Power generation system and control method

• US 7,482,710 B2
• Filed: 02/14/2005
• Issued: 01/27/2009
• Est. Priority Date: 03/22/2004
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Ichinose, Masaya, Futami, Motoo, Nakano, Susumu
• Primary Examiner(s): Sherry; Michael J
• Assistant Examiner(s): CAVALLARI, DANIEL J
• Application Number:
  US11/056,004
• Publication Number:
  US 20050206343A1
• Time in Patent Office: 1,443 Days
• Field of Search: 307/67, 290/18, 290/22, 290/1.A, 290/36.R, 244/53.A, 244/58, 322/22
• US Class Current: 307/67
• CPC Class Codes: H02J 9/08 requiring starting of a prime-mover

Abstract

A power generation system includes a first unit power generation system having a storage battery, a second unit power generation system having no storage battery and a controller, at a time of starting up of the power generation system, the controller first starts up the first unit power generation system and then starts up the second unit power generation system having no storage battery by supplying electric power generated by the first unit power generation system to the second unit power generation system.

Claims

1. A power generation system comprising a plurality of unit power generation systems each of which supplies electric power generated by its generator to a load via a power converter and a breaker, wherein:

a first unit power generation system includes a first power converter having a storage battery in its DC section, and

each of the other unit power generation systems includes other power converters having no storage battery in its DC section,

the power generation system further comprises a controller which first starts up the first unit power generation system using electric power generated by the first power converter, and then starts up the other unit power generation systems having no storage battery using electric power generated by the first unit power generation system which has already been started up, during a startup of the power generation system when an external power system has an abnormality or no external power is available, and

the controller executes AC voltage control of the first power converter while letting a charging and/or discharging unit provided to the storage battery execute DC voltage control of its power converter so as to suppress DC voltage fluctuations caused by variations in the load and maintain balance of electric power.

2. The power generation system according to claim 1, wherein the storage battery has a capacity capable of starting up the plurality of unit power generation systems at least once.

3. The power generation system according to claim 1, wherein:

the first unit power generation system includes a charging and/or discharging unit for charging and/or discharging the storage battery in the DC section of first power converter, and

the power generation system further comprises a controller which switches the system to an operation mode for reducing fuel supply and controls the storage battery charging and/or discharging unit of the first unit power generation system to maintain balance between generated power and power consumption of the load in case of outage of the power generation system.

4. The power generation system according to claim 3, wherein the storage battery has a capacity capable of starting up the plurality of unit power generation systems at least once.

5. The power generation system according to claim 1, wherein:

each unit power generation system includes a gas turbine generator, an AC/DC converter connected to an output side of the gas turbine generator, a DC/AC converter connected to a DC side of the AC/DC converter, and a breaker connected to an AC side of the DC/AC converter, and

the plurality of unit power generation systems are connected in parallel to be connected to a load and the external power system, and

the first unit power generation including the storage battery further includes the battery charging and/or discharging unit, and

the controller executes the AC voltage control of the AC side of the DC/AC converter of the first unit power generation system while letting the charging and/or discharging unit execute the DC voltage control so as to suppress DC voltage fluctuations caused by variations in the load and maintain balance of electric power.

6. The power generation system according to claim 5, wherein the storage battery has a capacity capable of starting up the plurality of unit power generation systems at least once.

7. A power generation system comprising:

a plurality of unit power generation systems for supplying electric power to a load,

each unit power generation system comprising a generator which supplies electric power, a power converter and a breaker,

a first one of the unit power generation systems further including a storage battery in a DC section of its power converter,

each other unit power generation system including no storage battery in a DC section of its power converter; and

a controller which starts up the plurality of unit power generation systems for supplying electric power to the load, wherein;

during a startup of the power generation system when an external power system has an abnormality or no external power is available, the controller;

(1) first starts up the first unit power generation system using electric power generated by the power converter having the storage battery of the first unit power generation system, and (2) then starts up each other unit power generation system using electric power generated by the first unit power generation system which has already been started, and

the controller executes AC voltage control of the first power converter while letting a charging and/or discharging unit provided to the storage battery execute DC voltage control of its power converter so as to suppress DC voltage fluctuations caused by variations in the load and maintain balance of electric power.