US 6,291,911 B1 · Electrical switchgear with synchronous control system and actuator

Abstract

In a power distribution system, synchronizing switchgear operations with an AC voltage or current waveform can be accomplished more precisely with a closed-loop feedback, microprocessor-based motion control design. By employing a closed-loop feedback, microprocessor-based design, switchgear contact position and velocity can be monitored and optimized in real time during a switching operation, thereby assuring a more accurate switching operation. Moreover, the closed-loop feedback design intrinsically compensates for the effects of such things as ambient temperature, AC waveform fluctuations, and changes in the physical condition of the switchgear. The closed-loop position feedback design is also capable of optimizing various transfer function parameters associated with the closed-loop feedback process, both during and subsequent to a switching operation, to further assure that switching operations are more accurately synchronized with the AC voltage or current waveforms.

Claims48

Dependent claims

A closed-loop feedback control system for electrical switchgear comprising:

a microprocessor;
a current generation means, operatively coupled to said microprocessor, for providing a driving current required to regulate an actuator for moving at least one of two switchgear contacts in the electrical switchgear;
and
a position feedback means, operatively coupled to the at least one of two contacts, for repeatedly sampling position information of the at least one of two contacts and providing contact position information to the microprocessor,
wherein said microprocessor comprises means for controlling said current generation means in real-time, during a switching operation, as a function of an initial contact position and a present contact position, as provided by said position feedback means, such that the at least one contact transitions from the initial contact position to a final contact position in accordance with a pre-defined motion profile so as to provide AC waveform synchronized switching.

2 more elements

A capacitor switch comprising:

a current interrupter containing at least one moveable contact;
an actuator coupled to the at least one moveable contact;
a closed-loop feedback, motion control circuit comprising:
a microprocessor,
a pulse-width modulation (PWM) circuit, operatively coupled to said microprocessor, wherein said PWM circuit produces driving current for said actuator which is required to drive the at least one moveable contact from an initial contact position to a final contact position during a switching operation,
a position sensor optically coupled to the at least one contact to repeatedly sample position data of the at least one moveable contact,
a decoder, wherein said decoder receives and decodes the contact position data from said position sensor and forwards the decoded contact position data to said microprocessor,
wherein said microprocessor includes closed-loop feedback means for controlling contact position and velocity in real-time, during the switching operation, based on the initial contact position, a present contact position feedback signal and a present contact velocity feedback signal, such that the switching operation is synchronized with an AC voltage waveform across the capacitor switch.

5 more elements

A closed-loop feedback method for controlling at least one contact in an electrical switchgear during a switching operation, said method comprising the steps of:

generating a driving current required to move the at least one contact;
generating contact position feedback in real-time, during the switching operation, by repeatedly receiving samples of a position of the at least one contact;
and
controlling the generation of driving current required to regulate the movement of the at least one contact in real-time, during the switching operation, as a function of an initial contact position and the real-time contact position feedback data, such that the at least one contact transitions from the initial contact position to a final contact position in accordance with a pre-defined motion profile so as to provide AC voltage or current waveform synchronized switching.

1 more element

Dependencies are inferred from the claim text.

Electrical switchgear with synchronous control system and actuator

Life of this patent

Electrical switchgear with synchronous control system and actuator

Life of this patent

Abstract

Claims48