基于转矩控制的变转速定量泵的运行特性研究

Operating Characteristics of Variable Speed Fixed Pump Based on Torque Control

采用变转速电机驱动定量泵作为电液动力源时,通过控制转速来实现压力控制,难以适应负载流量快速变化的工况。而采用伺服电机通过直接转矩控制的方法驱动定量泵实现压力控制,与变转速控制压力相比,具有动态响应更快的优点。但受转速等非线性因素影响,使得转矩与压力具有非线性对应关系,在开环控制时,压力控制偏差较大。为此,在开环控制压力时,采用可以迭代离线生成的转速、压力控制偏差二维图表来进行转速补偿。通过理论分析与数字仿真进行研究,结果表明,在相同条件下,与用拟合曲线进行转速补偿的压力控制方案相比,该方案的压力控制误差降低为2%,可以更好的实现压力控制。

When using a variable speed motor to drive a fixed pump as an electro-hydraulic power source,pressure control is achieved by controlling the speed,which is difficult to adapt to the rapidly changing load flow conditions.Using a servo motor to drive a fixed pump through direct torque control to achieve pressure control has the advantage of faster dynamic response compared to variable speed pressure control.However,due to the influence of nonlinear factors such as rotational speed,there is a non-linear correspondence between torque and pressure,which leads to significant pressure control deviation in open-loop control.Therefore,this research proposes to use a 2D chart of speed and pressure control deviation that can be iteratively generated offline for speed compensation in open-loop pressure control.Through theoretical analysis and digital simulation,the results show that under the same conditions,compared with the pressure control scheme using fitted curves for speed compensation,the pressure control error is reduced to 2%.This scheme can better achieve pressure control.