  This letter proposes a predictor-corrector method to strike a balance between
simulation accuracy and efficiency by appropriately tuning the numerical
integration step length of a power system time-domain simulation. Numerical
tests indicate that, by estimating the truncation error for step length tuning
based on the 2-Step Adams-Moulton method and the implicit Trapezoidal method,
the proposed method can provide much more precise results at little cost of
efficiency compared to a conventional variable step method based on Newton's
method.
