Control system for an electric locomotive having AC to DC converters

A control system for an electric locomotive, having two cascaded power converters, one of said converters having a capacitance connectable thereto, comprising:

• two firing signal generators responding to an electric current supplied to said converters by generating firing signals, each of the firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with phase control angles of said two firing signal generators being different;
• and
• means responsive to a magnitude of a psophometric disturbing current component included in the current supplied to said converters, and changing the firing signals to be supplied to said two converters when a first condition that the magnitude of the psophometric disturbing current exceeds a predetermined value is satisfied, whereby the phase control angle of the firing signal supplied to the one of said converters to which the capacitance is connectable is made greater than that supplied to the other converter.

A system for an electric locomotive having two cascaded power converters, a first capacitance connected to one of said converters and a second capacitance connected to the other one of said converters, the first capacitance being larger than the second capacitance, comprising:

• two firing signal generators responding to an electric current supplied to said converters by generating firing signals, each of the firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with phase control angles of said two firing signal generators being different;
• and
• means responsive to a signal related to a speed of the locomotive for changing the firing signals to be supplied to said two converters when a first condition that the speed-related signal exceeds a predetermined value is satisfied, whereby the phase control angle of the firing signal supplied to the one of said converters to which the capacitance is connectable is made greater than that supplied to the other converter.

A control system for an electric locomotive, having two cascaded power converters, a first capacitance connected to one of said converters and a second capacitance connected to the other converter, the first capacitance being larger than the second one, comprising:

• two firing signal generators responding to an electric current supplied to said converters by generating firing signals, each of the firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with phase control angles of said two firing signal generators being different;
• and
• means responsive to a magnitude of a psophometric disturbing current component included in the current supplied to said converters, and changing the firing signals to be supplied to said two converters when a first condition that the magnitude of the psophometric disturbing current component exceeds a predetermined value is satisfied, whereby the phase control angle of the firing signal supplied to the one of said converters to which the capacitance is connectable is made greater than that supplied to the other converter.

A control system for an electric locomotive, having two power converters, which are also operable as inverters, one of said converters having a capacitance connectable thereto, comprising:

• two firing signal generators responding to an electric current flowing to the converters by generating firing signals, each of said firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with the phase control angles of said two firing signal generators being different;
• and
• means responsive to two signals related to a speed of the locomotive, for changing said two firing signals to be supplied to said two converters when a first condition with one of the speed-related signals exceeding a predetermined valve is satisfied during a powered operation of said converters or when a second condition that the other speed-related signal is lower than a predetermined value is satisfied during a regeneration operation of said converters whereby the phase control angle of said firing signal supplied to one of said converters to which a capacitance is connectable is made greater than the phase control angle of the other one of said firing signals supplied to the said other one of said converters.

A control system for an electric locomotive, having two cascaded power converters, which are also operable as inverters, one of the said converters having a capacitance connectable thereto, comprising:

• two firing signal generators responding to an electric current flowing through said converters by generating firing signals, each of the firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with phase control angles of said two firing signal generators being different;
• and
• means responsive to a magnitude of a psophometric disturbing current component including in the current flowing through said converters, for changing the firing signals to be supplied to said two converters when the magnitude of the psophometric current psophometric current component exceeds a predetermined value, whereby the phase control angle of the firing signal supplied to the one of said converters to which the capacitance is connectable is made greater than that supplied to the other converter.

A method for controlling an electric locomotive having two cascaded power converters and a capacitance connected to one of said converters, comprising:

• providing firing signals from two firing signal generators, each of the firing signals being supplied to cause operation of different ones of said converters in a predetermined order, with phase control angles of said two firing signal generators being different;
• and
• changing the firing signals to be supplied to said two converters when a signal related to a speed of the locomotive exceeds a predetermined value, whereby the phase control angle of the firing signal supplied to the one of said converters to which a capacitance is connectable is made greater than that supplied to the other converter.

A control system for an AC electric locomotive according to claim 22, wherein said switching means is adapted to respond to harmonic currents contained in an AC input current after the magnitude of the harmonic currents have reached a predetermined value.

A control system for an AC electric locomotive according to claim 28, wherein said power factor control means is removably connectable across the AC input terminals and is adapted to be connected to the AC input terminals in response to a predetermined status of the AC electric locomotive.