Generally, there are two basic powe

Generally, there are two basic power main circuits of
the switching power amplifiers, the monopole (or semibridge
type) and dipole (or full-bridge type). However, the
semi-bridge type is often used in the AMB system because
it is economic and simple. Fig 1 (a) shows the main circuit
of the semi-bridge type. Fig 1 (b) shows a conventional
three-level PWM modulation scheme. Where r U is the
command voltage, 1 G / 2 G is grid driving signal of T1/T2,
Ud is power supply voltage and I is the current in coil respectively