ETAP Load Flow

Hello,

while running load flow (NR method) with two generaotors, the result doesn't match with hand calculated result. I also tried with matlab. The result from etap is totally different. The problem may be that, during load flow the bus voltage and active power at generator bus are not fixed at prespecified value. The active power is getting zero and voltage is dropping to marginal alert level. I tried using different modes of operation (MVAR control, voltage control, PF control). But, the result is always the same (except MVAR control). How can I overcome this problem?

Thnks in advance.