Article

An Improved Power-Quality 30-Pulse AC–DC for Varying Loads

Dept. of Electr. Eng., Indian Inst. of Technol., New Delhi
IEEE Transactions on Power Delivery (Impact Factor: 1.66). 05/2007; DOI: 10.1109/TPWRD.2007.893615
Source: IEEE Xplore

ABSTRACT This paper presents the design and analysis of a novel 30-pulse ac-dc converter for harmonic mitigation under varying loads. The proposed 30-pulse ac-dc converter is based on a polygon-connected autotransformer with reduced magnetics. The proposed ac-dc converter is able to eliminate lower than 29th order harmonics in the ac supply current. The resulting supply current is near sinusoidal in shape with low total harmonic distortion and a nearly unity power factor. Moreover, the design of an autotransformer is modified to make it suitable for retrofit applications, where presently a 6-pulse diode bridge rectifier is used. To validate the proposed approach, various power-quality indices are presented under varying loads. The proposed ac-dc converter is found to be suitable for retrofit applications with a large load variation and where harmonic reduction is more stringent. The laboratory prototype of the proposed autotransformer-based 30-pulse ac-dc converter is developed and test results are presented which validate the developed design procedure and the simulation models of this ac-dc converter

5 Bookmarks
 · 
647 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper presents 5-level, neutral point clamped, H-bridge inverter fed by 12-pulse rectifier. Two configurations of rectifier and inverter neutral point connection are studied: the first configuration with disconnected neutral points and the second configuration with connected neutral points. Furthermore, novel neutral point voltage balancing methods suitable for the presented configurations are proposed. Extensive simulation results of the proposed configurations with the neutral point voltage balancing methods are presented. The simulation results deal with aspects such as total harmonic distortion (THD) Factor of the inverter output currents, and voltages, grid current, harmonic content, frequency spectrum distribution. The results confirm the effectiveness of the proposed methods. The voltage balancing methods are compared and their advantages and disadvantages are explained.
    Electrical Engineering 12/2014; 96(4). · 0.35 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: The paper presents two configurations of 5-level, neutral point clamped H-bridge inverter fed by 12-pulse rectifier. In the first configuration, the neutral points of the rectifier and the inverter are not connected and in the second configuration they are connected. Three neutral point voltage balancing methods are proposed for these configurations. Extensive simulation results confirm the effectiveness of the proposed methods. The methods are compared and their advantages and disadvantages are explained.
    Electrical & Electronics Engineers in Israel (IEEEI), 2012 IEEE 27th Convention of; 01/2012
  • [Show abstract] [Hide abstract]
    ABSTRACT: In order to improve the ability of harmonic suppression, and reduce the loss of switching devices, this paper proposes an active harmonic suppression method at dc side of multi-pulse rectifier (MPR). The circulating current through secondary winding of active inter-phase reactor (AIPR) is derived from the current relation between the ac and dc sides of MPR when the three-phase input currents are sinusoidal simultaneously, and an applicable circulating current is presented. According to the relation between voltage across secondary winding of AIPR and the applicable current, it is confirmed that harmonic energy of input line current can be consumed by the resistor in series with the secondary winding. A half-bridge PWM rectifier is designed to abstract the harmonic power and to feed the load, which can realize the recycling of harmonic energy. Experimental results show that the power factor of the proposed system is approximately equal to one when the PWM rectifier operates normally, and that the proposed system has the ability of anti-variation of load and input voltage.
    Science China Technological Sciences 12/2011; 54(12). · 1.11 Impact Factor