Power System
Patent Information
- Application Number
- JP2023565433
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- Filing Date
- 2023-05-30
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2043-05-30
AI Technical Summary
Existing power supply systems with multiple capacitors and discharge resistors require a large number of parts, leading to high failure rates and manufacturing costs, particularly in systems with multiple power supplies.
A power supply system with multiple power supplies, each equipped with a single capacitor, resistor, and a life calculation unit that measures voltage and temperature to determine capacitor lifespan, allowing for efficient management of capacitor life while reducing the number of components.
The system effectively manages capacitor life across multiple power supplies, reducing parts and maintaining reliable power supply by extending capacitor lifespan through controlled current output.
Smart Images
Figure 00000007_0000 
Figure 00000007_0001 
Figure 00000007_0002
Abstract
Description
[Technical field]
[0001] The present disclosure relates to a power supply system. [Background technology]
[0002] Power supplies contain capacitors to smooth the current. Power supplies are required to operate for a long period of time, but because capacitors are limited-life components, managing the lifespan of capacitors is important in managing power supplies.
[0003] Patent Document 1 discloses a power supply device that has multiple capacitors, switches the electrical connection of the capacitors using a switching element, and calculates the capacitor's life based on the voltage value of a discharge resistor connected in parallel across the capacitors during discharge. [Prior art documents] [Patent documents]
[0004] [Patent Document 1] International Publication No. 2008 / 016050 Summary of the Invention [Problem to be solved by the invention]
[0005] Because the supply of power from power supplies is important for the operation of equipment, supplying power from a multiplexed power supply system made up of multiple power supplies is more reliable than supplying power from a single power supply.
[0006] On the other hand, the power supply device described in Patent Document 1 has a problem that a single device includes multiple capacitors, multiple discharge resistors, multiple switches, etc., and also requires a microcomputer, resulting in a large number of parts, which increases the failure rate and manufacturing costs. These problems become more pronounced in a power supply system that requires multiple power supply devices.
[0007] In consideration of the above circumstances, an object of the present disclosure is to provide a power supply system multiplexed with multiple power supply devices, which can manage the lifespan of the capacitors of each power supply device while reducing the number of parts in each power supply device. [Means for solving the problem]
[0008] In order to achieve the above object, the power supply system according to the present disclosure comprises: A plurality of power supplies are provided, Each of the plurality of power supply devices a first line connected to one end of the load; a second line connected to the other end of the load; A switch having one end connected to the first line; a capacitor having one end connected to the other end of the switch and the other end connected to the second line, smoothing the power supplied to the load by the first line and the second line; A resistor connected in parallel with the capacitor; a voltage measuring means for measuring a voltage value between both ends of the resistor; A temperature measuring means for measuring the temperature of the capacitor; A capacitance of the capacitor is calculated based on a voltage value between both ends of the resistor measured by the voltage value measuring means and a resistance value of the resistor when the switch is off, and the calculated capacitance of the capacitor and the temperature of the capacitor measured by the temperature measuring means are used. The life characteristics of the capacitor A life calculation means for calculating a life of the capacitor based on the Equipped with Each of the plurality of power supply devices includes only one capacitor for smoothing the power supplied to the load. Effect of the Invention
[0009] In a power supply system multiplexed with a plurality of power supply devices, the number of parts in each power supply device can be reduced while managing the lifespan of the capacitors in each power supply device. [Brief description of the drawings]
[0010] [Figure 1] FIG. 1 is a diagram showing an overall configuration of a power supply system according to an embodiment of the present disclosure. [Diagram 2] FIG. 1 is a diagram showing an example of a life characteristic of a capacitor included in each power supply device of a power supply system according to an embodiment of the present disclosure. [Diagram 3] FIG. 1 is a diagram showing an overall configuration of a power supply system according to a modified example of an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0011] Hereinafter, a power supply system according to an embodiment of the present disclosure will be described with reference to the drawings. In each drawing, the same or equivalent parts are denoted by the same reference numerals.
[0012] (Embodiment) A power supply system 1 according to an embodiment will be described with reference to FIG. 1. The power supply system 1 includes a plurality of power supply devices 10 and a control unit 20. Each power supply device 10 is connected to a load 2 and supplies power to the load 2. Each power supply device 10 is communicably connected to the control unit 20. As described below, the power supply system 1 has the following functions. Each power supply device 10 has a function of calculating the life of the capacitor 103 included in the power supply device 10. The control unit 20 controls the switching control circuit 108 of each power supply device 10 based on the life of the capacitor 103 calculated by each power supply device 10, and controls the current output from each power supply device 10 according to the life of the capacitor 103. Although two power supply devices 10 are shown in FIG. 1, the number of power supply devices 10 may be three or more. The power supply system 1 is an example of a power supply system according to the present disclosure.
[0013] The power supply device 10 is a power supply device that converts AC power into DC power by switching control and supplies it to a load 2. The power supply device 10 includes a line L1, a line L2, a transformer 101, a switch 102, a capacitor 103, a resistor 104, a temperature measurement unit 105, a voltage value measurement unit 106, a life calculation unit 107, a switching control circuit 108, and an output current measurement unit 109. In the case shown in FIG. 1, the left side of the transformer 101 is the primary side, and the right side is the secondary side. In FIG. 1, the description of the primary side is omitted except for the switching control circuit 108. In the following description, the description of the primary side is omitted except for the switching control circuit 108. The power supply device 10 is an example of a power supply device according to the present disclosure.
[0014] The line L1 is connected to one end of the load 2, and the line L2 is connected to the other end of the load 2. DC power is supplied to the load 2 via the line L1 and the line L2. The line L1 is an example of a first line according to the present disclosure. The line L2 is an example of a second line according to the present disclosure.
[0015] The transformer 101 transforms the power supplied from the primary side and supplies it to the secondary side.
[0016] One end of the switch 102 is connected to the line L1, and the other end is connected to the capacitor 103 and the resistor 104. As described later, when the switch 102 is off, the power supply to the load 2 by the power supply device 10 is stopped, but the life calculation unit 107 can calculate the life of the capacitor 103. Since the power supply system 1 includes a plurality of power supply devices 10, the power supply to the load 2 can be continued unless all the power supply devices 10 simultaneously stop supplying power to the load 2. The switch 102 may be a switch that can be manually switched on and off, or may be a switch that can be controlled by an electric signal and is automatically turned off for a short period of time at regular intervals to calculate the life. The switch that can be controlled by an electric signal is a relay, a transistor, or the like. The switch 102 is an example of a switch according to the present disclosure.
[0017] One end of the capacitor 103 is connected to the switch 102, and the other end is connected to the line L2. The capacitor 103 smoothes the power transformed by the transformer 101. The capacitor 103 is, for example, an aluminum electrolytic capacitor. In general, as the time of use of a capacitor increases, the capacitor deteriorates and the capacitance of the capacitor decreases. According to the Arrhenius law, the higher the temperature of the capacitor, the shorter the life of the capacitor. In the power supply device 10, the higher the current flowing through the line L1, the higher the temperature of the capacitor 103. A life calculation unit 107 described later calculates the life of the capacitor 103 based on the capacitance and temperature of the capacitor 103. The capacitance of the capacitor 103 when not in use is known. This capacitance of the capacitor 103 when not in use is used when the life calculation unit 107 calculates the life of the capacitor 103. The capacitor 103 is an example of a capacitor according to the present disclosure.
[0018] The resistor 104 is connected in parallel with the capacitor 103. When the switch 102 is off, the resistor 104 discharges the charge accumulated in the capacitor 103. The resistance value of the resistor 104 is known. This resistance value is used when a lifetime calculation unit 107, which will be described later, calculates the capacitance of the capacitor 103. The resistor 104 is an example of a resistor according to the present disclosure.
[0019] The temperature measuring unit 105 measures the temperature of the capacitor 103. The temperature measuring unit 105 is realized by, for example, a thermistor. The temperature measuring unit 105 outputs information indicating the measured temperature of the capacitor 103 to the lifetime calculating unit 107. The temperature measuring unit 105 is an example of a temperature measuring means according to the present disclosure.
[0020] The voltage value measuring unit 106 measures the voltage value between both ends of the resistor 104. The voltage value measuring unit 106 is realized by, for example, an A / D (Analog to Digital) converter. The voltage value measuring unit 106 outputs information indicating the measured voltage value between both ends of the resistor 104 to the life calculation unit 107. Since the resistor 104 is connected in parallel to the capacitor 103, the voltage value measured by the voltage value measuring unit 106 is also the voltage value between both ends of the capacitor 103. The voltage value measuring unit 106 is an example of a voltage value measuring means according to the present disclosure.
[0021] The life calculation unit 107 calculates the capacitance of the capacitor 103 based on the voltage value between both ends of the resistor 104 measured by the voltage value measurement unit 106 when the switch 102 is off and the known resistance value of the resistor 104. The life calculation unit 107 then calculates the life of the capacitor 103 based on the calculated capacitance of the capacitor 103 and the temperature of the capacitor 103 measured by the temperature measurement unit 105. The life calculation unit 107 outputs information indicating the calculated life to a current control unit 201 of the control unit 20 described later. The life calculation unit 107 is realized by, for example, a microcontroller. The life calculation unit 107 may also be integrated with the voltage value measurement unit 106 realized by the A / D converter described above. The life calculation unit 107 is an example of a life calculation means according to the present disclosure.
[0022] The calculation of the capacitance of capacitor 103 will be described in more detail. When switch 102 is turned off, discharging by resistor 104 begins. This discharge gradually releases the charge accumulated in capacitor 103, and the voltage value across capacitor 103, i.e., the voltage value across resistor 104, gradually decreases. If the voltage value across capacitor 103 at the start of discharge is V1, the voltage value across capacitor 103 when time T has elapsed since the start of discharge is V2, and the resistance value of resistor 104 is R, then the capacitance C of capacitor 103 can be calculated based on the following formula (1), where ln is a logarithmic function with the natural logarithm as the base. C = T / (R × ln(V1 / V2)) (1)
[0023] The life calculation unit 107 calculates the capacitance of the capacitor 103 based on the formula (1).
[0024] The life characteristic of the capacitor 103 is shown, for example, in a graph as shown in FIG. 2. The life of the capacitor 103 is determined to be when the capacitance of the capacitor 103 reaches a predetermined capacitance. For example, when the capacitance of the capacitor 103 becomes 80% of the capacitance when the capacitor 103 is not in use, the life of the capacitor 103 is exhausted. The life characteristic of the capacitor varies depending on the temperature of the capacitor 103. Specifically, according to Arrhenius' law, the higher the temperature of the capacitor 103, the shorter the time required to reach the end of its life. The life calculation unit 107 holds data related to the life characteristic shown in FIG. 2, and calculates the life of the capacitor 103 based on the data, the capacitance of the capacitor 103 calculated based on formula (1), and the temperature of the capacitor 103 measured by the temperature measurement unit 105.
[0025] The switching control circuit 108 adjusts the supplied AC power on the primary side by switching control, and controls the current output to the load 2. The switching control circuit 108 operates based on the control by a current control unit 201 of the control unit 20 described below. The switching control circuit 108 is an example of a switching control circuit according to the present disclosure.
[0026] The output current measuring unit 109 measures the current value of the current output to the line L1. The output current measuring unit 109 is communicatively connected to a current control unit 201 of the control unit 20 described later via a wire not shown. The output current measuring unit 109 outputs a signal indicating the measured current value to the current control unit 201. The measured current value is used for current control by the current control unit 201. When the life calculation unit 107 is realized by a microcontroller as described above, the output current measuring unit 109 may be communicatively connected to the microcontroller instead of the current control unit 201. In this case, the output current measuring unit 109 outputs a signal indicating the measured current value to the microcontroller, and the microcontroller outputs a signal indicating the current value to the current control unit 201. The output current measuring unit 109 is realized by, for example, a current sensor equipped with a Hall element.
[0027] The control unit 20 includes a current control unit 201. The current control unit 201 is communicatively connected to the life calculation unit 107 and the switching control circuit 108 of each power supply device 10. When the output current measurement unit 109 of each power supply device 10 is connected to the current control unit 201, the current control unit 201 receives a signal indicating the measured current value from the output current measurement unit 109. When the output current measurement unit 109 of each power supply device 10 is connected to a microcontroller that realizes the life calculation unit 107, the current control unit 201 receives a signal indicating the measured current value from the microcontroller. For each power supply device 10, the current control unit 201 controls the switching control circuit 108 based on the life of the capacitor 103 calculated by the life calculation unit 107 and a signal indicating the current value measured by the output current measurement unit 109. For example, for a power supply device 10 in which the life of the capacitor 103 is short, the current control unit 201 controls the switching circuit 108 so that the current output to the load 2 is reduced. This control makes it possible to suppress a rise in temperature of the capacitor 103, thereby making it possible to extend the life of the capacitor 103.
[0028] The power supply system 1 according to the embodiment has been described above. Each power supply device 10 can calculate the life of the capacitor 103 by turning off the switch 102. Since the power supply system 1 includes a plurality of power supply devices 10, as long as all of the power supply devices 10 are not stopped, power supply to the load 2 can be continued even if there is a power supply device 10 whose switch 102 is turned off.
[0029] Furthermore, since the current control section 201 of the control unit 20 can control the current for each power supply device 10 according to the life of the capacitor 103, the life of the capacitor 103 of each power supply device 10 can be extended.
[0030] Furthermore, since each power supply device 10 only needs to have one switch 102, one capacitor 103, and one resistor 104, the number of parts in each power supply device can be reduced. Therefore, in a power supply system multiplexed with a plurality of power supply devices, the power supply system 1 can manage the lifespan of the capacitors in each power supply device while reducing the number of parts in each power supply device.
[0031] (Variation 1) In the embodiment, each power supply device 10 includes the life calculation unit 107. Alternatively, as shown in FIG. 3, the control unit 20 may include the life calculation unit 202, and the temperature measurement unit 105 and the voltage value measurement unit 106 of each power supply device 10 may output information to the life calculation unit 202. The life calculation unit 202 calculates the capacitance of the capacitor 103 for each power supply device 10 based on the voltage value between both ends of the resistor 104 measured by the voltage value measurement unit 106 and the resistance value of the resistor 104, and calculates the life of the capacitor 103 based on the calculated capacitance of the capacitor 103 and the temperature of the capacitor 103 measured by the temperature measurement unit 105. The life calculation unit 202 outputs information indicating the calculated life of the capacitor 103 of each power supply device 10 to the current control unit 201. This eliminates the need for the life calculation unit 107 in each power supply device 10, and only one life calculation unit 202 is required for one control unit, thereby further reducing the number of parts. The lifespan calculation unit 202 is an example of a lifespan calculation means according to the present disclosure.
[0032] (Variation 2) The current control section 201 of the control unit 20 may refer to schedule data relating to the operation of the power supply system 1 and control the switching control circuit 108 so that the capacitor 103 does not expire on dates when maintenance of the power supply system 1 is not possible. For example, the control unit 20 may be provided with a storage section that stores calendar data, and the current control section 201 may refer to the calendar data stored in the storage section and control the switching control circuit 108 of each power supply device 10 so that the capacitor 103 does not expire during long holidays when maintenance is considered impossible.
[0033] Various embodiments and modifications of the present disclosure are possible without departing from the broad spirit and scope of the present disclosure. The above-described embodiments are for explaining the present disclosure and do not limit the scope of the present disclosure. In other words, the scope of the present disclosure is indicated by the claims, not the embodiments. Various modifications made within the scope of the claims and within the scope of the disclosure equivalent thereto are considered to be within the scope of the present disclosure. [Explanation of symbols]
[0034] 1 power supply system, 2 load, 10 power supply device, 20 control unit, 101 transformer, 102 switch, 103 capacitor, 104 resistor, 105 temperature measurement section, 106 voltage value measurement section, 107 life calculation section, 108 switching control circuit, 109 output current measurement section, 201 current control section, 202 life calculation section, L1, L2 lines.
Claims
1. A plurality of power supplies are provided, Each of the plurality of power supply devices a first line connected to one end of the load; a second line connected to the other end of the load; A switch having one end connected to the first line; a capacitor having one end connected to the other end of the switch and the other end connected to the second line, smoothing the power supplied to the load by the first line and the second line; A resistor connected in parallel with the capacitor; a voltage measuring means for measuring a voltage value between both ends of the resistor; A temperature measuring means for measuring the temperature of the capacitor; a life calculation means for calculating a capacitance of the capacitor based on a voltage value between both ends of the resistor and a resistance value of the resistor measured by the voltage value measurement means while the switch is off, and for calculating a life of the capacitor based on the calculated capacitance of the capacitor and a temperature of the capacitor measured by the temperature measurement means; Equipped with Each of the plurality of power supply devices includes only one capacitor that smoothes power supplied to the load. Power supply system.
2. A power supply device and a life calculation means are provided, Each of the plurality of power supply devices a first line connected to one end of the load; a second line connected to the other end of the load; A switch having one end connected to the first line; a capacitor having one end connected to the other end of the switch and the other end connected to the second line, smoothing the power supplied to the load by the first line and the second line; A resistor connected in parallel with the capacitor; a voltage measuring means for measuring a voltage value between both ends of the resistor; A temperature measuring means for measuring the temperature of the capacitor; Equipped with the life calculation means calculates a capacitance of the capacitor for a power supply device of the plurality of power supply devices whose switch is off based on a voltage value across the resistor and a resistance value of the resistor measured by the voltage value measurement means, and calculates a life of the capacitor based on the calculated capacitance of the capacitor and a temperature of the capacitor measured by the temperature measurement means; Each of the plurality of power supply devices includes only one capacitor that smoothes power supplied to the load. Power supply system.
3. Further comprising a current control means, Each of the plurality of power supply devices further includes a switching control circuit that controls a current output to the load, the current control means controls the switching control circuit for each of the plurality of power supply devices based on the lifetime of the capacitor calculated by the lifetime calculation means.
3. The power supply system according to claim 1 or 2.
4. The current control means further refers to schedule data relating to the operation of the power supply system, and controls the switching control circuit so that the capacitor does not reach the end of its life on a date when maintenance of the power supply system is impossible. The power supply system of claim 3.