Generator voltage stabilization system and method
View Patent ↗A generator voltage stabilization system of a heavy-duty vehicle hybrid-electric drive system, which has an engine and a generator coupled with the engine for generating power that varies with rotational speed of the engine, includes one or more circuits having at least one of a DC/DC converter and an DC/AC converter configured to be coupled to the generator, and receive varying power input from the generator and provide stabilized voltage output power; and a control computer coupled to the one or more circuits to control the one or more circuits to provide stabilized voltage output power with varying power input from the generator.
1. A system for operating a heavy-duty vehicle hybrid-electric drive system of a heavy-duty vehicle over 10,000 pounds GVWR, the heavy-duty vehicle hybrid-electric drive system including an engine configured to provide a rotating output, the system comprising:
a generator mechanically coupled to the engine, the generator configured to generate an AC power having a variable AC voltage that varies with rotational speed of the engine rotating output;
a rectifier electrically coupled to the generator, the rectifier configured to rectify the generated AC power, and further configured to output a first DC power having a variable DC voltage that varies with rotational speed of the engine rotating output;
a DC/DC converter electrically coupled to the rectifier, the DC/DC converter configured to receive the first DC power, and further configured to output a second DC power;
a controller configured to control the DC/DC converter such that the second DC power outputted from the DC/DC converter is outputted having a stabilized DC voltage that does not vary with rotational speed of the engine;
a DC/AC inverter electrically coupled to the DC/DC converter, the DC/AC inverter configured to invert the second DC power and output an AC power having a stabilized AC voltage that does not vary with rotational speed of the engine; and,
an electric motor electrically coupled to the DC/AC inverter and mechanically coupled to at least one drive wheel of the heavy-duty vehicle, the electric motor configured to be driven using the AC power having the stabilized AC voltage,
wherein the generator is further configured to generate three-phase AC power;
wherein the rectifier is further configured to rectify the generated three-phase AC power;
wherein the DC/AC inverter comprises three phases of a four-phase IGBT inverter;
wherein the electric motor comprises a three-phase electric motor and is electrically coupled to the three phases of the four-phase IGBT inverter;
wherein the DC/DC converter comprises a reactive inductor and an IGBT solid state high power switching circuit in a choppered configuration, and,
wherein the IGBT solid state high power switching circuit comprises a fourth phase of the four-phase IGBT inverter.
2. The system of claim 1 , wherein the engine is further configured to provide a variable rotating output in response to load power demands, and to operate at an optimum efficiency.
3. The system of claim 1 , wherein the rectifier comprises one or more multiple-diode rectifiers.
4. The system of claim 1 , wherein the controller is configured to provide an output power having a stabilized voltage, that does not vary with rotational speed of the engine, to drive at least one of the following vehicle accessories: an air conditioner, a hydraulic pump, an air compressor, one or more fans, one or more blowers, a water pump, an oil pump, a fuel pump, a vacuum pump, and an electric hydraulic actuator.
5. The system of claim 1 , wherein the controller is configured to provide an output power having a stabilized voltage, that does not vary with rotational speed of the engine, to charge an energy storage device.
6. The system of claim 1 , wherein the generator is further configured to generate multiple-phase AC power; and,
wherein the rectifier is further configured to rectify the generated multiple-phase AC power.
7. The system of claim 1 , wherein the generator is further configured to generate three-phase AC power; and,
wherein the rectifier is further configured to rectify the generated three-phase AC power.
8. A method for operating a heavy-duty vehicle hybrid-electric drive system of a heavy-duty vehicle over 10,000 pounds GVWR, the heavy-duty vehicle hybrid-electric drive system including an engine configured to provide a rotating output and a generator mechanically coupled to the engine, the method comprising:
generating an AC power via the generator, the AC power having a variable AC voltage that varies with rotational speed of the engine rotating output;
rectifying the generated AC power via a rectifier;
outputting a first DC power from the rectifier, the first DC power having a variable DC voltage that varies with rotational speed of the engine rotating output;
receiving the first DC power into a DC/DC converter electrically coupled to the rectifier;
outputting a second DC power from the DC/DC converter;
controlling the DC/DC converter via a controller, such that the second DC power is outputted having a stabilized DC voltage that does not vary with rotational speed of the engine;
inverting the second DC power through a DC/AC inverter electrically coupled to the DC/DC converter;
outputting an AC power having a stabilized AC voltage, that does not vary with rotational speed of the engine, from the DC/AC inverter; and,
driving an electric motor electrically coupled to the DC/AC inverter and mechanically coupled to at least one drive wheel of the heavy-duty vehicle using the stabilized AC voltage;
wherein the generator is further configured to generate three-phase AC power;
wherein the rectifier is further configured to rectify the generated three-phase AC power;
wherein the DC/AC inverter comprises three phases of a four-phase IGBT inverter;
wherein the electric motor comprises a three-phase electric motor and is electrically coupled to the three phases of the four-phase IGBT inverter;
wherein the DC/DC converter comprises a reactive inductor and an IGBT solid state high power switching circuit in a choppered configuration, and,
wherein the IGBT solid state high power switching circuit comprises a fourth phase of the four-phase IGBT inverter.
9. The method of claim 8 , wherein the engine is further configured to provide a variable rotating output in response to load power demands, and to operate at an optimum efficiency.
10. The method of claim 8 , wherein the rectifier comprises one or more multiple-diode rectifiers.
11. The method of claim 8 , wherein the controller is configured to provide an output power having a stabilized voltage, that does not vary with rotational speed of the engine, to drive at least one of the following vehicle accessories: an air conditioner, a hydraulic pump, an air compressor, one or more fans, one or more blowers, a water pump, an oil pump, a fuel pump, a vacuum pump, and an electric hydraulic actuator.
12. The method of claim 8 , wherein the controller is configured to provide an output power having a stabilized voltage, that does not vary with rotational speed of the engine, to charge an energy storage device.
13. The method of claim 8 , wherein the generator is further configured to generate multiple-phase AC power; and,
wherein the rectifier is further configured to rectify the generated multiple-phase AC power.
14. The method of claim 8 , wherein the generator is further configured to generate three-phase AC power; and,
wherein the rectifier is further configured to rectify the generated three-phase AC power.