Activation of a synchronous rectifier

Patent metadata

Field	Value
Publication number	US-2016111972-A1
Application number	US-201514922806-A
Country	US
Kind code	A1
Filing date	Oct 26, 2015
Priority date	Sep 25, 2008
Publication date	Apr 21, 2016
Grant date	—

Abstract

A rectifier bridge circuit is described for rectifying the phase voltage generated by a generator, including a positive half-bridge having multiple rectifier elements and a negative half-bridge having multiple rectifier elements. The rectifier elements each have a controllable switch having a diode connected in parallel. A control circuit is provided for switching the switches on and off. The switch-on time t switch on setpoint and/or the switch-off time t switch off setpoint of the switch is/are computed based on a characteristic map or a mathematical function.

First claim

What is claimed is:

1 . A rectifier bridge circuit for rectifying the phase voltage generated by a generator, including a positive half-bridge having multiple rectifier elements and a negative half-bridge having multiple rectifier elements, the rectifier elements each having a controllable switch having a diode connected in parallel, and a control circuit being provided for switching the switches on and off, wherein the switch-on time t switch on setpoint and/or the switch-off time t switch off setpoint of the switch is/are computed based on a characteristic map or a mathematical function.

2 . The rectifier bridge circuit as recited in claim 1 , wherein the characteristic map or the mathematical function has as input parameters the generator rotational speed ng, or the generator rotational speed ng and the excitation current IE, or the generator rotational speed ng and the excitation current IE and the generator voltage UG, or the generator rotational speed ng and the excitation current IE and the rotational angle phi of the rotor.

3 . The rectifier bridge circuit as recited in claim 1 , wherein the characteristic map or the mathematical function has as input parameters the generator rotational speed ng and the ratio of the switched-on duration to the theoretical maximum switched-on duration (commutation time).

4 . The rectifier bridge circuit as recited in claim 2 or 3 , wherein the characteristic map or the mathematical function has as additional input parameters the change in the generator rotational speed ng, or the change in the generator rotational speed ng and the change in the excitation current IE, or the change in the generator rotational speed ng and the change in the excitation current IE and the change in the generator voltage UG, or the change in the generator rotational speed ng and the change in the excitation current IE and the change in the rotational angle phi of the rotor.

5 . The rectifier bridge circuit as recited in claim 1 , 2 , 3 , or 4 , wherein the value t switch on which is computed from the characteristic map or the mathematical function is used within the scope of a control.

6 . The rectifier bridge circuit as recited in claim 1 , 2 , 3 , or 4 , wherein a controller is present which adjusts t switch off based on t switch off setpoint and t switch off actual .

7 . The rectifier bridge circuit as recited in one of the preceding claims, wherein the controller controls more rapidly at a low rotational speed and/or small excitation currents.

8 . The rectifier bridge circuit as recited in one of the preceding claims, wherein the controller-based switch-on time is set to zero when the switch-on time of the switch exceeds the commutation time.

9 . The rectifier bridge circuit as recited in one of the preceding claims, wherein the derivative action within the characteristic maps or the mathematical function is greater for smaller excitation currents and/or lower rotational speeds.

10 . The rectifier bridge circuit as recited in one of the preceding claims, wherein the switch-on time of a switch is ascertained using a comparator.

11 . The rectifier bridge circuit as recited in claim 10 , wherein the diode forward voltage is used as the input variable for the comparator, and the switch is controlled at 0.7 V forward voltage, preferably 0.35 V diode forward voltage.

12 . The rectifier bridge circuit as recited in one of preceding claims 1 through 5 , wherein a regulation minimizes the switched-off duration t switch off to a value t switch off min .

13 . The rectifier bridge circuit as recited in claim 12 , wherein the controller-based switch-on time is set to a value t switch on setpoint based on the characteristic map or the mathematical function when the switch-on time of the switch exceeds the commutation time, the derivative action defining the percentage ratio of t switch off setpoint to the total commutation time.

Assignees

• Bosch Gmbh Robert

Inventors

• Wolf Gert
• Mehringer Paul
• Reutlinger Kurt
• Walter Gerhard

Classifications

• H02M2007/2195

  Electricity · mapped topic

• H02M7/219 Primary

  in a bridge configuration · CPC title

• H02M7/2195

  the switches being synchronously commutated at the same frequency of the AC input voltage · CPC title

• H02M7/162

  in a bridge configuration · CPC title

• Y02B70/10

  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 · CPC title