The transient processes in planar periodic-planar polarization diffraction gratings under influence short bipolar electric pulses are investigated. It is shown that the application of bipolar pulses with certain amplitude and frequency leads to significant increase of diffraction efficiency in non-zero diffraction orders as compared to steady-state diffraction. The dependence of diffraction efficiency of each diffraction order on both the amplitude and frequency of applied pulses is studied. It is shown that the maximum diffraction efficiency of necessary order can be controlled by choosing frequency and amplitude of external pulses. This phenomenon can be used for creation of adaptive polarization diffraction gratings functioning in none-steady state mode.