Power Converter

• US 20150115872A1
• Filed: 03/26/2013
• Published: 04/30/2015
• Est. Priority Date: 03/30/2012
• Status: Abandoned Application

• Current Assignee: EH Europe GmbH (EnerSys)
• Original Assignee: EH Europe GmbH (EnerSys)
• Inventors: Letombe, David, Kechmire, Mohamed, Beaucamp, M. Francios
• Application Number:
  US14/388,611
• Publication Number:
  US 20150115872A1
• Time in Patent Office: Days
• US Class Current: 320/107
• CPC Class Codes: G01R 19/00 Arrangements for measuring currents or voltages or for indicating presence or sign thereof G01R5/00 takes precedence; for measuring bioelectric currents or voltages A61B5/24
• CPC Class Codes: G01R 21/006 Measuring power factor
• CPC Class Codes: G01R 21/06 by measuring current and voltage G01R21/08 - G01R21/133 take precedence
• CPC Class Codes: G01R 31/3648 comprising digital calculation means, e.g. for performing an algorithm
• CPC Class Codes: G01R 31/3842 combining voltage and current measurements
• CPC Class Codes: H02J 5/00 Circuit arrangements for transfer of electric power between ac networks and dc networks H02J3/36 takes precedence
• CPC Class Codes: H02M 1/0009 Devices or circuits for detecting current in a converter
• CPC Class Codes: H02M 3/3388 of the parallel type
• 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

The invention relates to a method and apparatus for calculating the input current being drawn by a power converter. The power converter may be connected to and charging a battery and the method includes the steps of measuring the current and voltage being supplied to the battery, along with the frequency at which the power converter is operating. The voltage being supplied to the power converter may be calculated using a pre-determined relationship with the current and voltage being supplied to the power converter and the frequency of operation. The voltage being supplied to the converter may then be used to calculate the current being drawn by the converter.

Claims

1. A method of calculating the input current being drawn by a power converter (I_mains), the power converter being connected to and charging a battery, the method comprising the steps of:

measuring the voltage being supplied to the battery (V_bat);

measuring the current being supplied to the battery (I_bat);

measuring the frequency at which the power converter is operating (f_converter);

calculating the voltage supplied to the power converter (V_mains) using a pre-determined relationship between V_bat, I_bat and f_convertor, and V_mains; and

using the value of V_mains to calculate the I_mains.

2. A method as claimed in claim 1, including the step of calculating the power output of the power convertor (P_out).

3. A method as claimed in claim 1, including the step of calculating the power input into the power converter (P_in).

4. A method as claimed in claim 3, including the step of calculating the power output of the power convertor (P_out), wherein P_in is calculated using the value of P_out and the average efficiency of the power converter (η

).

5. A method as claimed in claim 1, wherein the step of calculating I_mains includes using the power factor for the power converter.

6. A method as claimed in claim 1, wherein the steps of measuring V_bat and I_bat are undertaken by a measurement device associated with the battery.

7. A method as claimed in claim 6, wherein the measurement device is arranged to communicate V_bat and I_bat wirelessly.

8. A method as claimed in claim 1, wherein the calculation steps are carried out by a control module associated with the power converter.

9. A method as claimed in claim 8, wherein the control module is arranged to receive the measurements of V_bat and I_bat wirelessly.

10. A battery charger, the battery charger comprising a master controller and a plurality of power modules, each power module comprising a power converter and being configured to draw electrical power from a mains power source and supply electrical power to a battery, wherein the master controller is arranged to determine the current being drawn by the power modules during a battery charging process as set out with regards to the method as claimed in claim 1.

11. A method of charging a battery, comprising the steps of:

connecting a battery to a battery charger,

controlling the power supplied to the battery by the battery charger,

wherein the power drawn by the battery charger is limited to a maximum level and the power supplied to the battery by the battery charger is controlled in dependence on this maximum level, and the power being drawn by the battery charger is calculated by monitoring the power being supplied to the battery.