Compensating Characteristics of a Series-Shunt Active Power Filter Considering Unbalanced Source Voltage and Unbalanced Load

Enhancing Electric Power Quality Using UPQC: A Comprehensive Overview

“…The back-to-back inverter system configuration truly came into attention when Fujita and Akagi [14] proved the practical application of this topology with 20 kVA experimental results. They named this device as unified power quality conditioner (UPQC), and since then the name UPQC has been popularly used by majority of the researchers [15], [18], [20]- [26], [28], [29], [31]- [67], [69]- [79], [81]- [145], [147]- [168]. The back-to-back inverter topology has been also addressed as series-parallel converter [12], unified APF (UAPF) [13], universal active power line conditioner [16], [27], universal power quality conditioning system (UPQS) [19], load compensation active conditioner [30], [57], universal active filter [146], and so forth.…”

“…During the system dynamic conditions, for example, sudden load change, voltage sag, the dc-link feedback controller should respond as fast as possible to restore the dc-link voltage at set reference value, with minimum delay as well as lower overshoot. The proportional-integral (PI)-regulator-based dc-link voltage controller is simple to implement and hence widely used by the researches [12]- [14], [16]- [20], [22], [23], [26]- [33], [36], [38], [40], [42], [46]- [48], [50], [54], [56], [60], [61], [64], [67], [68], [75]- [77], [81]- [84], [88]- [90], [92], [94], [95], [100], [103]- [105], [108], [109], [111]- [114], [116], [117], [119], [122], [124], [126]- [128], [130]- …”

“…However, the cutoff frequency of these LPF or HPF can affect the dynamic performance of the controller. The UPQC controller based on three-phase pq can be found in [14], [16], [17], [27], [32], [52], [98], [104], [109], [113], [114], and [126], while dq method based controller can be found in [12], [18], [19], [22], [25], [26], [33], [45], [47], [68], [75], [81], [84], [88], [89], [95], [105], [111], [112], [114], [117], [121], [128], [135], [143], [152], [153], [158], [161], and [167]. The original three-phase pq theory exhibits limitations when the supply voltages are distorted and/or unbalanced.…”

“…A special attention on compensating the problem of voltage flicker [14], [31], [45], [46], [144], [155] and/or voltage unbalance [81], [117], [144], [166] can be noticed. The UPQC could be the most effective power quality conditioner to solve the flicker problems caused by an arc furnace load [14], [31],] [45], [47].…”

“…In [127], authors have used fault current limiter to reduce the UPQC rating particularly by limiting the excessive current during the event of a fault. Finally, it is found that throughout the development phases of UPQC, researchers have given equal importance to evaluate the control algorithm and overall UPQC system performance by experimental investigation [11], [14], [22], [23], [26], [33], [40], [42], [51], [52], [56], [57], [60], [63], [75], [80], [81], [89], [94], [97], [107], [109], [114], [116]- [118], [120], [129], [143]- [145], [147], [150], [155]- [157], [159], [161], [163], [164], [167], [168]. A 250-kVA UPQC system is developed at the Centre for the Development of Advanced Computing (C-DAC), Thiruvananthapuram, India [75].…”