Method and apparatus for optimizing the output power of a rectifier

• US 6,577,516 B1
• Filed: 03/05/2001
• Issued: 06/10/2003
• Est. Priority Date: 07/01/1998
• Status: Expired due to Term

• Current Assignee: Vertiv Energy Systems, Inc. (Emerson Electric Company)
• Original Assignee: Emerson Energy Systems AB
• Inventors: Thoren, Christer, Sahlstrom, Thomas
• Primary Examiner(s): BERHANE, ADOLF D
• Application Number:
  US09/720,750
• Time in Patent Office: 827 Days
• Field of Search: 363/84, 363/125, 363/78
• US Class Current: 363/84
• CPC Class Codes: H02M 1/0045 Converters combining the concepts of switch-mode regulation and linear regulation, e.g. linear pre-regulator to switching converter, linear and switching converter in parallel, same converter or same transistor operating either in linear or switching mode
• CPC Class Codes: H02M 1/007 Plural converter units in cascade push-pull DC/DC converters with pre-regulator H02M3/3374; DC-AC converters following a DC-DC stage including a high frequency transformer H02M7/4807; DC-AC converters following a DC-DC conversion stage generating periodically varying voltages H02M7/4826
• CPC Class Codes: H02M 3/28 using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate ac
• CPC Class Codes: H02M 7/217 using semiconductor devices only

Abstract

A rectifier comprising a preregulator (11; 21) and a DC/DC converter (13; 23) is disclosed, comprising means for controlling the output power P_OUT from the DC/DC converter in dependence of the input power to the preregulator. A method of controlling such a rectifier by controlling the output power P_OUT in dependence of the input current I_IN is also disclosed. This ensures that the output power from the rectifier is never higher than what the preregulator can supply. As a result the rectifier according to the invention may be used at any power level and any input conditions. The output power P_OUT may be controlled by controlling the output current I_OUT from the DC/DC converter.

Claims

1. A rectifier having a preregulator having an AC input and a DC output and a DC/DC converter, the rectifier comprising means for using a status signal to control the output power from the DC/DC converter in dependence of the input power that can be handled by the preregulator at any given time;

said rectifier comprising a processing unit for processing the status signal before feeding it as a control signal to the DC/DC converter;

said processing unit comprising;

a filter unit for filtering the status signal;

a subtraction unit for obtaining a difference signal between the filtered signal and an output current reference signal;

an error amplifier for comparing the difference signal to the output current from the DC/DC converter, the result of the comparison constituting the control signal to the DC/DC converter.