JP2016018263A - Divided voltage power supply system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a DC power supply system having small power loss, and capable of improving power supply efficiency.SOLUTION: A DC power supply system 1 includes a plurality of load units 11a to 11n that are connected in series to a power supply system 10 and are configured so that a DC voltage from the power supply system 10 is divided and supplied. The plurality of load units 11a to 11n respectively comprise: primary capacitors C1 charged from the power supply system 10; voltage control devices 12a to 12n that are connected to the respective primary capacitors C1 and adjust respective supply voltages to respective output sides according to load variation; secondary capacitors C2 for charging the respective adjusted supply voltages; and loads 13a to 13n to which power is supplied through the respective secondary capacitors C2.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a DC power supply system that supplies power to a load device.

  In order to supply power to a load device such as an ICT (Information and Communication Technology) device, a server, or a router, a conventional DC power supply system converts a supply voltage from a power supply system into a predetermined voltage and supplies power to the load device ( Patent Document 1).

FIG. 1 is a diagram showing a configuration of a conventional DC power supply system 100. In FIG. 1, the DC power supply system 100 includes a power supply system 101 and a plurality of load devices 102 a to 102 n that receive a supply voltage of 48 V from the power supply system 101.
Each of the load devices 102a to 102n includes voltage conversion devices 103a to 103n and loads 104a to 104, respectively. Each voltage converter 103a-103n is comprised so that the voltage of 48V may be converted into 12V.

JP 2006-304450 A

  A conventional DC power supply system includes a voltage conversion device that converts a supply voltage to a load. However, since the voltage conversion device incorporates a transformer, a switching element, and the like for voltage conversion, in this voltage conversion device, power loss such as iron loss and copper loss increases, and power supply efficiency decreases. Therefore, a DC power supply system with low power loss and high power supply efficiency is desired.

  The present invention has been made under such circumstances, and an object of the present invention is to provide a direct current power supply system that can reduce power loss and improve power supply efficiency.

  An invention for solving the above-mentioned problem includes a plurality of load devices connected in series with a power supply and configured to supply power by dividing a DC voltage from the power supply, Each is connected to the primary capacitor charged from the power supply, the voltage controller connected to the primary capacitor and adjusting the supply voltage to the output side according to load fluctuations, and the output side of the voltage controller. A secondary capacitor that charges the adjusted supply voltage; and a load that receives power supply via the secondary capacitor.

  The above invention may further include a monitoring device that monitors a load variation of each of the load devices and outputs a control signal for adjusting the supply voltage to the voltage control device based on the result.

  The above invention may further include an electronic load device connected in series with the plurality of load devices.

  According to the present invention, power loss is small and power supply efficiency is improved. In addition, according to the present invention, since power loss is small and power supply efficiency is improved, power consumption of the load device is reduced.

It is a figure which shows the structure of the conventional DC power supply system. It is a mimetic diagram showing the example of composition of the direct-current power supply system of a 1st embodiment. It is a figure which shows the example of the conversion efficiency of a voltage. It is a figure which shows the measurement result about the input voltage of a load apparatus in the case of supplying electric power to four load apparatuses, and the power consumption of load. It is a schematic diagram which shows the structural example of the DC power supply system of 2nd Embodiment. It is a schematic diagram which shows the structural example of the DC power supply system of 3rd Embodiment. It is a schematic diagram which shows the structural example of the DC power supply system of 4th Embodiment. It is a schematic diagram which shows the structural example of the DC power supply system of 5th Embodiment. It is a schematic diagram which shows the structural example of the DC power supply system of 6th Embodiment.

<First Embodiment>
Hereinafter, a DC power supply system 1 according to a first embodiment of the present invention will be described with reference to FIGS. 1 and 2. FIG. 2 is a schematic diagram illustrating a configuration example of the DC power supply system 1 of the present embodiment. FIG. 3 is a diagram for explaining an example of conversion efficiency of converters having different input / output characteristics.

  As shown in FIG. 2, a DC power supply system 1 is connected in series via a power supply system (power supply) 10 and the power supply system 10 and a power supply line 21, and a DC voltage from the power supply system 10 is divided and supplied. A plurality of load devices 11a to 11n configured to be configured as described above.

  The load devices 11a to 11n are, for example, ICT devices, servers, routers, and the like. The number of load devices is not limited to the number shown in FIG. 2 and can be changed.

  Each of the load devices 11a to 11n includes a primary capacitor C1 charged from the power supply system 10 and voltage control devices 12a to 12n that are connected to the primary capacitor C1 and adjust the supply voltage to the output side according to the load fluctuation. Have. Further, each of the load devices 11a to 11n is connected to the output side of the voltage control devices 12a to 12n, and receives power supply through the secondary capacitor C2 that charges the adjusted supply voltage and the secondary capacitor C2. Load 13a-13n.

  The loads 13a to 13n are, for example, a POL (Point of Load), a circuit including a CPU (such as a motherboard), a power sensor, or the like.

The monitoring device 20 is connected to the load devices 11a to 11n via the communication line 22, and monitors the load fluctuations of the load devices 11a to 11n. The communication line 22 is, for example, an optical cable.
The monitoring device 20 outputs a control signal for adjusting the supply voltage to the voltage control devices 12a to 12n based on the monitoring result.
Although FIG. 2 shows the case where all the load devices are monitored by one monitoring device 20, the load devices can be monitored by two or more monitoring devices.

  In FIG. 2, the power supply system 10 includes a rectifier, a PDF (Power Distribution Flame), and a storage battery, and is configured to supply a voltage Vall. In the present embodiment, each of the voltage control devices 12a to 12n is connected in parallel with the primary capacitor C1, whereby the input side of each of the voltage control devices 12a to 12n is input voltage Vc1 to Vcn obtained by dividing the voltage Vall. Is supplied.

Note that the power consumptions P _{L1 to} P _Ln of the loads 13a to 13n shown in FIG. 2 are monitored by the monitoring device 20, and the monitoring device 20 loads the loads 11a to 11n based on the fluctuations in the power consumption (load fluctuations). A control signal for adjusting the supply voltage is output to the voltage control devices 12a to 12n. With this control signal, the voltage control devices 12a to 12n can adjust the magnitude of the supply voltage to the loads 13a to 13n.

  In general, the conversion efficiency of current converters is about 90% to 96% even if it is high, so a conversion loss of about 4% to 10% occurs. This conversion loss is caused by the voltage difference before and after the conversion. The smaller, the smaller. In other words, the smaller the voltage difference before and after conversion, the greater the conversion efficiency.

  FIG. 3 shows the conversion efficiency of a 12V input-12V output converter and the conversion efficiency of a 48V input-12V output converter. In FIG. 3, the conversion efficiency of the converter increases when 12V input and 12V output.

  From this point of view, in the voltage converters 12a to 12n of the present embodiment, the voltage is converted so that the difference between the input voltage and the output voltage is reduced so that the conversion efficiency is increased.

  In the DC power supply system 1, the power supply voltage Vall is divided between the load devices 11a to 11n connected in series. Thereby, the voltage converter provided in the conventional DC power supply system becomes unnecessary. Accordingly, power loss is reduced, and power can be supplied to the load devices 11a to 11n with high efficiency.

P _{L1 to} P _Ln shown in FIG. 2 indicate the respective powers of the loads 13a to 13n. When the values of P _{L1 to} P _Ln vary, the monitoring device 20 derives each value in the following formulas (1) to (4). The value of the power supply voltage Vall of the power supply system 10 is represented by the following formula (1).

  In the formula (1), x is 1 to n.

  The total load power Pall of the loads 13a to 13n is expressed by the following formula (2).

  In the formula (2), x is 1 to n.

  The total load current Iall of the loads 13a to 13n is expressed by the following formula (3).

Each voltage _{V Lx} load 13a~13n is represented by the following formula (4) (X = 1~n) .

When the value of V _Lx shown in Expression (4) is derived, the monitoring device 20 outputs a control signal for adjusting the voltage supplied to the load to the value of V _Lx to each of the voltage control devices 12a to 12n. To do. Each voltage controller 12a.about.12n, based on the control signal, the voltage supplied to the load 13 a to 13 _n, is adjusted to a value of _{V Lx.} As a result, the adjusted voltage is supplied to the loads 11a to 11n via the secondary capacitor C2. The secondary capacitor C2 can cope with a sudden change in the load of the load devices 11a to 11n.

  In FIG. 2, for example, when there are four load devices, the DC power supply system 1 has a configuration as shown in FIG.

Next, the DC power supply system 1 at the time of load fluctuation will be described with reference to FIG.
FIG. 4 is a diagram for explaining the situation of the DC power feeding system 1 that feeds power to the four load devices 11a to 11d.
In the DC power supply system 1, the supply voltage Vall of the power supply system 10 is DC48V. The load devices 11a to 11d are all ITC devices, and the input voltages of the load devices 11a to 11d, that is, the values of Vc1 to Vc4 are set to be DC 12V.

  In FIG. 4, the power supply voltage Vall (= 48V) from the power supply system 10 is divided between the four load devices 11a to 11d, and as a result, each load device has DC 12V as the voltages Vc1 to Vc4. Power is supplied. At this time, the monitoring device 20 acquires the power consumption of the loads 13a to 13d and outputs a control signal corresponding to the load fluctuation to the voltage control devices 12a to 12d.

  The operation of the DC power supply system 1 has stages at start-up, operation, and termination. These stages will be described below.

(At startup)
First, in the initial state, the voltage control devices 12a to 12d are all in the off state. When the power supply system 10 is turned on, the primary capacitor C1 in each of the load devices 11a to 11d is charged by the current from the power supply system 10, and the voltage of the primary capacitor C1 becomes constant. Then, the monitoring device 20 turns on the voltage control devices 12a to 12d all at once. The secondary capacitor C2 is charged by the current from the voltage control devices 12a to 12d, and the voltage of the secondary capacitor C2 becomes constant.

(In operation)
During operation, for example, when the power consumption of a certain load device 11a increases, the monitoring device 20 reduces the load voltages Vc2 to Vc4 of the load devices 11b to 11d other than the load device, thereby increasing the power consumption. A large amount of power is supplied to the load 13a of the device 11a. In this case, the monitoring device 20 instructs the voltage conversion devices 12a to 12d using the control signal.

  In FIG. 4, the monitoring device 20 constantly monitors the power consumption of the load devices 11a to 11d, and detects, for example, an increase in power consumption of the load 13a from the result. And the monitoring apparatus 20 controls the voltage control apparatuses 12a-12d so that big electric power is supplied with the secondary capacitor | condenser C2 of the load apparatus 11a for the load 13a which requires larger electric power. In this case, the monitoring device 20 calculates the control voltage of each of the load devices 11a to 11d (see the above formulas (1) to (4)), and sends a control signal that is a command value to each voltage control device 12a.

Each of the voltage control devices 12a to 12d controls the magnitudes of the input voltages V _{c1 to} V _c4 of the primary capacitor C1 according to the control signal from the monitoring device 20. As a result, for example, since the input voltage Vc1 of the primary capacitor C1 of the load device 11a increases, the voltage supplied to the load 13a increases and the voltage is supplied to the load 13a.

(When finished)
The monitoring device 20 turns off the voltage control devices 12a to 12d all at once. Thus, the value of Vc1-Vc4 when the monitoring apparatus 20 controls is shown below.

In the initial state, the values of V _{c1 to} V _c4 are 12V, and the values of P _{L1 to} P _L4 are 120W. In operation, for example, when only the value of P _L1 changes to 130 W, the total load power Pall is 490 W from the above equation (2). At this time, the total load current Iall is 10.2 A from the above equation (3). Therefore, from the above equation (4), the value of V _c1 is 12.7 V, and the values of V _{c2 to} V _c4 are all 11.8 V.

In the embodiment shown in FIG. 4, the voltage Vall is divided into the load devices 11a to 11d, and the monitoring device 20 has the magnitudes of the input voltages V _{c1 to} V _c4 according to the load fluctuations of the load devices 11a to 11d. To control. As a result, power loss is small and power supply efficiency is improved. Moreover, according to this embodiment, since power loss is small and power supply efficiency is improved, the power consumption of the load devices 11a to 11d is reduced.

Second Embodiment
Next, a DC power supply system 1A that is a second embodiment will be described. The DC power supply system 1A supplies power to the load device by high-voltage DC transmission (HVDC). In the following description, the symbols used in the description of the first embodiment are used as they are unless otherwise specified.

FIG. 5 is a schematic diagram illustrating a configuration example of the DC power supply system 1A of the present embodiment.
In FIG. 5, in the DC power supply system 1 </ b> A, the HVDC power supply system 10 </ b> A supplies power by dividing the DC voltage of the power supply system 10 </ b> A via the power supply line 21 for the eight load devices 11 a to 11 h. The power supply voltage of the power supply system 10A is, for example, DC 380V, and the supply voltage to each load device is, for example, DC 48V.

Since the DC power supply system 1A of the present embodiment performs floating grounding for safety, there are two current paths. That is, the monitoring device 20A monitors the power consumption through the communication line 22 for the four load devices 11a to 11d, and further the voltage control devices 12a to 12d of the load devices 11a to 11d according to the result. A control signal is output. Thereby, the magnitudes of the input voltages V _{c1 to} V _c4 are controlled.

  The monitoring device 20B monitors the power consumption through the communication line 22 for the four load devices 11e to 11h, and further controls the voltage control devices 12e to 12h of the load devices 11e to 11h according to the result. Output a control signal. Thereby, the magnitudes of the input voltages Vc5 to Vc8 are adjusted.

Note that the control processing of the input voltages V _{c1 to} V _c8 in FIG. 5 is the same as that shown in FIGS. 3 and 4 in this embodiment.

In the initial state, the values of V _{c1 to} V _c8 are 48V (that is, Vall = 384V), and the values of P _{L1 to} P _L8 are 480W. And, for example, when P _L1 = 500 W and P _L5 = 450 W are changed during operation, V _c1 = 49.5 V, V _{c2 to} V _c4 = 46.1 V from the above formulas (2) to (4), V _c5 = 45.7 V and V _{c6 to} V _c8 = 48.8 V.

  Even in this case, the voltage Vall is divided into the load devices 11a to 11h, and the monitoring devices 20A and 20B have the magnitudes of the input voltages Vc1 to Vc8 according to the load fluctuations of the target load devices 11a to 11h. To control. As a result, power loss is small and power supply efficiency is improved. Moreover, according to this embodiment, since power loss is small and power supply efficiency is improved, the power consumption of the load devices 11a to 11h is reduced.

<Third Embodiment>
The magnitude of power consumption in each load can be controlled to be equal. For example, FIG. 6 illustrates a configuration aspect of the DC power supply system 1B that the monitoring device 20 controls so that the power consumption of the loads 13a to 13d becomes equal.

The power consumptions P _{L1 to} P _L4 of the loads 13a to 13d are measured by the monitoring device 20, and the loads 13a to 13d are controlled so that the values of P _{L1 to} P _L4 are equal to each other. P _{L1 to} P _L4 can be adjusted. The configuration of the other DC power supply system 1B is the same as that shown in FIG.
For example, in the example shown in FIG. 4, since the values of P _{L1 to} P _L4 during operation are 122.5 W, they are constant at V _{c1 to} V _c4 = 12V.

Next, the monitoring device 20 controls the voltage control devices 12a to 12d for the load devices 11a to 11d according to the power consumptions P _{L1 to} P _{L4 that} are evenly adjusted via the communication line 22. Is output. As a result, variations in load fluctuations are reduced, and the capacitances of the primary capacitor C1 and the secondary capacitor C2 can be reduced accordingly.

<Fourth embodiment>
In each of the above-described embodiments, the case where the input voltages of the load devices are the same has been described, but there may be cases where the input voltages are different. Therefore, it is preferable that power can be supplied to load devices having different input voltages instead of the same input voltage.

FIG. 7 is a schematic diagram similar to FIG. 3. As an example of a DC power supply system 1 </ b> C including load devices 12 a to 12 g having different input voltages, input voltages V _{c1 to} V _c4 of the load devices 11 a to 11 d are 12 V, input voltage _V c5 _{~V c7} of the load device 11e~11g is shown a case where the 48V.

In the initial state, V _{c1 to} V _c4 = 12 V, V _{c5 to} V _c7 = 48 V (that is, Vall = 380 V), P _{L1 to} P _L4 = 120 W, and P _{L5 to} P _L7 = 480 W. And, for example, when the operation changes to P _L1 = 132W and P _L5 = 432W, from the above formulas (2) to (4), V _c1 = 13.5V, V _{c2 to} V _c4 = 12.2V, V _c5 = _44.0V, the _V c6 ~V c7 = 48.9V.

The monitoring device 20 controls the input voltages V _{c1 to} V _c4 with priority over the input voltages V _{c5 to} V _c7 . This is because the power fluctuation range of the powers P _{L1 to} P _L4 is larger than the power fluctuation range of the P _{L5 to} P _L7 , so that the load devices 11 a to 11 d are more affected by the current change than the load devices 11 e to 11 g. This is because it becomes easier. As a result, the voltage Vall is also divided into the load devices 11a to 11g in which different input voltages are mixed, and the monitoring device 20 increases the input voltages Vc1 to Vc7 according to the load fluctuations of the target load devices 11a to 11g. To control. As a result, power loss is small and power supply efficiency is improved. Moreover, according to this embodiment, since power loss is small and power supply efficiency is improved, the power consumption of the load devices 11a to 11g is reduced. Furthermore, it is possible to stably supply power to a load device that operates at low power, or it is possible to reduce the capacity of the primary capacitor C.

<Fifth Embodiment>
In each of the above-described embodiments, the case where power is supplied to a plurality of load devices has been described. However, it may be impossible to prepare a predetermined number of load devices necessary for partial pressure. Therefore, it is preferable to provide an electronic load device.

  FIG. 8 is a schematic diagram similar to FIG. 4, and shows a case where three load devices 11 a to 11 c and one electronic load device 50 are provided as an example of a DC power supply system 1 </ b> D including an electronic load device. It is shown.

In the DC power supply system 1D, the monitoring device 20, in addition to the input voltage _V c1 _{~V c3} of the voltage control device 12 a to 12 c, further measures the voltage _{V 50} of the electronic load device 50.
The monitoring device 20, and a load power _P L1 _{to P L3} and the total load current Iall, in addition to the load voltage _V c1 _{~V c3,} further derives a voltage V50 of the electronic load 50.
Moreover, the monitoring device 20 includes a respective load voltage Vc1~Vc3 for the voltage controller 11 a to 11 c, by specifying a voltage _{V 50} of the electronic load 50, the voltages of the load device 11 a to 11 c and an electronic load device 50 Control.

Thus, the DC power supply system 1D of the present embodiment, even when the number of the load device is insufficient to suppress the current variation in the load device 11a~11c by the monitoring device 20 changes the voltage V ₅₀ of the electronic load device 50 It becomes possible. Further, the amount of current flowing through the electronic load device 50 can be controlled by the control of the monitoring device 20, and voltage fluctuations of the load devices 11a to 11c can be suppressed.

8, for example, if not controlled voltage _{V 50} of the electronic load 50, that is, if the value of _{V 50} is constant, the voltage fluctuation of the load device 11a~11c decreases. For example, in the initial state, when V _{c1 to} V _c3 = 12 V and V ₅₀ = 11.8 V (constant value), P _{L1 to} P _L3, P ₅₀ = 120 W. And, for example, when P _L1 changes to 130 W during operation, V _c1 = 12.7 V and Vc _{2 to} V _c3 = 11.8 V from the above formulas (2) to (4).

<Sixth Embodiment>
In each of the above-described embodiments, no mention was made of power supplied directly from the storage battery in the power supply system to the load device. However, when the storage battery and the load device are directly connected, the supply voltage to the load device does not decrease. It is preferable to do so.

  FIG. 9 is a schematic diagram similar to FIG. 8, and includes load devices 11 a to 11 d, a monitoring device 20, and an electronic load device 50 as an example of a DC power supply system 1 E that receives power supply from the storage battery 60. Furthermore, the case where the switch 61 is provided between the storage battery 60 and each apparatus 11a-11d, 20,50 is shown.

In the DC power supply system 1E, the monitoring device 20 measures the respective input voltages of the voltage control device 12 a to 12 d VC1 to VC4, the voltage _{V 50} of the electronic load device 50. Then, the monitoring device 20 calculates the total load voltage Vall (= V _c1 + V _c2 + V _c3 + V _c4 + V ₅₀ ), and switches the switch 61 when the value of Vall is less than a predetermined value (for example, 43.2 V). The load devices 11a to 11d and the electronic load device 50 are connected in series. The monitoring device 20, similarly to the case shown in FIG. 8, suppress the current variation in the load device 11a~11c by changing the voltage _{V 50} of the electronic load device 50.

  On the other hand, when the value of Vall described above is larger than a specified value (for example, 52.8 V), the monitoring device 20 switches the switch 61 and disconnects the load devices 11a to 11d from the electronic load device 50. That is, the load device 11a is connected to the storage battery 60 via the switch 61.

  Even if comprised in this way, in addition to having the effect of the fifth embodiment described above, it is possible to cope with a large increase and decrease in the supply voltage of the DC power supply system 1E. The load can be stably operated.

  In addition, each said embodiment is not restricted to the example mentioned above, It can change. For example, the number of load devices, the input voltage (may be a plurality of different values), and the like can be changed.

1, 1A, 1B, 1C, 1D, 1E DC power supply system 10 Power supply system 11a to 11n Load device 12a to 12n Voltage control device 20 Monitoring device 21 Power supply line 22 Communication line 60 Storage battery 61 Switch C1, C2 Capacitor

Claims (4)

A plurality of load devices that are connected in series with a power supply and configured to be divided and fed with a DC voltage from the power supply;
Each of the plurality of load devices is
A primary capacitor charged from the power supply;
A voltage control device that is connected to the primary capacitor and adjusts a supply voltage to the output side according to a load variation;
A secondary capacitor connected to the output side of the voltage controller and charging the regulated supply voltage;
A load receiving power supply via the secondary capacitor;
A direct current power supply system comprising:   The monitoring device according to claim 1, further comprising a monitoring device that monitors a load fluctuation of each of the load devices and outputs a control signal for adjusting the supply voltage to the voltage control device based on the result. DC power supply system.   The DC power supply system according to claim 1, further comprising an electronic load device connected in series with the plurality of load devices.   The DC power supply system according to any one of claims 1 to 3, wherein the power supply is a power supply system or a storage battery.

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