HYBRID WORKING MACHINE AND SERVO CONTROL SYSTEM

• US 20110288711A1
• Filed: 01/27/2010
• Published: 11/24/2011
• Est. Priority Date: 01/29/2009
• Status: Active Grant

• Current Assignee: Sumitomo Heavy Industries Limited
• Original Assignee: Sumitomo Heavy Industries Limited
• Inventors: Yanagisawa, Makoto
• Granted Patent: US 9,008,875 B2
• Time in Patent Office: Days
• US Class Current: 701/22
• CPC Class Codes: B60L 50/15 with additional electric power supply with capacitors charged by engine-driven generators B60L50/40; with batteries charged by engine-driven generators B60L50/61
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 10/30 including control of auxiliary equipment, e.g. air-conditioning compressors or oil pumps
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B66C 13/18 Control systems or devices exclusively for rope, cable, or chain winding mechanisms B66D1/40
• CPC Class Codes: E02F 9/123 Drives or control devices specially adapted therefor E02F9/125 and E02F9/128 take precedence
• CPC Class Codes: E02F 9/2025 Particular purposes of control systems not otherwise provided for E02F3/16, E02F3/26, sub-groups of E02F3/43, E02F3/651, sub-groups of E02F3/84, E02F3/907, E02F5/145 take precedence
• CPC Class Codes: E02F 9/2058 Electric or electro-mechanical or mechanical control devices of vehicle sub-units for vehicles in general B60W
• CPC Class Codes: E02F 9/2075 of the hybrid type for vehicles in general B60W20/00
• CPC Class Codes: E02F 9/2091 Control of energy storage means for electrical energy, e.g. battery or capacitors energy recovery arrangements in hydraulic or pneumatic drives E02F9/2217
• CPC Class Codes: E02F 9/2217 with energy recovery arrangements, e.g. using accumulators, flywheels
• CPC Class Codes: E02F 9/2246 Control of prime movers, e.g. depending on the hydraulic load of work tools
• 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 10/72 Electric energy management in electromobility

Abstract

A hybrid working machine has an electric power accumulator charged by a generator driven by an engine and has an electrical load driven with electric power from the electric power accumulator. The hybrid working machine includes a direct-current bus electrically connected to the electric power accumulator, a voltage detector configured to detect the voltage of the direct-current bus, and a drive control part configured to control the driving of the generator based on the detected voltage value of the voltage detector. The drive control part is configured to control the generator based on the deviation between the detected voltage value and a voltage command value.

Claims

1. A hybrid working machine having an electric power accumulator charged by a generator driven by an engine and having an electrical load driven with electric power from the electric power accumulator, comprising:

a direct-current bus electrically connected to the electric power accumulator;

a voltage detector configured to detect a voltage of the direct-current bus; and

a drive control part configured to control driving of the generator based on a detected voltage value of the voltage detector,

wherein the drive control part is configured to control the generator based on a deviation between the detected voltage value and a voltage command value.

2. The hybrid working machine as claimed in claim 1, further comprising:

a converter configured to control charge and discharge of the electric power accumulator in accordance with a charge storage voltage request, the converter being provided between the electric power accumulator and the direct-current bus.

3. The hybrid working machine as claimed in claim 1, wherein the drive control part is configured to start controlling a voltage of the direct-current bus based on an abnormality signal generated in response to detection of an abnormality of a component of an electric power accumulation system including the electric power accumulator.

4. The hybrid working machine as claimed in claim 3, further comprising:

a current detector configured to detect a current from the generator and a current flowing through the generator,

wherein the drive control part is configured to switch torque control to voltage control in response to the generation of the abnormality signal, the torque control determining a torque command value so that a desired assist power is generated, the voltage control being based on the detected voltage value of the voltage detector configured to detect the voltage of the direct-current bus.

5. The hybrid working machine as claimed in claim 3, wherein the drive control part is configured to reduce an output of a hydraulic pump in response to the generation of the abnormality signal.

6. The hybrid working machine as claimed in claim 4, wherein the drive control part is configured to output a plurality of control gains including a voltage control gain and a current control gain.

7. A servo control system having an electric power accumulator charged by a generator driven by an engine and having an electrical load driven with electric power from the electric power accumulator, comprising:

a direct-current bus electrically connected to the electric power accumulator;

a voltage detector configured to detect a voltage of the direct-current bus; and

a drive control part configured to control driving of the generator based on a detected voltage value of the voltage detector,

wherein the drive control part is configured to control the generator based on a deviation between the detected voltage value and a voltage command value.