Key Technology Research On Three Phase Photovoltaic Grid-connected Inverter

With the exhaustion of Coal, oil, natural gas on the earth, mankind will soon faceconditions of no available energy, so looking for a green alternative energy becomes theurgent task of human society. At present, the usage of solar energy is the most feasible.Solar energy has many advantages such as widespread, limitless reserve and so on. Solarenergy becomes the main form in the new energy utilization. There are many kinds ofsolar energy utilization ways, such as solar water heater, solar thermal, solar photovoltaicpower generation, etc. Solar photovoltaic power generation is currently a major way.Three-phase photovoltaic (pv) grid inverter is the critical equipment in thephotovoltaic power generation system. This article focuses on the key technology ofthree-phase photovoltaic (pv) grid inverter, including the design of main circuit, outputcurrent sinusoidal PWM control technology, maximum power point tracking, and islanddetection technology in the system, Current Circulation suppression algorithmtechnology.The design of main circuit mainly introduces how to select the parameter ofinductance in AC side and capacitor in DC side. They are all the critical components ofthe three-phase AC photovoltaic inverter. Elaborate the MPPT(Maximum power pointtracking)methods, including the constant voltage method, mountain climbing, admittanceincrement method, and putting forward an improved tracking method. it is said theconstant voltage-perturbation method. Islanding detection method contains the passivedetection and active island detection, and introduces a simple island detection method-sliding frequency deviation method. Current Circulation suppression algorithm is akind of control method, space zero vector.