Three-phase six-step motor control circuit

　　The three-phase six-step marine motor application circuit is a circuit connection diagram of an open-loop motor controller with a full-wave six-step drive. The power switch transistor is a Darlington PNP type, and the lower power switch transistor is an N-channel power MOSFET. Since each device contains a parasitic clamp diode, it is possible to return the stator inductive energy to the power supply. The output can drive a delta-connected or star-connected stator, and if a separate power supply is used, it can also drive a neutral-grounded Y-connection.

　　At any given rotor position, there is only one top and bottom power switch (which belongs to a different totem pole) in the circuit. Therefore, both ends of the stator winding can be switched from the power source to the ground by a reasonable configuration, and the current can be bidirectional or full-wave. Because the leading edge spikes usually appear in the current waveform and cause current limiting errors. Therefore, the peak can be suppressed by connecting an Rc filter in series with the current detection input. At the same time, the use of low-inductance resistors in Rs also helps to reduce spikes.