Hoist resistance inductive load current control system features: resistance inductive load, L value is large, id waveform substantially flat. α≤30 °, the rectified voltage waveform with the same load resistance. α> 30 ° when, u2 zero crossing, VT1 is not turned off until the arrival of VT2 pulse before commutation by VT2 turn leads to power the load, while applying back pressure it off -ud waveform to VT1 negative part.
id waveform has some ripple, but to simplify the analysis and quantitative calculation, id can be approximated as a horizontal line. Resistive load shifting sense of phase range of 90 °.
Full-controlled three-phase bridge rectifier circuit: is the most widely used three-phase bridge rectifier circuit, common cathode Group: cathodes connected together three thyristors (VT1, VT3, VT5); common anode group: an anode connected together 3 thyristors (VT4, VT6, VT2); conduction order: VT1 → VT2 → VT3 → VT4 → VT5 → VT6
When natural commutation, every time two thyristor of the AC voltage corresponding to the maximum value of a cathode and anode connected to the connected AC voltage value of the minimum one.
Resistive load: Suppose the circuit for thyristor diode, thyristor firing angle is equivalent to a = 0 °. AC voltage is turned up a group of three common cathode thyristor anode connection. Group of three common anode thyristor, the cathode connected to an AC voltage of a value of the minimum conduction. Any time set common anode and common cathode thyristor group and one each in the conduction state, the voltage applied to the load on the line for a voltage.