JP5271190B2 - Power supply device - Google Patents

Abstract

Disclosed is a power supply apparatus comprising a solar cell power source device which uses a solar cell as the input power source and outputs DC power to a load device, and a control means which controls the output of the solar cell power source device. Furthermore, the output of the solar cell power source device is controlled by regulating the output voltage characteristics of the solar cell power source device associated with the output voltage of the solar cell, so that when the output of the solar cell is being controlled the output voltage of the solar cell is adjusted within a range above the voltage constituting the maximum output power of the solar cell and below the open-circuit voltage of the solar cell.

Description

  The present invention relates to a power supply apparatus in which a plurality of power supply devices including a power supply device using a solar cell as an input power supply operate in parallel to supply DC power to a load device.

  2. Description of the Related Art Conventionally, various types of power supply devices are known as a power supply device that supplies a DC power to a load device by operating a plurality of power devices in parallel.

  As an example of a conventional power supply device, a power supply device including two power supply devices whose output voltage monotonously decreases as the output current increases is known (see, for example, Patent Document 1). In this power supply device, the inclination angles of the output current-output voltage characteristics of the two power supply devices are different. That is, when the output current changes by the same magnitude, the amount of change in the output voltage of one power supply device is different from the amount of change in the output voltage of the other power supply device.

  In the power supply device as described above, each power supply device settles at the balance point between the output current-output voltage characteristics and the load current according to the total use current (load current) of all the load devices, An arbitrary output current can be output from each power supply device at an arbitrary output voltage.

JP-A-10-248253

  However, in a power supply device in which the inclination angles of the output current-output voltage characteristics of the two power supply devices are different, the output voltage of each power supply device, that is, the supply voltage to the load device varies depending on the magnitude of the load current. Therefore, there is a problem that the voltage supplied to the load device cannot be kept stable. For such a power supply device, when the output current of each power supply device is changed to a desired current value, in order to keep the supply voltage to the load device before and after the change of the output current, It is necessary to move both the output current-output voltage characteristics of the two power supply devices horizontally, and the configuration becomes complicated.

  Here, as a means for solving the above problem, among a plurality of power supply devices that operate in parallel, one power supply device performs constant voltage control, and the remaining power supply devices monotonously as the output current increases. A power supply device that performs slope control using a decreasing DC voltage as an output voltage is conceivable. In such a power supply device, the slope control power supply device outputs current to the load device in a state where the output voltage of the slope control power supply device is adjusted to the output voltage (reference voltage) of the constant voltage control power supply device. Thus, the output current-output voltage characteristic is shifted. The shortage of load current is output from the constant voltage control power supply device to the load device. As a result, in this power supply device, even if the load current changes to some extent, the supply voltage to the load device is maintained at a constant voltage (the output voltage of the power supply device under constant voltage control), and power is supplied to the load device. It can be performed stably.

  By the way, a solar cell may be used as a power source connected to the above-described tilt control power source device. When outputting a current to a power supply device (solar cell power supply device) to which a solar cell is connected, the conventional solar cell power supply device has an output current-output voltage so that the output current has a desired magnitude. Shift characteristics.

  However, the output power of the solar cell is unstable due to the influence of the weather, etc., and when the output power of the solar cell is small, when trying to output a current of a desired magnitude from the power supply device for the solar cell, There is a problem that the output voltage of the battery becomes smaller than the voltage that is the maximum output power, and the output of the solar battery is reduced.

  The present invention has been made in view of the above points, and an object of the present invention is to provide a power supply device that can output current from a power supply device to which a solar cell is connected while preventing the output of the solar cell from being reduced. There is.

  The invention of claim 1 includes a constant voltage power supply device that uses a DC voltage that is a constant voltage regardless of the magnitude of the output current as an output voltage, and a DC power that operates in parallel with the constant voltage power supply device using a solar cell as an input power source. For detecting the output current of the solar cell power supply device when the output voltage of the solar cell power supply device is adjusted to the output voltage of the constant voltage power supply device Output current detection means, and control means for setting a target value of the output current of the solar cell power supply device, the solar cell power supply device when the output voltage of the solar cell increases Adjustment means for shifting the output voltage characteristic in which the output voltage of the output voltage monotonously increases, and the control means is configured to adjust the output voltage so that the output current detected by the output current detection means approaches the target value. An instruction for shifting the power is transmitted to the adjusting means, and the adjusting means shifts the output voltage characteristic according to the instruction, and the output voltage of the solar cell power supply device is changed to the constant voltage power supply device. The output voltage of the solar cell when adjusted to the output voltage of the solar cell is adjusted in the range of the voltage at which the solar cell is the maximum output power and less than the open circuit voltage.

  The invention of claim 2 is characterized in that, in the invention of claim 1, the adjustment means sets an upper limit value of the output voltage of the solar cell power supply device in the output voltage characteristics.

  According to a third aspect of the present invention, in the first or second aspect of the present invention, the apparatus includes a temperature detection unit that detects a temperature of the solar cell, and the adjustment unit is configured to detect the output voltage characteristic according to a detection result of the temperature detection unit. The shift amount is corrected.

  The invention according to claim 4 is the invention according to any one of claims 1 to 3, wherein the control means is configured to adjust the adjusting means when the output current detected by the output current detecting means reaches the target value. The transmission of the instruction to is stopped.

  According to the first aspect, since the output voltage of the solar cell is always larger than the voltage at which the maximum output power is obtained, it is possible to output current from the solar cell power supply device while preventing the output of the solar cell from being reduced.

  According to Claim 2, when the upper limit value of the output voltage of the solar cell power supply device is set, the output voltage of the solar cell power supply device temporarily increases when the load current changes rapidly. The amount can be suppressed.

  According to claim 3, since the influence of the temperature characteristic of the solar cell can be reduced, the operation of the solar cell power supply device can be stabilized even if the temperature of the solar cell fluctuates.

  According to the fourth aspect of the present invention, when the output current detected by the output current detection means reaches the target value, the control means stops sending instructions, so that useless control can be eliminated.

It is a block diagram which shows the structure of the principal part in embodiment of this invention. It is a block diagram which shows the whole structure same as the above. It is a circuit diagram of the 1st power supply device which concerns on the same as the above. It is a circuit diagram of the BAT converter and FC converter which concern on the same as the above. (A) is a diagram showing output current-output voltage characteristics of the BAT converter and FC converter according to the above, (b) is a diagram showing output current-output voltage characteristics of the first power supply device according to the above, (c) is It is a figure explaining the output current of the BAT converter and FC converter which concern on the same as the above. It is a figure explaining operation | movement of the BAT converter and FC converter which concern on the same as the above. It is a figure explaining the shift of the output current-output voltage characteristic of the BAT converter and FC converter which concern on the same as the above. It is a circuit diagram of the PV converter which concerns on the same as the above. It is a figure which shows the input voltage-output voltage characteristic of the PV converter which concerns on the same as the above. It is a figure which shows the characteristic of the solar voltage connected to the PV converter which concerns on the same as the above. It is a figure explaining operation | movement of the PV converter which concerns on the same as the above. It is a figure explaining the shift of the input voltage-output voltage characteristic of the PV converter which concerns on the same as the above. It is a flowchart explaining operation | movement of the power supply apparatus which concerns on the same as the above. It is a figure explaining operation | movement of the solar cell connected to the PV converter which concerns on the same as the above. It is a figure explaining operation | movement of the solar cell connected to the PV converter which concerns on the same as the above. It is a figure which shows the input voltage-output voltage characteristic of the PV converter which concerns on the same as the above. It is a figure which shows the input voltage-output voltage characteristic of the PV converter which concerns on the modification of embodiment of this invention.

  Although the form demonstrated below assumes and demonstrates the house of a detached house as a building which applies this invention, it does not prevent applying the technical idea of this invention to an apartment house. As shown in FIG. 2, the house H is provided with a DC power supply unit 101 that outputs DC power and a DC device (load device) 102 as a load driven by the DC power. DC power is supplied to the DC device 102 through a DC supply line Wdc connected to the output end of the DC device 102. A current flowing through the DC supply line Wdc is monitored between the DC power supply unit 101 and the DC device 102. When an abnormality is detected, power is supplied from the DC power supply unit 101 to the DC device 102 on the DC supply line Wdc. A DC breaker 114 is provided for limiting or blocking the current.

  The DC supply line Wdc is used as both a DC power supply path and a communication path, and is connected to the DC supply line Wdc by superimposing a communication signal for transmitting data on a DC voltage using a high-frequency carrier wave. Enables communication between devices. This technique is similar to a power line carrier technique in which a communication signal is superimposed on an AC voltage in a power line that supplies AC power.

  The DC supply line Wdc is connected to the home server 116 via the DC power supply unit 101. The home server 116 is a main device that constructs a home communication network (hereinafter referred to as “home network”), and communicates with a subsystem or the like constructed by the DC device 102 in the home network.

  In the example shown in the drawing, as an subsystem, an illumination system comprising an information equipment system K101 comprising an information-system DC device 102 such as a personal computer, a wireless access point, a router, and an IP telephone, and an illumination system DC equipment 102 such as a lighting fixture. K102, K105, entrance system K103 composed of DC device 102 for dealing with visitors, monitoring intruders, etc., and residential alarm system K104 composed of alarm DC device 102 such as a fire detector. Each subsystem constitutes a self-supporting distributed system, and can operate even with the subsystem alone.

  The above-described DC breaker 114 is provided in association with a subsystem. In the illustrated example, four DCs are associated with the information equipment system K101, the lighting system K102 and the entrance system K103, the house alarm system K104, and the lighting system K105. A breaker 114 is provided. When a plurality of subsystems are associated with one DC breaker 114, a connection box 121 for dividing the system of the DC supply line Wdc is provided for each subsystem. In the illustrated example, a connection box 121 is provided between the illumination system K102 and the entrance system K103.

  As the information equipment system K101, there is provided an information equipment system K101 composed of a DC equipment 102 connected to a DC outlet 131 arranged in advance in the house H (constructed when the house H is constructed) in the form of a wall outlet or a floor outlet.

  The lighting systems K102 and K105 include a lighting system K102 composed of a lighting device (DC device 102) arranged in advance in the house H and a lighting device (DC device 102) connected to a hook ceiling 132 arranged in advance on the ceiling. An illumination system K105 is provided. At the time of interior construction of the house H, the contractor attaches the lighting fixture to the hook ceiling 132, or the householder himself attaches the lighting fixture.

  In addition to using an infrared remote control device, a control instruction for the lighting apparatus that is the DC device 102 constituting the lighting system K102 can be given using a communication signal from the switch 141 connected to the DC supply line Wdc. In addition to using an infrared remote control device, a control instruction for the luminaire that is the DC device 102 constituting the illumination system K105 can be given using a communication signal from the switch 142 connected to the DC supply line Wdc. That is, the switches 141 and 142 have a communication function together with the DC device 102. In addition, a control instruction may be given by a communication signal from another DC device 102 in the home network or the home server 116 regardless of the operation of the switches 141 and 142. The instructions to the lighting fixture include lighting, extinguishing, dimming, and blinking lighting.

  Since any DC device 102 can be connected to the DC outlet 131 and the hooking ceiling 132 described above and DC power is output to the connected DC device 102, the DC outlet 131 and the hooking ceiling 132 are distinguished below. When it is not necessary, it is called “DC outlet”.

  These DC outlets have a plug-in connection port into which a contact (not shown) provided directly on the DC device 102 or a contact (not shown) provided via a connection line is inserted into the body. The contact receiver that directly contacts the contact inserted into the connection port is held by the container. That is, the direct current outlet supplies power in a contact manner. When the DC device 102 connected to the DC outlet has a communication function, a communication signal can be transmitted through the DC supply line Wdc. A communication function is provided not only in the DC device 102 but also in the DC outlet.

  The home server 116 not only is connected to the home network, but also has a connection port connected to the wide area network NT that constructs the Internet. When the in-home server 116 is connected to the wide area network NT, it is possible to receive services from the center server 200 that is a computer server connected to the wide area network NT.

  The service provided by the center server 200 includes a service that enables monitoring and control of equipment (including mainly the DC equipment 102 but also other equipment having a communication function) connected to the home network through the wide area network NT. is there. This service makes it possible to monitor and control devices connected to the home network using a communication terminal (not shown) having a browser function such as a personal computer, Internet TV, or mobile phone.

  The in-home server 116 has both functions of communication with the center server 200 connected to the wide area network NT and communication with equipment connected to the home network, and identification information about equipment in the home network ( Here, it is assumed that an IP address is used).

  The home server 116 enables monitoring and control of home devices through the center server 200 from a communication terminal connected to the wide area network NT by using a communication function with the center server 200. The center server 200 mediates between home devices and communication terminals on the wide area network NT.

  When monitoring and controlling home devices from a communication terminal, monitoring and control requests are stored in the center server 200, and the home device periodically performs one-way polling communication to monitor from the communication terminal. And receive control requests. With this operation, it is possible to monitor and control devices in the house from the communication terminal.

  Further, when an event that should be notified to the communication terminal, such as a fire detection, occurs in the home device, the home device notifies the center server 200, and the center server 200 notifies the communication terminal by e-mail.

  An important function among the communication functions with the home network in the home server 116 is the detection and management of the devices constituting the home network. The home server 116 automatically detects devices connected to the home network by applying UPnP (Universal Plug and Play). The home server 116 includes a display device 117 having a browser function, and displays a list of detected devices on the display device 117. The display device 117 has a configuration with a touch panel type or an operation unit, and can perform an operation of selecting desired contents from options displayed on the screen of the display device 117. Therefore, the user (contractor or householder) of the home server 116 can monitor or control the device on the screen of the display device 117. The display device 117 may be provided separately from the home server 116.

  The in-home server 116 manages information related to device connection, and grasps the type, function, and address of the device connected to the home network. Accordingly, the devices in the home network can be operated in conjunction with each other. Information on the connection of the device is automatically detected as described above. In order to operate the device in an interlocking manner, the device itself is automatically associated with the attribute held by the device itself, and the home server 116 is configured as a personal computer. It is also possible to connect various information terminals and use the browser function of the information terminals to associate devices.

  Each device holds the relationship of the interlocking operation of the devices. Therefore, the device can operate in an interlocked manner without passing through the home server 116. By associating the linked operations for each device, for example, by operating a switch that is a device, it is possible to turn on or off the lighting fixture that is the device. In many cases, the association of the interlocking operations is performed within the subsystem, but the association beyond the subsystem is also possible.

  Incidentally, the DC power supply unit 101 basically generates DC power by power conversion of the commercial power supply AC supplied from outside the house. In the configuration shown in the figure, the commercial power source AC is input to the AC / DC converter 112 including the switching power source through the main breaker 111 attached to the distribution board 110 as an internal unit. The DC power output from the AC / DC converter 112 is connected to each DC breaker 114 through the cooperative control unit 113.

  The DC power supply unit 101 is provided with a secondary battery 162 in preparation for a period in which power is not supplied from the commercial power source AC (for example, a power failure period of the commercial power source AC). As the secondary battery 162, for example, a lithium ion secondary battery or the like is used. It is also possible to use a solar cell 161 or a fuel cell 163 that generates DC power. The solar cell 161, the secondary battery 162, and the fuel cell 163 are distributed power sources with respect to the main power source including the AC / DC converter 112 that generates DC power from the commercial power source AC. Although not shown, the secondary battery 162 includes a circuit unit that controls charging.

  As shown in FIG. 10, the solar cell 161 has a characteristic that the output current gradually decreases from the short-circuit current Isc as the output voltage increases, and the output power becomes maximum at a certain output voltage. The output voltage when the maximum power Pm is reached is the optimum voltage Vm.

  The secondary battery 162 shown in FIG. 2 is charged in a timely manner by the commercial power source AC, the solar cell 161, and the fuel cell 163, and the secondary battery 162 is discharged not only during the period when power is not supplied from the commercial power source AC but also as necessary. Done in a timely manner. The coordination control unit 113 performs charge / discharge of the secondary battery 162 and coordination between the main power source and the distributed power source. That is, the cooperative control unit 113 functions as a DC power control unit that controls the distribution of power from the main power source and the distributed power source constituting the DC power supply unit 101 to the DC device 102.

  Since the driving voltage of the DC device 102 is selected from a plurality of types of voltages depending on the device, a DC / DC converter is provided in the cooperative control unit 113 to convert the DC voltage obtained from the main power source and the distributed power source into a necessary voltage. Is desirable. Normally, one type of voltage is supplied to one subsystem (or DC device 102 connected to one DC breaker 114), but three or more wires are used for one subsystem. A plurality of types of voltages may be supplied. It is also possible to adopt a configuration in which the DC supply line Wdc is of a two-wire type and the voltage applied between the lines is changed over time. The DC / DC converter may be provided in a plurality of dispersed manners like the DC breaker.

  In the above configuration example, only one AC / DC converter 112 is illustrated, but a plurality of AC / DC converters 112 can be arranged in parallel, and when a plurality of AC / DC converters 112 are provided. It is desirable to increase or decrease the number of AC / DC converters 112 that are operated according to the magnitude of the load.

  The AC / DC converter 112, the cooperative control unit 113, the DC breaker 114, the solar cell 161, the secondary battery 162, and the fuel cell 163 described above are provided with a communication function, and include a main power source, a distributed power source, and a DC device 102. It is possible to perform cooperative operations that deal with the load status. The communication signal used for this communication is transmitted in the form of being superimposed on the DC voltage in the same manner as the communication signal used for the DC device 102.

  In the above example, the AC / DC converter 112 is arranged in the distribution board 110 in order to convert the AC power output from the main breaker 111 into DC power by the AC / DC converter 112. On the output side, a branch breaker (not shown) provided in the distribution board 110 branches the AC supply line into a plurality of systems, and an AC / DC converter is provided on the AC supply line of each system to convert it into DC power for each system. You may employ | adopt the structure to do.

  In this case, since the DC power supply unit 101 can be provided for each floor or room of the house H, the DC power supply unit 101 can be managed for each system, and the DC device 102 that uses DC power and Since the distance of the DC supply line Wdc between the two is reduced, the power loss due to the voltage drop in the DC supply line Wdc can be reduced. Also, the main breaker 111 and the branch breaker are housed in the distribution board 110, and the AC / DC converter 112, the cooperative control unit 113, the DC breaker 114, and the home server 116 are housed in a separate board from the distribution board 110. Also good.

  Next, the power supply device 3 housed in the DC power supply unit 101 will be described with reference to FIG. The power supply device 3 includes a plurality of (four in the illustrated example) power supply devices 4 (5, 6) that operate in parallel and supply DC power to the DC device (load device) 102, and the entire DC power supply system. And a monitoring device 7 for monitoring.

  The plurality of power supply devices 4 includes a first power supply device 5 and a plurality (three in the illustrated example) of second power supply devices 6 (6a to 6c).

  The first power supply device 5 is a constant voltage power supply device that uses a DC voltage that is always a constant voltage regardless of the magnitude of the output current Io1 as an output voltage Vo1 (see FIG. 5B). A power supply voltage from the commercial power supply AC is input to the first power supply device 5 as the input voltage Vi1 (see FIG. 3). That is, the first power supply device 5 is a power supply device for commercial power supply that supplies DC power to the DC device 102 using the commercial power supply AC as an input power supply.

  As shown in FIG. 3, the first power supply device 5 has an on-duty width set according to the voltage detection means 50 for detecting the output voltage Vo1, the reference voltage V2, and the detection voltage V1 of the voltage detection means 50. A switching control means 51 for generating the pulse width modulation signal S1 and a DC / DC converter 52 having a switching element 520 that is turned on and off according to the on-duty width of the pulse width modulation signal S1 from the switching control means 51. Yes.

  The voltage detection means 50 includes two resistors 500 and 501 connected in series and a voltage follower 502 to which a divided voltage by the resistors 500 and 501 is input, and the output voltage Vo1 of the first power supply device 5 is Detect the size.

  The switching control unit 51 includes a switching IC 510 to which the detection voltage (output voltage of the voltage follower 502) V1 and the reference voltage V2 of the voltage detection unit 50 are input.

  The switching IC 510 outputs a pulse width modulation signal S1 in which the on-duty width is set so that the differential voltage (V2-V1) between the reference voltage V2 and the detection voltage V1 is constant, to the switching element 520. That is, the switching IC 510 sets the on-duty width of the pulse width modulation signal S1 so that the output voltage Vo1 (detection voltage V1) is always constant.

  The DC / DC converter 52 includes a smoothing capacitor 521, an inductor 522, a switching element 520, a diode 523, and a smoothing capacitor 524 in order from the input side. The DC / DC converter 52 receives the input voltage Vi1 by the on / off operation of the switching element 520. Boost the pressure.

  The switching element 520 is, for example, a field effect transistor, and the pulse width modulation signal S1 from the switching IC 510 is input to the gate via the resistor 525. When the switching element 520 is turned on, conduction occurs between the source and the drain, and electromagnetic energy is stored in the inductor 522. Thereafter, when the switching element 520 is turned off, the electromagnetic energy stored in the inductor 522 is released and the voltage is increased. The boosted voltage is smoothed by the smoothing capacitor 524. The DC voltage smoothed by the smoothing capacitor 524 is output to the DC device 102 (see FIG. 1) as the output voltage Vo1.

  By the above operation, the first power supply device 5 deviates from the output current-output voltage characteristic in which the output voltage Vo1 is a constant DC voltage regardless of the magnitude of the output current Io1, as shown in FIG. 5B. Feedback control can be performed so that there is no.

  As shown in FIG. 1, a solar cell 161 is connected to the second power supply device 6a, a secondary battery 162 is connected to the second power supply device 6b, and a fuel cell 163 is connected to the second power supply device 6c. It is connected. These second power supply devices 6a to 6c receive the input voltage Vi2 (see FIGS. 4 and 8) from the batteries 161 to 163 connected thereto, respectively. That is, the second power supply device 6a is a solar cell power supply device (PV converter) that supplies the DC power to the DC device 102 using the solar cell 161 as an input power supply, and the second power supply device 6b is a secondary battery 162. Is a secondary battery power supply device (BAT converter) that supplies DC power to the DC device 102 as an input power source, and the second power supply device 6c supplies DC power to the DC device 102 using the fuel cell 163 as an input power source. This is a power supply device (FC converter) for a fuel cell.

  As shown in FIG. 5A, the BAT converter 6b and the FC converter 6c (hereinafter referred to as “second power supply devices 6b and 6c”) have a direct current that decreases monotonously as the output currents Iob and Ioc (Io2) increase. The voltages are output voltages Vob and Voc (Vo2). Such output current-output voltage characteristics of the second power supply devices 6b and 6c can be expressed as Vo2 = −αIo2 + V0 (α> 0, V0> 0). In the output current-output voltage characteristic, Vo2 + αIo2 is a constant value at V0. α may be a different value for each of the second power supply devices 6b and 6c, or may be the same value.

  As shown in FIG. 4, each of the second power supply devices 6b and 6c includes a current detection means 60 for detecting the output current Io2, a voltage detection means 61 for detecting the output voltage Vo2, and a detection voltage of the voltage detection means 61. The switching control means 62 for generating the pulse width modulation signal S2 in which the on-duty width is set according to V5 and the voltage V8 output from the current detection means 60, and the ON of the pulse width modulation signal S2 from the switching control means 62 A DC / DC converter 63 having a switching element 630 that performs an on / off operation according to a duty width, and an adjustment unit 64 that adjusts the magnitude of the output current Io2 by control of a control unit 72 (see FIG. 1) described later. .

  The current detection means 60 is divided by resistors 600 and 605, a current IC 601 that detects the voltage across the resistor 600, resistors 602 and 603 that divide the output voltage V3 of the current IC 601, and resistors 602 and 603. And a voltage follower 604 to which the divided voltage is input, and detects the magnitude of the output current Io2.

  The voltage detection unit 61 includes two resistors 610 and 611 connected in series and a voltage follower 612 to which a divided voltage by the resistors 610 and 611 is input, and detects the magnitude of the output voltage Vo2.

  The switching control means 62 includes a switching IC 620 to which the detection voltage (output voltage of the voltage follower 612) V5 of the voltage detection means 61 and the voltage V8 output from the current detection means 60 are input.

  The DC / DC converter 63 includes a smoothing capacitor 631, an inductor 632, a switching element 630, a diode 633, and a smoothing capacitor 634 in order from the input side, and the input voltage Vi <b> 2 is obtained by the on / off operation of the switching element 630. Boost the pressure.

  The adjusting unit 64 includes a CPU 640 that obtains an instruction value of the output current Io2 from a control unit 72 (see FIG. 1) described later, two resistors 641 and 642 that divide the output voltage V6 of the CPU 640, and resistors 641 and 642. And a non-inverting amplifier circuit 643 to which the divided voltage is input.

  In the CPU 640, during operation of the power supply device 3, that is, when power is supplied to the DC device 102 by the power supply device 3, the magnitude of the output current Io2 is varied based on the instruction value from the control unit 72. Control is performed.

Monitoring apparatus shown in FIG. 1 7 includes a load current detection unit 70 for detecting a current value of the load current I _L supplied to the DC device 102, detects a current value of the output current Io1, Io2 of the power device 5, 6 Output current detection unit (output current detection unit) 71 and a control unit (control unit) 72 that controls the operation of the second power supply devices 6a to 6c.

The load current detection unit 70 detects a necessary current from each DC device 102 at a preset time interval while the power supply device 3 is operating, that is, when power is supplied to the DC device 102 by the power supply device 3. Te, detecting the load current I _L is the total used current of the DC device 102 side. The preset time interval is a time interval that satisfies the load following (for example, several milliseconds).

  The output current detection unit 71 detects the output current Io2 of the second power supply device 6 when the output voltage Vo2 of the second power supply device 6 is matched with the output voltage Vo1 of the first power supply device 5, respectively.

  The control unit 72 determines how much power should be supplied from each power source device 5 and 6 to each DC device 102 as a whole system, and adjusts the output of each power source device 5 and 6 accordingly. The control unit 72 transmits an instruction value for instructing the current value of the output current Io2 to each of the adjusting means 64 (see FIG. 4) of the second power supply devices 6b and 6c. The indicated value may be a value that directly represents the current value of the output current Io2, or may be a voltage value obtained by converting the current value of the output current Io2. Each indication value is not limited to a value for indicating the current value of the output current Io2 in the second power supply devices 6b and 6c, and indicates the magnitude of the output power in the second power supply devices 6b and 6c. It may be a value for

  The CPU 640 of the second power supply devices 6b and 6c shown in FIG. 4 outputs an output voltage V6 having a magnitude corresponding to an instruction value from the control unit 72 (see FIG. 1). The output voltage V7 of the non-inverting amplifier circuit 643 increases as the output voltage V6 of the CPU 640 increases, and decreases as the output voltage V6 of the CPU 640 decreases.

  Further, a differential amplifier circuit 606 is inserted between the voltage follower 604 and the resistor 605 in the current detection means 60. The differential amplifier circuit 606 is a voltage V8 (= β) proportional to a differential voltage (V7−V4) between the output voltage V7 of the non-inverting amplifier circuit 643 and the detection voltage of the current detection means 60 (output voltage of the voltage follower 604) V4. (V7−V4) (β> 0)) is output to the switching IC 620. Therefore, even when the detection voltage V4 is the same, when the output voltage V6 and the output voltage V7 increase according to the instruction value from the control unit 72, the voltage V8 output to the switching IC 620 also increases. Conversely, when the output voltage V6 and the output voltage V7 are reduced, the voltage V8 output to the switching IC 620 is also reduced. Note that the magnitude of β is set so that the voltage V8 can be calculated as the detection voltage V5 in the switching IC 620 described later.

  The switching IC 620 outputs the pulse width modulation signal S2 whose on-duty width is set (changed) so that the differential voltage (V8−V5), that is, the voltage (βV7− (V5 + βV4)) between the voltage V8 and the detection voltage V5 is constant. Output to the switching element 630. Specifically, when the voltage (βV7− (V5 + βV4)) becomes larger than before, the switching IC 620 reduces the voltage (βV7− (V5 + βV4)) (voltage (βV7− (V5 + βV4)) until now. The on-duty width of the pulse width modulation signal S2 is set wide. Conversely, when the voltage (βV7− (V5 + βV4)) becomes smaller than before, the switching IC 620 increases the voltage (βV7− (V5 + βV4)) (voltage (βV7− (V5 + βV4)) is the same as before. The on-duty width of the pulse width modulation signal S2 is set to be small.

  The switching element 630 is, for example, a field effect transistor, and the pulse width modulation signal S2 from the switching IC 620 is input to the gate via the resistor 635. When the switching element 630 is turned on, conduction occurs between the source and the drain, and electromagnetic energy is stored in the inductor 632. Thereafter, when the switching element 630 is turned off, the electromagnetic energy stored in the inductor 632 is released to increase the voltage. The boosted voltage is smoothed by the smoothing capacitor 634. The DC voltage smoothed by the smoothing capacitor 634 is output to the DC device 102 (see FIG. 1) as the output voltage Vo2.

  With the above operation, when the output current Io2 (detection voltage V4) becomes larger than before, the voltage (βV7− (V5 + βV4)) becomes smaller than before, but the voltage (βV7− (V5 + βV4)) becomes larger than before. The output voltage Vo2 (detection voltage V5) can be made smaller than before by setting the on-duty width to be the same size and reducing the boost. On the other hand, when the output current Io2 (detection voltage V4) becomes smaller than before, the voltage (βV7− (V5 + βV4)) becomes larger than before, but the voltage (βV7− (V5 + βV4)) has the same magnitude as before. The output voltage Vo2 (detection voltage V5) can be increased more than before by setting the on-duty width to be large and increasing the boost.

  Therefore, the second power supply devices 6b and 6c having such a configuration can maintain the voltage (βV7− (V5 + βV4)) so that the output voltage Io2 increases as shown in FIG. 5A. Feedback control can be performed so that Vo2 does not deviate from the output current-output voltage characteristic (characteristic that Vo2 + αIo2 is a constant value) that monotonously (linearly) decreases.

  When the second power supply devices 6b and 6c having such output current-output voltage characteristics have the intersections used together with the first power supply device 5, the output voltage Vo2 is the output voltage of the first power supply device 5. The output current Io2 is output when the output voltage Vo2 is adjusted to Vo1 and the output voltage Vo2 is adjusted to the output voltage Vo1.

  Here, when the output current Io2 decreases, the output voltage Vo2 fluctuates according to the output current-output voltage characteristic of FIG. 6 and temporarily becomes larger than the constant voltage ((A) of FIG. 6). When the output voltage Vo2 becomes larger than the constant voltage, the output current Io2 becomes large, and as a result, the detection voltage V4 also becomes large ((B) in FIG. 6). When the detection voltage V4 increases, the voltage (βV7− (V5 + βV4)) decreases, so that the on-duty width of the pulse width modulation signal S2 decreases and the output voltage Vo2 (detection voltage V5) decreases ((( C)). As a result, the output voltage Vo2 is adjusted to the output voltage Vo1, and the output current Io2 returns to the original magnitude.

  On the other hand, when the output current Io2 increases, the output voltage Vo2 fluctuates according to the output current-output voltage characteristics of FIG. 6 and temporarily becomes smaller than the constant voltage ((D) of FIG. 6). When the output voltage Vo2 becomes smaller than the constant voltage, the output current Io2 becomes small, and as a result, the detection voltage V4 also becomes small ((E) in FIG. 6). When the detection voltage V4 decreases, the voltage (βV7− (V5 + βV4)) increases, so that the on-duty width of the pulse width modulation signal S2 increases, and the output voltage Vo2 (detection voltage V5) increases (FIG. 6 ( F)). As a result, the output voltage Vo2 is adjusted to the output voltage Vo1, and the output current Io2 returns to the original magnitude.

Subsequently, with respect to such second power supply devices 6b and 6c, the total use current (load current I _L ) on the DC device 102 side becomes large, and the output voltage Vo2 (detection voltage V5) is constant. A case where an instruction value for increasing the output current Io2 is received from the control unit 72 will be described with reference to FIG. First, when there is the indicated value, the output voltage V7 and the voltage V8 (= β (V7−V4)) increase. At this time, since the voltage (βV7− (V5 + βV4)) becomes large, the on-duty width of the pulse width modulation signal S2 becomes wide, and the output voltage Vo2 temporarily becomes larger than the output voltage Vo1 ((A) in FIG. 7). . This operation corresponds to adding a predetermined voltage to the output voltage Vo2 of the second power supply devices 6b and 6c. When the output voltage Vo2 increases, the output current Io2 (detection voltage V4) also increases ((B) in FIG. 7). As the detection voltage V4 increases, the voltage (βV7− (V5 + βV4)) decreases, and the on-duty width of the pulse width modulation signal S2 decreases. As a result, the output voltage Vo2 becomes small ((C) in FIG. 7). After repeating the above operation, the output voltage Vo2 becomes the output voltage Vo1. Thereby, the second power supply devices 6b and 6c are configured so that the output current Io2 at the intersection with the constant voltage characteristic (output current-output voltage characteristic of the first power supply device 5) becomes the indicated value. The output current-output voltage characteristics of 6b and 6c are shifted, and the output current Io2 according to the indicated value is output.

In contrast, the load current I _L decreases, the output voltage Vo2 (the detection voltage V5) is constant under, when an instruction value to reduce the output current Io2 had from the control unit 72, the output voltage V7 and voltage V8 (= β (V7−V4)) becomes smaller. At this time, since the voltage (βV7− (V5 + βV4)) becomes small, the on-duty width of the pulse width modulation signal S2 becomes narrow and the output voltage Vo2 becomes temporarily smaller than the output voltage Vo1 ((D) in FIG. 7). . This operation corresponds to subtracting a predetermined voltage from the output voltage Vo2 of the second power supply devices 6b and 6c. When the output voltage Vo2 decreases, the output current Io2 (detection voltage V4) also decreases ((E) in FIG. 7). As the detection voltage V4 decreases, the voltage (βV7− (V5 + βV4)) increases, and the on-duty width of the pulse width modulation signal S2 increases. As a result, the output voltage Vo2 increases ((F) in FIG. 7). After repeating the above operation, the output voltage Vo2 becomes the output voltage Vo1. Thereby, the second power supply devices 6b and 6c are configured so that the output current Io2 at the intersection with the constant voltage characteristic (output current-output voltage characteristic of the first power supply device 5) becomes the indicated value. The output current-output voltage characteristics of 6b and 6c are shifted, and the output current Io2 according to the indicated value is output.

  Even after the output current-output voltage characteristics of the second power supply devices 6b and 6c are shifted as described above, the output voltage Vo2 is adjusted to the output voltage Vo1 of the first power supply device 5 and output as in the case before the shift. An output current Io2 when the voltage Vo2 is adjusted to the output voltage Vo1 is output.

As described above, when the load current _IL changes, the second power supply devices 6b and 6c shift the output current-output voltage characteristics based on the instruction value from the control unit 72 as shown in FIG. be able to. Even after the shifting, the second power supply devices 6b and 6c have the output voltage Vo2 adjusted to the output voltage Vo1 of the first power supply device 5 and the output voltage Vo2 has the same magnitude as the output voltage Vo1. The output current Io2 can be output to the DC device 102. Thus, even when the load current I _L is varied, with the power supply device 3 may be set to an output current Io2 corresponding second power device 6b, and 6c the load current I _L, the load current I _L Even if it changes, the output voltage Vo2 of the second power supply devices 6b and 6c is adjusted to the output voltage Vo1 of the first power supply device 5, so that the output voltage Vo2 can be kept at a constant voltage. As a result, it is possible to stably supply power to the DC device 102.

  An example is shown below. In FIG. 5, (a) shows the output current-output voltage characteristics of the second power supply devices 6b and 6c, and (b) shows the output current-output voltage characteristics of the first power supply device 5. Here, as shown in FIG. 5 (c), I11 is instructed as an instruction value from the control unit 72, and the output current-output voltage characteristics of the second power supply devices 6b and 6c are indicated by the arrows in FIG. 5 (c). When shifted in this manner, the output current Io2 of the second power supply devices 6b and 6c can be increased from I12 to I11.

  Further, in the second power supply devices 6b and 6c, the relationship in which the output voltage Vo2 decreases monotonously as the output current Io2 increases can be easily realized without increasing the number of parts from the configuration of the first power supply device 5. can do.

Next, the control to the PV converter 6a in the monitoring device 7 shown in FIG. 1 will be described. Control unit 72 of the monitoring device 7 sets the target value of the output current Ioa of the PV converter 6a in response to the detected load current I _L in the load current detection unit 70. Thereafter, the control unit 72 changes the input voltage Via (output voltage of the solar cell 161) of the PV converter 6a so that the output current Ioa of the PV converter 6a detected by the output current detection unit 71 approaches the target value. The instruction is transmitted to the PV converter 6a (adjusting means 64a). When the output current Ioa detected by the output current detection unit 71 reaches the target value, the control unit 72 stops transmitting the instruction to the PV converter 6a (adjustment unit 64a). When starting the operation of the PV converter 6a, the control unit 72 transmits an initial instruction to the PV converter 6a so that the input voltage Via becomes a predetermined voltage value (initial voltage value).

  Next, the configuration of the PV converter 6a will be described with reference to FIG. The PV converter 6a includes a voltage detection means 61 for detecting the output voltage Voa, an input voltage detection means 65 for detecting the input voltage Via (the output voltage of the solar cell 161), a detection voltage V5 of the voltage detection means 61, and an input voltage detection. Switching control means 62 for generating a pulse width modulation signal S2 having an on-duty width set according to the voltage V8a output from the means 65, and according to the on-duty width of the pulse width modulation signal S2 from the switching control means 62 A DC / DC converter 63 having a switching element 630 that is turned on and off, and an adjusting means 64a that adjusts the magnitude of the input voltage Via under the control of the control unit 72 (see FIG. 1). The configurations of the voltage detection means 61, the switching control means 62 and the DC / DC converter 63 are the same as the voltage detection means 61, the switching control means 63 and the DC / DC converter 63 of the second power supply devices 6b and 6c (see FIG. 4). ).

  The input voltage detection means 65 includes two resistors 650 and 651 connected in series, a voltage follower 652 to which a divided voltage by the resistors 650 and 651 is input, and an inverting amplifier circuit 653 to which an output voltage of the voltage follower 652 is input. And the input voltage Via is detected.

  The adjusting means 64a includes a CPU 644 that obtains an instruction (command) from the control unit 72 (see FIG. 1), two resistors 641 and 642 that divide the output voltage V6a of the CPU 644, and a divided voltage by the resistors 641 and 642. An input non-inverting amplifier circuit 643 and a changeover switch 645 are provided.

  In the adjusting unit 64a, the CPU 644 acquires an instruction from the control unit 72. Based on the instruction from the control unit 72, the adjusting unit 64a is configured to increase the output voltage Voa of the PV converter 6a monotonously when the output voltage of the solar cell 161 (the input voltage Via of the PV converter 6a) increases. Shift characteristics.

  The CPU 644 performs control for changing the magnitude of the output voltage Voa based on an instruction from the control unit 72 during operation of the power supply device 3, that is, when power is supplied to the DC device 102 by the power supply device 3. Is done.

  By the way, the optimum voltage Vm, which is the voltage at the maximum output power in the solar cell 161, is ideally detected in real time. However, complicated processing is required to detect the optimum voltage Vm in real time. Therefore, in the present embodiment, the CPU 644 sets a desired ratio of the voltage to the known open circuit voltage Voc to the optimum voltage Vm (= γVoc, 0 <γ <1) (for example, 0.8 of the open circuit voltage Voc). Double (γ = 0.8) is the optimum voltage Vm). When the CPU 644 shifts the input voltage-output voltage characteristic in accordance with an instruction from the control unit 72, the sun when the output voltage Voa of the PV converter 6 a is matched with the output voltage Vo1 of the first power supply device 5. The output voltage of the battery 161 is adjusted in a range (adjustable range) between the optimum voltage Vm and less than the open circuit voltage Voc. The lower limit of the adjustable range may be the optimum voltage Vm or a voltage that is slightly larger than the optimum voltage Vm with a margin. Further, the upper limit of the adjustable range may be the open circuit voltage Voc, or may be a voltage slightly smaller than the open circuit voltage Voc with a margin. That is, the adjustable range can be set as appropriate within the range of the optimum voltage Vm or more and less than the open circuit voltage Voc.

  When the CPU 644 obtains an instruction to increase the input voltage Via from the control unit 72, the CPU 644 decreases the output voltage V6a from the current state. On the other hand, when receiving an instruction to decrease the input voltage Via, the CPU 644 increases the output voltage V6a from the current level. The output voltage V7a of the non-inverting amplifier circuit 643 increases as the output voltage V6a of the CPU 644 increases, and decreases as the output voltage V6a of the CPU 644 decreases.

  In the input voltage detection means 65, a differential amplifier circuit 655 is inserted between the differential amplifier circuit 653 and the resistor 654. The differential amplifier circuit 655 has a voltage V8a (= β (V7a−V9) (β) proportional to a differential voltage (V7a−V9) between the output voltage V7a of the non-inverting amplifier circuit 643 and the output side voltage V9 of the changeover switch 645. > 0)) to the switching IC 620. Therefore, even if the detection voltage V4a (voltage V9) is the same, when the output voltage V6a and the output voltage V7a corresponding to the instruction from the control unit 72 are increased, the voltage V8a output to the switching IC 620 is also increased. Become. Conversely, when the output voltage V6a and the output voltage V7a are reduced, the voltage V8a output to the switching IC 620 is also reduced. Note that the magnitude of β is set so that the voltage V8a can be calculated as the detection voltage V5 in the switching IC 620 described later.

  The function of the switching IC 620 of the PV converter 6a is that the on-duty width is set (changed) so that the differential voltage (V8a−V5), that is, the voltage (βV7a− (V5 + βV9)) between the voltage V8a and the detection voltage V5 is constant. The pulse width modulation signal S2 is output to the switching element 630.

  With the above operation, when the input voltage Via becomes smaller than before, the detection voltage V4a and the voltage V9 become larger than before, and the voltage (βV7a− (V5 + βV9)) becomes smaller than before, but the voltage (βV7a − (V5 + βV9)) is set to the same magnitude as before, the on-duty width of the pulse width modulation signal S2 is set narrow and the step-up is reduced, so that the output voltage Voa (detection voltage V5) is lower than before. Can be small. On the other hand, when the input voltage Via becomes larger than before, the detection voltage V4a and the voltage V9 become smaller than before, and the voltage (βV7a− (V5 + βV9)) becomes larger than before, but the voltage (βV7a− (V5 + βV9). )) To increase the output voltage Voa (detection voltage V5) by increasing the on-duty width of the pulse width modulation signal S2 and increasing the voltage so that it is the same as before. Can do.

  Therefore, the PV converter 6a having such a configuration makes the output voltage Voa monotonous (on a straight line) when the input voltage Via increases as shown in FIG. 9 by making the voltage (βV7a− (V5 + βV9)) constant. Feedback control can be performed so as not to deviate from the output voltage characteristic that increases (characteristic that Voa = αVia + V0).

  In the PV converter 6a having such output voltage characteristics, the output voltage Voa is adjusted to the output voltage Vo1 of the first power supply device 5 in a state having the intersection used together with the first power supply device 5, and the output voltage An output current Ioa when Voa is adjusted to the output voltage Vo1 is output.

  Here, when the input voltage Via (the output voltage of the solar cell 161) increases, the output voltage Voa varies according to the input voltage-output voltage characteristic of FIG. 11 and temporarily becomes larger than the constant voltage (FIG. 11). (A)). When the output voltage Voa becomes larger than the constant voltage, the output current Ioa increases, and as a result, the output power of the solar cell 161 becomes insufficient, and thus the output voltage of the solar cell 161, that is, the output power of the solar cell 161 increases. The input voltage Via becomes small ((B) in FIG. 11). When the input voltage Via is decreased and the detection voltage V4a and the voltage V9 are increased, the voltage (βV7a− (V5 + βV9)) is decreased, whereby the on-duty width of the pulse width modulation signal S2 is decreased, and the output voltage Voa (detection voltage) V5) becomes smaller ((C) in FIG. 11). As a result, the output voltage Voa is adjusted to the output voltage Vo1, and the input voltage Via returns to the original level.

  On the other hand, when the input voltage Via (the output voltage of the solar cell 161) decreases, the output voltage Voa varies according to the input voltage-output voltage characteristics of FIG. 11 and temporarily becomes smaller than the constant voltage (in FIG. 11). (D)). When the output voltage Voa becomes smaller than the constant voltage, the output current Ioa becomes small. As a result, the solar cell 161 is excessively supplied, so that the output voltage of the solar cell 161, that is, the input voltage is reduced so that the output power of the solar cell 161 becomes small. The voltage Via increases ((E) in FIG. 11). When the input voltage Via increases and the detection voltage V4a and the voltage V9 decrease, the voltage (βV7a− (V5 + βV9)) increases to increase the on-duty width of the pulse width modulation signal S2, and the output voltage Voa (detection voltage). V5) becomes larger ((F) in FIG. 10). As a result, the output voltage Voa is adjusted to the output voltage Vo1, and the input voltage Via returns to the original level.

Subsequently, with respect to such a PV converter 6a, the total use current (load current I _L ) on the DC device 102 side is increased, and the input voltage Via (the detection voltage V5) is constant. A case where an instruction to reduce the output voltage of the solar cell 161 is given from the control unit 72 will be described with reference to FIG. First, when the above instruction is issued, the output voltage V7a and the voltage V8a (= β (V7a−V9)) increase. At this time, since the voltage (βV7a− (V5 + βV9)) becomes large, the on-duty width of the pulse width modulation signal S2 becomes wide, and the output voltage Voa becomes temporarily larger than the output voltage Vo1 ((A) in FIG. 12). . This operation corresponds to adding a predetermined voltage to the output voltage Voa of the PV converter 6a. When the output voltage Voa increases, the output current Ioa also increases, and the output power of the PV converter 6a increases. However, if the output voltage Voa increases, the output power of the solar cell 161 increases so that the output power of the solar cell 161 increases. That is, the input voltage Via is reduced ((B) in FIG. 12). When the input voltage Via is decreased and the detection voltage V4a and the voltage V9 are increased, the voltage (βV7a− (V5 + βV9)) is decreased, so that the on-duty width of the pulse width modulation signal S2 is decreased. As a result, the output voltage Voa becomes small ((C) in FIG. 12). After repeating the above operation, the output voltage Voa becomes the output voltage Vo1. As a result, the PV converter 6a has shifted the input voltage-output voltage characteristics of the PV converter 6a so that the input voltage Via decreases in accordance with the instruction, and the input voltage Via, that is, the output voltage of the solar cell 161 as instructed. become.

In contrast, the load current _{I L} decreases, the output voltage Voa (detection voltage V5) is constant under the increasing instruction (output voltage of the solar cell 161) the input voltage Via had from the control unit 72 In this case, the output voltage V7a and the voltage V8a (= β (V7a−V9)) are reduced. At this time, since the voltage (βV7a− (V5 + βV9)) becomes small, the on-duty width of the pulse width modulation signal S2 becomes narrow, and the output voltage Voa becomes temporarily smaller than the output voltage Vo1 ((D) in FIG. 12). . This operation corresponds to subtracting a predetermined voltage from the output voltage Voa of the PV converter 6a. When the output voltage Voa is decreased, the output current Ioa is also decreased, and the output power of the PV converter 6a is decreased. However, the output voltage of the solar cell 161 is reduced so that the output power of the solar cell 161 is decreased because of excessive supply in this state. That is, the input voltage Via increases ((E) in FIG. 12). When the input voltage Via increases and the detection voltage V4a and the voltage V9 decrease, the voltage (βV7a− (V5 + βV9)) increases, so that the on-duty width of the pulse width modulation signal S2 increases. As a result, the output voltage Voa increases ((F) in FIG. 12). After repeating the above operation, the output voltage Voa becomes the output voltage Vo1. As a result, the PV converter 6a has shifted the input voltage-output voltage characteristic of the PV converter 6a so that the input voltage Via increases as instructed, and the input voltage Via, that is, the output voltage of the solar cell 161, as instructed. Become.

From the above, when the load current I _L is changed, the PV converter 6a, based on an instruction from the control unit 72, as shown in FIG. 12, the output voltage Voa is the output voltage Vo1 of the first power device 5 The input voltage-output voltage characteristic can be shifted so that the output current Ioa when adjusted is close to the target value. Even after shifting, the power supply device 3 can maintain the output voltage Voa at a constant voltage by adjusting the output voltage Voa of the PV converter 6a to the output voltage Vo1 of the first power supply device 5. . As a result, it is possible to stably supply power to the DC device 102.

  Further, in the PV converter 6a, the relationship in which the output voltage Voa increases monotonously as the input voltage Via increases can be easily realized from the configuration of the first power supply device 5 with almost no increase in the number of parts.

By the way, as shown in FIG. 16, the adjusting means 64a of the PV converter 6a can set the upper limit value of the output voltage Voa of the PV converter 6a in the input voltage-output voltage characteristic. The changeover switch 645 shown in FIG. 8 switches the voltage V9 input to the differential amplifier circuit 655 under the control of the CPU 644. When the changeover switch 645 is switched from the ground side to the differential amplifier circuit 653 side, the voltage V9 becomes the detection voltage V4a indicating the voltage value of the input voltage Via, and as a result, the input voltage-output voltage characteristic of the PV converter 6a is , Switching to the first characteristic L1 shown in FIG. On the other hand, when the changeover switch 645 is switched from the differential amplifier circuit 653 side to the ground side, the voltage V9 is always constant regardless of the magnitude of the input voltage Via, and therefore the input voltage-output voltage characteristic of the PV converter 6a is It switches to the second characteristic L2 shown in FIG. The CPU 644 acquires the detection result of the voltage detection means 61, and controls the changeover switch 645 to be on the differential amplifier circuit 653 side when the output voltage Voa is smaller than a preset threshold voltage V ′. On the other hand, when the output voltage Voa reaches the threshold voltage V ′, the CPU 644 controls to switch the changeover switch 645 from the differential amplifier circuit 653 side to the ground side. Furthermore, the output voltage Voa of the second characteristic L2 is slightly higher than the output voltage Vo1 of the first power supply device 5. The more, the load current I _L decreases, even if the output current Ioa becomes smaller, it is possible to suppress a little voltage rise.

  As shown in FIG. 8, the temperature detection means 8 for detecting the temperature of the solar cell 161 is connected to the CPU 644. The temperature detection means 8 includes a temperature sensing element 80 whose resistance value varies depending on the temperature of the solar cell 161, and a resistor 81 connected in series to the temperature sensing element 80. The detection voltage V <b> 10 is input to the CPU 644 as the detection result of the temperature detection means 8, that is, the temperature information of the solar cell 161. The CPU 644 corrects the output voltage V6a according to the voltage value of the detection voltage V10. That is, the CPU 644 corrects the shift amount of the input voltage-output voltage characteristic of the PV converter 6a according to the detection result of the temperature detection means 8.

Next, operations related to the PV converter 6a in the power supply device 3 according to the present embodiment will be described with reference to FIG. First, the load current detection unit 70 of the monitoring device 7 detects the current value I0 of the load current _{I L} (S1 in FIG. 13). At this time, the target value of the output current Ioa of the PV converter 6a is set (S2). Subsequently, the control unit 72 transmits an initial instruction for starting the operation of the PV converter 6a to the PV converter 6a (S3). When receiving the first instruction from the controller 72, the CPU 644 of the adjusting unit 64a sets the input voltage Via (the output voltage of the solar cell 161) to the initial voltage value Vp corresponding to the instruction (S4). Thereafter, the adjusting means 64a is configured to input voltage-output of the PV converter 6a so that the output voltage Voa of the PV converter 6a becomes the constant voltage Vo1 when the input voltage Via (output voltage of the solar cell 161) is the initial voltage value Vp. The voltage characteristic is shifted (S5). A current is output from the PV converter 6a (S6). Thereafter, the control unit 72 detects whether or not the output current Ioa is a target value using the detection result of the output current detection unit 71 (S7). When the output current Ioa is smaller than the target value, if the input voltage Via can be changed (S8), the control unit 72 instructs the CPU 644 to make the input voltage Via (the output voltage of the solar cell 161) smaller than the current state. Send. On the other hand, when the output current Ioa is larger than the target value based on the detection result of the output current detection unit 71, the control unit 72 transmits an instruction for increasing the input voltage Via (the output voltage of the solar cell 161) to the CPU 644. To do. The input voltage Via is changed in the PV converter 6a (S9). Even in the case described above, when the output current Ioa does not reach the target value, the difference between the target value and the current current value is the current output from the first power supply device 5, the BAT converter 6b, and the FC converter 6c. Supplement (S10).

Solar power supply device 3, by performing the operation from step S1 to step S10 to periodically (preset time interval), the magnitude of the load current I _L even when the variation corresponding to the variation The output voltage of the battery 161 can be set. The preset time interval is a time interval that satisfies the load following (for example, several milliseconds). Note that the power supply device 3 may perform the operations from step S1 to step S10 other than a preset time interval.

  Next, in the power supply device 3 according to the present embodiment, the output after setting the output voltage of the solar cell 161 to the voltage value Vp will be described with reference to FIG. Here, since the output power of the solar cell 161 is smaller than the load power and the solar cell 161 alone is insufficient, a case where the shortage is supplemented by the commercial power source AC will be described.

  First, when the supply capacity of the solar cell 161 is large as shown in (1) of FIG. 14, the output power W1 of the solar cell 161 is equal to the output power of the PV converter 6a, and is (constant voltage value Vo1) × (PV converter 6a). Current value I1) of the output current Ioa. Thereafter, when the supply capacity of the solar cell 161 decreases as shown in FIG. 14 (2), the output current Ioa decreases as it is. However, since the input voltage Via (the output voltage of the solar cell 161) is already the lower limit value, it is not possible to transmit an instruction. The output power W2 of the solar cell 161 is (constant voltage value Vo1) × (current value I2 of the output current Ioa), and the output current Ioa of the PV converter 6a decreases from I1 to I2. Since the output voltage Vp of the solar cell 161 remains set between the optimum voltage Vm and the open circuit voltage Voc, the output of the solar cell 161 does not go down. Thereafter, when the supply capacity of the solar cell 161 is further reduced as in (3) of FIG. 14, the output power W3 of the solar cell 161 is (constant voltage value Vo1) × (current value I3 of the output current Ioa), The output current Ioa of the PV converter 6a is further reduced. Since the output voltage Vp of the solar cell 161 remains set between the optimum voltage Vm and the open circuit voltage Voc, the output of the solar cell 161 does not go down.

  Note that the case where the supply capacity of the solar cell 161 increases as in (3) → (2) → (1) in FIG. 14 is the same as described above, and the output voltage Vp of the solar cell 161 is the optimum voltage. Since it is still set between Vm and the open circuit voltage Voc, the solar cell 161 does not output down.

  Next, a case where the output power of the solar cell 161 is larger than the load power and the load power is all covered by the solar cell 161 will be described with reference to FIG. The output voltage of the solar cell 161 is initially set to the voltage value Vp1.

  First, when the supply capacity of the solar cell 161 is large as shown in (1) of FIG. 15, the output power W0 of the solar cell 161 is (constant voltage Vo1) × (current value I1 of the output current Ioa of the PV converter 6a). Become. Thereafter, when the supply capacity of the solar cell 161 decreases as in (2) of FIG. 15, the output current Ioa becomes small as it is (the output voltage of the solar cell 161 remains Vp2). An instruction for reducing voltage Via (output voltage of solar cell 161) is transmitted to PV converter 6a. The CPU 644 of the PV converter 6a decreases the output voltage of the solar cell 161 from Vp1 to Vp2, and makes the output power of the solar cell 161 constant at W0. Thereby, even if the supply capability of the solar cell 161 decreases, the output power of the solar cell 161 becomes constant, and as a result, the output current Ioa also becomes constant. Thereafter, when the supply capacity of the solar cell 161 further decreases as in (3) of FIG. 15, the output current Ioa decreases as it is, and the control unit 72 sets the input voltage Via (the output voltage of the solar cell 161). An instruction for reducing the size is transmitted to the PV converter 6a. The CPU 644 reduces the output voltage of the solar cell 161 from Vp2 to Vp3, and makes the output power of the solar cell 161 constant at W0. Thereby, even if the supply capability of the solar cell 161 decreases, the output power of the solar cell 161 becomes constant, and as a result, the output current Ioa also becomes constant. Thereafter, when the supply capacity of the solar cell 161 is further reduced as shown in FIG. 15 (4), the output current Ioa is reduced as it is. However, since the input voltage Via (the output voltage of the solar battery 161) is a lower limit value, it is not possible to transmit an instruction. Therefore, since the output power of the solar cell 161 becomes smaller than the load power, the output power W4 of the solar cell 161 becomes smaller than W0, and as a result, the output current Ioa of the PV converter 6a also becomes smaller. In this case, the shortage of load power is supplemented by the commercial power supply AC. In the above-described operation, the output voltages Vp1, Vp2, and Vp3 of the solar cell 161 are set between the optimum voltage Vm and the open voltage Voc, so that the output of the solar cell 161 is not reduced.

  The case where the supply capacity of the solar cell 161 is increased as in (4) → (3) → (2) → (1) in FIG. 15 is the same as described above, and the output voltage of the solar cell 161 is the same. Is set between the optimum voltage Vm and the open circuit voltage Voc, so that the output of the solar cell 161 does not go down.

  As described above, according to the present embodiment, since the output voltage of the solar cell 161 is always larger than the voltage at which the maximum output power is obtained, it is possible to output current from the PV converter 6a while preventing the output of the solar cell 161 from being reduced. The remaining necessary power can be supplied from the first power supply device 5, the BAT converter 6b, and the FC converter 6c.

Further, according to this embodiment, by the upper limit value of the output voltage Voa of the PV converter 6a is set, when the load current I _L changes suddenly, the output voltage Voa is temporarily in PV converter 6a The increasing amount can be suppressed.

  Furthermore, according to this embodiment, since the influence of the temperature characteristic of the solar cell 161 can be reduced, the operation of the PV converter 6a can be stabilized even if the temperature of the solar cell 161 varies.

  Further, according to the present embodiment, when the output current Ioa of the PV converter 6a detected by the output current detection unit 71 reaches the target value, the control unit 72 stops transmitting the instruction to the PV converter 6a. Therefore, useless control can be eliminated.

  In the present embodiment, the input voltage-output voltage characteristic of the PV converter 6a is shifted as shown in FIG. 9, but the input voltage-output voltage characteristic of the PV converter 6a is illustrated as a modification of the present embodiment. It may be changed as shown in FIG.

102 DC equipment (load equipment)
161 Solar cell 3 Power supply device 4 Multiple power supply devices 5 First power supply device (constant voltage power supply device)
6 Second power supply device 6a PV converter (power supply device for solar cell)
64, 64a Adjustment means 7 Monitoring device 71 Output current detection section (output current detection means)
72 Control unit (control means)
8 Temperature detection means

Claims (4)

A constant voltage power supply device that uses a DC voltage as a constant voltage regardless of the magnitude of the output current;
A solar cell power supply device that operates in parallel with the constant voltage power supply device using a solar cell as an input power source and outputs DC power to a load device;
Output current detection means for detecting the output current of the solar cell power supply device when the output voltage of the solar cell power supply device is matched with the output voltage of the constant voltage power supply device;
Control means for setting a target value of the output current of the power supply device for solar cells,
The solar cell power supply device has an adjusting means for shifting output voltage characteristics in which the output voltage of the solar cell power supply device increases monotonously when the output voltage of the solar cell increases,
The control means transmits an instruction for shifting the output voltage characteristic so that the output current detected by the output current detection means approaches the target value, to the adjustment means,
The adjusting means outputs the solar cell when the output voltage of the solar cell power supply device is adjusted to the output voltage of the constant voltage power supply device when shifting the output voltage characteristic according to the instruction. The power supply device, wherein the voltage is adjusted in a range from the voltage at which the solar cell is the maximum output power to the voltage greater than the open circuit voltage.   The power supply device according to claim 1, wherein the adjustment unit sets an upper limit value of the output voltage of the solar cell power supply device in the output voltage characteristic. Temperature detecting means for detecting the temperature of the solar cell,
The power supply apparatus according to claim 1, wherein the adjustment unit corrects a shift amount of the output voltage characteristic according to a detection result of the temperature detection unit.   The said control means stops transmission of the said instruction | indication to the said adjustment means, when the said output current detected by the said output current detection means becomes the said target value. The power supply device according to claim 1.

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