Polarity reversal output-type inverter with power decoupling and control method thereof

Abstract

The invention discloses a polarity reversal output-type inverter with power decoupling and a control method thereof. The main circuit topology of the inverter comprises a DC power supply, an input capacitor, a primary-side switch transistor, an isolation transformer, a cut-off diode, a filter capacitor, a polarity reversal inverter bridge, an output filter circuit, a power grid and a decoupling circuit. The control method comprises steps: a unit sinusoidal wave is acquired through a PLL from a power grid voltage sampling value, the maximum DC input power is acquired through an MPPT from inputvoltage and current sampling values, a voltage disturbance signal is acquired through a voltage loop from a decoupling capacitor voltage sampling value, five modulation wave signals are obtained through a current reference operation circuit and a modulation signal generating circuit, and finally, through a PWM control circuit and a logic circuit, a grid-connected inverter is controlled to work. Adecoupling circuit formed by a decoupling switch transistor, a decoupling diode and a decoupling capacitor is added to the primary side of the isolation transformer, secondary current ripples at the DC power supply input side are effectively eliminated, and grid connection is realized.

Description

technical field [0001] The invention relates to a polarity inversion output type inverter with power decoupling and its control method, which belongs to the miniature and grid-connected inverter, which uses an added decoupling circuit to eliminate the secondary current ripple on the DC input side . Background technique [0002] In recent years, energy shortage and environmental pollution have attracted widespread attention. New energy sources such as photovoltaics and fuel cells have developed rapidly due to their clean, efficient, and sustainable advantages, such as new energy power generation systems. For this kind of new energy power generation system, the output power of the grid-connected inverter contains a power ripple that is twice the frequency of the grid voltage. As far as components are concerned, it will affect their maximum power point tracking and reduce system efficiency. Therefore, it is of great significance to solve the secondary current ripple problem in...

AI Technical Summary

Problems solved by technology

All in all, these methods of filtering secondary current ripple through passive devices have problems such as large size, low reliability, and unstable filtering performance.

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