JP4627489B2 - Uninterruptible power supply system and battery charging method - Google Patents

Description

  The present invention relates to an uninterruptible power supply system that incorporates a battery unit and supplies electric power to an electronic device uninterruptibly, and a battery charging method, and in particular, an uninterruptible power supply system that can easily add or change battery capacity and The present invention relates to a battery charging method.

  In general, an uninterruptible power supply system is connected to an electronic device such as a computer, and normally charges the battery unit while supplying electric power from a commercial power supply to the electronic device. By supplying, it is for realizing uninterruptible power.

  An uninterruptible power supply system according to the prior art includes a charging circuit connected to a commercial power supply, a battery unit that stores electric power supplied from the charging circuit, and an electric device that stores electric power stored in the battery unit when a power failure occurs A discharge circuit to be supplied to the battery and a peripheral circuit to be described later are built in one housing, and a battery unit is connected in parallel between the charging circuit and the discharging circuit.

  The battery unit uses a nickel-metal hydride battery in order to extend the life in an environment where frequent (instantaneous) blackouts occur or an environment where charging / discharging is frequently repeated by turning on / off the power source. Since the battery requires a voltage monitoring circuit / temperature monitoring circuit / control circuit (microcomputer) for controlling the monitoring circuit as compared with a lead battery or the like, the peripheral circuit becomes complicated.

In addition, the following patent document is mentioned as a literature in which the technique regarding the said uninterruptible power supply system was described.
Japanese Patent Laid-Open No. 8-33218 JP 2002-216882 A JP 2002-216882 A

  In the uninterruptible power supply system according to the above-described prior art, when charging a plurality of batteries by adding a battery unit, the battery unit is connected in parallel between the charging circuit and the discharging circuit. ) Increase the amount of current to be supplied from the charging circuit to charge a plurality of battery units at the same time, or (2) Charge the battery with a small amount of current distributed to each battery unit. Has a problem of increasing the cost of the equipment because a large-capacity power supply must be prepared, and the latter has a problem that full charge detection becomes difficult and charging efficiency is lowered.

  In addition, when an uninterruptible power supply system according to the prior art is added, the charging circuit / peripheral circuit for the additional battery part must be added, resulting in an increase in the cost of the apparatus and an increase in the case. There was a problem that extra space was required because it was necessary.

  An object of the present invention is to solve the above-described problems caused by the prior art, and an uninterruptible power supply system capable of performing charging and discharging in a balanced manner for a plurality of battery units without preparing a large capacity power supply. And a method of charging the uninterruptible power supply system.

Power invention of claim 1, wherein in order to achieve the object, a plurality of battery unit for storing electric power, which is storing power from the external power supply and charging circuit for charging the plurality of battery unit, to the battery unit An uninterruptible power supply system, comprising: a discharge circuit that outputs to the outside; and a control circuit that controls the charging circuit and the discharging circuit and switches the charging of the plurality of battery units at a specified time. However, the battery unit capacity is α [Ah], the charging current is β [A], the minimum time required for full charge detection is t ₀ [h], and the capacity ratio that allows current imbalance when discharging from the parallel battery unit is When γ [%] is set and the specified time is tx [h] and tx> t ₀ , the specified time tx [h] is obtained by Equation 1 [tx <α × γ / (100 × β)]. Features set to range And

The invention according to claim 2 is a plurality of battery units for storing electric power, a charging circuit for charging electric power from an external power source to the plurality of battery units, and a discharging circuit for outputting electric power stored in the battery unit to the outside. And a battery charging method for an uninterruptible power supply system comprising: a control circuit that controls the charging circuit and the discharging circuit and switches the charging to the plurality of battery units at specified time intervals, wherein the control circuit includes a battery the part volume α [Ah], the charging current β [a], satisfy the minimum time required for charge detection t ₀ [h], the volume ratio can tolerate a current imbalance when the discharge from the parallel battery unit γ [% When the specified time is tx [h] and tx> t ₀ , the specified time tx [h] is set to a range obtained by Formula 1 [tx <α × γ / (100 × β)]. characterized in that it .

  According to the uninterruptible power supply system according to claims 1 to 4 of the present invention, the charging to the plurality of battery units is performed by switching the charging unit at a predetermined time, thereby providing a plurality of battery units without preparing a large-capacity power source. Balanced charging and discharging can be performed.

Hereinafter, an embodiment of an uninterruptible power supply system and a charging method of the uninterruptible power supply system according to the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing a detailed configuration of an uninterruptible power supply system and a charging method for the uninterruptible power supply system according to the present embodiment, FIG. 2 is a flowchart for explaining the operation of the uninterruptible power supply unit, and FIG. The figure which shows the relationship between the charge amount at the time of the division | segmentation charge by a form, and a charging current, FIG. 4 is a figure which shows the charge start and battery switching sequence by this embodiment, FIG. 5 is an uninterruptible power supply system by other embodiment of this invention FIG.
<Description of configuration>

  As shown in FIG. 1, the basic configuration of the uninterruptible power supply system according to the present embodiment includes an input circuit 10 connected to a commercial power supply, and a basic battery unit 30 that charges and discharges power input from the input circuit 10. A discharge circuit 60 for supplying electric power of the basic battery unit 30 to a connected electronic device in the event of a power failure, a control circuit 40 connected to each circuit and controlling each circuit, and a battery group of the battery unit The additional battery unit 50 is configured to be added in parallel with the basic battery unit 30 when the battery is added. The input circuit 10 includes an inrush current prevention circuit 11 for preventing an inrush current from a power source, the charging circuit 20 includes a boost control circuit 21 and a constant current control circuit 22, and the discharge circuit 60 includes an output control circuit. 61. However, since these detailed circuit configurations are known circuits, description thereof is omitted.

  The control circuit 40 controls charging using a control command unit 42 to which power is supplied from the input circuit 10 via a PS (power supply) 41, and the boost control circuit 21 and the constant current control circuit 22 of the charging circuit 20. A charge command circuit 43, a charge switching circuit 45 that controls switching of charging, which will be described later, an output command circuit 47 that controls output from the discharge circuit 60, an interface circuit 48 connected to an external electronic device, etc., a battery A resistance measurement command circuit 46 is provided for instructing a circuit that generates a pulse current to measure the resistance values of the part 30 in the unit 30 and the part 50 in the unit 5c.

The basic battery unit 30 detects a drive circuit 3a that controls a switching element (MOS) that performs charging on / off, a battery group 3c that charges and discharges power, and a voltage and temperature of the battery group 3c. A voltage / temperature detection circuit 3b and a drive circuit 3d that operates to flow a pulse current to the battery group 3c in response to a command from the resistance measurement command circuit 46. Similarly, the additional battery unit 50 turns on / off charging. Drive circuit 5a for controlling a switching element (MOS) to be performed, battery group 5c for charging and discharging power, voltage / temperature detection circuit 5b for detecting voltage and temperature of the battery group 5c, and the resistance measurement command circuit And a drive circuit 5d that operates to cause a pulse current to flow through the battery group 5c in response to a command from 46.
<Description of operation>

  In the uninterruptible power supply system and the battery charging method according to the present embodiment, the charge switching circuit 45 of the control circuit 40 is connected to the drive circuits 3a and 5a of the battery units 30 and 50, and the basic battery unit 30 or the additional battery unit 50 is connected. Is controlled so as to be charged in a time-sharing manner. The charge switching circuit 45 has a function of performing charging in a time-sharing manner so that individual charging does not overlap in time even when an additional battery unit is connected.

  This time-division charging includes a symbol a indicating the relationship between the charging current and the charging amount of the basic battery unit 30, a symbol b indicating the relationship between the charging current and the charging amount of the additional battery unit 50, as shown in FIG. As is apparent from the reference c indicating the relationship between the charging current and the charging amount of the battery unit, by charging the basic battery unit 30 and the additional battery unit 50 for a predetermined time, It works to increase in steps.

  As shown in FIG. 2, the time division charging control is performed by measuring the voltage of the 0 system (basic battery unit 30) (step 102) and the voltage of the 1 system (additional battery unit 50) by starting charging (step 101). Measurements (step 103) are sequentially performed to determine whether or not the 0 system voltage is lower than the 1 system (step 104). If the 0 system voltage is low, charging of the 1 system is suspended and 0 is output. The system is charged (step 105), and whether or not the 0 system is fully charged is constantly monitored (steps 106 and 110) until the specified time is reached. Charging of the system is started (step 107), and operation is performed so as to complete the charging when the full charge of this system 1 is detected (step 108). When the specified time elapses before the 0 system reaches full charge in the step 106 (step 110), the 0 system charge is suspended (step 111) and the 1 system charge is started (step 111). Whether the 1 system is fully charged is constantly monitored (steps 112 and 115) until the specified time is reached. When the 1 system is fully charged, charging of the 1 system is suspended and charging of the 0 system is resumed (step 113). , It operates so as to complete the charging when the 0 system full charge is detected (step 114). When the specified time elapses before the first system reaches full charge in step 112 (step 115), the first system is stopped and the zero system charge is resumed, and the operation returns to step 106.

  Further, in the system, when it is determined that the voltage of the 1 system is low as a result of the voltage comparison between the 0 system and the 1 system in the step 104, the charging of the 0 system is determined to have elapsed in the step 110, and Similarly, in step 111, charging of system 0 is suspended and charging of system 1 is started (step 111). Whether the 1 system is fully charged is constantly monitored (steps 112 and 115) until the specified time is reached. When the 1 system is fully charged, charging of the 1 system is suspended and charging of the 0 system is resumed (step 113). , It operates so as to complete the charging when the 0 system full charge is detected (step 114). When the specified time elapses before the first system reaches full charge in step 112 (step 115), the first system is stopped and the zero system charge is resumed, and the operation returns to step 106.

  As described above, the uninterruptible power supply system and the battery charging method according to the present embodiment are configured such that when a plurality of battery units are connected, power is supplied to each battery unit in a time-sharing manner for every specified time to perform charging. There is no need to prepare a large-capacity power source for charging each individual battery, and the effect that the full charge detection is easy because the conventional detection technology for each battery unit is used.

  The specified time for switching the time division charging of the battery unit may be limited by a plurality of parameters such as the battery unit capacity of the battery unit.

Specifically, (1) the battery unit capacity, which is a parameter determined by the battery used in the battery unit, is α [Ah], and (2) the charging current, which is a parameter obtained by setting the circuit (charging circuit). β [A], (3) The specified time (switching time) is tx [h], (4) The minimum time required for full charge detection, which is a parameter determined by the characteristics of the battery unit and the charge control method, is t ₀ [h] (5) When the capacity ratio that can allow current imbalance when discharging from a parallel battery, which is a parameter that can be estimated by the characteristics of the battery unit and the circuit / use method, is γ [%], the specified time tx is expressed by the following equation: 2 and Equation 3 can be used for calculation.
From the conditions that determine the maximum value of tx

    γ> β × tx / α × 100 Formula 1

  ∴tx <α × γ / (100 × β) ·· Formula 2

    From the conditions that determine the minimum value of tx

tx> t ₀ .. Formula 3

Specifically, for example, a battery with α = 6.4 [Ah] is used, and β = 0.5 [Ah], γ = 30 [%], and t ₀ = 2 [Ah] are set. In this case, tx <3.84 [h] is obtained from Equation 2, and tx> 2.0 [h] is obtained from Equation 3, and therefore tx = 3 [h] is set, that is, the switching time is set to 3 hours.

  As shown in FIG. 4A, the sequence for starting the charging of the battery units 30 and 50 includes (1) a step in which the control circuit unit detects the voltage of the basic battery unit, and (2) the control circuit unit in the additional battery. The step of detecting the voltage of the part, (3) the step of issuing a charging command by the control circuit part, (4) the step of checking the charging operation signal by the control circuit part, and (5) the basic battery part to be charged. In some cases, the control circuit sequentially performs a process of issuing a command to turn on the MOS of the drive circuit 3a of the basic battery unit, and at this time, the additional battery unit is in a charging suspension state.

  As shown in FIG. 4 (b), the sequence for stopping charging of the battery unit 30 and starting charging of the battery unit 50 is as follows. The step of canceling the MOS on command of the drive circuit 3a in the battery unit and the step (2) of issuing the command to turn on the MOS of the drive circuit 5a of the additional battery unit are sequentially executed with sufficient intervals not to be turned on at the same time. Is done by doing.

As described above, the uninterruptible power supply system according to the present embodiment can be easily expanded without increasing the power supply facilities for the plurality of battery units by switching the charging for the plurality of battery units at predetermined time intervals. Further, the specified time for switching can be set as follows: capacity α [Ah] / charging current β [A] / minimum time required for full charge detection t ₀ [h] / capacitance ratio that allows current imbalance during discharge By determining γ [%] as a factor, a plurality of battery units can be charged and discharged in a balanced manner.
<Other embodiments>

  FIG. 5 is a diagram for explaining an uninterruptible power supply system and a battery charging method according to another embodiment of the present invention. As shown in FIG. 5, the uninterruptible power supply system according to this embodiment includes an inrush current prevention circuit 71 connected to a power supply, a charging circuit 72, and a battery group having different capacities connected to the charging circuit 72 via a switch. 76a and 76b, a discharge circuit 77a for discharging power from the battery group 76a from CH (channel) 1, and a discharge circuit 77b for outputting power from the battery group 76b from CH (channel) 2. The charging circuit 72 and the discharging circuits 77a and 77b are configured to perform charging and discharging according to the connected electronic device under the control of the control circuit.

  The charging circuit 72 according to the present embodiment depends on the capacity ratio of the battery groups 76a and 76b / charge current value / minimum time required for full charge detection / importance of backup duty for each CH (channel) and required backup capacity. Thus, it is possible to perform charging in which the charging current and the specified time for each of the battery groups 76a and 76b are determined. For example, in the case where the capacity ratio of each battery group 76a and 76b is 1: 2, and when the backup duty of CH (channel) 1 is given priority, first, charging of CH (channel) 1 is completed until full charge, Thereafter, CH (channel) 2 may be charged. In addition, when the backup duty is equally important for each CH (channel), the specified switching time can be set at a time corresponding to the capacity ratio 1: 2 over the minimum time required for full charge detection. . In addition, the discharge circuits 77a and 77b have characteristics of an electronic device connected to the channel, for example, a characteristic that requires a long-time backup although the instantaneous current is small according to the electronic device for a memory or the like. Long-term backup according to the device is not required, but the discharge is performed according to the characteristics that require instantaneous power.

  In the uninterruptible power supply system according to the present embodiment, the battery groups 76a and 76b are switched by the control circuit (not shown) to charge the battery groups 76a and 76b as in the above-described embodiment, so that both the battery groups 76a and 76a 76b can be charged, and each discharge circuit 7a and 7b can discharge electric power according to an electronic device connected from each CH (channel).

  In the above-described embodiment, an example in which the additional battery unit is one set with respect to the basic battery unit has been described. However, the present invention is not limited to this, and a plurality of additional battery units can be added as necessary. You can also

The figure which shows the structure of the uninterruptible power supply system by one Embodiment of this invention. The flowchart for demonstrating operation | movement of this uninterruptible power supply unit. The figure which shows the relationship between the charge amount and charging current by this embodiment. The figure which shows the charge start and battery switching sequence by this embodiment. The figure which shows the structure of the uninterruptible power supply system by other embodiment of this invention.

Explanation of symbols

  3a: drive circuit, 3b: temperature detection circuit, 3c: battery group, 3d: drive circuit, 5a: drive circuit, 5b: temperature detection circuit, 5c: battery group, 5d: drive circuit, 7a: discharge circuit, 10: input Circuit: 11: inrush current prevention circuit, 20: charging circuit, 21: boosting control circuit, 22: constant current control circuit, 30: basic battery unit, 40: control circuit, 42: control command unit, 43: charge command circuit, 45: charge switching circuit, 46: resistance measurement command circuit, 47: output command circuit, 48: interface circuit, 50: additional battery unit, 60: discharge circuit, 61: output control circuit, 70: current detection circuit, 71: inrush Current prevention circuit, 72: charging circuit, 76a: battery group, 76b: battery group, 77a: discharging circuit, 77b: discharging circuit.

Claims (2)

A plurality of the battery unit, and a charging circuit for charging the power from an external power source to the plurality of battery unit, a discharge circuit for outputting electric power accumulated in the battery unit to the outside, the charging circuit and the discharging circuit for storing power And an uninterruptible power supply system comprising a control circuit that switches the charging of the plurality of battery units at specified time intervals, wherein the control circuit has a battery unit capacity α [Ah] and a charging current β [A], the minimum time required for full charge detection is t ₀ [h], the capacity ratio that can allow current imbalance when discharging from the parallel battery unit is γ [%], and the specified time is tx [h], when the tx> _{t 0,} uninterruptible power supply system and sets the prescribed time tx [h], the range obtained by equation 1 [tx <α × γ / (100 × β)]. A plurality of battery units for storing electric power, a charging circuit for charging electric power from an external power source to the plurality of battery units, a discharging circuit for outputting electric power stored in the battery unit to the outside, the charging circuit and the discharging circuit And a battery charging method for an uninterruptible power supply system comprising a control circuit that switches the charging of the plurality of battery units at specified time intervals, wherein the control circuit has a capacity of the battery unit α [Ah], The charging current is β [A], the minimum time required for full charge detection is t ₀ [h], the capacity ratio that can allow current imbalance when discharging from the parallel battery unit is γ [%], and the specified time is tx [h], when the tx> _{t 0,} the tx [h] the prescribed time, equation 1 [tx <α × γ / (100 × β)] of the battery and setting the range obtained by Charging method.

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