ERMAKOV-FEDOROV FREQUENCY METRE FOR ELECTRIC POWER SYSTEMS AND ELECTRIC POWER STATIONS (VERSIONS) Russian patent published in 2009 - IPC G01R23/02 

FIELD: electrical engineering.

SUBSTANCE: group of inventions (versions) relates to information measuring and computer engineering and can be used in electrical power engineering for monitoring and recording frequency values after each period, average value and frequency standard for a day and averaged frequency values in industrial networks of alternating current with nominal frequency of 50 or 60 Hz, as well as for obtaining signals which control systems for controlling generators, automatic frequency load shedding (AFLS) and automatic frequency limitation devices (AFL). 1) The first version of the frequency metre comprises an input terminal (IT), low pass filter (LPF), analogue comparator (AC), reference voltage source (RVS), monostable multivibrator, counter, timer, rectangular pulse generator (RPG), register, multiplier unit (MU), adder, subtracting unit (SU), divider, read-only memory (ROM), first and second multiplier factor units (MFU), personal computer (PC), microcontroller (MC), transceiver, timer clock; 2) the second version of the frequency metre comprises an input terminal, low pass filter, analogue comparator, reference voltage source, monostable multivibrator, counter, timer, rectangular pulse generator, register, multiplier unit, adder, subtracting unit, divider, read-only memory, first and second multiplier factor units, personal computer, microcontroller, transceiver, timer clock; 3) the third version of the frequency metre comprises an input terminal, low pass filter, analogue comparator, reference voltage source, first and second random-access memory, timer, rectangular pulse generator, first and second registers, first and second adders, multiplier unit, subtracting unit, divider, indicator, first and second multiplier factor units, first - third counters, binary to binary-decimal code coder (BBDCC), flip-flop, AND element, first - third OR elements, first - tenth monostable multivibrators, digital-to-analogue converter (DAC), output terminal; 4) the fourth version of the frequency metre comprises a first and second input terminals, low pass filter, analogue comparator, reference voltage source, first and second random-access memory, timer, "ГНИ", first and second registers, first and second adders, multiplier unit, subtracting unit, divider, indicator, first and second multiplier factor units, first - third counters, binary to binary-decimal code coder, flip-flop, AND element, first - third OR elements, first - tenth monostable multivibrators, digital-to-analogue converter, buffer element (BE), output single-bit terminal, output multibit terminal; 5) the fifth version of the frequency metre comprises an input terminal, low pass filter, analogue comparator, reference voltage source, first - third timers, "ГНИ", timer clock, binary to binary-decimal code coder, indicator, first - fourth random-access memory, read-only memory, personal computer, microcontroller, transceiver, digital-to-analogue converter, first and second buffer elements, first and second multiplier units, first - third adders, first and second subtracting units, first and second dividers, first - third multiplier factor units, first and second units for assigning highest frequency codes, first and second units for assigning lowest frequency codes, first - fourth digital comparators, first - fourth registers, first - eighth counters, first - third flip-flops, first - fourth power amplifiers, first - seventh AND elements, first - seventh OR elements, first - seventeenth monostable multivibrators, first - fifth output terminals; 6) the sixth version of the frequency metre comprises an input terminal, low pass filter, analogue comparator, reference voltage source, first - third monostable multivibrators, rectangular pulse generator, timer, first and second registers, first and second multiplier factor units, multiplier unit, adder, subtracting unit, divider, first and second counters, indicator, D-flip-flop, AND and NOT elements, bistable switch.

EFFECT: increased functional capabilities due to possibility of monitoring frequency in industrial electrical networks, recording of the average value and frequency standard for a day, processes for changing frequency during emergencies and at time intervals prior to emergencies, as well as obtaining signals which control systems for controlling generators, automatic frequency load shedding and automatic frequency limitation devices, simplification of the design of the device, increase in its operating speed and accuracy.

6 cl, 6 dwg