Solusyon sa Komprehensibong Proteksyon sa Mataas na Voltaheng Kapasitor

Core Objective:​​ Para siguraduhon ang ligtas ug stable nga operasyon sa mga capacitor ug power grid, ug pagpadayon sa lifespan sa mga equipment.

Pagka-operasyon sa mga high-voltage capacitors sa power grid, importante kaayo ang robust nga sistema sa proteksyon. Kini nga solusyon, batasan sa industriya ug praktikal nga karanasan, naghatag og guidelines sa configuration para sa key nga mga hakbang sa proteksyon:

​I. Core Electrical Parameter Protection​

1. ​Overvoltage Protection:​​
• ​Function:​​ Para maprotektahan ang capacitor dielectric gikan sa cumulative damage o instantaneous breakdown gikan sa atmospheric overvoltages (lightning), switching overvoltages, ug system steady-state overvoltages.
• ​Configuration:​​
• ​Surge Arrester (MOA - Metal Oxide Arrester):​​ Gisulod sa line end ug neutral end sa capacitor bank, lalo na sa line side ug neutral point side, aron maepektibo nga clamp ang lightning surges ug peak sa switching overvoltages.
• ​Overvoltage Relay:​​ Nag-continuous monitoring sa terminal voltage sa capacitors. Kon ang voltage mogawas sa set value (typical 1.1Un), it trips ang capacitor bank human sa time delay aron malikayan ang prolonged overvoltage operation. Ang setting determination nanginahanglan og comprehensive consideration sa permissible fluctuation range sa sistema.
2. ​Overcurrent Protection:​​
• ​Function:​​ Para mobati sa abnormal nga pagtaas sa current gikan sa internal o external overloads sa capacitor bank, o internal component breakdown.
• ​Configuration:​​
• ​Time-Delayed Overcurrent Protection:​​ Nagsilbi isip backup protection sa main capacitor bank protection ug nag-handle sa system overloads. Ang setting nanginahanglan og coordination ug ride through inrush currents during energization, typical set at 1.5 to 2 times the rated current.
• ​Instantaneous Overcurrent Protection:​​ Nag-target sa severe short-circuit faults ug instantaneously tripping aron malikayan ang fault.
3. ​Short-Circuit Protection:​​
• ​Function:​​ Naghatag og extremely fast fault clearing kon may internal o external phase-to-phase faults o single-phase-to-ground faults involving the capacitors.
• ​Configuration:​​
• ​Dedicated High-Voltage Fuse:​​ Ang preferred protection para sa internal faults within an individual capacitor unit. Instantly fuse upon fault occurrence, isolating the faulty unit while allowing the rest of the bank to continue operating.
• ​Circuit Breaker + Relay Protection:​​ Naghatag og backup short-circuit protection functionality. Coordination between fuse operation and breaker tripping times must be ensured.

​II. Key State Monitoring and Protection​

1. ​Temperature Protection (Thermal Protection):​​
• ​Function:​​ Para maprotektahan gikan sa explosions o fires gikan sa abnormally high temperatures resulting from overcurrent, harmonics, poor ventilation, internal dielectric aging, o component breakdown (which may initially be indicated by fuse operation).
• ​Configuration:​​
• ​Embedded Temperature Sensors (PTC/Pt100):​​ Embedded at key heat dissipation points (e.g., top of capacitor casing) to monitor internal hotspot temperature in real-time.
• ​Temperature Relay / Intelligent Monitoring Unit:​​ Receives signals from the sensors. Activates when the temperature exceeds a safe threshold (e.g., 75°C - 80°C), issuing alarms or trip commands.
2. ​Harmonic Protection and Mitigation:​​
• ​Function:​​ Para supress "harmonic amplification" effects on the capacitors caused by system harmonics, which lead to severe overcurrent, overheating, and rapid equipment aging.
• ​Configuration:​​
• ​Harmonic Monitoring Meter:​​ Continuously monitors the Total Harmonic Distortion (THD) and individual harmonic content of current/voltage on the busbar or capacitor circuit. Issues alarms upon abnormality.
• ​Harmonic Filters:​​ In environments with severe harmonic pollution or for large capacitor banks, prioritize installing ​filter capacitor banks​ with matching reactance ratios (e.g., with 6%, 13% reactors) instead of pure compensation capacitor banks. In extreme cases, configure ​Active Power Filters (APF)​.

​III. Safety Assurance and Operational Control​

1. ​Grounding Protection:​​
• ​Function:​​ Para maprotektahan ang personnel ug equipment safety pinaagi sa provision og effective path para sa fault current.
• ​Configuration:​​
• Reliable grounding of the metal enclosure; grounding resistance must comply with regulations.
• One terminal of the secondary winding of the discharge coil/resistor must be grounded.
• Install open-delta voltage protection in systems with non-effectively grounded neutrals.
2. ​Disconnecting Switch (Isolator):​​
• ​Function:​​ Creates a visible break during maintenance, ensuring no risk of back-feed and providing a safe isolation point.
• ​Configuration:​​ Install disconnecting switches with visible air breaks on the source side (line side) of the circuit breaker. Operation must strictly follow the "Five-Prevention" interlocking mechanism.
3. ​Automatic Trip Device (Interlock Protection):​​
• ​Function:​​ Comprehensively determines faults or abnormal operating conditions at the control system level to achieve intelligent tripping.
• ​Configuration:​​
• Multiple criteria (voltage, current, temperature, fuse operation signals, etc.) are integrated into the protection and control unit.
• Automatically initiates trip logic during abnormal conditions, driving the circuit breaker to operate. Integrated within the Substation Automation System (SAS).