High-accuracy grid frequency detection ASR-245H

Description

• The measuring device is mainly used for data acquisition and calculation,and realizes unified measurement of fundamental wave, harmonic and inter-harmonicsignals of power grid signals in the wide frequency domain.
• The wideband measurement processing unit is applied to receive, store and forward wideband measurement data, and features data analysis and preprocessing functions.
• It enables customized transmission of original measured data, preprocessed analysis data and diagnostic analysis result data to the master station.

Micro phasor measurement unit

Grid Synchronization Monitor-Synchronized Phasor Measurement

• Synchronously collect three-phase voltage and three-phase current at measurement points.Calculate three-phase fundamental voltage and three-phase fundamental current.
• Obtain positive-sequence fundamental voltage phasor, positive-sequence fundamental current phasor,system frequency and rate of change of frequency.

High-Precision Frequency Meter-Binary Quantity Acquisition

• Collect binary status information at measurement points,including circuit breaker positions and disconnector positions.

Grid-Connected Monitoring Device-Real-time Data Recording

• Continuously record the fundamental-frequency forward-sequence phasors of the measured voltage and current, the fundamental-frequency phasors of the three-phase voltage and current, the frequency, the rate of change of frequency, and the switch status signals;
• The device can generate event marks when the following power system events occur,to facilitate users to obtain dynamic data during event periods:

1.  Frequency out-of-limit;
2. Rate of change of frequency out-of-limit;
3. Amplitude over upper limit, including over-limit of positive sequence voltage,positive sequence current, negative sequence voltage, negative sequence current,zero sequence voltage, zero sequence current, phase voltage and phase current.
4. Amplitude below lower limit, including under-limit of positive sequence voltage, phase voltage, etc.
5. Binary state change
6. Low frequency oscillation
7.  Subsynchronous oscillation
8. Wideband oscillation
9. Harmonic current out-of-limit, harmonic voltage out-of-limit
10. Inter-harmonic voltage out-of-limit, inter-harmonic current out-of-limit
11. Grid connection trigger

• Record device alarm information, operation logs and binary state change records in real time.All data are stored in chronological order without loss after power failure,facilitating query and fault analysis for operators.

Subsynchronous and Supersynchronous Oscillation Monitoring

• Adopt sampled voltage and current values to calculate instantaneous power in real time and conduct spectrum analysis.Monitor oscillations within the instantaneous power range of 2.5~45Hz and 55~95Hz.
• Upload the top 10 dominant oscillation frequencies and corresponding amplitudes in descending order of oscillation intensity.

Wideband Oscillation Monitoring

• Calculate instantaneous power in real time with voltage and current sampling values and perform spectrum analysis.Monitor oscillations in the instantaneous power range of 100~300Hz.

Harmonic Monitoring