Synchronizing device

• US 5,642,006 A
• Filed: 09/13/1995
• Issued: 06/24/1997
• Est. Priority Date: 03/19/1993
• Status: Expired due to Fees

• Current Assignee: ELIN Energieversorgung GmbH
• Original Assignee: ELIN Energieversorgung GmbH
• Inventors: Cech, Michael
• Primary Examiner(s): Martin, David S.
• Assistant Examiner(s): PALADINI, ALBERT WILLIAM
• Application Number:
  US08/513,863
• Time in Patent Office: 650 Days
• Field of Search: 307/87, 307/86, 307/85, 307/19, 322/44, 290/40, 341/116, 318/721
• US Class Current: 307/87
• CPC Class Codes: H02J 3/42 with automatic parallel connection when synchronisation is achieved

Abstract

A synchronizing device for a parallel connection of a synchronous generator and an a.c. network. The device includes a measuring circuit for measuring the voltage and frequency of the generator and the a.c. network and for measuring the phase angle between the generator and the a.c. network. The measuring circuit includes control outputs for regulating the rotational speed of the generator drive. A set value for the generator frequency includes a defined slip at the start of balancing. The measuring circuit also regulates the voltage output of the generator to match the a.c. network voltage. Once the phase angle between a.c. network voltage and generator voltage has fallen below a predefined value, null balance occurs.

Claims

1. A synchronizing device for a parallel connection of a synchronous generator and an a.c. network, said device comprising:

a measuring circuit for measuring a voltage and frequency of said generator and of said a.c. network, and for measuring a phase angle between said a.c. network and said generator voltages;

said measuring circuit comprising control outputs for an rpm regulator of a generator drive to adjust an actual value of said generator frequency to within a set value range;

said measuring circuit further for measuring a voltage regulation of said generator to adjust said generator voltage to said a.c. network voltage;

said measuring circuit further comprising a switching command output for a coupling switch and a computer, said switching command output triggerable by a predetermined set value calculated by said computer from a frequency difference and a predeterminable switching time of said coupling switch, p1 wherein, when said generator is initially started, said computer determines a plurality of optimal set commands for said rpm regulator by detecting a regulation response to each one of a plurality of respective set commands and stores said optimal set commands in a memory, each of said plurality of optimal set commands associated with a difference between said set value and said actual value of the frequency of said generator,

wherein, at a start of adjustment, a preset actual value for said generator frequency contains a defined slippage, and

wherein, when said phase angle between said a.c. network and generator voltage falls below a predefined value, synchronization is achieved.

2. The synchronizing device in accordance with claim 1, said control outputs for said rpm regulator adjusting said actual value of said generator frequency to match said network frequency.

3. The synchronizing device in accordance with claim 1, said switching command output triggerable during a set value adjustment of said voltage and frequency as a function of a set value adjustment of said phase angle.

4. The synchronizing device in accordance with claim 1, said computer determining an optimal command length and a command pause for said rpm regulator.