JP2009112188A - Power supply apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply apparatus which can be connected easily and quickly to a plurality of power supply apparatuses in a simple structure without requiring complicated external wiring to supply power stably. <P>SOLUTION: The power supply apparatus 100 includes a connection switching unit 150 which, when another power supply apparatus is connected to the upstream side of the power supply apparatus 100, disconnects an input plug 120 from a charger 140 and connects the input plug 120 to an output outlet 126, a current measuring unit 152 which measures a current passing through the output outlet 126, a proportionally divided current leading unit 154 which leads a current given by proportionally dividing a current Isum measured from a ratio between a total power capacity Pref of all power supply apparatuses connected to the upstream side and the power supply apparatus 100 and the power capacity Pind of the power supply apparatus 100 alone, and a current control unit 156 which carries out control to turn an output current Iind from an inverter 142 into a proportionally divided current Iind'. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device that can store power in a secondary battery in advance and supply power alone to a connected load.

  The power supply from the power supply system including the power plant may be temporarily interrupted due to a power failure or the like. On the other hand, electric power such as air conditioners and refrigerators must be continuously supplied even during such power outages. In this case, the plug connected to the outlet can be connected to an external power source such as a portable power source capable of supplying power independently of the indoor wiring. Some of such external power sources use fuel cells or secondary batteries. Some examples of fuel cells can generate electric power of several hundred watts or more using hydrogen as a fuel (see, for example, Patent Document 1).

  The power capacity to be supplied by the power supply device differs depending on the load of the electrical equipment to be connected, and must be able to withstand sudden consumption such as inrush current. However, it is not practical to prepare a plurality of types of power supply devices having different power capacities so as to be able to handle any load because it is too expensive to purchase and transport. Therefore, a technique for supplying electric power to an electric device by connecting a plurality of power sources by a master-slave system or by connecting an appropriate number of a plurality of power supply devices having the same power capacity according to the load (for example, Patent Documents) 2 and 3) are known.

  FIG. 10 is a block diagram illustrating an example of supplying power from a plurality of power supply apparatuses to one load. Here, the outputs of the plurality of power supply devices 10 are connected in parallel and connected to the load 12. In the power supply device 10, a secondary battery 14 in which electric power is stored is provided. The DC power of the secondary battery 14 is converted into AC power through the inverter 16 and supplied to the load 12.

  At this time, the current control unit 18 of each power supply device 10 adjusts the AC power generated by the current control unit 18 to the AC power of the other power supply device 10 through voltage control and phase control to the inverter 16 to suppress the generation of the cross current. . In the current control unit 18, the total current Isum to the load measured by the total current measurement unit 20 is divided by the number of connected power supply devices 10, and the output current Iind of the inverter itself measured by the current measurement unit 22. Are compared, and the voltage and phase of the inverter 16 are adjusted so that the deviation becomes 0 (zero). With such a technique, the output current of the inverter 16 of each power supply device 10 can be balanced, and the fluctuation of the nonlinear load can be followed.

  FIG. 11 is a block diagram illustrating another example of supplying power from a plurality of power supply apparatuses to one load. Here, as in FIG. 10, the outputs of the plurality of power supply apparatuses 10 are connected in parallel and connected to the load 12. In the power supply device 10, a secondary battery 14 in which electric power is stored is provided. The DC power of the secondary battery 14 is converted into AC power through the inverter 16 and supplied to the load 12.

In the example of FIG. 11, the current comparison target is different from the example of FIG. 10, and in the case of the example of FIG. 11, the power control unit 30 is adjacent to the output current Iind measured by its own current measurement unit 22. The output current Iind measured by the current measuring unit 22 of the device 10 is compared, and the voltage and phase of the inverter 16 are adjusted so that the deviation becomes zero. Here, all the power supply devices 10 connected in parallel share power with at least the adjacent power supply device 10, and as a result, power can be supplied uniformly from each power supply device 10. In such a technique, even if one of the power supply devices 10 is disconnected, the apportioning amount of power is automatically calibrated and power supply to the load can be continued.
JP 2004-319367 A JP-A-8-223808 JP 2002-262577 A

  However, in the master-slave parallel connection, for example, a master power supply device must be set, which lacks versatility and expandability. Further, in the example of FIG. 10 described above, in order to appropriately perform the current comparison by the current control unit 18, the number of power supply devices 10 to be connected is grasped in advance, and the current from the total current measurement unit 20 is accurately determined by the number. I had to set it to apportion and spent time preparing. Further, every time the number of units to be connected is changed, the internal settings must be updated, which causes a problem from the viewpoint of certainty and safety.

  Furthermore, in the example of FIG. 10, it is necessary to provide a total current measurement unit 20, feed back the total current amount from the total current measurement unit 20 to each power supply device 10, and share the information among all the power supply devices 10. For this reason, wiring and the like are complicated, resulting in an increase in cost and a decrease in reliability.

  Further, in the example of FIG. 11, it is not necessary to grasp the number of power supply devices 10, and power supply can be continued even if one of the power supply devices 10 is disconnected, but the power supply device when the configuration of the power supply device 10 is changed. The connection change between 10 was complicated, and it took time to prepare.

  Furthermore, since all the above-described conventional technologies are based on the premise that the power capacities of the power supply devices 10 to be connected are equal, it is impossible to connect other types of power supply devices even when the power capacity is insufficient. He also had problems.

  The present invention has been made in view of the above-described problems of the conventional power supply apparatus, and an object of the present invention is to easily and quickly provide a plurality of power supply apparatuses with a simple configuration without requiring complicated external wiring. It is an object of the present invention to provide a power supply device that can be connected and can stably supply power.

  In order to solve the above problems, according to an aspect of the present invention, a secondary battery, an inverter that converts DC power from the secondary battery into AC power, and an output that functions as an output terminal of the converted AC power While connected to an outlet and an output outlet, and connecting the power supply to another power supply, an input plug that conducts AC power from the upstream to the output outlet and a current measurement that measures the current passing through the output outlet And an allotted current deriving unit for deriving a current obtained by apportioning the current measured by the ratio of the total power capacity of the power supply unit and the single power capacity of the power supply unit only. And a current control unit that controls the output current from the inverter to be an apportioned current. A power supply apparatus is provided. In this specification, “downstream” indicates the load side when the power supply devices are connected, and “upstream” indicates the opposite side. Therefore, electric power is supplied from the upstream toward the downstream, and the magnitude of the electric power is accumulated as it decreases downstream. The “single power capacity” refers to the power capacity of the corresponding power supply unit alone. Here, the power supply devices are connected in series, but the power is internally connected in parallel.

  The present invention internally distributes the current passing through its output outlet by the ratio of the total power capacity and the single power capacity, so that the output current of the inverter can be controlled in a self-contained manner within the power supply device. Can do. Therefore, it is possible to easily and quickly increase the power supply with a simple configuration and operation such as simply connecting a plurality of power supply devices in series without requiring complicated external wiring.

  In addition, the power supply device converts the AC power input from the input plug into DC power, and exclusively connects and switches the charger that charges the secondary battery, the input plug, and the charger or the outlet. And may be further provided.

  In this way, by using the input plug for both the charging of the secondary battery and the connection of the power supply device, it is necessary to use a separate special configuration for connecting the power supply device in the power supply device having the input plug in advance for charging. In addition, the charging mode and the power supply device connection mode can be switched through the switching by the connection switching unit without significantly changing the main circuit originally provided in the power supply device.

  Here, the total power capacity is derived by a power adding unit that adds the single power capacity of the power supply apparatus to the power capacity of all the power supply apparatuses connected upstream from the connected upstream power supply apparatus. May be.

  In the power supply device of the present invention, the current from the inverter is adjusted by the total power capacity of all power supply devices including itself, and the single power capacity of the power supply device, so that the total power capacity is grasped. There is a need. Here, each power supply device grasps the total power capacity, and transmits the power capacity in a chain through the daisy chain of the power supply devices. Therefore, the downstream power supply device includes itself only by adding its own single power capacity to the power capacity received from one stage upstream without knowing the configuration and the number of all power supply devices to be connected. The total power capacity can be grasped.

  In addition, since the apportioning current deriving unit apportions the current not by the number of power supply devices but by analog quantities such as the actual total power capacity and single power capacity, the power capacities of the connected power supply devices must not be equal. Therefore, it is possible to connect power supply apparatuses having various power capacities.

  The power adding unit may further transmit the derived total power capacity to the connected downstream power supply device.

  With this configuration, the total power capacity up to itself can be transmitted as the upstream power capacity in the downstream power supply apparatus, and the power capacity can be transmitted in a chain.

  When the current is not output from the inverter, the power adding unit may transmit the power capacity received from the power supply device connected upstream to the downstream power supply device as it is.

  Since the power system from the input plug to the output outlet exists independently from the power system of the secondary battery and the inverter, even if the output of one inverter is stopped, the power system from the upstream to the downstream is not interrupted. In addition, the configuration in which the power capacity received from the power device connected to the upstream is transmitted to the downstream as it is can configure the connection of the power devices as if there was no power device having an inverter whose output has been stopped. This will not affect the calculation of the total power capacity at.

  The power capacity of the power supply device may be expressed as a multiple of a predetermined unit power capacity. With this configuration, for example, when 50 W is set to 1, 250 W is set to 5, and the transmission of power capacity from the upstream to the downstream of the power supply device can be expressed by a simple (small) numerical value. The configuration can be simplified. In addition, since the numerical value and the number of bits are small, it is possible to reduce transmission errors and improve reliability.

  When the single power capacities of all the connected power supply devices are substantially equal, the total power capacity is a value obtained by adding 1 to the total number of power supply devices connected upstream from the power supply device one stage upstream. The capacity may be represented by 1.

  With this configuration, as in the multiple described above, it is possible to simplify the transmission of information between the power supply devices. Further, since the received numerical value is the total number of power supply devices that are driven upstream, it is possible to derive the total power capacity and to know how many power supply devices are connected upstream.

  The current control unit may control the voltage and phase of the inverter so that a deviation between reactive power and active power between a current obtained by apportioning the measured current and an output current from the inverter becomes zero.

  With this configuration, it is possible to balance the output current of the inverter of each power supply device, and to follow the fluctuation of the nonlinear load.

  The current control unit may control the voltage of the inverter so that a deviation between a current obtained by apportioning the measured current and an output current from the inverter becomes zero.

  As described above, the output current of the inverter of each power supply device can be balanced by controlling the reactive power and active power deviation between the current apportioned through the output outlet and the output current from the inverter. However, if both the active power and reactive power control are strictly performed, a large processing load is caused depending on the computer. In the present invention, the load current (current passing through the output outlet) and the cross current are allowed to cross due to the phase difference of the voltage, and the load current is balanced while reducing the processing load by controlling only the load current. Is possible.

  The current control unit uses the apportioned current as a target value and an outer loop that uses the output current from the inverter as a controlled variable, and sets the voltage converted value of the difference between the apportioned current and the output current from the inverter as the target value. And an inner loop that uses the voltage of the inverter as a controlled variable.

  By such feedback control of the output current and voltage of the inverter, it becomes possible to supply a more stable output current of the inverter, and the power supply apparatus can share the total current.

  The inner loop may be subjected to PI control. P control (proportional control) functions as a proportional gain in the inner loop, and I control (integral control) absorbs a steady-state deviation over time that cannot be eliminated by P control. With this configuration, since it is not necessary to increase the proportional gain transiently in order to eliminate the steady deviation, stable electric power can be supplied without causing trouble such as vibration.

  The current control unit may include feed forward in the system. With only the feedback control described above, the influence on the inner loop due to the fluctuation of the voltage conversion value becomes large, and the control of the inner loop may be disturbed. The present invention appropriately absorbs the fluctuation of the voltage conversion value by feedforward, and can supply stable power without disturbing the voltage control of the original inverter.

  Transmission / reception of the power capacity between the power supply devices may be performed by a light emitting element and a light receiving element provided in each.

  With this configuration, it is possible to transmit power capacity while maintaining insulation and waterproofing by simply facing the light-emitting element and the light-receiving element without complicated electrical connection. Therefore, it is possible to connect a plurality of power supply devices only by connecting the input plug and the output outlet of the upstream power supply device.

  As described above, according to the present invention, a plurality of power supply devices can be easily and quickly connected with a simple configuration without requiring complicated external wiring, and stable power supply can be achieved.

  Exemplary embodiments of the present invention will be described below in detail with reference to the accompanying drawings. In addition, in this specification and drawing, about the component which has the substantially same function structure, duplication description is abbreviate | omitted by attaching | subjecting the same code | symbol.

(First embodiment)
Even when power supply from a commercial outlet is interrupted due to a power failure or when such an outlet does not exist, power can be supplied independently from the power supply system by using an external power supply such as a portable power supply. It is possible to operate various electric devices by supplying power. In the present embodiment, a power supply device is provided that can secure power capacities corresponding to various electrical devices having different load capacities by easy and quick connection. Here, the case where the power supply device of this embodiment is used alone will be described first, and then the operation when connected will be described.

(Power supply device 100)
FIG. 1 is a perspective view illustrating an appearance of a power supply device 100 according to the first embodiment. In particular, (a) in FIG. 1 shows a front view when the power supply apparatus 100 is placed horizontally, (b) shows a rear view thereof, and (c) shows a front view when placed vertically.

  As shown in FIG. 1A, the power supply device 100 is covered with a casing 110 having an outer dimension of, for example, 300 mm × 300 mm × 100 mm, and contacts the floor surface through the buffer member 112 in a horizontally placed state. Further, a recess 114 for fitting the buffer member 112 of another power supply device 100 is provided on the plane (upper surface) in FIG.

  Further, an input plug 120 for charging the power supply device 100 is provided on the front surface in FIG. 1A, and the input plug 120 is housed in the plug housing groove 124 by the plug housing switch 122. Then, the power charged in the power supply device 100 is supplied to an arbitrary electrical device through the output outlet 126. In the present embodiment, the power capacity of the power supply apparatus 100 is assumed to be approximately 250 W at 100 V AC and 50 Hz.

  As shown in FIG. 1B, the secondary battery 128 that substantially stores electric power in the power supply device 100 is detachably stored in a battery storage groove 130 provided on the back surface of the housing 110 by, for example, a push lock method. When the performance deteriorates due to aging, it can be replaced. Therefore, in this embodiment, the configuration in which the secondary battery 128 is charged by the charger 140 is mainly described. However, only the secondary battery 128 can be removed and charged by a separate charging device. That is, a configuration in which the charger 140 is not provided in the power supply apparatus 100 also belongs to the technical scope of the present embodiment. In this embodiment, a lithium ion battery is used as the secondary battery, but a nickel hydrogen battery, a nickel cadmium battery, or the like may be used, and a fuel battery or other storage battery may be used.

  When the power supply device 100 is transported, it is replaced with a vertical installation as shown in FIG. In addition, a transmission window 134 that transmits light of the light emitting element is provided on the surface provided with the buffer member 112, and a transmission window 136 that transmits light of the light emitting element and transmits it to the light receiving element on the surface provided with the recess 114. It is installed in the position corresponding to the front and back.

  FIG. 2 is an electric block diagram showing a partial function when the power supply apparatus 100 operates alone. Here, in order to facilitate understanding, only functions when the power supply device 100 is used alone are extracted, and other electric circuits in the present embodiment will be described later with reference to FIG.

  In the case of such a rechargeable power supply device 100, the charging is performed by inserting the input plug 120 into the commercial outlet 148 in order to increase the charged amount of the secondary battery 128 in the preparation stage. Here, the charger 140 rectifies, for example, 100V AC power obtained from the commercial outlet 148 into DC power, and controls the charging current to the secondary battery 128 to be an appropriate amount. In this way, when the secondary battery 128 is sufficiently charged, the input plug 120 is removed from the commercial outlet 148, and the power supply apparatus 100 can be used. When using the power supply apparatus 100, the DC power stored in the secondary battery 128 is converted again to AC power by the inverter 142 and supplied to the electrical equipment through the output outlet 126.

  At this time, when the load on the electric device is large and the power capacity of the power supply apparatus 100 is insufficient, a sufficient number of power supply apparatuses 100 are connected to ensure a sufficient power capacity. Hereinafter, a more detailed configuration of the power supply apparatus 100 will be described, and how the power supply apparatus 100 can be connected will be described.

  FIG. 3 is an electrical block diagram showing the overall electrical functions of the power supply apparatus 100 according to the first embodiment. Here, the power supply device 100 includes an input plug 120, a connection switching unit 150, a charger 140, a secondary battery 128, an inverter 142, an output outlet 126, a current measuring unit 152, and a prorated current deriving unit 154. And a current control unit 156 and a power addition unit 158. Of these, the input plug 120, the charger 140, the secondary battery 128, the inverter 142, and the output outlet 126 have already been described with reference to FIGS. 1 and 2, and here, the connection switching unit 150 having a different configuration is used here. The current measuring unit 152, the apportioned current deriving unit 154, the current control unit 156, and the power adding unit 158 will be mainly described.

  The connection switching unit 150 exclusively connects any combination of the input plug 120 and the charger 140 or the input plug 120 and the output outlet 126. When the secondary battery 128 is charged, the input plug 120 and the charger 140 are connected. After the charging is completed, the input plug 120 and the output outlet 126 are connected to connect the power supply device 100. The connection switching may be automatically performed by the connection switching unit 150 detecting the connection destination of the input plug 120, or may be manually performed by the user through a switch or the like.

  As described above, the input plug 120 used for charging is also used for the connection of the power supply device 100, so that it can be understood as compared with FIG. In addition, the charging mode and the power supply unit connection mode can be switched through the switching by the connection switching unit 150 without significantly changing the main circuit originally provided in the power supply unit.

  The current measuring unit 152 is composed of an ammeter such as a current transformer (CT), and the current passing through the output outlet 126, that is, all the power supply devices 100 connected upstream and the power supply. The total current Isum of the device 100 is measured.

  The apportioning current deriving unit 154 includes all the power supply devices 100 connected upstream, the total power capacity Psum of the power supply device 100, and the single power capacity of the power supply device 100 alone (the power capacity of the power supply device 100 alone) Pind. The current Iind ′ obtained by dividing the current measured by the current measuring unit 152 is derived by the ratio of In this way, a part of the total current (current Isum measured by the current measuring unit 152) necessary for the load of the electric equipment, here, the power capacity of itself is covered.

  The current control unit 156 controls the output current Iind from the inverter 142 so as to become the current Iind ′ prorated by the proportional current deriving unit 154.

  At this time, the current control unit 156 causes the inverter so that the reactive power deviation ΔQ and the active power deviation ΔP between the current (total current) Isum passing through the output outlet 126 and the output current Iind from the inverter 142 become zero. The voltage and phase of 142 are controlled.

  That is, the active power of the inverter 142 is adjusted through frequency operation by the PLL 170 and the V / f oscillator 172. The reactive power is adjusted through adjustment of the voltage Vind of the inverter 142, that is, through pulse width modulation by the voltage adjustment unit 174 and the PWM 176. With such a configuration, the output current Iind of the inverter 142 of each power supply apparatus 100 can be balanced, and the fluctuation of the nonlinear load can be tracked. The current control unit 156 is not limited to the circuit configuration described above, and various circuits capable of adjusting the voltage and phase of the output current Iind can be applied.

  As described above, in this embodiment, the current Isum passing through the output outlet 126 of the power supply apparatus 100 is internally divided by the ratio of the total power capacity Psum and the single power capacity Pind. Thus, the output current Iind of the inverter can be controlled in a self-contained manner. Therefore, it is possible to easily and quickly increase the power supply with a simple configuration and operation such as simply connecting a plurality of power supply devices 100 in series without requiring complicated external wiring.

  The power adding unit 158 adds the single power capacity Pind of the power supply apparatus 100 to the power capacities Pref of all the power supply apparatuses 100 connected upstream from the connected power supply apparatus 100 of the upstream one stage. Are added to derive the total power capacity Psum.

  In the power supply device 100 of the present embodiment, as described above, the output current Iind from the inverter 142 includes the total power capacity Psum of all the power supply devices 100 including itself and the single power capacity Pind thereof. Therefore, it is necessary to grasp the total power capacity Psum. Here, each power supply apparatus 100 grasps the total power capacity and transmits the power capacity in a chain through the daisy chain of the power supply apparatus 100. Therefore, the power supply apparatus 100 downstream can simply add its own single power capacity Pind to the power capacity Pref received from one stage upstream without knowing the configuration and number of all the power supply apparatuses 100 to be connected. The total power capacity Psum including itself can be grasped.

  At this time, the apportioning current deriving unit 154 apportions the total current Isum not by the number of power supply devices 100 but by analog quantities such as the actual total power capacity Psum and the single power capacity Pind. The power capacity Pind can also take any numerical value, and there is no restriction that the power capacities of the connected power supply apparatuses 100 should not be equal to each other, and it becomes possible to connect the power supply apparatuses 100 having various power capacities.

  The power adding unit 158 further transmits the derived total power capacity Psum to the connected downstream power supply device 100 through the light emitting element 182. With this configuration, the total power capacity Psum up to itself can be transmitted as the upstream power capacity Pref in the downstream power supply apparatus 100, and the power capacity can be transmitted in a chain manner.

  Further, the transmission of the power capacity Pref between the power supply apparatuses 100 is not limited to the light emitting element 182 and the light receiving element 180 described above, and may be configured by various transmission means such as a wired electric signal or a magnetic signal.

  Here, when current is not output from its own inverter 142, the power adding unit 158 transmits the power capacity Pref received from the power supply apparatus 100 connected upstream to the downstream power supply apparatus as the total power capacity Psum as it is.

  Since the power system from the input plug 120 to the output outlet 126 exists independently of the power system of the secondary battery 128 and the inverter 142, even if the output of one inverter 142 (here, its own inverter) stops, it is upstream The downstream power system is uninterrupted. Further, by connecting the power capacity Pref received from the power supply apparatus 100 connected upstream to the downstream as it is, the connection of the power supply apparatuses 100 is configured as if there was no power supply apparatus 100 having the inverter 142 whose output was stopped. Without affecting the calculation of the total power capacity downstream.

  The power supply device 100 described above configures a connected state of the power supply device 100 by connecting the input plug 120 used for charging to the output outlet 126 of the upstream power supply device 100.

  FIG. 4 is an external perspective view showing an assembly configuration when four power supply devices 100 are connected. Here, the four power supply devices 100a, 100b, 100c, and 100d are connected to each other by connecting their input plugs 120 to the output outlet 126 of the upstream power supply device. Then, the power of the power supply device 100a is accumulated in the downstream side such as the power supply device 100b, the total power in the power supply device 100c, the total power in the power supply device 100d, and the like from the output outlet of the power supply device 100d. The total power is supplied. At this time, the individual power of each power supply apparatus 100 is uniformly consumed by the current apportionment of the present embodiment.

  Further, when the power supply devices 100 are overlapped, the upstream power supply device 100 can be positioned by inserting the upstream buffer member 112 into the downstream recess 114. Here, the case where there are four power supply apparatuses 100 is taken as an example, but it goes without saying that the number is not limited thereto. Here, four power supply apparatuses 100 having the same power capacity are selected. However, as described above, the power capacity of each power supply apparatus 100 can be arbitrarily selected. It will be described below that the present embodiment can be performed even when the power capacities of the power supply apparatuses 100 are different.

  FIG. 5 is an explanatory diagram for explaining current distribution when a plurality of power supply apparatuses 100 having different power capacities are connected. Here, the power supply apparatuses 100a, 100b, 100c, and 100d have power capacities of 250 W, 500 W, 250 W, and 750 W, respectively. Accordingly, the total power capacity Psum by the respective power adding units 158 is sequentially calculated in a daisy chain format, and becomes 250 W, 750 W, 1000 W, and 1750 W from the upstream power supply device 100 a.

  Here, for example, when a current of 7 A is consumed in the terminal load, the current passing through the output outlet 126 of the power supply device 100 d is also 7 A, and the output current Iind of the inverter 142 of the power supply device 100 d is the total power capacity Psum and each Using the single power capacity Pind of the power supply device 100, Isum × Pind / Psum = 7 × 750/1750 = 3A. Similarly, the output current Iind of the inverter 142 of the power supply devices 100c, 100b, and 100a is 1A, 2A, and 1A, and a current corresponding to the power capacity of each power supply device 100 can be output.

  By the way, in the example of FIG. 5, there are three types of power capacity of the power supply device 100, 250 W, 500 W, and 750 W. In this way, when the power supply device 100 can be expressed by a predetermined unit power capacity, here, a multiple of 250 W, 250 W is defined as the radix between the power supply devices 100, and instead of the power capacity itself between the power supply devices 100, The multiple can be transmitted.

  FIG. 6 is an explanatory diagram for explaining another current distribution when a plurality of power supply devices 100 having different power capacities are connected. Here, as in FIG. 5, the power supply apparatuses 100a, 100b, 100c, and 100d have power capacities of 250 W, 500 W, 250 W, and 750 W, respectively. However, since the total power capacity Psum is expressed as a multiple thereof, it is 1, 3, 4, 7 from the upstream. Since its single power capacity Pind is also expressed as a multiple, it becomes 1, 2, 1, 3 from the upstream. Therefore, although the output current Iind of the inverter 142 to be derived is equal to that in FIG. 5, the calculation time of the power adding unit 158 and the proportional current deriving unit 154 is shortened.

  With this configuration, transmission of the power capacity from the upstream side to the downstream side of the power supply apparatus 100 can be represented by only simple (small) numerical values (integers), and the configuration for transmitting information can be simplified. In addition, since the numerical value and the number of bits are small, it is possible to reduce transmission errors and improve reliability. Furthermore, the calculation of the power adding unit 158, the apportioned current deriving unit 154, and the like can be simplified, and it is not necessary to construct an unnecessarily expensive calculation circuit.

  Furthermore, when the single power capacities (power capacities in a single unit) of all the power supply devices 100 to be connected are substantially equal, the total power capacity Psum is received from the power supply device 100 upstream by one stage and is connected to the power supply connected upstream. The single power capacity Pind can be represented by 1 by adding 1 to the total number of devices 100.

  FIG. 7 is an explanatory diagram for explaining another current distribution when a plurality of power supply devices 100 having substantially the same power capacity are connected. Here, unlike FIG. 6, the power supply apparatuses 100 a, 100 b, 100 c, and 100 d are all configured with a power capacity of 250 W, and the single power capacity is represented by 1.

  Also in the configuration of FIG. 7, as in FIG. 6, it is possible to simplify the transmission of information between the power supply devices 100. Further, since the received numerical value is the total number of power supply devices driven upstream, the total power capacity It is possible to derive Psum and to know how many power supply devices 100 are connected upstream.

  Also, as shown in FIG. 6 and FIG. 7, if the transmission of information between the power supply devices 100 is made into a simple numerical value, for example, a numerical value that can be expressed by 3 bits (equivalent to 8 units), the transmission structure can be easily configured. Can do. In the present embodiment, as shown in FIG. 1, the transmission window 134 for the light emitting element 182 and the transmission window 136 for the light receiving element 180 are provided corresponding to the front and back of the power supply device 100, as shown in FIG. 4. When the power supply apparatus 100 is superposed, the upstream light emitting element 182 and the one-stage downstream light receiving element 180 face each other. In this way, information can be transmitted between the light emitting element 182 and the light receiving element 180. Here, an LED (Light Emitting Diode) or a lamp can be used as the light emitting element 182.

  The light receiving element 180 of the power supply apparatus 100 obtains information of a predetermined number of bits, for example, 3 bits, from the upstream light emitting element 182, grasps the upstream total power capacity from the value, and has its own single power capacity, for example, 1 Is added to derive the total power capacity up to itself. The value is displayed by the light emitting element 182 and transmitted to the downstream power supply apparatus 100. In addition, when only one bit is prepared for each of the light emitting element 182 and the light receiving element 180, information can be transmitted by the number of blinks and the light emission time (pulse width). Furthermore, it is also possible to transmit by superimposing an electric signal indicating the power capacity on the main power line from the output outlet 126 to the input plug 120.

  With such a configuration, it is possible to transmit power capacity while maintaining insulation and waterproofing by simply facing the light emitting element 182 and the light receiving element 180 without complicated electrical connection. Therefore, it is possible to connect a plurality of power supply devices 100 only by connecting the input plug 120 to the output outlet 126 of the upstream power supply device 100.

(Second Embodiment)
The current control unit 156 in the first embodiment described above controls both the reactive power deviation ΔQ and the active power deviation ΔP between the total current Isum and the output current Iind from the inverter 142. The cross current that forms part of the deviation ΔQ of the reactive power may occur when the output of the power supply device is very low compared to the rating, but the cross current becomes a negligible level when used almost at the rating. In the second embodiment, it is possible to balance the load current while reducing the processing load by permitting the cross current due to the voltage phase difference between the load current and the cross current and controlling only the load current.

  FIG. 8 is an electrical block diagram illustrating the overall electrical function of the power supply apparatus 200 according to the second embodiment. Here, the power supply device 200 includes an input plug 120, a connection switching unit 150, a charger 140, a secondary battery 128, an inverter 142, an output outlet 126, a current measuring unit 152, and a prorated current deriving unit 154. And a current control unit 256 and a power addition unit 158. The input plug 120, the connection switching unit 150, the charger 140, the secondary battery 128, the inverter 142, the output outlet 126, the current measuring unit 152, and the apportionment already described as the constituent elements in the first embodiment. Since the current deriving unit 154 and the power adding unit 158 have substantially the same function, a duplicate description is omitted, and here, the current control unit 256 having a different configuration will be mainly described.

  Similar to the current control unit 156 in the first embodiment, the current control unit 256 controls the output current Iind from the inverter 142 so as to become a current Iind ′ that is prorated by the apportioning current deriving unit 154. However, the current control unit 256 in the second embodiment allows a cross current due to a voltage phase difference.

  Therefore, the current control unit 256 sets the voltage of the inverter 142 so that the deviation ΔI between the current Iind ′ obtained by apportioning the current (total current) Isum passing through the output outlet 126 and the output current Iind from the inverter 142 becomes zero. Control. Specifically, voltage Vind of inverter 142 is adjusted through pulse width modulation by PI control unit 274 and PWM 176.

  FIG. 9 is an explanatory diagram showing a schematic control system of the current control unit 256 of the second embodiment. The current control unit 256 has an outer loop (current loop) indicated by a one-dot chain line in FIG. 9 as a target value and a current Iind ′ obtained by dividing the total current Isum as a target value and an output current Iind from the inverter 142 as a controlled variable. The voltage converted value Vtrg obtained by multiplying the difference between the apportioned current Iind ′ and the output current Iind from the inverter 142 by the proportional constant by the amplifier 278 is set as a target value, and the voltage Vind of the inverter 142 is set as a controlled variable. It consists of an inner loop (voltage loop) indicated by a chain line.

  Here, the output current Iind from the inverter 142 is closed-loop controlled using the voltage conversion value Vtrg. That is, current control based on the apportioned current Iind 'is performed. However, when itself is positioned at the most upstream, the apportioning current Iind 'and the output current Iind are equal, the outer loop is invalidated, and voltage control by the inner loop is the main control. That is, voltage control is performed in the most upstream power supply apparatus 200, and current control is performed in the downstream power supply apparatus 200.

  In the feedback control of the output current Iind and the voltage Vind of the inverter 142, a deviation between the apportioned current Iind ′ and the output current Iind corresponding to the cross current remains. However, as the load increases, the ratio of the cross current to the current decreases. It doesn't cause much problem. By such feedback control, it becomes possible to supply the stable output current Iind of the inverter 142, and the power supply apparatus 200 can take a share of the total current Isum.

  In the present embodiment, PI control by the PI control unit 274 is performed on the inner loop of the current control unit 256. P control (proportional control) functions as a proportional gain in the inner loop, and I control (integral control) absorbs a steady-state deviation over time that cannot be eliminated by P control. With this configuration, since it is not necessary to raise the proportional gain P transiently in order to eliminate the steady deviation, it is possible to supply stable power without causing problems such as vibration.

  Further, the current control unit 256 includes a feed forward by a deviation Vabm from the reference voltage Vref in its own system. Here, the reference voltage Vref is a fixed value based on the voltage table. Only the feedback control by the outer loop and the inner loop described above has a large influence on the inner loop due to the fluctuation of the voltage conversion value Vtrg, and may disturb the control of the inner loop. In the present embodiment, it is possible to appropriately absorb the fluctuation of the voltage conversion value Vtrg by feedforward, and to supply stable power without disturbing the voltage control of the original inverter.

  In the current control unit 256 of the second embodiment, the cross current due to the voltage phase difference is allowed among the load current and the cross current, and the control target is simplified to only the load current, thereby reducing the processing load and reducing the load current. It is possible to achieve a balance and speed up the control signal calculation to the inverter 142. Such speeding up also improves the control delay, thereby reducing the phase difference and avoiding the cross current. Thus, stable power can be supplied from the inverter 142.

  As mentioned above, although preferred embodiment of this invention was described referring an accompanying drawing, it cannot be overemphasized that this invention is not limited to the example which concerns. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the claims, and these are naturally within the technical scope of the present invention. Understood.

  INDUSTRIAL APPLICABILITY The present invention can be used in a power supply device that can store power in a secondary battery in advance and supply power to a connected load alone.

It is the perspective view which showed the external appearance of the power supply device in 1st Embodiment. It is the electric block diagram which showed the partial function in the case of operating the power supply device in 1st Embodiment independently. It is the electric block diagram which showed the whole electrical function of the power supply device in 1st Embodiment. It is the external appearance perspective view which showed the assembly structure at the time of connecting the four power supply devices in 1st Embodiment. It is explanatory drawing for demonstrating current distribution at the time of connecting the several power supply device from which the power capacity in 1st Embodiment differs. It is explanatory drawing for demonstrating the other current distribution at the time of connecting the several power supply device from which the power capacity in 1st Embodiment differs. It is explanatory drawing for demonstrating the other electric current distribution at the time of connecting the several power supply device in which electric power capacity in 1st Embodiment is substantially equal. It is the electric block diagram which showed the whole electrical function of the power supply device in 2nd Embodiment. It is explanatory drawing which showed the schematic control system of the current control part of 2nd Embodiment. It is the block diagram which showed the example which supplies the electric power of the several power supply device in a prior art to one load. It is the block diagram which showed the other example which supplies the electric power of the several power supply device in a prior art to one load.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100, 200 ... Power supply device 120 ... Input plug 126 ... Output outlet 128 ... Secondary battery 140 ... Charger 142 ... Inverter 150 ... Connection switching part 152 ... Current measuring part 154 ... Prorated current deriving part 156, 256 ... Current control part 158 ... Power adding unit 180 ... Light receiving element 182 ... Light emitting element

Claims (13)

A secondary battery,
An inverter that converts DC power from the secondary battery into AC power;
An output outlet functioning as an output terminal of the converted AC power;
An input plug connected to the output outlet and conducting AC power from the upstream to the output outlet while the power supply is connected to another power supply; and
A current measuring unit for measuring a current passing through the output outlet;
All power supply devices connected upstream, and a proportional current deriving unit for deriving a current that is obtained by dividing the measured current by a ratio of a total power capacity of the power supply device and a single power capacity of only the power supply device;
A current control unit that controls the output current from the inverter to be the apportioned current;
A power supply device comprising: A charger for converting AC power input from the input plug into DC power and charging the secondary battery;
A connection switching unit that exclusively switches the connection between the input plug and the charger or the output outlet; and
The power supply device according to claim 1, further comprising:   The total power capacity is derived by a power adding unit that adds the single power capacity of the power supply apparatus to the power capacity of all the upstream connected power supply apparatuses received from the connected one-stage upstream power supply apparatus. The power supply device according to claim 1, wherein:   The power supply device according to claim 3, wherein the power addition unit further transmits the derived total power capacity to a connected downstream power supply device.   5. The power supply device according to claim 4, wherein, when no current is output from the inverter, the power addition unit transmits the power capacity received from the power supply device connected upstream to the downstream power supply device as it is. .   6. The power supply device according to claim 3, wherein the power capacity of the power supply device is expressed by a multiple of a predetermined unit power capacity. When the single power capacity of all the connected power supplies is substantially equal,
7. The total power capacity is a value obtained by adding 1 to the total number of upstream-connected power supply apparatuses received from the upstream power supply apparatus, and the single power capacity is represented by 1. The power supply device described in 1.   The current control unit controls the voltage and phase of the inverter so that a deviation between reactive power and active power between a current obtained by apportioning the measured current and an output current from the inverter becomes zero. The power supply device according to any one of claims 1 to 7.   The current controller according to claim 1, wherein the voltage of the inverter is controlled so that a deviation between a current obtained by apportioning the measured current and an output current from the inverter becomes zero. The power supply device according to any one of the above. The current controller is
An outer loop having the apportioned current as a target value and an output current from the inverter as a controlled variable;
An inner loop having a voltage converted value of a difference between the apportioned current and an output current from the inverter as a target value and a voltage of the inverter as a control amount;
The power supply device according to claim 9, comprising:   The power supply apparatus according to claim 10, wherein PI control is performed on the inner loop.   The power supply apparatus according to claim 10 or 11, wherein the current control unit includes feedforward in a system.   The power supply device according to any one of claims 1 to 12, wherein transmission / reception of power capacity between the power supply devices is performed by a light emitting element and a light receiving element provided in each.

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