The present application relates to a system capable of supplying power without interruption even when an abnormality occurs in some components of a power system.
background
[2]
A microgrid or the like is used as a system for supplying power. The microgrid is composed of various power generation facilities, energy storage devices, etc., centering on an AC grid such as a bus system, and may be implemented by disposing various types of power converters in areas requiring power control.
[3]
(Patent Document) Republic of Korea Patent Registration No. 10-1277185
DETAILED DESCRIPTION OF THE INVENTION
technical challenge
[4]
According to an embodiment of the present invention, there is provided a power supply microgrid system capable of supplying power without interruption even if an abnormality occurs in some components of the power system.
means of solving the problem
[5]
A power supply microgrid system according to an embodiment of the present invention is a first node to which AC power is applied from a bus system, a first generator for applying DC power to the second node, and a third node connected to the third node to receive AC power. A first load, a second load connected to the second node to receive DC power, a third load connected to a fourth node to receive AC power, and a third load that converts the DC power of the second node into AC power and outputs it A first converter, a second converter that converts DC power of the second node into AC power and outputs it, and the first node, the third node, and the fourth node according to states of the first converter and the second converter , a switch unit for adjusting a connection relationship between the first converter, and the second converter.
[6]
The switch unit of the power supply microgrid system according to an embodiment of the present invention connects the first node and the fourth node when AC power is applied to the first node from the bus system and the first converter is normal. and connect the first node and the third node. In this case, the switch unit may adjust the connection relationship so that the AC power output from the first converter is applied to the third node.
[7]
When the switch unit of the power supply microgrid system according to an embodiment of the present invention does not apply AC power from the bus system to the first node, and the first converter and the second converter are normal, in the first converter The connection relationship may be adjusted so that AC power output from the third node is applied to the third node and AC power output from the second converter is applied to the fourth node.
[8]
When the switch unit of the power supply microgrid system according to an embodiment of the present invention does not apply AC power from the bus system to the first node, the first converter does not operate, and the second converter is normal, the The AC power output from the second converter may be applied to the fourth node, and the connection relationship may be adjusted such that the fourth node and the third node are connected.
[9]
The power supply microgrid system according to an embodiment of the present invention may further include a second generator for applying AC power to the fifth node.
[10]
The switch unit of the power supply microgrid system according to an embodiment of the present invention may connect the fifth node and the third node when AC power is not applied from the bus system to the first node. In this case, when the second converter does not operate, the switch unit may connect the fifth node and the fourth node.
[11]
In the power supply system according to another embodiment of the present invention, a first node to which AC power is applied from a bus system, DC power is applied from a first generator, and a second node connected to a first load, AC power is applied, A third node connected to a second load, to which AC power is applied, a fourth node connected to a third load, a first converter for converting DC power of the second node into AC power and outputting it, and the second node A second converter that converts DC power into AC power and outputs it, a fifth node to which AC power is applied from the second generator, a first switch selectively connecting the first node or the fifth node with a sixth node, the A second switch connected between a first node and a seventh node, a third switch connected between the sixth node and the seventh node, a fourth switch connected between the sixth node and the third node, the third node and a fifth switch connected between the first converter, a sixth switch connected between the second converter and the fourth node, and a seventh switch connected between the seventh node and the fourth node.
[12]
The first switch of the power supply system according to another embodiment of the present invention is an automatic changeover switch, the second switch, the fifth switch, and the sixth switch are switches having mechanical contacts, the third switch and The seventh switch may be a switch having an electronic contact point.
[13]
The power supply system according to another embodiment of the present invention further includes an eighth switch connected in parallel with the fourth switch, wherein the fourth switch is a switch having an electronic contact, and the eighth switch has a mechanical contact It may be a switch.
[14]
The power supply system according to another embodiment of the present invention may further include a ninth switch connected between the bus system and the first node.
[15]
In the power supply system according to another embodiment of the present invention, when AC power is applied from the bus system to the first node, and the first converter and the second converter are normal, the first switch is connected to the first node The sixth node may be connected, and the second switch, the fourth switch, the fifth switch, and the seventh switch may be turned on, and the third switch and the sixth switch may be turned off.
[16]
In the power supply system according to another embodiment of the present invention, when AC power is not applied from the bus system to the first node, and the first converter and the second converter are normal, the first switch is the fifth node and the sixth node, the fourth switch, the fifth switch, and the sixth switch may be turned on, and the second switch, the third switch, and the seventh switch may be turned off.
[17]
In the power supply system according to another embodiment of the present invention, when AC power is not applied from the bus system to the first node, the first converter is normal, and the second converter does not operate, the first switch connects the fifth node and the sixth node, the third switch, the fourth switch, the fifth switch, and the seventh switch are turned on, and the second switch and the sixth switch are turned off can
[18]
In the power supply system according to another embodiment of the present invention, when AC power is not applied from the bus system to the first node, the second converter is normal, and the first converter does not operate, the first switch connects the fifth node and the sixth node, the third switch, the fourth switch, the sixth switch, and the seventh switch are turned on, and the second switch and the fifth switch are turned off can
[19]
In the power supply system according to another embodiment of the present invention, when AC power is not applied to the first node from the bus system, and the first converter and the second converter do not operate, the first switch is The fifth node and the sixth node may be connected, the third switch, the fourth switch, and the seventh switch may be turned on, and the second switch, the fifth switch, and the sixth switch may be turned off.
[20]
In the power supply system according to another embodiment of the present invention, the first converter is a bidirectional converter that further performs a function of converting AC power of a third node to DC power and outputting it, and the second converter may be an inverter.
Effects of the Invention
[21]
Therefore, according to the power supply microgrid system according to the embodiment of the present invention, even if an abnormality occurs in the power system or an abnormality occurs in some components constituting the system, power can be supplied without interruption. In addition, the power supply microgrid system of the present invention enables seamless power supply without duplicating power systems or converters, thereby reducing investment costs.
Brief description of the drawing
[22]
1 is a diagram schematically showing a power supply microgrid system according to an embodiment of the present invention.
[23]
FIG. 2 is a diagram for explaining an energy flow when no abnormality occurs in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[24]
FIG. 3 is a diagram for explaining an energy flow when an error occurs in a bus system in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[25]
FIG. 4 is a view for explaining an energy flow when an error occurs in a bus system and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[26]
FIG. 5 is a diagram for explaining an energy flow when an error occurs in a bus system and a converter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[27]
FIG. 6 is a view for explaining an energy flow when an abnormality occurs in a bus system, a converter, and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[28]
7 is a view for explaining an energy flow when an abnormality occurs in a bus system, an emergency generator, a converter, and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
Best mode for carrying out the invention
[29]
Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings. However, the embodiment of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below. In addition, the embodiment of the present invention can further improve the present invention to those of ordinary skill in the art. It is provided for complete explanation.
[30]
[31]
1 is a diagram schematically showing a power supply microgrid system according to an embodiment of the present invention. The power supply microgrid system according to an embodiment of the present invention is a busbar system 10 , a first generator 20 , a second generator 30 , an energy storage device 40 , a first load 51 , and a second The load 52 , the third load 53 , and a switch unit including a plurality of switches 60 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 81 , 82 , 83 and 100 , and a converter 91 . ), and an inverter 92 .
[32]
[33]
The bus system 10 may supply alternating current (AC) power to the first node N1 . The bus system 10 may be a system that transmits power from an external power plant to the first node N1 .
[34]
The first generator 20 may supply direct current (DC) power to the second node N2 . The first generator 20 may be a generator of various types, such as a solar generator. When the first generator 20 is a photovoltaic generator, the first generator 20 includes a photovoltaic power generation facility 21 such as a solar cell that generates electric power by incident sunlight, and the photovoltaic power generation facility 21 is generated. It may include a converter 22 that converts one electric power into DC power having a constant voltage or a constant current. In this case, the converter 22 may be a DC/DC converter.
[35]
The second generator 30 may supply AC power to the fifth node N5 . The second generator 30 may be a diesel engine generator, and may function as an emergency generator when power is not supplied from the bus system 10 .
[36]
The energy storage device 40 may store energy using the power supplied to the second node N2 , or may supply the stored energy to the second node N2 . The energy storage device 40 may be composed of a rechargeable battery or the like.
[37]
The first load 51 is connected to the third node N3 and may receive AC power through the third node N3 . The first load 51 may have an incomplete uninterruptible characteristic. That is, in some cases, AC power may not be supplied to the first load 51 . The first load 51 is AC power converted from AC power supplied from the bus system 10 to the first node N1, and DC power supplied to the second node N2 by the second generator 20, At least one of AC power converted from DC power supplied to the second node N2 by the energy storage device 40 and AC power supplied to the fifth node N5 by the second generator 30 It can be supplied through the switch unit.
[38]
The second load 52 is connected to the second node N2 and may receive DC power through the second node N2 . The second load 52 may have a completely uninterruptible characteristic. That is, the second load 52 may be implemented such that DC power is always supplied to the second load 52 in any situation except for blocking the overcurrent. The second load 52 switches at least one of the DC power supplied to the second node N2 by the second generator 20 and the DC power supplied to the second node N2 by the energy storage device 40 . It can be supplied through wealth. In some cases, the second load 52 is supplied to the fifth node N5 by the DC power converted from the AC power supplied from the bus system 10 to the first node N1 and the second generator 30 . At least one of the converted AC power may be supplied through the switch unit.
[39]
The third load 53 is connected to the fourth node N4 and may receive AC power through the fourth node N4 . The third load 53 may have a more complete uninterruptible characteristic than the first load 51 . That is, except in exceptional cases, AC power may be supplied to the third load 53 . The third load 53 is AC power supplied from the bus system 10 to the first node N1, and the DC power supplied to the second node N2 by the second generator 20 is converted to AC power, At least one of AC power converted from DC power supplied to the second node N2 by the energy storage device 40 and AC power supplied to the fifth node N5 by the second generator 30 It can be supplied through the switch unit.
[40]
The converter 91 may convert the DC power of the second node N2 into AC power and transmit it to the third node N3 . AC power output from the converter 91 is AC power supplied from the bus system 10 and applied to the third node N3 or AC generated by the second generator 30 and applied to the third node N3 It can be adjusted to have the same phase as the power. Alternatively, the converter 91 may convert the AC power of the third node N2 into DC power and transmit it to the second node N2 . That is, the converter 91 may be a bidirectional converter.
[41]
The inverter 92 may convert the DC power of the second node N2 into AC power and transmit it to the fourth node N4 . The inverter 92 may be a constant voltage constant frequency (CVCF) inverter.
[42]
The switch unit may form different power transmission paths according to the states of the bus system 10 , the second generator 30 , the converter 91 , and the inverter 92 .
[43]
The switch unit includes a switch 60 connecting the first node N1 or the fifth node N5 to the sixth node N6, and a switch 73 connected between the sixth node N6 and the third node N3. , the switch 81 connected between the sixth node N6 and the third node N3, the switch 83 connected between the sixth node N6 and the seventh node N7, and the first node N1 and The switch 72 connected between the seventh node N7, the switch 82 connected between the seventh node N1 and the fourth node N4, and the switch connected between the third node N3 and the converter 91 74 , and a switch 75 connected between the inverter 92 and the fourth node N4 .
[44]
The switch unit includes at least one switch 71 and 100 connected between the bus system 10 and the first node N1, a switch 76 connected between the second node N2 and the energy storage device 40, and a second A switch 77 connected between the second node N2 and the second load 52 may be further included. The switches 76 and 77 may remain in an on state unless there is a special case (eg, when overcurrent blocking is required). In addition, the switches 71 and 100 may maintain an ON state unless an abnormality occurs in the bus system 10 .
[45]
The switch 60 may be an Automatic Transfer Switch (ATS), and the switches 71 , 72 , 73 , 74 , 75 , 76 , and 77 are physical such as a Molded Case Circuit Breaker (MCCB). It may be a switch having a contact point, and the switches 81 , 82 , 83 may be a switch having an electronic contact point, such as a static transfer switch (STS). The switch 100 may be an air circuit breaker (ACB).
[46]
An operation of each of the switches of the switch unit will be described with reference to FIGS. 2 to 7 .
[47]
In addition, the power supply microgrid system of the present invention may additionally include an inductor connected in series with the switch 82 .
[48]
In addition, although not shown, the power supply microgrid system according to an embodiment of the present invention grasps the state of the bus system 10, the second generator 30, the converter 91, and the inverter 92, and switches It may further include a control unit for controlling the negative switches.
[49]
[50]
FIG. 2 is a diagram for explaining an energy flow when no abnormality occurs in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[51]
When all of the bus system 10 , the converter 91 , and the inverter 92 operate normally, the second generator 30 may not operate.
[52]
Also, in this case, the AC power supplied from the bus system 10 is applied to the first node N1 . For this, the switches 100 and 71 may be turned on.
[53]
Also, AC power applied to the first node N1 may be supplied to the third load 53 . To this end, switches 72 and 82 may be turned on and switch 75 may be turned off. Also, the inverter 92 may not operate.
[54]
At least one of AC power applied to the first node N1 and DC power converted by the converter 91 may be supplied to the first load 51 . To this end, the switch 60 connects the first node N1 and the sixth node N6, at least one of the switches 73 and 81 and the switch 74 are turned on, and the switch 74 is turned on. can Also, the switch 83 may be turned off.
[55]
Also, in this case, the DC power applied to the second node N2 may be supplied to the second load 52 . For this, the switch 77 may be turned on. Also, the converter 91 may convert the AC power applied to the third node N3 into DC power and output the converted AC power to the second node N2 .
[56]
[57]
FIG. 3 is a diagram for explaining an energy flow when an error occurs in a bus system in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[58]
When AC power is not applied to the first node N1 due to an abnormality in the bus system 10 , the second generator 30 may operate.
[59]
In addition, when an abnormality occurs in the bus system 10 , and the second generator 30 , the converter 91 , and the inverter 92 operate, the third load 53 is the AC output from the inverter 92 . receive power To this end, when an abnormality occurs in the bus system 10 , the inverter 92 may be operated immediately, and the switch 75 may be turned on. Therefore, even if an abnormality occurs in the busbar system 10 , it is short from the time when the abnormality occurs in the busbar system 10 .AC power may be supplied to the third load 53 within a time period (eg, 4 msec). That is, the power failure time of the third load 53 may be very short. In this case, the switches 72, 82, 83 may be turned off.
[60]
Also, in this case, the first load 51 may receive AC power generated by the second generator 30 . To this end, the switch 60 may connect the fifth node N5 and the sixth node N6, and at least one of the switches 73 and 81 may be turned on. The switch 83 may be turned off. The first load 51 may receive AC power output from the converter 91 . To this end, the converter 91 may convert the DC power of the second node N2 to AC power and output it, and the switch 74 may be turned on. Accordingly, AC power may be supplied to the first load 51 within a predetermined time (eg, 100 msec) from the time when an abnormality occurs in the bus system 10 . Also, in this case, the AC power output from the converter 91 may be adjusted to have the same phase as the AC power generated by the second generator 30 and applied to the third node N3 . For this reason, the second generator 30 and the converter 91 are switched to the parallel operation mode, and thus power can be more stably supplied to the first load 51 .
[61]
Also, in this case, the DC power applied to the second node N2 may be supplied to the second load 52 . For this, the switch 77 may be turned on. Also, the converter 91 may convert the AC power applied to the third node N3 into DC power and output the converted AC power to the second node N2 .
[62]
[63]
FIG. 4 is a view for explaining an energy flow when an error occurs in a bus system and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[64]
When AC power is not applied to the first node N1 due to an abnormality in the bus system 10 , the second generator 30 may operate. Also, the switch 60 may connect the fifth node N5 to the sixth node N6 .
[65]
In addition, when an abnormality occurs in the bus system 10 and the inverter 92 , and the second generator 30 and the converter 91 operate normally, the third load 53 is generated by the second generator 30 . AC power can be supplied. For this, switches 83 and 82 may be turned on. The switch 75 may be off. Also, the third load 53 may receive AC power output from the converter 91 . To this end, the converter 91 may convert the DC power of the second node N2 to AC power and output it, and the switch 74 may be turned on.
[66]
Also, in this case, the first load 51 may receive AC power generated by the second generator 30 . To this end, the switch 60 may connect the fifth node N5 and the sixth node N6, and at least one of the switches 73 and 81 may be turned on. The switch 83 may be turned off. The first load 51 may receive AC power output from the converter 91 . To this end, the converter 91 may convert the DC power of the second node N2 to AC power and output it, and the switch 74 may be turned on. Accordingly, AC power may be supplied to the first load 51 within a predetermined time (eg, 100 msec) from the time when an abnormality occurs in the bus system 10 .
[67]
Also, in this case, the DC power applied to the second node N2 may be supplied to the second load 52 . For this, the switch 77 may be turned on. Also, the converter 91 may convert the AC power applied to the third node N3 into DC power and output the converted AC power to the second node N2 .
[68]
That is, in the case of FIG. 4 , the second generator 30 and the converter 91 may operate in a parallel operation mode. Accordingly, power may be more stably supplied to the first load 51 and the third load 53 .
[69]
[70]
FIG. 5 is a diagram for explaining an energy flow when an error occurs in a bus system and a converter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[71]
When AC power is not applied to the first node N1 due to an abnormality in the bus system 10 , the second generator 30 may operate. Also, the switch 60 may connect the fifth node N5 to the sixth node N6 .
[72]
When an abnormality occurs in the bus system 10 and the converter 91 , and the second generator 30 and the inverter 92 operate, the third load 53 supplies the AC power output from the inverter 92 . receive To this end, the switch 75 can be turned on and the switch 72 can be turned off.
[73]
Also, in this case, the first load 51 may receive AC power generated by the second generator 30 . To this end, the switch 60 may connect the fifth node N5 and the sixth node N6, and at least one of the switches 73 and 81 may be turned on. The switch 74 may be off. The first load 51 may receive AC power output from the inverter 92 . For this, switches 75, 82, 83 may be turned on. Also, in this case, the AC power output from the inverter 92 may be adjusted to have the same phase as the AC power generated by the second generator 30 and applied to the third node N3 . That is, since the second generator 30 and the inverter 92 operate in the parallel operation mode, power may be more stably supplied to the first load 51 .
[74]
Also, in this case, the DC power applied to the second node N2 may be supplied to the second load 52 . For this, the switch 77 may be turned on.
[75]
[76]
FIG. 6 is a view for explaining an energy flow when an abnormality occurs in a bus system, a converter, and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[77]
When AC power is not applied to the first node N1 due to an abnormality in the bus system 10 , the second generator 30 may operate. Also, the switch 60 may connect the fifth node N5 to the sixth node N6 .
[78]
In addition, when an abnormality occurs in the bus system 10 , the converter 91 , and the inverter 92 , and the second generator 30 operates normally, the third load 53 is the second generator 30 The generated AC power is supplied. For this, switches 83 and 82 may be turned on. The switch 75 may be off.
[79]
Also, in this case, the first load 51 may receive AC power generated by the second generator 30 . To this end, the switch 60 may connect the fifth node N5 and the sixth node N6, and at least one of the switches 73 and 81 may be turned on. The switch 74 may be off.
[80]
Also, in this case, the DC power applied to the second node N2 may be supplied to the second load 52 . For this, the switch 77 may be turned on.
[81]
[82]
7 is a view for explaining an energy flow when an abnormality occurs in a bus system, an emergency generator, a converter, and an inverter in the power supply microgrid system according to an embodiment of the present invention shown in FIG. 1 .
[83]
When an abnormality occurs in the bus system 10 , the emergency generator 30 , the converter 91 , and the inverter 92 , the DC power applied to the second node N2 may be supplied to the second load 52 . have. For this, the switch 77 may be turned on.
[84]
Also, in this case, power may not be supplied to the first load 51 and the third load 53 .
[85]
[86]
Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and variations are possible within the scope without departing from the technical spirit of the present invention described in the claims. It will be apparent to those of ordinary skill in the art.
Claims
[Claim 1]
a first node to which AC power is applied from the bus system; a first generator for applying DC power to the second node; a first load connected to the third node to receive AC power; a second load connected to the second node to receive DC power; a third load connected to the fourth node to receive AC power; a first converter for converting the DC power of the second node into AC power and outputting it; a second converter for converting the DC power of the second node into AC power and outputting it; and a switch unit configured to adjust a connection relationship between the first node, the third node, the fourth node, the first converter, and the second converter according to the states of the first converter and the second converter. Power supply microgrid system.
[Claim 2]
The method of claim 1, wherein the switch unit connects the first node and the fourth node when AC power is applied from the bus system to the first node and the first converter is normal, and the first node and A power supply microgrid system connecting the third node.
[Claim 3]
The power supply microgrid system according to claim 2, wherein the switch unit adjusts the connection relationship so that the AC power output from the first converter is applied to the third node.
[Claim 4]
According to claim 1, wherein the switch unit AC power is not applied to the first node from the bus system, when the first converter and the second converter are normal, the AC power output from the first converter is A power supply microgrid system that is applied to three nodes and adjusts the connection relationship so that AC power output from the second converter is applied to the fourth node.
[Claim 5]
The AC output from the second converter of claim 1 , wherein the switch unit does not apply AC power from the bus system to the first node, the first converter does not operate, and the second converter is normal. Power is applied to the fourth node, and the power supply microgrid system adjusts the connection relationship so that the fourth node and the third node are connected.
[Claim 6 ]
The power supply microgrid system according to claim 1, wherein the power supply microgrid system further comprises a second generator for applying alternating current power to the fifth node.
[Claim 7]
The power supply microgrid system of claim 6, wherein the switch unit connects the fifth node and the third node when AC power is not applied from the bus system to the first node.
[Claim 8]
The power supply microgrid system of claim 7 , wherein the switch unit connects the fifth node and the fourth node when the second converter does not operate.
[Claim 9]
a first node to which AC power is applied from the bus system; a second node to which DC power is applied from the first generator and connected to the first load; a third node to which AC power is applied and connected to a second load; a fourth node to which AC power is applied and connected to a third load; a first converter for converting the DC power of the second node into AC power and outputting it; a second converter for converting the DC power of the second node into AC power and outputting it; a fifth node to which AC power is applied from the second generator; a first switch selectively connecting the first node or the fifth node to a sixth node; a second switch connected between the first node and the seventh node; a third switch connected between the sixth node and the seventh node; a fourth switch connected between the sixth node and the third node; a fifth switch connected between the third node and the first converter; a sixth switch connected between the second converter and the fourth node; and a seventh switch connected between the seventh node and the fourth node.
[Claim 10]
10. The method of claim 9, wherein the first switch is an automatic changeover switch, the second switch, the fifth switch, and the sixth switch are switches having mechanical contacts, and the third switch and the seventh switch are electronic A power supply microgrid system that is a switch with contacts.
[Claim 11]
10. The method of claim 9, wherein the power supply microgrid system further comprises an eighth switch connected in parallel with the fourth switch, the fourth switch is a switch having an electronic contact, the eighth switch is a mechanical contact A power supply microgrid system that is a switch.
[Claim 12]
The power supply microgrid system according to claim 9, wherein the power supply microgrid system further comprises a ninth switch connected between the bus grid and the first node.
[Claim 13]
The method of claim 9, wherein when AC power is applied from the bus system to the first node and the first converter and the second converter are normal, the first switch connects the first node and the sixth node. and the second switch, the fourth switch, the fifth switch, and the seventh switch are on, and the third switch and the sixth switch are off.
[Claim 14]
10. The method of claim 9, When AC power is not applied from the bus system to the first node and the first converter and the second converter are normal, the first switch connects the fifth node and the sixth node. and the fourth switch, the fifth switch, and the sixth switch are turned on, and the second switch, the third switch, and the seventh switch are turned off.
[Claim 15]
The method of claim 9, wherein when AC power is not applied from the bus system to the first node, the first converter is normal, and the second converter does not operate, the first switch is connected to the fifth node. A power supply microgrid system that connects the sixth node, wherein the third switch, the fourth switch, the fifth switch, and the seventh switch are turned on, and the second switch and the sixth switch are turned off.
[Claim 16]
The method of claim 9, wherein when AC power is not applied from the bus system to the first node, the second converter is normal, and the first converter does not operate, the first switch is connected to the fifth node. A power supply microgrid system that connects the sixth node, wherein the third switch, the fourth switch, the sixth switch, and the seventh switch are turned on, and the second switch and the fifth switch are turned off.
[Claim 17]
The method of claim 9, wherein when AC power is not applied from the bus system to the first node and the first converter and the second converter do not operate, the first switch is configured to operate between the fifth node and the sixth node. A power supply microgrid system that connects nodes, wherein the third switch, the fourth switch, and the seventh switch are turned on, and the second switch, the fifth switch, and the sixth switch are turned off.
[Claim 18]
The power supply microgrid system according to claim 9, wherein the first converter is a bidirectional converter that further converts the AC power of the third node into DC power and outputs it, and the second converter is an inverter.