RU39231U1 - SINUSOIDAL VOLTAGE FREQUENCY METER - Google Patents

Abstract

The utility model is designed to quickly measure the frequency of a sinusoidal voltage and can improve the speed of the frequency meter. The meter contains a clock pulse generator 1 with one output, an analog-to-digital converter 2, five microcircuits of buffer registers 3-7 and two microcircuits of permanent memory 8, 9. The converter 2 has an analog input A, a synchronization input C, and an eight-bit output Q1-Q8. Chips 3, 4, 5, and 6 have an eight-bit data input D1-D8, a synchronization input C, and an eight-bit output Q1-Q8. The register chip 7 has an eight-bit data input D1-D8, a write enable input E, a synchronization input C, and an eight-bit output Q1-Q8. Microcircuit 8 has 24 address inputs A1-A24, synchronization input C, and eight-bit output Q1-Q8. Microcircuit 9 has 16 address inputs A1-A16, a synchronization input C and a single-bit output Q. The output of the generator 1 is connected to the synchronization inputs of all elements of the meter. The input of the meter is the analog input A of the converter 2. The outputs Q1-Q8 of the converter 2 are connected to the data inputs D1-D8 of the microcircuit 3. Three registers 3, 4, 5 are connected in series. The outputs Q1-Q8 of registers 3, 4, 5 are connected to the address inputs A1-A24 of chip 8: the outputs Q1-Q8 of register 3 are connected to the address inputs A1-A8, the outputs Q1-Q8 of register 4 are connected to the address inputs A9-A16, and the outputs Q1-Q8 of register 5 are connected to address inputs A17-A24. The outputs Q1-Q8 of the chip 8 are connected to the data inputs D1-D8 of the chips 6 and 7, as well as the address inputs A1-A8 of the chip 9. The address inputs A9-A16 of the chip 9 are connected to the outputs Q1-Q8 of the chip 6. The output Q of the chip 9 is connected with the recording permission input E of the microcircuit 7. Microcircuit outputs

Description

A useful model for measuring equipment and is intended for quick measurement of the frequency of a sinusoidal voltage (measurement is performed in a time shorter than half a period) and can be used to create measuring devices for relay protection and automatic control of electric power systems.

An analog-digital measuring frequency relay of the RSG-11 type is known, described (see. Technical description and operating instructions IGFR.647526.001 T01), the principle of operation of which is based on the fact that the counter counts high-frequency pulses during the period (or half-period) of the signal under study. . Frequency measurement takes place over a period of time equal to the period of the signal under study.

However, this device has a low speed.

Known measuring relay of the frequency difference RGR-1104 (see. Technical description and instruction manual IAEZH.648 246.001TO OBK.469.581 Edition 1.), which is part of the automatic synchronization synchronous generator, the principle of which is based on a comparison of the frequencies of two signals: a signal (voltage of a synchronous generator) and a reference signal (voltage of an electric power system). This comparison is carried out by integrating two voltages (test and reference). Capacitors of measuring circuits are used as integrators.

However, such a device has a low speed due to the inertia of the integrators. The total time of measuring the frequency of the studied signal is not less than the period of this signal.

Closest to the proposed utility model is a microprocessor-based sinusoidal voltage frequency meter

automatic excitation regulator ARV-M (see Electrical Manual, Volume 3. - M .: MEI Publishing House, 2002. - pages 668-670.), containing an analog-to-digital converter, the analog input of which is the input of the meter, a clock generator, the output of which is connected to the synchronization inputs of all elements of the meter, and a computing unit, the input of which is connected to the output of the analog-to-digital converter, and the output is the output of the meter.

The disadvantage of this meter is the low speed, because frequency measurement takes place over a period of time equal to the period of the signal under study.

The technical task of the utility model is to increase the speed of the frequency meter.

This is achieved by the fact that in the known sinusoidal voltage frequency meter containing an analog-to-digital converter, the analog input of which is the input of the meter, a clock pulse generator, the output of which is connected to the synchronization inputs of the meter, and a computing unit, the input of which is connected to the output of the analog-to-digital converter, and the output is the output of the meter, the computing unit is made in the form of five microcircuits of buffer registers and two microcircuits of permanent memory, while the first three microcircuits The buffer registers are interconnected in series, the outputs of the analog-to-digital converter are connected to the inputs of the first buffer register microcircuit, and the outputs of all three buffer register microcircuits are connected to the address inputs of the first permanent memory microcircuit, the outputs of which are connected to the data inputs of the fourth and fifth buffer register microcircuits and with one half of the address inputs of the second permanent memory chip, the other half of the address inputs of which are connected to the outputs of the fourth chip of the buffer reg tra and the output of the second permanent memory chip is connected to the enable input

records of the fifth microcircuit of the buffer register, the outputs of which are the output of the computing unit.

The essence of the utility model is illustrated by the drawing, which shows the diagram of the frequency meter of the sinusoidal voltage.

The sinusoidal voltage frequency meter comprises a clock pulse generator 1, an analog-to-digital converter 2, five microcircuits of buffer registers 3-7 and two microcircuits of permanent memory 8, 9. The clock generator 1 has one output. The A / D converter 2 has an analog input A, a synchronization input C, and an eight-bit output Q1-Q8. Chips buffer registers 3, 4, 5 and 6 are the same. They have an eight-bit data input D1-D8, a synchronization input C, and an eight-bit output Q1-Q8. The buffer register chip 7 has an eight-bit data input D1-D8, a write enable input E, a synchronization input C, and an eight-bit output Q1-Q8. The permanent memory chip 8 has 24 address inputs A1-A24, synchronization input C, and eight-bit output Q1-Q8. The read-only memory chip 9 has 16 address inputs A1-A16, a synchronization input C, and a single-bit output Q.

The output of the clock pulse generator 1 is connected to the synchronization inputs of all elements of the meter: with the input C of the analog-to-digital converter 2, with the inputs C of the microcircuits of the buffer registers 3-7, with the inputs C of the microcircuits of the permanent memory 8 and 9. The input of the sine voltage frequency meter is the analog input And the analog-to-digital converter 2. The outputs Q1-Q8 of the analog-to-digital converter 2 are connected to the data inputs D1-D8 of the buffer register 3 chip. Three buffer registers 3, 4, 5 are connected in series: outputs Q1 -Q8 of buffer register 3 are connected to data inputs D1-D8 of buffer register 4, and outputs Q1-Q8 of buffer register 4 are connected to data inputs D1-D8 of buffer register 5. The outputs Q1-Q8 of buffer registers 3, 4, 5 are connected to address inputs A1-A24 memory chips 8: outputs Q1-Q8 buffer register 3

connected to address inputs A1-A8, outputs Q1-Q8 of buffer register 4 are connected to address inputs A9-A16, and outputs Q1-Q8 of buffer register 5 are connected to address inputs A17-A24. The outputs Q1-Q8 of the permanent memory chip 8 are connected to the data inputs D1-D8 of the buffer registers 6 and 7, as well as to the address inputs A1-A8 of the permanent memory chip 9. The address inputs A9-A16 of the permanent memory chip 9 are connected to the outputs Q1-Q8 buffer register microcircuits 6. The output Q of the permanent memory chip 9 is connected to the write enable input E of the buffer register microcircuit 7. The outputs Q1-Q8 of the buffer register 7 are the outputs of the sinusoidal voltage frequency meter.

The frequency meter of the sinusoidal voltage operates as follows.

The clock generator 1 generates pulses at equal time intervals Δt. The analog input A of the analog-to-digital Converter 2 receives the measured sinusoidal voltage. Analog-to-digital Converter 2 is in standby mode. The clock generator 1 supplies pulses to the synchronization input C of the analog-to-digital converter 2. The operation of the analog-to-digital converter 2 occurs along the leading edge of these pulses. As a result, numbers (binary codes) are formed at the outputs Q1-Q8 of the analog-to-digital converter 2 at discrete time instants - these are readings of the measured sinusoidal voltage. The numbers are written into the microcircuits of the buffer registers 3, 4, 5 by the leading edge of the pulses of the clock 1. This also writes the current number from the output of the analog-to-digital converter 2 to the microcircuit of the buffer register 3, then this number is written to the microcircuit of the buffer register 4 and further to the buffer register microcircuit 5. As a result, at the current moment of time, the following discrete values of the measured sinusoidal voltage will be recorded in the buffer register registers 3, 4, 5: in the buffer register microcircuit 3 and recorded current value U _3,

in the chip of the buffer register 4, the previous value of U _{2 is} recorded, and in the chip of the buffer register 5, the value of U ₁ preceding the value of U _{2 is} recorded. These values (U ₁ , U ₂ , U ₃ ) form the address of the memory cell of the permanent memory chip 8.

The permanent memory chip 8 has a memory capacity of 16 MB × 1 byte. The memory cells of this microcircuit are pre-recorded with numbers that are determined by one of the two expressions below:

where π = 3.1415,

T is the period of operation of the clock generator 1,

U ₁ is the number applied to the address inputs A1-A8 of the permanent memory chip 8,

U ₂ is the number applied to the address inputs A9-A16 of the permanent memory chip 8,

U ₃ is the number fed to the address inputs A17-A24 of the permanent memory chip 8.

In the above expressions, square brackets mean the whole part of the calculations (the fractional part is discarded). If the above expressions show zero in the denominators of fractions, then units are written to all bits of the memory cell at the corresponding address.

Each of the numbers U ₁ , U ₂ , U ₃ varies in the range from 0 to 255. Substituting all possible combinations of the numbers U ₁ , U ₂ , U ₃ into the expression (1) or (2) (the number of such combinations is 2 ²⁴ ≈ 16 · 10 ⁶ ), we get an array of numbers, which is written into the permanent memory chip 8. Thus, the permanent memory chip 8 is programmed to calculate the result using one of the expressions: (1) or (2).

When a high voltage level (i.e., logical 1) appears at the synchronization input C of the read-only memory chip 8, the result of the calculation of one of the indicated expressions will appear at its output.

Before giving this result to the output of the sinusoidal voltage frequency meter, this result is corrected. The data input D1-D8 of the buffer register 6 chip receives the number from the output of the permanent memory chip 8. The number is written to the buffer register 6 chip along the leading edge of the pulses of the clock 1, and the number changes at the output of the constant memory chip 8 after the leading edge clock generator 1 (when the value of this pulse becomes equal to logical 1). As a result, the previous output value of the read-only memory chip 8 appears in the buffer register 6 chip, two numbers arrive at the address inputs of the read-only memory chip 9: the current and the previous output value of the read-only memory chip 8.

The permanent memory chip 9 has a memory capacity of 64 kbytes1bit. Numbers are pre-recorded in the memory cells of this microcircuit, which are determined by the following condition: if the number supplied to the address inputs A1-A8 of this microcircuit differs in absolute value from the number applied to the address inputs A9-A16 by more than 2, then to the memory cell at the corresponding address, 0 is written. If the difference between the indicated numbers in absolute value does not exceed 2, then 1 is written to the memory cell.

Thus, the permanent memory chip 9 is programmed to compare two of these numbers. If the difference between these numbers in absolute value does not exceed the number 2, then at the output Q of the microcircuit of permanent memory 9 a logical 1 is formed, which is fed to the write enable input E of the buffer register 7. If the write enable input E of the buffer register 7 is high level (logical unit), then writing to this chip new data is allowed. Otherwise (at the input E of this microcircuit there is a low level voltage, i.e. logical zero), recording is prohibited. This means that no new data will be written to the buffer register chip 7, so the status of the outputs Q1-Q8 of this chip will not change. The number is written into the chip of the buffer register 7 by the trailing edge of the pulses of the clock generator 1 in the presence of a logical 1 at the input E of this chip. As a result, a new result will appear at the output of the sinusoidal voltage frequency meter (this is the output of the buffer register microcircuit 7). If the output Q of the chip of permanent memory 9 is logical O, then writing a new number to the chip of buffer register 7 is prohibited. This means that the number at the output of the buffer register chip 7 does not change. Accordingly, the output value of the sinusoidal voltage frequency meter will not change. In the next period of the clock generator 1, all processes are repeated.

Using the utility model provides an increase in the speed of measuring the frequency of a sinusoidal voltage.

Claims (1)

A sinusoidal voltage frequency meter containing an analog-to-digital converter, the analog input of which is the input of the meter, a clock pulse generator, the output of which is connected to the synchronization inputs of the meter, and a computing unit whose input is connected to the output of the analog-to-digital converter, and the output is the output of the meter, characterized in that the computing unit is made in the form of five microcircuits of buffer registers and two microcircuits of constant memory, while the first three microcircuits of buffer registers the cores are connected in series, the outputs of the analog-to-digital converter are connected to the inputs of the first buffer register microcircuit, and the outputs of all three buffer register microcircuits are connected to the address inputs of the first read-only memory chip, the outputs of which are connected to the data inputs of the fourth and fifth buffer register microcircuits and with one half of the address inputs of the second read-only memory chip, the other half of the address inputs of which are connected to the outputs of the fourth buffer register chip, and the WTO output second non-volatile memory chip is connected to the write enable input of the fifth register of the buffer circuit, the outputs of which are the output of the computing unit.