Any standard or custom system integrity protection schemes (out-of-step, equipment overload, under frequency, overvoltage) can be implemented using TPA-01 devices. TPA-01 can be mounted in a standard 800x600x2200 mm panel. These IEDs may implement several local SIPS functions simultaneously given that there is a required number of analog inputs, binary inputs and outputs. TPA-01 protection schemes may be based on user-defined algorithms. These devices provide flexible configuration at commissioning and maintenance stages. Fig. 1 illustrates an example when out-of-step protection and equipment overload protection schemes are implemented using two TPA-01 IEDs. Out-of-step protection is implemented to identify asynchronous mode using line parameters and to initiate control actions for electric power network decoupling.

Equipment overload protection is implemented to identify increased power flow over power line in a certain direction and to initiate specific control signals. Fig. 1 illustrates two electric power generation facilities and one substation. When there are no faults in the system, generators operate in synchronous mode. Due to specific reasons (for example, line fault), generators synchronous operation may be disturbed. TPA-01 must obtain data about three phase currents (Ia, Ib, Ic) and three phase voltages (Ua, Ub, Uc) of the supervised bay. To enable secondary circuits failures supervision function, TPA-01 must also obtain voltages from VT open delta winding. As it can be seen, it is required to process 9 analog values to implement out-of-step
protection. All other parameters required to implement the function (power, resistance, etc.) are calculated on the basis of phase currents and voltages. Equipment overload protection function requires the same three phase currents and three phase voltages. Given that it is reasonable that two mentioned functions reside in the single IED (as shown in Fig. 1). Ambient temperature measurements, required for the correct operation of equipment overload protection function are introduced in TPA-01 using UNC-1 IED. The latter receives measurements from the remote sensor and sends data over Ethernet network using GOOSE messages (IEC 61850‑1).

Trip signals are transferred to specific circuit-breakers. Along with trip signals, automatic reclosing inhibit signals are generated. After decoupling, network original schema restoration is only possible by operator. Fig. 1 shows two TPA-01 IEDs, operating in a hot standby mode. They perform the same asynchronous mode elimination function on the same bay, providing control signals for the specific circuit-breakers. 

Equipment overload protection function generates control signals for circuit-breakers of the feeders, providing power supply of the customers. In Fig. 5 such circuit-breaker is B4, which is remote for TPA-01 IED, implementing this function. In this case control signals are transferred to the remote facility over fiber-optic communication channel via AVANT K400.

Figure 1.
Implementing out-of-step equipment overload protections using TPA-01 IED

Implementing out-of-step equipment overload protections using TPA-01 IED