IMPROVING POWER FACTOR IN AC POWER SYSTEM

摘要

Disclosed is a system for improving power factor in an AC power system. The power system has an AC power source and an electrical load that are interconnected by at least one power conveying line. The system also comprises a power factor-improving circuit including at least one channel that comprises a channel-level bidirectional electron tube circuit and at least one associated reactive impedance element connected between a power conveying line of the AC power system and ground. Each channel-level bidirectional electron tube circuit is responsive to a control system for connecting or disconnecting at least one associated reactive impedance element when needed for improving power factor. Each channel-level bidirectional electron tube circuit also comprises one bidirectional cold-cathode field-emission electron tube rated at medium to high voltage or two unidirectional cold-cathode field-emission electron tubes rated at medium to high voltage and connected in an anti-parallel manner.