Inverter controlled generator set and method for controlling the same

• US 20050104377A1
• Filed: 10/21/2004
• Published: 05/19/2005
• Est. Priority Date: 10/31/2003
• Status: Active Grant

• Current Assignee: Kokusan Denki Company Limited (MAHLE-STIFTUNG GmbH)
• Original Assignee: Kokusan Denki Company Limited (MAHLE-STIFTUNG GmbH)
• Inventors: Nakagawa, Masanori, Yamamoto, Katsumi, Shinba, Kaoru, Sugisawa, Yoshihiro, Endou, Masahiko
• Granted Patent: US 7,157,885 B2
• Time in Patent Office: Days
• US Class Current: 290/40.A
• CPC Class Codes: H02P 9/04 Control effected upon non-electric prime mover and dependent upon electric output value of the generator

Abstract

A method for controlling an inverter controlled generator set which comprises a DC power source section having as a power source a generator driven by an engine and an inverter which converts an output of said DC power source section into an AC output, the method comprising a step of controlling a rotational speed of the engine so that the AC output suitable for driving a load is output from the inverter; wherein, after the engine is started, the rotational speed of the engine is controlled by a constant speed control mode for maintaining the rotational speed of the engine at a set rotational speed, and the rotational speed of the engine is increased to the set rotational speed; and wherein an operation of the inverter is started after the rotational speed of the engine reaches the set rotational speed.

Claims

1. A method for controlling an inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source; and

an inverter which converts an DC output of said DC power source section into an AC output that is supplied to a load, and said method comprising a step of controlling a rotational speed of said engine so that the AC output suitable for driving said load is output from said inverter,

wherein, after the engine is started, the rotational speed of said engine is controlled by a constant speed control mode for maintaining the rotational speed of said engine at a set rotational speed, until the rotational speed of the engine is increased to the set rotational speed, and

wherein an operation of said inverter is started after the rotational speed of said engine reaches said set rotational speed.

2. A method for controlling an inverter controlled generator set as set forth in claim 1, wherein said set rotational speed is set higher than a rotational speed at which said inverter starts generating a rated output.

3. A method for controlling an inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source; and

an inverter which converts an DC output of said DC power source section into an AC output that is supplied to a load, and said method comprising a step of controlling a rotational speed of said engine so that the AC output suitable for driving said load is output from said inverter,

wherein, after the engine is started, the rotational speed of said engine is controlled by a constant speed control mode for maintaining the rotational speed of said engine at a set rotational speed, until the rotational speed of the engine is increased to the set rotational speed, and then an operation of said inverter is started, and

wherein, when a predetermined control mode proceeding requirement is satisfied, a control mode of said engine is switched to a constant voltage control mode for controlling the rotational speed of said engine so as to maintain an output voltage of said DC power source section at a set value.

4. A method for controlling an inverter controlled generator set as set forth in claim 3, wherein said set rotational speed is set higher than a rotational speed at which said inverter starts generating a rated output.

5. A method for controlling an inverter controlled generator set as set forth in claim 3, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode.

6. A method for controlling an inverter controlled generator set as set forth in claim 3, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode and that the output voltage of said generator becomes stable.

7. A method for controlling an inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source; and

an inverter which converts an DC output of said DC power source section into an AC output that is supplied to a load, and said method comprising a step of controlling a rotational speed of said engine so that the AC output suitable for driving said load is output from said inverter,

wherein, when said engine is in a state of requiring a warm-up at the start of the engine, the rotational speed of the engine is controlled by a constant speed control mode for maintaining the rotational speed of said engine at a set rotational speed, until the rotational speed of the engine is increased to the set rotational speed, and

wherein an operation of said inverter is started after the rotational speed of said engine reaches said set rotational speed.

8. A method for controlling an inverter controlled generator set as set forth in claim 7, wherein said set rotational speed is set higher than a rotational speed at which said inverter starts generating a rated output.

9. A method for controlling an inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source; and

an inverter which converts an DC output of said DC power source section into an AC output that is supplied to a load, and said method comprising a step of controlling a rotational speed of said engine so that the AC output suitable for driving said load is output from said inverter,

wherein, when said engine is in a state of requiring a warm-up at the start of the engine, the rotational speed of the engine is controlled by a constant speed control mode for maintaining the rotational speed of said engine at a set rotational speed, until the rotational speed of the engine is increased to the set rotational speed, and an operation of said inverter is started after the rotational speed of said engine reaches said set rotational speed,

wherein, when a predetermined control mode proceeding requirement is satisfied, a control mode of said engine is switched to a constant voltage control mode for controlling the rotational speed of said engine so as to maintain an output voltage of said DC power source section at a set value, and

wherein, when said load is input while said engine performs the warm-up, the rotational speed of the engine is controlled by said constant speed control mode even if said control mode proceeding requirement is fulfilled.

10. A method for controlling an inverter controlled generator set as set forth in claim 9, wherein said set rotational speed is set higher than a rotational speed at which said inverter starts generating a rated output.

11. A method for controlling an inverter controlled generator set as set forth in claim 9, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode.

12. A method for controlling an inverter controlled generator set as set forth in claim 9, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode and that the output voltage of said generator becomes stable.

13. An inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source to generate a DC output;

an inverter into which the output of said DC power source section is input;

inverter control means for controlling said inverter so as to output a desired AC voltage from said inverter; and

rotational speed control means for controlling a rotational speed of said engine so that an AC output suitable for driving a load of said inverter is output from said inverter,

wherein said rotational speed control means comprises;

constant rotational speed control means for controlling the rotational speed of said engine so as to maintain the rotational speed of the engine at a set rotational speed;

constant voltage control means for controlling the rotational speed of said engine so that an output voltage of said DC power source section is kept at a set value; and

control mode switching means for switching a control mode of the engine so that the control mode is set to a constant speed control mode for controlling the rotational speed by said constant rotational speed control means, until a predetermined control mode proceeding requirement is satisfied after starting said engine, and so that the control mode of the engine is switched to a constant voltage control mode for controlling the rotational speed by said constant voltage control means when said control mode proceeding requirement is satisfied, and

wherein said inverter control means is comprised so as to start control of said inverter when said rotational speed of the engine reaches said set rotational speed after starting the engine.

14. An inverter controlled generator set as set forth in claim 13, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode.

15. An inverter controlled generator set which comprises:

an engine;

a DC power source section having a generator driven by said engine as a power source to generate a DC output;

an inverter into which the output of said DC power source section is input;

inverter control means for controlling said inverter so as to output a desired AC voltage from said inverter; and

rotational speed control means for controlling a rotational speed of said engine so that an AC output suitable for driving a load of said inverter is output from said inverter,

wherein said rotational speed control means comprises;

constant rotational speed control means for controlling the rotational speed of said engine so as to maintain a set rotational speed;

constant voltage control means for controlling the rotational speed of said engine so that an output voltage of said DC power source section is kept at a set value; and

control mode switching means for switching a control mode of the engine so that the control mode is set to a constant speed control mode for controlling the rotational speed by said constant rotational speed control means, until a predetermined control mode proceeding requirement is satisfied after starting said engine in the state where said engine requires a warm-up at starting the engine, and so that the control mode of the engine is switched to a constant voltage control mode for controlling the rotational speed by said constant voltage control means when said control mode proceeding requirement is satisfied and when said engine does not require the warm-up at starting, and

wherein said inverter control means is comprised so as to start control of said inverter when said rotational speed of the engine reaches said set rotational speed after starting the engine.

16. An inverter controlled generator set as set forth in claim 15, wherein said control mode switching means is constituted so that, when said load is input while said engine performs the warm-up, said control mode for the rotational speed of the engine is set as said constant speed control mode even if said control mode proceeding requirement is fulfilled.

17. An inverter controlled generator set as set forth in claim 15, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode.

18. An inverter controlled generator set as set forth in claim 15, wherein said control mode proceeding requirement is that a predetermined time is passed after starting said constant speed control mode and that the output voltage of said generator becomes stable.