CABLE COMPENSATION BY ZERO-CROSSING COMPENSATION CURRENT AND RESISTOR

• US 20150194836A1
• Filed: 01/08/2014
• Published: 07/09/2015
• Est. Priority Date: 01/08/2014
• Status: Active Grant

• Current Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Original Assignee: Infineon Technologies Austria Ag (Infineon Technologies AG)
• Inventors: Teo, Yong Siang, Lim, Kok Kee
• Granted Patent: US 9,397,517 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60L 53/122 Circuits or methods for driving the primary coil, e.g. supplying electric power to the coil
• CPC Class Codes: B60L 53/38 specially adapted for charging by inductive energy transfer
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 50/00 Circuit arrangements or systems for wireless supply or distribution of electric power
• CPC Class Codes: H02J 50/90 involving detection or optimisation of position, e.g. alignment
• CPC Class Codes: H02J 7/00 Circuit arrangements for charging or depolarising batteries or for supplying loads from batteries
• CPC Class Codes: H02J 7/00302 Overcharge protection
• CPC Class Codes: H02J 7/00712 the cycle being controlled or terminated in response to electric parameters
• CPC Class Codes: H02M 3/33507 with automatic control of the output voltage or current, e.g. flyback converters H02M3/33561, H02M3/33569 take precedence
• CPC Class Codes: Y02B 40/00 Technologies aiming at improving the efficiency of home appliances, e.g. induction cooking or efficient technologies for refrigerators, freezers or dish washers
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/14 Plug-in electric vehicles

Abstract

Methods, devices, and circuits are disclosed delivering a first level of output voltage to a rechargeable battery from a battery charger, the rechargeable battery is coupled to the battery charger by a charging cable. The methods, device, and circuits may further be disclosed applying, in response to an indication of an altered output voltage, a compensation current to one or more elements of the battery charger including a zero crossing (ZC) pin and a selected resistor, the selected resistor is defined by the charging cable coupling the battery charger to the rechargeable battery, and applying the compensation current to the ZC pin and the selected resistor causes an adjustment of the output voltage from the first level of output voltage to a second level of output voltage corresponding to the voltage drop from the impedance of the selected charging cable.

Claims

1. A method comprising:

delivering a first level of output voltage to a rechargeable battery from a battery charger, wherein the rechargeable battery is coupled to the battery charger by a charging cable; and

applying, in response to an indication of an altered output voltage, a compensation current to one or more elements of the battery charger including a zero crossing (ZC) pin and a selected resistor, wherein the selected resistor is defined based on the charging cable coupling the battery charger to the rechargeable battery;

wherein applying the compensation current to the ZC pin and the selected resistor causes an adjustment of the output voltage from the first level of output voltage to a second level of output voltage corresponding to the voltage drop from the impedance of the selected charging cable.

2. The method of claim 1, wherein the indication of the altered output voltage further comprises:

operating a primary-side-regulation (PSR) controller, wherein the PSR controller controls the power supplied to the rechargeable battery, the method of controlling the power supplied to the rechargeable battery comprising;

sampling a zero crossing (ZC) voltage at a ZC pin of the PSR controller to generate a sampled ZC output voltage signal;

generating an output voltage of a constant voltage control (CVC) module as a function of the sampled ZC output voltage signal;

sampling an output voltage of the battery charger to generate a sampled output voltage signal;

generating a compensation current by a compensation current control module at the ZC pin as a function of the sampled output voltage,

wherein the compensation current and the resistor are configured to provide an offset voltage to the ZC pin to offset a voltage drop due to the impedance of the selected charging cable; and

comparing the sampled output voltage signal to a sense voltage signal indicative of the inductor current on a primary winding of the transformer to control the battery charger and the charging of the rechargeable battery.

3. The method of claim 1, wherein the selected resistor is a first resistor coupled to a second resistor in parallel with a capacitor.

4. The method of claim 2, wherein the compensation current control module further comprises limiting the sampled output voltage by a maximum current limit module, wherein limiting the sampled output voltage limits the compensation current.

5. The method of claim 2, wherein the sampled output voltage is an output voltage of the CVC module.

6. The method of claim 2, wherein the sampled output voltage is a peak sense voltage at a current sense (CS) pin of the PSR controller indicative of the inductor current through the primary winding of the transformer.

7. The method of claim 2, wherein the ZC sample module is a sample-and-hold module that samples and holds the voltage detected at the ZC pin.

8. The method of claim 2, wherein the CVC module is a proportional-integral (PI) controller, and wherein the PI controller is configured to generate a PI controller output voltage as a function of the sampled ZC output voltage signal from the ZC sample module.

9. A battery charging device comprising:

a transformer including a primary winding and an auxiliary winding;

a primary-side-regulation (PSR) controller including;

a zero crossing (ZC) pin;

a ZC sample module, wherein the ZC sample module samples a ZC voltage at the ZC pin;

a constant voltage control (CVC) module, wherein the PSR controller delivers an output voltage to a rechargeable battery based on the sampled ZC voltage at the ZC pin; and

a compensation current control module comprising;

a sample-and-hold (S/H) module, wherein the S/H module samples and holds an output voltage;

a voltage to current generator, wherein the voltage to current generator is configured to generate a compensation current as a function of the sampled output voltage; and

wherein the compensation current control module is coupled to the ZC pin; and

an adjustable offset voltage circuit including;

a selected resistor, wherein the resistor is selected based on a selected charging cable, wherein the resistor is releasably coupled to the ZC pin and the auxiliary winding, and wherein an offset voltage at the ZC pin is generated by the compensation current and the resistor corresponding to the voltage drop due to cable impedance of the selected charging cable.

10. The battery charger of claim 9, wherein the compensation current control module further comprises a maximum current limit module, wherein the maximum current limit module limits the compensation current.

11. The battery charger of claim 9, wherein the sampled output voltage of the compensation current control module is an output voltage of the CVC module.

12. The battery charger of claim 9, wherein the sampled output voltage of the compensation current control module is a peak sense voltage at a current sense (CS) pin of the PSR controller indicative of the inductor current through the primary winding of the transformer.

13. The battery charger of claim 9, wherein the selected resistor of the adjustable offset voltage circuit is a first resistor coupled to a second resistor in parallel with a capacitor.

14. The battery charger of claim 9, wherein the ZC sample module is a sample-and-hold module that samples and holds the voltage at the zero crossing pin.

15. The battery charger of claim 9, wherein the CVC module is a proportional-integral (PI) controller, and wherein the PI controller is configured to generate a PI controller output voltage as a function of the sampled ZC output voltage signal from the ZC sample module.

16. The battery charger of claim 9, wherein the PSR controller further comprising a zero crossing detector.

17. The battery charger of claim 9, wherein the PSR controller further comprising an oscillator.

18. A circuit comprising:

a transformer including a primary winding and an auxiliary winding;

a primary-side-regulation (PSR) controller including;

a zero crossing (ZC) pin;

a ZC sample module, wherein the ZC sample module samples a ZC voltage at the ZC pin;

a constant voltage control (CVC) module, wherein the PSR controller delivers an output voltage to a rechargeable battery based on the sampled ZC voltage at the ZC pin; and

a compensation current control module comprising;

a sample-and-hold (S/H) module, wherein the S/H module samples and holds the output voltage;

a voltage to current generator, wherein the voltage to current generator is configured to generate a compensation current as a function of the sampled output voltage; and

wherein the compensation current control module is coupled to the ZC pin; and

an adjustable offset voltage circuit including;

a selected resistor, wherein the resistor is selected based on a selected charging cable, wherein the resistor is releasably coupled to the ZC pin and the auxiliary winding, and wherein an offset voltage at the ZC pin is generated by the compensation current and the resistor corresponding to the voltage drop due to cable impedance of the selected charging cable.

19. The circuit of claim 18, wherein the PSR controller further comprising:

a comparator that is configured to control a transistor and charge the recharegable battery by the selected charging cable,

wherein the comparator comprises a first input node and a second input node, wherein the comparator is configured to generate a control signal at an output node of the comparator by comparing an output voltage of the CVC module at the first input node of the comparator to a sense voltage signal indicative of inductor current flowing through a primary winding of the transformer at the second input node of the comparator, wherein the comparator is configured to generate at the output node of the comparator the control signal to control switching of a transistor and generation of the output voltage, and wherein the comparator develops a regulated output voltage to control the charging of the rechargeable battery.

20. The circuit of claim 18, wherein the selected resistor of the adjustable offset voltage circuit is a first resistor coupled to a second resistor in parallel with a capacitor.