Control locations and operating modes 23 Speed control modeThe motor follows a speed reference given to the drive. This mode can be used eitherwith estimated speed as feedback, or with an encoder or resolver for better speedcontrol accuracy.Speed control mode is available in both local and external control. It is also availableboth in DTC (Direct Torque Control) and scalar motor control modes. Torque control modeMotor torque follows a torque reference given to the drive. Torque control is possiblewithout feedback, but is much more dynamic and accurate when used in conjunctionwith a feedback device such as an encoder or a resolver. It is recommended that afeedback device is used in crane, winch or lift control situations.Torque control mode is available in DTC motor control mode for both local andexternal control locations. Frequency control modeThe motor follows a frequency reference given to the drive. Frequency control is onlyavailable in scalar motor control mode. DC voltage control modeThis mode is intended especially for off-grid applications where the inverter unit isconnected to a generator and the supply unit creates an AC supply network.The inverter unit adjusts the DC voltage by controlling generator torque. Based on theDC circuit capacitance either from an internal database or user input parameter, andmeasured DC voltage, the PI controller outputs a power reference. The powerreference is then converted to a torque reference.The settings of the DC voltage control chain are available in parameter group 29Voltage reference chain.DC voltage control mode is only available with drives with a BCU control unit. Special control modesIn addition to the control modes mentioned above, the following special controlmodes are available:• Process PID control. For more information, see section Process PID control (page66).• Emergency stop modes Off1 and Off3: Drive stops along the defined decelerationramp and drive modulation stops.• Jogging mode: Drive starts and accelerates to the defined speed when thejogging signal is activated. For more information, see section Jogging (page 55).ghv Vertriebs-GmbH | Am Schammacher Feld 47 | 85567 Grafing | Telefon + 49 80 92 81 89 0 | info@ghv.de | www.ghv.de
