Decoupled model of the PWM voltage converter connected to the AC mains

Abstract

Two detailed and two global models and their respective control circuits for the PWM voltage converter connected to the AC mains are presented. The fist state model is a d q Park axis coupled system. In the second model decouplmg is achieved. With the decoupled system it is possible to control independently the Park's coordinates of the converter AC currents and thus the active and the reactive power flow between the converter and the mains. It is also possible to inject current harmonics in the grid and cancel the mains AC currents harmonic content.

Harmonic estimation using RLS algorithm and elimination with improved current control technique based SAPF in a distribution network

“…(19) and (20) that mutual interference terms L fs wI q and L fs wI d exists in the d-and q-axis current control loops. Therefore the voltage decouplers are designed to decouple the current control loops and simplify the control scheme [11,14,16].…”

“…d ¼ tan À1 f nq f nd ð35Þ I m acts in the PCC voltages amplitude and d acts in the phase shift of converter voltages respectively [17,19]. The angular position of the converter voltages is obtained by adding the input phase angle d to wt, and the amplitude of the converter defined as the product of I m and V dc .…”

“…However, these passive filters based on resonant principle have many disadvantages, such as their inability to compensate random harmonic variation, large size, tuning problems and parallel resonance [9,10]. To overcome these problems, shunt connected custom power devices called shunt active power filter (SAPF), have been reported and considered as a possible solution for reducing current harmonics and improving the power factor [9][10][11][12][13][14][15][16][17][18][19][20]. The SAPF operates by injecting the reactive and harmonic components of load current into the utility system with the same magnitudes but with opposite phases.…”

Achieving near unity power factor in three-phase diode bridge rectifier-inverter structure

“…, the phase a current cannot be well limited in the hysteresis boundary and the rectifier fails to achieve high power factor goal. Substituting (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21) and (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23) into (4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15)(16)(17), the local average cu...…”

“…These methods are classified and reviewed here, advantages and disadvantages of each converter are also analyzed. [20][21][22][23][24][25][26][27]. Voltage source converter can provide a high performance while the high switching power losses limits its application on high power conversion.…”