Synchrophasor measuring device and inter-bus-line phase angle difference measurement unit using the same
AssigneeMitsubishi Electric Corporation
InventorKempei Seki
Life of this patent
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Abstract
Voltage instantaneous value time-series estimation data and a present-time voltage estimation value are calculated by using an actually-measured frequency and voltage instantaneous value time-series data according to a least square method. A present-time voltage effective value is determined by using the calculated voltage instantaneous value time-series estimation data, and a present-time synchrophasor, a voltage distortion degree and an inter-bus-line synchrophasor phase angle difference are determined by using the present-time voltage effective value and the present-time voltage estimation value.
Claims6
A synchrophasor measuring device, comprising:
- a voltage measuring unit for measuring a time-series data associated with a system voltage;
- a frequency calculating unit for determining the amplitude, chord length and rotational phase angle of a voltage rotational vector from the time-series data obtained by the voltage measuring unit according to an integration method and calculating a real-time frequency by identifying a frequency variation rate step by step;
- a voltage instantaneous value time-series estimation data and voltage effective value calculating unit for calculating a voltage instantaneous value time-series estimation data and a voltage effective value for estimating a sinusoidal coefficient parameter according to a least square method by using the real-time frequency and voltage instantaneous value time-series data of respective phase components;
- and a synchrophasor calculating unit for calculating a synchrophasor by using the voltage instantaneous value time-series estimation data and the voltage effective value.
Dependencies are inferred from the claim text.