Analysis and Improvement of the Methods and Systems for Measurement of the Frequencies of the Harmonic Signals

The article presents briefly the problems involved in measurement of the frequency of a signal. For solving the task of reduction of the time in the narrow frequency range of a signal input a priori information is used about the model of the measuring signal, a new method for measurement of the frequency of a harmonic signal. The method is based on the formation of the secondary voltage shifted in relation to the input at an arbitrary angle and on the use of the instantaneous and additional input signals for determination of the frequency. In contrast to the already known methods it enables us to define the frequency in the period of time considerably less than the period of the input signal. A block diagram of the measurement tools which implements the method is presented. An analysis was done of the errors due to deviation of the real heartbeat of the harmonic model. It was demonstrated that the error value was largely determined by not only the harmonic structure of a real signal, but also by the duration of exemplary time interval and the angle of the shit of the additional signal in relation to the input one. The article presents the results of the analysis of the error arising due to imperfect phase-shifting block not intended for formation of an additional signal. Opportunities for reduction of the errors by modifying the parameters of the measuring process were considered. The obtained results allow us to evaluate a possibility of using the method and means of its implementation, depending on the spectral composition of the input signal and requirements for the measurement accuracy. The analysis showed that the most appropriate areas for application of the method were: control of the parameters of the position and moving sensors with a low-frequency output, as well as determination of the rate of the frequency change.

частота, гармоническая модель, мгновенные значения сигналов, средство измерения, фазосдвигающий блок, погрешность, frequency, harmonic model, instantaneous values, means of measurement, signals of phase-shifting units, error

1. Ратхор Т. С. Цифровые измерения. АЦП/ЦАП. М.: Техносфера, 2006.

2. Зайцев С. Цифровые методы время-частотных измерений // Современная электроника. 2009. № 6. С. 20-23.

3. Petrovic P., Marjanovic S., Stevanovic M. New algorithm for measuring 50/60 Hz AC values based on the usage of slow A/D converters // IEEE Trans, on Instrum. and Meas. 2000. Vol. 49, Iss. 1. P. 166-171.

4. Belega D., Dallet D., Petri D. Accuracy of the Normalized Frequency Estimation of a Discrete-Time Sine-Wave by the Energy-Based Method // IEEE Trans, on Instrum. and Meas. 2012. Vol. 61, Iss. 1. P. 111-121.

5. Zhu L. M., Song X. M., Li H. X., Ding H. High accuracy estimation of multi-frequency signal parameters by improved phase linear regression // Signal Processing. 2007. Vol. 87, Iss. 5. P. 1066-1077.

6. Мелентьев В. С., Батищев В. И. Аппроксимационные методы и системы измерения и контроля параметров периодических сигналов. М: ФИЗМАТЛИТ, 2011.

7. А. с. 1185260 (СССР). Устройство определения частоты переменного напряжения / А.-С. С. Саухатас, Я. Я. Приедите (СССР). Опубл. 30.10.88, Бюл. № 40.

8. Мелентьев B. C., Синицын А. Е., Миронов А. А. Методы измерения частоты на основе сравнения гармонических сигналов, сдвинутых в пространстве и разделенных во времени // Информационно-измерительные и управляющие системы. Самара: Самар. гос. техн. ун-т, 2013. № 1 (8). С. 75-79.

9. Мелентьев B. C., Иванов Ю. М., Миронов А. А. Исследование метода измерения частоты гармонических сигналов // Ползуновский вестник. 2013. № 2. С. 198-201.

10. Мелентьев B. C., Ярославкина Е. Е., Синицын А. Е., Муратова В. В. Исследование методов измерения частоты выходных сигналов датчиков // Южно-Сибирский научный вестник. 2014. № 1 (5). С. 54-56.

11. Мелентьев B. C., Иванов Ю. М., Муратова В. В. Исследование метода измерения частоты гармонических сигналов по мгновенным значениям сигналов // Южно-Сибирский научный вестник. 2014. № 2 (6). С. 32-34.