How It Started

The Kerala State Electricity Board (KSEB) is in the process of creating a 500kW solar power plant in a 110kV substation in Ponnani. The turnkey project was handed over to KELTRON.

Requirements

The KSEB required a solution for the supply and installation of a String Monitoring Unit(SMU), SCADA and a weather monitoring station with a sensor to monitor and control a 500kW grid tie solar power plant.

Operation

Using SCADA, an operator can view both historical and real time data along with an option to monitor and control the data remotely over the Internet. SCADA uses Modbus RTU protocol to communicate with weather monitoring stations, SMUs and inverters.

A typical weather monitoring station includes pyranometers,wind speed sensors, ambient temperature sensors and module temperature sensors. Environmental sensors provide analogue values in the range of 4-20 mA. A converter integrates all the the analog signals to RS485 and communicates with the PLC and SCADA.

A breaker is hardwired to the PLC. This regulates the status from the breaker and the breaker is controlled without any delays,

The pyranometers  are stored according to the guidelines and data can be generated as reports in the form of trends and cumulative graphs. This system is integrated into the network and serves three web-based clients.