JPH09117062A - Power generation control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power generation control system in which the operation is sustained by controlling a low throw-in switch to prevent deterioration and stoppage of a power generator. SOLUTION: A power generation control system comprising a power generator and an electric supply system wherein the electric supply system is provided with a power generator output monitoring means 13 for delivering output signals corresponding to the output power, output voltage and output current from the power generator to the electric supply system, and load power monitoring means 30-12 for delivering an output signal corresponding to the load power. A comparator 9 receives output signals from the power generator output monitoring means 13 and the load power monitoring means 10-12 and delivers a control output signal for opening or closing load throw-in switches 2-4, when the output voltage or output current from the power generator deviates from a preset level, to the load throw-in switches 2-4.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention generates power by a power generator and supplies the power generated by the power generator to a plurality of or a single load via a load closing switch individually provided for a load of an electric power supply system. The present invention relates to a power generation control system that controls deterioration of a power generation device and stops the power generation device by controlling a load closing switch to continue operation.

Further, according to the present invention, the fuel supply amount or the fuel supply pressure is detected by the fuel supply monitoring means, and the fuel is supplied from the fuel supply system which receives the output signal from the fuel supply monitoring means and switches the fuel by the fuel switching device. Receiving power generation by the power generator and supplying the generated power of the power generator to a plurality of or a single load via the load injection switch, by controlling the load injection switch, fuel supply at the time of fuel switching The present invention relates to a power generation control system that prevents the power generation device from stopping due to a decrease in the output voltage of the power generation device due to a delay or the like, and continues the operation of the power generation device even when fuel is switched.

[0003]

2. Description of the Related Art The configuration of a conventional power generation control system is shown in FIG. In the power generation control system in FIG. 2, power is generated by the power generator 1, and the generated power 8 of the power generator 1 is supplied to the loads 5, 6, and 7 via the load closing switches 2, 3, and 4. The loads 5 to 7 connected here are loads supplied via a power conversion device such as a converter. A power conversion device such as a converter is a device that operates to increase the input current and secure the necessary power when the input voltage drops in order to supply the power required by the load. It can be said to be an electric load.

FIG. 6 shows the characteristics of the generator output voltage-output current when the generator 1 is a fuel cell. It can be seen that the output voltage decreases as the output current increases. Here, an example in which the power generation capacity of the power generation device 1 is lowered due to some trouble will be described. P, V and I shown in FIG. 6 are the output power, the output voltage and the output current at the rated output of the fuel cell, respectively. As the power generation capacity decreases, the voltage-current characteristics deteriorate and the output voltage changes from V to V '.
The output current increases from I to I ′ in order to secure the electric power P required by the load. When the fuel cell continues to operate in a state where the output current is higher than the output current I at the rated output, the cell stack deteriorates. When the output of the power generator reaches the limit voltage Vb or the limit current Ib, the power generator 1 stops. The limit voltage Vb and the limit current Ib differ depending on the fuel cell, but as an example, the limit voltage Vb is 85% of the output voltage during rated output operation.
The limit current Ib is set to a value of about 150% of the output current during the rated output operation, and the limit current Ib is operated.

An example of the operation in such a conventional power generation control system is shown in FIG. In FIG. 5, the power generator 1
When the power is generated in step S3 and the power supply to the loads 5 to 7 is started, the load is input according to the following procedure. That is, the power generation device 1
In the unloaded state, the output voltage is V3. Here, assuming that the load application sequence is load 5, load 6, and load 7, when the load application switch 2 is turned on at time t0 and power is supplied to the load 5, the output power becomes W3, and power is generated. The device output voltage and current are V4 and I3, respectively. Next, when the load closing switch 3 is turned on at time t1 to supply power to the load 6, the output power becomes W2, and the generator output voltage and current become V5 and 14, respectively. Further time t2
When the load closing switch 4 is turned on, the output power becomes W1, and the generator output voltage and current become V1 and I1, respectively. In FIG. 5, the power generator 1 generates power, the load input switches 2 to 4 are turned on, and the power is supplied to the loads 5 to 6. Due to a malfunction of the power generator, the power generator output voltage is changed from V1 to V1. When the load decreases to V2 and the load is a constant power load, the generator output current increases from I1 to I2. Since the power output of the generator is constant, the output voltage of the generator further decreases to the limit voltage Vb, or when the limit current Ib is reached, the generator stops.

When the power generator is stopped due to the above-mentioned factors, it is necessary to restart the power generator.
Power cannot be supplied to 6,7. The start-up time of the power generator 1 varies depending on the type of power generator, but in the case of a fuel cell, for example, it takes several hours or more to start. During this time, power cannot be supplied to the load for a long time. Further, when the power generation device is a fuel cell, there is a problem that the operation is continued in the state where the output current is increased, or the battery is deteriorated by the start / stop operation and the battery life is shortened.

FIG. 8 shows the configuration of another conventional power generation control system. 8, in the conventional power generation control system, city gas or the like is input to the fuel supply system 25 as the regular fuel 21, and liquefied propane gas or the like is input as the auxiliary fuel 22,
Normally, the common fuel 21 is supplied to the power generation device 26 to generate power, and the generated power 27 is supplied to the loads 31 to 33 via the load injection switches 28 to 30.
Here, the connected loads 31 to 33 are loads including a power conversion device such as a converter. It can be said that a power converter such as a converter is a constant power load for a power generator because it operates so as to increase the input current and secure necessary power when the input voltage decreases.

When it is detected by the fuel supply monitoring means 24 that the supply of the regular fuel 21 is hindered and the fuel supply amount or the supply pressure falls below a preset value,
A fuel switching signal A is sent from the fuel supply monitoring means 24 to the fuel switching device 23, and the fuel switching device 23 transfers the fuel to the regular fuel 2
The fuel is switched from 1 to the backup fuel 22 and supplied to the power generator 26. In this case, in order to prevent the output voltage from decreasing due to the decrease in the fuel supply amount or the fuel supply pressure to fall below the limit voltage Vb and the power generation device 26 from stopping, the fuel supply amount or the fuel supply pressure is set in advance. If it is less than the value, the comparison operator 37 loads the load switch 28-
By outputting control output signals F to H to 30 to open or close the loads 31 to 33, it is aimed to continue the operation without stopping the fuel cell even when the fuel is switched. Here, in the comparison calculator 37, the capacities of the loads 31 to 33 are set to be constant at preset electric power, and calculation is performed on the assumption that the capacities do not change with the passage of time or operating conditions.

An example of the operation in such a conventional power generation control system is shown in FIGS. 11 and 12. In FIG. 11, when the supply of the common fuel 21 is disturbed at time t0, the power generation capacity of the power generation device 26 decreases due to the decrease in the fuel supply amount or the fuel supply pressure, and the output voltage decreases to V2 at time t1. At time t1, the fuel supply monitoring means 24 detects that the fuel supply amount or the fuel supply pressure has dropped to P2, sends the fuel switching signal A to the fuel switching device 23, and the fuel switching device 23 performs fuel switching. Here, the output power is W1
Is constant. The fuel switching is started when the fuel supply amount or the fuel supply pressure decreases to P2, but the fuel required for power generation of a constant output power W1 due to the response delay of the backup fuel supply system and the fuel control valve. The fuel supply that compensates for the shortage of the supply amount or fuel supply pressure cannot be secured, and the output voltage continues to decrease. Therefore, at time t2, when the fuel supply amount or the fuel supply pressure is reduced to the preset P3, the comparison computing unit 37 performs the comparison computation based on the power capacity preset for each load, and is obtained from the computation result. The load capacity is controlled by sending the control signal output to the load closing switch and opening the load closing switch. Here, if the load control order is the load 33, 32, 31 as a result of the calculation based on the preset load capacity, the time t
At 2, the control output signal F is sent from the comparison calculator 37 to the load closing switch 30 and the load closing switch 30 is opened to reduce the output power to W2. However, when the capacity of the load 33 controlled by the load closing switch 30 has changed from the initial setting and the ratio of the load 33 to the total load amount has decreased, the output by opening the load 33 is output. The voltage drop cannot be prevented. As a result, when the limit voltage Vb is reached at time t3, the power generation device 26 stops.

Further, as shown in FIG. 12, if the supply of the regular fuel 21 is disturbed at time t0, the time t1
In the case where the fuel supply monitoring means 24 detects that the fuel supply amount or the fuel supply pressure has decreased to P2, the fuel switching signal A is sent to the fuel switching device 23, and the fuel switching device 23 performs the fuel switching. When the fuel supply amount or the fuel supply pressure becomes P3 and P4 at time t2 and t3 as the fuel supply amount or the fuel supply pressure decreases, the control output signals F and G are sent to load the switch. When the fuel cells are switched by opening the valves 30 and 29 to prevent the output voltage from decreasing and the fuel is switched to the preset value at the time t5 when the fuel supply amount or the fuel supply pressure reaches the preset P4, the preset value is set. Then, the control output signal G is sent out according to the result calculated based on the load capacity, and the load applying switch 29 is turned on to supply the electric power to the load 32. If the ratio of the load to the total load has increased since the setting, the load 32 is turned on to decrease the output voltage and reach the limit voltage Vb at time t6. Will stop.

As described above, when the load capacity changes from a preset value, the load capacity is not properly controlled, and as a result, the power generation device 26 needs to be restarted,
During this time, the power generator 26 cannot supply power to the loads 31 to 33. The start-up time of the power generator 26 differs depending on the type of power generator, but in the case of a fuel cell, for example, it takes several hours or more to start. During this time, there has been a problem that power cannot be supplied to the load for a long time.

Further, depending on the type of fuel, the power generator 26
When the output capacity of the fuel cell changes, for example, when the power generation device 26 is a fuel cell, city gas is used as the regular fuel 21 and the backup fuel 22 is used.
When liquefied propane gas is used as the fuel gas, the difference in gas composition between city gas and liquefied propane gas causes a difference in the ability of the fuel processor to add hydrogen to the fuel to obtain hydrogen necessary for power generation. The output capacity of the fuel cell may change. The difference in the output capacity depends on the gas composition and the capacity of the fuel processor. For example, the output capacity may be 10 when the common fuel 21 is used as the fuel and may be reduced to 8 when the auxiliary fuel 22 is used as the fuel. When the fuel is switched and power is generated by the power generation device 26, if the output power of the power generation device 26 is kept constant, the fuel supply amount or fuel supply pressure cannot be secured, and the output voltage drops and the power generation device 26 stops. Therefore, there is a problem that the fuel cannot be switched and the operation of the power generator cannot be continued. Further, when the power generator is a fuel cell, there is a problem that the life of the fuel cell is shortened due to deterioration of the cell due to start / stop operations.

[0013]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and the power generation capacity of the power generator is lowered due to a malfunction of the power generator and the output voltage of the power generator is lowered or the output current is increased. A power generation control system that solves the problem that the power generation device stops as a result, and the problem that when the power generation device is a fuel cell, the fuel cell is deteriorated by continuing the operation with the output current increased, The purpose is to provide.

Further, according to the present invention, when the fuel supply amount or the fuel supply pressure is reduced and the fuel is switched, the load of the preset load capacity is controlled with respect to the reduction of the fuel supply amount or the fuel supply pressure. In a power generation control system that prevents a stop due to a decrease in output voltage due to a decrease in fuel supply amount or fuel supply pressure, the capacity of a preset load changes and load control is not performed properly When the output voltage drops and as a result the generator stops, and when the output capacity of the generator changes depending on the fuel type, the output capacity decreases, and as a result,
An object of the present invention is to provide a power generation control system that solves the problem that the output voltage drops and the power generator stops.

[0015]

In order to achieve the above object, the present invention provides a power generation control system comprising a power generator and an electric power supply system, wherein the electric power supply system has a power generator output power, an output voltage and an output current. And a load power monitoring means for sending an output signal corresponding to the load power, and an output signal of the power generation device output monitoring means and the load power monitoring means. In response to this, when a power generator output voltage or output current deviates from a preset value, a comparison arithmetic unit is provided for sending a control output signal for opening or closing the load closing switch to the load closing switch. It is what

The present invention comprises a fuel supply system, a power generator, and an electric supply system, and the fuel supply monitoring means provided in the fuel supply system makes the fuel supply amount or fuel supply pressure equal to or lower than a preset value. That is detected, a fuel switching signal is sent to the fuel switching device to perform fuel switching, fuel is supplied to the power generation device, power is generated by the power generation device, and power is generated by the power supply system through the load injection switch. In a power generation control system for supplying electric power to a load, fuel supply monitoring means for sending an output signal corresponding to a fuel supply amount or a fuel supply pressure for each fuel type, and electric power for each load supplied via the load closing switch. Is provided with a load power monitoring means for transmitting an output signal corresponding to the fuel supply monitoring means and the load power monitoring means, and receives the output signals from the fuel supply monitoring means and the load power monitoring means, In which characterized in that a comparison operation unit for outputting a switching signal to the load application switches to be less than the output power set in advance for each pressure.

Further, the power generator is a fuel cell power generator. According to the above, the present invention receives the output signals corresponding to the generator output power, the output voltage, the output current, and the load power from the generator output monitoring means and the load power monitoring means provided in the electricity supply system, and switches the load closing switch. The most main feature is that a comparison calculator for sending a control output signal for opening or closing is sent to the load closing switch. Further, a means for limiting the hunting operation of the load closing switch is provided.

The conventional technique is that, when the output voltage or output current of the power generator deviates from a preset value, the comparator outputs a control output signal to the load closing switch and opens the load closing switch, or It prevents the output voltage of the power generator from dropping or the output current increasing to prevent the power generator from deteriorating or stopping.
The difference is that continuous power generation by the power generator is possible.

Further, according to the present invention, the output signal corresponding to the fuel supply amount or the fuel supply pressure for each fuel type is output from the fuel supply monitoring means provided in the fuel supply system, and the load power is supplied from the load power monitoring means provided in the electricity supply system. When an output signal corresponding to the above is constantly sent to the comparison arithmetic unit, the comparison arithmetic unit performs the comparison arithmetic operation, and it is detected that the fuel supply amount or the fuel supply pressure is lower than a preset value for each fuel type. It is characterized in that a comparison calculator for sending a control output signal for opening or closing a part or all of the load closing switch to the load closing switch is provided. Also, when the fuel switching is completed and the fuel supply amount or fuel supply pressure is restored,
A control output signal from the comparison calculator is sent to the load closing switch to turn on the load closing switch to supply power to the load.

The conventional technique is to always release an appropriate load even if the load capacity changes from a preset load capacity when it is detected that the fuel supply amount or the fuel supply pressure has dropped when switching fuel. In order to do so, load power monitoring means for constantly monitoring the load power is provided, and the load to be controlled is selected by selecting the load to be controlled in accordance with the fuel type, the fuel supply amount, or the fuel supply pressure by the comparison calculator. Even when the capacity changes, appropriate load control is performed,
A point to prevent the power generator from stopping due to a decrease in the output voltage of the power generator, and when the fuel supply amount or fuel supply pressure is restored after the fuel switching is completed, the fuel switching is completed and the predetermined fuel supply amount or fuel supply pressure is reached. After confirming that the load capacity of the control target changes by sending the control output signal from the comparison calculator to the load closing switch and turning on the load closing switch to restart the power supply to the load. In this case, by preventing the power generator from stopping due to the output voltage drop of the power generator, the fuel is switched in the fuel supply system, and the power generator can continuously generate power to supply power to the load. different. Further, even when the output capacity of the power generator changes depending on the fuel type, a comparison calculation is performed using the output signals from the fuel supply monitoring means and the load power monitoring means, and the fuel type and the fuel supply amount or the fuel supply pressure are compared. The difference is that by opening and closing the load closing switch, the output power is controlled to prevent the power generator from stopping, and the power generator continuously generates power to supply power to the load.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below in detail with reference to the drawings. An embodiment of the present invention will be described with reference to FIG. 1, in the present invention, the power generator output power, the output voltage and the output current detection signal A are sent from the power generator output monitor means 13 to the load power generator monitor means 1, 1.
Load power detection signals B, C, and D are sent from 1 and 12 to the comparison calculator 9. The comparison operation unit 9 performs comparison operation, and the load operation switches 2 to 2 are connected from the comparison operation unit 9 according to the operation result.
4 outputs switch opening / closing signals E, F, G to selectively open / close the load closing switches 2-4 to control the output power of the power generator 1.

Next, an example of the operation of the power generation control system of the present invention will be described with reference to FIG. The generator output power (load power), output voltage, and output current shown in FIG. 3 are examples.
In addition, in the figure, an example in which the output power (load power) is operated at the rated output of the power generator is described.

The signal A, which is constantly transmitted from the generator output monitoring means 13 and the load power monitoring means 10, 11, and 12,
B, C, and D are constantly calculated by the comparison calculator 9, and the power generator 1
If the output voltage drops from V1 due to the power generation capability of the power generation device 1 due to such a problem as described above, and the output voltage or output current deviates from the preset V2 or I2, the load switch 2 Open / close signals E to G on 4
To release some or all of the loads 5 to 7. If the order of load selection and cutoff is load 5, 6 and 7,
When the output voltage decreases to V2 or the output current increases to I2 at time t1, the control output signal E is sent from the comparison calculator 9 to the load closing switch 4 and the load closing switch 4 is activated.
The output electric power becomes W2 by opening the circuit, and the output voltage and the output current are restored to V3 and I3, respectively. Here, when the output voltage further decreases and becomes V2 or I2 again at time t2, the comparison output unit 9 sends the control output signal F to the load closing switch 3 to open the load closing switch 3 so that the output power is W3. And the output voltage and output current are restored to V3 and I4, respectively. As described above, when the output voltage or the output current value set in advance is deviated by a certain deviation from the limit voltage Vb and the limit current Ib of the power generator, the load closing switches 2 to 4 are selectively opened. It is possible to prevent the power generation device from being deteriorated or stopped, and to continue the operation of the power generation device.

Next, the operation will be described when the malfunction of the power generator is resolved, the output voltage and the output current of the power generator satisfy the preset values, and the power generator is restored to the normal operating state. By opening the load input switches 3 and 4, the power generation capacity follows the output power of W3,
The output voltage and output current converge at V6 and I6, respectively.
If the malfunction of the power generator 1 is eliminated at time t3 ', the power generation capacity is restored, and the power generator output voltage rises to V4 at time t4. It is confirmed at the time t5 that the generator output voltage and the output current have satisfied the preset values, and the comparison calculator 9 confirms that the control output signal F is set to the load input switch 3.
Then, the load input switch 3 is turned on to supply the load 6 with electric power, the generator output power becomes W2, and the output voltage and output current change to V5 and I5, respectively. Further, when the control output signal E is sent to the load closing switch 4 at time t6 and the load closing switch 4 is closed to supply power to the load 7, the generator output power becomes W1, and the output voltage and the output current are V1 respectively. , I1 is restored to normal operating conditions.

Next, the prevention of the hunting operation of the load closing switches 2 to 4 will be described. If the generator output voltage or output current deviates from the preset value and the load closing switches 2 to 4 are opened, the generator malfunction is resolved and the output voltage and output current satisfy the preset values again. Control is performed to turn on the load closing switches 2 to 4, but due to the capacity of the load to be released, the generator output voltage and output current satisfy the preset values immediately after the load closing switch is opened, and the load closing switch 2 is turned on again. There is a possibility of causing so-called hunting in which ~ 4 is input. In order to avoid this, the control output signal E from the comparison calculator 9
When the load closing switches 2 to 4 are turned on by G, the number of times the load is turned on is counted, and the load closing switches 2 to 4 are controlled so as not to be automatically turned on more than a preset number of times. Hunting of the switch can be prevented. FIG. 4 shows an example of preventing the hunting of the load closing switch. The output voltage rises or the output current increases due to a malfunction of the power generator, etc.
When it becomes V2 or I2 at, the comparison output unit 9 sends the control output signal E to the load closing switch 4 to open the load closing switch 4. The output power is W2. Here, when the output voltage or current recovers to the preset V3 or I3, for example, when the capacity of the opened load is large,
The control output signal E is again sent from the comparison calculator 9 to the load closing switch 4 and the load closing switch 4 is closed. However, when the load is turned on, the output voltage or current becomes V
Since it deviates from 2 or I2, the hunting state in which the load closing switch 4 is opened again is obtained. For this reason, the number of times the closing control output signal E is sent is counted, and when the limit value is set here, after the closing control output signal E of the load closing switch 4 is sent at time t2, the load closing switch is switched on. Since the closing signal of No. 4 is not sent out, it is possible to prevent hunting that repeats closing and opening. After the load closing switch 4 is opened at the time t3, when the output voltage decreases or the output current increases and V2 or I2 is deviated again, the control output signal F is sent to the load closing switch 3 to output the load closing switch. By opening 3, the output power becomes W3, and at time t5, the output voltage and current become V5 and I5, respectively, and the power generation capability follows the output power.

In the embodiment of the present invention, the case where the total capacity of the load groups connected to the electric power supply system is less than or equal to the output capacity of the power generator 1 is described as an example. Even when the total capacity of the load groups to be generated is equal to or larger than the output capacity of the power generator 1, the power generator output monitoring means 13 and the load power monitoring means 10 can be applied by applying the present invention.
12 to 12 output signals A, B, C, D are input to the comparison calculator 9 to perform comparison calculation, and the loads 5 to 7 are selectively opened and closed to prevent deterioration or stop of the power generator. It is possible to prevent it and continue operation.

Further, in the above embodiment, the case where the power generation device is a fuel cell has been described, but any power generation control device that supplies the output of the power generation device to a load, such as an engine generator, an inverter or a converter, may be used. Needless to say, the present invention can be applied to a power generation control system using a different power converter.

Next, another embodiment of the present invention will be described with reference to FIG. Referring to FIG. 7, in the present invention, the fuel supply system 2
The common fuel 21 and the auxiliary fuel 22 are supplied to 50, and the common fuel 21 is always supplied to the power generation device 26. The power 27 generated by the power generator 26 is supplied to the loads 31 to 33 via the load closing switches 28 to 30.

Fuel supply monitoring means 24 of the fuel supply system 250
The output signal B sent from 0 corresponding to the fuel supply amount or the fuel supply pressure for each fuel type and the output signal corresponding to the electric power for each load sent from the load power monitoring means 34, 35, 36 of the electric supply system Comparator 3 receiving C, D, E
A comparison calculation is performed at 70, and the load closing switch is opened / closed so that the output power becomes equal to or less than the preset output power for each fuel type and fuel supply amount or fuel supply pressure.

Next, an example of the operation of the power generation control system of the present invention will be described with reference to FIGS. 9 and 10. 9 and 10
The fuel supply amount or fuel supply pressure, the generator output power (load power), and the output voltage shown in are examples. The fuel supply amount or fuel supply pressure differs depending on the fuel type, but is shown as a relative value in the figure.

In FIG. 9, the fuel supply monitoring means 240 indicates that the supply of the regular fuel 21 is hindered at time t0 and the fuel supply amount or fuel supply pressure is reduced to P2 at time t1.
The fuel switching signal A is sent to the fuel switching device 23, and the fuel switching device 23 switches the fuel. After the fuel switching is started at time t1, the output voltage continues to decrease until the fuel supply amount or the fuel supply pressure is sufficient for the output power W1, and then decreases to V3 at time t2.

In the comparison calculator 370, the output signal B corresponding to the fuel type and the fuel supply amount or the fuel supply pressure from the fuel supply monitoring means 240 and the load power monitoring means 34-3.
From the relationship between the fuel supply amount or fuel supply pressure and the output voltage, the output capacity C to E corresponding to the load power from 6 is input, and the output voltage does not fall below Vb and the load is the minimum load. The comparison operation is performed so as to select, and the control output signal is output according to the operation result.
It is output to 0 to control the load capacity. If the control order of the load closing switches is 33, 32, and 31 as a result of the comparison calculation by the comparison calculator 370, the time t2 is reached.
When the fuel supply amount or the fuel supply pressure decreases to P3 set in advance, the control output signal F is compared with the comparison calculator 370.
From the load input switch 30 to the load input switch 30 and the load input switch 30 is opened, the output power becomes W2 and the output voltage recovers to V4. However, since the supply amount required for the output power W2 cannot be secured, the fuel supply amount is further increased. Alternatively, since the fuel supply pressure drops, the output voltage drops to V3 again at time t3. At time t3, when the fuel supply amount or the fuel supply pressure drops to P4 set in advance, the control output signal G is sent from the comparison calculator 370 to the load closing switch 29, and the load closing switch 29 is opened. The output power becomes W3, and the output voltage recovers to V4.

Although the output voltage continues to decrease until the fuel supply amount or the fuel supply pressure reaches the value required for the output power after the fuel switching is started at the time t1, the output power is controlled to W3 at the time t3, and The decrease in the output voltage is suppressed by the increase in the fuel supply amount or the fuel supply of the reserve fuel, and the output voltage becomes V5 at time t4. After that, as the fuel supply amount or the fuel supply pressure increases, the output voltage recovers and starts increasing, and recovers to V6 at time t5. The fuel supply amount or fuel supply pressure stabilizes at P6 required for the output power W3.

When the fuel switching is completed and the fuel supply amount or the fuel supply pressure is recovered, the fuel switching is completed and the fuel supply amount or the fuel supply pressure becomes the predetermined value set for each fuel type and output capacity. When it is confirmed that the control output signal G is sent from the comparison calculator 370 to the load applying switch 29 at time t6 and the load applying switch 29 is turned on, the output power becomes W2, and at time t7, the output voltage, The fuel supply amount or fuel supply pressure is V7 and P7, respectively. Further, at time t8, the control output signal F is compared with the comparison calculator 37.
From 0 to the load input switch 30, the output power becomes W1 by turning on the load input switch 30, and at time t9, the output voltage, the fuel supply amount, or the fuel supply pressure becomes V1 and P1, respectively, and the normal operating state is achieved. .

Next, the operation when the output capacity changes depending on the fuel type will be described with reference to FIG. In FIG. 10, the case where the auxiliary fuel 22 is used has a smaller output capacity than the case where the regular fuel 21 is used. In FIG. 10, the supply of the common fuel 21 is disturbed at time t0, and the fuel supply amount or the fuel supply pressure is changed to time t1.
The fuel supply monitoring means 240 detects that the fuel supply signal has been reduced to P2, and sends the fuel switching signal A to the fuel switching device 23. The fuel switching device 23 starts fuel switching. The fuel supply monitoring means 240 detects that the fuel supply pressures have dropped to P3 and P4, respectively, and sends control output signals F and G from the comparison calculator 370 to the load closing switches 30 and 29, respectively. 9 is opened to control the output power from W1 to W2, and further to W3, thereby preventing the output voltage from decreasing due to the decrease in the fuel supply amount or the fuel supply pressure and performing the fuel switching operation.
The operation is the same as the case where the output capacity does not change depending on the fuel type shown in FIG.

At time t4, the fuel supply amount or fuel supply pressure required for the output power W3 is secured and the decrease in output voltage stops, and the output voltage recovers and rises as the fuel supply amount or fuel supply pressure increases. Turned to V6 at time t5,
Fuel supply amount or fuel supply pressure, output power V
6, stable at P6. Here, the output voltage, the fuel supply amount, or the fuel supply pressure remains lower than the case of FIG. 9 due to the change in the output capacity due to the difference in the fuel type.

When the fuel switching is completed and the fuel supply amount or the fuel supply pressure is recovered, it is confirmed that the fuel supply amount or the fuel supply pressure has reached a predetermined value set for each fuel type and output capacity. Then, at time t6, the comparison output unit 370 sends the control output signal G to the load closing switch 29,
By turning on the load turning-on switch 29, the output power becomes W2. Also, at time t7, the output voltage, the fuel supply amount, or the fuel supply pressure becomes V7 and P7, respectively, and stabilizes. Here, when the load closing switch 30 is further turned on to increase the output power to W1, the output voltage falls below the lower limit voltage Vb due to the change in the output capacity depending on the fuel type, and the power generator stops. For this reason, the output signals of the fuel supply monitoring means 240 and the load power monitoring means 34 to 36 are compared by the comparison computing unit 370, and the load input switches 28 to 30 are selectively turned on. Depending on the type, the output capacity will be limited to less than or equal to continue operation.

In the embodiment of the present invention, the case where the total capacity of the load groups connected to the fuel supply system is less than or equal to the output capacity of the power generation device 26 has been described as an example. Even in the case where the total capacity of the load groups to be used is equal to or larger than the output capacity of the power generation device 26, the fuel supply monitoring means 240 and the load power monitoring means 3 can be applied by applying the present invention.
The output signals B, C, D, and E of 4 to 36 are compared with each other by a comparison calculator 370.
To the load calculation unit 370 to perform a comparison calculation,
It is possible to prevent the power generator from stopping by selectively opening and closing the power generators 1 to 33 and to continue the operation of the power generator even when the fuel is switched.

Further, in the above-described embodiment, the case where the power generation device is a fuel cell has been described, but any power generation device having a fuel supply system may be used, for example, a power generation control system using an internal combustion engine such as an engine generator. It goes without saying that it can also be applied to.

[0040]

As described above, according to the present invention, when the power generation device is in the process of generating power and the power generation capacity is lowered due to a malfunction of the power generation device, the load closing switch is opened / closed to control the load capacity. It is possible to provide a power generation control system capable of preventing the power generation device from stopping due to a decrease in output voltage or an increase in output current of the device and continuing power generation. In particular, when the power generator is a fuel cell, by applying the present invention, it is possible to prevent the catalyst platinum particles from aggregating and dropping off of the fuel cell stack due to an increase in output current during power generation, and deterioration such as carbon corrosion. it can. Further, it is possible to prevent the deterioration of the fuel cell due to the acceleration of the fuel cell due to the continued operation in the state where the output current is increased, and the shortening of the life of the fuel cell.

Further, according to the present invention, when the load closing switch is opened and closed to control the load capacity in order to prevent the output voltage from decreasing at the time of fuel switching, the fuel type, the fuel supply amount or the fuel supply pressure and the load are always maintained. By monitoring the capacity and performing a calculation to select the load to be controlled at all times, appropriate load control can be performed even when the output capacity changes depending on the fuel type and when the load capacity changes from a preset value. Since it becomes possible, it is possible to provide a power generation control system capable of preventing a stop of the power generation device due to a decrease in output voltage because a predetermined load capacity control cannot be performed at the time of fuel switching, and continuing power generation. . In particular, when the power generation device is a fuel cell, by applying the present invention, it is possible to prevent the catalyst platinum particles in the cell stack from aggregating and falling off and deteriorating such as carbon corrosion due to the fuel cell being stopped at the time of fuel switching. It is possible to prevent the life of the fuel cell from being shortened.

[Brief description of the drawings]

FIG. 1 is a system configuration diagram showing an embodiment of the present invention.

FIG. 2 is a system configuration diagram showing an example of a conventional power generation control system.

FIG. 3 is a characteristic diagram showing an example of changes in power generator output power (load power), power generator output voltage, output current, detection signal, and control output signal in the present invention.

FIG. 4 is a characteristic diagram showing an example of changes in power generator output power (load power), power generator output voltage, output current, detection signal, and control output signal in the present invention.

FIG. 5 is a characteristic diagram showing an example of changes in generator output power (load power), generator output voltage, and output current in a conventional power generation control system.

FIG. 6 is a characteristic diagram showing an example of output voltage-current characteristics of a fuel cell.

FIG. 7 is a system configuration diagram showing another embodiment example of the present invention.

FIG. 8 is a system configuration diagram showing another example of a conventional power generation control system.

FIG. 9 is a detection signal in the power generation control system of the present invention,
It is a characteristic view which shows an example of a control output signal, a fuel supply amount or fuel supply pressure, a generator output power (load electric power), and a generator output voltage.

FIG. 10 is a characteristic diagram showing an example of detection signals, control output signals, fuel supply amount or fuel supply pressure, power generator output power (load power), and power generator output voltage in the power generation control system of the present invention.

FIG. 11 is a detection signal in a conventional power generation control system,
It is a characteristic view which shows an example of a control output signal, a fuel supply amount or fuel supply pressure, a generator output power (load electric power), and a generator output voltage.

FIG. 12 is a detection signal in a conventional power generation control system,
It is a characteristic view which shows an example of a control output signal, a fuel supply amount or fuel supply pressure, a generator output power (load electric power), and a generator output voltage.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Generator 2, 3, 4 ... Load injection switch 5, 6, 7 ... Load 8 ... Generated power 9 ... Comparison calculator 10, 11, 12 ... Load power monitor 13 ... Generator output monitor 21 ... Regular fuel 22 ... Spare fuel 23 ... Fuel switching device 24, 240 ... Fuel supply monitoring means 25, 250 ... Fuel supply system 26 ... Generator 27 ... Generated power 28, 29, 30 ... Load input switch 31, 32, 33 ... Load 34, 35, 36 ... Load power monitoring means 37, 370 ... Comparison calculator

Claims (5)

[Claims] 1. A power generating device and an electric power supply system, wherein the power generating device generates electric power and supplies the power to a plurality of or a single load via a load closing switch individually provided for the load of the electric power supply system. In the power generation control system, the electric power supply system is provided with a power generator output monitoring means for detecting a power generator output power, an output voltage and an output current, and a load power monitoring means for detecting a power supplied to each load, By receiving signals from the device output monitoring means and the load power monitoring means, and when the output of the power generator deviates from a preset value for each output power capacity, by opening or closing the load closing switch, the power generator And a comparator for sending a control output signal to the load closing switch for controlling the output of the control circuit so as not to deviate from a preset value. Power generation control system, characterized in that. 2. The power generation control system according to claim 1, wherein the load is provided to prevent a hunting operation due to a change in the output of the power generator due to a change in the output of the load closing switch caused by the control output of the comparator. A power generation control system comprising means for counting the number of times the closing switch is closed and limiting the closing of the load closing switch. 3. The power generation control system according to claim 1 or 2, wherein the power generation device is a fuel cell power generation device. 4. A fuel supply system, a power generator, and an electric supply system, wherein a fuel supply monitoring means provided in the fuel supply system detects that the fuel supply amount or the fuel supply pressure has dropped to a preset value. In this case, a fuel switching signal is sent to the fuel switching device provided in the fuel supply system to switch the fuel to supply fuel to the power generation device, generate power in the power generation device, and generate power in the electricity supply system. In a power generation control system that supplies multiple or independent loads to the load through a load switch that is individually provided for the load, sends a signal corresponding to the fuel supply amount or fuel supply pressure to the fuel supply system for each fuel type. Fuel load monitoring means and load power monitoring means for detecting power supplied to each load are provided, and the load is received in response to signals from the fuel supply monitoring means and the load power monitoring means. It is characterized in that a comparison calculator is provided to send a control output signal to the load closing switch for controlling the output power of the generator by controlling the on-switch so as to be equal to or less than the preset power for each fuel. Power generation control system. 5. The power generation control system according to claim 4, wherein the power generation device is a fuel cell power generation device.