Apparatus and method for controlling charge and discharge of secondary battery

Patent metadata

Field	Value
Publication number	US-10236703-B2
Application number	US-201514593143-A
Country	US
Kind code	B2
Filing date	Jan 9, 2015
Priority date	Nov 13, 2012
Publication date	Mar 19, 2019
Grant date	Mar 19, 2019

Abstract

Disclosed is an apparatus and method for controlling charge and discharge of a secondary battery. The apparatus for controlling charge and discharge of the secondary battery includes the power control unit calculates an amount of discharging power of the secondary battery, and when voltage value of the secondary battery is less than a preset reference voltage value, outputs a compensation charge control signal to charge the secondary battery with an amount of charging power obtained by adding an amount of power compensation to the calculated amount of discharging power. According to the present disclosure, the problem of a charge amount of the secondary battery reducing gradually with increasing charge and discharge cycles of the secondary battery may be prevented by compensating for the charge amount of the secondary battery.

First claim

What is claimed is:

1. An apparatus for controlling charge and discharge of a secondary battery, the apparatus comprising:
a sensing unit to measure a voltage of the secondary battery, measure a current of the secondary battery during charging or discharging of the secondary battery and output a voltage value and a current value corresponding to the measured voltage and current, respectively, the secondary battery being included in a power storage unit operable to store a certain amount of power generated by a power generation unit including a generator configured to generate power by new renewal energy, or to discharge stored power; and
a power control unit configured to:
output a charge control signal to store the certain amount of power generated by the power generation unit in the power storage unit and supply residual power to a power grid, or a discharge control signal to discharge the power stored in the power storage unit and supply the same to the power grid together with the power generated by the power generation unit,
measure a state of charge (SOC) of the secondary battery using the voltage value and the current value of the secondary battery measured by, and received from, the sensing unit,
calculate an amount of discharging power of the secondary battery using the voltage value or the current value measured by the sensing unit during the discharging of the secondary battery, and
when the voltage value of the secondary battery is less than a preset reference voltage value, output a compensation charge control signal that is different from the charge control signal and the discharge control signal and that is for controlling a charge amount of the secondary battery in consideration of the SOC of the secondary battery, to charge the secondary battery with an amount of charging power obtained by adding, to the calculated amount of discharged power, an amount of power compensation which is based on a preset ratio to a calculated expected power generation amount,

wherein the preset ratio for calculating the amount of power compensation increases with an increasing number of charge/discharge cycles of the secondary battery due to an increased energy loss of the secondary battery from an increased internal resistance of the secondary battery.

2. The apparatus for controlling charge and discharge of the secondary battery according to claim 1 , wherein the power generation unit generates power by at least one power generation method selected from sunlight power generation, solar heat power generation, wind power generation, geothermal heat power generation, hydroelectric power generation, tidal power generation, wave power generation, and power generation by ocean temperature difference.

3. The apparatus for controlling charge and discharge of the secondary battery according to claim 1 , further comprising:
a rotations per minute (RPM) measuring device to measure a rotation rate of the generator included in the power generation unit and output a generator rotation rate value,
wherein the power control unit determines the amount of power compensation based on an expected power generation amount of the power generation unit calculated using the generator rotation rate value.

4. The apparatus for controlling charge and discharge of the secondary battery according to claim 3 , wherein the amount of power compensation is preset based on the calculated expected power generation amount.

5. The apparatus for controlling charge and discharge of the secondary battery according to claim 1 , further comprising:
a power measuring device to measure an amount of power generated by the power generation unit and output a power generation amount value,
wherein the power control unit determines the amount of power compensation based on the power generation amount value.

6. The apparatus for controlling charge and discharge of the secondary battery according to claim 5 , wherein the amount of power compensation is preset based on the power generation amount value.

7. The apparatus for controlling charge and discharge of the secondary battery according to claim 1 , wherein the amount of power compensation is preset based on the calculated amount of discharging power.

8. The apparatus for controlling charge and discharge of the secondary battery according to claim 1 , further comprising:
a memory unit to store the reference voltage value.

9. A new renewable energy generation system comprising:
the apparatus for controlling charge and discharge of the secondary battery defined in claim 1 ,
the power generation unit including the generator configured to generate power by new renewal energy; and
the power storage unit to store power generated by the power generation unit or discharge stored power.

10. The new renewable energy generation system according to claim 9 , further comprising:
a power conversion unit to convert the power generated by the power generation unit or the power outputted from the power storage unit to a required voltage value, a required current value, a required frequency, or a required waveform.

11. A method of controlling charge and discharge of a secondary battery for quality stabilization of power in the supply of power generated by new renewal energy to a power grid, the secondary battery being included in a power storage unit operable to store a certain amount of power generated by a power generation unit or discharge stored power, the method comprising:
measuring, by a sensing unit, a voltage of the secondary battery;
measuring, by the sensing unit, a current of the secondary battery during charging or discharging of the secondary battery;
outputting, by the sensing unit, a voltage value and a current value corresponding to the measured voltage and current, respectively;
outputting, by a power control unit, a charge control signal to store the certain amount of power generated by the power generation unit in the power storage unit and supply residual power to a power grid, or a discharge control signal to discharge the power stored in the power storage unit and supply the same to the power grid together with the power generated by the power generation unit,
measuring, by the power control unit, a state of charge (SOC) of the secondary battery using the voltage value and the current value of the secondary battery measured by, and received from, the sensing unit;
calculating, by the power control unit, an amount of discharging power of the secondary battery using the voltage value or the current value measured by the sensing unit during the discharging of the secondary battery; and
outputting, by the power control unit, a compensation charge control signal that is different from the charge control signal and the discharge control signal and that is for controlling a charge amount of the secondary battery in consideration of the SOC of the secondary battery, to charge the secondary battery with an amount of charging power obtained by adding, to the calculated amount of discharged power, an amount of power compensation which is based on a preset ratio to a calculated expected power generation amount, when the received voltage value of the secondary battery is less than a preset reference voltage value,
wherein the preset ratio for calculating the amount of power compensation increases with an increasing number of charge/discharge cycles of the secondary battery due to an increased energy loss of the secondary battery from an increased internal resistance of the secondary battery.

Assignees

• Lg Chemical Ltd

Inventors

• Chung Dae-Sik
• Cho Tae-Shin

Classifications

• H02J4/00

  Circuit arrangements for mains or distribution networks not specified as AC or DC; Circuit arrangements for mains or distribution networks combining AC and DC sections or sub-networks (arrangements using intermediate DC-AC-DC conversion H02J1/002; arrangements using high-voltage DC [HVDC] links H02J3/36) · CPC title

• H02J3/381

  Dispersed generators · CPC title

• Y02E70/30

  Systems combining energy storage with energy generation of non-fossil origin · CPC title

• H02J2101/22

  Solar energy · CPC title

• H02J2101/20

  Dispersed power generation using renewable energy sources · CPC title