Application of error least mean square（LMS）method in voltage testing of power smart sensor is exploited.Several ways to obtain voltage RMB and initial phase angle

which are important power parameters but difficult to test in power smart sensor

are proposed

analyzed and compared.It is pointed out that when error LMS method is applied

the performance requirement can be declined and results in system simplified and cost reduced.Simulation results show that sample frequency and ratio of signal to noise are required very high to got power parameters according to their definition directly

however

if error LMS method is applied

the sample frequency can be declined triple when obtaining voltage RMB

and noise amplitude can be permitted from less 5% to 15% of signal amplitude when working out the initial phase angle.