JP2014128120A - Distributed power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a distributed power supply system capable of preventing generation of an inverse load flow to a power system.SOLUTION: In the distributed power supply system, a power generation device 20 comprises a power generation control section 22 controlling generated power to supply the same power to a first voltage line 2a and a second voltage line 2b in such a manner that the total of power from the side of a first connection point P1 to the side of a second connection point P2 through the first voltage line 2a and the second voltage line 2b becomes minimum and does not become negative. An auxiliary power supply device 10 comprises an operation control section 11 individually regulating output power from a power storage section 12 to the first voltage line 2a and the second voltage line 2b to a value equal to or greater than zero in such a manner that the total of power from the side of a power system 1 to the first connection point P1 through the first voltage line 2a and the second voltage line 2b does not become negative in the case where positive and negative codes of power from the side of the first connection point P1 to the side of the second connection point P2 through the first voltage line 2a and power from the side of the first connection point P1 to the second connection point P2 through the second voltage line 2b are different from each other.

Description

  The present invention is connected to a single phase three-wire AC line having a first voltage line, a second voltage line, and a neutral line connected to an electric power system, and connected to the AC line at a first connection point. An auxiliary power supply device, a power generation device connected to the AC line at the second connection location, and a power consuming device connected to the second connection location of the AC line, as seen from the connection location of the power system to the AC line. The present invention relates to a distributed power supply system in which a first connection location and a second connection location are provided in the arrangement order toward the downstream side.

  In Patent Document 1, an auxiliary power supply device having a power storage unit, a power generation device, and a power consumption device are connected to an AC line connected to a commercial power system, and the power consumption device is connected to the power system, the auxiliary power supply device, and the power generation device. A distributed power supply system that is configured to be capable of supplying power to is described. In particular, in Patent Document 1, switching between output operation of the power storage unit included in the auxiliary power supply device or power generation operation of the power generation device is performed according to the output capacity of the power storage unit included in the auxiliary power supply device. It describes that power is supplied to the power consuming device.

JP 2000-333386 A

  Although not described in Patent Document 1, a single phase composed of two voltage lines and one neutral line as an AC line to which the auxiliary power supply device, the power generation device, and the power consumption device as described above are connected. A three-wire AC line is used. FIG. 4 is a diagram schematically illustrating a distributed power supply system in which an auxiliary power supply device, a power generation device, and a power consumption device are connected to a single-phase three-wire AC line. In addition, although illustration is abbreviate | omitted, when connecting a single-phase three-wire type AC line which has a 1st voltage line, a 2nd voltage line, and a neutral line, an auxiliary power supply device, and a power generator, between them Is provided with a power converter such as an inverter or a converter. The power converter adjusts the output power from the auxiliary power supply device to the AC line and the power supplied from the power generation device to the AC line (generated power).

  When connecting an auxiliary power supply device or a power generation device to a single-phase three-wire AC line via a power conversion unit, specifically, the power conversion unit is composed of a single power conversion circuit unit and the single power A configuration in which the conversion circuit unit is commonly connected to the first voltage line and the second voltage line, or a power conversion unit is configured by two power conversion circuit units, one of which is connected to the first voltage line and the other is the first voltage line. A configuration connected to two voltage lines is conceivable.

In the former case, the power conversion unit (single power conversion circuit unit) can adjust the power exchanged between the first voltage line and the second voltage line in common, but the first voltage line and The power exchanged with the second voltage line cannot be adjusted individually, that is, for each phase. In the latter case, the power conversion unit (two power conversion circuit units) uses each power conversion circuit unit to separately transmit power exchanged between the first voltage line and the second voltage line, that is, one phase. Can be adjusted every time.
That is, in the former case, although the power cannot be adjusted for each phase, there is an advantage that the device cost of the power conversion unit can be reduced. In the latter case, although the device cost of the power conversion unit increases, there is an advantage that the power can be adjusted for each phase.

  Therefore, in the present application, a power conversion unit having a single power conversion circuit unit is employed for the connection between the power generation device and the AC line, and two power conversions are performed for the connection between the auxiliary power supply device and the AC line. It was decided to construct a distributed power supply system that employs a power conversion unit having a circuit unit. And the subject in the case of operating such a distributed power supply system was considered.

  FIG. 4 is a diagram for explaining an operation example of the distributed power supply system. Specifically, this is an example showing how much power is supplied from the auxiliary power supply device 10 and the power generation device 20 to the power consumption device 30. However, the rated supply power of the power generation apparatus 20 is 700 W (350 W for one phase), and the rated output power of the auxiliary power supply 10 is 1200 W for one phase (2400 W for both phases). Further, since the voltage between the first voltage line 2a and the neutral line 2c and the voltage between the second voltage line 2b and the neutral line 2c are both AC100V, the current value shown in the figure and the AC100V Is the power value described in the figure.

FIG. 4A is an example when the demand power of the first consumer 31 and the demand power of the second consumer 32 constituting the power consumer 30 are both 650 W (1300 W in total for both phases). Here, the internal configuration of the power generation device 20 and the auxiliary power supply device 10 shown in FIG. 4 is as shown in FIG.
In this case, the power generation control unit 22 of the power generation apparatus 20 includes the first connection point P1 passing through the first voltage line 2a and the first connection point P1 through the second voltage line 2b and the power traveling from the first connection point P1 side to the second connection point P2. The same power is supplied to the first voltage line 2a and the second voltage line 2b so that the total power with the power directed from the side toward the second connection point P2 is minimized and does not become negative power. Control generated power. Specifically, 350 W of power is supplied to the first voltage line 2a, and 350 W of power is supplied to the second voltage line 2b. However, even if a total of 700 W corresponding to the rated supply power is supplied from the power generation device 20, it does not reach 1300 W, which is the demand power of the power consuming device 30.

As a result, the insufficient power in the first consumption unit 31 (that is, the power traveling from the first connection point P1 side to the second connection point P2 through the first voltage line 2a) is 300 W, and the insufficient power in the second consumption unit 32 (That is, the electric power passing from the first connection point P1 side to the second connection point P2 through the second voltage line 2b) is 300W.
And by outputting these electric power of 300W each from the auxiliary power supply device 10, the electric power which goes to the 1st connection location P1 from the electric power grid | system 1 side through the 1st voltage line 2a becomes zero, and the 2nd voltage line 2b is used. The power passing through the power system 1 side to the first connection point P1 becomes zero.

  Next, FIG. 4B shows that the demand power of the first consumption unit 31 constituting the power consumption device 30 is 1200 W and the demand power of the second consumption unit 32 is 100 W (1300 W in total for both phases). It is an example in the case of.

  Also in this case, the power generation control unit 22 of the power generation device 20 uses the first voltage line 2a through the first voltage line 2a and the first connection point through the second voltage line 2b. The same power is supplied to the first voltage line 2a and the second voltage line 2b so that the total power with the power from the P1 side toward the second connection point P2 is minimized and does not become negative power. To control the generated power. Specifically, 350 W of power is supplied to the first voltage line 2a, and 350 W of power is supplied to the second voltage line 2b. However, even if a total of 700 W corresponding to the rated supply power is supplied from the power generation device 20, it does not reach 1300 W, which is the demand power for power consumption.

  However, in the example shown in FIG. 4B, between the first power consumption 1200W between the first voltage line 2a and the neutral line 2c, and between the second voltage line 2b and the neutral line 2c. This is different from the second power consumption of 100 W. As a result, when the same power (350 W for each) is supplied from the power generator 20 to the first voltage line 2a and the second voltage line 2b, the first connection point P1 side passes through the first voltage line 2a. The power going to the second connection point P2 and the power going to the second connection point P2 from the first connection point P1 side through the second voltage line 2b are different. That is, in the example shown in FIG. 4B, the power passing through the first voltage line 2a from the first connection location P1 side to the second connection location P2 is +850 W (insufficient power), and the second voltage line 2b As for the electric power which goes to the 2nd connection location P2 from the 1st connection location P1 side through, it will be -250W (surplus power), and the sign of both powers will differ.

  In such a case, since the surplus power of −250 W is generated, no power is output from the auxiliary power supply 10 to the second voltage line 2b, and the above-described insufficient power is supplied from the auxiliary power supply 10 to the first voltage line 2a. When 850 W is output, the power passing through the first voltage line 2a from the power system 1 side to the first connection point P1 becomes zero (0 W). In addition, when the auxiliary power supply device 10 is mainly intended to output power in one direction from the power storage unit 12 to the AC line 2, the power conversion unit 13 performs conversion of output power from the power storage unit 12 to the AC line 2. However, it is not necessary to convert power in the reverse direction from the AC line 2 to the power storage unit 12. That is, since the power conversion unit 13 does not need to have bidirectionality, the semiconductor switching element to be used may not have bidirectionality. That is, charging of the power storage unit 12 is performed using a circuit (not shown) different from the power conversion unit 13. Therefore, when the power conversion unit 13 can only convert the output power in one direction from the power storage unit 12 to the AC line 2, the second connection point from the first connection point P1 through the second voltage line 2b. The power going to P2 remains -250W (surplus power). As a result, the total power of the power traveling from the power system 1 side to the first connection point P1 through the first voltage line 2a and the power traveling from the power system 1 side to the first connection point P1 through the second voltage line 2b Becomes negative power (−250 W). That is, a reverse power flow of 250 W is generated in the power system 1, but only a power generated using natural energy, such as power obtained by solar power generation or power obtained by wind power generation, generally has a reverse power flow. In the situation where it is not recognized, there is a problem that the reverse flow of the power from the power generation device 20 and the power from the auxiliary power supply device 10 as described above is not recognized.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a distributed power supply system capable of preventing the occurrence of reverse power flow to the power system.

In order to achieve the above object, the distributed power system according to the present invention is characterized by a single-phase, three-wire AC having a first voltage line, a second voltage line, and a neutral line connected to a power system. An auxiliary power supply connected to the AC line at a first connection location, a power generator connected to the AC line at a second connection location, and the second connection location of the AC line. A power consuming device to be connected, and the first connection point and the second connection point are arranged in the arrangement order toward the downstream side when viewed from the connection point of the power system with respect to the AC line. Type power supply system,
When the power going from the power system side to the power consuming device is positive power, at the time of non-power failure that can supply power to the AC line from the power system,
The power generation device includes: a power generation unit; electric power passing from the first connection location side to the second connection location through the first voltage line; and the first connection location side from the first connection location side through the second voltage line. The power generation unit is configured to supply the same power to the first voltage line and the second voltage line so that the total power with the power toward the two connection points is minimized and does not become negative power. A power generation control unit for controlling generated power;
The auxiliary power supply device includes a power storage unit, a positive / negative sign of power passing from the first connection location side to the second connection location through the first voltage line, and the first connection through the second voltage line. When the positive and negative signs of the power going from the location side to the second connection location are different from each other, the power going from the power system side to the first connection location through the first voltage line and the second voltage line are passed. The output power from the power storage unit to the first voltage line and the second voltage line is not less than zero so that the total power with the power from the power system side to the first connection point does not become negative power It has the point which has the operation control part which adjusts to each value separately.

According to the above characteristic configuration, the operation control unit of the auxiliary power supply device has the first connection point from the power system side through the second voltage line and the power going from the power system side to the first connection point through the first voltage line. The output power from the power storage unit to the first voltage line and the second voltage line is individually adjusted to a value of zero or more so that the total power with the power going to the negative power does not become negative power. That is, the situation where the total power of the power traveling from the power system side to the first connection location through the first voltage line and the power traveling from the power system side to the first connection location through the second voltage line is negative power That is, it is possible to prevent a situation in which reverse power flow occurs.
In addition, the first connection point and the second connection point are provided in the arrangement order toward the downstream side when viewed from the connection point of the electric power system with respect to the AC line, and the power generation control unit of the power generation device has the first voltage. The total power of the power passing through the line from the first connection location side to the second connection location and the power passing through the second voltage line from the first connection location side to the second connection location is minimized and negative power The generated power of the power generation unit is controlled so that it does not occur. In other words, the power generator operates with the maximum generated power to cover the demand power of the power consuming device. Then, the auxiliary power supply device operates so as to supplementarily output electric power that cannot be covered by the power generation device. As described above, the distributed power supply system having this characteristic configuration is preferable in that the power generation apparatus can be operated at a high operation rate and the load on the auxiliary power supply apparatus is reduced. For example, if the power generation device has a higher power generation efficiency than the grid power, such as a solid oxide fuel cell, or a cogeneration device that combines the engine and generator to obtain heat and power, the power generation efficiency and exhaust When the total efficiency combined with the thermal efficiency is higher than the power generation efficiency of the grid power, there is an advantage that the operation merit (energy saving) becomes high if the power generation device can be operated at a high operation rate. In addition, when the power storage unit of the auxiliary power supply device is set to store electricity at night (that is, a time zone where electricity charges are low) and to discharge during the daytime (that is, a time zone where electricity charges are high), for example, There is an advantage that the driving merit (economic efficiency) becomes higher than the case where there is no.
Therefore, it is possible to provide a distributed power supply system capable of preventing the occurrence of reverse power flow to the power system while supplying power to the power consuming device.

  Another characteristic configuration of the distributed power supply system according to the present invention is that the operation control unit of the auxiliary power supply device is configured such that the sign of the power going from the first connection location to the second connection location is negative. The output voltage from the power storage unit to one voltage line or the second voltage line is adjusted to zero, and the first voltage having a positive sign from the first connection point to the second connection point is positive Output power from the power storage unit to the line or the second voltage line, the power going from the power system side to the first connection point through the first voltage line and the power passing through the second voltage line It is in the point which adjusts so that the total electric power with the electric power which goes to the said 1st connection location from the system | strain side may become the minimum, and it may not become negative electric power.

  According to the above characteristic configuration, the operation control unit of the auxiliary power supply device sets the output power from the power storage unit to the negative sign to zero, and the power flowing from the first connection point to the second connection point. By adjusting the output power to the first voltage line or the second voltage line with the positive sign, the power and the second voltage line passing from the power system side to the first connection point through the first voltage line It is possible to minimize the total power with the power passing through the power system from the power system side to the first connection location and not to be negative power. As a result, it is possible to prevent reverse power flow to the power system while supplying power to the power consuming device.

  Still another characteristic configuration of the distributed power supply system according to the present invention is that the operation control unit of the auxiliary power supply device includes the power passing from the power system side to the first connection location through the first voltage line, and The first voltage line and the first voltage from the power storage unit are minimized so that the total power of the power going from the power system side to the first connection point through the second voltage line is minimized and does not become negative power. The output power for the two voltage lines is adjusted to the same value.

  According to the above characteristic configuration, the operation control unit of the auxiliary power supply device adjusts the output power from the power storage unit to the first voltage line and the second voltage line to the same value, and passes through the first voltage line to the power system side. The total power of the power going from the power source to the first connection location and the power going from the power system side to the first connection location through the second voltage line can be minimized and not negative power. As a result, it is possible to prevent reverse power flow to the power system while supplying power to the power consuming device. Furthermore, since output is performed from the power storage unit to both the first voltage line and the second voltage line, the output power from the power storage unit is greater than when output is performed only to one of the first voltage line and the second voltage line. Can be increased. As a result, it is possible to reduce the power supplied from the power system (that is, the power purchased).

It is a figure which shows the structure of a distributed power supply system. It is a figure explaining the example of operation of the distributed power supply system of this embodiment. It is a figure explaining the example of operation of the distributed power supply system of this embodiment. It is a figure explaining the operation example of the distributed power supply system of a comparative example.

A distributed power supply system according to the present invention will be described below with reference to the drawings. FIG. 1 is a diagram illustrating a configuration of a distributed power supply system.
This distributed power system includes a single-phase three-wire AC line 2 having a first voltage line 2a, a second voltage line 2b, and a neutral line 2c connected to the power system 1, and an AC line 2. Auxiliary power supply device 10 having power storage unit 12 connected at first connection point P1, power generation device 20 connected to AC line 2 at second connection point P2, and third connection to AC line 2 And a power consuming device 30 connected at the point P3. A first connection point P1, a second connection point P2, and a third connection point P3 are provided in the arrangement order toward the downstream side when viewed from the connection point of the power system 1 to the AC line 2. In FIG. 1, the power consuming device 30 can be regarded as connected to the second connection location P2. That is, it can be considered that both the power generation device 20 and the power consumption device 30 are connected to the AC line 2 at the second connection point P2.

  In the present embodiment, power directed from the power system 1 side to the power consuming device 30 is assumed to be positive power. Further, consider a case of non-power failure that allows power supply from the power system 1 to the AC line 2.

  In the example of the present embodiment, the voltage between the first voltage line 2a and the neutral line 2c is AC100V, and the voltage between the second voltage line 2b and the neutral line 2c is also AC100V. Further, the voltage between the first voltage line 2a and the second voltage line 2b is AC200V. In FIG. 1, as the power consuming device 30, the first consumption unit 31 as a 100 V load connected between the first voltage line 2 a and the neutral line 2 c, the second voltage line 2 b, and the neutral line 2 c And a second consumer 32 as a 100V load connected between the two.

[Power generation device 20]
The power generation device 20 includes a power generation unit 21 and a power generation control unit 22 that controls the power generated by the power generation unit 21 (that is, the power supplied to the AC line 2). The power generation unit 21 can be configured using a device capable of controlling its own generated power, such as a fuel cell or a generator that operates by the driving force of the engine. Although illustration is omitted, the power generation device 20 also includes a power conversion unit for converting the power generated by the power generation unit 21 into a desired voltage, frequency, phase, and the like and supplying the converted power to the AC line 2.

  The control of the generated power by the power generation control unit 22 will be described. The power generation control unit 22 passes the first voltage line 2a through the second voltage line 2b and the power traveling from the first connection point P1 side to the second connection point P2. Thus, the first voltage line 2a and the second voltage are set so that the total power with the power from the first connection point P1 to the second connection point P2 is minimized and does not become negative power (that is, no reverse power flow). The generated power is controlled so as to supply the same power to the line 2b. The power generation control unit 22 of the power generation apparatus 20 includes power that travels from the first connection point P1 side to the second connection point P2 through the first voltage line 2a, and from the first connection point P1 side through the second voltage line 2b. With reference to the detection result of a current transformer (not shown), the electric power traveling toward the second connection point P2 (that is, the first connection point P1 and the second connection on the first voltage line 2a and the second voltage line 2b). Monitoring (see the power that can be derived based on the value of the current flowing between the points P2).

[Auxiliary power supply 10]
The auxiliary power supply 10 includes a power storage unit 12 that can store electricity, a power conversion unit 13 that can adjust output power from the power storage unit 12 to the AC line 2, and an operation control that controls the operation of the power conversion unit 13. Part 11. The operation control unit 11 of the auxiliary power supply device 10 includes power that travels from the first connection point P1 side to the second connection point P2 through the first voltage line 2a, and the first connection point P1 side through the second voltage line 2b. To the second connection point P2 from the power system 1 side through the first voltage line 2a to the first connection point P1 from the power system 1 side, the first connection from the power system 1 side through the second voltage line 2b With reference to the detection result of a current transformer (not shown), the electric power going to the point P1 (that is, on the first voltage line 2a and the second voltage line 2b closer to the power system 1 than the first connection point P1) Refer to the power that can be derived based on the current value that flows through the first voltage line 2a and the second voltage line 2b between the first connection point P1 and the second connection point P2 Monitoring).

  The power storage unit 12 can be composed of various devices having a power storage function, such as a storage battery (chemical battery) or an electric double layer capacitor.

  The power conversion unit 13 includes a set composed of the first DC / DC converter circuit 14a and the first inverter circuit 15a and a pair composed of the second DC / DC converter circuit 14b and the second inverter circuit 15b. A set of the first DC / DC converter circuit 14a and the first inverter circuit 15a is connected between the power storage unit 12, the first voltage line 2a, and the neutral line 2c. As a result, the first voltage line 2a and the neutral line are connected. The output power to and from 2c can be adjusted. The set of the second DC / DC converter circuit 14b and the second inverter circuit 15b is connected between the power storage unit 12, the second voltage line 2b, and the neutral line 2c. As a result, the second voltage line 2b and the neutral line are connected. The output power to and from 2c can be adjusted. The first DC / DC converter circuit 14a, the first inverter circuit 15a, the second DC / DC converter circuit 14b, and the second inverter circuit 15b are configured using a semiconductor switching element or the like. The operation control unit 11 controls the switching operation of the semiconductor switching element. That is, the operation control unit 11 controls the output power from the power storage unit 12 to the AC line 2.

  In the present embodiment, in order to insulate the AC line 2 from the power storage unit 12, at least one of the first DC / DC converter circuit 14a and the first inverter circuit 15a has an insulating circuit configuration. At least one of the 2DC / DC converter circuit 14b and the second inverter circuit 15b has an insulating circuit configuration. In addition, in the present embodiment, the main purpose is to output power in one direction from the power storage unit 12 to the AC line 2, and thus the first DC / DC converter circuit 14 a and the second DC / DC converter circuit 14 b are connected from the power storage unit 12. It is only necessary to convert the output power to the AC line 2, and it is not necessary to convert the power in the reverse direction from the AC line 2 to the power storage unit 12. That is, since the first DC / DC converter circuit 14a and the second DC / DC converter circuit 14b do not need to have bidirectionality, the cost required for manufacturing the circuit can be reduced.

Furthermore, in the distributed power supply system according to the present embodiment, the operation control unit 11 of the auxiliary power supply device 10 has positive and negative signs of power traveling from the first connection point P1 side to the second connection point P2 through the first voltage line 2a. And the first connection from the power system 1 side through the first voltage line 2a when the positive and negative signs of the power traveling from the first connection point P1 side to the second connection point P2 through the second voltage line 2b are different from each other. The first voltage line 2a is connected from the power storage unit 12 so that the total power of the power going to the location P1 and the power going from the power system 1 side to the first connection location P1 through the second voltage line 2b does not become negative power. The output power for the second voltage line 2b is adjusted to a value of zero or more.
The contents of this control will be described below with a specific example.

  FIG. 2 is a diagram for explaining an operation example of the distributed power supply system. Specifically, FIG. 2 is a diagram for explaining an operation example of the operation control unit 11 of the auxiliary power supply device 10. However, the rated supply power of the power generation apparatus 20 is 700 W (350 W for one phase), and the rated output power of the auxiliary power supply 10 is 1200 W for one phase (2400 W for both phases). This assumption is similar to that previously described with respect to FIG. Further, since the voltage between the first voltage lines 2a, 2b and the neutral line 2c is AC100V, the product of the current value and AC100V shown in the figure becomes the power value shown in the figure.

  FIG. 2A shows the case where the demand power of the first consumption unit 31 constituting the power consumption device 30 is 1200 W and the demand power of the second consumption unit 32 is 100 W (1300 W in total for both phases). It is an example.

  In this case, the power generation control unit 22 of the power generation apparatus 20 includes the first connection point P1 passing through the first voltage line 2a and the first connection point P1 through the second voltage line 2b and the power traveling from the first connection point P1 side to the second connection point P2. The same power is supplied to the first voltage line 2a and the second voltage line 2b so that the total power with the power directed from the side toward the second connection point P2 is minimized and does not become negative power. Control generated power. In this example, the power generation apparatus 20 supplies 350 W of power to the first voltage line 2a and supplies 350 W of power to the second voltage line 2b. However, even if that much power (700 W in total) is supplied from the power generation device 20, it does not reach 1300 W, which is the demand power of the power consumption device 30. Further, when the same power (350 W) is supplied from the power generation device 20 to the first voltage line 2a and the second voltage line 2b, the second connection point P2 from the first connection point P1 side through the first voltage line 2a. The sign of the power going to the second connection place differs from the sign of the power going to the second connection place P2 from the first connection point P1 side through the second voltage line 2b. Specifically, in the example shown in FIG. 2A, the power passing from the first connection point P1 side to the second connection point P2 through the first voltage line 2a is +850 W, and the second voltage line 2b is connected to the second voltage line 2b. The electric power passing through the first connection point P1 from the first connection point P1 side to the second connection point P2 is -250 W, and the signs of the powers of the two are different.

  In this way, the positive and negative signs of the power passing from the first connection point P1 side to the second connection point P2 through the first voltage line 2a and the second connection point from the first connection point P1 side through the second voltage line 2b. When the positive and negative signs of the power going to P2 are different from each other, the operation control unit 11 of the auxiliary power supply device 10 uses the first voltage line 2a and the power and the second voltage going from the power system 1 side to the first connection point P1. The first voltage line 2a is connected from the power storage unit 12 so that the total power of the power flowing from the power system 1 side to the first connection point P1 through the line 2b does not become negative power (that is, so as not to flow backward). The output power for the second voltage line 2b is adjusted to a value of zero or more. In the present embodiment, the operation control unit 11 of the auxiliary power supply device 10 includes the first voltage line 2a or the second voltage line in which the sign of the power going from the first connection point P1 to the second connection point P2 is negative. The output power to 2b is adjusted to zero, and the output power to the first voltage line 2a or the second voltage line 2b in which the sign of the power going from the first connection point P1 to the second connection point P2 is positive, The total power of the power traveling from the power system 1 side to the first connection point P1 through the first voltage line 2a and the power traveling from the power system 1 side to the first connection point P1 through the second voltage line 2b is minimized. And adjust so that it does not become negative power.

Specifically, as shown in FIG. 2A, the operation control unit 11 outputs 600 W from the auxiliary power supply device 10 to the first voltage line 2a, and the auxiliary power supply device 10 and the second voltage line 2b. Output control is performed so that output is not performed between As a result, the power traveling from the power system 1 side to the first connection point P1 through the first voltage line 2a becomes +250 W, and the power traveling from the power system 1 side to the first connection point P1 through the second voltage line 2b Becomes −250 W, and their total power becomes zero (0 W).
Therefore, reverse power flow to the power system 1 can be prevented.

  Next, another example of output control by the operation control unit 11 will be described with reference to FIG. In addition, this case is also an example in which the demand power of the first consumption unit 31 constituting the power consumption device 30 is 1200 W and the demand power of the second consumption unit 32 is 100 W (1300 W in total for both phases). .

  Also in the example shown in FIG. 2B, the power generation control unit 22 of the power generation device 20 transmits the power and the second voltage line 2b from the first connection point P1 side to the second connection point P2 through the first voltage line 2a. Identical to the first voltage line 2a and the second voltage line 2b so that the total power with the power passing through the first connection point P1 side to the second connection point P2 is minimized and does not become negative power The generated power is controlled so as to supply electric power. Specifically, 350 W of power is supplied to the first voltage line 2a, and 350 W of power is supplied to the second voltage line 2b. As a result, the power going from the first connection point P1 side to the second connection point P2 through the first voltage line 2a is +850 W, and the second connection point from the first connection point P1 side through the second voltage line 2b. As for the electric power which goes to P2, the sign of both electric powers differs like -250W.

In this case, the operation control unit 11 of the auxiliary power supply device 10 receives the power from the power system 1 side through the first voltage line 2a toward the first connection point P1 and the second voltage line 2b from the power system 1 side. The output power from the power storage unit 12 to the first voltage line 2a and the second voltage line 2b is adjusted to the same value so that the total power with the power toward the one connection point P1 is minimized and does not become negative power. .
Specifically, as illustrated in FIG. 2B, the operation control unit 11 outputs 300 W from the auxiliary power supply device 10 to the first voltage line 2 a, and from the auxiliary power supply device 10 to the second voltage line 2 b. Also outputs 300W. As a result, the power going from the power system 1 side to the first connection point P1 through the first voltage line 2a becomes +550 W, and the power going from the power system 1 side to the first connection point P1 through the second voltage line 2b Becomes −550 W, and their total power becomes zero (0 W).
Therefore, also in the case of the operation example shown in FIG. 2B, the reverse power flow to the power system 1 can be prevented.

  FIG. 3 is a diagram for explaining an operation example of the distributed power supply system of the present embodiment. Specifically, the demand power of the first consumer 31 constituting the power consumer 30 is 3100 W and the second consumer This is an example when the power demand of the unit 32 is 100 W (3200 W in total for both phases). FIG. 3A shows an example in which the same control method as in FIG. 2A is used, and FIG. 3B shows the same control as in FIG. 2B. This is an example of using the technique. As in the case described with reference to FIG. 2, the rated supply power of the power generator 20 is 700 W (350 W for one phase), and the rated output power of the auxiliary power supply 10 is 1200 W for one phase (2400 W for both phases). To do.

  In the case illustrated in FIG. 3A, the power generation control unit 22 of the power generation device 20 transmits the power and the second voltage line 2b from the first connection point P1 side to the second connection point P2 through the first voltage line 2a. Identical to the first voltage line 2a and the second voltage line 2b so that the total power with the power passing through the first connection point P1 side to the second connection point P2 is minimized and does not become negative power The generated power is controlled so as to supply electric power. Specifically, the power generator 20 supplies 350 W of power to the first voltage line 2a and supplies 350 W of power to the second voltage line 2b. As a result, the power going from the first connection point P1 side to the second connection point P2 through the first voltage line 2a is +2750 W, and the second connection point from the first connection point P1 side through the second voltage line 2b. As for the electric power which goes to P2, the sign of both electric powers differs like -250W.

In this case, when a control method similar to that shown in FIG. 2A is used, the operation control unit 11 is 1200 W (rated output power) from the auxiliary power supply 10 to the first voltage line 2a as shown in FIG. The output control is performed so that the output is not performed between the auxiliary power supply device 10 and the second voltage line 2b. As a result, the power going from the power system 1 side to the first connection point P1 through the first voltage line 2a becomes + 1550W, and the power going from the power system 1 side to the first connection point P1 through the second voltage line 2b Becomes −250 W, and the total power, that is, the power supplied from the power system 1 becomes +1300 W.
Accordingly, although the reverse power flow to the power system 1 can be prevented, the power supplied from the power system 1 becomes large.

On the other hand, in the example shown in FIG. 3B, the operation control unit 11 outputs 1200 W from the auxiliary power device 10 to the first voltage line 2a, and the auxiliary voltage device 10 outputs the second voltage line 2b. Also outputs 1200W. As a result, the power going from the power system 1 side to the first connection point P1 through the first voltage line 2a becomes + 1550W, and the power going from the power system 1 side to the first connection point P1 through the second voltage line 2b Becomes −1450 W, and the total power, that is, the power supplied from the power system 1 becomes +100 W.
Accordingly, reverse power flow to the power system 1 can be prevented, and power supplied from the power system 1 can be reduced.

<Another embodiment>
In the above embodiment, the operation example of the operation control unit 11 of the auxiliary power supply device 10 has been described with specific numerical values. However, these numerical values are described for the purpose of illustration, and the present invention includes those numerical values. It is not limited. In addition, the voltage between the first voltage line 2a and the neutral line 2c and the voltage between the second voltage line 2b and the neutral line 2c are limited to AC100V exemplified in the above embodiment. It is not a thing.

  INDUSTRIAL APPLICABILITY The present invention can be used for a distributed power supply system for preventing the occurrence of reverse power flow to a power system.

DESCRIPTION OF SYMBOLS 1 Electric power system 2 AC line 2a 1st voltage line 2b 2nd voltage line 2c Neutral line 10 Auxiliary power supply device 11 Operation control part 12 Power storage part 13 Power conversion part 14a 1st DC / DC converter circuit 14b 2nd DC / DC converter circuit 15a First inverter circuit 15b Second inverter circuit 20 Power generation device 21 Power generation unit 22 Power generation control unit 30 Power consumption device 31 First consumption unit 32 Second consumption unit P1 First connection location P2 Second connection location P3 Third connection location

Claims (3)

A single-phase three-wire AC line having a first voltage line, a second voltage line, and a neutral line connected to the power system, and an auxiliary power supply device connected to the AC line at a first connection location And a power generation device connected to the AC line at a second connection location, and a power consuming device connected to the second connection location of the AC line, the power system for the AC line A distributed power supply system in which the first connection portion and the second connection portion are provided in the arrangement order toward the downstream side when viewed from a connection portion,
When the power going from the power system side to the power consuming device is positive power, at the time of non-power failure that can supply power to the AC line from the power system,
The power generation device includes: a power generation unit; electric power passing from the first connection location side to the second connection location through the first voltage line; and the first connection location side from the first connection location side through the second voltage line. The power generation unit is configured to supply the same power to the first voltage line and the second voltage line so that the total power with the power toward the two connection points is minimized and does not become negative power. A power generation control unit for controlling generated power;
The auxiliary power supply device includes a power storage unit, a positive / negative sign of power passing from the first connection location side to the second connection location through the first voltage line, and the first connection through the second voltage line. When the positive and negative signs of the power going from the location side to the second connection location are different from each other, the power going from the power system side to the first connection location through the first voltage line and the second voltage line are passed. The output power from the power storage unit to the first voltage line and the second voltage line is not less than zero so that the total power with the power from the power system side to the first connection point does not become negative power A distributed power supply system having an operation control unit that individually adjusts values. The operation control unit of the auxiliary power supply device is
Adjusting the output power from the power storage unit to the first voltage line or the second voltage line of which the sign of power going from the first connection point to the second connection point is negative, to zero,
The output power from the power storage unit to the first voltage line or the second voltage line of which the sign of power going from the first connection point to the second connection point is positive, the first voltage line The total power of the power passing through the power system side from the power system side to the first connection location and the power passing through the second voltage line from the power system side to the first connection location is minimized and negative power. The distributed power supply system according to claim 1, wherein the distributed power supply system is adjusted so as not to fall. The operation control unit of the auxiliary power supply device is
The total power of the power passing through the first voltage line from the power system side to the first connection location and the power passing through the second voltage line from the power system side to the first connection location is minimized. 2. The distributed power supply system according to claim 1, wherein output powers from the power storage unit to the first voltage line and the second voltage line are adjusted to the same value so as not to become negative power.

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