Control and monitoring of transformers with tap-changer and reactors
Freely programmable limit values
Measurement functions (U, I, P, cos ϕ, f etc.)
Momentary monitoring of measured values
Programmable analog inputs and outputs
Large backlit LCD (128 x 128) with all important information (tap, voltage etc.)
Freely programmable control structure according to special requirements and functions
Statistics function (total number of switching operations, switching operations per tap)
Programmable binary inputs and outputs
The actual value and a fixed or load-dependent setpoint value are continually compared in the regulator, which then determines the correct commands for the transformer’s tap changer. The regulator’s parameters can be fine-tuned to the dynamic time behaviour of the grid voltage to obtain high control performance for a low number of switching operations.
The values of all relevant variables of a three-wire, threephase system with balanced or unbalanced load are calculated from the measured CT & VT inputs. All of the measured and calculated values can then be viewed on the LCD display, or transferred by analogue signal and SCADA connection.
Up to two selectable analogue values can be continuously recorded and displayed as a line chart with an adjustable time grid. The tap position, setpoint value, tolerance band and Manual/Auto state, as well as the time and date are recorded in addition to these measured quantities. The stored values can also be retrieved and displayed by the WinREG Control software, using the REGView module.
The Statistics mode records all of the tap changer’s switching operations. Separate logs are stored for switching operations under load and without load. This information can be used to analyse how many taps were made in a certain timeframe, as well as how often a particular tap was selected. This information is then used to fine-tune the regulator’s settings. The stored values can also be retrieved and displayed by the WinREG Control software, using the Service module.
ParaGramer is an efficient tool that automatically detects which transformers have been switched into a parallel control scheme and displays this information via a single-line diagram. The artificial word ParaGramer is a combination of the terms parallel and single-line diagram. ParaGramer can monitor the positions of circuit breakers, isolators, bus ties and bus couplings. Based on the status of these inputs and of the regulators in the parallel scheme, the system automatically determines optimum tap positions for all of the transformers.
The Transformer Monitoring module collects and calculates information about the condition of the transformer and tap changer. The hot-spot temperature is calculated in accordance with IEC 60354 and IEC 60076, and is used to determine the transformers loss of life. The optional TM+ function evaluates the moisture content of the cellulose and the risk of bubble formation. Up to 6 groups of fans and 2 oil pumps can be controlled to regulate the temperature of the transformer. The operating times of the fans and pumps are stored for maintenance purposes. Oil temperature is measured either directly as a PT100 input, or via a mA transducer and also be recorded using the recorder mode.