1. A method (20) for automatically self-configuring a network device being added to a network comprising:
attempting (21) to access a predetermined service from the network, which predetermined service is also capable of being performed by the network device;
upon (24) successfully accessing the predetermined service by the network device, disabling the predetermined service within the network device; and
upon (23) unsuccessfully accessing the predetermined service by the network device, activating the predetermined service within the network device.
2. The method (20) according to claim 1, wherein the predetermined service includes a network address translation service.
3. The method (20) according to claim 1, wherein the predetermined service includes a dynamic host configuration protocol server.
4. The method (20) according to claim 1, wherein the predetermined service includes DNS service.
5. The method (20) according to claim 1, further comprising:
acquiring (31) an Internet Protocol address from the network;
determining (32) if the Internet Protocol address assigned by the network is a private Internet Protocol address.
6. The method (20) according to claim 5, further comprising:
upon (34) determining that the assigned Internet Protocol address is a private Internet Protocol address, self-configuring the network device to use a local area network port to access the Internet and the network.
7. The method (20) according to claim 5, further comprising:
upon (33) determining that the assigned Internet Protocol address is not a private Internet Protocol address, self-configuring the network device to use a wide area network port to access the Internet and a local area network port to access the network.
8. A method (30) for automatically self-configuring a network device being added to a network comprising:
acquiring (31) an Internet Protocol address from the network;
determining (32) if the Internet Protocol address assigned by the network is a private Internet Protocol address; and
upon (34) determining that the assigned Internet Protocol address is a private Internet Protocol address, self-configuring the network device to use a local area network port to access the Internet and the network.
9. The method (30) according to claim 8, further comprising:
upon (33) determining that the assigned Internet Protocol address is not a private Internet Protocol address, self-configuring the network device to use a wide area network port to access the Internet and a local area network port to access the network.
10. The method (30) according to claim 8, further comprising:
attempting (21) to access a predetermined service from the network, which predetermined service is also capable of being performed by the network device;
upon successfully (24) accessing the predetermined service by the network device, disabling the predetermined service within the network device; and
upon (23) unsuccessfully accessing the predetermined service by the network device, activating the predetermined service within the network device.
11. The method (30) according to claim 8, further comprising:
attempting (21) to access one or more predetermined services from the network, each of which one or more predetermined services is also capable of being performed by the network device;
disabling (24) within the network device each of the one or more predetermined services that were successfully accessed by the network device; and
enabling (23) within the network device each of the one or more predetermined services that were unsuccessfully accessed by the network device.
12. The method (30) according to claim 10, wherein the predetermined service includes a network address translation service.
13. The method (30) according to claim 10, wherein the predetermined service includes a dynamic host configuration protocol server.
14. The method (30) according to claim 10, wherein the predetermined service includes DNS service.
15. A method (30) for automatically self-configuring a network device being added to a network comprising:
acquiring (31) an Internet Protocol address from the network; and
self-configuring (33) the network device to act as a gateway to the Internet for the network based on a format of the Internet Protocol address.
16. The method (30) according to claim 15, wherein the format of the Internet Protocol address includes an address type.
17. The method (30) according to claim 15, wherein the address type includes a public Internet Protocol address.
18. The method (30) according to claim 15, wherein the address type includes a private Internet Protocol address.
19. The method (30) according to claim 15, wherein the address type includes a format that matches 192.168.x.x or 10.x.x.x wherein the numbers constitute octets and the x constitutes any octet.
20. A method (40) for self-configuring a network device comprising:
sending (41) a DHCP discover message to the network upon coupling the network device to a network;
upon (43) receiving no response to the DHCP discover message, enabling DHCP service within the network device;
upon (44) receiving a response to the DHCP discover message, sending a DHCP request for an IP address;
upon (45) receiving a response to the DHCP request message, examining the received IP address to determine if the received IP address is a private IP address or not; and
upon (47) determining that the received IP address is a private IP address, then using a single LAN port to access the network and the Internet; and
upon (46) determining that the received UP address is not a private IP address, then using a LAN port to access the network and a WAN port to access the Internet.
21. An apparatus (13, 17) for coupling to a network comprising:
a local area network port (5);
a wide area network port (6);
a processor (4) to send data to and from the local area network port (5) and the wide area network port (6), said processor (4):
sending (41) a DHCP discover message to the network upon coupling the local area network port (5) to a network;
upon (43) receiving no response to the DHCP discover message, enabling DHCP service;
upon (44) receiving a response to the DHCP discover message, sending a DHCP request for an IP address;
upon (45) receiving a response to the DHCP request message, examining the received IP address to determine if the received IP address is a private IP address or not; and
upon (47) determining that the received IP address is a private IP address, then using the local area network port (5) to access the network and the Internet; and
upon (46) determining that the received UP address is not a private IP address, then using the local area network port (5) to access the network and the wide area network port (6) to access the Internet.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A parallel inverter device, comprising a plurality of inverters connected in parallel that supply alternating current voltage to a single load and a transmission means, wherein
each of the plurality of inverters includes
a power converter that converts direct current to alternating current and supplies alternating current voltage to the single load, and
a power converter control unit;
one of the inverters is a master inverter, the control unit thereof computing a voltage command value for the power converter in the master inverter, and an other of the inverters is a slave inverter, the power converter of the slave inverter being driven in accordance with said voltage command value;
the transmission means transmits the voltage command value computed by the control unit of the master inverter to the slave inverter; and
the control unit of the master inverter includes a delay device that delays the voltage command value by a transmission time needed for transmitting a computed voltage command value to the slave inverter, and provides the voltage command value delayed by the delay device to the power converter of the master inverter.
2. The parallel inverter device according to claim 1, wherein the slave inverter includes a synchronization device that synchronizes switching timing of the power converter of the slave inverter with switching timing of the power converter of the master inverter.
3. The parallel inverter device according to claim 1, wherein the master inverter transmits the voltage command value in synchronization with the switching timing of the power converter of the master inverter in a fixed cycle, and the control unit of the master inverter controls a time from a start of transmission to a finish of transmission of the voltage command value by the master inverter and a time from a start of reception to a completion of reception of the voltage command value by the slave inverter to be equal.
4. The parallel inverter device according to claim 1, wherein the delay device adjusts the delay time so that the voltage command value for the master inverter and the voltage command value for the slave inverter are equal.
5. The parallel inverter device according to claim 1, wherein the power converter further comprises a semiconductor switching element.
6. A parallel inverter device, comprising three or more inverters connected in parallel that supply alternating current voltage to a single load, and a transmission means, wherein
each of the inverters includes
a power converter that carries out a direct current to alternating current conversion, and supplies alternating current voltage to the load,
a power converter control unit having a delay device;
one of the inverters is a master inverter, the control unit of the master inverter computing a voltage command value for the power converter of the master inverter, the other inverters are slave inverters, and the power converters in the slave inverters are driven in accordance with the voltage command value;
the transmission means transmits a voltage command value computed by the control unit of the master inverter to the slave inverters;
the delay unit of the master inverter delays the voltage command value by a transmission time for transmitting the computed voltage command value to one of the slave inverters that requires a longest transmission time, and provides the voltage command value delayed by the delay device to the power converter of the master inverter, and
the delay device of each of the slave inverters delays the voltage command value transmitted from the master inverter or another slave inverter so as to provide a voltage command value synchronous with the voltage command value delayed by the delay device of the master inverter to the power converter of the slave inverter.
7. The parallel inverter device according to claim 6, wherein each said slave inverter includes a synchronization device that synchronizes switching timing of the power converter of said slave inverter with switching timing of the power converter of the master inverter.
8. The parallel inverter device according to claim 6, wherein the master inverter
transmits the voltage command value in synchronization with the switching timing of the power converter of the master inverter in a fixed cycle, and
controls so that the time from a start of transmission to a finish of transmission of the voltage command value by the master inverter and a time from a start of reception to a completion of reception of the voltage command value by each slave inverter are identical.
9. The parallel inverter device according to claim 6, wherein the delay device adjusts the delay time so that the voltage command value for the master inverter and the voltage command value for each of the slave inverters are equal to each other.
10. The parallel inverter device according to claim 6, wherein the power converter further comprises a semiconductor switching element.
11. A method of controlling a parallel inverter device that includes a plurality of parallel-connected inverters, including a master converter and at least one slave converter, that supply alternating current voltage to a single load, the method comprising:
converting direct current to alternating current by a switching action of a power converter in each of the inverters,
supplying the alternating current voltage to the single load,
computing a voltage command value for the power converter the master inverter,
driving the power converter in the slave inverter in accordance with the voltage command value,
transmitting the voltage command value to the slave inverter,
delaying the voltage command value by a transmission time for transmitting a computed voltage command value to the slave inverter, and
providing the delayed voltage command value to the power converter of the master inverter.
12. The method according to claim 11, further comprising synchronizing switching timing of the power converter of the slave inverter with switching timing of the power converter of the master inverter.
13. The method according to claim 11, further comprising
transmitting the voltage command value in synchronization with the switching timing of the power converter of the master inverter in a fixed cycle, and
controlling a time from a start of transmission to a finish of transmission of the voltage command value from the master inverter and a time from a start of reception to a completion of reception of a voltage command value by the slave inverter to be equal to each other.
14. The method according to claim 11, further comprising adjusting the delay time so that the voltage command value for the master inverter and the voltage command value for the slave inverter are equal to each other.