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I would say that voltage gain of 3-phase inverter with Y-connected motor winding is A=0.5*Vdc/Vtm, where: - Vdc - DC bus voltage; - Vtm - voltage command scanning triangular wave amplitude. For Vdc=300V, Vdc=10V A=15. Suppose phase voltage command instantaneous value is v=4V. Then actual phase...

Nobody mentioned so far disbalance that may come from excitation capacitors

When bi-directional energy flow capability is required from power converter, each transistor switch must have an anti-parallel free-wheeling diode.

For H-bridge inductive load, load current should be piecewise linear. Assuming that current probe is good, 4A current peak may be caused by inductance drop due to magnetic saturation for current levels 2A and higher. Reverse recovery current is seen by FET (not by load) at turn-on (not at...

Armature equation: Va=La*(dIa/dt) + Ra*Ia + E; Field winding equation: Vf=Lf*(dIf/dt) + Rf*If; Mechanical equation: J*(d2W/dt2)+D*(dW/dt)=T Motor back EMF: E=Ke*If*W Motor torque: T=Kt*If*Ia There are also shunt, series and compound field winding connections. For permanent magnet DC motor...

Another way to "virtually" disconnect the motor is to run controller with a zero current command. Then controller voltage generated due closed current loop will be exactly compensate for motor back EMF and will drop with motor speed. Motor current all will be PWM current ripple meaning zero on...

Jonaz, if you want I can send you a couple of documents that explain how BLDC motor is commutated and how sensorless BLDC controller works. -Baltic dr_brushless@hotmail.com

1. When selecting IGBT, take about 50% voltage margin - e.g., for 400V maximum DC bus voltage use 600V rated IGBT (this is because of voltage spike at turn-off due to parasitic layout inductance). 2. Take about 50% current margin with respect to amplifier continous current (this assumes typical...