Power calculation device, power calculation method, and power calculation program

Abstract

Provided are a power calculation device, a power calculation method, and a power calculation program capable of accurately grasping the power consumption of a load. 【Solution means】The power calculation device is provided in a power supply system that converts first pre-conversion power into first post-conversion power by a first power conversion unit, divides the first post-conversion power, and outputs it to a plurality of first loads respectively, and includes an output power calculation unit, a pre-conversion power calculation unit, and a conversion power calculation unit. The output power calculation unit calculates a plurality of first output powers respectively output to the plurality of first loads. The pre-conversion power calculation unit calculates the first pre-conversion power based on the correlation between the first pre-conversion power and the first post-conversion power and the plurality of calculated first output powers. The conversion power calculation unit calculates a plurality of first conversion powers obtained by respectively converting the plurality of first output powers as powers corresponding to the first pre-conversion power based on the power ratio between the plurality of first output powers and the calculated first pre-conversion power.

Description

Technical Field

[0001] The present invention relates to a power calculation device, a power calculation method, and a power calculation program.

Background Art

[0002] In order to achieve sustainability, which has become a global important issue, in IT (Information Technology) technology, reducing power consumption that leads to greenhouse gas emissions is an important measure. For example, due to the multi-functional nature of devices on the device side, there is a need to accurately grasp the power consumption for each function (hereinafter also referred to as "load"). Here, the accurate power consumption is not the pure power consumption purely consumed by the load, but rather how much of the pure power consumption occupies the power consumption of the power supply source that supplies power to the device. In other words, it is the power indicating how much impact the pure power consumption has on the power consumption of the power supply source.

[0003] However, in the power supply path from the power supply source to the load, if there are power loss elements (such as AC / DC converters, DC / DC converters, pattern wiring) that cause power losses, due to the influence of the power losses, it is difficult to determine how much of the pure power consumption of the load occupies the power consumption of the power supply source, and thus it is difficult to accurately grasp the power consumption of the load.

[0004] In addition, related to the technology for obtaining power consumption, Patent Document 1 discloses a technology for estimating the amount of self-consumed power within the generated power of a power consumer equipped with a solar power generation facility.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] An object of the present invention is to provide a power calculation device, a power calculation method, and a power calculation program capable of accurately grasping the power consumption of a load.

Means for Solving the Problems

[0007] According to the present invention, a power calculation device having the following configuration is provided. [1] A power calculation device provided in a power supply system that converts first pre-conversion power into first post-conversion power by a first power conversion unit, divides the first post-conversion power, and outputs it to a plurality of first loads respectively. The power calculation device includes an output power calculation unit, a pre-conversion power calculation unit, and a conversion power calculation unit. The output power calculation unit calculates a plurality of first output powers output to the plurality of first loads respectively. The pre-conversion power calculation unit calculates the first pre-conversion power based on a first correlation relationship between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers. The conversion power calculation unit calculates a plurality of first conversion powers obtained by converting the plurality of first output powers respectively as powers corresponding to the first pre-conversion power based on a power ratio between the plurality of first output powers and the calculated first pre-conversion power.

[0008] According to the present invention, a plurality of first output powers output to a plurality of first loads respectively are calculated. Based on a first correlation relationship between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers, the first pre-conversion power is calculated. As powers corresponding to the first pre-conversion power, a plurality of first conversion powers obtained by converting the plurality of first output powers output to the plurality of first loads respectively are calculated. In other words, the power consumed by the plurality of first loads (the degree of influence of the power consumption of the plurality of first loads on the first pre-conversion power) on the upstream side of the first power conversion unit in the power supply path is calculated. Therefore, a user referring to the calculated first conversion power can accurately grasp the power consumption of the first load while taking into account the influence of power loss.

[0009] Hereinafter, various embodiments of the present invention will be exemplified. The embodiments shown below can be combined with each other. [2][1] The power calculation device according to [2][1], wherein the first load converts second pre-conversion power, which is the first output power obtained by dividing the first post-conversion power, into second post-conversion power by a second power conversion unit, divides the second post-conversion power, and outputs it to a plurality of second loads respectively. The output power calculation unit calculates a plurality of second output powers output to the plurality of second loads respectively. The pre-conversion power calculation unit calculates the second pre-conversion power based on a second correlation relationship between the second pre-conversion power and the second post-conversion power, and the calculated plurality of second output powers. The converted power calculation unit calculates a plurality of second converted powers obtained by converting the plurality of second output powers respectively as powers corresponding to the first converted power based on a power ratio between the plurality of second output powers and the first converted power calculated corresponding to the first load. [3][1] The power calculation device according to [3][1], wherein the first correlation relationship is a correlation relationship considering power loss characteristics in the first power conversion unit. [4][1] The power calculation device according to any one of [4][1] to [3], further comprising a display control unit, wherein the display control unit causes a display device to display the calculated plurality of first converted powers in an identifiable manner. [5][1] The power calculation device according to any one of [5][1] to [4], further comprising a correlation relationship setting unit, wherein the correlation relationship setting unit sets the first correlation relationship according to a supply state supplied to the first power conversion unit. [6] A power calculation method executed in a power supply system that converts first pre-conversion power into first post-conversion power by a first power conversion unit, divides the first post-conversion power, and outputs it to a plurality of first loads respectively. The method includes an output power calculation step, a first power calculation step, and a conversion power calculation step. In the output power calculation step, a plurality of first output powers output to the plurality of first loads respectively are calculated. In the pre-conversion power calculation step, based on a first correlation relationship between the first pre-conversion power and the first post-conversion power, and the calculated plurality of first output powers, the first pre-conversion power is calculated. In the conversion power calculation step, based on the power ratio between the plurality of first output powers and the calculated first pre-conversion power, a plurality of first conversion powers obtained by converting the plurality of first output powers respectively as powers corresponding to the first pre-conversion power are calculated. [7] A power calculation program for causing a processor to execute the power calculation method according to [6].

Advantages of the Invention

[0010] According to the present invention, as powers corresponding to the first pre-conversion power, a plurality of first conversion powers obtained by converting a plurality of first output powers output to a plurality of first loads respectively are calculated. In other words, the power consumed by a plurality of first loads on the upstream side of the first power conversion unit in the power supply path (the degree of influence of the power consumption of the plurality of first loads on the first pre-conversion power) is calculated. Therefore, a user referring to the first conversion power can accurately grasp the power consumption of the load in consideration of the influence of power loss.

Brief Description of the Drawings

[0011]

Figure 1

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Figure 10

MODE FOR CARRYING OUT THE INVENTION

[0012] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Each feature shown in the embodiments described below can be combined with each other. In addition, an invention can be established independently for each feature.

[0013] FIG. 1 is a block diagram showing the configuration of a power supply system 1 according to an embodiment of the present invention. As shown in FIG. 1, the power supply system 1 includes a first power supply source 2, a first power conversion unit 3, a first resistance unit 4, a display device 5, a second resistance unit 6, an external device 7, a measurement unit 8, a switch 9, and a power calculation device 10. Note that the display device 5 and the external device 7 function as the "plurality of first loads" of the present invention. In addition, the first power supply source 2, the first power conversion unit 3, the first resistance unit 4, the display device 5, the second resistance unit 6, the external device 7, the measurement unit 8, the switch 9, and the power calculation device 10 included in the power supply system 1 may be configured as one device (for example, a monitor device).

[0014] The power supply system 1 converts the first pre-conversion power (primary-side power, e.g., 60 W) supplied from the first power supply source 2 into the first post-conversion power (secondary-side power, e.g., 50 W) by the first power conversion unit 3, and divides the first post-conversion power to output it to a plurality of first loads (display device 5, external device 7) respectively.

[0015] The first power supply source 2 is, for example, a power supply unit, which is connected to a household AC outlet or the like via an electrical cord or the like and outputs an AC voltage (e.g., 100 V). Note that the first power supply source 2 is not limited to a power supply unit, and may be, for example, a 100V or 200V commercial power system or USB PD (USB POWER DELIVERY) power supply. However, the first power supply source 2 does not necessarily have to be an element that supplies power by itself. For example, like the second power supply source 2A in FIG. 10, it may correspond to the power (second pre-conversion power, which is a part of the first post-conversion power) output from the first power conversion unit 3 and supplied to the second power conversion unit 3A.

[0016] The first power conversion unit 3 is, for example, an AC / DC converter, which converts the AC power supplied from the first power supply source 2 to generate DC power, and supplies the generated DC power to the display device 5 and the external device 7. Note that the first power conversion unit 3 may be any device that converts the input power into the output power in some manner. When a DC voltage is output from the first power supply source 2, it may be a DC / DC converter that transforms the DC voltage into a voltage suitable for the inputs of the display device 5 and the external device 7. Also, the first power conversion unit 3 may be configured to include both an AC / DC converter and a DC / DC converter, or may be configured to include, in addition to the AC / DC converter or the DC / DC converter, for example, a resistance circuit that generates power loss, or may be configured to include only the resistance circuit without including the AC / DC converter or the DC / DC converter.

[0017] The first resistor 4 is, for example, a current detection resistor (shunt resistor) provided between the first power conversion unit 3 and the display device 5 in the power supply path of the power supply system 1. One end of the first resistor 4 is connected to the branch point 1a of the first resistor 4 and the second resistor 6 in the power supply path, and the other end of the first resistor 4 is connected to the display device 5.

[0018] The display device 5 is, for example, a liquid crystal display device having a display panel including a plurality of pixels arranged on a substrate, and displays an image based on image data.

[0019] The second resistor 6 is, for example, a current detection resistor (shunt resistor) provided between the first power conversion unit 3 and the external device 7 in the power supply path of the power supply system 1. One end of the second resistor 6 is connected to the branch point 1a of the first resistor 4 and the second resistor 6 in the power supply path, and the other end of the second resistor 6 is connected to the external device 7.

[0020] The external device 7 is a peripheral device capable of USB connection, such as a notebook PC, a tablet, a household electrical appliance, a smartphone, a storage (memory device), etc.

[0021] The measurement unit 8 includes, for example, a current sense amplifier. One end is connected to the branch point 1a of the first resistor 4 and the second resistor 6 in the power supply path, and the other end is connected to the switch 9. The current sense amplifier is a differential amplifier that outputs an analog voltage proportional to the current flowing through the load connected to the input.

[0022] The switch 9 receives the control of the measurement unit 8 and switches the connection destination of the other end of the measurement unit 8 between the other end of the first resistor 4 and the other end of the second resistor 6.

[0023] The measurement unit 8 measures the current flowing through the first resistor 4 or the current flowing through the second resistor 6 in a time-division manner. For example, in a state where the measurement unit 8 controls the switch 9 and switches the connection destination of the other end of the measurement unit 8 to the other end of the first resistor 4 (the state shown in FIG. 1), the voltage across the first resistor 4 (specifically, between one end and the other end of the measurement unit 8) is measured, thereby measuring the current flowing through the first resistor 4 and thus the current flowing through the display device 5. Then, the measurement unit 8 outputs first current information indicating the current value of the current flowing through the display device 5 to the power calculation device 10. Note that the measurement unit 8 may measure the current flowing through the display device 5 using, for example, a magnetic field detection type current sensor IC without using the first resistor 4.

[0024] Also, in a state where the measurement unit 8 controls the switch 9 and switches the connection destination of the other end of the measurement unit 8 to the other end of the second resistor 6, the voltage across the second resistor 6 (specifically, between one end and the other end of the measurement unit 8) is measured, thereby measuring the current flowing through the second resistor 6 and thus the current flowing through the external device 7. Then, the measurement unit 8 outputs second current information indicating the current value of the current flowing through the external device 7 to the power calculation device 10. Note that the measurement unit 8 may measure the current flowing through the external device 7 using, for example, a magnetic field detection type current sensor IC without using the second resistor 6.

[0025] Note that the power supply system 1 may include two measurement units that respectively measure the current flowing through the first resistor 4 and the current flowing through the second resistor 6 instead of the measurement unit 8 and the switch 9. However, from the perspective of reducing the circuit cost of the measurement circuit by using one measurement circuit to measure the current flowing through the first resistor 4 and the current flowing through the second resistor 6 respectively compared to the case of including two measurement units, it is preferable that the measurement unit 8 measures the current flowing through the first resistor 4 or the current flowing through the second resistor 6 in a time-division manner.

[0026] The power calculation device 10 is, for example, a microcomputer, and is configured such that the user can accurately grasp the power consumption of a plurality of first loads (in this embodiment, the display device 5 and the external device 7) provided in the power supply path of the power supply system 1.

[0027] FIG. 2 is a block diagram showing the hardware configuration of the power calculation device 10 in the present embodiment. As shown in FIG. 2, the power calculation device 10 includes a control unit 11, a storage unit 12, a communication unit 13, and an operation input unit 14. In the present embodiment, an example in which the power calculation device 10 and the display device 5 are configured separately will be described, but the power calculation device 10 and the display device 5 may be integrally configured.

[0028] The control unit 11 is, for example, a CPU (Central Processing Unit), a microprocessor, a DSP (Digital Signal Processor), etc., and controls the overall operation of the power calculation device 10. Note that the control unit 11 may be configured by various circuits such as an ASIC (Application Specific Integrated Circuit) and an FPGA (Programmable Logic Circuit Device), or may be configured by a combination of a processor and a circuit.

[0029] A part of the storage unit 12 is configured by, for example, a RAM (Random Access Memory) or a DRAM (Dynamic Random Access Memory), and is used as a work area when executing processing based on various programs by the control unit 11.

[0030] Also, a part of the storage unit 12 is, for example, a non-volatile memory such as a ROM (Read Only Memory) or an HDD (Hard Disk Drive), and stores various data and programs used for the processing of the control unit 11. The storage unit 12 can hold a database including one or more tables for recording various information and processing results.

[0031] The programs stored in the storage unit 12 are, for example, an OS (Operating System) for realizing the basic functions of the power calculation device 10, drivers for controlling various hardware, programs for realizing various functions, etc., and include a program that functions as the "power calculation program" of the present invention.

[0032] The communication unit 13 is, for example, a NIC (Network Interface Controller) and has a function of connecting to a communication line (not shown). Note that the communication unit 13 may have a function of connecting to a wireless LAN (Local Area Network), a function of connecting to a wireless WAN (Wide Area Network), a function enabling short-distance wireless communication such as Bluetooth (registered trademark), wired communication such as USB, and infrared communication, instead of or together with the NIC. The power calculation device 10 is connected to the display device 5 etc. via a communication line and can transmit and receive various data to and from the display device 5 etc.

[0033] The operation input unit 14 is composed of, for example, a keyboard, a mouse, a touch panel, a switch, etc., and accepts input of various operations by a user who uses the power calculation device 10.

[0034] The control unit 11, the storage unit 12, the communication unit 13, and the operation input unit 14 are electrically connected to each other via a system bus 15. Therefore, the control unit 11 can access the storage unit 12, grasp the operation state of the operation input unit 14 by the user, and access various communication networks and the display device 5 etc. via the communication unit 13.

[0035] FIG. 3 is a block diagram showing a functional configuration example of the control unit 11 included in the power calculation device 10 in the present embodiment. As shown in FIG. 3, the control unit 11 includes, as functional configurations, an output power calculation unit 11a, a pre-conversion power calculation unit 11b, a converted power calculation unit 11c, a display control unit 11d, and a correlation relationship setting unit 11e. Note that generally the control unit 11 of the power calculation device 10 has various other functions, but here, only the functions characteristic in obtaining the power consumption of a plurality of first loads (display device 5, external device 7) provided in the power supply path of the power supply system 1 will be described, and illustration and description of other known functions etc. will be omitted.

[0036] The output power calculation unit 11a calculates the first output power output to the display device 5 and the external device 7 provided in the power supply path of the power supply system 1, respectively. Specifically, the output power calculation unit 11a multiplies the current value indicated by the first current information output from the measurement unit 8 (the current value of the current flowing through the display device 5) by the voltage supplied to the display device 5 to calculate the power consumed by the display device 5 (for example, 35 W) as the first output power output to the display device 5. Further, the output power calculation unit 11a multiplies the current value indicated by the second current information output from the measurement unit 8 (the current value of the current flowing through the external device 7) by the voltage supplied to the external device 7 to calculate the power consumed by the external device 7 (for example, 45 W) as the first output power output to the external device 7.

[0037] The pre-conversion power calculation unit 11b calculates the first pre-conversion power based on the first correlation relationship between the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 and the first post-conversion power supplied after conversion by the first power conversion unit 3, and the first output power to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (corresponding to the first post-conversion power, the power obtained by summing the first output powers to the display device 5 and the external device 7).

[0038] The first correlation relationship is, for example, a correlation relationship considering the power loss characteristics in the first power conversion unit 3 (including non-linear or linear conversion efficiency characteristics such as an AC / DC converter or a DC / DC converter, and power loss characteristics due to a predetermined load such as a resistance circuit). The first correlation relationship can be obtained by experiments or the like that measure in advance how the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 changes in response to the change in the first post-conversion power after conversion by the first power conversion unit 3.

[0039] FIG. 4 is a diagram showing an example of a first correlation relationship between the power before the first conversion and the power after the first conversion. As shown in FIG. 4, the first correlation relationship between the power before the first conversion and the power after the first conversion is represented by a non-linear quadratic equation L1. For example, when the power after the first conversion (the sum value of the first output power to the display device 5 and the external device 7) is 80 W, 90 W can be obtained as the power before the first conversion through the non-linear quadratic equation L1. In this case, the ratio of the power before the first conversion to the power after the first conversion is 1.125:1. Also, when the power after the first conversion is 46 W, 56.6 W can be obtained as the power before the first conversion through the non-linear quadratic equation L1. In this case, the ratio of the power before the first conversion to the power after the first conversion is approximately 1.23:1. That is, when the power after the first conversion is 80 W, the ratio of the power before the first conversion to the power after the first conversion is smaller (not constant) compared to the case when the power after the first conversion is 46 W. The correlation relationship information indicating the first correlation relationship between the power before the first conversion and the power after the first conversion is stored in the storage unit 12 in the form of a table or an approximate equation.

[0040] As described above, the pre-conversion calculation unit 11b refers to the correlation relationship information stored in the storage unit 12, and calculates the first power before conversion (for example, 90 W) based on the first power after conversion (for example, 80 W) obtained by summing the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a.

[0041] The conversion power calculation unit 11c calculates two first converted powers obtained by converting two first output powers (for example, display device 5: 35 W, external device 7: 45 W) respectively as the power corresponding to the first power before conversion (for example, 90 W) based on the power ratio between the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (for example, 35 W:45 W = 7:9) and the first power before conversion (for example, 90 W) calculated by the pre-conversion power calculation unit 11b.

[0042] When the power before the first conversion is represented by P1 (e.g., 90 W), the first output power to the display device 5 is represented by OP1 (e.g., 35 W), and the power after the first conversion is represented by P2 (e.g., 80 W), the first converted power P11 (e.g., 39.375 W) of the display device 5 is calculated by the following formula (1).

[0043]

Equation

[0044] Also, when the power before the first conversion is represented by P1 (e.g., 90 W), the first output power to the external device 7 is represented by OP2 (e.g., 45 W), and the power after the first conversion is represented by P2 (e.g., 80 W), the first converted power P12 (e.g., 50.625 W) of the external device 7 is calculated by the following formula (2).

[0045]

Equation

[0046] The display control unit 11d outputs, to the display device 5, image data indicating the converted power of at least one of the display device 5 and the external device 7 calculated by the converted power calculation unit 11c, and controls the display device 5 to display (e.g., on-screen display) the first converted power of at least one of the display device 5 and the external device 7 in an identifiable manner. Note that the display control unit 11d may cause the display device 5 to display not only the first converted power of the display device 5 and the external device 7 but also at least one of the first output power output to the display device 5, the first output power output to the external device 7, the power before the first conversion, and the power after the first conversion, which are the powers obtained in the process of calculating the first converted power of the display device 5 and the external device 7.

[0047] FIG. 5 is an example of a display screen 20 displayed on the display device 5. As shown in FIG. 5, in the upper left part of the display screen 20, a converted power image 30 is displayed using the icons of the display device 5 and the external device 7 to indicate that the first converted power of the display device 5 is 6W and the first converted power of the external device 7 is 54W. A user referring to the converted power image 30 can accurately grasp the power consumption of the first load (display device 5 and external device 7) in consideration of the influence of the power loss by the first power conversion unit 3.

[0048] Note that in the display screen 20, the converted power image 30 may be displayed in the upper right part, the lower left part, or the lower right part instead of the upper left part, or may be displayed in a part selected by the user from among a plurality of parts. Further, from the viewpoint of suppressing a decrease in the visibility of other display images due to the display of the converted power image 30 on the display screen 20, the transmittance of the converted power image 30 displayed on the display screen 20 may be arbitrarily changeable by the user.

[0049] The correlation relationship setting unit 11e sets the first correlation relationship referred to by the pre-conversion power calculation unit 11b according to the supply voltage (corresponding to the "supply state" of the present invention) supplied from the first power supply source 2 to the first power conversion unit 3. For example, the correlation relationship setting unit 11e sets, as the first correlation relationship referred to by the pre-conversion power calculation unit 11b, a correlation relationship designed such that the calculation accuracy of the first pre-conversion power according to the first post-conversion power is optimal when the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 is 100V. Further, the correlation relationship setting unit 11e sets, as the first correlation relationship referred to by the pre-conversion power calculation unit 11b, a correlation relationship designed such that the calculation accuracy of the first pre-conversion power according to the first post-conversion power is optimal when the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 is 200V. Thereby, even if the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 is changed, an optimal first correlation relationship is set in consideration of the change, so that the calculation accuracy of the first pre-conversion power can be optimally maintained.

[0050] Note that the correlation relationship setting unit 11e may automatically set the first correlation relationship referred to by the pre-conversion power calculation unit 11b according to the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3. Further, when a switching instruction by the user occurs, the correlation relationship setting unit 11e may switch and set the first correlation relationship according to the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3. Further, the correlation relationship setting unit 11e may set the first correlation relationship referred to by the pre-conversion power calculation unit 11b according to how the power is supplied to the first power supply source 2, for example, by any one of USB PD power supply, AC input, DC input, and battery power supply (corresponding to the "supply state" of the present invention).

[0051] FIG. 6 is a flowchart showing an example of the power calculation process (corresponding to the "power calculation method" of the present invention) performed by the power calculation device 10 in the present embodiment. The power calculation process performed by the power calculation device 10 is executed, for example, every time a predetermined time elapses.

[0052] First, the output power calculation unit 11a calculates the first output power output to the display device 5 and the external device 7 provided in the power supply path of the power supply system 1, respectively (step S100).

[0053] Next, the pre-conversion power calculation unit 11b calculates the first converted power after conversion by the first power conversion unit 3 by adding up the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a in step S100 (step S110).

[0054] Next, the pre-conversion power calculation unit 11b calculates the first pre-conversion power based on the first correlation relationship between the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 and the first converted power after conversion by the first power conversion unit 3, and the first converted power calculated in step S110 (the power obtained by adding up the first output powers to the display device 5 and the external device 7) (step S120).

[0055] Next, the conversion power calculation unit 11c calculates two first conversion powers by converting the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a into powers corresponding to the first power before conversion based on the power ratio between the first output powers to the display device 5 and the external device 7 and the first power before conversion calculated in step S120 (step S130).

[0056] Finally, the display control unit 11d outputs image data indicating the first conversion powers of the display device 5 and the external device 7 calculated in step S130 to the display device 5, and controls the display device 5 to display the first conversion powers of the display device 5 and the external device 7 in an identifiable manner (step S140). When the process of step S140 is completed, the power calculation device 10 ends the power calculation process shown in FIG. 6.

[0057] As described in detail above, in the present embodiment, the power calculation device 10 is provided in the power supply system 1 that converts the first power before conversion into the first power after conversion by the first power conversion unit 3, divides the first power after conversion, and outputs it to a plurality of first loads (display device 5 and external device 7), respectively. The power calculation device 10 includes an output power calculation unit 11a, a power before conversion calculation unit 11b, and a conversion power calculation unit 11c. The output power calculation unit 11a calculates a plurality of first output powers output to the plurality of first loads, respectively. The power before conversion calculation unit 11b calculates the first power before conversion based on the first correlation relationship between the first power before conversion and the first power after conversion and the plurality of first output powers (total power) calculated by the output power calculation unit 11a. The conversion power calculation unit 11c calculates a plurality of first conversion powers by converting the plurality of first output powers into powers corresponding to the first power before conversion based on the power ratio between the plurality of first output powers and the first power before conversion calculated by the power before conversion calculation unit 11b.

[0058] According to the present embodiment configured as described above, as the power corresponding to the pre-first-conversion power, a plurality of first converted powers obtained by converting a plurality of first output powers respectively output to a plurality of first loads (display device 5 and external device 7), in other words, the power consumed by the plurality of first loads on the upstream side of the first power conversion unit 3 in the power supply path of the power supply system 1 is calculated. Therefore, the user referring to the first converted power can accurately grasp the power consumption of the first loads (display device 5 and external device 7) taking into account the influence of the power loss by the first power conversion unit 3.

[0059] In the above embodiment, an example where the display device 5 and the external device 7 function as the "plurality of first loads" of the present invention has been described. However, the present invention is not limited to this. For example, instead of two devices (apparatuses), three or more devices (apparatuses) may function as the "plurality of first loads" of the present invention, or one device (apparatus) and a group of devices including two or more devices (apparatuses) may function as the "plurality of first loads" of the present invention.

[0060] Also, in the above embodiment, the output power calculation unit 11a may calculate the first output power output to the external device 7 by subtracting the first output power output to the display device 5 from the first post-conversion power after the conversion by the first power conversion unit 3. Also, the output power calculation unit 11a may calculate the first output power output to the display device 5 by subtracting the first output power output to the external device 7 from the first post-conversion power after the conversion by the first power conversion unit 3. Referring to FIG. 7, a power supply system 1 configured to calculate the first post-conversion power supplied after the conversion by the first power conversion unit 3 and the first output power output to the display device 5 will be described.

[0061] FIG. 7 is a block diagram showing a modified example of the configuration of the power supply system 1. As shown in FIG. 7, the first resistor unit 4 is a current detection resistor (shunt resistor) provided between the first power conversion unit 3 and the branch point 1a in the power supply path of the power supply system 1. The branch point 1a is a point where the power supply path 1b for dividing the first converted power converted by the first power conversion unit 3 and outputting it to the display device 5 and the power supply path 1c for dividing the first converted power converted by the power conversion unit 3 and outputting it to the external device 7 branch. One end of the first resistor unit 4 is connected to the first power conversion unit 3, and the other end of the first resistor unit 4 is connected to the branch point 1a.

[0062] The second resistor unit 6 is a current detection resistor (shunt resistor) provided between the branch point 1a and the display device 5 in the power supply path of the power supply system 1. One end of the second resistor unit 6 is connected to the branch point 1a, and the other end of the second resistor unit 6 is connected to the display device 5.

[0063] One end of the measurement unit 8 is connected to one end of the first resistor unit 4, and the other end of the measurement unit 8 is connected to the switch 9. The switch 9 switches the connection destination of the other end of the measurement unit 8 between the other end of the first resistor unit 4 and the other end of the second resistor unit 6 under the control of the measurement unit 8.

[0064] The measurement unit 8 measures the current flowing through the first resistor unit 4 or the current flowing through the second resistor unit 6 in a time-division manner. For example, the measurement unit 8 measures the current flowing through the first resistor unit 4 by measuring the voltage across the first resistor unit 4 (specifically, between one end and the other end of the measurement unit 8) in a state where the switch 9 is controlled and the connection destination of the other end of the measurement unit 8 is switched to the other end of the first resistor unit 4 (the state shown in FIG. 7). Then, the measurement unit 8 outputs first current information indicating the current value of the current flowing through the first resistor unit 4 to the power calculation device 10.

[0065] Further, in a state where the measurement unit 8 controls the switch 9 and switches the connection destination of the other end of the measurement unit 8 to the other end of the second resistor unit 6, the voltage between the second resistor units 6 (specifically, between one end and the other end of the measurement unit 8) is measured, whereby the current flowing through the second resistor unit 6 and thus the current flowing through the display device 5 are measured. Then, the measurement unit 8 outputs second current information indicating the current value of the current flowing through the display device 5 to the power calculation device 10.

[0066] The output power calculation unit 11a (control unit 11) of the power calculation device 10 multiplies the current value indicated by the first current information output from the measurement unit 8 (the current value of the current flowing through the first resistor unit 4) by the output voltage of the first power conversion unit 3, thereby calculating the first converted power (for example, 40 W) supplied after conversion by the first power conversion unit 3. Further, the output power calculation unit 11a multiplies the current value indicated by the second current information output from the measurement unit 8 (the current value of the current flowing through the display device 5) by the voltage supplied to the display device 5, thereby calculating the power consumed by the display device 5 (for example, 5 W) as the first output power output to the display device 5. Then, after calculating the first converted power (for example, 40 W) supplied after conversion by the first power conversion unit 3 and the first output power (for example, 5 W) output to the display device 5, the output power calculation unit 11a subtracts the first output power from the first converted power to calculate the first output power (for example, 35 W) output to the external device 7.

[0067] Further, in the above embodiment, the first correlation relationship between the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 and the first post-conversion power supplied after conversion by the first power conversion unit 3 is not limited to the example shown in FIG. 4. FIG. 8 is a diagram showing a modified example of the first correlation relationship between the first pre-conversion power and the first post-conversion power. As shown in FIG. 8, the first correlation relationship between the first pre-conversion power and the first post-conversion power is represented by a linear first-order equation L2. For example, when the first post-conversion power is 50 W, 60 W can be obtained as the first pre-conversion power through the linear first-order equation L2. For example, it is assumed that the output power calculation unit 11a calculates the power consumed by the display device 5 (for example, 5 W) as the first output power output to the display device 5 and the power consumed by the external device 7 (for example, 45 W) as the first output power output to the external device 7.

[0068] In this case, the pre-conversion power calculation unit 11b calculates the first correlation relationship between the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 and the first post-conversion power supplied after conversion by the first power conversion unit 3 (for example, the first correlation relationship shown in FIG. 8), and the first output power to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (corresponding to the first post-conversion power, the power obtained by summing the first output powers to the display device 5 and the external device 7, for example, 50 W), and calculates the first pre-conversion power (for example, 60 W).

[0069] The conversion power calculation unit 11c calculates two first conversion powers (for example, display device 5: 6 W, external device 7: 54 W) obtained by converting two first output powers (for example, display device 5: 5 W, external device 7: 45 W) as the powers corresponding to the first pre-conversion power (for example, 60 W) based on the power ratio between the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (for example, 5 W: 45 W = 1: 9) and the first pre-conversion power (for example, 60 W) calculated by the pre-conversion power calculation unit 11b.

[0070] FIG. 9 is a diagram showing a modification of the first correlation relationship between the power before the first conversion and the power after the first conversion. As shown in FIG. 9, the first correlation relationship between the power before the first conversion and the power after the first conversion is represented by a linear first-order equation L3. For example, when the power after the first conversion is 80 W, 100 W can be obtained as the power before the first conversion through the linear first-order equation L3).

[0071] In the above embodiment, the power calculation process performed by the power calculation device 10 has been described by taking as an example the case where it is executed every time a predetermined time elapses, but the present invention is not limited to this. For example, the power calculation process performed by the power calculation device 10 may be executed every time the operating state of the first load (for example, the display device 5) changes. For example, when the operating state of the display device 5 is the normal operating state, the output power calculation unit 11a calculates the power consumed by the display device 5 (for example, 35 W) as the first output power output to the display device 5, and calculates the power consumed by the external device 7 (for example, 45 W) as the first output power output to the external device 7.

[0072] In this case, the power calculation unit 11b before conversion calculates the first correlation relationship between the first power before conversion supplied from the first power supply source 2 to the first power conversion unit 3 and the first power after conversion supplied after conversion by the first power conversion unit 3 (for example, the first correlation relationship shown in FIG. 4), and the first output power to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (corresponding to the first power after conversion, the power obtained by summing the first output powers to the display device 5 and the external device 7, for example, 80 W), and calculates the first power before conversion (for example, 90 W).

[0073] The converted power calculation unit 11c calculates two first converted powers (for example, display device 5: 39.375 W, external device 7: 50.625 W) obtained by converting the two first output powers (for example, display device 5: 35 W, external device 7: 45 W) as the powers corresponding to the first power before conversion (for example, 90 W) based on the power ratio between the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (for example, 35 W: 45 W = 7: 9) and the first power before conversion (for example, 90 W) calculated by the power calculation unit 11b before conversion.

[0074] Also, when the operating state of the display device 5 is the standby state, assume that the output power calculation unit 11a calculates the power consumed by the display device 5 (e.g., 1W) as the first output power output to the display device 5, and calculates the power consumed by the external device 7 (e.g., 45W) as the first output power output to the external device 7.

[0075] In this case, based on the first correlation relationship (e.g., the correlation relationship shown in FIG. 4) between the first pre-conversion power supplied from the first power supply source 2 to the first power conversion unit 3 and the first post-conversion power supplied after conversion by the first power conversion unit 3, and the first output power (corresponding to the first post-conversion power, the power obtained by summing the first output powers to the display device 5 and the external device 7, e.g., 46W) to the display device 5 and the external device 7 calculated by the output power calculation unit 11a, the first pre-conversion power (e.g., 56.6W) is calculated.

[0076] The conversion power calculation unit 11c calculates two first conversion powers (e.g., for the display device 5: approximately 1.23W, for the external device 7: approximately 55.37W) by converting the two first output powers (e.g., for the display device 5: 1W, for the external device 7: 45W) respectively, as the powers corresponding to the first pre-conversion power (e.g., 56.6W), based on the power ratio between the first output powers to the display device 5 and the external device 7 calculated by the output power calculation unit 11a (e.g., 1W:45W = 1:45) and the first pre-conversion power (e.g., 56.6W) calculated by the pre-conversion power calculation unit 11b.

[0077] As described above, regardless of the operating state (normal operating state, standby state) of the display device 5, the first output power (e.g., 45 W) output to the external device 7 is constant. However, when the first output power output to the display device 5 and thus the first converted power changes from, for example, 80 W to 46 W in accordance with the change in the operating state of the display device 5, the first input power also changes from, for example, 90 W to 56.6 W in accordance with the first correlation. Therefore, even though the first output power output to the external device 7 is constant (e.g., 45 W), the first converted power obtained by converting the first output power to the external device 7 as the power corresponding to the first input power (normal operating state: 50.625 W, standby state: 55.37 W), that is, the degree of influence of the power consumption of the external device 7 on the first input power changes. Further, although the first input power is smaller in the standby state (e.g., 56.6 W) than in the normal operating state (e.g., 90 W), the first converted power obtained by converting the first output power to the external device 7 is larger in the standby state (e.g., 55.37 W) than in the normal operating state (e.g., 50.625 W). Thus, it is possible to accurately grasp the change in the power consumption of the external device 7 taking into account the influence of the power loss by the first power conversion unit 3.

[0078] Also, in the above embodiment, the power supply system 1 may include a load configured to perform power conversion internally. FIG. 10 is a block diagram showing a modified example of the configuration of the power supply system 1. As shown in FIG. 10, the power supply system 1 includes a first power supply source 2 and a first power conversion unit 3, and includes a display device 5 and a load 40 as two loads (corresponding to the "first load" of the present invention). The load 40 includes a second power supply source 2A and a second power conversion unit 3A, and includes a first external device 7A and a second external device 7B as two loads (corresponding to the "second load" of the present invention).

[0079] The first power conversion unit 3 is, for example, an AC / DC converter, which converts the AC power (the first pre-conversion power) supplied from the first power supply source 2 into DC power (the first post-conversion power), generates the generated DC power, divides it, and supplies it to the display device 5 and the load 40. The second power supply source 2A included in the load 40 supplies the DC power (the second pre-conversion power) supplied from the first power conversion unit 3 to the second power conversion unit 3A. The second power conversion unit 3A is, for example, a DC / DC converter, which converts the DC power (the second pre-conversion power) supplied from the second power supply source 2A into the second post-conversion power, divides the second post-conversion power, and outputs it to the first external device 7A and the second external device 7B as DC power (the second output power) suitable for the first external device 7A and the second external device 7B.

[0080] The control unit 11 of the power calculation device 10 calculates the power consumed by the display device 5 as the first output power supplied from the first power conversion unit 3A to the display device 5 and output therefrom in the same manner as the power calculation method described in the above embodiment. Further, the control unit 11 calculates the second output power supplied from the first power conversion unit 3A to the second power supply source 2A and output to the first external device 7A and the second external device 7B respectively via the conversion by the second power conversion unit 3A.

[0081] Based on the second correlation relationship between the second pre-conversion power supplied from the second power supply source 2A to the second power conversion unit 3A and the second post-conversion power supplied after the conversion by the second power conversion unit 3A in the load 40, and the total power (corresponding to the second post-conversion power) of the second output power to the calculated first external device 7A and second external device 7B, the control unit 11 calculates the second pre-conversion power supplied from the second power supply source 2A to the second power conversion unit 3A.

[0082] Based on the first correlation relationship between the first pre-conversion power supplied from the first power supply source 2 and the first post-conversion power supplied after the conversion by the first power conversion unit 3, the first output power to the display device 5, and the total power (corresponding to the first post-conversion power) of the first output power to the load 40 (corresponding to the calculated second pre-conversion power), the control unit 11 calculates the first pre-conversion power supplied from the first power supply source 2.

[0083] Based on the power ratio between the first output power to the display device 5 and the load 40 and the calculated first pre-conversion power, the control unit 11 calculates two first converted powers obtained by converting the first output power to the display device 5 and the load 40 respectively into the power corresponding to the first pre-conversion power. Then, based on the power ratio between the second output powers to the first external device 7A and the second external device 7B and the first converted power calculated corresponding to the load 40, the control unit 11 calculates two second converted powers obtained by converting the second output powers to the first external device 7A and the second external device 7B respectively into the power corresponding to the first converted power. In this way, by using the first converted power calculated corresponding to the load 40 to obtain the second converted powers of the first external device 7A and the second external device 7B, the power consumed by the two loads (the first external device 7A and the second external device 7B), that is, the influence of the power consumption of the first external device 7A and the second external device 7B on the first pre-conversion power, is calculated upstream of the first power conversion unit 3 located upstream of the second power conversion unit 3A in the power supply path of the power supply system 1. Note that the control unit 11 may display the image data indicating at least one of the calculated first converted power and the second converted power in an identifiable manner. Further, the control unit 11 may set the first correlation relationship and the second correlation relationship according to the supply voltage supplied to the first power conversion unit 3 and the supply voltage supplied to the second power conversion unit 3A.

[0084] As described above, as the power corresponding to the first pre-conversion power, three converted powers (the first converted power, the second converted power) obtained by converting the three output powers (the first output power, the second output power) respectively output to the three loads (the display device 5, the first external device 7A, and the second external device 7B) are calculated. In other words, since the power consumed by the three loads (the influence of the power consumption of the three loads on the first pre-conversion power) is calculated upstream of the first power conversion unit 3 in the power supply path of the power supply system 1, the user referring to the converted power can accurately grasp the power consumption of the loads (the display device 5, the first external device 7A, and the second external device 7B) taking into account the influence of the power loss by the first power conversion unit 3 and the second power conversion unit 3A.

[0085] As described above, various embodiments of the present invention have been explained. However, these are presented as examples and are not intended to limit the scope of the invention. The novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. Such embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0086] 1: Power supply system, 1a: Branch point, 1b, 1c: Power supply paths, 2: First power supply source, 2A: Second power supply source, 3: First power conversion unit, 3A: Second power conversion unit, 4: First resistance unit, 5: Display device, 6: Second resistance unit, 7: External device, 7A: First external device, 7B: Second external device, 8: Measurement unit, 9: Switch, 10: Power calculation device, 11: Control unit, 11a: Output power calculation unit, 11b: Pre-conversion power calculation unit, 11c: Conversion power calculation unit, 11d: Display control unit, 11e: Correlation relationship setting unit, 12: Storage unit, 13: Communication unit, 14: Operation input unit, 15: System bus, 20: Display screen, 30: Conversion power image, 40: Load

Claims

1. A power calculation device provided in a power supply system that converts first pre-conversion power into first converted power by a first power conversion unit, divides the first converted power, and outputs the divided power to a plurality of first loads, The power supply unit includes an output power calculation unit, a pre-conversion power calculation unit, and a converted power calculation unit, the output power calculation unit calculates a plurality of first output powers to be output to the plurality of first loads, respectively; the pre-conversion power calculation unit calculates, based on a first correlation between the first pre-conversion power and the first post-conversion power and the calculated first output powers, the first pre-conversion power corresponding to the first post-conversion power obtained by adding up the multiple first output powers; the converted power calculation unit calculates a plurality of first converted powers by converting the plurality of first output powers into powers corresponding to the first pre-conversion powers, based on a power ratio between the plurality of first output powers and the calculated first pre-conversion powers; The first load converts second pre-conversion power, which is the first output power obtained by dividing the first converted power, into second converted power by a second power conversion unit, divides the second converted power, and outputs the divided power to each of the second loads; the output power calculation unit calculates a plurality of second output powers to be output to the plurality of second loads, respectively; the pre-conversion power calculation unit calculates, based on a second correlation between the second pre-conversion power and the second post-conversion power and the calculated second output powers, the second pre-conversion power corresponding to the second post-conversion power obtained by adding up the multiple second output powers; the converted power calculation unit calculates a plurality of second converted powers by converting the plurality of second output powers into powers corresponding to the first converted powers, based on a power ratio between the plurality of second output powers and the first converted powers calculated corresponding to the first load; Power calculation device.

2. The power calculation device according to claim 1 , The first correlation is a correlation that takes into account power loss characteristics in the first power conversion unit. Power calculation device.

3. The power calculation device according to claim 1 , A display control unit is further provided, The display control unit causes a display device to distinguishably display the calculated first converted powers. Power calculation device.

4. The power calculation device according to claim 1 , A correlation setting unit is further provided, The correlation setting unit sets the first correlation in accordance with a supply state of power supplied to the first power conversion unit. Power calculation device.

5. A power calculation method executed in a power supply system that converts first pre-conversion power into first converted power by a first power conversion unit, divides the first converted power, and outputs the divided power to a plurality of first loads, The method includes an output power calculation step, a pre-conversion power calculation step, and a converted power calculation step, In the output power calculation step, a plurality of first output powers to be output to the plurality of first loads are calculated, In the pre-conversion power calculation step, the first pre-conversion power corresponding to the first post-conversion power obtained by adding up the first output powers is calculated based on a first correlation between the first pre-conversion power and the first post-conversion power and the calculated first output powers; the converted power calculation step calculates a plurality of first converted powers by converting the plurality of first output powers into powers corresponding to the first pre-conversion powers, based on a power ratio between the plurality of first output powers and the calculated first pre-conversion powers; The first load converts second pre-conversion power, which is the first output power obtained by dividing the first converted power, into second converted power by a second power conversion unit, divides the second converted power, and outputs the divided power to each of the second loads; In the output power calculation step, a plurality of second output powers to be output to the plurality of second loads are calculated, In the pre-conversion power calculation step, the second pre-conversion power corresponding to the second post-conversion power obtained by adding up the plurality of second output powers is calculated based on a second correlation between the second pre-conversion power and the second post-conversion power and the calculated plurality of second output powers; In the converted power calculation step, a plurality of second converted powers are calculated by converting the plurality of second output powers into powers corresponding to the first converted powers, based on a power ratio between the plurality of second output powers and the first converted powers calculated corresponding to the first load. Power calculation method.

6. A power calculation program that causes a processor to execute the power calculation method according to claim 5 .

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