Microgrid startup method and startup program

Patent metadata

Field	Value
Publication number	US-12237681-B2
Application number	US-202118263110-A
Country	US
Kind code	B2
Filing date	Feb 19, 2021
Priority date	Feb 19, 2021
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A startup method and startup program for microgrid that enable to stably start up the microgrid without producing frequency fluctuation is provided. An embodiment of the present disclosure is a startup method for microgrid configured by a plurality of inverter power supplies independently sharing a load and divided into a master that starts up first and a slave that starts up secondly and later, the startup method comprising: a master initial startup step of initially starting up the master in a CVCF mode; a slave initial startup step of initially starting up the slave in a grid interconnection mode; and a control mode changing step of the master and the slave changing control modes thereof when output fluctuation of the master and the slave becomes a predetermined threshold or less or when the master and the slave or other inverter power supplies become a predetermined operation state while output voltage of said master and said slave becomes a predetermined threshold or less.

First claim

The invention claimed is:

1. A startup method of microgrid configured by a plurality of inverter power supplies independently sharing a load and divided into a master that starts up first and a slave that starts up secondly and later, the startup method comprising:
a master initial startup step of initially starting up the master in a CVCF mode;
a slave initial startup step of initially starting up the slave in a grid interconnection mode; and
a control mode changing step of the master and the slave changing control modes thereof when output fluctuation of the master and the slave becomes a predetermined threshold or less or when the master and the slave or other inverter power supplies become a predetermined operation state while output voltage of said master and said slave becomes a predetermined threshold or less.

2. The startup method of microgrid according to claim 1 , wherein the control mode changing step is a control mode changing step to a droop mode of changing the CVCF mode of the master to the droop mode of the master and changing the grid interconnection mode of the slave to the droop mode of the slave, and includes a droop characteristic enablement step of enabling droop characteristics of the master and the slave and a load sharing step of updating a command value from outside the microgrid and sharing a load by external control.

3. The startup method of microgrid according to claim 2 , wherein the control mode changing step to droop mode executes the droop characteristic enablement step after executing the load sharing step, and executes a droop characteristic modification step of modifying the droop characteristic.

4. The startup method of microgrid according to claim 2 , wherein the control mode changing step to droop mode selects an order of the droop characteristic enablement step and the load sharing step based on fluctuation amount of frequency or voltage allowed in the microgrid.

5. The startup method of microgrid according to claim 1 , wherein the control mode changing step is a control mode changing step to a VSG mode of changing the CVCF mode of the master to the VSG mode of the master and changing the grid interconnection mode of the slave to the VSG mode of the slave.

6. The startup method of microgrid according to claim 1 , wherein the command value from outside the microgrid and an active power output of the slave is matched in a certain range before the slave is started up.

7. The startup method of microgrid according to claim 1 , wherein voltage produced by the slave and grid voltage are matched.

8. A startup program of microgrid executed by a computer, the microgrid configured by a plurality of inverter power supplies independently sharing a load and divided into a master that starts up first and a slave that starts up secondly and later, the startup program comprising:
a master initial startup step of initially starting up the master in a CVCF mode;
a slave initial startup step of initially starting up the slave in a grid interconnection mode; and
a control mode changing step of the master and the slave changing control modes thereof when output fluctuation of the master and the slave becomes a predetermined threshold or less or when the master and the slave or other inverter power supplies become a predetermined operation state while output voltage of said master and said slave becomes a predetermined threshold or less.

9. The startup method of microgrid according to claim 3 , wherein the control mode changing step to droop mode selects an order of the droop characteristic enablement step and the load sharing step based on fluctuation amount of frequency or voltage allowed in the microgrid.

10. The startup method of microgrid according to claim 6 , wherein voltage produced by the slave and grid voltage are matched.

Assignees

• Toshiba Kk
• Toshiba Energy Systems & Solutions Corp

Inventors

• Sakauchi Yoko
• Akiyama Yukina
• Kudo Yuki
• Kawachi Shunsuke
• Toba Koji

Classifications

• H02J2101/24

  Photovoltaics · CPC title

• H02J3/00142 Primary

  Oscillations concerning frequency · CPC title

• H02M7/48

  using discharge tubes with control electrode or semiconductor devices with control electrode · CPC title

• H02J3/46

  Controlling the sharing of generated power between the generators, sources or networks · CPC title

• H02J3/32 Primary

  using batteries or super capacitors with converting means · CPC title