Sistema ng automatikong pangangalaga ng linya ng distribusyon ng mataas na presisyon na PMU

Ang sistema ng automasyon ng pagprotekta ng linya ng pamamahagi ng PMU ay isang bagong sistema ng automatikong pamamahagi ng linya.

para sa kasalukuyang problema lalo na ang earth fault.

na batay sa Synchronous Phasor Measurement-μPMU ng Distribution Network.

PMU (phasor measurement unit), isang independiyenteng aparato o modyulo. Ang mga data ng sampling ng voltage/current ay may timestamp ng BDS/GPS na tumpak hanggang sa US level.

Pangunahing mga function:• Phasor: amplitude, phase Angle,• Frequency (f) at Frequency Variation (△f/△t)

Diagrama ng Block ng Arkitektura ng Hardware ng μPMU

Wide Area Measurement System (WAMS)
• Ang mga sukat ng PMU ay absolutong nagsasabay sa World
Standard Time (UTC)
• Wide-area measurement synchronization ng maraming PMUs
na nakainstala sa iba't ibang lugar
• Mathematical expression ng voltage/current signal:

Overhead Current Sensor i-WCS – Single Channel Current PMU

Sagot sa problema ng distribution network na batay sa distribution network PMU at wide area synchronous phasor measurement technology.

• Mataas na presisyon at mataas na frequency na current acquisition
• Wide-area synchronized, power induction
• Live installation, IP67 protection
• Suporta ng bi-directional power flow o ring network operation
• 3G/4G/ 5G communication：
a. Periodically report each harmonic
b. Local events trigger the upload data
c. Remote call and test specific moment data

• 1μs Wide-area synchronized
• 12.8kHz Sample frequency
• 60 min Wave record and playback
• 0.5 Measuring accuracy
• 3.5A Full function minimum operating current

Cable Type Current Sensor RCMU – Multichannel Current PMU

RCMU - Underground cable current sensor

• 1μs Wide-area synchronized
• 12.8kHz Sample frequency
• 0.5 Measuring accuracy
• 60 min Data Playback
• 3 current measuring
• Wireless/wired remote transmission

• Collect three-phase current, same as overhead type principle, suitable for ring main unit, switching station, substation.
• Wide area synchronous, induction power, or 24V/48V DC power supply
• Local fault decision algorithm based on current:
a. Short-circuit overcurrent
b. Zero sequence overcurrent
c. Asymmetric phase current
• Wave record called measurement, Support distributed fault location
• Support bi-directional power flow or ring network operation
• 3G/4G/5G or network communication

Bus Collecting Unit BDCU – Single/Multiple Voltage PMU

Indoor type at Outdoor type

• 220V AC/24V DC power supply• Fiber optic, wired, wireless
• IEC 60870-5- 101/104/DNP3• 300 current sensors can be accessedVoltage Acquisition：
• 1μs Wide-area synchronized
• 1.0 Measuring accuracy
• 12.8kHz Sampling frequency
• 60 min Wave record playback

Para sa single-phase grounding fault na may ground current na mas malaki kaysa 1A, ang detection at positioning accuracy ay 100%, na walang maling positive
• Collect zero sequence voltage, start recording of earth fault
• Collect and process the recording wave, and determine the fault comprehensively
• Safe access to the main power distribution station
a. Used as the station grounding insulation monitoring device
b. Used as an in-station grounding insulation monitoring device
c. Do not rely on the master station to complete the fault

The Composition of Intelligent Distribution Network Condition Monitoring System Based on PMU Measurement

Distribution Network Usage Scenarios

Typical Use of PMU - Line Condition Assessment

Typical Use of PMU - Distributed Wave Recording

Ang recording data ng lahat ng monitoring points sa linya at estasyon ay may label ng absolute time sa antas ng microsecond. Anumang device maaaring trigger ang recording kapag ang preset na start conditions ay nasakop. Ito ay nagbibigay ng "snapshot" ng buong network batay sa callback ng oras ng anumang event sa anumang lugar hanggang sa recorded data ng lahat ng sensors. Ito ay nagbibigay ng global data para sa detalyadong pag-analisa ng mga event at nagpapadali ng proseso ng inversion, traceability, at early warning ng abnormal state, atbp.

Typical Use of PMU - Power Quality Monitoring

09/07/2023