Hysteresis SVM for Coupled Inductor Z Source Diode Clamped 3-level Inverter based Grid Connected PV System

Abstract

Due to its advantages such as it can defeat problems such as leakage current and insertion of DC in the grid and provides low stress on power devices, Diode-clamped three-level inverter (DCTLI) is habitually used in transformerless photovoltaic (PV) connected to grid network. But it still has a problem of shoot-through which dwells in its legs, so its operation not reliable. Z source network is employed to permit operation without shoot through risk and improve its reliability. Coupled inductors are replaced the line transformers in to attain lower cost, reduced size, and improved its reliability and efficiency. Coupled inductor which avoids leakage current problem and losses. It employs coupled inductor z source diode clamped three level inverter (CI-Z-DC-TLI) to boost the voltage and further progress the consistency of the proposed system by avoiding the shoot through the problem. The proposed system assures that common-mode voltage and shoot-through risk is avoided. Moreover, controlling DC-TLI with Hysteresis SVM algorithm which improves output voltage and current control. Simulation and experimental results of this proposed system were analyzed using MATLAB environment and FPGA hardware. Keyword:Coupled inductor Z source NPC Diode-clamped three level inverter (DC-TLI) Grid connected system Hysteresis space vector modulation (HSVM) PV System

Hysteresis Control 3-Level SI-NPC Inverter with Wind Energy System

“…The proposed system incorporates Neutral point clamped Topology (Diode-Clamped Topology) [12]. The system is a Voltage Source Inverter as the input voltage level is maintained constant.…”

Wind-PV Hybrid Energy Source Fed Three Level NPC with Quasi Z Source Network

“…They share a common shaft through which mechanical power is transferred to the generator. A Permanent Magnet Synchronous Genertor does not need an excitation field which consideraly reduces energy wastage [9], [10]. It facilitates the wind turbine operation without a gearbox so the operatingcost is reduced.…”

“…In the next figure its equivalent circuit is shown. Applying KVL we get two Equations, (8) (9) Since during shoot through, inverter leg output is zero, Vout is zero. (1), (2), (5), (6) we get two equations each for L1 and L2.…”

“…This is made possible due to the inductor and capacitor arrangement in the QZSI [9]. The output of that inverter leg is zero for this state [9], [10].…”

“…The output of that inverter leg is zero for this state [9], [10]. During shoot through mode all the switches of any leg, individually or in any combination switch on at the same instant giving rise to seven additional shoot through states.…”