Totally self-checking checkers with separate internal fault indication

1988 ◽  
Vol 37 (10) ◽  
pp. 1206-1213 ◽  
Author(s):  
N. Gaitanis
Keyword(s):  
Internal Fault

A new principle of UHVDC line pilot protection based on trigger angle control characteristics

2020 ◽  
Vol 21 (4) ◽  
Author(s):  
Lu Wang ◽  
Zhenxing Li ◽  
Tan Hong ◽  
Hanli Weng ◽  
Zhenhua Li
Keyword(s):  
Control System ◽  
Trigger Delay ◽  
Internal Fault ◽  
Internal Parameters ◽  
Simulation Based ◽  
Transition Resistance ◽  
Change Tendency ◽  
Pilot Protection

AbstractA new principle of UHVDC Line pilot protection based on internal parameters of the trigger angle of converter is proposed, in order to improve the ability of the protection to withstand transition resistance. Through the analysis of UHVDC control system, it is found that, due to the regulation of control system, in terms of trigger delay angle of rectifier side and trigger leading angle of inverter side, the change tendency in internal fault and external fault is different. Thus, the protection criterion is constructed. Compared with the traditional protection principle using voltage and current to establish protection criteria, this principle uses internal parameters as protection quantity. The simulation based on PSCAD/EMTDC verifies the effectiveness of the protection principle.

scholarly journals Numerical Differential Protection of Power Transformer using Innovative Algorithm

2019 ◽  
Vol 8 (5S3) ◽  
pp. 438-446
Keyword(s):  
Power Transformer ◽  
Algorithm Design ◽  
Point Of View ◽  
Inrush Current ◽  
Current Transformers ◽  
Simulink Model ◽  
Internal Fault ◽  
Safety And Reliability ◽  
Operating Current ◽  
Primary Current

This paper presents a new innovative algorithm for Numerical Differential Relay design of transformer. Fault information is critical for operating and maintaining power networks. This algorithm provides accurate performance for transformer by which is independent of system conditions such as: External fault, Inrush current, CT saturation. Locating transformer faults quickly and accurately is very important for economy, safety and reliability point of view. Both fault-detection and protection indices are derived by using Numerical Differential Relay algorithm design of transformer. The embedded based differential and operating current measurement device is called numerical differential relay is among the most important development in the field of instantaneous fault operation. Numerical relay provides measurement of differential current and operating current at power transformer above 5MVA in substation. Simulation studies are carried out using MATLAB Software show that the proposed scheme provides a high accuracy and fast relay response in internal fault conditions. Current transformers form an important part of protective systems. Ideal Current Transformers (CTs) are expected to reflect the primary current faithfully on the secondary side. Under conditions the CT saturates, and hence it cannot reproduce the primary current faithfully. This paper deals with simulation methods for determining CT performance under different factor. A Simulink model has been developed to observe CT response under steady state w.r.t Burden, Turns ratio, Asymmetrical current, Hysteresis conditions. Thus, it is now possible to evaluate the CT performance under these factors

Simulation Design of Transformer Differential Protection Based on Mat Lab

2013 ◽  
Vol 722 ◽  
pp. 282-286
Author(s):  
Hong Hua He
Keyword(s):  
Simulation Model ◽  
Relay Protection ◽  
Fault Current ◽  
Differential Protection ◽  
Protection Device ◽  
Simulation Design ◽  
Transformer Protection ◽  
Internal Fault ◽  
Simulation Results ◽  
Transformer Differential Protection

The microprocessor-relay protection device has gradually replaced regular simulation relay protection it is also difficult to visually determine protection device malfunction or tripping. Therefore, the use of the Mat lab toolbox to build transformer differential protection simulation model, the simulation results show that two-line ratio brake can correctly identify internal fault current, and rapidly remove fault, and the system also can provide convenient for microprocessor transformer protection.

Sign in / Sign up

Export Citation Format

Share Document