Siemens Automation and Drives is now adding the PM250 and PM260 regenerative power modules to its Sinamics G120 range of frequency inverters, which return current obtained from the regenerative operation of drives to the power network.
Machines place specific demands regarding motors and generators on the drives used with them. The braking energy can either be thermally converted by means of resistors or returned to the power supply network via regenerative units.
Regeneration of energy saves costs normally incurred for additional cooling, heat removal and braking choppers, as well as requiring less installation space. Savings can also be made in the planning of braking resistors and commutating reactors and in the area of energy consumption. The Sinamics G120 inverter series now features regenerative power modules in the form of the PM250 and the PM260.
With a nominal voltage of 400 V, the PM250 in frame sizes C to F handles outputs from 5.5 to 75 kW. The power module can also be used for STO, SS1, SLS and SBC safety applications. The PM260, for supply voltages of 690 V, is available in frame size D for 15 kW with or without a class A input filter. The integrated LC output filter ensures a clean sinusoidal current at the inverter output and enables cable lengths of up to 300m.
In addition, the bearing current is lower, thanks to the output filter that reduces wear on the motor and allows the use of motors with less winding insulation. The standard switch frequency of 16 kHz ensures low-noise operation with a high level of efficiency and low heat generation. An additional feature of the PM260 is its innovative Sic semiconductor technology that ensures that, although having the same power output, the inverter is more compact than comparable standard converters with an optional LC filter. Moreover, the PM260 power module can be used for STO, SS1, SLS and SBC safety applications.
This innovative method of power regeneration is characterised by low harmonics, input currents and wiring cross-sections. As regenerative power modules, the PM250 and the PM260 can be combined with the control units within the Sinamics G120 inverter series. The series features all the usual methods of open-loop and closed-loop control as well as vector control, voltage-frequency control and FCC (flux current control). In addition to the RSE232 and RS485 serial interfaces, communication is possible via Profibus with Profidrive 4.0. Parameterisation is carried out using the basic operator panel (BOP) or the 'Starter' parameterising software. The required parameters can be loaded quickly and easily via a Micro Memory Card (MMC) or the BOP (cloning).
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