Voltage compensation for an A-C network supplying a rapidly-changing load

US4357570A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Eberhard Schmid · Dormitz, DE
• Wolfgang Kaufhold · Recklinghausen, DE

Key dates

• Filing date: Sep 22, 1980
• Grant date: Nov 2, 1982
• Expiry date: Sep 22, 2000

Classification

• Technology area (CPC G): Physics
• CPC primary: G05F1/44
• WIPO field: Control
• WIPO sector: Instruments

Abstract

A circuit for controlling the voltage of a network which supplies electrical power to a load having a rapidly varying impedance. The circuit contains a pair of controlled electric valves which are connected in parallel between two conductors of the network and poled for condition in opposite directions. A voltage transformer produces a signal corresponding to the network voltage, which signal is conducted to an integrator and subsequently compared to a preset mean value. The preset mean value corresponds to a desired amplitude at which the positive and negative half-wave cycles of the network voltage are desired to be maintained. In one embodiment, the controlled electric valves are caused to conduct current during respective half-waves of network voltage so as to maintain the amplitudes of the half-waves at the present mean value. Other features are described for compensating for long term drift of the network voltage and for controlling the controlled electric valves by means of logic circuitry.