SYSTEM FOR DIAGNOSTICS AND PROTECTION AGAINST EARTH FAULTS OF CABLE AND OVERHEAD LINES 6-35 kV

Apply

SYSTEM FOR DIAGNOSTICS AND PROTECTION AGAINST EARTH FAULTS OF CABLE AND OVERHEAD LINES 6-35 kV

Journal Title: Machinery and Energetics - Year 2018, Vol 0, Issue 283

Abstract

The development of distributed generation, including wind power, requires an increase in the reliability of the operation of cable lines with a voltage of up to 35 kV, which are used to concentrate electrical energy from individual generators. In the construction of wind farms continues to operate rural air lines of the same voltage class. Timely detection of the occurrence of defects in the insulation of power lines will eliminate the causes of short circuits and emergency shutdowns. The aim of the work is the development of a microprocessor device for diagnosing the state of insulation and protection against single-phase earth faults of transmission lines. The principle of operation of the device is based on monitoring the values of the zero sequence currents with the help of cable zero-sequence current transformers. To provide high sensitivity to low values of currents that arise when insulation defects appear, it is proposed to use additional magnetomotive force in current transformers with a frequency that differs from the industrial one. Due to this, the operating point passes to the steeper section of the characteristic. The scheme of the device based on industrial microprocessor protection is proposed. The microprocessor system of determination of phase closures on the ground and defects of isolation in operating modes of cable and air (with a cable insert for a zero sequence transformer) of electric power lines, the principle of which is based on the control of zero currents, is proposed. In the proposed system, increasing sensitivity to known protections is ensured by the use in the cable transformer of a zero-sequence current of an additional magneto-driving force, the frequency of which differs from the industrial frequency. The device passed laboratory and industrial tests and is recommended for implementation.

Authors and Affiliations

М. В. ГРЕБЧЕНКО, О. В. КОЖУХАР

Keywords

EP ID EP388509
DOI -
Views 67
Downloads 0