JP4457190B2 - Power generation system - Google Patents

Description

  The present invention relates to a power generation system, and more particularly to a system that prevents a reverse flow phenomenon in which generated power of the system flows out to a commercial power source.

  A hot water supply device is installed in the power generation device to supply the electric power generated by the power generation device to the electrical equipment, and a part of the heat source supplied to the heat utilization terminal connected to the hot water supply device is covered by exhaust heat generated by power generation. A power generation system has been developed.

  Such systems are driven by a motor such as a gas engine, gas turbine, or diesel engine to generate power, and use a motor type that uses exhaust heat generated by the motor, or chemically generate hydrogen and oxygen. A fuel cell type that generates electricity by reacting and uses the reaction heat as exhaust heat has been developed.

In such a system, the output of the power generator is directly connected to the commercial power supply, and the output voltage is controlled so as to follow the voltage of the commercial power supply. Is operated with commercial power. For this reason, when the power consumption of the electrical equipment is reduced, the power generated by the power generation device becomes excessive, and the surplus power flows backward to the commercial power supply side, causing a harmful effect.
Therefore, various technical standards have been formulated such as preventing a single operation by setting the maximum allowable backflow time to 350 mS in order to suppress adverse effects caused by the backflow of power to the commercial power source.

By the way, as a technique for preventing the backflow of electric power to the commercial power source, Patent Document 1 discloses a method for adjusting the load of an electric device connected to the commercial power source.
The load adjustment method disclosed in Patent Literature 1 sets a power consumption adjustment device in advance, and forcibly operates a part or all of the power consumption adjustment device when the total power consumption of the electrical device is lower than the generated power of the power generation device. By doing so, electric power exceeding the generated electric power is consumed to prevent backflow. By employing the load adjustment method disclosed in Patent Document 1, it is possible to effectively prevent the backflow of power to the commercial power supply side.
JP 2003-153449 A

However, the backflow of electric power to the commercial power source occurs not only due to load fluctuation as disclosed in Patent Document 1, but also due to a voltage drop of the commercial power source.
Here, when the commercial power supply causes a voltage drop, the current supplied to the electrical equipment decreases approximately in proportion to the voltage drop, and the power consumption decreases approximately in proportion to the square of the voltage drop. For example, in an electrical device that consumes 600 W of power at the rated voltage (100 V), when the voltage drops to 50 V, the energizing current is reduced to 3 A, and the power consumption is reduced to 150 W, which is 1/4.

For this reason, there is a problem that even if the power does not flow back to the commercial power supply side at the rated voltage, the total power consumption by the electric equipment is reduced due to the voltage drop and the backflow occurs.
In other words, the backflow of power to the commercial power source side is caused not only by the load fluctuation as described in Patent Document 1, but also caused by the voltage drop of the commercial power source even when the load is constant, which is effective. A countermeasure was desired.

  This invention is proposed in view of the said situation, and it aims at providing the electric power generation system which prevents the backflow of the generated electric power to the commercial power source side effectively, even when the voltage drop of a commercial power source arises.

  The invention according to claim 1, which is proposed to achieve the above object, has a power generation unit and a heat supply unit having a heat source, and supplies power generated by the power generation unit to an electric device and is generated by power generation. In a power generation system that supplies exhaust heat and heat generated by a heat supply unit to a heat utilization terminal, a voltage detection unit that detects a voltage of a commercial power source drawn from outside, and the power generation when the commercial power source has a rated voltage value A main surplus power consuming unit capable of consuming power exceeding the output power of the unit, and a sub surplus power consuming unit for assisting power consumption of the main surplus power consuming unit, wherein the power generating unit is connected to the commercial power source. The output voltage and the phase thereof are matched to the commercial power supply, and constant current power generation is performed to control the output current to a predetermined rated current value. The voltage detected by the voltage detection unit is less than a preset threshold value. In When beat is configured to forcibly connected in addition to the main surplus power consuming unit sub surplus power consuming unit as a load.

According to the present invention, the power generation unit has its output voltage and phase follow the commercial power supply, and its output current is constant-current controlled to a predetermined rated current value.
Therefore, it is possible to easily calculate the voltage of the commercial power source when the current consumption of the main surplus power consumption unit coincides with the output current of the power generation unit with the voltage drop of the commercial power source.

For example, when the output current of the power generation unit is 5 A and the main surplus power consumption unit is a 600 W load at the rated voltage (100 V), the current consumption of the main surplus power consumption unit decreases to 5 A when the commercial power supply decreases to about 83 V. Thus, it matches the output current of the power generation unit.
Therefore, it can be seen that when the commercial power supply drops below approximately 83V, the output power (output current) of the power generation unit cannot be consumed by the main surplus power consumption unit.

According to the present invention, when the voltage value calculated in advance in this way is set as a threshold value, and the detected voltage of the commercial power supply by the voltage detection unit falls below the threshold value, the sub-voltage is added to the total load of the main surplus power consumption unit. The surplus power consumption unit is forcibly connected as a load.
In other words, according to the present invention, when the detection voltage of the commercial power supply is equal to or higher than the threshold, it is determined that the output power of the power generation unit can be consumed only by the main surplus power consumption unit, and only the main surplus power consumption unit is determined. Control connection. However, when the detection voltage of the commercial power supply falls below the threshold, it is determined that there is a possibility that the output power of the power generation unit cannot be consumed only by the main surplus power consumption unit, and the sub surplus power consumption unit is forced Control to connect.

  As a result, even if the voltage drop of the commercial power supply occurs momentarily or for a long time, and the output power of the power generation unit cannot be consumed by the main surplus power consumption unit alone, the power that cannot be consumed is the sub surplus. It can be consumed by the power consuming unit and the output power of the power generation unit can be consumed completely, and the generated power of the power generation unit is prevented from flowing back to the commercial power source side.

  In the present invention, the auxiliary surplus power consuming unit may be formed with a dedicated load only for consuming power, or a load or device included in the heat supply unit that is used for other purposes. It is good also as a structure to divert. By diverting the load and equipment of the heat supply unit, a dedicated load for the sub-surplus power consumption unit is not required, and cost saving is achieved while effectively preventing backflow of power due to sudden voltage drop of the commercial power supply. be able to.

  According to a second aspect of the present invention, in the power generation system according to the first aspect, a connection load value of the main surplus power consuming unit is equal to or greater than a preset load threshold value, and a commercial power supply by the voltage detection unit is provided. When the detected voltage drops below the threshold, the sub surplus power consumption unit is forcibly connected as a load in addition to the main surplus power consumption unit.

  Here, for example, the case where the output current of the power generation unit is 5 A, the maximum power consumption at the rated voltage of the main surplus power consumption unit is 600 W, and a 300 W electric device is operated while the system is operating will be considered. In this case, even if the commercial power supply drops to 90 V, a current of 5.4 A can be consumed by both the electrical equipment and the main surplus power consumption unit if the load of the main surplus power consumption unit is connected by 300 W. Further, even if the commercial power supply is reduced to 70 V, if the load of the main surplus power consumption unit is increased to 500 W, a current of 5.6 A can be consumed together with the electric equipment. Furthermore, even if the commercial power supply is reduced to 60 V, if the load of the main surplus power consumption unit is increased to 600 W, a current of 5.4 A can be consumed together with the electric equipment.

  However, according to the first aspect of the present invention, when the voltage of the commercial power supply falls below the threshold value, the sub surplus power consumption unit is connected as a load in addition to the main surplus power consumption unit. For this reason, even if the power consumption of the electrical equipment is high and the load of the main surplus power consuming unit can be increased to prevent backflow, the sub surplus power consuming unit is connected, preventing backflow of power. However, wasteful power consumption increases.

According to the present invention, when the load of the main surplus power consuming unit is equal to or greater than the load threshold, that is, there is no room for the load that can be connected to the main surplus power consuming unit, and the voltage of the commercial power supply decreases below the threshold. Only when the sub surplus power consumption unit is connected.
In other words, when the load of the main surplus power consumption unit is less than the load threshold and there is a margin for the load that can be increased, even if the commercial power source falls below the threshold, the sub surplus power consumption unit is not connected, The decrease in power consumption is compensated by an increase in load connection of the main surplus power consumption unit. Thereby, useless power consumption by the sub surplus power consumption unit is reduced.

  According to a third aspect of the present invention, in the power generation system according to the first aspect, the power generation system further includes a power measuring unit that measures the power consumption of the commercial power source, and the voltage detected by the commercial power source is less than the threshold. And when the measured value of the power measuring unit becomes negative when the full load of the main surplus power consuming unit is connected, the sub surplus power consuming unit is added in addition to the main surplus power consuming unit. It is configured to forcibly connect as a load.

Here, when the power consumption of the commercial power supply is a positive value, the power is supplied from the commercial power supply to the power generation system. Further, when the power consumption of the commercial power source is a negative value, it is a backflow state in which power flows out from the system to the commercial power source side.
Therefore, the power measuring unit that measures the power consumption of the commercial power supply has a function of a backflow detection sensor in which the sign of the power consumption indicates whether there is a backflow of power to the commercial power supply in addition to the function of measuring the power consumption. .

  According to the present invention, by adding a power measurement unit to the configuration of claim 1, there is a possibility that the output power of the power generation unit cannot be consumed by the main surplus power consumption unit alone, and the main surplus power consumption unit Even when the power is connected, the sub surplus power consuming unit is forcibly connected as a load in addition to the main surplus power consuming unit only when the power flows back to the commercial power source due to the low power consumption of the electrical equipment.

  In other words, even if there is a possibility that the main surplus power consumption unit alone cannot consume the output power of the power generation unit, if the power consumption of the electrical equipment is high and there is no backflow of power to the commercial power supply side, the sub surplus The power consumption unit is not connected. Therefore, it is possible to avoid wasteful power consumption by the auxiliary surplus power consuming unit when there is no backflow of power to the commercial power supply side, while preventing power backflow to the commercial power supply side Can be reduced.

  According to a fourth aspect of the present invention, in the power generation system according to any one of the first to third aspects, the auxiliary surplus power consumption unit is configured to include a plurality of loads that can be intermittently connected, and A plurality of loads are connected in stages according to at least one of a connection load value of the surplus power consumption unit and a voltage value of the commercial power source detected by the voltage detection unit.

  As described above, when the commercial power supply causes a voltage drop, the main surplus power consumption unit alone may not be able to consume the output power of the power generation unit. However, if a sub surplus power consumption unit that consumes a large amount of power to consume the output power of the power generation unit is connected at a time, the backflow of power to the commercial power supply side is prevented but wasteful power consumption increases.

  According to the present invention, the load of the sub surplus power consumption unit is connected in stages according to at least one of the connection load value of the main surplus power consumption unit and the voltage value of the commercial power supply. Thereby, compared with the structure which interrupts the sub surplus power consumption part with large power consumption at once, the backflow of the electric power to the commercial power source side can be prevented, reducing wasteful power consumption. In particular, when the voltage drop is long, the energy efficiency is greatly improved.

  The invention described in claim 5 includes a power generation unit and a heat supply unit having a heat source, and supplies the generated power of the power generation unit to the electrical equipment, and generates heat in the exhaust heat generated by the power generation and the heat supply unit. In a power generation system that supplies heat to a heat utilization terminal, a voltage detection unit that detects the voltage of a commercial power supply drawn from the outside, and can consume more power than the output power of the power generation unit when the commercial power supply has a rated voltage value A surplus power consumption unit, and the power generation unit is configured to be connected to the commercial power source and to control the output current with a predetermined rated current value as an upper limit while matching the output voltage and its phase with the commercial power source, When the voltage detected by the commercial power supply by the voltage detection unit drops below a preset threshold, the output current of the power generation unit is forcibly reduced from a rated current value to a predetermined limit current value. That.

Here, the inventions according to the first to fourth aspects of the present invention are configured to prevent the backflow of power to the commercial power supply side by connecting the auxiliary surplus power consumption unit to the load.
In contrast, the present invention prevents the backflow of power to the commercial power source by reducing the output current of the power generation unit to a limit current value that can be consumed by the surplus power consumption unit when the voltage of the commercial power source drops. Is.

  According to the present invention, useless power consumption by the auxiliary surplus power consumption unit as in the invention described in claim 1 is avoided, and even if a voltage drop of a commercial power supply occurs instantaneously or for a long time, It is possible to reduce wasteful power consumption while preventing the backflow of power to the commercial power source.

  By the way, according to the present invention, when the voltage of the commercial power supply falls below the threshold value, the output current of the power generation unit is reduced to a limit current value that can be consumed only by the surplus power consumption unit regardless of the power consumption of the electrical equipment. Let For this reason, even when the power consumption of the electrical equipment is high and no reverse flow occurs due to a voltage drop, the output current of the power generation unit is reduced, and the power consumption of the commercial power supply increases.

Therefore, in the present invention, it is also possible to adopt a configuration in which the output current of the power generation unit is not reduced when the connection load value of the surplus power consumption unit is low.
In other words, in the present invention, when the connection load value of the surplus power consumption unit is equal to or higher than a preset load value, and when the voltage detected by the commercial power source by the voltage detection unit falls below the threshold, It is also possible to adopt a configuration in which the output current of the power generation unit is forcibly reduced from the rated current value to a predetermined limit current value.

  According to this configuration, similarly to the invention of claim 2, when the load of the main surplus power consumption unit is equal to or greater than the load threshold, there is no room for a load that can be additionally connected by the main surplus power consumption unit, and Only when the voltage of the commercial power supply drops below the threshold value, the output current of the power generation unit is reduced to the limit current value. As a result, even if the commercial power supply has a voltage drop, it is possible to avoid a reduction in output current when the output power of the power generation unit can be consumed by both the electrical equipment and the main surplus power consumption unit. Wasteful power consumption is reduced.

  According to a sixth aspect of the present invention, in the power generation system according to the fifth aspect of the present invention, the power generation system further includes a power measuring unit that measures power consumption of the commercial power source, and a detected voltage of the commercial power source by the voltage detection unit is less than the threshold value. And when the measured value of the power measurement unit becomes a negative value when the full load of the surplus power consumption unit is connected, the output current of the power generation unit is changed from the rated current value to the limit current value. It is set as the structure reduced forcibly until.

  According to the present invention, by adding a power measurement unit to the configuration of claim 5, there is a possibility that the output power of the power generation unit may not be consumed by the surplus power consumption unit alone, and the surplus power consumption unit is connected. Even so, control is performed to forcibly reduce the output current of the power generation unit to the limit current value only when a backflow of power to the commercial power source occurs due to low power consumption of the electrical equipment.

  In other words, there is a possibility that the output power of the power generation unit cannot be consumed by the main surplus power consumption unit alone, but if the power consumption of the electrical equipment is high and there is no backflow of power to the commercial power supply side, Does not reduce output power (output current). Thereby, it becomes possible to prevent the backflow of the electric power to the commercial power supply side, reducing the power consumption by the commercial power supply.

  According to a seventh aspect of the present invention, in the power generation system according to the fifth or sixth aspect, the power generation unit is configured to be capable of controlling an output current continuously or stepwise, and is detected by the voltage detection unit. According to the voltage value of the commercial power supply, the output current is adjusted and controlled continuously or stepwise.

  As described above, when the commercial power supply causes a voltage drop, the output power of the power generation unit may not be consumed by the surplus power consumption unit alone. However, if the output current of the power generation unit is reduced to a low limit current value so that the output power of the power generation unit can be consumed by the surplus power consumption unit, the amount of power supplied from the power generation unit to the electrical equipment will be significantly reduced. Although the reverse flow of power to the side is prevented, there is a hate that the power supplied by the commercial power supply increases.

  According to the present invention, the output current of the power generation unit is adjusted and controlled continuously or stepwise according to the voltage value of the commercial power supply. As a result, compared with a configuration that reduces the output current to a low limit current value at a stretch, the power supply from the power generation unit to the electrical equipment can be maintained at a high value while preventing the reverse flow of power, and the power consumption of the commercial power supply Can be reduced.

  According to an eighth aspect of the present invention, in the power generation system according to any one of the first to seventh aspects, thermal energy generated with power consumption of the main surplus power consumption unit or the surplus power consumption unit is converted into the heat. It is set as the structure which can be returned to a supply part.

The main surplus power consuming unit (surplus power consuming unit) is a load provided mainly for the purpose of preventing the backflow of power from the power generation unit to the commercial power supply side, and discards the thermal energy generated with power consumption as it is. You can also.
However, the power generation system is a system originally intended to improve the total energy efficiency by supplying the generated power to the electrical equipment and reducing the exhaust heat accompanying the power generation to the heat supply unit. For this reason, it is unfamiliar with the main point of the system to throw away the thermal energy generated in the main surplus power consumption section (surplus power consumption section) as it is.

According to the present invention, it is possible to improve the total energy efficiency by collecting the thermal energy generated in the main surplus power consumption unit or the surplus power consumption unit and returning it to the heat supply unit.
In the present invention, as a configuration for reducing the thermal energy generated in the main surplus power consumption unit (surplus power consumption unit) to the heat supply unit, for example, the generated thermal energy is transmitted to a recovery system for exhaust heat generated by power generation. A configuration or a configuration in which the generated thermal energy is directly transmitted to the heat source system of the heat supply unit can be employed.

According to the first and fifth aspects of the present invention, it is possible to provide a power generation system that effectively prevents the power of the power generation unit from flowing backward to the commercial power source even when a voltage drop of the commercial power source occurs. .
According to invention of Claims 2-4, 6-8, the electric power generation system which improved energy efficiency can be provided, preventing the backflow of the electric power of an electric power generation part to the commercial power source side.

The preferred embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 is a main part configuration diagram of a power generation system 1 according to an embodiment of the present invention, and FIG. 2 is a circuit example diagram of an energization control circuit employed in FIG.

As shown in FIG. 1, the power generation system 1 according to the present embodiment includes a heat supply unit 20 having a power generation unit 10 and a heat source (not shown), and these units are connected to a commercial power source.
In other words, the system 1 is configured to generate a commercial power source (single-phase three-wire) drawn from the outdoor utility pole 8 with three wires of the U-phase lead-in wire 5, the V-phase lead-in wire 6 and the ground lead-in wire 7 via the distribution board 70. 10 and the heat supply unit 20.

  And while supplying electric power to the electric equipment 2 with the electric power generation part 10 and a commercial power supply, the heat generated by the heat source (not shown) of the waste heat generated by power generation and the heat supply part 20 to the heat supply part 20 This is a system that supplies power to a connected heat utilization terminal (not shown).

The power generation unit 10 includes a power generation control circuit 11, a gas engine 12, a generator 13, an AC / DC conversion circuit 14, a DC / AC conversion circuit 15, and a voltage detection unit 16.
The gas engine 12 is a prime mover that uses city gas (natural gas) as fuel, and the generator 13 is driven by the gas engine 12 to generate AC power.

The AC / DC conversion circuit 14 is a power conversion circuit that once converts AC power generated by the generator 13 into DC power.
The DC / AC conversion circuit 15 reconverts the previously converted DC power into AC power that matches the commercial power source, and controls the output voltage, its phase, and output current in accordance with the input control signal. It is possible.

  The voltage detection unit 16 has a function of detecting the voltage of the commercial power source drawn from the outside for each of the U and V phases and transmitting it to the power generation control circuit 11. In the present embodiment, an insulation transformer is used for the voltage detection unit 16, and voltage detection is performed while insulating the internal circuit of the system 1 from the commercial power source.

  The power generation control circuit 11 is a digital processing circuit including a CPU (central processing unit), and has a function of performing control processing according to a program stored in a ROM (not shown). That is, the power generation control circuit 11 digitally processes the detection voltage of the voltage detection unit 16 and the voltage signal and current signal output from the DC / AC conversion circuit 15 to perform feedback control of the DC / AC conversion circuit 15. I do.

  As a result, the DC / AC conversion circuit 15 makes the output current constant-current controlled to a predetermined rated current value (in this embodiment, set to 5A for each phase) while matching the voltage and its phase with the commercial power supply. It is configured to output. The power generation control circuit 11 is configured to be able to transmit and receive data to and from the surplus power control unit 30 described later.

The heat supply unit 20 includes a surplus power control unit 30 having a main surplus power consumption unit 50 and a sub surplus power consumption unit 60.
The heat supply unit 20 is specifically a hot water supply device having a heat source, and the configuration relating to the heat source and the hot water supply is omitted in FIG. 1.

  The surplus power control unit 30 includes a main surplus power consumption unit 50 in addition to the surplus power control circuit 31, the energization control circuit 32, the power measurement unit 33, the voltage detection unit 34, and the power supply circuit 35.

  The power measurement unit 33 includes a U-phase power measurement circuit 33a and a V-phase power measurement circuit 33b. Each of the power measurement circuits 33 a and 33 b is connected to current detection units (current transformers) 71 and 71 of the distribution board 70 via the wiring 36. Moreover, the output of the voltage detection part 34 connected to the commercial power supply is connected to each electric power measurement circuit 33a, 33b. In the present embodiment, an insulating transformer is used for the voltage detection unit 34, and voltage detection is performed while the power measurement unit 33 is insulated from the commercial power source.

The power measuring unit 33 outputs the power consumption for each of the U and V phases by arithmetically processing the instantaneous value of the detected voltage of the voltage detecting unit 34 and the instantaneous value of the detected current of the current transformer 71 including its polarity. Has the function of
Here, if the power consumption output from the power measuring unit 33 is a positive value, it is a non-reverse flow state in which power is supplied from the commercial power source to the system 1, and if the power consumption is a negative value, the system 1 This is a backflow state in which power flows back to the commercial power supply side. Therefore, by referring to the power consumption value output from the power measuring unit 33, the power is supplied from the commercial power source to the system 1 side, or the system 1 supplies the power to the commercial power source side. It is possible to determine whether it is in a backflow state.
From this, the power measuring unit 33 has a function of a sensor that detects the presence or absence of a backflow of power to the commercial power supply side in addition to a function of outputting power consumption.

  In the present embodiment, the power measurement circuits 33a and 33b use an integrated circuit for power calculation with a built-in A / D conversion circuit, and a detection voltage obtained by sampling and digital conversion at a predetermined period (approximately 3.3 KHz) and Power is calculated based on the detected current, and an average value of power obtained over one cycle of the commercial power supply is output as power consumption. That is, the power measuring unit 33 instantaneously calculates and outputs the average power during one cycle (20 ms or 16.7 ms) of the commercial power source for each of the U and V phases. In this embodiment, in addition to the power value, the current value detected by the current transformer 71 is also output at the same time.

The surplus power control circuit 31 is a digital processing circuit including a CPU (Central Processing Unit) and has a function of performing control processing according to a program stored in a ROM (not shown). In other words, the surplus power control circuit 31 outputs a control signal to the energization control circuit 32 in accordance with the power consumption value and the current value output from the power measuring unit 33, and the main surplus power consumption unit 50 and the sub surplus power consumption. The intermittent control of the unit 60 is performed.
The surplus power control circuit 31 can transmit and receive data to and from the power generation control circuit 11 described above.

The energization control circuit 32 insulates the surplus power control circuit 31 that operates at a DC voltage from the commercial power supply, and in accordance with a control signal output from the surplus power control circuit 31, the main surplus power consumption unit 50 and the sub surplus power consumption. This is an interface circuit for intermittently connecting the unit 60.
In the present embodiment, the energization control circuit 32 is configured using a relay R as shown in FIG. In other words, the low-voltage control signal output from the surplus power control circuit 31 is applied to the transistor Q, and the drive coil of the relay R connected to the DC power source higher than the surplus power control circuit 31 is interrupted. Each load of the main surplus power consumption unit 50 and the sub surplus power consumption unit 60 connected to the energization contact is intermittently interrupted. Further, the surplus power control circuit 31 and the commercial power source are insulated by the relay R.

  In this embodiment, the energization control circuit 32 using the relay R is adopted. However, as shown in FIG. 2B, an insulating semiconductor relay (SSR) such as a phototriac PT can be used. It is. According to this configuration, the load can be intermittently connected as compared with the relay R, and the size is small, the driving current is low, and the durability is high.

  The power supply circuit 35 outputs the DC voltage required by each part of the surplus power control circuit 31, the energization control circuit 32, and the power measurement unit 33, and generates a DC voltage using either a U-phase or V-phase commercial power supply. is doing. In the present embodiment, a constant voltage power source that can ensure a specified output voltage even when the commercial power source has a significant voltage drop is employed.

  The main surplus power consumption unit 50 is a load that consumes power supplied from the power generation unit 10 or a commercial power supply, and heaters (loads) 51 and 53 and energization contacts 52 and 54 that are intermittently connected by the energization control circuit 32 are connected in series. Connected to U and V phases.

  In the present embodiment, the heater 51a and the energizing contact 52a, the heater 51b and the energizing contact 52b, and the heater 51c and the energizing contact 52c that are connected in series are connected in parallel to the U-phase side. Similarly, on the V-phase side, heaters 53a and energizing contacts 54a, heaters 53b and energizing contacts 54b, and heaters 53c and energizing contacts 54c, which are connected in series, are connected in parallel.

  Similar to the main surplus power consumption unit 50, the sub surplus power consumption unit 60 is a load that consumes power supplied from the power generation unit 10 or the commercial power source, and is intermittently connected by the heaters (loads) 61 and 63 and the energization control circuit 32. Connected to the U and V phases are connected in series with the current-carrying contacts 62, 64 connected in series, and those connected in series with the current-carrying contacts 66, 68 interrupted by the pumps 65, 67 and the current-carrying control circuit 32. The

In this embodiment, the freeze prevention heater which the heat supply part 20 has is selected as the heaters 61 and 63, and the circulation provided in one heating device of the heat utilization terminal which the heat supply part 20 similarly has as the pumps 65 and 67. A pump is selected.
In other words, the main surplus power consuming unit 50 is a dedicated load for consuming surplus power, whereas the sub surplus power consuming unit 60 is not a dedicated load, but a freezing prevention heater included in the heat supply unit 20. 61, 63 and pumps 65, 67 are used.

Next, details of control performed in the power generation system 1 of the present embodiment having such a configuration will be described.
In the following description, in order to facilitate understanding, the output currents of the U and V phases of the power generation unit 10 are assumed to be the rated current (5 A). In addition, the heaters 51a and 53a of the main surplus power consumption unit 50 are each loaded at 100W at the rated voltage (100V), the heaters 51b and 53b are loaded at 200W, and the heaters 51c and 53c are loaded at 300W, respectively. Furthermore, the heaters 61 and 63 of the auxiliary surplus power consumption unit 60 are each loaded with 200 W at the rated voltage (100 V), and the pumps 65 and 67 are each loaded with 80 W.

  In the present embodiment, as the current transformer 71 disposed on the distribution board 70, a current transformer having a ring core that is detachable from the existing wiring is adopted, and the existing U and V phase lead-in wires 5 and 6 are connected. The current is detected by electromagnetic coupling without changing. For this reason, depending on the mounting direction of the current transformer 71 and the connection of the wiring 36, there is a possibility that the power value measured by the power measuring unit 33 may be reversed. In order to avoid such a problem, when the system 1 is laid, a test operation is performed to supply power to the electrical equipment 2 with the power generation unit 10 stopped, and the power value output by the power measurement circuits 33a and 33b at this time Is stored in the surplus power control circuit 31 as conversion data, and the code conversion based on the conversion data is performed when referring to the subsequent power value.

(First embodiment)
FIG. 3 is a flowchart showing the control of the first embodiment of the present invention implemented in the power generation system 1 of FIG. 1, and FIG. 4 is an explanatory diagram showing changes in the total current consumption by the control of FIG. 3 when the commercial power supply voltage drops. is there.
In the present embodiment, since the same control is independently performed for each of the U phase and the V phase, the control of the U phase will be described in the following description.

  While the system 1 is in operation, the surplus power control circuit 31 always refers to the voltage of the commercial power transmitted via the power generation control circuit 11 (see step 200 in FIG. 3).

As a result of the reference, when the voltage of the commercial power supply is equal to or higher than the threshold value E0 (set to 90 V in the present embodiment), the process proceeds to step 212 through step 211. The surplus power control circuit 31 refers to the power consumption of the commercial power source output from the power measuring unit 33. When the power consumption is a negative value (<0), the power consumption becomes a positive value (0 or more). The connection of the load (51a-51c) of the main surplus power consumption part 50 is increased. When the power consumption becomes a positive value, connection adjustment of the loads (51a to 51c) of the main surplus power consumption unit 50 is performed. (See steps 200, 201, 2111 and 215 in FIG. 3).
However, step 211 is a process of releasing the connection when the sub surplus power consumption unit 60 is connected before the present time.

This state is a state in which the voltage drop of the commercial power supply is small. Even if the power consumption of the electrical equipment 2 is zero and the voltage is 90 V as shown in FIG. A current of 5.4 A can be consumed. Therefore, the sub surplus power consumption unit 60 is not connected, and only the load (51a to 51c) of the main surplus power consumption unit 50 is connected, and a current exceeding the output current (5A) of the power generation unit 10 is obtained. It is consumed to prevent backflow of power.
In step 215, the current consumption is adjusted in units of 100W from 0 to 600W by switching the load (51a to 51c) of the main surplus power consumption unit 50 while referring to the output power value of the power measurement unit 33. While the power consumption of the main surplus power consumption unit 50 is minimized, the backflow of power to the commercial power source is prevented.

On the other hand, when the voltage is less than the threshold value E0 and the threshold value E1 (set to 70V in the present embodiment) in steps 201 and 202, the process proceeds to step 208, and the surplus power control circuit 31 sets all the main surplus power consumption units 50. The load is connected and the freeze prevention heater 61 of the auxiliary surplus power consumption unit 60 is forcibly connected (see steps 201, 202, and 208 to 210 in FIG. 3).
However, step 209 is a process of releasing the connection when the pump of the sub surplus power consumption unit 60 is connected before the present time.

  This state is a state where the voltage drops to 70V or more and less than 90V. Therefore, as shown in FIG. 4B, if the power consumption of the electrical device 2 is zero and the voltage is 70V, the maximum current consumption of the main surplus power consumption unit 50 is reduced to 4.2 A. Unless the power consumption of 2 increases, the output current (5 A) of the power generation unit 10 cannot be consumed. For this reason, by forcibly connecting a 200 W antifreeze heater 61 capable of consuming 1.4 A at 70 V, a total current of 5.6 A is consumed to prevent backflow of power to the commercial power supply. ing.

  Furthermore, when the voltage is less than the threshold value E1 and the threshold value E2 (set to 60V in the present embodiment) in steps 202 and 203, the process proceeds to step 205, where the surplus power control circuit 31 sets all the main surplus power consumption units 50. In addition to connecting the load, all the loads (freezing prevention heater 61 and pump 65) of the auxiliary surplus power consumption unit 60 are forcibly connected (see steps 202, 203, 205 to 207 in FIG. 3 above).

  This state is a state where the voltage drops to 60V or more and less than 70V. Therefore, as shown in FIG. 4C, if the electric power consumption of the electrical device 2 is zero and the voltage is 60 V, the maximum current consumption of the main surplus power consumption unit 50 is reduced to 3.6 A and the antifreezing heater 61 is used. The current consumption of the power generation unit 10 cannot be consumed unless the power consumption of the electric device 2 is reduced to 1.2 A and the power consumption of the electrical device 2 is increased. For this reason, by connecting a pump 65 that can consume a current of about 0.5 A at 60 V, a total current of about 5.3 A is consumed to prevent the backflow of power to the commercial power source.

  On the other hand, when the voltage is less than the threshold value E2 in step 203, the surplus power control circuit 31 performs disconnection control for outputting the disconnection signal to the power generation control circuit 11 to stop the power generation of the power generation unit 10, and also performs notification control. Perform necessary control.

  Thus, according to the control of the present embodiment, in addition to the main surplus power consumption unit 50, even if the commercial power supply causes a voltage drop, the current exceeding the output current of the power generation unit 10 is always consumed. Intermittent control of the sub surplus power consumption unit 60 is performed. Thereby, it becomes possible to completely prevent the backflow of electric power to the commercial power source side due to the voltage drop of the commercial power source.

By the way, in this embodiment, control which connects the sub surplus power consumption part 60 is performed, if the voltage drop of a commercial power source arises irrespective of the power consumption condition of the electric equipment 2. FIG. For this reason, even if no backflow of power occurs due to the power consumption of the electrical equipment 2, if the commercial power supply has a voltage drop, the auxiliary surplus power consumption unit 60 is forcibly connected, and power is consumed wastefully. Will be.
Below, the control which prevents the backflow of the electric power to the commercial power source side, reducing useless electric power consumption is demonstrated.

(Second Embodiment)
FIG. 5 is a flowchart showing the control of the second embodiment of the present invention implemented in the power generation system 1 of FIG. 1, and FIGS. 6 and 7 show the change in the total current consumption by the control of FIG. 5 when the commercial power supply voltage drops. It is explanatory drawing.
5 includes the same steps (200 to 204, 211 to 215) as in FIG. 3, and therefore, the same steps are denoted by the same step numbers and redundant description is omitted.

  The surplus power control circuit 31 refers to the voltage of the commercial power source transmitted through the power generation control circuit 11, and in steps 201 and 202, determines that the commercial power source voltage is equal to or higher than the threshold E1 (70V) and lower than the threshold E0 (90V). If so, go to Step 224. Then, the surplus power control circuit 31 refers to the control signal output to the energization control circuit 32 and measures the connection load value already connected by the main surplus power consumption unit 50. When the measured connection load value is less than the load threshold W (set to 400 W in the present embodiment), the connection of the load (51a to 51c) of the main surplus power consumption unit 50 without connecting the sub surplus power consumption unit 60 (See steps 201, 202, 224, 225, and 228 in FIG. 5).

  This state corresponds to a state in which the commercial power supply drops to 70 V when the electric device 2 and the main surplus power consumption unit 50 are each loaded with 300 W, as shown in FIG. Unless the current increases, the output current (5A) of the power generation unit 10 cannot be consumed as it is. However, since the connected load value of the main surplus power consuming unit 50 is less than 400 W and an unconnected load remains, increasing the load (increasing to 500 W) consumes a total current of 5.6 A, causing the commercial power supply side to Is preventing the reverse flow of power to the.

However, in step 225, when the connection load value is equal to or greater than the load threshold W (400 W), the freeze prevention heater 61 of the auxiliary surplus power consumption unit 60 is forcibly connected, and the load (51a) of the main surplus power consumption unit 50 is connected. To 51c) (see steps 225 to 228 in FIG. 5).
However, step 226 is a process of releasing the connection when the pump 65 of the auxiliary surplus power consumption unit 60 is connected before the present time.

  This state corresponds to a state in which the commercial power supply has dropped to 70 V when the electric device 2 is 100 W load and the main surplus power consumption unit 50 is 500 W load, as shown in FIG. Since the connection load value of 50 is 400 W or more, even if all the remaining unconnected loads are connected, the output current of the power generation unit 10 cannot be consumed. Therefore, the antifreezing heater 61 that consumes 1.4 A at 70 V is forcibly connected, and the load of the main surplus power consumption unit 50 is adjusted (reduced to 500 W) to consume a total current of 5.6 A. The power consumption of the commercial power supply is reduced while preventing the backflow of power to the power supply side.

  On the other hand, when the voltage is less than the threshold value E1 (70V) and the threshold value E2 (set to 60V in this embodiment) in steps 202 and 203, the process proceeds to step 220. Then, when the connection load value of the main surplus power consumption unit 50 is less than the load threshold W (400 W), the surplus power control circuit 31 does not connect the sub surplus power consumption unit 60 and does not connect the main surplus power consumption unit 50. The connection of the loads (51a to 51c) is adjusted (see steps 202, 203, 220, 221, and 228 in FIG. 5).

  This state corresponds to a state in which the commercial power supply drops to 60 V when the electric device 2 and the main surplus power consumption unit 50 are each loaded with 300 W, as shown in FIG. Unless the current increases, the output current (5A) of the power generation unit 10 cannot be consumed as it is. However, since the connection load value of the main surplus power consumption unit 50 is less than the load threshold W (400 W), a total of 5.4 A of current is consumed by increasing the remaining unconnected load (increasing to 600 W). This prevents backflow of power to the commercial power source.

  However, in step 221, when the connection load value is equal to or greater than the load threshold W (400 W), the antifreeze heater 61 and the pump 65 of the auxiliary surplus power consumption unit 60 are forcibly connected and the main surplus power consumption unit 50 The connection of the loads (51a to 51c) is adjusted (see steps 221 to 223 and 228 in FIG. 5).

  This state corresponds to a state in which the commercial power supply drops to 60 V when the power consumption of the electrical device 2 is zero and the main surplus power consumption unit 50 is a load of 600 W, as shown in FIG. Unless the power consumption of 2 increases, the output current (5 A) of the power generation unit 10 may not be consumed as it is. Therefore, by connecting a pump 65 that consumes a current of approximately 0.5 A at 60 V in addition to the anti-freezing heater 61 of the auxiliary surplus power consumption unit 60, a total current of 5.3 A is consumed to supply the commercial power source. Prevents backflow of power.

  As described above, according to the control of the present embodiment, even when the commercial power supply has a voltage drop, when the power consumption of the electric equipment 2 as shown in FIGS. The power consumption is increased by increasing the connection load value of the main surplus power consumption unit 50 without connecting the surplus power consumption unit 60. As a result, it is possible to reduce wasteful power consumption while preventing backflow of power to the commercial power supply side.

(Third embodiment)
Next, a description will be given of control in which wasteful power consumption is further reduced while preventing the backflow of power to the commercial power supply side.
FIG. 8 is a flowchart showing the control of the third embodiment of the present invention implemented in the system 1 of FIG. 1, and FIGS. 9 and 10 are diagrams showing the change in the total consumption current by the control of FIG. 8 when the commercial power supply voltage drops. FIG.
Since FIG. 9 includes the same steps (200 to 204, 211 to 215) as FIG. 3, the same steps are denoted by the same step numbers and redundant description is omitted.

  The surplus power control circuit 31 refers to the voltage of the commercial power transmitted through the power generation control circuit 11. As a result of the reference, when it is determined in steps 201 and 202 that the voltage of the commercial power source is less than the threshold value E0 (90V) and greater than or equal to the threshold value E1 (70V), the process proceeds to step 245, and the surplus power control circuit 31 After connecting all 50 loads (51a to 51c), the output power of the power measuring unit 33 is referred to. When the output power is a positive value (0 or more), connection adjustment of the load of the main surplus power consumption unit 50 is performed (see steps 201, 202, 245 to 247, 250 in FIG. 8 above).

  This state corresponds to, for example, a state where the commercial power supply has dropped to 70 V when the electric device 2 has a 200 W load and the main surplus power consumption unit 50 has a 400 W load, as shown in FIG. By connecting all 50 loads, a current exceeding the output current of the power generation unit 10 is consumed, and no back flow of power occurs. Therefore, the sub surplus power consumption unit 60 is not connected, and only the load of the main surplus power consumption unit 50 is adjusted in step 250.

  However, when the power consumption of the commercial power source is negative (less than 0) in step 247, the surplus power control circuit 31 forcibly connects the freeze prevention heater 61 of the sub surplus power consumption unit 60 and then the main surplus power consumption unit. The connection adjustment of 50 loads is performed (see steps 247 to 250 in FIG. 8).

  This state corresponds to a state in which the commercial power supply has dropped to 70 V when the electric device 2 is 100 W load and the main surplus power consumption unit 50 is 500 W load, as shown in FIG. Even when 50 full loads are connected, the output current of the power generation unit 10 cannot be consumed. Therefore, the anti-freezing heater 61 is forcibly connected, and the load of the main surplus power consumption unit 50 is adjusted (reduced to 500 W), thereby consuming a total current of 5.6 A and preventing the reverse flow of power to the commercial power supply side. However, wasteful power consumption is reduced.

  On the other hand, when it is determined in steps 202 and 203 that the voltage of the commercial power source is less than the threshold value E1 (70V) and greater than or equal to the threshold value E2 (60V), the process proceeds to step 240, and the surplus power control circuit 31 includes the main surplus power consumption unit 50. The output power of the power measurement unit 33 is referred to with all the loads (51a to 51c) connected. When the output power is a positive value (0 or more), connection adjustment of the load of the main surplus power consumption unit 50 is performed (see steps 202, 203, 240 to 242, and 250 in FIG. 8 above).

  This state corresponds to a state in which the commercial power supply has dropped to 70 V when the electric device 2 has a 200 W load and the main surplus power consumption unit 50 has a 400 W load, as shown in FIG. By connecting all 50 loads, a current exceeding the output current of the power generation unit 10 is consumed, and no back flow of power occurs. Accordingly, the auxiliary surplus power consuming unit 60 is not connected, and the load of the main surplus power consuming unit 50 is adjusted (reduced to 500 W) in step 250 to reduce unnecessary power consumption.

  However, when the power consumption of the commercial power source is negative (less than 0) in step 242, the surplus power control circuit 31 has forcibly connected both the antifreeze heater 61 and the pump 65 of the sub surplus power consumption unit 60. The connection adjustment of the load of the main surplus power consumption unit 50 is performed (see steps 242 to 244 and 250 in FIG. 8 above).

  This state corresponds to a state in which the commercial power supply has dropped to 60 V when the power consumption of the electrical device 2 is zero and the main surplus power consumption unit 50 is a load of 600 W, as shown in FIG. Unless the power consumption of 2 increases, the output current (5 A) of the power generation unit 10 cannot be consumed as it is. Therefore, by connecting the pump 65 in addition to the antifreezing heater 61 of the auxiliary surplus power consumption unit 60, a total current of 5.3 A is consumed to prevent the backflow of power to the commercial power source side.

  As described above, according to the control of the present embodiment, even when the commercial power supply has a voltage drop, a reverse flow of power to the commercial power supply side is detected as shown in FIGS. 9B and 10B. Only when the auxiliary surplus power consumption unit 60 is connected, backflow is prevented. As a result, it is possible to reduce wasteful power consumption by the sub surplus power consumption unit 60 when no back flow of power to the commercial power source occurs.

  In the control shown in the first to third embodiments, the thresholds are set to E0, E1, E2 (90V, 70V, 60V), and the anti-freezing heater 61 and the pump 65 are provided in the auxiliary surplus power consumption unit 60. Adopted the configuration. However, the present invention is not limited to such a configuration.

  For example, it is possible to adopt a simplified configuration in which only the threshold value E0 is set and the auxiliary surplus power consumption unit 60 is only one load. It is also possible to finely control according to the voltage drop by providing the sub surplus power consumption unit 60 with a number of loads by subdividing the threshold into four or more.

  Further, the control shown in the second embodiment adopts a configuration in which one load threshold W (400 W) is set. However, a plurality of load thresholds are set and the main surplus power consumption unit 50 according to the connected load value. It is also possible to perform fine control.

  By the way, control of the said 1st and 2nd embodiment is a thing which prevents the backflow of electric power by interrupting the sub surplus electric power consumption part 60 according to the voltage drop of a commercial power source. However, backflow can be prevented by reducing the generated power (output current) of the power generation unit 10 itself without providing the auxiliary surplus power consumption unit 60. Below, control of the system 1 provided with such a structure is demonstrated.

(Fourth embodiment)
FIG. 11 is a flowchart showing the control of the fourth embodiment of the present invention performed in the system 1 of FIG. 1, and FIG. 12 shows the output current and the total consumption current of the power generation unit according to the control of FIG. It is explanatory drawing which shows a change.
Since FIG. 11 includes the same steps (200 to 204, 212 to 215) as FIG. 3, the same steps are denoted by the same step numbers and redundant description is omitted.

  The power generation system 1 of the present embodiment is different from the configuration of the system 1 shown in FIG. 1 in that the auxiliary surplus power consumption unit 60 is removed and the control configuration of the power generation unit 10 is changed. Therefore, in the following description, the main surplus power consumption unit 50 is described as the surplus power consumption unit 50.

The power generation unit 10 has the same configuration as that shown in FIG. 1, but the control thereof is different.
In other words, the power generation unit 10 shown in the first and second embodiments makes the output current the predetermined rated current value I0 (5 A per phase) while matching the output voltage with the voltage of the commercial power supply and the phase thereof. It was for constant current control.

On the other hand, the power generation unit 10 according to the present embodiment controls the DC / AC conversion circuit 15 by the power generation control circuit 11 in accordance with the control signal transmitted from the surplus power control circuit 31, so that the output voltage is commercialized. A constant current control is performed by reducing the output current to a value corresponding to the voltage of the commercial power supply while matching the voltage of the power supply and its phase.
Specifically, the power generation unit 10 of the present embodiment is configured to be capable of constant current control to three stages of limited current values I1, I2, and I3 (4A, 3A, and 2A) in addition to the rated current value I0 (5A). It is said that.

  While the system 1 is in operation, the surplus power control circuit 31 always refers to the voltage of the commercial power transmitted via the power generation control circuit 11 (see step 200 in FIG. 11).

As a result of the reference, when the voltage of the commercial power supply is equal to or higher than the threshold value E0 (set to 90 V in the present embodiment), the process proceeds to step 212 through step 265. The surplus power control circuit 31 refers to the power consumption of the commercial power source output from the power measuring unit 33. When the power consumption is a negative value (<0), the power consumption becomes a positive value (0 or more). The connection of the load of the surplus power consumption unit 50 is increased. When the power consumption becomes a positive value, the load connection of the surplus power consumption unit 50 is adjusted. (See steps 200, 201, 265, 212 to 215 in FIG. 11).
However, step 265 is control for returning the output current to the rated current value I0 when the output current of the power generation unit 10 is controlled to be changed before the present time.

  This state is a state in which the voltage of the commercial power supply is low. Even if the power consumption of the electrical device 2 is zero and the voltage is 90 V as shown in FIG. A current of 4 A can be consumed. Therefore, while maintaining the output current of the power generation unit 10 at the rated current value I0 (5A), at least any one of the loads (51a to 51c) of the surplus power consumption unit 50 is connected, and the electric power flows backward to the commercial power source side. To prevent.

  On the other hand, if it is determined in steps 201 and 202 that the voltage is less than the threshold value E0 (90V) and greater than or equal to the threshold value E1 (set to 80V in this embodiment), the process proceeds to step 264. The surplus power control circuit 31 transmits a control signal to the power generation control circuit 11, performs constant current control of the output current of the power generation unit 10 to the limit current value I1 (set to 4A in the present embodiment), and surplus power consumption. The connection adjustment of the load of the unit 50 is performed (see steps 201, 202, 264, and 263 in FIG. 11).

  This state is a state where the voltage is 80 V or more and less than 90 V. If the power consumption of the electrical device 2 is zero and the voltage is 80 V as shown in FIG. 12B, the maximum current consumption of the surplus power consumption unit 50 However, the current of the output current (5A) of the power generation unit 10 cannot be consumed unless the power consumption of the electric device 2 increases to 4.8A. For this reason, the output current of the power generation unit 10 is reduced to the limit current value I1 (4A) to prevent the backflow of power to the commercial power source.

  Furthermore, when the voltage is less than the threshold value E1 (80 V) and the threshold value E2 (set to 60 V in this embodiment) in steps 202 and 203, the process proceeds to step 262. Then, the surplus power control circuit 31 performs constant current control on the output current of the power generation unit 10 to the limit current value I2 (set to 3A in the present embodiment), and performs connection adjustment of the load of the surplus power consumption unit 50 (as described above). FIG. 8, Steps 202, 203, 262, and 263).

  This state is a state where the voltage is 60 V or more and less than 80 V. If the power consumption of the electrical device 2 is zero and the voltage is 60 V as shown in FIG. 12C, the maximum current consumption of the surplus power consumption unit 50 Decreases to 3.6A, and the rated current value I0 cannot consume the limit current value I1 (4A) from the beginning. For this reason, the output current of the power generation unit 10 is reduced to the limit current value I2 (3A) to prevent the backflow of power to the commercial power supply side.

  Furthermore, when the voltage is less than the threshold value E2 (60V) and the threshold value E3 (set to 50V in this embodiment) in steps 203 and 260, the process proceeds to step 261. Then, the surplus power control circuit 31 performs constant current control of the output current of the power generation unit 10 to the limit current value I3 (set to 2A in the present embodiment) and performs connection adjustment of the load of the surplus power consumption unit 50 (as described above). FIG. 8, Steps 203, 260, 261, and 263).

  This state is a state where the voltage is 50 V or more and less than 60 V. If the power consumption of the electrical device 2 is zero and the voltage is 50 V as shown in FIG. 12 region D, the maximum current consumption of the surplus power consumption unit 50 Decreases to 3A and coincides with the limit current value I2 (3A), and there is no power consumption margin. For this reason, the output current of the power generation unit 10 is further reduced to the limit current value I2 (3A) to prevent the backflow of power to the commercial power supply side.

  Thus, according to the control of the present embodiment, even if the commercial power supply has a voltage drop, the current that can be consumed by the surplus power consumption unit 50 always exceeds the output power (current) of the power generation unit 10. The output current of the power generation unit 10 is changed. Thereby, it becomes possible to completely prevent the backflow of electric power to the commercial power source side due to the voltage drop of the commercial power source.

  In the control of the present embodiment, the output current of the power generation unit 10 is controlled with reference to only the voltage of the commercial power supply. However, as shown in the second embodiment, the connection load value of the surplus power consumption unit 50 is set. Accordingly, it is possible to adopt a configuration in which the output current of the power generation unit 10 is controlled. According to this configuration, the output current of the power generation unit 10 can be maintained at a high value in accordance with the usage state of the electric device 2, and the power consumption of the commercial power supply can be reduced while preventing the backflow of power. is there.

  By the way, in the present embodiment, control is performed to reduce the output current of the power generation unit 10 when a voltage drop of the commercial power source occurs regardless of the power consumption state of the electric device 2. For this reason, even when the backflow of the electric power to the commercial power source does not occur due to the power consumption of the electric equipment 2, the output current of the power generation unit 10 is reduced with the voltage drop, and the power consumption of the commercial power source increases. I hate to do it. Below, the control which reduced the power consumption of commercial power supply by maintaining the output current of the electric power generation part 10 at a high value is demonstrated.

(Fifth embodiment)
FIG. 13 is a flowchart showing the control of the fifth embodiment of the present invention implemented in the system of FIG. 1, and FIGS. 14 to 16 are the output current and the total consumption current of the power generation unit under the control of FIG. It is explanatory drawing which shows the change of.
The control of this embodiment is performed by the same configuration as the system 1 described in the fourth embodiment. 13 includes the same steps (200 to 204, 260, 265, 212 to 215) as in FIG. 11, and thus the same steps are denoted by the same step numbers and redundant description is omitted.

  The surplus power control circuit 31 refers to the voltage of the commercial power transmitted through the power generation control circuit 11, and in steps 201 and 202, determines whether the voltage of the commercial power is less than the threshold E0 (90V) or more than the threshold E1 (80V). If yes, go to Step 280. And after connecting all the loads of the surplus power consumption part 50, the output electric power of the electric power measurement part 33 is referred, When positive value (0 or more), the output current of the electric power generation part 10 is controlled to the rated current value I0, Connection adjustment of the load of the surplus power consumption unit 50 is performed (see steps 201, 202, 280-282, 284, 285 in FIG. 13).

  This state corresponds to, for example, a state where the commercial power supply has dropped to 80 V when the electric device 2 has a 100 W load and the surplus power consumption unit 50 has a 500 W load, as shown in FIG. By connecting all the loads, a current exceeding the output current of the power generation unit 10 is consumed, and no back flow of power occurs. Therefore, the output current of the power generation unit 10 is maintained at the rated current I0, and the load connection of the surplus power consumption unit 50 is adjusted in step 285 to reduce wasteful power consumption.

  However, when the output power of the power measuring unit 33 is negative in step 282, the connection adjustment of the load of the surplus power consumption unit 50 is performed after the output current of the power generation unit 10 is reduced to the limit current value I1 (4A). (Refer to steps 282, 283, and 285 in FIG. 13).

  This state corresponds to a state in which the commercial power supply has dropped to 80 V when the load of the electric device 2 is zero and the surplus power consumption unit 50 is a 600 W load, as shown in FIG. 14B, for example. There is a backflow of power. For this reason, the output current of the power generation unit 10 is reduced to the limit current value I1 (4A) that can be consumed by the surplus power consumption unit 50, thereby preventing the backflow of power.

  On the other hand, when it is determined in steps 202 and 203 that the voltage of the commercial power source is less than the threshold E1 (80V) and greater than or equal to the threshold E2 (60V), the process proceeds to step 275. And after connecting all the loads of the surplus power consumption part 50, the output electric power of the electric power measurement part 33 is referred, When positive value (0 or more), the output current of the electric power generation part 10 is controlled to the rated current value I0, The connection adjustment of the load of the surplus power consumption unit 50 is performed (see steps 202, 203, 275 to 277, 279, and 285 in FIG. 13).

  This state corresponds to, for example, a state where the commercial power supply has dropped to 60 V when the electric device 2 is at 300 W load and the surplus power consumption unit 50 is at 300 W load, as shown in FIG. By connecting all the loads, a current exceeding the output current of the power generation unit 10 is consumed, and no back flow of power occurs. Therefore, the output current of the power generation unit 10 is maintained at the rated current value I0, and in step 285, only the load connection of the surplus power consumption unit 50 is adjusted to reduce wasteful power consumption.

  However, when the output power of the power measuring unit 33 is negative in step 277, the load connection adjustment of the surplus power consumption unit 50 is performed after the output current of the power generation unit 10 is reduced to the limit current value I2 (3A). This is done (see steps 277, 278, and 285 in FIG. 13).

  This state corresponds to a state in which the commercial power supply has dropped to 60 V when the load of the electric device 2 is zero and the surplus power consumption unit 50 is a 600 W load, as shown in FIG. There is a backflow of power. For this reason, the output current of the power generation unit 10 is reduced to the limit current value I2 (3A) that can be consumed by the surplus power consumption unit 50, thereby preventing the backflow of power.

  Further, when it is determined in steps 203 and 260 that the voltage of the commercial power source is less than the threshold value E2 (60V) and greater than or equal to the threshold value E3 (50V), the process proceeds to step 270. And after connecting all the loads of the surplus power consumption part 50, the output electric power of the electric power measurement part 33 is referred, When positive value (0 or more), the output current of the electric power generation part 10 is controlled to the rated current value I0, The connection adjustment of the load of the surplus power consumption unit 50 is performed (see steps 203, 260, 270 to 272, 274, and 285 in FIG. 13).

  This state corresponds to a state in which the commercial power supply has dropped to 50 V when the load of the electric device 2 is 500 W and the surplus power consumption unit 50 is 100 W load, as shown in FIG. 16A, for example, and the surplus power consumption unit 50 By connecting all the loads, a current exceeding the output current of the power generation unit 10 is consumed, and no back flow of power occurs. Therefore, the output current of the power generation unit 10 is maintained at the rated current value I0, and in step 285, only the load connection of the surplus power consumption unit 50 is adjusted to reduce wasteful power consumption.

  However, when the output power of the power measurement unit 33 is negative in step 272, the load connection adjustment of the surplus power consumption unit 50 is performed after the output current of the power generation unit 10 is reduced to the limit current value I3 (2A). This is done (see steps 272, 273, and 285 in FIG. 10).

  This state corresponds to a state in which the commercial power supply drops to 50 V when the load on the electric device 2 is zero and the surplus power consumption unit 50 is a 600 W load as shown in FIG. There is a backflow of power. For this reason, the output current of the power generation unit 10 is reduced to the limit current value I3 (2A) that can be consumed by the surplus power consumption unit 50, thereby preventing the backflow of power.

  As described above, according to the control of the present embodiment, even when the commercial power supply has a voltage drop, as shown in FIGS. 14 (b), 15 (b), and 16 (b), the power supply to the commercial power supply side is reduced. Only when the backflow of electric power is detected, the output current of the power generation unit 10 is reduced. Thereby, when the backflow of the electric power to the commercial power source side has not arisen, the power supply amount of the power generation unit 10 can be maintained at a high value, and the power consumption of the commercial power source can be reduced.

  In the control shown in the fourth and fifth embodiments, the threshold value is set to E0 to E3, and the output current value of the power generation unit 10 is set to the rated current value I0 and the limit current values I1 to I3. The present invention is not limited to such a configuration.

  For example, it is possible to adopt a simplified configuration in which only the threshold value E0 is set and only one limited current value lower than the rated current value I0 is set. Further, by further subdividing and setting the threshold value and the limit current value, it is possible to perform fine control according to the voltage drop of the commercial power supply.

  As mentioned above, although control of 1st-5th embodiment of this invention was demonstrated, in the said structure, the heat | fever which the load (51a-51c, 53a-53c) of the main surplus power consumption part (surplus power consumption part) 50 generate | occur | produces. We did not take a configuration to recover and reuse energy.

  However, for example, a configuration in which heat energy generated by the power consumption of the main surplus power consumption unit (surplus power consumption unit) 50 is transmitted to the exhaust heat recovery system of the gas engine 12 or the heat energy is directly supplied to the heat. The structure which transmits to the thermal system path of the part 20 can be taken. By adopting such a configuration, the thermal energy generated by the main surplus power consumption unit (surplus power consumption unit) 50 can be returned to the heat supply unit 20 without being wasted, and the total energy efficiency of the system 1 is improved. It becomes possible to make it.

  Moreover, in the said embodiment, although the electric power generation part 10 which drives the generator 13 with the gas engine 12 was employ | adopted, it can replace with the gas engine 12 and a gas turbine, a diesel engine, etc. can also be used. It is also possible to employ the power generation unit 10 using a fuel cell.

It is a principal part block diagram of the electric power generation system which concerns on embodiment of this invention. It is a circuit example figure of the electricity supply control circuit employ | adopted in FIG. It is a flowchart which shows the control of 1st Embodiment of this invention implemented in the system of FIG. It is explanatory drawing which shows the change of the total consumption current by control of FIG. 3 at the time of the voltage drop of a commercial power source. It is a flowchart which shows control of 2nd Embodiment of this invention implemented in the system of FIG. (A), (b) is explanatory drawing which shows the change of the total consumption current by control of FIG. 5 at the time of the voltage drop of a commercial power source. (A), (b) is explanatory drawing which shows the change of the total consumption current by control of FIG. 5 in the case of the voltage drop of another range of a commercial power source. It is a flowchart which shows the control of 3rd Embodiment of this invention implemented in the system of FIG. (A), (b) is explanatory drawing which shows the change of the total consumption current by control of FIG. 8 at the time of the voltage drop of a commercial power source. (A), (b) is explanatory drawing which shows the change of the total consumption current by control of FIG. 8 in the case of the voltage drop of another range of a commercial power source. It is a flowchart which shows the control of 4th Embodiment of this invention implemented in the system of FIG. It is explanatory drawing which shows the change of the output current of a power generation part by the control of FIG. 11, and the total consumption current at the time of the voltage drop of a commercial power source. It is a flowchart which shows the control of 5th Embodiment of this invention implemented in the system of FIG. (A), (b) is explanatory drawing which shows the change of the output current of a power generation part by the control of FIG. 13, and the total consumption current at the time of the voltage drop of a commercial power source. (A), (b) is explanatory drawing which shows the change of the output current of the electric power generation part by the control of FIG. 13, and the total consumption current at the time of the voltage drop of another range of a commercial power source. (A), (b) is explanatory drawing which shows the change of the output current of the electric power generation part by the control of FIG. 13, and the total consumption current at the time of the voltage drop of another range of a commercial power source.

Explanation of symbols

1 Power generation system 2 Electrical equipment 5 Commercial power supply (U-phase lead-in wire)
6 Commercial power supply (V-phase lead-in wire)
7 Commercial power supply (ground lead-in wire)
DESCRIPTION OF SYMBOLS 10 Power generation part 16 Voltage detection part 20 Heat supply part 33 Electric power measurement part 50 Main surplus power consumption part 60 Sub surplus power consumption part 61, 63, 65, 67 Load (Load of sub surplus power consumption part)

Claims (8)

A power generation unit that includes a power generation unit and a heat supply unit having a heat source, and supplies the generated power of the power generation unit to an electrical device, and supplies exhaust heat generated by power generation and heat generated by the heat supply unit to a heat utilization terminal In the system,
A voltage detection unit that detects a voltage of a commercial power source that is drawn from outside, a main surplus power consumption unit that can consume power exceeding the output power of the power generation unit when the commercial power source has a rated voltage value, and the main surplus power A sub-surplus power consumption unit that assists the power consumption of the consumption unit,
The power generation unit is configured to perform constant current power generation that is connected to the commercial power source and controls an output current to a predetermined rated current value while matching an output voltage and a phase thereof with the commercial power source.
When the voltage detected by the commercial power supply by the voltage detection unit drops below a preset threshold, the sub surplus power consumption unit is forcibly connected as a load in addition to the main surplus power consumption unit. Power generation system.   When the connection load value of the main surplus power consumption unit is greater than or equal to a preset load threshold value and the detected voltage of the commercial power source by the voltage detection unit falls below the threshold value, the main surplus power consumption unit In addition, the power generation system according to claim 1, wherein the auxiliary surplus power consumption unit is forcibly connected as a load.   A power measuring unit that measures the power consumption of the commercial power source, the commercial power source detection voltage by the voltage detection unit drops below the threshold, and the full load of the main surplus power consumption unit is connected 2. The power generation according to claim 1, wherein when the measurement value of the power measurement unit becomes a negative value, the sub surplus power consumption unit is forcibly connected as a load in addition to the main surplus power consumption unit. system.   The auxiliary surplus power consumption unit is configured to include a plurality of loads that can be intermittently connected, and is at least one of a connected load value of the main surplus power consumption unit or a voltage value of a commercial power source detected by the voltage detection unit. The power generation system according to any one of claims 1 to 3, wherein a plurality of loads are connected in a stepwise manner according to the value of. A power generation unit that includes a power generation unit and a heat supply unit having a heat source, and supplies the generated power of the power generation unit to an electrical device, and supplies exhaust heat generated by power generation and heat generated by the heat supply unit to a heat utilization terminal In the system,
A voltage detection unit for detecting the voltage of a commercial power source drawn from the outside, and a surplus power consumption unit capable of consuming power exceeding the output power of the power generation unit when the commercial power source has a rated voltage value;
The power generation unit is configured to be connected to the commercial power source and to control an output current with a predetermined rated current value as an upper limit while matching an output voltage and a phase thereof with the commercial power source,
When the detected voltage of the commercial power source by the voltage detection unit falls below a preset threshold, the output current of the power generation unit is forcibly reduced from a rated current value to a predetermined limit current value. Power generation system.   A power measurement unit that measures power consumption of the commercial power supply, the commercial power detection voltage detected by the voltage detection unit decreases below the threshold, and the full load of the surplus power consumption unit is connected 6. The power generation system according to claim 5, wherein when the measured value of the power measurement unit becomes a negative value, the output current of the power generation unit is forcibly reduced from the rated current value to the limit current value. .   The power generation unit is configured to be able to control the output current continuously or stepwise, and adjusts and controls the output current continuously or stepwise according to the voltage value of the commercial power source detected by the voltage detection unit. The power generation system according to claim 5 or 6, wherein   The power generation according to any one of claims 1 to 7, wherein heat energy generated by power consumption of the main surplus power consumption unit or the surplus power consumption unit can be returned to the heat supply unit. system.

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