MODIFICATIONS OF DIODE RECTIFIER CIRCUITS FOR CONTINUOUS INSULATION MEASUREMENT IN LIVE AC IT NETWORKS

• Дата: 2016
• Автор: Olszowiec, P.
• Формат: Стаття
• Мова: English; Russian
• Опубліковано: National Technical University "Kharkiv Polytechnic Institute" and State Institution “Institute of Technical Problems of Magnetism of the National Academy of Sciences of Ukraine” 2016
• Теми: low voltage AC IT networks; insulation resistance; diode rectifier; insulation resistance decline alarming; earth fault location; 621.317; сети низкого напряжения с изолированной нейтралью; сопротивление изоляции; диодный выпрямитель; сигнализация о понижении сопротивления изоляции; поиск места замыкания на землю; мережі низької напруги з ізольованою нейтраллю; опір ізоляції; діодний випрямляч; сигналізація про зниження опору ізоляції; пошук місця замикання на землю
• Онлайн доступ: http://eie.khpi.edu.ua/article/view/2074-272X.2016.2.08
• Назва журналу: Electrical Engineering & Electromechanics

Purpose. In the paper there are described few systems of insulation resistance continuous measurement using an imposed DC test signal delivered by diode rectifiers. Drawbacks of this technique are pointed out and ways of these shortcomings removal are proposed. Methodology.  An improved version of measuring circuit based on a single-phase diode rectifier is presented. Application of logometric measuring devices is suggested. Results. A new insulation resistance continuous measuring system is insensitive to network voltages variation and asymmetry. Modified circuit enables also implementation of a simple device for alarming the monitored network’s insulation deterioration and/or earth-fault protection. Originality. Formulas describing performance of diode rectifiers under asymmetrical supply have not been available so  far. Both innovations (i.e. single-phase diode rectifier and logometric meter) have not been applied widely for implementation of continuous insulation monitoring in live AC IT networks. Practical value.  Use of both innovations will allow to eliminate unrequired dependence of measurement results on variable network voltages as well as their possible asymmetry. Exploitation of diode rectifier circuits for earth fault location is also possible.