Method for controlling a direct current chopper controller

• US 8,111,055 B2
• Filed: 11/10/2008
• Issued: 02/07/2012
• Est. Priority Date: 11/28/2007
• Status: Active Grant

• Current Assignee: Kostal Industrie Elektrik GmbH
• Original Assignee: Kostal Industrie Elektrik GmbH
• Inventors: Landwehr, Frank
• Primary Examiner(s): Berhane, Adolf
• Assistant Examiner(s): Gblende, Jeffrey
• Application Number:
  US12/267,816
• Publication Number:
  US 20090134855A1
• Time in Patent Office: 1,184 Days
• Field of Search: 323/225, 323/268, 323271-272, 323282-286
• US Class Current: 323/272
• CPC Class Codes: H02M 1/0032 Control circuits allowing low power mode operation, e.g. in standby mode
• CPC Class Codes: H02M 3/1584 with a plurality of power processing stages connected in parallel
• CPC Class Codes: H02M 3/1588 comprising at least one synchronous rectifier element H02M3/1582, H02M3/1584 take precedence
• CPC Class Codes: Y02B 70/10 Technologies improving the efficiency by using switched-mode power supplies [SMPS], i.e. efficient power electronics conversion e.g. power factor correction or reduction of losses in power supplies or efficient standby modes

Abstract

A method of controlling a direct current (“DC”) chopper controller having a switch and a storage choke in which the choke has a current dependent on the switching of the switch on and off includes the following. A current variable derived from one of the time averaged value of the current of the choke and the peak value of the current of the choke is determined. A switching frequency for synchronizing the turning on and off the switch is calculated as a function of the current variable and on whether the current variable exceeds a current threshold. The switching frequency is determined to be a predetermined low frequency if the switching frequency is lower than the low frequency and is determined to be a predetermined high frequency if the switching frequency is greater than the high frequency. The switch is switched on and off in accordance with the switching frequency.

Claims

1. A method of controlling a direct current chopper controller having a transistor switch and a storage choke, wherein the storage choke has a coil current which depends on the switching of the switch on and off, the method comprising:

calculating a coil current variable derived from one of the time averaged value of the coil current of the storage choke and the peak value of the coil current of the storage choke;

calculating a switching frequency for synchronizing the turning on and the turning off of the switch as a function of the coil current variable and on the condition of whether the coil current variable exceeds a predetermined current threshold;

if the calculated switching frequency is lower than a predetermined low switching frequency, then setting the calculated switching frequency to be equal to the predetermined low switching frequency;

if the coil current variable is less than the predetermined current threshold, then setting the calculated switching frequency to be equal to the predetermined low switching frequency;

if the calculated switching frequency is greater than a predetermined high switching frequency, then setting the calculated switching frequency to be equal to the predetermined high switching frequency; and

switching the switch on and off in accordance with the calculated switching frequency.

2. The method of claim 1 wherein:

the coil current variable is the time averaged value of the coil current of the storage choke.

3. The method of claim 1 wherein:

the coil current variable is the peak value of the coil current of the storage choke.

4. The method of claim 1 further comprising:

setting the calculated switching frequency to be equal to the predetermined high switching frequency when the coil current variable exceeds the predetermined current threshhold.

5. The method of claim 1 wherein:

the predetermined current threshhold is dependent on at least one electrical variable.

6. The method of claim 5 wherein:

the at least one electrical variable include an input voltage to the storage choke and an output voltage of the storage choke.

7. A method of controlling a direct current chopper controller having first and second channels connected in parallel to one another, wherein each channel includes a transistor switch and a storage choke, wherein the storage choke of each channel has a coil current which depends on the switching of the switches on and off, the method comprising:

for each channel, calculating a coil current variable derived from one of the time averaged value of the coil current of the storage choke of the channel and the peak value of the coil current of the storage choke of the channel;

if the switch of the second channel is switched off, then switching the switch of the second channel on if the coil current of the storage choke of the second channel is greater than a predetermined off current threshold;

if the switch of the second channel is switched on, then switching the switch of the second channel off if the coil current of the storage choke of the second channel is less than a predetermined on current threshold;

calculating a switching frequency for synchronizing the turning on and the turning off of the switch of the first channel as a function of the coil current variable of the first channel and on the condition of whether the coil current variable of the first channel exceeds a predetermined current threshold;

if the calculated switching frequency is lower than a predetermined low switching frequency, then setting the calculated switching frequency to be equal to the predetermined low switching frequency;

if the coil current variable is less than the predetermined current threshold, then setting the calculated switching frequency to be equal to the predetermined low switching frequency;

if the calculated switching frequency is greater than a predetermined high switching frequency, then setting the calculated switching frequency to be equal to the predetermined high switching frequency; and

turning the switch of the first channel on and off in accordance with the calculated switching frequency.

8. The method of claim 7 wherein:

the coil current variable for each channel is the time averaged value of the coil current of the storage choke of the channel.

9. The method of claim 7 wherein:

the coil current variable for each channel is the peak value of the coil current of the storage choke of the channel.

10. The method of claim 7 further comprising:

setting the calculated switching frequency to be equal to the predetermined high switching frequency when the coil current variable for the first channel exceeds the predetermined current threshhold.