The characteristic of the torque and power loses are analyzed under the performance of unbalance operation, a current balance control method is brought forward and the experimental results are given.

The mechanism of current-unbalance of 1/2-level is analyzed in detail by simulation. By using current-feedback control, a new PWM control method with the capability of current-balance is proposed.

By calculating two-cylinder diesel's balance and analyzing the problem existed in the current two-cylinder diesel's balance, the improving method is given in the suitable scope.