Sample calculation-for-differential-relays 1. Differential Relays 2. Principles are emphasized. 1. Transformer Protection Application Guide This guide focuses primarily on application of protective relays for the protection of power transformers, with an emphasis on the most prevalent protection schemes and transformers. Transformer Differential Relay • Ratio correction - Calculate interposing CT ratio at normal tap of transformer - Percent mismatch of CT must be lower than 5 % ... Overfluxing Relay for 500/230kV Tie Transformer RELAY SETTING CRITERIA 10 40 50 70 Overfluxing in PU. Our digital library saves in compound countries, allowing you to acquire the most less latency times … Time (sec.) This setting should be larger then the transformer magnetizing cur-rent and steady state CT errors during no load conditions. 3 : Model setting calculations-Transformer 1-132 4 : Model setting calculations- Shunt Reactor 1-120 5 : Model setting calculations- Busbar 1-15 6 : Relay setting guide lines for transmission lines 1-19 7 : Recommendations for protection system management 1-5 8 : Check list … Setting procedures are only discussed in a general nature in the material to follow. 2.1 Differential Relay Settings Calculations MiCOM P63X Relay Type: MICOM P63X Required Data Ratings of the Power and Current Transformers MVA Voltage Ratio Rated Voltage in kV (HV Side) Rated Voltage in kV (LV Side) Vector Group CT Ratio (HV Side) CT HV Side Vector Group CT Ratio (LV Side) CT LV Side Vector Group … relay settings and the selec tion of current transformers are described with examples. The Break 1 setting is based on the previously defined pu value of the full load trans-former … For part 2, 3, and 4 of Example 15.2, calculate the CT voltage if the phase relay burden is 1.2 , the residual relay burden is 1.8 , the lead resistance is 0.4 , and the CT resis-tance is 0.3 . Problem 1: – Determine the time of operation of a 5-ampere, 3-second over current relay having a current setting of 125% and a time setting, multiplier of 0.6 connected to supply circuit through a 400/5 current transformer when the circuit carries a fault current of 4000A. For this example, a Minimum Pickup setting of 0.1 pu is equal to 0.1×1000 A = 100 A differential current. Fig. ... EXCEL DECK WEIGHT AND COST CALCULATOR.XLS TRANSFORMER IDMT RELAY SETTING (10.6.13).XLSX BATTERYSIZECALCULATOR28-5-11.XLS SHORT CIRCUIT CALCULATION (10.6.13).XLS BATTERY BANK SIZE & INVETOR (10.6.13).XLS Neglect CT saturation in this calculation. This technical article will cover the gathering of information needed to calculate protective relay settings, the setting calculations for the various protective functions, typical generator/turbine withstand times for abnormal operating conditions, and the math associated with various types of impedance elements. Protective relay functions and data. For relay 50 connected at H.V side of the transformer: For such connection the pickup shall be more than the inrush current of the transformer. transformer protection relay setting calculation guide pdf is affable in our digital library an online entrance to it is set as public thus you can download it instantly. Otherwise the relay will trip during transformer … 3.2.2.-3 Configuration of vector group and earthing of power transformer The calculation of the vector group compensation is shown in Table 3.2.2.-1 below. Calculate Relay Pick up setting of IDMT Over current Relay from Downstream to Source End.