Power systems and methods to improve engine fuel efficiency using an energy storage device
AssigneeIllinois Tool Works Inc.
InventorBrandon Lemke
Life of this patent
Estimating the term…
Abstract
Disclosed example engine-driven power systems include: an engine configured to output mechanical power; a generator configured to convert the mechanical power to first electrical power; an energy storage device configured to be charged using the first electrical power and to discharge stored energy to output second electrical power; and control circuitry configured to: determine a load on the engine and an engine speed; and control charging or discharging of the energy storage device to increase a fuel efficiency of the engine based on a predetermined relationship between the load on the engine, the engine speed, and the fuel consumption of the engine.
Claims15
An engine-driven power system, comprising:
- an engine configured to output mechanical power;
- a generator configured to convert the mechanical power to first electrical power;
- an energy storage device configured to be charged using the first electrical power and to discharge stored energy to output second electrical power;
- a storage device configured to store a brake specific fuel consumption map relating a load on the engine, an engine speed, and fuel consumption of the engine;
- and
- control circuitry configured to:
- determine a load on the engine and an engine speed;
- determine a brake specific fuel consumption value based on the load, the engine speed, and the brake specific fuel consumption map;
- determine a gradient vector at the brake specific fuel consumption value on the brake specific fuel consumption map;
- based on the gradient vector, determine a combination of engine speed change and load change;
- and
- based on the load change, control charging circuitry to charge of the energy storage device to increase a fuel efficiency of the engine by increasing the load or control discharging circuitry to convert energy from the energy storage device to increase a fuel efficiency of the engine by decreasing the load;
- and
- based on the engine speed change, control the engine to change the engine speed.
A method to control an engine-driven power system, comprising:
- outputting mechanical power using an engine;
- converting the mechanical power to first electrical power using a generator;
- accessing, via control circuitry, brake specific fuel consumption map relating a load on the engine, an engine speed, and fuel consumption of the engine;
- determining, via the control circuitry, a load on the engine and an engine speed of the engine;
- determining, via the control circuitry, a brake specific fuel consumption value based on the load, the engine speed, and the brake specific fuel consumption map;
- determining, via the control circuitry, a gradient vector at the brake specific fuel consumption value on the brake specific fuel consumption map;
- based on the gradient vector, determining, via the control circuitry, a combination of engine speed change and load change;
- based on the engine speed change, controlling, via the control circuitry, the engine to change the engine speed;
- and
- based on the load change:
- controlling, via the control circuitry, a charging circuit to convert at least a portion of the first electrical power to charge an energy storage device to increase the load on the engine to increase fuel efficiency of the engine;
- or
- controlling, via the control circuitry, a power conversion circuit to convert second electrical power from the energy storage device to supplement the first electrical power to increase the fuel efficiency of the engine.
Dependencies are inferred from the claim text.