• South Eastern Equipment Company

Electronic Voltage Stabilisers, Solid-State

South Eastern Equipment Company (SEECO) offers solid-state instantaneous Electronic Voltage Stabilisers. The response time of a solid-state line regulator for dynamic changes in line and load is extremely rapid, relying not on mechanical motion but only on its inherent time constants for recovery. Recovery time for extreme changes in load is approximately 5 cycles, and for extreme changes in line approximately 10 cycles, on request a typical oscillograph is provided for line and load changes. Solid-state regulators provide a regulated output, voltage through the controlled firing of an inverse parallel paid of SCRs connected in shunt leg of an auto transformer. The corrective voltage produced at the auto transformer adds or subtracts vectorially from the input voltage, depending on the phase angle at which the SCRs are fired. The control section consists of an RMS voltage detector and control circuit. The RMS voltage detector monitors the output voltage and produces an error signal, which is used by the control circuit to direct gate drive to the appropriate SCR at the proper firing angle. Filters are connected across the auto transformer to minimise the harmonic content in the regulator output. The over current protection circuit senses the magnitude of the current flowing the SCRs leg and removes gate drive from the SCRs when the current exceeds a predetermined magnitude. Applications are in computers, CNC machines, data processing, photocopy machines, medical equipment, telecommunications, test instruments, X-ray units, radar/navigation aids, defence lab equipment, oil and gas pipelines, etc. Capacities available from 1 kVA to 300 kVA both single and three phase. Also available three phase to single phase static regulators for UPS application depending on customer requirements.