Impact of Untransposed 66kV Sub-transmission Lines on Voltage Unbalance
نویسندگان
چکیده
The level of voltage unbalance that exists in some interconnected sub-transmission networks in Australia has been observed to be above the code requirements (e.g. 1% in Victoria). There is a perception that these high levels arise as a result of asymmetrical loads. However, the system asymmetry (of lines which are not normally transposed at 66kV, transformers and capacitor banks) also can play a significant part in the lead up to this situation. This lack evidence is partly due to the fact that analysis of asymmetrical systems require careful modelling of system components and lack of widespread availability and use of proper unbalanced load flow programs. To understand the impact of transmission lines in an interconnected network in relation to voltage unbalance, individual and interconnected behaviour of transmission lines have to be closely investigated under balanced supply and loading conditions. The paper presents the methodology and the results of such an investigation carried out employing an interconnected 66kV sub-transmission system as the study case.
منابع مشابه
Common-Mode-Current Generation Caused by Difference of Unbalance of Transmission Lines on a Printed Circuit Board with Narrow Ground Pattern
This paper explains a mechanism of commonmode generation on a printed circuit board with a narrow ground pattern. A transmission line has its value of degree of unbalance. At a connection point of two transmission lines having different degrees of unbalance, common mode voltage is generated proportional to the difference, and it drives common mode current. The authors propose a method to evalua...
متن کاملTransmission line parameter identification using PMU measurements
Accurate knowledge of transmission line (TL) impedance parameters helps to improve accuracy in relay settings and power flow modeling. To improve TL parameter estimates, various algorithms have been proposed in the past to identify TL parameters based on measurements from Phasor Measurement Units (PMU’s). These methods are based on the positive sequence TL models and can generate accurate posit...
متن کاملارزیابی کارآیی TCSCدرکاهش اضافه بار خطوط و پایداری ولتاژ درهنگام وقوع خطا
Although many mathematics-based and heuristic approaches have been recently developed on optimally allocation of TCSCs for lines overloads reduction and buses voltage stability enhancement during fault conditions, the works on the TCSCs efficiency to achieve the abovementioned goals are rare. This idea that TCSCs can surely enhance the system’s security must be comprehensively investigated. In ...
متن کاملA Novel Approach on Voltage Unbalance Improvement using SFCL on Electric Railway System
This paper presents a novel approach to determinethe power system stability using resistive superconducting faultcurrent limiter (SFCL) of an electric power grid (EPG). Inaddition, the electric railwaysystem has rapidly changing loadcharacteristics in time. An unbalance is generated owing to therapidly changing large single-phase loads. Subsequently, the unbalanced load causes an unbalanced tra...
متن کاملFault Locating in High Voltage Transmission Lines Based on Harmonic Components of One-end Voltage Using Random Forests
In this paper, an approach is proposed for accurate locating of single phase faults in transmission lines using voltage signals measured at one-end. In this method, harmonic components of the voltage signals are extracted through Discrete Fourier Transform (DFT) and are normalized by a transformation. The proposed fault locator, which is designed based on Random Forests (RF) algorithm, is train...
متن کامل