APPARATUS FOR CONTROLLING A CASCADED HYBRID CONSTRUCTION MACHINE SYSTEM AND A METHOD THEREFOR

• US 20150159346A1
• Filed: 06/08/2012
• Published: 06/11/2015
• Est. Priority Date: 06/08/2012
• Status: Active Grant

• Current Assignee: Volvo Construction Equipment AB (Volvo AB)
• Original Assignee: Volvo Construction Equipment AB (Volvo AB)
• Inventors: Kim, Chong-Chul
• Granted Patent: US 9,725,880 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B60K 6/46 Series type
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: B60W 20/50 Control strategies for responding to system failures, e.g. for fault diagnosis, failsafe operation or limp mode
• CPC Class Codes: B60W 2300/17 Construction vehicles, e.g. graders, excavators
• CPC Class Codes: B60W 2510/244 Charge state
• CPC Class Codes: B60W 2710/248 Current for loading or unloading
• CPC Class Codes: B60W 2710/305 target power to auxiliaries
• 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: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles
• CPC Class Codes: Y10S 903/903 having energy storing means, e.g. battery, capacitor

Abstract

The present invention relates to an apparatus for controlling a cascaded hybrid construction machine system and a method therefor, which apparatus includes: a control part for controlling an electric motor for driving an actuator differently according to whether or not the actuator performs a recovery action and whether or not an energy storage device can be recharged; and a motor driver for driving or stopping the electric motor by switching under the control of the control unit, wherein when the actuator performs a recovery action for both the overcharged state and the failure state of the energy storage device, the motor for driving the actuator is temporarily stopped by the switching of the motor driver so as to restrain the recovery energy generated, thus protecting the hybrid power source system and keeping the operator safe as well as resolving the problem of the working time being increased due to the system'"'"'s shutting off.

Claims

1. An apparatus for controlling a series hybrid construction machine system, comprising:

a control unit configured to differently control an electric motor that drives an actuator based on a result of determining whether the actuator of the construction machine performs a regenerative operation and whether an energy storage device is in an unchargeable state; and

a motor driver switched under the control of the control unit and configured to drive or stop the electric motor.

2. The apparatus according to claim 1, wherein the control unit comprises:

a first determination module configured to determine whether the actuator of the construction machine performs the regenerative operation based on a value obtained by converting a manipulation value of a joystick into a digital value;

a second determination module configured to determine whether the energy storage device is in the unchargeable state based on an SOC (State of Charge) value obtained from the energy storage device; and

a first control module 103 configured to control the motor driver to stop the electric motor that drives the actuator if it is determined that the actuator of the construction machine performs the regenerative operation and the energy storage device is in the unchargeable state as a result of determination by the first and second determination modules.

3. The apparatus according to claim 2, wherein the second determination module determines that the energy storage device is in the unchargeable state if the SOC value acquired from the energy storage device is equal to or larger than 1 (fully charged state) or the SOC value is not determined to be a constant value (failed state).

4. The apparatus according to claim 2, wherein the control unit further comprises a second control module configured to perform a discharge priority control of the energy storage device according to a discharge priority mode that is set after the stop of the electric motor.

5. A method for controlling a series hybrid construction machine system comprising a control unit configured to control an electric motor and a motor driver configured to drive or stop the electric motor, the method comprising:

a first determination step of determining whether an actuator of the construction machine performs a regenerative operation based on a value obtained by converting a manipulation value of a joystick into a digital value;

a second determination step of determining whether an energy storage device is in an unchargeable state based on an SOC (State of Charge) value obtained from the energy storage device; and

a first control step of controlling the motor driver to stop the electric motor that drives the actuator if it is determined that the actuator of the construction machine performs the regenerative operation and the energy storage device is in the unchargeable state as a result of determination by first and second determination steps.

6. The method according to claim 5, wherein the second determination step determines that the energy storage device is in the unchargeable state if the SOC value acquired from the energy storage device is equal to or larger than 1 (fully charged state) or the SOC value is not determined to be a constant value (failed state).

7. The method according to claim 5, further comprising a second control step of performing a discharge priority control of the energy storage device according to a discharge priority mode that is set after the stop of the electric motor.