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

Abstract

This invention provides a power calculation device, a power calculation method, and a power calculation program that can accurately determine the power consumption of a load. [Solution] The power calculation device is provided in a power supply system that converts a first pre-conversion power into a first post-conversion power using a first power conversion unit, and divides the first post-conversion power to output to a plurality of first loads. The device comprises 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 a 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 calculated plurality of first output powers. The converted power calculation unit calculates a plurality of first converted powers by converting the plurality of first output powers as power 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 the device side, there is a need to accurately grasp the power consumption for each function (hereinafter also referred to as "load"). Here, accurate power consumption does not refer to the pure power consumption purely consumed by the load, but rather indicates how much of the pure power consumption occupies the power consumption of the power supply source that supplies power to the device, or in other words, 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, it is difficult to determine how much of the pure power consumption of the load occupies the power consumption of the power supply source due to the influence of the power losses, 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-power consumption among the power generation amounts of power consumers equipped with solar power generation facilities.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

[0006] The objective of the present invention is to provide a power calculation device, a power calculation method, and a power calculation program that can accurately determine the power consumption of a load. [Means for solving the problem]

[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 a first pre-conversion power into a first post-conversion power using a first power conversion unit, and divides the first post-conversion power and outputs it to a plurality of first loads, comprising an output power calculation unit, a pre-conversion power calculation unit, and a converted power calculation unit, wherein the output power calculation unit calculates a plurality of first output powers to be output to the plurality of first loads, the pre-conversion power calculation unit calculates the first pre-conversion power based on a first correlation between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers, and the converted power calculation unit calculates a plurality of first converted powers obtained by converting the plurality of first output powers as power 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.

[0008] According to the present invention, multiple first output powers are calculated for each of the multiple first loads, and the first pre-conversion power is calculated based on the first correlation between the first pre-conversion power and the first post-conversion power and the calculated multiple first output powers. As the power corresponding to the first pre-conversion power, multiple first converted powers are calculated by converting each of the multiple first output powers output to each of the multiple first loads, in other words, the power consumed by the multiple first loads upstream of the first power conversion unit in the power supply line (the degree of influence of the power consumption of the multiple first loads on the first pre-conversion power). Therefore, a user who refers to the calculated first converted power can accurately grasp the power consumption of the first loads, taking into account the effect of power loss.

[0009] The following are examples of various embodiments of the present invention. The embodiments shown below can be combined with each other. [2] [1] Power calculation device, wherein the first load converts the second pre-conversion power, which is the first output power obtained by dividing the first converted power, into a second converted power using a second power conversion unit, and divides the second converted power and outputs it to a plurality of second loads, the output power calculation unit calculates a plurality of second output powers to be output to the plurality of second loads, the pre-conversion power calculation unit calculates the second pre-conversion power based on a second correlation between the second pre-conversion power and the second converted power and the calculated plurality of second output powers, and the converted power calculation unit calculates a plurality of second converted powers obtained by converting the plurality of second output powers as power corresponding to the first converted power based on the power ratio between the plurality of second output powers and the first converted power calculated in correspondence with the first load. A power calculation device as described in [3][1], wherein the first correlation is a correlation that takes into account the power loss characteristics in the first power conversion unit. A power calculation device according to any 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. A power calculation device according to any of [5][1] to [4], further comprising a correlation setting unit, wherein the correlation setting unit sets the first correlation according to the supply state supplied to the first power conversion unit. [6] A power calculation method performed in a power supply system that converts a first pre-conversion power into a first post-conversion power by a first power conversion unit, and divides the first post-conversion power and outputs it to a plurality of first loads, comprising an output power calculation step, a first power calculation step, and a converted power calculation step, wherein the output power calculation step calculates a plurality of first output powers to be output to the plurality of first loads, respectively; the pre-conversion power calculation step calculates the first pre-conversion power based on a first correlation between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers; and the converted power calculation step calculates a plurality of first converted powers obtained by converting the plurality of first output powers as power 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. [7] A power calculation program that causes a processor to execute the power calculation method described in [6]. [Effects of the Invention]

[0010] According to the present invention, as the power corresponding to the first pre-conversion power, multiple first converted powers are calculated by converting the multiple first output powers output to each of the multiple first loads, respectively. In other words, the power consumed by the multiple first loads upstream of the first power conversion unit in the power supply path (the degree of influence of the power consumption of the multiple first loads on the first pre-conversion power) is calculated. Therefore, a user who refers to these first converted powers can accurately grasp the power consumption of the loads, taking into account the effects of power loss. [Brief explanation of the drawing]

[0011] [Figure 1] This is a block diagram showing the configuration of power supply system 1. [Figure 2] This is a block diagram showing the hardware configuration of the power calculation device 10. [Figure 3] This is a block diagram showing an example of the functional configuration of the control unit 11 (power calculation device 10). [Figure 4]It is a diagram showing an example of the correlation between the power before the first conversion and the power after the first conversion. [Figure 5] It is an example of a display screen displayed on the display device 5. [Figure 6] It is a flowchart showing an example of the power calculation process performed by the power calculation device 10. [Figure 7] It is a block diagram showing a modified example of the configuration of the power supply system 1. [Figure 8] It is a diagram showing a modified example of the correlation between the power before the first conversion and the power after the first conversion. [Figure 9] It is a diagram showing a modified example of the correlation between the power before the first conversion and the power after the first conversion. [Figure 10] It is a block diagram showing a modified example of the configuration of the power supply system 1.

Embodiments 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 electric 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 100 V system or 200 V system 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, and 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, such as the second power supply source 2A in FIG. 10.

[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 into 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 sensing 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 branching 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 containing 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 sensing 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 branching 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] External devices 7 are peripheral devices that can be connected via USB, such as notebook PCs, tablets, home appliances, smartphones, and storage devices.

[0021] The measurement unit 8 includes, for example, a current sense amplifier, one end of which is connected to the branching point 1a of the first resistor 4 and the second resistor 6 in the power supply line, and the other end of which 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, under the control of the measuring unit 8, switches the connection destination of the other end of the measuring unit 8 between the other end of the first resistor 4 and the other end of the second resistor 6.

[0023] The measuring 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, when the measuring unit 8 controls the switch 9 and switches the connection destination of the other end of the measuring unit 8 to the other end of the first resistor 4 (as shown in Figure 1), it measures the voltage between the first resistor 4 (specifically, between one end and the other end of the measuring unit 8) to measure the current flowing through the first resistor 4 and, consequently, the current flowing through the display device 5. The measuring unit 8 then outputs first current information indicating the current value of the current flowing through the display device 5 to the power calculation device 10. The measuring unit 8 may also measure the current flowing through the display device 5 using, for example, a magnetic field detection type current sensor IC, instead of using the first resistor 4.

[0024] Furthermore, the measurement unit 8 controls the switch 9 to switch the connection destination of the other end of the measurement unit 8 to the other end of the second resistor unit 6, and measures the voltage between the second resistor unit 6 (specifically, between one end and the other end of the measurement unit 8) to measure the current flowing through the second resistor unit 6 and, consequently, the current flowing through the external device 7. The measurement unit 8 then 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 also measure the current flowing through the external device 7 using, for example, a magnetic field detection type current sensor IC, instead of using the second resistor unit 6.

[0025] The power supply system 1 may also be equipped with two measuring units instead of the measuring unit 8 and the switch 9, each measuring the current flowing through the first resistor 4 and the current flowing through the second resistor 6. However, compared to the case where two measuring units are provided, it is preferable that the measuring 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, in order to reduce the circuit cost of the measuring circuit by combining the measuring circuits for measuring the currents flowing through the first resistor 4 and the second resistor 6 into one.

[0026] The power calculation device 10 is, for example, a microcontroller, and is configured to allow the user to accurately determine the power consumption of multiple first loads (in this embodiment, the display device 5 and external devices 7) installed in the power supply path of the power supply system 1.

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

[0028] The control unit 11 is, for example, a CPU (Central Processing Unit), a microprocessor, a DSP (Digital Signal Processor), and controls the overall operation of the power calculation device 10. The control unit 11 may be composed of various circuits such as ASICs (Application-Specific Integrated Circuits) and FPGAs (Programmable Logic Devices), or it may be composed of a combination of a processor and circuits.

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

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

[0031] The programs stored in the memory unit 12 include, for example, an OS (Operating System) for realizing the basic functions of the power calculation device 10, drivers for controlling various hardware, and programs for realizing various functions, 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 the function of connecting to a communication line (not shown). Alternatively, the communication unit 13 may have functions to connect to a wireless LAN (Local Area Network), a wireless WAN (Wide Area Network), short-range wireless communication such as Bluetooth®, wired communication such as USB, and infrared communication, either in place of or in conjunction with the NIC. The power calculation device 10 is connected to the display device 5, etc., via the communication line and can send and receive various types of data between it and the display device 5, etc.

[0033] The operation input unit 14 consists of, for example, a keyboard, mouse, touch panel, switch, etc., and accepts input of various operations from the user using the power calculation device 10.

[0034] The control unit 11, storage unit 12, communication unit 13, and operation input unit 14 are electrically connected to each other via the system bus 15. Therefore, the control unit 11 can access the storage unit 12, understand the user's operation status of the operation input unit 14, and access various communication networks and display devices 5, etc., via the communication unit 13.

[0035] Figure 3 is a block diagram showing an example of the functional configuration of the control unit 11 of the power calculation device 10 in this embodiment. As shown in Figure 3, the control unit 11 has the functional configuration of 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 setting unit 11e. In general, the control unit 11 of the power calculation device 10 has various other functions besides those described above, but here we will only describe the functions that are characteristic in that they determine the power consumption of a plurality of first loads (display device 5, external equipment 7) installed in the power supply path of the power supply system 1, and other known functions will not be shown or described.

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

[0037] The pre-conversion power calculation unit 11b calculates the first pre-conversion power based on the first correlation 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 external equipment 7 calculated by the output power calculation unit 11a (corresponding to the first post-conversion power, which is the sum of the first output power to the display device 5 and external equipment 7).

[0038] The first correlation is a correlation that takes into account, for example, the power loss characteristics in the first power conversion unit 3 (including, for example, nonlinear or linear conversion efficiency characteristics such as AC / DC converters and DC / DC converters, and power loss characteristics due to a predetermined load such as a resistive circuit). The first correlation can be determined by experiments or other methods 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] Figure 4 shows an example of the first correlation between the first pre-conversion power and the first post-conversion power. As shown in Figure 4, the first correlation between the first pre-conversion power and the first post-conversion power is expressed by a nonlinear quadratic equation L1. For example, if the first post-conversion power (the sum of the first output power to the display device 5 and the external device 7) is 80W, the first pre-conversion power can be calculated as 90W via the nonlinear quadratic equation L1. In this case, the ratio of the first pre-conversion power to the first post-conversion power is 1.125:1. Also, if the first post-conversion power is 46W, the first pre-conversion power can be calculated as 56.6W via the nonlinear quadratic equation L1. In this case, the ratio of the first pre-conversion power to the first post-conversion power is approximately 1.23:1. That is, when the first post-conversion power is 80W, the ratio of the first pre-conversion power to the first post-conversion power is smaller (not constant) compared to when the first post-conversion power is 46W. Correlation information showing the first correlation between the first power before conversion and the first power after conversion is stored in the storage unit 12 in the form of a table or an approximation formula.

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

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

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

[0043]

number

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

[0045]

number

[0046] The display control unit 11d outputs image data to the display device 5 showing 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 the first converted power of at least one of the display device 5 and the external device 7 in an identifiable manner (for example, on-screen display). In addition to the first converted power of the display device 5 and the external device 7, the display control unit 11d may also display at least one of the powers obtained in the process of calculating the first converted power of the display device 5 and the external device 7, such as the first output power output to the display device 5, the first output power output to the external device 7, the first power before conversion, and the first power after conversion, on the display device 5.

[0047] Figure 5 shows an example of the display screen 20 displayed on the display device 5. As shown in Figure 5, the upper left portion of the display screen 20 shows a converted power image 30 using icons for the display device 5 and the external device 7, indicating that the first converted power of the display device 5 is 6W and the first converted power of the external device 7 is 54W. By referring to the converted power image 30, a user can accurately grasp the power consumption of the first load (display device 5 and external device 7), taking into account the effect of power loss by the first power conversion unit 3.

[0048] Furthermore, on the display screen 20, the converted power image 30 may be displayed in the upper right, lower left, or lower right portion instead of the upper left portion, or in a portion selected by the user from among multiple portions. In addition, from the viewpoint of preventing 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 transparency of the converted power image 30 displayed on the display screen 20 may be arbitrarily changed by the user.

[0049] The correlation setting unit 11e sets a first correlation that the pre-conversion power calculation unit 11b refers to, according to the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 (corresponding to the "supply state" in this invention). For example, the correlation setting unit 11e sets a correlation that is designed to optimize the calculation accuracy of the first pre-conversion power corresponding to the first converted power when the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 is 100V, as the first correlation that the pre-conversion power calculation unit 11b refers to. Alternatively, the correlation setting unit 11e sets a correlation that is designed to optimize the calculation accuracy of the first pre-conversion power corresponding to the first converted power when the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3 is 200V, as the first correlation that the pre-conversion power calculation unit 11b refers to. As a result, even if the supply voltage supplied from the first power source 2 to the first power conversion unit 3 is changed, the optimal first correlation relationship is set taking that change into consideration, thereby maintaining optimal accuracy in calculating the first pre-conversion power.

[0050] Furthermore, the correlation setting unit 11e may automatically set the first correlation that the pre-conversion power calculation unit 11b references, according to the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3. Also, when a user gives a switching instruction, the correlation setting unit 11e may switch and set the first correlation according to the supply voltage supplied from the first power supply source 2 to the first power conversion unit 3. In addition, the correlation setting unit 11e may set the first correlation that the pre-conversion power calculation unit 11b references, according to whether power is supplied to the first power supply source 2 by, for example, USB PD power supply, AC input, DC input, or battery power supply (corresponding to the "supply state" of the present invention).

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

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

[0053] Next, the pre-conversion power calculation unit 11b calculates the first post-conversion power after conversion by the first power conversion unit 3 by summing the first output power to the display device 5 and 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 (step S120) based on the first correlation 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 after conversion by the first power conversion unit 3, and the first post-conversion power calculated in step S110 (the sum of the first output power to the display device 5 and the external device 7).

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

[0056] Finally, the display control unit 11d outputs image data showing the first converted power 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 converted power of the display device 5 and the external device 7 in an identifiable manner (step S140). Upon completion of the process in step S140, the power calculation device 10 terminates the power calculation process shown in Figure 6.

[0057] As explained in detail above, in this embodiment, the power calculation device 10 is provided in a power supply system 1 that converts the first pre-conversion power into the first post-conversion power using the first power conversion unit 3, and divides the first post-conversion power to output to a plurality of first loads (display device 5 and external equipment 7). The power calculation device 10 comprises an output power calculation unit 11a, a pre-conversion power calculation unit 11b, and a converted power calculation unit 11c. The output power calculation unit 11a calculates a plurality of first output powers to be output to a plurality of first loads. The pre-conversion power calculation unit 11b calculates the first pre-conversion power based on a first correlation between the first pre-conversion power and the first post-conversion power, and a plurality of first output powers (summed power) calculated by the output power calculation unit 11a. The converted power calculation unit 11c calculates multiple first converted powers by converting each of the multiple first output powers as power corresponding to the first pre-conversion power, based on the power ratio between the multiple first output powers and the first pre-conversion power calculated by the pre-conversion power calculation unit 11b.

[0058] According to this embodiment, which is configured in this way, the power corresponding to the first pre-conversion power is calculated by converting each of the multiple first output powers output to each of the multiple first loads (display device 5 and external device 7). In other words, the power consumed by the multiple first loads upstream of the first power conversion unit 3 in the power supply path of the power supply system 1 is calculated. Therefore, a user who refers to this first converted power can accurately grasp the power consumption of the first loads (display device 5 and external device 7) while taking into account the effect of power loss by the first power conversion unit 3.

[0059] In the above embodiment, an example was described in which the display device 5 and the external device 7 function as the "multiple first loads" of the present invention, but the present invention is not limited to this. For example, instead of two devices, three or more devices may function as the "multiple first loads" of the present invention, or one device and a group of devices including two or more devices may function as the "multiple first loads" of the present invention.

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

[0061] Figure 7 is a block diagram showing a modified configuration of the power supply system 1. As shown in Figure 7, the first resistor 4 is a current sensing resistor (shunt resistor) provided between the first power conversion unit 3 and the branching point 1a in the power supply path of the power supply system 1. The branching point 1a is the point where the power supply path 1b, which divides the first converted power converted by the first power conversion unit 3 and outputs it to the display device 5, and the power supply path 1c, which divides the first converted power converted by the power conversion unit 3 and outputs it to an external device 7, diverge. One end of the first resistor 4 is connected to the first power conversion unit 3, and the other end of the first resistor 4 is connected to the branching point 1a.

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

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

[0064] The measuring 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, when the measuring unit 8 controls the switch 9 and switches the connection destination of the other end of the measuring unit 8 to the other end of the first resistor 4 (as shown in Figure 7), it measures the current flowing through the first resistor 4 by measuring the voltage between the first resistor 4 (specifically, between one end and the other end of the measuring unit 8). The measuring unit 8 then outputs first current information, which indicates the current value of the current flowing through the first resistor 4, to the power calculation device 10.

[0065] Furthermore, the measuring unit 8 controls the switch 9 to switch the connection destination of the other end of the measuring unit 8 to the other end of the second resistor 6, and measures the voltage between the second resistor 6 (specifically, between one end and the other end of the measuring unit 8) to measure the current flowing through the second resistor 6 and, consequently, the current flowing through the display device 5. The measuring unit 8 then outputs second current information, which indicates 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 calculates the first converted power (for example, 40W) supplied after conversion by the first power conversion unit 3 by multiplying the current value (current value of the current flowing through the first resistor unit 4) indicated in the first current information output from the measurement unit 8 by the output voltage of the first power conversion unit 3. The output power calculation unit 11a also calculates the power consumed by the display device 5 (for example, 5W) as the first output power output to the display device 5 by multiplying the current value (current value of the current flowing through the display device 5) indicated in the second current information output from the measurement unit 8 by the voltage supplied to the display device 5. After calculating the first converted power (for example, 40W) supplied after conversion by the first power conversion unit 3 and the first output power output to the display device 5 (for example, 5W), the output power calculation unit 11a calculates the first output power (for example, 35W) output to the external device 7 by subtracting the first output power from the first converted power.

[0067] Furthermore, in the above embodiment, the first correlation 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 Figure 4. Figure 8 shows a modified example of the first correlation between the first pre-conversion power and the first post-conversion power. As shown in Figure 8, the first correlation between the first pre-conversion power and the first post-conversion power is expressed by a linear linear equation L2. For example, if the first post-conversion power is 50W, the first pre-conversion power can be calculated as 60W via the linear linear equation L2. For example, suppose the output power calculation unit 11a calculates the power consumed by the display device 5 (e.g., 5W) 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.

[0068] In this case, the pre-conversion power calculation unit 11b calculates the first pre-conversion power (for example, 60W) based on the first correlation (for example, the first correlation shown in Figure 8) 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 supplied after conversion by the first power conversion unit 3, and the first output power to the display device 5 and external device 7 calculated by the output power calculation unit 11a (corresponding to the first converted power, which is the sum of the first output power to the display device 5 and external device 7, for example, 50W).

[0069] The converted power calculation unit 11c calculates two first converted powers (e.g., display device 5: 6W, external device 7: 54W) by converting the two first output powers (e.g., display device 5: 5W, external device 7: 45W) respectively as power corresponding to the first pre-conversion power (e.g., 60W), 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., 5W: 45W = 1:9) and the first pre-conversion power calculated by the pre-conversion power calculation unit 11b (e.g., 60W).

[0070] Figure 9 shows a modified example of the first correlation between the first pre-conversion power and the first post-conversion power. As shown in Figure 9, the first correlation between the first pre-conversion power and the first post-conversion power is expressed by a linear linear equation L3. For example, if the first post-conversion power is 80W, the first pre-conversion power can be calculated as 100W via the linear linear equation L3.

[0071] Furthermore, in the above embodiment, an example was described in which the power calculation process performed by the power calculation device 10 is executed, for example, every predetermined time, 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 in the normal operating state, the output power calculation unit 11a calculates the power consumed by the display device 5 (for example, 35W) as the first output power output to the display device 5, and calculates the power consumed by the external device 7 (for example, 45W) as the first output power output to the external device 7.

[0072] In this case, the pre-conversion power calculation unit 11b calculates the first pre-conversion power (for example, 90W) based on the first correlation (for example, the first correlation shown in Figure 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 converted power supplied after conversion by the first power conversion unit 3, and the first output power to the display device 5 and external device 7 calculated by the output power calculation unit 11a (corresponding to the first converted power, which is the sum of the first output power to the display device 5 and external device 7, for example, 80W).

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

[0074] Furthermore, if the operating state of the display device 5 is in standby mode, the output power calculation unit 11a calculates the power consumed by the display device 5 (for example, 1W) as the first output power output to the display device 5, and calculates the power consumed by the external device 7 (for example, 45W) as the first output power output to the external device 7.

[0075] In this case, the pre-conversion power calculation unit 11b calculates the first pre-conversion power (for example, 56.6W) based on the first correlation (for example, the correlation shown in Figure 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 to the display device 5 and external device 7 calculated by the output power calculation unit 11a (corresponding to the first post-conversion power, which is the sum of the first output power to the display device 5 and external device 7, for example, 46W).

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

[0077] As described above, the first output power (e.g., 45W) output to the external device 7 remains constant regardless of the operating state of the display device 5 (normal operation state, standby state). However, if the first output power, and therefore the first converted power, output to the display device 5 changes from, for example, 80W to 46W in response to a change in the operating state of the display device 5, the first pre-conversion power also changes from, for example, 90W to 56.6W according to the first correlation. Therefore, even if the first output power output to the external device 7 remains constant (e.g., 45W), the first converted power (normal operation state: 50.625W, standby state: 55.37W), which is calculated by converting the first output power to the external device 7 as the power corresponding to the first pre-conversion power, changes, as does the degree of influence of the power consumption of the external device 7 on the first pre-conversion power. Furthermore, the first power before conversion is lower in the standby state (e.g., 56.6W) than in the normal operating state (e.g., 90W), but the first converted power, which is calculated by converting the first output power to the external device 7, is higher in the standby state (e.g., 55.37W) than in the normal operating state (e.g., 50.625W). In this way, it is possible to accurately grasp the change in power consumption of the external device 7, taking into account the effect of power loss by the first power conversion unit 3.

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

[0079] The first power conversion unit 3 is, for example, an AC / DC converter, which converts the AC power (first pre-conversion power) supplied from the first power supply source 2 to generate DC power (first post-conversion power), and divides the generated DC power to supply to the display device 5 and the load 40. The second power supply source 2A of the load 40 supplies the DC power (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 (second pre-conversion power) supplied from the second power supply source 2A to second post-conversion power, and divides the second post-conversion power to output to the first external device 7A and the second external device 7B as DC power (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 and output to the display device 5, in the same manner as the power calculation method described in the above embodiment. The control unit 11 also 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 conversion by the second power conversion unit 3A.

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

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

[0083] The control unit 11 calculates two first converted powers by converting the first output power to the display device 5 and the load 40 as the power corresponding to the first pre-conversion power, 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. Then, the control unit 11 calculates two second converted powers by converting the second output power to the first external device 7A and the second external device 7B as the power corresponding to the first converted power, based on the power ratio between the second output power to the first external device 7A and the second external device 7B and the first converted power calculated in relation to the load 40. In this way, by using the first converted power calculated in accordance with the load 40 to determine the second converted power of the first external device 7A and the second external device 7B, the power consumed by the two loads (first external device 7A and second external device 7B) upstream of the first power conversion unit 3, which is located upstream of the second power conversion unit 3A in the power supply path of the power supply system 1, is calculated, 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. The control unit 11 may also display image data showing at least one of the calculated first converted power and second converted power in an identifiable manner. Furthermore, the control unit 11 may set a first correlation and a second correlation 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, three converted powers (first converted power, second converted power) are calculated by converting the three output powers (first output power, second output power) output to the three loads (display device 5, first external device 7A, and second external device 7B), respectively, as the power corresponding to the first pre-conversion power. In other words, the power consumed by the three loads upstream of the first power conversion unit 3 in the power supply path of the power supply system 1 (the influence of the power consumption of the three loads on the first pre-conversion power) is calculated. Therefore, a user who refers to these converted powers can accurately grasp the power consumption of the loads (display device 5, first external device 7A, and second external device 7B) while taking into account the effects of power loss by the first power conversion unit 3 and the second power conversion unit 3A.

[0085] Although various embodiments of the present invention have been described above, these are presented as examples only and are not intended to limit the scope of the invention. These novel embodiments can be implemented in a variety of other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of Symbols]

[0086] 1: Power supply system, 1a: Branch point, 1b, 1c: Power supply path, 2: First power supply source, 2A: Second power supply source, 3: First power conversion unit, 3A: Second power conversion unit, 4: First resistor unit, 5: Display device, 6: Second resistor 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: Converted power calculation unit, 11d: Display control unit, 11e: Correlation setting unit, 12: Memory unit, 13: Communication unit, 14: Operation input unit, 15: System bus, 20: Display screen, 30: Converted power image, 40: Load

Claims

1. A power calculation device provided in a power supply system that converts a first pre-conversion power into a first post-conversion power by a first power conversion unit, and divides the first post-conversion power and outputs it to a plurality of first loads, It comprises 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 that are output to each of the plurality of first loads, The pre-conversion power calculation unit calculates the first pre-conversion power based on the first correlation between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers. The converted power calculation unit calculates a plurality of first converted powers by converting each of the plurality of first output powers as power 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. Power calculation device.

2. A power calculation device according to claim 1, The first load divides the first converted power and outputs the second pre-conversion power, which is the first output power, and the second power conversion unit converts this second converted power into a second converted power, and divides the second converted power and outputs it to a plurality of second loads, The output power calculation unit calculates a plurality of second output powers that are output to each of the plurality of second loads, The pre-conversion power calculation unit calculates the second pre-conversion power based on the second correlation 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 by converting each of the plurality of second output powers as power corresponding to the first converted power, based on the power ratio between the plurality of second output powers and the first converted power calculated in accordance with the first load. Power calculation device.

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

4. A power calculation device according to claim 1, It further includes a display control unit, The display control unit causes the display device to display the calculated plurality of first converted powers in an identifiable manner. Power calculation device.

5. A power calculation device according to claim 1, It further includes a correlation setting unit, The correlation setting unit sets the first correlation according to the supply state supplied to the first power conversion unit. Power calculation device.

6. A power calculation method performed in a power supply system that converts a first pre-conversion power into a first post-conversion power by a first power conversion unit, and divides the first post-conversion power and outputs it to a plurality of first loads, wherein The system comprises an output power calculation step, a pre-conversion power calculation step, and a converted power calculation step, In the output power calculation step, the multiple first output powers output to each of the multiple first loads are calculated, In the pre-conversion power calculation step, the first pre-conversion power is calculated based on the first correlation between the first pre-conversion power and the first post-conversion power and the calculated plurality of first output powers. In the converted power calculation step, a plurality of first converted powers are calculated by converting each of the plurality of first output powers as power 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. Power calculation method.

7. A power calculation program that causes a processor to execute the power calculation method described in claim 6.

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