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 describes a current sharing technique for digitally controlled two-phase buck DC-DC converters where pulse width and resistance mismatches are digitally compensated to achieve approximately equal current sharing without sensing currents. Effects of various non-idealities on the current sharing performance are discussed and corresponding mitigation techniques are presented. An extension...
Constant frequency inverters, such as the 60 Hz 120 V UPS or the 208 V 3-phase power system may be paralleled with the utility for backup power or paralleled with similar supplies to increase output capabilities. Previous research has addressed paralleling 3-phase 4-wire inverters. This paper will examine the parallel operation of 2 similar 3-phase 4-wire inverters using repetitive control. Repetitive...
This paper focuses on the research of dual-loop digital control for PWM inverters. A method based on pole assignment is proposed to tune the control parameters. To avoid one-timestep delay caused by the sampling and calculating time of digital processors, design of state observer and disturbance observer are brought in. Due to the ripples of DC voltage and dead time effect, an un-neglected predict...
Current regulation plays a key role in modern power electronic AC conversion systems. The most obvious strategy is to use a simple closed loop PI regulator. However it is well known that this approach cannot achieve zero steady state error because of the instability that inevitably occurs as the PI gains are increased to reduce this error. Linear analysis identifies that an AC load controlled by a...
This paper introduces a digital controller and a segmented power stage that dynamically change mode of operation to maximize power processing efficiency when highly dynamic loads are supplied. The controller operates as a mixed-signal peak current program mode voltage regulator, where a digital current reference is created and used for the efficiency optimization. The losses of the power stage are...
In this paper a fast flux search controller based on the Neuro-fuzzy systems is proposed to achieve the best efficiency of a direct torque controlled induction motor at light load. In this method the reference flux value is determined through a minimization algorithm with stator current as objective function. This paper discusses and demonstrates the application of Neurofuzzy filtering to stator current...
A crucial component of a grid-connected converter system is the phase-locked loop (PLL) that synchronizes the control to the grid voltage. Accurate, fast responding PLLs are required to provide phase angle and frequency measurements of the grid voltage for control and protection purposes. This paper proposes novel feedback mechanisms using the estimated frequency and phase in single-phase PLLs (in...
If a power factor corrector (PFC) is designed with a fast output-voltage feedback loop, both the steady-state and the dynamic behaviour of this PFC vary in comparison with that obtained when its output-voltage feedback is slow. This is a consequence of the voltage ripple that appears on the control signal, which modifies the converter operation. This voltage ripple is quantified by defining two parameters:...
This paper presents a bidirectional 3X dc-dc multiplier/divider that can interface the battery with the inverter dc bus for hybrid electric vehicle (HEV) traction drives. Compared with traditional multi-level dc-dc converter, this converter can have three output/input voltage ratios with smooth transition. The control method to limit the transient inrush current, as well as a novel regenerative clamping...
In this paper, a predictive non-linear voltage mode control method is introduced to enhance the transient performance of the VR. The proposed control method enables the VR to operate at a lower switching frequency in 250 KHz range for higher efficiency during steady state operation but respond fast accordingly to transient events when necessary. Compare to conventional method, the proposed control...
In this paper an approach of a step-up/down dc-dc converter with wide range conversion called Boost2-Buck is presented. The proposed converter presents nonpulsating input and output current. It has operations equivalent to a cascade converter consisting of two boost converter and one buck converter, but with the advantage of using single active switch. Mathematical analysis and experimental results...
A dual-voltage-loop digital control architecture with non-linear control algorithm is proposed in this paper. An adaptive voltage positioning (AVP) control unit was generalized to achieve adaptive voltage positioning, by generating dynamic voltage reference and dynamic current reference. A dynamic reference step adjustment method lowers the high speed requirement of reference updating clock; a non-linear...
The availability of T5 high-efficiency (HE) and high-output (HO) fluorescent lamp families not only increases the number of commonly used tubular fluorescent lamps from 9 to 18, but more importantly, increases the chance of ballast-lamp mismatch because T5(HO) and T5(HE) lamps have similar physical outlooks and dimensions but vastly different lamp characteristics. The large number of lamp types increases...
In this paper we propose two three-phase series active power filters (SAPF) for voltage harmonic compensation and voltage regulation. The power filters are conceived to operate without isolation transformer and auxiliary active dc source. The topologies are adequate for applications in which the load or grid terminals are accessible. The model of the systems are derived to analyze their behavior for...
The important characteristics of parallel-connected uninterruptible power supply (UPS) systems are excellent power-sharing quality and stability. In this paper we use the output active and reactive power to adjust the output voltage amplitude and phase to achieve the load sharing. Because of the difference of output filter inductor's resistance and distance of connection wire of each machine in the...
This paper make uses of the instantaneous symmetrical components transformation to deal with the cross-coupling terms and the order doubling issue, then a new current regulator design approach is proposed. The theoretical identicalness between the proposed regulator and the synchronous PI regulator is proven, and both the simulation and the experimental results verify the analysis.
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.