The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This paper deals with a voltage disturbance generator output characteristics. Usually a microgrid is connected to utility grid through STS to disconnect in case of fault occurrence. The STS should be opened in case of outage, however, it may be connected in case of voltage sag occurrence. The magnitude of surge or over current through the STS is determined by the dip of the sag. The voltage disturbance...
This paper presents a single-phase dynamic voltage restorer (DVR) equipped with a high-frequency isolated soft-switching converter. The proposed DVR can maintain the load voltage stable and lower the harmonic distortion. Moreover, by using simple resonant units, all main switches are operated at zero-voltage-switching (ZVS) turn-on mode. Simultaneously, other auxiliary switches are operated at zero-current-switching...
Photovoltaic (PV) energy has been widely interested today because it is clean and endless energy without causing pollution. To produce electricity from solar energy, it would be required an inverter to convert the direct current into alternating current. The inverter is the cause of problems that affect the stability of the power system because it is a switching device served to adjust the frequency...
Lighting system is an important part in everyday life. Today, lighting technology has been developing in many aspects. Technology such as Light Emitting Diode (LED) luminaire has been applied to indoor lighting system to replace conventional luminaire. LED lamps have many advantages such as less energy consumption, long life cycle and environmental friendly issue due to without toxic component. However,...
The ac-ac converters with bipolar voltage gain are desired for utility voltage compensation. In this paper, a single-phase buck-boost ac-ac converter is proposed with versatile operating modes and bipolar voltage gain capability. It consists of six bidirectional voltage blocking switches and an inductor, apart from input/output filtering capacitors. The key features include no shoot-through or commutation...
For high PV penetration, grid ancillary services such as dynamic voltage support and low-voltage ride-through (LVRT) operation are recommended by network operators. This paper proposes an integrated controller for LVRT capability of a three-phase grid-tied PV system connected to a LV grid. Generally X/R ratio is low for LV grids, therefore the active power injection is given higher priority than the...
This paper proposes an ac-ac converter with bipolar voltage gain. It has both inverting and non-inverting operations. It has no shoot-through problem of voltage source or capacitor and can eliminate pulse-width modulation (PWM) dead-time between the switches, therefore high quality output ac power can be obtained and reliability of system can be improved greatly. The proposed converter can compensate...
Power factor displacement and voltage fluctuation might produce due to high reactive power consumption of loads or long distribution lines. These power quality problems need more consideration in islanded microgrids (MGs) due to operating in low voltage grid with the absence of main grid. In this line, a novel control strategy for static synchronous compensator (STATCOM) is proposed in this paper...
This paper addresses compensation performance of the constant dc-capacitor voltage-control (CDCVC)-based strategy for smart charger with the previously proposed reactive power control algorithm in single-phase three-wire distribution feeders (SPTWDFs) under distorted source voltage conditions. The instantaneous power flows into the smart charger is discussed in detail. This instantaneous power flowing...
The introduction of catenary-free light rail transits (LRTs) in currently urban transportation systems becomes tendency and attractive alternative to traditional fuel cars and LRTs with overhead contact systems. This type of LRT trains are powered through onboard energy storage systems which are elements in an infrastructure that supplies electric energy for recharging of the LRT trains, which requires...
When a severe grid voltage sag has happened, the transient rush current caused by grid voltage sag can not be effectively suppressed by the voltage controlled grid tied inverter based on the conventional virtual synchronous generator(VSG) control. In order to improve the capacity of voltage controlled grid tied inverter to withstand power grid voltage sag, the paper proposes an enhanced robust strategy...
Photovoltaic (PV) systems are integrated into the distribution network (DN) through the grid tied inverter. This paper proposes a flexible power control scheme (FPCS) for three-phase inverters which can compensate the load asymmetries imposed by the nearby residential loads. The development of the control scheme is based on: a dynamic estimation of the load current sequences through a Compensator...
This paper proposes a control method to expand a fault-ride-through (FRT) operation range for a grid-tied matrix converter. In the conventional method, the generator current is limited because the q-axis current is only controlled whereas the d-axis current is kept to zero. Consequently, the matrix converter cannot satisfy the FRT requirements for the grid reactive current due to the limitation of...
As the penetration level of grid-connected Photovoltaic (PV) systems increases, the power quality is one of the major concerns for system operators and the demands are becoming even stricter. The impact of interharmonics on the grid has been acknowledged in recent research when considering a large-scale adoption of PV inverters. However, the origins of interharmonics remain unclear. Thus, this paper...
Periodic signal controllers like repetitive and resonant controllers have demonstrated much potential in the control of power electronic converters, where periodic signals (e.g., ac voltages and currents) can be precisely regulated to follow references. Beyond the control of periodic signals, ac signal processing (e.g., in synchronization and pre-filtering) is also very important for power converter...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.