn‐to‐turn insulation aging degree of the reactor is predicted by measuring and analyzing the phase information of high‐frequency components of the current signal. Finally, the measuring principle and method are introduced and verified by experiments. This paper proposes a method to detect the turn‐to‐turn insulation aging state of dry‐type core reactor under high‐frequency square wave voltage excitation. According to the relationship between the turn‐to‐turn insulation aging state of the reactor and its parasitic capacitance, the aging degree of the insulation is predicted by measuring and analyzing the phase information of high‐frequency components of the current signal. In this paper, we verify the theory and method with experiments.
A technique for commutating the load current of a high-frequency link, pulse-width modulated cycloconverter is presented. As the load current makes a sign transition, switch operation becomes critical to avoid commutation failure. Previous techniques required either dead time or the use of large inductors to limit shoot-through current, thereby compromising performance and efficiency. The technique presented here identifies the switching sequence that is necessary to allow load current to commutate naturally without distortion. The switching sequence is managed with a state machine.
Fuel-cell inverter applications typically have a relatively low voltage input, and require a battery bus for energy buffering. Circuit topology issues are examined based on these needs. The need for high step-up ratios, current control, low ripple, and battery storage leads to a current-sourced link converter as perhaps the best choice of conversion topology. High-frequency ac link conversion offers a possible way to reduce the number of power stages, in the form of a cycloconverter, known from previous work. It is shown that the control complexity in this converter can be addressed by adapting pulse-width modulation (PWM) techniques. Here, a multicarrier PWM approach is introduced as a convenient way to implement a high-frequency link inverter. The approach is a direct extension of conventional PWM, and supports square-wave cycloconversion methods that have appeared in prior literature. Simulation and experimental results are developed for a low-voltage ac link inverter, leading to a 48-V fuel cell input design.
Conventional SCR based current source inverters suffer from poor
waveform quality due to six step switching. Pulse width modulated
current source inverters typically require gate turn off devices with
reverse voltage blocking capability which have limited their
application. In this paper, a new pulse width modulated current source
inverter topology using one gate turn off switch and six SCRs is
presented. The converter uses active commutation to realize pulse width
modulation in a conventional SCR based current source inverter.
Modulation techniques for the proposed inverter, simulation and
experimental results are described in the paper. This topology is
suitable for high performance, high power applications
This paper discusses a new PV-Module Integrated Inverter (PVMII) topology that is ideally suited for use in single-phase grid-connected PV application. The proposed MII is based on bipolar, AC-link principle, so there are no electrolytic capacitors, and a new power decoupling approach, which can use the minimum value of decoupling capacitance. Hence, a very small, highly reliable film capacitor is cost-effectively used, which also improves dramatically the reliability compared to dc-link topologies with electrolytic capacitors. Further, the proposed MII allows bidirectional power flow; a beneficial feature for advanced grid-support features such as local energy storage and reactive power compensation.
There are many defects in the traditional SPWM inverter, for example, large size, heavy weight, too much noise etc. For these reasons, it canpsilat reach the technical requirements of vehicle hold electrical-source inverter. High frequency inverse technology is used to solve these defects. Dividing inverse process into two parts: DC-DC previa section and SPWM inverse section. The inverterpsilas performance is improved by placing voltage-rising section in the DC-DC previa section, and by replacing fundamental frequency transformer with high frequency transformer, as a result, the inverterpsilas size and weight is reduced at the same time. This article shows the system structure and working principle of a new type vehicle-hold electrical-source inverter, the design of systempsilas software and hardware, which transformed 40 V DC power into 220 V/50 Hz AC power successfully.
This paper studied the control of current source inverter (CSI) used in direct-drive wind power generation system, where CSI serves as the actuator of the control and optimization of the system besides the grid inverter. This function of CSI is realized through the control of CSI dc terminal voltage Vdc. Two factors which exert restrictions on the control of Vdc were analyzed. The first one is the limits caused by the grid-connected transformer primary voltage on achievable Vdc range. The second one is the restriction on practical Vdc range for the continuity of dc-link current td. According to analysis results, the control principles of Vdc were derived.
This paper describes a current-fed high frequency (HF) link direct DC/AC converter suitable for fuel cell power source. The proposed current-fed HF link direct DC/AC converter consists of a current-fed full-bridge inverter with an active harmonic filter, a HF link transformer, and a simple cycloconverter. The high frequency full-bridge inverter at the primary generates sinusoidally PWM modulated current pulses with zero current switching (ZCS), and the cycloconverter at the secondary which consists of only two bidirectional switches and output filter capacitors produces sinusoidally modulated 60 Hz split single phase output voltage waveforms with near zero current switching. An optional active harmonic filter connected to the input terminal compensates the low order input current harmonics drawn from the fuel cell without long-term energy storage devices such as batteries and super capacitors. The basic concept and operation of the proposed current-fed HF link DC/AC converter and active harmonic filter are presented. The various simulation results are provided to verify the feasibility of the proposed DC/AC converter.
A grid-commutated thyristor inverter based power electronic interface for a direct-drive modular permanent magnet generator in a variable-speed wind energy conversion system is described. The AC/DC/AC power electronic interface consists mainly of a diode rectifier and a thyristor inverter. The inverter ignition angle can be adjusted continuously to control turbine speed so that the optimal energy capture is achieved. The reactive power and harmonic characteristics of the thyristor converter system have to be compensated to meet the standards for grid connection. An active compensation system is discussed to minimise the harmonic distortion and to provide reactive power control. A simple method of deriving the reference current for the active compensator is proposed on the basis of optimal operation conditions. Several compensation schemes are considered. Experimental results from a laboratory model are presented along with computer simulation results, which are in good agreement.
A new high frequency link inverter on vehicle
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