Hydraulic Charging System with Electronic Power Limiting And Load Balancing

A hydraulic charging system comprising:

• two or more power sources;
• two or more electric motors;
• two or more current sensors;
• two or more variable displacement hydraulic (VDH) pump;
• two or more pressure control valves;
• at least one hydraulic fluid accumulator;
• a pressure sensor;
• and
• a closed loop logic controller comprising multiple control algorithms to balance the loading of two or more electric motors;
• wherein the two or more power sources provide power to the two or more electric motors,
• wherein the two or more electric motors drive the two or more (VDH) pumps, the two or more current sensors monitor the load draw of the two or more motors during operation, and
• the two or more VDH Pumps;
• pressurize a hydraulic fluid until it reaches a setpoint of each of the two or more pressure control valves, and
• charges the at least one hydraulic accumulator;
• wherein the system hydraulic fluid pressure is monitored by the pressure sensor,
• wherein the two or more current sensors and the pressure sensor provide feedback readings to the closed loop logic controller, and
• wherein the multiple control algorithms of the closed loop logic controller processes readings from the two or more current sensor and the reading from the pressure sensor to generate commands to the two or more pressure control valves to maintain desired constant loading conditions of the two or more variable displacement hydraulic (VDH) pumps and constant loading conditions the two or more electric motors.

A method of reducing cyclic loading in a hydraulic system comprising:

• providing at least one electric motor;
• providing at least one current sensor;
• providing at least one pressure compensated, variable displacement (VDH) pump;
• providing at least one pressure control valve;
• providing at least one hydraulic fluid accumulator;
• providing a pressure sensor;
• and
• providing a closed loop logic controller comprising multiple control algorithms;
• wherein the at least one power source provides power to the at least one electric motor to drive the at least one (VDH) pump, which charges the hydraulic accumulator and pressurize a hydraulic fluid until it reaches a setpoint of the at least one electronic pressure control valve,
• wherein the at least one current sensor monitors the load draw of the at least one motor during operation and the system hydraulic fluid pressure is monitored by the pressure sensor,
• wherein the at least one current sensor and the pressure sensor provide feedback readings to the multiple algorithms of the closed loop logic controller, and the multiple algorithms of the closed loop logic controller process the at least one current sensor reading and the pressure sensor reading in order to generate commands to the at least one pressure control valve to reduce cyclic load spikes in the loading conditions of the at least one variable displacement hydraulic (VDH) pump and the at least one electric motor.

A closed loop logic controller for controlling a hydraulic charging system having multiple control algorithms comprising;

• a pressure control loop;
• a power limiting control loop;
• and
• a high speed load control loop;
• wherein the pressure control loop receives an average pressure reading from an electronic pressure sensor located after an upstream pressure compensated variable displacement hydraulic (VDH) pump and at least one accumulator and compares said pressure reading to a pressure setpoint to generate a first control point,
• wherein the power limiting control loop receives a load reading from an electronic current sensor located between a power source and an electric motor driving said (VDH) pump and compares said load reading to a load limiting setpoint and generates a second control point,
• wherein said pressure control loop forwards the first control point and said power limiting control loop forwards the second control point to a high-speed load control loop;
• and
• wherein the high speed load control loop controls the first control point in a high speed manor and utilizes the second control point as a limiting value to regulate pressure of a hydraulic fluid from the at least one hydraulic accumulator, to control the load of the system by sending an output signal to a pressure control valve to increase or decrease pressure appropriately by sending an output signal to a pressure control valve to increase or decrease flow appropriately, thereby also maintaining the average load of a corresponding motor.

A method of controlling a hydraulic charging system comprising:

• providing a closed loop logic controller comprising multiple control algorithms;
• wherein a pressure control loop:
• receives an average pressure reading from an electronic pressure sensor located after an upstream pressure compensated variable displacement hydraulic (VDH) pump and at least one hydraulic accumulator;
• compares said pressure reading to a pressure setpoint to generate a first control point;
• wherein a power limiting control loop:
• receives a load reading from an electronic current sensor located between a power source and an electric motor driving said VDH pump;
• compares said load reading to a load limiting setpoint and generates a second control point;
• wherein said pressure control loop forwards the first control point and said power limiting control loop forwards the second control point to a high-speed load control loop;
• and
• wherein said high speed load control loop controls the first control point in a high speed manner and utilizes the second control point as a limiting value to regulate pressure of a hydraulic fluid from the at least one hydraulic accumulator to control the load of the system by sending an output signal to a pressure control valve to increase or decrease pressure appropriately, thereby also balancing the load of a corresponding motor.

A closed loop logic controller for controlling a hydraulic charging system having multiple control algorithms comprising;

• a pressure control loop;
• a load balancing control loop;
• a current sensor selector;
• a power limiting control loop;
• and
• a high-speed load control loop;
• wherein the pressure control loop receives an average pressure reading from an electronic pressure sensor located after a plurality of upstream pressure compensated variable displacement hydraulic (VDH) pumps and at least one accumulator and compares said pressure reading to a pressure setpoint to generate a first control point,
• wherein a load balancing control loop and a current sensor selector each receive a load signal from two or more current sensors;
• wherein the current sensor selector selects the highest current in the system and sends that signal to the power limiting control loop and the load control loop;
• wherein the power limiting control loop:
• receives the highest load signal from the current sensors of the at least two current sensors and the limit of the output for the high-speed load control loop,
• wherein the high-speed load control loop maintains the system load, reduces the power fluctuations on the electrical system, and is limited by the power limiting control loop,
• wherein the load control loop transmits a signal to one of the pressure control valves and a load balancing incorporation control,
• wherein the load balancing incorporation module receives the output signal value of the load balancing control loop and the output signal value of the load control loop to cause the load of the two or more motors to run at the same load and sends a corresponding balanced signal to the plurality of pressure control valves.

A method of controlling a hydraulic charging system comprising:

• providing a closed loop logic controller comprising multiple control algorithms;
• wherein a pressure control loop:
• receives a pressure reading from an electronic pressure sensor located after a plurality of upstream pressure compensated variable displacement hydraulic pumps and at least one hydraulic accumulator;
• compares said pressure reading to a pressure setpoint to generate a first control point;
• wherein a first current sensor of at least two current sensors located between a first power source of a plurality of power sources and a first upstream electric motor of a plurality of electric motors driving one of said plurality of upstream pressure compensated variable displacement hydraulic pumps and a second current sensor of the at least two current sensors located between a second power source of the plurality of power sources and a second upstream electric motor of the plurality of electric motors driving one of said plurality of upstream pressure compensated variable displacement hydraulic pumps, each send a load signal to a load balancing control loop and a current sensor selector;
• wherein a power limiting control loop:
• receives the highest load signal from the first current sensor of the at least two current sensors and the limit of an output for the load control loop,
• wherein the load control loop maintains the system load, reduces the power fluctuations on the electrical system, and is limited by the power limiting control loop,
• wherein a signal from the load control loop is sent out to one of the pressure control valves and a load balancing incorporation , and
• wherein the load balancing incorporation module takes the output signal value of the load balancing control loop and the output signal value of the load control loop to cause the load of the two or more motors to run at the same load and sends a corresponding balanced signal to the plurality of pressure control valves.

A method for controlling a load in hydraulic charging system, the method being executed by one or more processors and comprising:

• receiving a pressure reading from an electronic pressure sensor;
• determining a first control point based on a comparison of said pressure reading to a pressure setpoint;
• receiving a load reading from an electronic current sensor;
• determining a second control point based on a comparison of said load reading to a load limiting setpoint;
• controlling said first control point in a high-speed manner, and
• regulating pressure of a hydraulic fluid from an at least one hydraulic accumulator to control the load of the hydraulic charging system by employing said second control point as a limiting value.