ABB Sensorless pumping for the ACH580 ACQ580 应用说明文档(英语).pdf

— Technical Note 131 Sensorless pumping for the ACH580/ACQ580 Pressure control Introduction The ACH580 and ACQ580 drives can perform internal flow calculations that allow for controlling the pump speed to match the system load requirements without the use of external feedback sensors. A sensorless flow calculation function uses the pump data to calculate the flow in the system based on measured flow, pressure, and power. By testing the pump and motor combinations, system accuracy is increased by reducing the data tolerance issues created by individual component testing. The PQ (Power to Flow) data is used to calculate the flow, and the calculated flow is then used in the QH (Flow to Head) data to determine the head of the system. The required information needed to set up the PQ and QH sensorless pump control is the system power, flow, and head. By using up to 10 data points through no flow to full flow conditions, the drive can calculate the flow to head and head to flow without the use of external sensors. This technical note is to assist an OEM in setting up and testing the “ PQ and QH” (power to flow and flow to head) function of the ACH580/ACQ580 drive with drive firmware version of 2.18.2.1 or higher. Factors influencing the accuracy of the system By testing the pump/motor combination, more accurate data is obtained. The accuracy of the test data acquired is reflected in the accuracy of the drives mathematical prediction, allowing for better performance in sensorless pump control modes. Drive motor control modes: • Scalar control: Scalar control sets a specific V/Hz according to the data given on the motor nameplate. The actual slip of an asynchronous motor will be dependent on the pump load compared to the motors capabilities. When a motor and pump are tested as a unit, the actual slip is part of the results. • Vector control: Vector control uses