| 摘要 |
FIELD: electricity. ^ SUBSTANCE: invention realises direct measurement of active and reactive components of bushing insulation leakage current, voltage and frequency of grid with calculation of tgdelta and capacity of bushing insulation, adjustment of annunciation and protection by preset limit values of tgdelta and capacity. Device consists of devices for connection to object, which are connected to measuring outlets of bushings, units of current circuits protection, which are connected to outlets of connection devices, units of galvanic isolation and normalisation of current signals with current transformers at the inlets, which are connected to outlets of units of current circuits protection, units of galvanic isolation and normalisation of voltage signals by measuring voltage transformers at the inlet, which receive inlet signals from network voltage transformer, multiplexers of analog current and voltage signals, measurement unit. Measurement unit includes inlet multiplexer of analog signals, multiplier digital to analog transducer (DAT), low frequency filter (LFF) and outlet analog to digital transducer. Units of reference system signals generation represents closed system of phase self-tuning of frequency, which includes multiplier DAT and pulse generator that is connected sequentially with it in LFF and controlled by voltage, binary counter and transducer of codes, the output data bus bar of which is connected to digital inlet of multiplier digital to analog transducer. Device also includes: communication unit, which contains imaging elements, keyboard and communication interface, unit of connection with system of annunciation and protection, communication interface with system top level, generator of calibrating signal, which is made in the form of digital to analog transducer, managing controller. ^ EFFECT: improves validity and reliability of pre-accident condition determination and expansion of functional resources. ^ 3 cl, 3 dwg |
