General Electric Company

Ronald F Griebel

Ajith Kuttannair Kumar

Warren F Bessler

Gregory Alan Marsh

Ronald B Bailey

Herbert J Brown

Dean S Grinch

Stuart W McElhenny

A method and apparatus for cranking of an internal combustion engine in an AC electric traction motor propelled vehicle using inverters normally coupled to supply power to each of a plurality of AC motors. The inverters have DC input terminals connected between a relatively positive DC bus and a relatively negative DC bus and the DC buses are connected to DC output terminals of a rectifier. The rectifier has AC input terminals connected to stator terminals of a synchronous generator. The generator includes a field winding and a rotor connected in driving relationship to a crank shaft of the engine. The vehicle further includes switching apparatus for selectively connecting a battery to the positive and negative DC buses and for disconnecting at least one of the inverters from the AC motor and connecting the at least one of the inverters to supply power to the generator such that the at least one of the inverters is operable to energize the generator whereby the generator operates in a motoring mode to rotate the engine crank shaft to start the engine. Another of the inverters is separately connectable to a pre-lube pump motor for effecting lubrication of the engine prior to starting the engine. After lubricating and starting of the engine, the switch reconnects the inverters to supply AC electric power to respective traction motors of the vehicle.

Use of traction inverter for supplying power for non-traction

In a tunnel control system for traction vehicles, the normal deration function is suppressed to delay deration in a tunnel. The traction vehicle is provided with a controller having a normal operation mode and a tunnel operation mode. A tunnel indicator connected to the controller provides an indication of when the vehicle is approaching a tunnel and causes the controller to switch into the tunnel operation mode. In this mode, the controller increases cooling to reduce the temperature of the vehicle's prime mover and the control electronics prior to entering the tunnel. As the traction vehicle enters the tunnel, the controller monitors the engine oil temperature and the ambient air temperature. If the ambient air temperature exceeds a predetermined value, then the cooling of the control electronics is discontinued. If the oil temperature exceeds a threshold (which is about 10.degree. C. higher than the normal deration threshold), then power to the prime mover is derated. After the vehicle exits the tunnel, the prime mover and control electronics are gradually cooled to avoid thermal shock.

Tunnel operation for self-propelled traction vehicles

In an electrical propulsion system on board a moving traction vehicle (such as a rapid transit rail car) having current collectors in contact with an energized third rail, controllable switch means is used to connect the system to the current collectors. From time to time the current collectors traverse gaps between adjacent sections of the third rail, in which event regenerative braking operation of the system will be prevented unless the next third rail section is energized by a wayside source of voltage. The switch means comprises the parallel combination of a diode that conducts current when the system is operating in a motoring mode and a reversely-poled thyristor that conducts regenerative braking current once a firing signal is applied thereto. To detect the energized status of the third rail, an electrical filter network is excited by the third rail voltage and derives an output value representative of the amplitude of an a-c ripple component of such voltage having a fundamental frequency that characterizes the wayside voltage source, and after each third rail gap is traversed a firing signal is applied to the thyristor as soon as this value exceeds a predetermined minimum level.

Regenerative braking protection for an electrically-propelled traction

A plurality of high power semiconductor devices are connected in circuit with at least one electric traction motor for controlling electric power to the motor. The semiconductor devices are each thermally connected between a pair of generally hollow heat sinks adapted for passing cooling air therethrough for extracting heat therefrom. An anode terminal of the devices is coupled to one of the heat sinks of a pair and a cathode terminal of the devices is connected to the other heat sink of the pair. Each of the heat sinks are mounted in a cantilever fashion to a common air plenum forming one wall of an electrical circuit area of a vehicle. The distal ends of the heat sinks of a pair are coupled together by an air flow conduit thus forming a continuous air passage through the pair of heat sinks which begins and ends at the surface containing the air supply plenum. One end of one of the pair of heat sinks, preferably the heat sink coupled to the cathode terminal, is connected to an exhaust conduit. Cooling air is then directed into the end of the other heat sink, circulating through the one heat sink and out through the exhaust conduit. In this manner, the cooling air is held in a closed path extending into the electrical circuit area so that contaminants are not deposited on the electrical components.

High power AC traction inverter cooling

An improved auto-sequential commutated controlled current inverter for driving a multi-phase load from a source of controlled magnitude direct current is disclosed. The auto-sequential commutated inverter comprises a plurality of parallel connected branch sub-circuits with each branch sub-circuit comprising at least one gate controlled power thyristor device connected in series circuit relationship with a respective power diode. The branch sub-circuits thus comprised are connected between a respective phase input to the multi-phase load and a common direct current power supply terminal for connection to the source of controlled magnitude direct current. A respective commutating capacitor is interconnected between the junctures of the power thyristor and power diode of each respective branch sub-circuit and the power thyristor and power diode of the next adjacent branch sub-circuit. An improved reset circuit is connected to the auto-sequential commutated inverter thus constructed for improving the frequency response characteristics of the inverter, thereby, allowing it to operate at higher frequencies with minimum size power components. The improved reset circuit comprises a common impedance for assisting in the discharge of energy stored in the commutating capacitors. The common impedance has one terminal connected to the common direct current power supply terminal and the remaining terminal connected in common to corresponding terminals of a plurality of coupling diodes. There is one coupling diode for each phase of a multi-phase load being supplied with each coupling diode having one terminal connected in common with the corresponding terminals of the remaining coupling diodes to the said one terminal of the common impedance. The remaining terminals of the respective coupling diodes are connected respectively to the juncture of the power thyristor and power diode of a respective branch sub-circuit. The common impedance preferably comprises a common inductive reactance having resistance for dissipating energy stored in the common inductive reactance and further preferably comprises a discrete inductor having an inductive reactance which series resonates with the equivalent capacitance of the commutating capacitors at a higher frequency than the desired operating frequency of the inverter. The dissipating resistance may be in the form of a discrete resistor connected either in series or in parallel with the discrete inductor. Other embodiments of the reset circuit are described.

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Erie, PA, United States of America

Ronald F Griebel