Power Control Unit

• US 20080084179A1
• Filed: 11/29/2007
• Published: 04/10/2008
• Est. Priority Date: 01/08/2003
• Status: Active Grant

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: SUZUKI, Masato, TOYOTA, Eiichi, KINOSHITA, Takuya, SHIMADA, Motomi, MIYAUCHI, Tsutomu, MIYAZAKI, Hideki, EMORI, Akihiko
• Granted Patent: US 7,692,430 B2
• Time in Patent Office: Days
• US Class Current: 320/109
• 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 means (101a, . . . ) has voltage measuring means (102a, . . . ) for measuring voltages of said storage means respectively, current measuring means (103a, . . . ) for measuring currents flowing through said storage means respectively, a status detecting means (104) for detecting the operating status of each storage means from values measured by said voltage measuring means and said current measuring means, and a charging/discharging controlling means (105) 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 storage means.

Claims

1. A tracked vehicle having a motor generator which assists the driving force of the engine, a plurality of storage means, and a power control apparatus which controls charging and discharging of said plurality of storage means;

wherein said power control apparatus comprises;

a voltage measuring means for measuring voltages of each of said storage means;

a current measuring means for measuring currents flowing through each of said storage means;

a status detecting means for detecting an operating status of each storage means, from values measured by said voltage measuring and current measuring means; and

a charging/discharging controlling means for controlling one of currents, voltages, and power according to said operating status of each storage means, to charge or discharge said storage means;

wherein,

said status detecting means calculates one of an internal impedance and open circuit voltage of each storage means; and

said charging/discharging controlling means calculates a permissible charging or discharging current value of each storage means from its internal impedance, open circuit voltage, preset maximum permissible voltage and minimum permissible voltage, calculates a sum of all currents flowing through said storage means to suppress a current over the calculated permissible charging or discharging current from flowing into or out of each of said storage means, and controls the charging or discharging current to maintain the total current below the calculated total current value.

2. A tracked vehicle according to claim 1, wherein said power control apparatus shows the service life and an expected replacement time of said each storage means calculated from said impedance of said each storage means.

3. A tracked vehicle according to claim 1, wherein said storage means is one of a lithium secondary cell, a nickel metal-hydride battery, a lead-acid battery and an electric double layer capacitor.

4. A tracked vehicle according to claim 1, wherein said motor generator is operable to start the engine, assist the driving force of the engine or generate power.

5. A tracked vehicle according to claim 1, wherein said tracked vehicle is a railway car or a monorail car.