Variable-Speed Hydraulic Pump Control for Flow and Pressure Stability
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Solution Overview
Problem
Conventional fluid pumping systems in industrial applications face inefficiencies due to the inability to precisely control flow and pressure, leading to increased energy consumption and complexity, along with a higher risk of pump cavitation and reduced reliability due to open-loop systems and complex hydraulic circuits.
Innovation Solution
A fluid pumping system incorporating a variable-speed and/or variable-torque pump with two fluid drivers and proportional control valve assemblies, where a controller synchronizes the operation of the prime movers and control valves to precisely control flow and pressure, reducing the need for large fluid reservoirs and minimizing cavitation risk.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If a conventional hydraulic pump runs at full speed or constant speed to ensure adequate pressure, then the system maintains sufficient pressure for flow control devices, but energy consumption increases and the pump does not respond precisely to flow demand changes
Solution Approach 1:
The patent applies dynamics by transitioning from constant-speed pump operation to variable-speed pump operation. The pump speed is dynamically adjusted based on real-time flow demand and pressure requirements, allowing the system to maintain adequate pressure while consuming less energy. The controller continuously monitors system conditions and modulates the pump speed accordingly, rather than running at full speed continuously.
Solution Approach 2:
The patent implements feedback control by using sensors to monitor system pressure and flow conditions, then feeding this information back to the controller. The controller uses this feedback to adjust the pump speed and control valve positions, creating a closed-loop system that optimizes energy consumption while maintaining required pressure levels.
2Measurement precision
If flow control devices are added to precisely control flow in the system, then flow control precision improves, but system complexity increases and additional hydraulic fluid is required
Solution Approach 1:
The patent replaces traditional mechanical hydraulic control systems with an electronically controlled system. Instead of using complex hydraulic control circuits and additional flow control devices, the system uses electronic controllers with sensors and actuators to regulate flow. This substitution reduces system complexity while maintaining or improving flow control precision.
3Reliability
If an open-loop hydraulic system with a large fluid reservoir is used, then the system can maintain fluid temperature and prevent cavitation, but the system complexity increases due to additional connecting components
Solution Approach 1:
The patent extracts or removes the large fluid reservoir from the system by implementing a closed-loop hydraulic system. The hydraulic fluid is recirculated directly from the actuator back to the pump without requiring a large external reservoir. This elimination reduces system complexity while cavitation is prevented through active pressure and flow control.
Solution Approach 2:
The patent uses feedback control to monitor system pressure and flow conditions, adjusting pump operation to prevent cavitation. The controller receives feedback from pressure sensors and flow meters, then modulates pump speed and control valve positions to maintain conditions that prevent cavitation, eliminating the need for a large reservoir.
4Measurement precision
If the pump speed is varied to precisely control flow, then flow control precision improves, but the pump inertia makes it impractical to respond quickly to flow demand changes
Solution Approach 1:
The patent applies preliminary action by pre-positioning control valves and pre-adjusting pump settings based on anticipated flow demands. The system uses predictive control algorithms that anticipate future flow requirements and prepare the system in advance, allowing quick response to flow demand changes while maintaining precision control.
Data Source
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AI summary
A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid-driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid system to a flow set point and a pressure in the fluid system to pressure set point and a concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.