A novel solar panel optimizer with self-compensation for partial shadow condition

Abstract

The energy utilization efficiency of PV panel can be significantly affected by the partial shadow effect. Traditional solutions mainly focus on panel-level optimization but ignore the partial shadow happens on sub-string level which may also affect the efficiency. In this paper, a novel solar panel power optimizer with selfcompensation for partial shadow condition is proposed. The optimizer can realize self-compensation for the unbalanced part inside the PV panel without changing the electrical connection. At the same time, the optimizer, which is implemented by simple multi-winding flyback topology, draws the compensation current from the output of the same panel, so that no other source is required for compensation. The simulation and experimental results show that the output power of the PV panel under partial shadow condition is significantly increased by applying the proposed circuit.

Shadowing compensator for grid-connected photovoltaic generation system

“…However, many power electronic switches must be used in this topology and it cannot compensate for the power loss in the shaded solar cells between the bypass diodes of a solar module. A system of self-compensation that uses a multi-winding fly-back converter is seen in a solar module in [18]. In this method, the power source of the multi-winding fly-back converter is the output of the partially shaded solar module itself and the sub-strings of solar module are compensated by the power of the same solar module.…”

Single-Switch Voltage Equalizer Using Multistacked Buck–Boost Converters for Partially Shaded Photovoltaic Modules

“…With DPP converters or equalizers, a fraction of the generated power of unshaded substrings is transferred to shade ones so that all the substrings operate at the same voltage or even at each MPP. Various kinds of DPP converters and equalizers have been proposed and developed [5]- [25], the representative topologies of which are listed in Fig. 2.…”

“…2(a)-(c), such as buck-boost converters [5]- [12], multi-stage choppers [16], [17], switched capacitor converters [18], [19], and other topologies [13]- [15], [20]- [23], more than one switch per substring is required as a minimum, meaning the switch count tends to soar with increasing the number of substrings/modules. With the multi-winding flyback converter [25] shown in Fig. 2(d), the switch count can be reduced to one, simplifying the circuitry.…”

Two-Switch Voltage Equalizer Using an LLC Resonant Inverter and Voltage Multiplier for Partially Shaded Series-Connected Photovoltaic Modules

“…Various kinds of differential power processing (DPP) converters and voltage equalizers have been proposed and developed to address issues on partial shading in series-connected PV modules [2]- [24]. These converters transfer part of the generated power of unshaded PV modules to shaded modules so that all the individual PV modules connected in series can operate at virtually the same voltage or even each MPP.…”

“…In the multi-winding flyback converter [24], shown in Fig. 2(d), the number of switches can be minimized.…”