DIODE CLAMPLED MULTIPLE LEVEL INVERTER WITH 3 LEVEL OUTPUT
ABSTARCT :
The elementary concept of a multilevel converter is to achieve high power by using a series of a power semiconductor switches with lower voltage D.C source. The output voltage waveform of a multi-level inverter is composed of the number of levels of voltages, typically obtained from capacitor voltage sources. In this paper, single phase diode clamp multilevel inverter topology is analyzed by employing SPWM technique which controls the switching operation. Circuit configuration and theoretical operation are also discussed. The performance of the topology is investigated through MATLAB based simulation results.
EXISTING SYSTEM :
? The performance of the proposed algorithm in terms of low THD values in comparison with other existing PWM techniques.
? In this work, VLSI architecture for phase disposition PWM control was developed and tested in real time by connecting with induction motor.
? Speed control characteristics of the induction motor were performed.
? The performance of the proposed circuit was evaluated using THD, voltage stress and settling time.
? Multilevel inverters are capable of operating at high switching frequencies and capable of producing a low level harmonics. Multilevel converters generate a lower common mode voltage.
DISADVANTAGE :
? Different voltage ratings for clamping diodes are required.
? Real power flow is difficult because of the capacitors imbalance.
? Need high voltage rating diodes to block the reverse voltages.
? The number of switches, capacitors, and diodes required in the circuit increases with the increase in the number of output voltage levels. Extra clamping diodes required are 12nn per phase.
PROPOSED SYSTEM :
• This paper proposes a switching table based three level diode clamped multilevel inverter (DCMLI).
• The proposed control method determines the sector and the voltage vector are selected from switching table.
• It is used to generate gating signals for the inverter.
• When the diode-clamped multilevel inverter, the capacitor clamped (or flying capacitor) multilevel inverter, and the cascade multilevel inverter were proposed.
• The significant feature of the proposed method is its simplicity.
ADVANTAGE :
? A large number of levels ‘n’yields a small harmonic distortion.
? All of the phases share a common dc bus.
? Reactive power flow can be controlled.
? High efficiency for fundamental switching frequency.
? Relatively simple control methods.
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