Engine generator

• US 9,837,941 B2
• Filed: 05/30/2014
• Issued: 12/05/2017
• Est. Priority Date: 08/30/2013
• Status: Active Grant

• Current Assignee: Yanmar Power Technology Co., Ltd. (Yanmar Holdings Co., Ltd.)
• Original Assignee: Yanmar Company Limited (Yanmar Holdings Co., Ltd.)
• Inventors: Fujisawa, Toshinobu, Ogata, Kenji, Ise, Toshifumi, Miura, Yushi
• Primary Examiner(s): Patel, Tulsidas C
• Assistant Examiner(s): Reid, Jr., Charles
• Application Number:
  US14/914,112
• Publication Number:
  US 20160211784A1
• Time in Patent Office: 1,285 Days
• Field of Search: 322 89
• CPC Class Codes: H02J 7/1492 by means of controlling devices between the generator output and the battery
• CPC Class Codes: H02P 9/02 Details of the control
• CPC Class Codes: H02P 9/30 using semiconductor devices
• CPC Class Codes: H02P 9/48 Arrangements for obtaining a constant output value at varying speed of the generator, e.g. on vehicle H02P9/04 - H02P9/46 take precedence
• CPC Class Codes: Y02T 10/92 Energy efficient charging or discharging systems for batteries, ultracapacitors, supercapacitors or double-layer capacitors specially adapted for vehicles

Abstract

An engine generator detects a DC voltage in a path from a rectifier to an inverter in controlling charge/discharge, and makes a duty ratio in switching control of a charging conductor of a power storage device higher than a duty ratio in the switching control of a discharging conductor of the power storage device when the DC voltage is higher than a target voltage of the DC voltage, and makes the duty ratio in the switching control of the discharging conductor of the power storage device higher than the duty ratio in the switching control of the charging conductor of the power storage device when the DC voltage is lower than the target voltage.

Claims

1. An engine generator comprising:

an engine;

a generator configured to be driven by the engine;

a rectifier configured to rectify an output from the generator;

an inverter configured to convert a DC power from the rectifier into an AC power; and

a power storage device provided in parallel with the generator in a path from the rectifier to the inverter, the power storage device including a charging conductor and a discharging conductor,

wherein the engine generator controls conduction of the charging conductor and the discharging conductor so as to control charge/discharge of the power storage device,

wherein a DC voltage in the path from the rectifier to the inverter is detected in controlling the charge/discharge,

wherein a duty ratio in switching control of the charging conductor of the power storage device is set higher than a duty ratio in the switching control of the discharging conductor of the power storage device when the DC voltage is higher than a value obtained by adding a dead zone range to a target voltage of the DC voltage,

wherein the duty ratio in the switching control of the discharging conductor of the power storage device is set higher than the duty ratio in the switching control of the charging conductor of the power storage device when the DC voltage is lower than a value obtained by subtracting the dead zone range from the target voltage, and

wherein a load power is detected so as to change the dead zone to a value relative to the load power with a delay corresponding to a time constant not less than a predetermined value.

2. The engine generator according to claim 1, wherein, when a voltage of the power storage device is lower than a setting voltage in a state in which the DC voltage falls within the dead zone range, the switching control of the charging conductor of the power storage device is performed.

3. The engine generator according to claim 1, wherein the switching control of the discharging conductor or the charging conductor is performed so as to recover a voltage of the power storage device to a predetermined voltage.

4. The engine generator according to claim 2, wherein the switching control of the discharging conductor or the charging conductor is performed so as to recover a voltage of the power storage device to a predetermined voltage.