Power control unit

• US 7,692,430 B2
• Filed: 11/29/2007
• Issued: 04/06/2010
• Est. Priority Date: 01/08/2003
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Suzuki, Masato, Shimada, Motomi, Miyauchi, Tsutomu, Emori, Akihiko, Miyazaki, Hideki, Toyota, Eiichi, Kinoshita, Takuya
• Primary Examiner(s): NGUYEN, HOAI AN D
• Application Number:
  US11/947,318
• Publication Number:
  US 20080084179A1
• Time in Patent Office: 859 Days
• Field of Search: 324/413, 324/410, 324/405, 324/403, 324426-428, 324430-434, 324/522, 324/678, 324/87, 324/382, 320/103, 320/104, 320/119, 320/126, 320/132, 320/134, 320/136, 320/149, 320/106
• US Class Current: 324/430
• CPC Class Codes: G01R 31/389 Measuring internal impedance, internal conductance or related variables
• CPC Class Codes: H02J 7/0013 acting upon several batteries simultaneously or sequentially H02J7/1423 takes precedence
• CPC Class Codes: H02J 7/0016 using shunting, discharge or bypass circuits
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 30/00 Transportation of goods or passengers via railways, e.g. energy recovery or reducing air resistance

Abstract

A power control apparatus for controlling charging and discharging of a plurality of storage devices, including a voltage measuring device for measuring voltages of the storage devices, a current measuring device for measuring currents flowing through the storage devices, a status detecting device for detecting the operating status of each of the storage devices from values measured by the voltage measuring device and the current measuring device, and a charging/discharging controlling device for controlling currents, voltages, or power according to the operating status of each storage device detected by the status detecting device to charge or discharge the storage devices.

Claims

1. A power control apparatus for controlling charging and discharging of a plurality of storage means, comprising

a voltage measuring means for measuring voltages of at least one of said plural storage means;

a current measuring means for measuring a current flowing through at least one of said plural storage means;

a status detecting means for detecting the operating status of at least one of said plural storage means from values measured by said voltage measuring means and said current measuring means; and

a charging/discharging controlling means for controlling currents, voltages, or power according to the operating status of each storage means detected by said status detecting means, to charge or discharge said plural storage means,

wherein said status detecting means calculates the internal impedance or open circuit voltage of at least one of said plural storage means, and

said charging/discharging controlling means calculates the permissible charging or discharging current value of at least one of said plural storage means from its internal impedance or open circuit voltage, preset maximum permissible voltage, and minimum permissible voltage, and controls the charging or discharging current so that the current above the calculated permissible charging or discharging current may not flow into or out of at least one of said plural storage means.

2. The power control apparatus of claim 1, wherein said status detecting means calculates the internal impedance or open circuit voltage of each of said plural storage means and the charging/discharging controlling means controls charging/discharging currents, voltages, or power of said plural storage means according to impedances or open circuit voltages thereof.

3. The power control apparatus of claim 1, wherein said status detecting means calculates the charging status of each storage means and determines the maximum or minimum of the calculated charging states, and said charging/discharging controlling means controls the charging current, voltage, or power by the maximum charging status value and controls the discharging current, voltage, or power by the minimum charging status value.

4. The power control apparatus of claim 1, wherein said power control apparatus further comprises a switch means which selectively breaks or makes a connection between said charging/discharging controlling means and any storage means, and said charging/discharging controlling means checks the on/off status of said switch means and controls the current, voltage or power according to the detected on/off status of said switch means and the status of each of said plural storage means to discharge or charge said plural storage means.

5. The power control apparatus of claim 4, wherein said status detecting means calculates the internal impedance or open circuit voltage of each storage means and said charging/discharging controlling means controls charging/discharging currents, voltages, or power of said storage means according to the impedances or open circuit voltages thereof.

6. The power control apparatus of claim 4, wherein said status detecting means calculates the charging status of each storage means and determines the maximum or minimum of the calculated charging states, and said charging/discharging controlling means controls the charging current, voltage, or power by the maximum charging status value and controls the discharging current, voltage, or power by the minimum charging status value.

7. The power control apparatus of claim 1, further comprising a load and a means selected from a group of a commercial power supply, a solar energy generator, a micro gas turbine generator and a fuel cell to supply power to said load, wherein said power control apparatus supplies power to said load or said commercial power supply and uses power from said commercial power supply, a solar energy generator, a micro gas turbine generator or a fuel cell as a charging power.

8. The power control apparatus of claim 1, wherein said storage means supply power to an electric motor which drives vehicle wheels and are charged by power from the outside of a vehicle or power from said electric motor when said motor is used as a power generator.

9. The power control apparatus of claim 1, wherein said storage means supply power to an electric motor which drives vehicle wheels and are charged by power generated by a dynamo-electric generator which is driven by a internal combustion engine on a vehicle or power from said electric motor when said motor is used as a power generator.