On‑load tap changer transformer-XinYa china manufacturer

Technical Functionality of the On‑Load Tap Changer

The on‑load tap changer (OLTC) is a sophisticated electromechanical device integrated into power transformers to regulate output voltage without interrupting the electrical supply. In dynamic power grids where load demand fluctuates constantly, maintaining a stable secondary voltage is critical for equipment safety and power quality. Unlike de-energized tap changers, which require the transformer to be disconnected for adjustment, the on‑load tap changer operates while the unit is energized and carrying current.

The core mechanism of an OLTC involves a diverter switch and a selector switch working in unison. During a tap change operation, the diverter switch momentarily transfers the load current to a transition resistor or reactor. This limits the circulating current between taps and prevents arcing, allowing the selector switch to move to the new tap position seamlessly. Once the connection is established, the current is transferred back, ensuring a continuous power supply.

Modern on‑load tap changer systems are often equipped with motor drive mechanisms and automatic voltage regulators (AVR). These controls monitor the grid voltage in real-time and execute tap changes to compensate for voltage drops or swells. This capability is essential for interconnecting transmission networks with varying potentials and ensuring that industrial facilities receive power within strict tolerance limits (e.g., ±5%), thereby enhancing the overall stability and reliability of the electrical infrastructure.

China XINYA Power Cables Co., Ltd Email: [email protected] Email: [email protected] whatsapp: +86 15289885778 Website: https://www.supplytransformer.com