Power control system and method for adjusting an input power limit of a DC-DC voltage converter

• US 9,935,492 B2
• Filed: 08/29/2014
• Issued: 04/03/2018
• Est. Priority Date: 08/29/2014
• Status: Active Grant

• Current Assignee: LG Energy Solution Limited (LG Corporation)
• Original Assignee: LG Chem Limited (LG Corporation)
• Inventors: Smith, Alexander Jeffrey
• Primary Examiner(s): Tran, Thienvu
• Assistant Examiner(s): Stables, David M
• Application Number:
  US14/472,405
• Publication Number:
  US 20160064927A1
• Time in Patent Office: 1,313 Days
• Field of Search: None
• CPC Class Codes: B60L 2210/12 Buck converters
• CPC Class Codes: B60L 2210/42 Voltage source inverters
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 58/20 having different nominal voltages
• CPC Class Codes: H02J 2207/20 Charging or discharging characterised by the power electronics converter
• CPC Class Codes: H02J 7/00306 Overdischarge protection
• CPC Class Codes: H02J 7/345 using capacitors as storage or buffering devices
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/72 Electric energy management in electromobility

Abstract

A power control system for adjusting an input power limit of a DC-DC voltage converter is provided. The system includes a microprocessor that determines an amount of output power being output by a battery pack, an amount of available power in the battery pack, and an amount of input power being input to the DC-DC voltage converter. The microprocessor determines an amount of power being provided to the DC-AC inverter based on the amount of output power being output by the battery pack and the amount of input power being input to the DC-DC voltage converter. The microprocessor decreases the input power limit of the DC-DC voltage converter if a sum of the amount of power being provided to the DC-AC inverter and the amount of input power being input to the DC-DC voltage converter is greater than the amount of available power in the battery pack.

Claims

1. A power control system for adjusting an input power limit of a DC-DC voltage converter, comprising:

a battery pack having a positive electrode and a negative electrode, the battery pack adapted to generate a first voltage level between the positive electrode and the negative electrode of the battery pack;

a contactor having a contact, the contact being electrically coupled to the positive electrode of the battery pack when the contactor has a closed operational position, the contact being further electrically coupled to a first electrical node when the contactor has the closed operational position such that the first voltage level is received by the DC-DC voltage converter and the DC-AC inverter;

a first voltage sensor adapted to generate a first voltage signal indicative of the first voltage level between the positive electrode and the negative electrode of the battery pack;

a first current sensor adapted to generate a first current signal indicative of a total current level flowing from the battery pack;

a second current sensor being electrically coupled to and between the first electrical node and the DC-DC voltage converter;

the DC-DC voltage converter being further electrically coupled to the negative electrode of the battery pack, the second current sensor adapted to generate a second current signal indicative of a current level flowing through the DC-DC voltage converter;

a temperature sensor adapted to generate a temperature signal indicative of a temperature of the battery pack;

a microprocessor operably coupled to the first voltage sensor, the first current sensor, the second current sensor, and the temperature sensor;

the microprocessor being programmed to determine an amount of output power being output by the battery pack based on the first voltage signal and the first current signal;

the microprocessor being further programmed to determine an amount of available power in the battery pack based on the first current signal and the temperature signal;

the microprocessor being further programmed to determine an amount of input power being input to the DC-DC voltage converter from the battery pack based on the second current signal and the first voltage signal;

the microprocessor being further programmed to determine an amount of power being provided to the DC-AC inverter by subtracting the amount of input power being input to the DC-DC voltage converter from the amount of output power being output by the battery pack; and

the microprocessor being further programmed to decrease the input power limit of the DC-DC voltage converter if a sum of the amount of power being provided to the DC-AC inverter and the amount of input power being input to the DC-DC voltage converter is greater than the amount of available power in the battery pack.

2. The power control system of claim 1, wherein the microprocessor being further programmed to decrease the input power limit of the DC-DC voltage converter by setting the input power limit substantially equal to the amount of available power in the battery pack minus the amount of power being provided to the DC-AC inverter.

3. The power control system of claim 1, wherein the microprocessor being further programmed to generate a control signal to induce the DC-DC voltage converter to set the amount of input power being input to the DC-DC voltage converter substantially equal to the input power limit of the DC-DC voltage converter.

4. The power control system of claim 1, wherein the microprocessor being programmed to determine the amount of output power being output by the battery pack by:

determining a voltage value based on the first voltage signal;

determining a current value based on the first current signal; and

multiplying the voltage value by the current value to obtain the amount of output power being output by the battery pack.

5. The power control system of claim 1, wherein the microprocessor being programmed to determine the amount of input power being input to the DC-DC voltage converter from the battery pack by:

determining a voltage value based on the first voltage signal;

determining a current value based on the second current signal; and

multiplying the voltage value by the current value to obtain the amount of input power being input to the DC-DC voltage converter.

6. The power control system of claim 1, wherein the battery pack has first and second battery cells electrically coupled in series with one another, and the power control system further includes second and third voltage sensors electrically coupled to the first and second battery cells, respectively;

the second voltage sensor adapted to generate a second voltage signal indicative of a voltage level being output by the first battery cell;

the third voltage sensor adapted to generate a third voltage signal indicative of a voltage level being output by the second battery cell; and

the microprocessor being further programmed to determine the amount of available power in the battery pack based on the first current signal, the temperature signal, the second voltage signal, and the third voltage signal.

7. A method for adjusting an input power limit of a DC-DC voltage converter, comprising:

providing a power control system having a battery pack, the DC-DC voltage converter, a DC-AC inverter, a first voltage sensor, a first current sensor, a second current sensor, a temperature sensor, and a microprocessor;

the battery pack having a positive electrode and a negative electrode;

the microprocessor being operably coupled to the first voltage sensor, the first current sensor, the second current sensor, and the temperature sensor;

generating a first voltage level between the positive electrode and the negative electrode of the battery pack that is received by the DC-DC voltage converter and the DC-AC inverter;

generating a first voltage signal indicative of the first voltage level between the positive electrode and the negative electrode of the battery pack, utilizing the first voltage sensor;

generating a first current signal indicative of a total current level flowing from the battery pack, utilizing the first current sensor;

generating a second current signal indicative of a current level flowing from the battery pack to the DC-DC voltage converter, utilizing the second current sensor;

generating a temperature signal indicative of a temperature of the battery pack, utilizing the temperature sensor;

determining an amount of output power being output by the battery pack based on the first voltage signal and the first current signal, utilizing the microprocessor;

determining an amount of available power in the battery pack based on the first current signal and the temperature signal, utilizing the microprocessor;

determining an amount of input power being input to the DC-DC voltage converter from the battery pack based on the second current signal and the first voltage signal, utilizing the microprocessor;

determining an amount of power being provided to the DC-AC inverter b subtracting the amount of input power being input to the DC-DC voltage converter from the amount of output power being output by the battery pack, utilizing the microprocessor; and

decreasing the input power limit of the DC-DC voltage converter if a sum of the amount of power being provided to the DC-AC inverter and the amount of input power being input to the DC-DC voltage converter is greater than the amount of available power in the battery pack, utilizing the microprocessor.

8. The method of claim 7, wherein decreasing the input power limit of the DC-DC voltage converter comprises setting the input power limit substantially equal to the amount of available power in the battery pack minus the amount of power being provided to the DC-AC inverter, utilizing the microprocessor.

9. The method of claim 7, further comprising generating a control signal to induce the DC-DC voltage converter to set the amount of input power being input to the DC-DC voltage converter substantially equal to the input power limit of the DC-DC voltage converter, utilizing the microprocessor.

10. The method of claim 7, wherein determining the amount of output power being output by the battery pack comprises:

determining a voltage value based on the first voltage signal;

determining a current value based on the first current signal; and

multiplying the voltage value by the current value to obtain the amount of output power being output by the battery pack.

11. The method of claim 7, wherein determining the amount of input power being input to the DC-DC voltage converter from the battery pack comprises:

determining a voltage value based on the first voltage signal;

determining a current value based on the second current signal; and

multiplying the voltage value by the current value to obtain the amount of input power being input to the DC-DC voltage converter.

12. The method of claim 7, wherein the battery pack has first and second battery cells electrically coupled in series with one another, and the power control system further includes second and third voltage sensors electrically coupled to the first and second battery cells, respectively;

the method further comprising;

generating a second voltage signal indicative of a voltage level being output by the first battery cell, utilizing the second voltage sensor;

generating a third voltage signal indicative of a voltage level being output by the second battery cell, utilizing the third voltage sensor; and

determining the amount of available power in the battery pack based on the first current signal, the temperature signal, the second voltage signal, and the third voltage signal, utilizing the microprocessor.

13. A power control system for adjusting an input power limit of a DC-DC voltage converter, comprising:

a battery pack having a positive electrode and a negative electrode, the battery pack adapted to generate a first voltage level between the positive electrode and the negative electrode that is received by the DC-DC voltage converter and a DC-AC inverter;

a first voltage sensor adapted to generate a first voltage signal indicative of the first voltage level between the positive electrode and the negative electrode of the battery pack;

a first current sensor adapted to generate a first current signal indicative of a total current level flowing from the battery pack;

a second current sensor adapted to generate a second current signal indicative of a current level flowing from the battery pack to the DC-DC voltage converter;

a temperature sensor adapted to generate a temperature signal indicative of a temperature of the battery pack;

a microprocessor operably coupled to the first voltage sensor, the first current sensor, the second current sensor, and the temperature sensor;

the microprocessor being programmed to determine an amount of output power being output by the battery pack based on the first voltage signal and the first current signal;

the microprocessor being further programmed to determine an amount of available power in the battery pack based on the first current signal and the temperature signal;

the microprocessor being further programmed to determine an amount of input power being input to the DC-DC voltage converter based on the second current signal and the first voltage signal;

the microprocessor being further programmed to determine an amount of power being provided to the DC-AC inverter by subtracting the amount of input power being input to the DC-DC voltage converter from the amount of output power being output by the battery pack; and

the microprocessor being further programmed to decrease the input power limit of the DC-DC voltage converter if a sum of the amount of power being provided to the DC-AC inverter and the amount of input power being input to the DC-DC voltage converter is greater than the amount of available power in the battery pack.