10.9.4 Voltage control (VCTR) TR1ATCC, TR8ATCC, TCMYLTC,TCLYLTCPrepare the IED for verification of settings outlined in section "Preparing the IED toverify settings".The automatic voltage control for tap changer, single control TR1ATCC is based ona transformer configuration that consists of one tap changer on a single two-windingpower transformer.The automatic voltage control for tap changer, parallel control TR8ATCC, if installed,may be set to operate in Master Follower (MF) mode, or Minimise Circulating Current(MCC) mode. The commissioning tests for each parallel control mode are addressedseparately in the following procedure.Secondary injection of load current (IL) and secondary bus voltage (UB) equivalentquantities are required during installation and commissioning tests. The test consistsmainly of:1. Increasing or decreasing the injected voltage or current at the analogue inputs ofthe IED.2. Checking that the corresponding commands (Lower or Raise) are issued by thevoltage control function.Setting confirmation is an important step for voltage control in the installation andcommissioning phase to ensure consistency of power systems base quantities, alarm/blocking conditions and parallel control settings for each transformer controlfunction.Before starting any test, verify the following settings in PCM600 or the local HMI forTR1ATCC, TR8ATCC and TCMYLTC and TCLYLTC.• Confirm power system base quantities I1Base, I2Base, UBase.Main menu/Settings/Setting Group N/Control/TransformerVoltageControl(ATCC,90)/TR1ATCC:x/TR8ATCC:x/GeneralandMain menu/Settings/Setting Group N/Control/TransformerVoltageControl(ATCC,90)/TR1ATCC:x.• Confirm that the setting for short circuit impedance Xr2 for TR1ATCC orTR8ATCC is in accordance with transformer data:• Short circuit impedance, available on the local HMI under Main menu/Settings/General settings/Control/Section 10 1MRK 511 360-UEN ATesting functionality by secondary injection156 Bay control REC670 2.1 IECCommissioning manual
