Current differential based WIDE AREA protection (WAP) has recently been proposed as a technique to increase the reliability of protection systems. It increases system stability and can prevent large contingencies such as cascading outages and BLACKOUTs. This paper describes how power differential protection (PDP) can be used within a WAP and shows that the algorithm operates correctly for all types of system faults whilst preventing unwanted tripping, even if the data has been distorted by CT saturation or by data mismatches caused by delays in theWAP data collection system. The PDP algorithm has been simulated and tested on an Iranian 400kV transmission line during different fault and system operating conditions. The proposed operating logic and the PDP algorithm were also evaluated using simulation studies based on the Northern Ireland Electricity (NIE) 275 kV network. The results presented illustrate the validity of the proposed protection.

LPWANs are a class of technologies that have very low power consumption and high range of communication. Along with its various advantages, these technologies also have many limitations, such as low bandwidth, connectionless transmission and low processing power, which has challenged encryption methods in this technologies. One of the most important of these challenges is encryption. The very small size of the message and the possibility of packet loss without the gateway or device awareness, make any of the cipher chaining methods such as CBC, OFB or CTC impossible in LPWANs, because either they assume a connection oriented media or consume part of the payload for sending counter or HMAC. In this paper, we propose a new way to re-synchronize the key between sender and receiver in the event of a packet being lost that will enable us to perform cipher chaining encryption in LPWAN limitation. The paper provides two encryption synchronization methods for LPWANs. The first method can be synchronized in a similar behavior as the proof of work in the block chain. The second proposed method is able to synchronize the sender and receiver with the least possible used space of the message payload. The proposed method is able to synchronize the parties without using the payload. The proposed method is implemented in the Sigfox platform and then simulated in a sample application. The simulation results show that the proposed method is acceptable in environments where the probability of missing several consecutive packets is low.

Background and aim: According to the frequent tooth loss at molar sites and necessity to replace them, the purpose of this study was to evaluate the short term clinical and radiographic outcomes of fresh molar sockets immediately implanted, with tapered WIDE platform implants.Materials and Methods: 10 patients with the mean age of 46 were treated with the immediate implantation of 12 WIDE diameter and WIDE platform implants in the molar sites.Following the atraumatic extraction of molars and preservation of the interradicular septum, implantswere placed. Immediately after the insertion of healing abutment, implant primary stability was tested with the Periotest and the crestal bone level was estimated with the periapical long-cone radiographs.Four months later patients were recalled for final evaluations, the crestal bone loss was measured and the periotest values were judged with the Wilcoxon test.Results: All 12 implants were reported with no pain, infection and continuous radiographic lucency.The average PTV1 and PTV2 reported were -4.9±0.99 and -4.6±1.37 (-2 to -7).The difference between PTVs wasn' t statistically significant (P>0.05).The average crestal bone loss was 0.54±0.96.Conclusion: Successful results were achieved with WIDE diameter and WIDE platform implants with the appropriate case selection and surgical technique.

Occurrence of large power deficits are the main cause of black outs in power systems. Usually, large power deficits occure as a result of large generating units or tie-lines outage. Considering the impact of electricity on economic growth of countries and daily life of people, triggering a BLACKOUT might be a goal of sabotage or military attacks.Underfrequency load shedding is commonly used to prevent BLACKOUT in case of large power defcits. In fact by curtailing part of the loads, load shedding schemes retain the power balance and keep the system stability. In this paper, an underfrequency load shedding method based on WIDE AREA monitoring system is proposed. In this load shedding scheme, the amount of load to be shed, in case of large power deficits, to preserve the stability of power system is determined based on the estimated minimum frequency. The effectiveness of the proposed method in different conditions, considering power system parameters variation, is proved using simulation studies.

This paper presents an online scheme of a WIDE-AREA-damping-controller (WADC) for controlling the inter-AREA oscillatory modes in interconnected power systems using WIDE-AREA power system stabilizers and measuring signals. The proposed adaptive controller includes two individual approaches WSSS for evaluating the signal participation factor selection and GPSS as a global power system stabilizer for damping inter-AREA oscillations. For this purpose, considering the concept of center of inertia over inter-AREA signals, generators with the highest interactions are determined as oscillating AREAs while based on evaluating signal damping ratio, proper participation factors are estimated in which GPSS with positive damping performance is developed. In real-time working mode, based on oscillatory signals gathered from WAMS data, different combinations of PSSs are evaluated in which the combinations with the best controllability on damping the oscillations are selected. The effectiveness of the proposed WIDE-AREA damping controller scheme is evaluated on the IEEE test system and practical Iran national power grid with the potential of unstable inter-AREA oscillations. Results show the effectiveness of the proposed WADC approach for fast and secure damping of inter-AREA oscillation.

Increasing power transfer capability of existing transmission lines is one of the key issues in the power systems. Inter-AREA oscillations have effect on the power transfer capability and decrease the network efficiency. On the other hand, FACTS devices can be used to increase the power transfer capability by damping the inter-AREA oscillations. This paper proposes a Linear Matrix Inequality (LMI) based robust controller design to generate an additional stabilizing signal for a Static VAR Compensator (SVC) in order to increase damping of the inter-AREA modes. WIDE AREA Measurement (WAM) has been employed by the controller which is designed based on the H∞ mixed-sensitivity synthesis method. The effectiveness of the method is investigated by a test system consisting of 16 numbers of generators, 68 buses and 5 AREAs. The results show good and robust performance of the controller in damping the oscillations.