JP5098967B2 - Fuel cell power generation system - Google Patents

Description

  The present invention relates to a fuel cell power generator system, and more particularly to switching of a power feeding path of an actuator or a control means.

  In order to start power generation, the fuel cell power generation system generates hydrogen gas, which is a fuel gas mainly composed of hydrogen, by a hydrogen generator, and reacts the generated hydrogen gas and oxidant gas in a stack. Generate electricity. At this time, it takes a relatively long time (for example, about one hour) to generate a hydrogen-rich gas sufficient to actually become a fuel gas for power generation.

  Meanwhile, the fuel cell power generation system has controls such as a valve that switches the flow path of the raw material gas, a pump that supplies cooling water, and a heater that raises the temperature of the hydrogen generator until hydrogen reforming is sufficiently performed. is necessary.

  The drive power for these valves, pumps, heaters, etc. is created by the AC / DC converter from the system power supply (commercial power supply) until the stack power generation starts, and the control circuits for various valves, pumps, and boards Power is being supplied to

  In addition, after power generation of the stack is started, necessary power is generated from the stack or a DC / DC converter from the stack, and power is supplied to various valves, pumps, substrate control circuits, and the like.

  In this way, the power generation efficiency can be improved by switching the power supply source between the system side and the stack side to various valves, pumps, circuit board control circuits and the like during power generation and during non-power generation.

At this time, as a method of switching the power supply source during power generation and non-power generation, there is a method in which the output of two voltages is connected by diode OR and power is supplied from the higher one of the voltages. It is possible to easily switch the power supply source without software or complicated control.
JP 2008-135200 A

  However, the conventional configuration has a problem that a part of the power generated by the stack is consumed (lost) by the diode, and the power generated by the stack cannot be effectively used.

  Therefore, in view of the above-described conventional problems, the present invention provides power generated by a stack in a fuel cell power generation system including power supply switching means that switches power supply to an actuator or control means to either the system power supply side or the stack side. When power is supplied to the actuator or the control means, a part of the power generated by the stack is not consumed (lost) by the power source switching means, and the power generated by the stack can be used effectively.

  In order to achieve the above object, a fuel cell power generation system according to the present invention includes a stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, and an AC voltage of a system power source set in advance. An AC / DC converter for converting to a DC voltage lower than the lowest output voltage of the stack, and a power source switching means for switching power supply to the actuator or control means to either the output side of the AC / DC converter or the output side of the stack A stack cutting means for turning on the connection between the stack and the power source switching means when the power generation of the stack starts and turning off when the power generation of the stack is stopped, and the power source switching means includes: an input on the AC / DC converter side; There is a diode between the output and the forward direction from the input to the output. Serial between the input of the stack cutting means side and the output is characterized in that there is no diode.

  As a result, there is no diode between the input and the output on the stack cutting means side in the power supply switching means. Therefore, when the power generated by the stack is used as the power supply for the actuator or the control means, the diode consumes (loss) power. Can be prevented.

  In addition, since the power source is switched from the commercial power supply (system power supply) to the stack after the stack generates power (power generation above the preset minimum output voltage), the stability of the system operation can be maintained. .

  Further, in the power supply switching means, there is a backflow prevention diode between the input on the system power supply (AC / DC converter) side and the output, in which the direction from the input to the output is the forward direction, and the AC / DC converter Converts the AC voltage of the system power source into a DC voltage lower than the minimum output voltage of the stack. Therefore, when the stack is generating power with power higher than the minimum output voltage of the stack, Even if the connection to the DC converter is not turned off (cut off), power is supplied from the stack side to the actuator or control means. Therefore, when the stack is generating power normally, power is supplied from the system power supply side to the actuator or control means. Install a component that cuts off the connection between the AC / DC converter input and the system power supply so that power is not supplied (for example, a relay). The control of the fuel cell power generation system is easy because it is not necessary to control a component (for example, a relay) that cuts off the connection between the input of the AC / DC converter and the system power supply. Thus, since the configuration is simple and the number of parts can be reduced, it is possible to realize a fuel cell power generator system that is inexpensive and has improved stable operation.

  In addition, when a component that cuts off the connection between the input of the AC / DC converter and the system power supply (for example, a relay (relay)) is omitted, the stack output voltage decreases temporarily (instantaneously) and the AC / DC converter Even if the output voltage is lower than the output voltage of the DC converter, the power supply switching means can automatically and instantaneously switch the power supply to the actuator or control means from the stack side to the system power supply side. Will improve.

  Even if there is no backflow prevention diode between the input and output on the stack cutting means side in the power supply switching means, the connection between the stack and the power supply switching means is turned on when the power generation of the stack is started and turned off when the power generation of the stack is stopped. Since there is a stack cutting means that does not generate power in the stack, it is possible to prevent inflow of power from the AC / DC converter side to the stack, and by applying a reverse voltage to the stack, Failures such as shortening the life of the stack or destroying the stack can be prevented.

  Further, when the output voltage of the AC / DC converter becomes higher than the output voltage of the stack due to abnormal operation of the AC / DC converter, the connection between the power source switching means and the stack is cut off by the stack cutting means. By doing so, it is possible to prevent the inflow of electric power to the stack, and thus it is possible to prevent the expansion of failure damage during abnormal operation of the fuel cell power generation system.

  Further, another fuel cell power generation system of the present invention includes a stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, and a minimum output of the stack in which an AC voltage of a system power supply is preset. An AC / DC converter that converts the voltage to a DC voltage lower than the voltage; power supply switching means that switches power supply to the actuator or control means to either the output side of the AC / DC converter or the output side of the stack; and the stack; The stack cutting means that turns on the connection with the power supply switching means when the power generation of the stack starts and turns off when the power generation of the stack stops, and the input and output between the stack cutting means side of the power supply switching means and the output of the stack Short-circuit means for short-circuiting when starting power generation and releasing the short-circuit when power generation is stopped in the stack The power supply switching means includes a diode whose forward direction is between the input and output on the AC / DC converter side and between the input and output on the stack cutting means side. It is characterized by being.

  In the above configuration, the power source switching means includes a diode whose forward direction is between the input and output on the AC / DC converter side and between the input and output on the stack cutting means side. Since there is a short-circuit means for short-circuiting between the input and output on the stack cutting means side in the power supply switching means by starting the power generation of the stack and releasing the short-circuit by stopping the power generation of the stack, the input on the stack cutting means side in the power supply switching means When the output and the output are short-circuited (during stack power generation), the configuration is substantially the same as in the previous invention, and the same operations and effects as in the previous invention can be obtained.

  In addition, when power is not generated in the stack, the input and output on the stack cutting means side in the power supply switching means are not short-circuited, and the input and output on the stack (stack cutting means) side in the power supply switching means are not Since the diode for preventing backflow provided in such a manner that the direction toward the output becomes the forward direction in between is effective, the connection is turned off while the stack cutting means keeps the connection between the stack and the power supply switching means. Even if there is a malfunction or failure that does not occur (for example, when the stack cutting means is a component such as a relay and the contact point of the relay is short-circuited), the AC / DC converter side to the stack Inflow of power can be prevented, and by applying a reverse voltage to the stack, the life of the stack is shortened and Click can prevent failure such or break.

  Further, when the output voltage of the AC / DC converter is in an abnormal state exceeding a predetermined voltage, the short-circuit means is configured to release the short-circuit between the input and output on the stack (stack cutting means) side in the power supply switching means. If there is a problem or failure that the stack cutting means does not turn off the connection while the connection between the stack and the power supply switching means remains ON (for example, the stack cutting means is a component such as a relay, Even if the relay contacts are short-circuited), abnormal power inflow to the stack can be prevented, improving the power generation efficiency of the fuel cell and at the time of abnormal system operation (system This can prevent the spread of damage (when one component fails).

  In the fuel cell power generation system of the present invention, when power is supplied from the stack side to the actuator or the control means, power is supplied without passing through the diode, so that the power generated by the stack is effectively used without loss by the diode. Therefore, the power generation efficiency of the fuel cell can be improved.

  In addition, since the power source is switched from the commercial power supply (system power supply) to the stack after the stack generates power (power generation above the preset minimum output voltage), the stability of the system operation can be maintained. .

  In addition, when the stack is generating power with power higher than the minimum output voltage of the stack, the power is supplied from the stack side to the actuator or control without turning off (cutting off) the connection between the system power supply and the AC / DC converter. Since the power is supplied to the means, a component that cuts off the connection between the input of the AC / DC converter and the system power supply so that the power is not supplied to the actuator or the control means from the system power supply side when the stack is normally generating power (for example, It is possible to adopt a configuration in which a relay (relay) is not provided, and it is not necessary to control a component (for example, a relay (relay)) that cuts off the connection between the input of the AC / DC converter and the system power supply. Fuel cell power generation that is inexpensive and has improved stable operation because the control of the device system is simplified, the configuration is simple, and the number of parts can be reduced. Location system can be realized.

  In addition, when a component that cuts off the connection between the input of the AC / DC converter and the system power supply (for example, a relay (relay)) is omitted, the stack output voltage decreases temporarily (instantaneously) and the AC / DC converter Even if the output voltage is lower than the output voltage of the DC converter, the power supply switching means can automatically and instantaneously switch the power supply to the actuator or control means from the stack side to the system power supply side. Will improve.

  Even if there is no backflow prevention diode between the input and output on the stack cutting means side in the power supply switching means, the connection between the stack and the power supply switching means is turned on when the power generation of the stack is started and turned off when the power generation of the stack is stopped. Since there is a stack cutting means that does not generate power in the stack, it is possible to prevent inflow of power from the AC / DC converter side to the stack, and by applying a reverse voltage to the stack, Failures such as shortening the life of the stack or destroying the stack can be prevented.

  Further, when the output voltage of the AC / DC converter becomes higher than the output voltage of the stack due to abnormal operation of the AC / DC converter, the connection between the power source switching means and the stack is cut off by the stack cutting means. By doing so, it is possible to prevent the inflow of electric power to the stack, and thus it is possible to prevent the expansion of failure damage during abnormal operation of the fuel cell power generation system.

  1st invention converts the alternating current voltage of the stack | stuck which reacts hydrogen gas and oxygen to generate electric power, an actuator or control means, and a system power supply into the DC output voltage lower than the minimum output voltage of the said preset stack | stuck An AC / DC converter; power supply switching means for switching power supply to the actuator or control means to either the output side of the AC / DC converter or the output side of the stack; and connection between the stack and the power supply switching means. A stack cutting means that is turned on when power generation of the stack is started and turned off when power generation of the stack is stopped, and the power supply switching means changes from the input to the output between the input and the output on the AC / DC converter side. There is a diode whose forward direction is the forward direction, but between the input and output of the stack cutting means side Diode and said that there is no.

  In the first invention, the power source switching means has a diode for preventing backflow between the input and output on the system power supply (AC / DC converter) side, but the input on the stack (stack cutting means) side and the output When there is no diode between them, the stack is not generating power, or the output voltage of the stack is lower than the output voltage of the AC / DC converter, so power is supplied from the system power supply side to the actuator or control means However, if the stack output voltage is higher than the output voltage of the AC / DC converter and power is supplied to the actuator or control means from the stack side, do not go through the diode. By supplying power, the stack generates power (power generation above the preset minimum output voltage), and then the power source is switched to commercial power. When switching from the stack to the stack, the stability of the system operation can be maintained, and power is supplied to the actuator or control means from the stack side while maintaining the configuration to supply power to the actuator or control means from the two power supply paths. Since the loss of the diode can be eliminated, the generated power of the stack can be used effectively, and the power generation efficiency of the fuel cell power generation system can be improved.

  In addition, since the power source is switched from the commercial power supply (system power supply) to the stack after the stack generates power (power generation above the preset minimum output voltage), the stability of the system operation can be maintained. .

  Further, in the power supply switching means, there is a backflow prevention diode between the input on the system power supply (AC / DC converter) side and the output, in which the direction from the input to the output is the forward direction, and the AC / DC converter Converts the AC voltage of the system power source into a DC voltage lower than the minimum output voltage of the stack. Therefore, when the stack is generating power with power higher than the minimum output voltage of the stack, Even if the connection with the DC converter is not turned off (cut off), power is always supplied from the stack side to the actuator or control means. Therefore, when the stack is normally generating power, the power is supplied from the system power supply side to the actuator or control means. That cuts off the connection between the input of the AC / DC converter and the system power supply so that power is not supplied to the power supply (for example, a relay) The control of the fuel cell power generation system is simple because it is not necessary to control a component (for example, a relay) that cuts off the connection between the input of the AC / DC converter and the system power supply. Thus, since the configuration is simple and the number of parts can be reduced, a fuel cell power generator system that is inexpensive and has improved stable operation can be realized.

  In addition, when a component that cuts off the connection between the input of the AC / DC converter and the system power supply (for example, a relay (relay)) is omitted, the stack output voltage decreases temporarily (instantaneously) and the AC / DC converter Even if the output voltage is lower than the output voltage of the DC converter, the power supply switching means can automatically and instantaneously switch the power supply to the actuator or control means from the stack side to the system power supply side. Will improve.

  Even if there is no backflow prevention diode between the input and output on the stack cutting means side in the power supply switching means, the connection between the stack and the power supply switching means is turned on when the power generation of the stack is started and turned off when the power generation of the stack is stopped. Since there is a stack cutting means that does not generate power in the stack, it is possible to prevent inflow of power from the AC / DC converter side to the stack, and by applying a reverse voltage to the stack, Failures such as shortening the life of the stack or destroying the stack can be prevented.

  Further, when the output voltage of the AC / DC converter becomes higher than the output voltage of the stack due to abnormal operation of the AC / DC converter, the connection between the power source switching means and the stack is cut off by the stack cutting means. By doing so, it is possible to prevent the inflow of electric power to the stack, and thus it is possible to prevent the expansion of failure damage during abnormal operation of the fuel cell power generation system.

  According to a second aspect of the present invention, a stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, and an AC voltage of a system power supply is converted to a DC voltage lower than a preset minimum output voltage of the stack. An AC / DC converter; power supply switching means for switching power supply to the actuator or control means to either the output side of the AC / DC converter or the output side of the stack; and connection between the stack and the power supply switching means. A stack cutting means that is turned on when power generation of the stack is started and turned off when power generation of the stack is stopped, and an input and an output on the stack cutting means side of the power supply switching means are short-circuited when power generation of the stack is started, and Short circuit means for canceling the short circuit by power generation stop, the power supply switching means, Characterized in that a direction toward the output both between said output and said stack means for cutting side input between the input and output of the C / DC converter side is diode forward.

  The power supply switching means in the second invention is directed to the output both between the input and output on the system power supply (AC / DC converter) side and between the input on the stack (stack cutting means) side and the output. There is a diode for preventing backflow with the direction as the forward direction. This is a so-called diode OR. Is provided, so that when the input and output on the stack cutting means side in the power supply switching means are short-circuited (during stack power generation), substantially the same as in the first aspect of the present invention. It becomes a structure and the effect | action and effect similar to 1st this invention can be acquired.

  In addition, when power is not generated in the stack, the input and output on the stack cutting means side in the power supply switching means are not short-circuited, and the input and output on the stack (stack cutting means) side in the power supply switching means are not Since the diode for preventing backflow provided in such a manner that the direction toward the output becomes the forward direction in between is effective, the connection is turned off while the stack cutting means keeps the connection between the stack and the power supply switching means. Even if there is a malfunction or failure that does not occur (for example, when the stack cutting means is a component such as a relay and the contact point of the relay is short-circuited), the AC / DC converter side to the stack Inflow of power can be prevented, and by applying a reverse voltage to the stack, the life of the stack is shortened and Click can prevent failure such or break.

  Further, when the output voltage of the AC / DC converter is in an abnormal state exceeding a predetermined voltage, the short-circuit means is configured to release the short-circuit between the input and output on the stack (stack cutting means) side in the power supply switching means. If there is a problem or failure that the stack cutting means does not turn off the connection while the connection between the stack and the power supply switching means remains ON (for example, the stack cutting means is a component such as a relay, Even if the relay contacts are short-circuited), abnormal power inflow to the stack can be prevented, improving the power generation efficiency of the fuel cell and at the time of abnormal system operation (system This can prevent the spread of damage (when one component fails).

  According to a third aspect of the present invention, in the second aspect of the invention, the power supply switching is performed when the output of the AC / DC converter exceeds a predetermined voltage that is higher than normal and lower than the minimum output voltage of the stack during power generation of the stack. The short circuit between the input and output on the stack cutting means side of the means is released.

  Thereby, for example, an AC / DC output voltage measuring means for measuring the output voltage of the AC / DC converter is provided and connected to the short-circuit means, and the AC measured by the AC / DC output voltage measuring means during power generation of the stack. When the output voltage of the DC / DC converter is equal to or lower than the predetermined voltage (normally), the short-circuit means is short-circuited between the input and output on the stack cutting means side in the power supply switching means, the stack is generating power, and When the output voltage of the AC / DC converter measured by the AC / DC output voltage measuring means is higher than normal and exceeds a predetermined voltage below the minimum output voltage of the stack (an abnormality occurs), the short-circuit means turns the power supply switching means. By canceling (breaking) the short circuit between the input and output on the stack cutting means side, the short-circuit means can be automatically opened and closed appropriately, and AC / DC When the output voltage of the inverter is normal and below the specified voltage and the output voltage of the stack is higher than the output voltage of the AC / DC converter, the stack cutting means connects the stack and the power supply switching means. The power can be supplied to the actuator or the control means. In this case, since the short-circuit means is in a short-circuit state, the loss of the diode can be eliminated, and the output voltage of the AC / DC converter becomes a predetermined voltage during power generation of the stack. If an abnormality exceeding the above occurs, the short-circuit means releases (cuts off) the short-circuit, and there is a problem or failure that the stack cutting means does not turn off the connection while the connection between the stack and the power supply switching means remains on ( For example, if the stack cutting means is a part such as a relay and the relay contact part has a short circuit failure ), It is possible to prevent the inflow of abnormal power to the stack.

  Further, when the output voltage of the AC / DC converter returns from the voltage exceeding the predetermined voltage to the predetermined voltage or less, if the predetermined condition is satisfied (for example, an abnormality in which the output voltage of the AC / DC converter exceeds the predetermined voltage is temporarily Immediately, when the output voltage of the AC / DC converter returns below the predetermined voltage, or when the output voltage of the AC / DC converter exceeds the predetermined voltage, but the voltage value exceeding it is relatively small) If the short-circuit means is configured to again short-circuit between the input and output on the stack cutting means side, the power is supplied to the actuator or control means from the stack side by returning the short-circuit means to the original short-circuit state. The loss of the diode can be eliminated.

  According to a fourth invention, in any one of the first to third inventions, the stack cutting means generates a predetermined voltage that is higher than the normal output voltage of the AC / DC converter and lower than the minimum output voltage of the stack during power generation of the stack. The connection between the stack and the power supply switching means is turned off when the voltage exceeds the threshold.

  Thereby, for example, an AC / DC output voltage measuring means for measuring the output voltage of the AC / DC converter is provided and connected to the stack cutting means, and the stack is generating power and is measured by the AC / DC output voltage measuring means. When the output voltage of the AC / DC converter is equal to or lower than a predetermined voltage (normal time), the stack cutting means connects the stack and the power supply switching means, and the stack is generating power and the AC / DC output voltage measuring means. When the measured output voltage of the AC / DC converter is higher than normal and exceeds the predetermined voltage below the minimum output voltage of the stack (abnormality occurs), the stack cutting means connects the stack and the power supply switching means. By shutting off (OFF), the stack cutting means can be appropriately automatically opened and closed, and the output voltage of the AC / DC converter is a predetermined voltage. When the output voltage of the stack is higher than the output voltage of the AC / DC converter at the normal time below, the stack cutting means connects the stack and the power supply switching means, so power is supplied to the actuator or control means from the stack side. When power is being supplied from the stack side to the actuator or control means, if an abnormality occurs and the output voltage of the AC / DC converter exceeds the specified voltage, the stack cutting means switches between the stack and the power supply. Even when the output voltage of the AC / DC converter becomes higher than the output voltage of the stack by disconnecting (OFF) the connection with the means, it is possible to prevent the abnormal power from flowing into the stack, and the fuel cell power generator It is possible to prevent an increase in damage caused by malfunction of the system.

  Further, when the output voltage of the AC / DC converter returns from the voltage exceeding the predetermined voltage to the predetermined voltage or less, if the predetermined condition is satisfied (for example, an abnormality in which the output voltage of the AC / DC converter exceeds the predetermined voltage is temporarily Immediately, when the output voltage of the AC / DC converter returns below the predetermined voltage, or when the output voltage of the AC / DC converter exceeds the predetermined voltage, but the voltage value exceeding it is relatively small) In addition, if the stack cutting means is configured to reconnect the stack and the power supply switching means, power can be supplied again to the actuator or the control means from the stack side.

  According to a fifth aspect of the present invention, there is provided a stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, an AC / DC converter for converting an AC voltage of a system power supply into a DC voltage, and the actuator or control means. Power supply switching means for switching the power supply to either the output side of the AC / DC converter or the output side of the stack, and the connection between the system power supply and the AC / DC converter is turned on before the stack starts power generation. And a system disconnection unit that turns off when the stack starts generating power above the minimum output voltage; an AC / DC output voltage measurement unit that measures the output voltage of the AC / DC converter and detects the state of the system disconnection unit; The AC / DC output voltmeter indicates that the system disconnection means is turned off in connection between the stack and the power supply switching means. The stack cutting means that is turned on when the means detects and the AC / DC output voltage measuring means detects that the system disconnecting means is turned on, and the input and output on the stack cutting means side in the power supply switching means When the AC / DC output voltage measuring means detects that the system disconnecting means is turned off, the AC / DC output voltage measuring means detects that the system disconnecting means is turned on. The power supply switching means is directed to the output both between the input and output on the AC / DC converter side and between the input and output on the stack cutting means side. There is a diode having a forward direction.

  In the above configuration, when the system disconnection means is turned on before the stack starts power generation, the AC / DC converter converts the AC voltage of the system power supply into a DC voltage, and the output of the AC / DC converter passes through the power supply switching means. The actuator or control means receives power from the output side of the AC / DC converter via the power supply switching means. At this time, when the AC / DC output voltage measuring means detects that the system disconnecting means is turned on based on the output voltage of the AC / DC converter, the stack cutting means turns off the connection between the stack and the power supply switching means. Since the short-circuit means does not short-circuit between the input and output on the stack cutting means side in the power supply switching means, it is possible to prevent inflow of power from the AC / DC converter side to the stack. Thus, it is possible to prevent a failure such as a reduction in the lifetime of the stack or a destruction of the stack by applying a reverse voltage to the stack.

  At this time, even if there is a malfunction or failure in the short-circuit means and the short-circuit state, if the stack cutting means turns off the connection between the stack and the power supply switching means, the power from the AC / DC converter side to the stack Inversely, even if the stack cutting means has a problem or failure and the connection between the tack and the power supply switching means is in the ON state, the short-circuit means is on the stack cutting means side in the power supply switching means. Since the diode between the input and output on the stack cutting means side in the power supply switching means prevents backflow to the stack side unless the input and output are short-circuited, the AC / DC converter side to the stack Inflow of electric power from can be prevented.

  When the stack starts to generate power above the minimum output voltage, the system disconnection unit turns off the connection between the system power supply and the AC / DC converter. When the input of the AC / DC converter is disconnected by turning off the system disconnection means, the output of the AC / DC converter is turned off. Based on the output voltage of the AC / DC converter, the AC / DC converter is turned off. When the output voltage measuring means detects, the stack cutting means turns on the connection between the stack and the power supply switching means, and the short circuit means short-circuits between the input and output on the stack cutting means side in the power supply switching means. Is sent to the actuator or the control means via the short-circuit means instead of going through the power supply switching means (diode).

  Thus, when power is supplied to the actuator or control means from the stack side, the loss of the diode can be eliminated, so that the generated power of the stack can be used effectively, and the power generation efficiency of the fuel cell power generation system Can be improved.

  When power is supplied to the actuator or control means from the stack side, the system disconnection means turns off the connection between the system power supply and the AC / DC converter. Inflow of power can be prevented.

  According to a sixth invention, in any one of the first to fifth inventions, the output voltage from the stack or the AC / DC converter is changed to a predetermined voltage between the power source switching means and the actuator or control means, and the actuator or control is performed. A DC / DC converter for supplying power to the means is provided.

  As a result, there is a problem that the voltage on the output side of the power supply switching means is different between when power is supplied to the actuator or control means from the output side of the stack and when power is supplied from the output side of the AC / DC converter. Or, when power is supplied from the output side of the stack and the output power of the stack fluctuates, or when power is supplied from the output side of the AC / DC converter, the output voltage of the AC / DC converter Can be solved by the DC / DC converter, and the actuator or the control means can be supplied with a stable voltage.

  Hereinafter, embodiments of a fuel cell power generation system according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
FIG. 1 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 1 of the present invention.

  As shown in FIG. 1, the fuel cell power generation system according to the present embodiment includes a stack 3 that generates power by reacting hydrogen gas and oxygen, and an actuator (such as a valve or a heater that switches the flow path of gas or water). (Or control means) 5, AC / DC converter 1 for converting the AC voltage of system power supply (commercial power supply) 6 to a DC voltage lower than the preset minimum output voltage of stack 3, and power supply to actuator or control means 5 Is switched to either the output side of the AC / DC converter 1 or the output side of the stack 3, and the connection between the stack 3 and the power supply switching means 4a is turned on when the power generation of the stack 3 is started, and the power generation of the stack 3 is stopped. The stack cutting means 2 is turned off by

  The power supply switching means 4a has a diode between the input and the output on the AC / DC converter 1 side in the forward direction from the input to the output, but between the input and the output on the stack cutting means 2 side. It has a configuration without a diode.

  Next, the operation of the fuel cell power generator system of the present embodiment will be described.

  Here, for the sake of explanation, it is assumed that the minimum output voltage of the stack 3 is 15V, and the setting of the output voltage of the AC / DC converter 1 is 12V.

  The fuel cell power generator system is used when the user performs a power-on operation and when the user frequently uses the fuel cell power generator system due to the learning mode of the fuel cell power generator system. Start to start.

  In a state where the stack 3 of the fuel cell power generation system is not generating power, the drive power source of the actuator or the control means 5 such as a valve and a pump in the fuel cell power generation system is an AC / DC converter. 1 is converted into a DC voltage and fed through the power supply switching means 4a.

  At this time, the power source switching means 4a eliminates the loss of the forward voltage of the diode during stack power generation, so that there is a diode between the input from the AC / DC converter 1 and the output to the actuator (or control means) 5. However, there is no diode between the input from the stack cutting means 2 and the output to the actuator (or control means) 5.

  Therefore, when the driving power source of the actuator (or control means) 5 is supplied by the AC / DC converter 1 during the start-up of the fuel cell power generation system, the output voltage of the AC / DC converter 1 is on the stack 3 side. Flows in.

  In such a state, a reverse voltage is applied to the stack 3, causing a failure such as shortening the life of the stack 3 or destroying the stack 3. Therefore, when the fuel cell power generation system is not generating power, the stack cutting means 2 separates the stack 3 in order to prevent reverse voltage application to the stack 3.

  When the fuel cell power generation system is ready for power generation, power can be supplied from the stack 3. Since the fuel cell power generation system is a self-generating system, the drive power of the actuator (or control means) 5 such as a valve or a pump in the system is supplied from the self-generated stack 3 to increase the power generation efficiency. It is an effective means.

  Therefore, when power generation is started, the stack cutting means 2 connects the drive power supply path of the stack 3 and the actuator (or control means) 5 so that power can be supplied.

  If the stack 3 and the drive power supply path are connected, as described above, the fuel cell power generator system of the present embodiment sets the minimum output voltage of the stack 3 as 15 V and the output voltage of the AC / DC converter 1 as an example. Is set to 12 V, the power of the actuator (or control means) 5 is always supplied from the stack 3 side where the voltage is high whenever power generation is started.

  In this way, the drive power supply of the actuator (or control means) 5 is operated by switching between the case where the AC voltage of the system power supply 6 is converted into a DC voltage by the AC / DC converter 1 and the case where the AC power is supplied from the stack 3. In the system, by setting the output voltage of the AC / DC converter 1 to a set voltage lower than the lowest output voltage of the stack 3, the system power supply 6 is disconnected from the input side of the AC / DC converter 1 and the output of the AC / DC converter 1 is output. The power supply to the actuator (or the control means) 5 can be supplied from the stack 3 side during power generation without using a component such as a relay that turns off the power. Therefore, the number of components can be reduced and the power supply switching structure is inexpensive. And the number of parts is reduced, so that the stable operation of the system can be improved.

  Further, when supplying power to the actuator (or control means) 5 from the system power supply 6 side, a diode is connected to the output of the AC / DC converter 1, but the power to the actuator (or control means) 5 is supplied from the stack 3 side. In the case of supply, power is supplied without passing through a diode, and the power supply of the actuator (or control means) 5 is supplied from the two power supply paths, while the actuator (or control means) 5 is supplied from the stack 3 side. When power is supplied, the loss of the diode can be eliminated, so that the power generated by the stack 3 can be used effectively, and the power generation efficiency of the fuel cell power generation system can be improved.

  As described above, in the fuel cell power generation system according to the present embodiment, the AC voltage of the stack 3, the actuator or control means 5, and the system power supply 6 in which hydrogen gas and oxygen are reacted to generate power is preset. The AC / DC converter 1 for converting to a DC voltage (12V) lower than the lowest output voltage (15V) of the stack 3 and the power supply to the actuator or the control means 5 are supplied to the output side of the AC / DC converter 1 or the output side of the stack 3 A power source switching means 4a for switching to either one, and a stack cutting means 2 for turning on the connection between the stack 3 and the power source switching means 4a when the power generation of the stack 3 is started and turning off when the power generation of the stack 3 is stopped. Between the input and output on the AC / DC converter 1 side, there is a diode whose forward direction is from the input to the output. It has become no diode configuration between the output and the input of the stack cutter 2 side.

  The power supply switching means 4a in the fuel cell power generator system of the present embodiment has a diode for preventing backflow between the input and output on the system power supply 6 (AC / DC converter 1) side, but the stack 3 (stack disconnection). Since there is no diode between the input and output on the means 2) side, the stack 3 is not generating power, or the output voltage of the stack 3 is lower than the output voltage (12V) of the AC / DC converter 1 In addition, when power is supplied to the actuator (or control means) 5 from the system power supply 6 side, power is supplied via a diode, but the output voltage of the stack 3 is the output voltage (12 V) of the AC / DC converter 1. When the voltage is higher than 15 V and power is supplied to the actuator (or control means) 5 from the stack 3 side, power is supplied without going through a diode. Then, after the stack 3 generates power (power generation of a preset minimum output voltage (15V) or more), the power source is switched from the system power supply (commercial power) 6 to the stack 3, so that the system operation is stable. In the case where power is supplied to the actuator (or control means) 5 from the stack 3 side while maintaining the configuration in which power is supplied to the actuator (or control means) 5 from two power supply paths, Therefore, the generated power of the stack 3 can be used effectively, and the power generation efficiency of the fuel cell power generation system can be improved.

  In addition, since the power supply source is switched from the system power supply (commercial power supply) 6 to the stack 3 after the stack 3 generates power (power generation of a preset minimum output voltage (15V) or more), the system operation is stable. Can keep sex.

  Further, in the power supply switching means 4a, there is a backflow prevention diode between the input and output on the system power supply 6 (AC / DC converter 1) side, in which the direction from the input to the output is the forward direction. Since the converter 1 converts the AC voltage of the system power supply 6 into a DC voltage (12V) lower than the minimum output voltage (15V) of the stack 3, the stack 3 normally operates on the minimum output voltage (15V) of the stack 3. When the power is generated with the power of 1, the power is always supplied to the actuator (or control means) 5 from the stack 3 side without turning off (cutting off) the connection between the system power supply 6 and the AC / DC converter 1. Therefore, when the stack 3 is generating electricity normally, the AC / DC converter 1 is turned on so that power is not supplied to the actuator (or control means) 5 from the system power supply 6 side. A component that cuts off the connection between the power supply 6 and the system power supply 6 (for example, a relay) can be provided, and a component that cuts off the connection between the input of the AC / DC converter 1 and the system power supply 6 (for example, Since the control of the relay (relay) is also unnecessary, the control of the fuel cell power generation system is simplified, the configuration is simple and the number of parts can be reduced, and the fuel cell power generation system is inexpensive and has improved stable operation. A system can be realized.

  In addition, when a component that cuts off the connection between the input of the AC / DC converter 1 and the system power supply 6 (for example, a relay (relay)) is omitted, the output voltage of the stack 3 temporarily decreases (instantaneously). Even if the output voltage (12 V) of the AC / DC converter 1 becomes lower, the power supply switching means 4a automatically and instantaneously switches the power supply to the actuator (or control means) 5 from the stack 3 side to the system power supply 6 side. Therefore, the stability of the fuel cell power generator system is improved.

  Further, even if there is no backflow prevention diode between the input and output on the stack cutting means 2 side in the power supply switching means 4a, the connection between the stack 3 and the power supply switching means 4a is turned on by the start of power generation of the stack 3. Since there is a stack cutting means 2 that is turned off when power generation is stopped at 3, power inflow from the AC / DC converter 1 side to the stack 3 can be prevented when the stack 3 is not generating power. By applying a reverse voltage to 3, it is possible to prevent a failure such as the life of the stack 3 being shortened or the stack 3 being destroyed.

  Further, when the output voltage of the AC / DC converter 1 becomes higher than the output voltage (15V or more) of the stack 3 due to an abnormal operation of the AC / DC converter 1, the power is switched by the stack cutting means 2. If the connection between the means 4a and the stack 3 is cut off, the inflow of electric power to the stack 3 can be prevented, so that it is possible to prevent the expansion of the failure damage during abnormal operation of the fuel cell power generation system. it can.

(Embodiment 2)
FIG. 2 shows an example of a configuration diagram of the fuel cell power generation system according to Embodiment 2 of the present invention.

  In this embodiment, in the configuration of the fuel cell power generation system according to the first embodiment, the stack cutting means 2 causes the lowest output of the stack 3 when the output voltage of the AC / DC converter 1 is higher than normal during power generation of the stack 3. When the voltage exceeds a predetermined voltage equal to or lower than the voltage, the connection between the stack 3 and the power supply switching means 4a is turned off.

  Specifically, in the present embodiment, an AC / DC output voltage measuring means 7 for measuring (monitoring) the output voltage of the AC / DC converter 1 is provided in the configuration of the fuel cell power generator system in the first embodiment. The output voltage of the AC / DC converter 1 connected to the stack cutting means 2 and generating power of the stack 3 and measured by the AC / DC output voltage measuring means 7 is higher than 12V in the normal state, and the minimum output voltage of the stack 3 ( 15V) When the voltage is lower than a predetermined voltage (for example, 15V) (normally), the stack cutting means 2 connects the stack 3 and the power source switching means 4a, and the stack 3 is generating power, and AC / DC The output voltage of the AC / DC converter 1 measured by the output voltage measuring means 7 exceeds a predetermined voltage (for example, 15V) which is higher than the normal 12V and lower than the lowest output voltage (15V) of the stack 3. That becomes voltage (error occurs), the stack cutter 2 is turned configured to cut off the connection between the stack 3 and the power supply switching means 4a (OFF).

  Since other configurations and operations are the same as those of the fuel cell power generation system according to Embodiment 1, the description thereof is omitted.

  For example, even when the output voltage of the AC / DC converter 1 is set to 12V and the minimum output voltage of the stack 3 is set to 15V, the AC / DC converter 1 may have AC / DC converter 1 due to a failure or malfunction of the voltage feedback circuit. It is conceivable that the output voltage of the DC converter 1 becomes higher than the stack voltage.

  At this time, in the configuration of the fuel cell power generation system of the present embodiment, when the power source of the actuator (or control means) 5 is supplied from the stack 3 side, power is supplied without going through the diode. If the cutting means 2 maintains the state in which the connection between the stack 3 and the power supply switching means 4a is kept ON, the output voltage of the AC / DC converter 1 flows backward to the stack 3 side. In such a state, a reverse voltage is applied to the stack 3, which causes a failure such as shortening the life of the stack 3 or destroying the stack 3.

  In the fuel cell power generator system of the present embodiment, the output voltage of the AC / DC converter 1 is monitored by the AC / DC output voltage measuring means 7 during the power generation of the stack 3, and the output voltage is a predetermined voltage, for example, the stack 3 When the voltage exceeds the same voltage as the minimum output voltage (15 V), the stack cutting means 2 can disconnect the stack 3 and the power supply path for driving the actuator, thereby preventing application of a reverse voltage.

  In the present embodiment, the output voltage of the AC / DC converter 1 in which the stack cutting means 2 performs the cutting operation during the power generation of the stack 3 is 15 V. However, the output voltage may be a voltage exceeding 12 V but less than 15 V.

  In this way, the output voltage of the AC / DC converter 1 during the power generation of the stack 3 while the power generation efficiency is increased by supplying the driving power to the actuator (or control means) 5 without using a diode during the stack power generation. If the output voltage of the AC / DC converter 1 is abnormal (when the voltage exceeds 15V), the stack cutting means 2 disconnects the stack 3 and the power supply path for driving the actuator, thereby AC / DC Even when the converter 1 fails, it is possible to prevent the expansion damage such as a decrease in the life of the stack 3 and the failure, so that the reliability of the system can be improved.

  As described above, the present embodiment is provided with the AC / DC output voltage measuring means 7 for measuring (monitoring) the output voltage of the AC / DC converter 1 in the configuration of the fuel cell power generator system according to the first embodiment. The AC / DC converter 1 is connected to the disconnecting means 2 and the AC / DC output voltage measuring means 7 is measuring the output voltage of the stack 3 during power generation, and the output voltage of the stack 3 is higher than the predetermined voltage (normal output voltage 12V). The stack cutting means 2 connects the stack 3 and the power source switching means 4a when the voltage is less than the predetermined output voltage of 15V or less (normal time), and the stack 3 is generating power and AC. The output voltage of the AC / DC converter 1 measured by the DC / DC output voltage measuring means 7 is a predetermined voltage (higher than the normal output voltage of 12 V and lower than the minimum output voltage of the stack 3 of 15 V or less. It becomes the voltage exceeding a predetermined voltage) and (abnormality occurs), the stack cutter 2 is that configured to cut off the connection between the stack 3 and the power supply switching means 4a (OFF).

  As a result, the stack cutting means 2 can be appropriately automatically opened and closed during the power generation of the stack 3, and the output voltage of the stack 3 is normally output when the output voltage of the AC / DC converter 1 is lower than a predetermined voltage (for example, 15V). When the voltage is higher than the output voltage of the AC / DC converter 1, the stack cutting means 2 connects the stack 3 and the power supply switching means 4a, so that power is supplied to the actuator (or control means) 5 from the stack 3 side. If an abnormality occurs while power is being supplied from the stack 3 side to the actuator (or control means) 5, the output voltage of the AC / DC converter 1 exceeds a predetermined voltage (for example, 15V). The stack cutting means 2 cuts off the connection between the stack 3 and the power supply switching means 4a (OFF), and the output voltage of the AC / DC converter 1 Even when higher than the output voltage of the stack 3, it is possible to prevent the inflow of abnormal power to the stack 3, it is possible to prevent the spread of failure damage during abnormal operation of the fuel cell power generation system.

  Further, when the output voltage of the AC / DC converter 1 returns from a voltage exceeding a predetermined voltage (for example, 15V) to a predetermined voltage (for example, 15V) or less, if the predetermined condition is satisfied (for example, the output of the AC / DC converter 1) An abnormality in which the voltage exceeds a predetermined voltage (for example, 15V) is temporary, and when the output voltage of the AC / DC converter 1 immediately returns to 12V that is equal to or lower than the predetermined voltage (for example, 15V), or the AC / DC converter If the output voltage of 1 exceeds a predetermined voltage (for example, 15V), but the voltage value exceeding is relatively small), the stack cutting means 2 connects the stack 3 and the power supply switching means 4a again. Again, power can be supplied to the actuator (or control means) 5 from the stack 3 side.

(Embodiment 3)
FIG. 3 shows an example of a configuration diagram of the fuel cell power generation system according to Embodiment 3 of the present invention.

  In the present embodiment, the output voltage from the stack 3 or the AC / DC converter 1 is applied between the power supply switching unit 4a and the actuator (or control unit) 5 in the configuration of the fuel cell power generation system of the second embodiment. A DC / DC converter 8 for supplying electric power to the actuator (or control means) 5 in place of a predetermined voltage (for example, 24V, 12V, 5V) is provided. Since other configurations and operations are the same as those of the fuel cell power generation system according to Embodiment 2, the description thereof is omitted.

  In the present embodiment, the power source switching means 4a is supplied with power when the actuator (or control means) 5 is supplied with power from the output side of the stack 3 and when power is supplied from the output side of the AC / DC converter 1. When the power is supplied from the output side of the stack 3 due to a difference in the voltage on the output side or when the output power of the stack 3 fluctuates, the power is supplied from the output side of the AC / DC converter 1 In the case of supplying, the trouble caused by the fluctuation of the output voltage of the AC / DC converter 1 can be solved by the DC / DC converter 8, and the actuator (or control means) 5 can be supplied with a stable voltage.

  In this embodiment, a DC / DC converter 8 is provided between the power supply switching unit 4a and the actuator (or control unit) 5 in the configuration of the fuel cell power generation system of the second embodiment. A DC / DC converter 8 may be provided between the power supply switching unit 4a and the actuator (or control unit) 5 in the configuration of the fuel cell power generator system of the first embodiment.

(Embodiment 4)
FIG. 4 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 4 of the present invention.

  In the present embodiment, in the configuration of the fuel cell power generation system according to the first embodiment, instead of the power supply switching unit 4a, an input on the AC / DC converter 1 side and an output on the actuator (or control unit) 5 side There is a power supply switching means 4b having a diode-or configuration in which there is a diode whose forward direction is the direction toward the output between both the gap and the input on the stack cutting means 2 side and the output on the actuator (or control means) 5 side. In addition, short-circuit means 9 for short-circuiting the input and output on the stack cutting means 2 side in the power supply switching means 4b when the power generation of the stack 3 is started and releasing the short-circuit when the power generation of the stack 3 is stopped is provided.

  Since other configurations and operations are the same as those of the fuel cell power generation system according to Embodiment 1, the description thereof is omitted.

  In the present embodiment, the power supply switching means 4b is provided between the input on the system power supply 6 (or AC / DC converter 1) side and the output on the actuator (or control means) 5 side, and the stack 3 (or stack cutting means). 2) There is a so-called diode-or configuration in which there is a backflow prevention diode whose forward direction is the direction between the input on the side and the output on the actuator (or control means) 5 side. Short-circuit means for short-circuiting the input on the stack cutting means 2 side and the output to the actuator (or control means) 5 side in the switching means 4b when the power generation of the stack 3 is started and releasing (cut-off) the short-circuit when the power generation of the stack 3 is stopped. 9, an input on the stack cutting means 2 side and an output on the actuator (or control means) 5 side in the power supply switching means 4b Is short-circuited (during stack power generation), the configuration is substantially the same as in the first embodiment, and when the power of the actuator (or control means) 5 is supplied from the stack 3 side, There is no problem that the power decreases the efficiency by the amount of the diode loss, and the same operation and effect as in the first embodiment can be obtained.

  Further, when the stack 3 is not generating power, the input to the stack cutting means 2 side and the output to the actuator (or control means) 5 side in the power supply switching means 4b are not short-circuited, and the power supply switching means 4b The direction toward the output to the actuator (or control means) 5 side becomes the forward direction between the input on the stack 3 (or stack cutting means 2) side and the output to the actuator (or control means) 5 side in FIG. Since the provided backflow prevention diode becomes effective, there is a problem or failure that the stack cutting means 2 does not turn off the connection while the connection between the stack 3 and the power supply switching means 4b remains on (for example, Even if the stack cutting means 2 is a component such as a relay and the contact point of the relay has a short circuit failure) Inflow of electric power from the AC / DC converter 1 side to the stack 3 can be prevented, whereby a reverse voltage is applied to the stack 3, thereby shortening the life of the stack 3 or destroying the stack 3. Such a failure can be prevented.

  Further, when the output voltage of the AC / DC converter 1 exceeds a predetermined voltage (a predetermined voltage higher than 12V of the normal output voltage and lower than 15V which is the lowest output voltage of the stack 3), the short-circuit means 9 If the short circuit between the input on the stack 3 (or stack cutting means 2) side and the output to the actuator (or control means) 5 side in the power supply switching means 4b is released, the stack cutting means 2 is connected to the stack 3 If there is a problem or failure that does not turn off the connection while the connection between the power supply switching means 4b and the power supply switching means 4b is ON (for example, the stack cutting means 2 is a component such as a relay and the contact portion of the relay is short-circuited) Even if a failure occurs, abnormal power inflow into the stack 3 can be prevented, so that the power generation efficiency of the fuel cell can be improved. And it is possible to prevent the spread of failure damage system abnormality Operation (when a component of the system fails).

(Embodiment 5)
FIG. 5 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 5 of the present invention.

  In the present embodiment, in the configuration of the fuel cell power generation system according to the fourth embodiment, the short-circuit means 9 causes the lowest output voltage of the stack 3 when the output voltage of the AC / DC converter 1 is higher than normal during power generation of the stack 3. When the voltage exceeds the following predetermined voltage, the short circuit between the input on the stack cutting means 2 side and the output on the actuator (or control means) 5 side in the power supply switching means 4b is released.

  Specifically, in the present embodiment, AC / DC output voltage measuring means 7 for measuring (monitoring) the output voltage of the AC / DC converter 1 is provided in the configuration of the fuel cell power generation system in the fourth embodiment. The short-circuit means is connected to 9, the power generation of the stack 3, and the output voltage of the AC / DC converter 1 measured by the AC / DC output voltage measurement means 7 is higher than 12V in the normal state and the minimum output voltage of the stack 3 ( 15V) When the voltage is less than a predetermined voltage (for example, 15V) (normally), the short-circuit means 9 is between the input to the stack cutting means 2 side and the output to the actuator (or control means) 5 side in the power supply switching means 4b. , The output voltage of the AC / DC converter 1 measured by the AC / DC output voltage measuring means 7 is higher than 12V in the normal state, and the stack 3 is generating power. When the voltage exceeds a predetermined voltage (for example, 15V) lower than the minimum output voltage (15V) (an abnormality occurs), the short-circuit means 9 receives the input on the stack cutting means 2 side in the power supply switching means 4b and the actuator (or control means). It is the structure which cancels | releases (cuts off) the short circuit between the outputs to 5 side.

  Other configurations and operations are the same as those of the fuel cell power generation system according to the fourth embodiment, and a description thereof will be omitted.

  With the above configuration, the short-circuit means 9 can be appropriately automatically opened and closed during power generation of the stack 3, and the output voltage of the AC / DC converter 1 is higher than the normal 12V and lower than the minimum output voltage (15V) of the stack 3. When the output voltage of the stack 3 is higher than the output voltage of the AC / DC converter 1 at a normal time of a predetermined voltage (for example, 15V) or less, the stack cutting means 2 connects the stack 3 and the power supply switching means 4b. The power can be supplied to the actuator (or control means) 5 from the stack 3 side. In this case, since the short-circuit means 9 is in the short-circuit state, the loss of the diode can be eliminated, and the stack 3 is generating power. The output voltage of the AC / DC converter 1 exceeds a predetermined voltage (for example, 15V) which is higher than the normal 12V and lower than the minimum output voltage (15V) of the stack 3. When an abnormality occurs, the short-circuit means 9 releases (cuts off) the short-circuit, and between the input on the stack 3 (or stack cutting means 2) side and the output on the actuator (or control means) 5 side in the power supply switching means 4b. Since the backflow prevention diode provided so that the direction toward the output to the actuator (or control means) 5 becomes the forward direction is effective, the stack cutting means 2 is connected to the stack 3 and the power supply switching means 4b. When there is a malfunction or failure that does not turn off the connection while the connection is ON (for example, when the stack cutting means 2 is a component such as a relay and the contact point of the relay has a short failure) However, abnormal power inflow to the stack 3 can be prevented.

  Also, when the output voltage of the AC / DC converter 1 returns from a voltage higher than 12V in the normal state and exceeding a predetermined voltage (for example, 15V) below the minimum output voltage (15V) of the stack 3 to a predetermined voltage (for example, 15V) or less. If, for example, the predetermined condition is satisfied (for example, an abnormality in which the output voltage of the AC / DC converter 1 exceeds the predetermined voltage is temporary, the output voltage of the AC / DC converter 1 immediately returns below the predetermined voltage. In other cases, or when the output voltage of the AC / DC converter 1 exceeds a predetermined voltage, but the voltage value exceeding the predetermined voltage is relatively small), the shorting means 9 is connected to the input on the stack cutting means 2 side and the actuator (or control means) 5. If the configuration is such that the output to the side is short-circuited again, the short-circuit means 9 returns to the original short-circuit state, whereby the actuator (or control means) 5 is transferred from the stack 3 side. Source can be eliminated loss of the diode when supplying.

(Embodiment 6)
FIG. 6 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 6 of the present invention.

  In the present embodiment, in the configuration of the fuel cell power generation system according to the fifth embodiment, the stack cutting means 2 causes the lowest output of the stack 3 when the output voltage of the AC / DC converter 1 is higher than normal during power generation of the stack 3. When the voltage exceeds a predetermined voltage equal to or lower than the voltage, the connection between the stack 3 and the power supply switching unit 4b is turned off.

  Specifically, in the present embodiment, the AC / DC output voltage measuring means 7 in the configuration of the fuel cell power generator system of the fifth embodiment is connected to both the short-circuit means 9 and the stack cutting means 2, and the stack 3 During power generation, the output voltage of the AC / DC converter 1 measured by the AC / DC output voltage measuring means 7 is higher than 12V in the normal state and lower than a predetermined voltage (for example, 15V) lower than the lowest output voltage (15V) of the stack 3. (Normally), the stack cutting means 2 connects the stack 3 and the power supply switching means 4b, and the short circuit means 9 is connected to the input of the power supply switching means 4b on the stack cutting means 2 side and the actuator (or control means). The output voltage of the AC / DC converter 1 measured by the AC / DC output voltage measuring means 7 during the power generation of the stack 3 is short-circuited with the output to the 5 side. When the voltage exceeds a predetermined voltage (for example, 15V) higher than the usual 12V and lower than the minimum output voltage (15V) of the stack 3 (an abnormality occurs), the stack cutting means 2 connects the stack 3 and the power supply switching means 4b. Is cut off (OFF), and the short-circuit means 9 releases the short-circuit between the input to the stack cutting means 2 side and the output to the actuator (or control means) 5 side in the power supply switching means 4b. Yes.

  Other configurations and operations are the same as those of the fuel cell power generation apparatus system according to the fourth embodiment or the fifth embodiment, and thus description thereof is omitted.

  With the above configuration, both the short-circuit means 9 and the stack cutting means 2 can be appropriately automatically opened and closed during power generation of the stack 3, and the output voltage of the AC / DC converter 1 is higher than the normal 12V and the lowest of the stack 3 When the output voltage of the stack 3 is higher than the output voltage of the AC / DC converter 1 at a normal time of the predetermined voltage (for example, 15 V) or less, which is lower than the output voltage (15 V), the stack cutting means 2 is switched between the stack 3 and the power supply switching means 4 b. Can be supplied to the actuator (or control means) 5 from the stack 3 side. In this case, since the short-circuit means 9 is in a short-circuit state, the loss of the diode can be eliminated. .

  Further, during the supply of power to the actuator (or control means) 5 from the stack 3 side, the output voltage of the AC / DC converter 1 is higher than the normal 12V and lower than the minimum output voltage (15V) of the stack 3. When an abnormality exceeding a predetermined voltage (for example, 15 V) occurs, the short circuit means 9 releases (cuts off) the short circuit, and the stack cutting means 2 cuts off (OFF) the connection between the stack 3 and the power supply switching means 4b. Even when the output voltage of the DC / DC converter 1 becomes higher than the output voltage of the stack 3, it is possible to prevent the abnormal power from flowing into the stack 3 and to expand the damage caused by the malfunction of the fuel cell power generation system. Can be prevented.

  While the power is being supplied to the actuator (or control means) 5 from the tack 3 side, the output voltage of the AC / DC converter 1 is higher than the normal 12V and lower than the minimum output voltage (15V) of the stack 3. Even when there is a malfunction or failure in which the short-circuit means 9 does not release (cut off) the short-circuit when an abnormality exceeding a predetermined voltage (for example, 15V) occurs, the stack cutting means 2 connects the stack 3 and the power supply switching means 4b. By shutting off (OFF), abnormal power inflow to the stack 3 can be prevented, and conversely, the stack cutting means 2 does not turn off the connection while the connection between the stack 3 and the power supply switching means 4b remains on. Even if there is a failure, if the short-circuit means 9 releases (cuts off) the short-circuit, the stack 3 (or stack cutting means 2) side in the power supply switching means 4b A backflow prevention diode provided in such a way that the direction toward the output to the actuator (or control means) 5 side becomes the forward direction between the input and the output to the actuator (or control means) 5 side becomes effective. Therefore, abnormal power inflow to the stack 3 can be prevented.

  Also, when the output voltage of the AC / DC converter 1 returns from a voltage higher than 12V in the normal state and exceeding a predetermined voltage (for example, 15V) below the minimum output voltage (15V) of the stack 3 to a predetermined voltage (for example, 15V) or less. In addition, if the predetermined condition is satisfied (for example, an abnormality in which the output voltage of the AC / DC converter 1 exceeds a predetermined voltage (for example, 15V) is temporary, the output voltage of the AC / DC converter 1 immediately becomes the predetermined voltage. When the voltage returns to 12V below, or when the output voltage of the AC / DC converter 1 is higher than 12V in the normal state and exceeds a predetermined voltage (for example, 15V) lower than the minimum output voltage (15V) of the stack 3, Is relatively small), the short-circuit means 9 again short-circuits between the input to the stack cutting means 2 side and the output to the actuator (or control means) 5 side, If the means 2 is configured so as to connect the stack 3 and the power supply switching means 4b again, the actuator (or control means) 5 from the stack 3 side again with the diode loss of the power supply switching means 4b eliminated. Power can be supplied.

(Embodiment 7)
FIG. 7 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 7 of the present invention.

  In the present embodiment, the output voltage from the stack 3 or the AC / DC converter 1 is set between the power supply switching unit 4b and the actuator (or control unit) 5 in the configuration of the fuel cell power generation system of the sixth embodiment. A DC / DC converter 8 for supplying electric power to the actuator (or control means) 5 in place of a predetermined voltage (for example, 24V, 12V, 5V) is provided. Other configurations and operations are the same as those of the fuel cell power generation system according to the sixth embodiment, and a description thereof will be omitted.

  In the present embodiment, the power source switching means 4b is supplied with power to the actuator (or control means) 5 from the output side of the stack 3 and when power is supplied from the output side of the AC / DC converter 1. When the power is supplied from the output side of the stack 3 due to a difference in the voltage on the output side or when the output power of the stack 3 fluctuates, the power is supplied from the output side of the AC / DC converter 1 In the case of supplying, the trouble caused by the fluctuation of the output voltage of the AC / DC converter 1 can be solved by the DC / DC converter 8, and the actuator (or control means) 5 can be supplied with a stable voltage.

  In this embodiment, a DC / DC converter 8 is provided between the power supply switching means 4b and the actuator (or control means) 5 in the configuration of the fuel cell power generation system of the sixth embodiment. A DC / DC converter 8 may be provided between the power supply switching unit 4b and the actuator (or control unit) 5 in the configuration of the fuel cell power generator system of Embodiment 4 or Embodiment 5.

(Embodiment 8)
FIG. 8 shows an example of a configuration diagram of a fuel cell power generation system according to Embodiment 8 of the present invention.

  In the present embodiment, in the configuration of the fuel cell power generation system according to the seventh embodiment, the connection between the system power supply 6 and the AC / DC converter 1 is turned on before the stack 3 starts power generation, and the stack 3 has the lowest output voltage. (15V) The system disconnection means 10 that is turned off when power generation is started is provided, and the AC / DC output voltage measuring means 7 detects the state of the system disconnection means 10 based on the output voltage of the AC / DC converter 1 to disconnect the system. When the AC / DC output voltage measuring means 7 detects that the means 10 is turned on, the short circuit means 9 releases (cuts off) the short circuit, and the stack cutting means 2 connects the stack 3 and the power supply switching means 4b. When the AC / DC output voltage measuring means 7 detects that the system disconnecting means 10 is turned off, the shorting means 9 is short-circuited and the stack cutting means 2 is Tack 3 and those configured to connect the power source switching unit 4b.

  In the configuration of the present embodiment, the system disconnection means 10 for controlling ON / OFF of the output of the AC / DC converter 1 is provided on the input side of the AC / DC converter 1, and the stack 3 has a minimum output voltage (15V) or more. When the power generation is started, the system disconnection unit 10 disconnects the input of the AC / DC converter 1, thereby turning off the output of the AC / DC converter 1. When the AC / DC output voltage measuring means 12 detects that the output of the AC / DC converter 1 is turned off, the short circuit means 9 causes the input on the stack 3 (or stack cutting means 2) side and the actuator (or control means) in the power supply switching means 4b. Between the output to the 5 side and the output to the actuator (or control means) 5 side, the diode for backflow prevention provided so that the direction toward the output to the 5 side becomes the forward direction is short-circuited. Specifically, for example, when the short-circuit means 9 is configured by a normally closed type relay, if the output of the AC / DC converter 1 is used as a coil drive voltage of the relay, it is a normally closed relay. When the input of the DC converter 1 is connected to the system and a voltage is output, the relay is turned on, so the contact part of the relay is in an open state, that is, a state with a diode.

  When the stack 3 starts generating power of the minimum output voltage (15V) or more, the system disconnection means 10 disconnects the input of the AC / DC converter 1, so that the output of the AC / DC converter 1 is turned off. Therefore, the relay contact portion is in a closed state, that is, a state without a diode (a diode is short-circuited).

  Thus, for example, when power is being supplied from the system side during system startup, the output voltage of the AC / DC converter 1 is normal, but the stack cutting means 2 is a component such as a relay. In some cases, a diode is also provided between the input from the stack cutting means 2 and the output to the actuator (or control means) 5 even when the contact point of the relay has a short circuit failure. Thus, the inflow of electric power from the AC / DC converter 1 side to the stack 3 can be prevented. By applying a reverse voltage to the stack 3, the life of the stack 3 is shortened or the stack 3 is Failures such as destruction can be prevented, and expansion of failure damage when one component of the system fails can be prevented.

  In addition, after power generation is started, the input of the AC / DC converter 1 is turned off to stop the output of the AC / DC converter 1, and the output from the stack cutting means 2 and the DC / DC converter 11 are stopped. By adopting a configuration that short-circuits the diode between the inputs, it is possible to prevent a diode loss of the stack power during power generation while maintaining a configuration that prevents the above-described system damage from being expanded. It is possible to improve the power generation efficiency.

  As described above, the fuel cell power generation system according to the present embodiment uses the AC voltage of the stack 3, the actuator (or control means) 5, and the system power supply 6 that generates power by reacting hydrogen gas and oxygen with the DC voltage. An AC / DC converter 1 for converting to power, a power supply switching means 4b for switching power supply to the actuator (or control means) 5 to either the output side of the AC / DC converter 1 or the output side of the stack 3, and a system power supply 6 The connection to the AC / DC converter 1 is turned on before the stack 3 starts power generation, and the system disconnection means 10 that is turned off when the stack 3 starts power generation above the minimum output voltage, and the output voltage of the AC / DC converter 1 is measured. Then, the AC / DC output voltage measuring means 7 for detecting the state of the system disconnecting means 10 and the connection between the stack 3 and the power supply switching means 4b are disconnected. Stack cutting means 2 which turns on when AC / DC output voltage measuring means 7 detects that stage 10 is turned off and turns off when AC / DC output voltage measuring means 7 detects that system disconnection means 10 is turned on. When the AC / DC output voltage measuring means 7 detects that the system disconnection means 10 is turned off between the input and output on the stack cutting means 2 side in the power supply switching means 4b, the system disconnection means 10 is turned on. When the AC / DC output voltage measuring means 7 detects that the short circuit has occurred, the short circuit means 9 for releasing the short circuit is provided. The power supply switching means 4b is provided between the input and output on the AC / DC converter 1 side and the stack cutting means. There is a diode having a forward direction in the direction toward the output between both the input and output on the two sides.

  In the above configuration, when the system disconnection means 10 is turned on before the stack 3 starts power generation, the AC / DC converter 1 converts the AC voltage of the system power supply 6 into a DC voltage, and the output of the AC / DC converter 1 is the power supply. It is sent to the actuator (or control means) 5 via the switching means 4b, and the actuator (or control means) 5 is supplied with electric power from the output side of the AC / DC converter 1 via the power supply switching means 4b. At this time, when the AC / DC output voltage measuring means 7 detects that the system disconnecting means 10 is turned on based on the output voltage of the AC / DC converter 1, the stack disconnecting means 2 is connected to the stack 3 and the power supply switching means. Since the connection with 4b is OFF and the short-circuit means 9 does not short-circuit between the input and output on the stack cutting means 2 side in the power supply switching means 4b, the AC / DC converter 1 side to the stack 3 is not connected. Inflow of electric power can be prevented, and thereby, a reverse voltage is applied to the stack 3, thereby preventing a failure such as shortening the life of the stack 3 or destroying the stack 3.

  At this time, even if the short-circuit means 9 has a problem or failure and is short-circuited, if the stack cutting means 2 turns off the connection between the stack 3 and the power supply switching means 4b, the AC / DC to the stack 3 Inflow of power from the converter 1 side can be prevented, and conversely, even if the stack cutting means 2 has a malfunction or failure and the connection between the stack 3 and the power supply switching means 4b is in the ON state, the shorting means 9 is not short-circuited between the input and output on the stack cutting means 2 side in the power supply switching means 4b, the diode between the input and output on the stack cutting means 2 side in the power supply switching means 4b is directed to the stack 3 side. Therefore, the inflow of electric power from the AC / DC converter 1 side to the stack 3 can be prevented.

  When the stack 3 starts power generation at the minimum output voltage or higher, the system disconnection unit 10 turns off the connection between the system power supply 6 and the AC / DC converter 1. When the input of the AC / DC converter 1 is disconnected by turning off the system disconnection means 10, the output of the AC / DC converter 1 is turned off, and the system disconnection means 10 is turned off based on the output voltage of the AC / DC converter 1. When the AC / DC output voltage measuring means 7 detects this, the stack cutting means 2 turns on the connection between the stack 3 and the power supply switching means 4b, and the short circuit means 9 is connected to the input on the stack cutting means 2 side of the power supply switching means 4b. Since the output is short-circuited, the output of the stack 3 is sent to the actuator (or control means) 5 via the short-circuit means 9 instead of passing through the power supply switching means 4b (diode).

  Thus, when power is supplied to the actuator (or control means) 5 from the stack 3 side, the loss of the diode can be eliminated, so that the generated power of the stack 3 can be used effectively, and the fuel cell power generation The power generation efficiency of the device system can be improved.

  Further, when power is supplied from the stack 3 side to the actuator (or control means) 5, the system disconnection means 10 turns off the connection between the system power supply 6 and the AC / DC converter 1. Can be prevented from flowing in from the AC / DC converter 1 side.

  Further, the output voltage from the stack 3 or the AC / DC converter 1 is changed to a predetermined voltage (for example, 24V, 12V, 5V) between the power supply switching unit 4b and the actuator (or control unit) 5, and the actuator (or control). Means) By providing the DC / DC converter 8 for supplying power to 5, the actuator (or control means) 5 is supplied with power from the output side of the stack 3, and from the output side of the AC / DC converter 1. A problem caused by the voltage on the output side of the power supply switching means 4b being different between when power is supplied, or a problem caused by fluctuations in the output power of the stack 3 when power is supplied from the output side of the stack 3, Alternatively, when power is supplied from the output side of the AC / DC converter 1, the output voltage of the AC / DC converter 1 varies. A defect due to, be solved by a DC / DC converter 8, the actuator (or control means) may be powered by 5 to a stable voltage.

The fuel cell power generation system of the present invention is a fuel cell power generation system including power supply switching means for switching power supply to the actuator or control means to either the system power supply side or the stack side. When power is supplied to the control means, a part of the power generated by the stack is not consumed (lost) by the power switching means, and the power generated by the stack can be used effectively, the configuration is simple, low cost, and reliability Therefore, it is suitable for a fuel cell power generation apparatus system that is required to have high efficiency, simple configuration, low cost, and high reliability.
Can be used to improve power generation efficiency during power generation.

1 is a configuration diagram of a fuel cell power generation system according to Embodiment 1 of the present invention. Configuration diagram of a fuel cell power generation system according to Embodiment 2 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 3 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 4 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 5 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 6 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 7 of the present invention Configuration diagram of a fuel cell power generation system according to Embodiment 8 of the present invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 AC / DC converter 2 Stack cutting | disconnection means 3 Stack 4a, 4b Power supply switching means 5 Actuator (or control means)
6 System power supply 7 AC / DC output voltage measurement means 8 DC / DC converter 9 Short circuit means 10 System disconnection means

Claims (6)

A stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, an AC / DC converter for converting an AC voltage of a system power supply to a DC voltage lower than a preset minimum output voltage of the stack, Power supply switching means for switching power supply to the actuator or the control means to either the output side of the AC / DC converter or the output side of the stack, and the connection between the stack and the power supply switching means by the start of power generation of the stack A stack cutting means that turns on and turns off when power generation of the stack is stopped, and the power supply switching means has a forward direction from the input to the output between the input and the output on the AC / DC converter side. However, there is no diode between the input on the stack cutting means side and the output. Characterized in that, the fuel cell power generation system. A stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, an AC / DC converter for converting an AC voltage of a system power supply to a DC voltage lower than a preset minimum output voltage of the stack, Power supply switching means for switching power supply to the actuator or the control means to either the output side of the AC / DC converter or the output side of the stack, and the connection between the stack and the power supply switching means by the start of power generation of the stack The stack cutting means that is turned on and turned off when the power generation of the stack is stopped, and the input and output on the stack cutting means side of the power supply switching means are short-circuited when the power generation of the stack is started, and the short circuit is released when the power generation of the stack is stopped Short-circuiting means, and the power supply switching means includes the AC / DC converter. A fuel cell power generator comprising: a diode having a forward direction directed to the output between the input and output on the data side and between the input and output on the stack cutting means side system. When the output voltage of the AC / DC converter is higher than normal and exceeds a predetermined voltage not higher than the minimum output voltage of the stack during power generation of the stack, the short-circuit means is connected between the input and output on the stack cutting means side in the power supply switching means. The fuel cell power generator system according to claim 2, wherein a short circuit is released. The stack cutting means turns off the connection between the stack and the power supply switching means when the output voltage of the AC / DC converter is higher than normal and exceeds a predetermined voltage lower than the minimum output voltage of the stack during power generation of the stack. The fuel cell power generator system according to any one of claims 1 to 3, characterized by: A stack for generating power by reacting hydrogen gas and oxygen, an actuator or control means, an AC / DC converter for converting an AC voltage of a system power supply to a DC voltage lower than a preset minimum output voltage of the stack, The stack generates power by connecting power supply switching means for switching power supply to the actuator or control means to either the output side of the AC / DC converter or the output side of the stack, and the system power supply and the AC / DC converter. The system disconnection means that is turned on before starting the power supply and turned off when the stack starts power generation of the minimum output voltage or more, and the AC / DC that detects the state of the system disconnection means by measuring the output voltage of the AC / DC converter Connection between the output voltage measuring means, the stack and the power supply switching means is turned off by the system disconnection means. In the stack cutting means that is turned on when the AC / DC output voltage measuring means detects that the system disconnection means is turned on, and in the power supply switching means that is turned off when the AC / DC output voltage measuring means is detected. When the AC / DC output voltage measuring means detects that the system disconnecting means is turned off between the input and output on the stack cutting means side, the AC / DC output voltage measuring means detects a short circuit and the AC disconnecting means is turned on. / DC output voltage measuring means comprises a short-circuit means for releasing the short-circuit, the power supply switching means between the input and output on the AC / DC converter side, the input on the stack cutting means side and the output A fuel cell power generation system characterized in that there is a diode whose forward direction is the direction toward the output between the two. A DC / DC converter is provided between the power supply switching means and the actuator or control means, and changes the output voltage from the stack or the AC / DC converter to a predetermined voltage to supply power to the actuator or control means. The fuel cell power generation system according to any one of claims 1 to 5.

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