Shunt active power compensator/photovoltaic generator for delta loads using the symmetrical components transformation

Selective Shunt Active Power Compensator in Four Wire Electrical Systems Using Symmetrical Components

“…(5) according to the different phenomenona present in the electrical system. Three instantaneous power terms appear due to single-phase linear loads connected to three-phase systems [15][16][17][18]: the effective active fundamental instantaneous power (p e1 (t)), the reactive fundamental instantaneous power (p q1 (t)) and the fundamental unbalance instantaneous power (p U 1 (t)).…”

“…(11), the positive-sequence reactive current and the negativeand zero-sequence components of the fundamental voltage and current are not desirable in the electrical systems [2,[16][17][18]. These terms represent inefficiencies that must be compensated to reach the maximum efficiency in the electrical system.…”

“…Following the procedure described in [1], the value of K v is expressed in Eq. (18). (18) where C dc is the DC bus capacitance, V * dc is the DC bus reference voltage, V dc is the difference between the DC bus reference voltage and the DC voltage (obtained as the sum of voltages in the top and bottom capacitance), f 1 is the fundamental frequency (50 Hz) and V + 1 is the rms positive-sequence voltage.…”

“…(18). (18) where C dc is the DC bus capacitance, V * dc is the DC bus reference voltage, V dc is the difference between the DC bus reference voltage and the DC voltage (obtained as the sum of voltages in the top and bottom capacitance), f 1 is the fundamental frequency (50 Hz) and V + 1 is the rms positive-sequence voltage. The integral part of the PI regulator in Figure 7 is provided by the DC bus capacitance.…”

Photovoltaic inverters used as active filters for improvement of IV distribution networks

“…So, the unique function they have traditionally faced is to inject as much current as possible in phase with the voltage at the point of common coupling (PCC). However, these electronic power converters could be used not only as simple current controlled inverters but also as active power filters (APF), trying to improve the power quality in the EPS [2][3][4]. The capability of filtering of these systems is greatly affected by the technology implemented (switching devices), by their topology, by the used modulation techniques, by the programmed control systems that regulate the output variables of the inverter, and by the location and rated power of the equipment.…”