Guatemalan hydropower plants equipped with Hitachi Energy's RTUs to enable efficient remote control
For the automation of several small hydropower plants in Guatemala Hitachi Energy’s certified partner COMCARSA delivered a complete protection, control and supervision panel. The hydropower plants each have only a limited reservoir capacity so the control of the water level represents a critical input for the operation of the whole system. The hydropower plants generate an essential amount of energy for the region, therefore the reliable operation of the plants is necessary. As the small dams at each plant can hold only a small amount of water for the impulse of the turbines, the current water level has to be precisely monitored and controlled to ensure a reliable system operation.
For the modernization and automation of the hydropower plants Hitachi Energy and COMCARSA provided several RTUs which were installed in the substation and at the dams. In the substation the small and efficient 560CIG10 which offers high functionality in a compact design handles the communication with the IEDs, the automatic voltage regulator and the RTUs in the field via IEC 61850 and Modbus. Furthermore, the communication to the control center is handled via DNP3.0. In addition, the integrated I/Os of 560CIG10 collect the data from the turbine devices. The implemented PLC programming enables operation sequences customized to the restrictions of the hydropower plants. The RTU PLC implementation covers the start and stop of the generator, the load regulation based on the available water in the reservoir and the reactive regulation around the set point.
In the field the installed 560CIG10 measures the water level at each dam and reports the data to the RTU in the substation. Additionally, the RTU also handles RTU 560CIG10 in the substation the control of the valves and reports the status to the substation. The collected variables include temperature and pressure, injectors position, oil level, filter status, motor start confirmation and bypass position as well as emergency stop. Records of the collected information is also processed and stored for future reference.
The automation and standardization of the system brought along many advantages for the customer. Thanks to the remote access through standard protocols problems within the network can be quickly detected and restored. The compact system minimized the field control wiring and the start-up times. Furthermore, the availability of the HMI at the main plant is secured. Further extensions can be easily implemented into the new system. The modern and easy to- understand equipment also enables the companies operating the generation complex to work with only minimal training.