Beckhoff has announced the release of the EL3783 oversampling EtherCAT Terminal for power monitoring for standard control systems. Conventional automation and power measurement technology are increasingly converging, and with the integration of the EL3783 I/O terminal, grid analysis becomes available for a range of power-generating systems. Three-phase AC voltage systems up to 690 V can be analyzed simultaneously on six channels and with 20 ksamples/s directly in the PLC.
For each of the three phases, the EL3783 EtherCAT Terminal from Beckhoff samples voltages up to 400/690 Vrms and currents up to one or five Arms as instantaneous values with 16-bit resolution. The six terminal channels are evaluated simultaneously based on the EtherCAT oversampling principle, with a temporal resolution of 50 µs, which is significantly faster than the cycle time of the controller. Using the EtherCAT distributed clocks functionality, it is also possible to measure synchronously (<< 1 µs) with other EtherCAT devices in systems of virtually any size and detect propagating grid faults.
Data with relevant details are available in the control system if true RMS and performance calculations or complex user-specific algorithms are used to analyze the voltage and current curves. In addition, the EL3783 EtherCAT Terminal achieves 650 percent of the nominal one-ampere measuring range through automatic current range switching, with a maximum measurement error of 0.2 percent (of the full scale value).
In conjunction with TF3650 software, the TwinCAT 3 Power Monitoring library from Beckhoff, the EL3783 Terminal represents a measurement system for detailed network analysis that is integrated into standard PC-based control technology. In this way, requirements for network supporting measures in the event of voltage drops (LVRT, Low Voltage Ride Through) can be identified, or harmonics analysis can be used to implement condition monitoring.