In order to better solve the problem that the tracking speed and steady-state accuracy of photovoltaic MPPT algorithm are difficult to balance

in this papera new variable step size increment conductance method is proposed.This method firstly uses the 0.8 times open circuit voltage method

which can deal with environment mutation

to track quickly to the vicinity of the maximum power point of the photovoltaic cell.Then

the anti-cotangent function variable coefficient method is used to adjust the tracking step size to make the system gradually track to the maximum power point for operation.Such three methods as perturbation method

traditional conductance method and the method presented in this paper are simulated

compared and analyzed under the sudden change of temperature and sunshine intensity.It is shown by the simulation result that the new variable step-size method

compared with the perturbation method and the traditional conductance method

has faster tracking speed and higher steady-state accuracy

which effectively reduces the tracking time and reduces the energy loss due tosteady-state power oscillation.