Paglutas sa mga Isyu sa Kahigpitan sa Pagkarga: Ang Ginabag-o nga Gidaghanon sa Digital na Metro para sa Grid sa Elektrisidad sa Oilfield

2yrs + staff 1000+m² US$300,000,000+ China

I. Paghiliusa ug Background

Mga instrumento sa pagsukol sa kuryente mahimong mga importante nga mga panilbihan alang sa ligtas, stable, ug ekonomikal nga operasyon sa grid sa kuryente. Tradisyonal, ang mga analog pointer-type electrical measurement indicating instruments gibag-ohan sa oilfield grid substations. Apan, uban sa pag-develop sa grid ug daghan nang mando sa matumong ug reliability sa pagsukol, ang mga pointer instruments nagpakita og daghang kaubanan sa long-term application, sama sa significant nga reading errors, inaccurate indication sa low loads, ug difficulties sa range matching.

Arin ang modernisasyon sa substation operation monitoring ug sigurado sa accuracy, intuitiveness, ug reliability sa data measurement, gi-rekomendahan niining proposal ang comprehensive upgrade gikan sa existing pointer instruments ngadto sa digital electronic instruments. Ang mga digital instruments, sama sa ilang high accuracy, ease of reading, strong anti-interference capability, ug convenient installation ug maintenance features, represent the ideal solution sa kasamtangan nga mga problema.

II. Kasamtangan nga Sitwasyon ug Analisis sa Problema (Limitations sa Pointer Instruments)

Ang kasamtangan ginagamit nga pointer instruments primarili naglutaw sa sumala nga urgent nga mga isyu:

Mga Reading Errors: Ang pag-depende sa manual visual reading madaling maghatag og parallax errors. Ang dili maayo nga mga metodo sa pagbasa usab makapahibalo sa human error, na kompromiso sa accuracy sa data.
Severe Inaccuracy sa Low Loads: Ang aktwal nga load sa oilfield substations kasagaran naka-range sa 5%-10% sa scale sa instrument. Apan, ang accurate indication range sa pointer instruments wala ra sa 20%-80% sa scale. Sa ingani nga low loads, ang mga reading mahimong mag-aglip sa actual value sa tens o even hundreds amperes, na render sa monitoring walay kalihukan.
Impractical Range Replacement: Arin ang pagdala sa indication sa accurate range, ang pagbag-o sa instrument range kinahanglan, apan kini kinahanglan match sa current transformer ratio. Tungod kay ang mga measurement ug protection transformers kasagaran gibag-ohan isip usa ka integrated unit, ang pagbag-o sa transformers naglakip og massive engineering work ug mataas nga cost, na make it impractical.

III. Solusyon: Advantages ug Application sa Digital Electronic Instruments

1. Measurement Principle

Ang mga digital instruments gigamit og advanced A/D (Analog-to-Digital) conversion technology. Unsa man ang continuous analog electrical quantities (like voltage, current) sila mosulbar sa discrete digital quantities sa dihang sukulan, proseso, ug ipakita. Kini fundamental nga adunay difference gikan sa direct analog driving mechanism sa pointer instruments.

2. Core Advantages Comparison

Ang mga digital instruments adunay overwhelming advantages gikan sa pointer instruments, as detailed in the table below:

Kategorya sa Advantage	Espesipiko nga Characteristics sa Digital Instruments
Display & Reading	Direct digital display provides intuitive, clear results; completely eliminates viewing angle errors; enables fast and convenient reading.
Measurement Performance	High accuracy with small measurement errors; high sensitivity, maintaining precise indication especially under low-load conditions.
Ease of Use	High input impedance minimizes impact on the measured circuit; no installation angle restrictions allow flexible layout; simple operation with fast measurement response.
Energy Consumption & Durability	Low self-power consumption, energy-efficient and environmentally friendly; good overload protection capability, less prone to damage from overloads.

3. Application Positioning

Batasan sa above nga advantages, ang mga digital electrical measuring instruments ang preferred solution alang sa instrument upgrades ug intelligent operation and maintenance sa oilfield grid substations. Sila effectively address the inherent drawbacks sa pointer instruments, significantly enhancing operational monitoring levels ug decision-making efficiency.

IV. Key Points for Implementation and Deployment

Arin ang smooth implementation ug long-term stable operation sa digital instrument retrofit project, ang sumala nga aspects require emphasis:

Auxiliary Power Supply Configuration:

Reliability Priority: Gi-rekomendahan nga ang auxiliary power supply sa instrument adunay source sa DC power system, o gikan sa reliable sources sama sa standby lighting circuits o circuits with backup power within the substation auxiliary power system. Kini prevents instrument power loss during a total substation power outage, which could lead to operator misjudgment.
Independent Protection: Each instrument's auxiliary power circuit should be equipped with a dedicated fuse or high-breaking-capacity miniature circuit breaker to ensure effective isolation in case of a fault.

Standardization and Aesthetics:

The type, panel color, cutout dimensions, etc., of the selected digital instruments should be standardized to maintain the overall aesthetics and consistency of the control panels/cabinets.

Anti-Interference Measures:

Given the complex electromagnetic environment within substations, select proven products that have passed tests for strong electric and magnetic field environments.
During the design and installation phases, pre-emptive measures like shielding and proper grounding must be implemented to ensure long-term stable operation of the instruments in harsh electromagnetic conditions.

Calibration and Maintenance Cycle:

All digital instruments should be included in a periodic calibration schedule, with a recommended calibration cycle of 1 year.
To ensure measurement accuracy, instruments should be powered on and preheated for 15 minutes before any important measurement or calibration.

Technical Support and Follow-up:

After the retrofit and commissioning, the supplier should conduct user follow-up visits, promptly address operational issues, and provide necessary technical explanations and training to operational personnel.

V. Calibration Methods for Key Digital Instruments

To guarantee measurement accuracy, all newly installed and periodically inspected digital instruments must be calibrated according to specifications. Below is an outline of the calibration process for main instrument types:

General Preliminary Steps: Connect the auxiliary power supply; check that the digital display or screen shows normally.
Ammeter Calibration: Connect wires according to the wiring diagram; apply a standard AC current (e.g., 5A); adjust the calibration potentiometer to meet specifications; then apply proportional currents (e.g., 2.5A, 1.25A) to verify linearity.
Voltmeter Calibration: First zero the instrument; then connect wires according to the wiring diagram corresponding to the voltage level (e.g., 35KV, 6KV); input a standard voltage (e.g., 100V); adjust the corresponding potentiometer for correct display; and verify linearity.
Active/Reactive Power Meter Calibration:

Use a standard source to output standard voltage and current, controlling their phase angle.
Active Power Meter: Zero the instrument at phase angle φ=90° (cosφ=0); adjust the full scale at φ=0° (cosφ=1); check linearity at points like φ=30°, 60°, etc.
Reactive Power Meter: Zero the instrument at phase angle φ=0° (sinφ=0); adjust the full scale at φ=90° (sinφ=1); and check linearity.

Power Factor Meter Calibration: Calibrate at a phase angle difference of 0° (Power Factor=1.00) and specific angles (e.g., 140°) to ensure accurate display values.