Saturable reactor device for storage battery, storage battery device, uninterruptible power supply device, and storage battery control method

Abstract

To provide a saturable reactor device for a storage battery in which zero-crossing of a floating charging current is suppressed and life of a storage battery is extended, a storage battery device, an uninterruptible power supply device, and a control method for a storage battery.SOLUTION: A saturable reactor device 12 for a storage battery includes: a first reactor 24 and a second reactor 26 that are a reactor being saturated relative to a current exceeding a predetermined value; terminals T2, T3 on a rectifier side that are connected to either of the first reactor 24 and the second reactor 26 and connected to a rectifier 10; and terminals T4 to T6 on a storage battery side connected to any of the first reactor 24 and the second reactor 26 and connected to a storage battery 14. A storage battery device 1 includes the saturable reactor device 12 and the storage battery 14. An uninterruptible power supply device includes the storage battery device 1.SELECTED DRAWING: Figure 5

Description

[Technical field]

[0001] The present invention relates to a saturable reactor device for a storage battery, a storage battery device, an uninterruptible power supply device, and a method for controlling a storage battery. [Background technology]

[0002] 2. Description of the Related Art Known inverter devices include the one described in Japanese Patent Laid-Open Publication No. 1-274627 (Patent Document 1). This device is equipped with a storage battery connected in parallel to the DC voltage output side of a rectifier (converter), and a reactor connected in series to the storage battery. The reactor suppresses the ripple component contained in the charging current when the storage battery is charged by the DC output of the rectifier, and saturates at a discharge current above a predetermined value when the storage battery is discharged. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 1-274627 Summary of the Invention [Problem to be solved by the invention]

[0004] In the above device, the ripple component contained in the charging current is suppressed, but the zero crossing (alternating current) of the floating charging current is not suppressed. Fig. 10 is an explanatory diagram of a conventional battery charging circuit. A rectifier CN is connected to an AC power source AE, and a battery SB is connected to the rectifier CN via a smoothing reactor FR and a smoothing capacitor FC. The battery SB is float-charged by this charging circuit. When the AC power source AE is positive, current flows in the direction of the solid arrow, and a half-wave positive voltage is generated on the battery SB side. On the other hand, when the AC power source AE is negative, current flows in the direction of the dashed arrow, and the next half-wave positive voltage is generated on the battery SB side. As shown in FIG. 11(A), the half-wave positive voltage (solid line SL) is smoothed by the smoothing reactor FR and smoothing capacitor FC (thick line TH) and is brought closer to a continuous DC voltage, but some of the waveform shape remains with bumps (part BP of thick line TH). This voltage is applied to battery SB as the difference from the original charging voltage (solid line SM on the horizontal axis in Fig. 11(B)). Then, as shown in Fig. 11(C), the current on the battery SB side takes on a waveform close to the zero point (thick line TI), and an AC superposition appears based on the bulge waveform at the positive voltage of the half wave, and positive and negative alternations, i.e., zero crossings, occur in the floating charging current on the battery SB side (points ZC1 to ZC5). And, through research by the inventors of the present application, it has now been found that the zero crossing of the floating charging current causes a shortening of the life of the storage battery SB.

[0005] Therefore, the main object of the present invention is to provide a saturable reactor device for a storage battery, a storage battery device, an uninterruptible power supply device, and a control method for a storage battery, which suppresses the zero crossing of the floating charging current and extends the life of the storage battery. [Means for solving the problem]

[0006] The invention described in claim 1 is a saturable reactor device for a storage battery, Set to a value equal to or greater than the DC current during floating charging of the battery The power supply includes a saturable reactor which is a reactor that saturates for a current exceeding a predetermined value, a rectifier side terminal connected to the saturable reactor and connected to a rectifier, and a storage battery side terminal connected to the saturable reactor and connected to a storage battery. The size of the reactor is set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charge to be smaller than the DC voltage during the floating charge. The present invention is characterized in that The invention described in claim 2 is characterized in that, in the above invention, the predetermined value is set to 1A or more. The invention described in claim 3 is characterized in that, in the above invention, the reactor before saturation in the saturable reactor is set to 1 mH or more. be.

[0007] Claim 4The invention described in the above is a storage battery device comprising the above-mentioned storage battery saturable reactor device and the storage battery. Claim 5 The invention described in the above is characterized in that an uninterruptible power supply device is equipped with the above storage battery device.

[0008] Claim 6 The invention described in the above is characterized in that, in a control method for a storage battery, a saturable reactor, which is a reactor that saturates for a current exceeding a predetermined value that is set to be equal to or greater than the DC current during floating charging of the storage battery, is connected in series between a rectifier and the storage battery, with the size of the reactor set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charging to be smaller than the DC voltage during floating charging. Claim 7 The invention described in the above is characterized in that, in the above invention, the saturable reactor is connected to the rectifier and the storage battery via terminals, respectively. Effect of the Invention

[0009] The main advantage of the present invention is that it provides a saturable reactor device for a storage battery, a storage battery device, an uninterruptible power supply device, and a control method for a storage battery, which suppress the zero crossing of the floating charging current and extend the life of the storage battery. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram of a storage battery device according to the present invention. [Diagram 2] FIG. 2 is a front view of the saturable reactor device in FIG. [Diagram 3] FIG. 2 is a top view of the saturable reactor device in FIG. [Figure 4] FIG. 2 is a side view of the saturable reactor device in FIG. [Diagram 5] 2 is a circuit diagram of the saturable reactor device, a rectifier, a storage battery, and a DC load in FIG. 1. [Figure 6]6 is a graph showing inductances associated with a first reactor and a second reactor in FIG. 5. [Figure 7] 4 is a flowchart relating to control of a storage battery by a saturable reactor device. [Figure 8] FIG. 11 is a diagram relating to a simulation of the circuit of the storage battery device before the saturable reactor device is connected. [Figure 9] FIG. 13 is a diagram relating to a simulation of the circuit of the storage battery device after the saturable reactor device is connected. [Figure 10] FIG. 1 is an explanatory diagram of a conventional charging circuit for a storage battery. [Figure 11] 11 is an explanatory diagram showing the time changes of (A) the AC side voltage, (B) the original floating charge voltage, and (C) the DC side current in FIG. 10. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, an embodiment of the present invention will be described together with modified examples with reference to the accompanying drawings. It should be noted that the embodiment is not limited to the following examples and modified examples.

[0012] ≪Configuration, etc.≫ FIG. 1 is a block diagram of a storage battery equipment 1 according to the present invention. The storage battery equipment 1 is included in an uninterruptible power supply. The storage battery equipment 1 is installed in a substation. Note that the storage battery equipment 1 does not have to be included in an uninterruptible power supply, and may be installed in a place other than a substation.

[0013] The storage battery device 1 includes an input terminal 2, an output terminal 4, a node 6, a rectifier 10, a saturable reactor device 12 for a storage battery, and a storage battery 14.

[0014] A 200V (volt) AC power source (alternating current power source) is connected to the input terminal 2. The AC power source originates from a 6.6kV (kilovolt) line of a substation. Note that the AC power source does not have to be 200V, and does not have to originate from a 6.6kV line. A DC load D (direct current load) is connected to the output terminal 4. The DC load D is a control panel, a communication device, a distribution panel, etc. However, the DC load D is not limited to these. Also, the DC load D may be a standalone device. The input terminal 2 is connected to the output terminal 4. The node 6 is interposed between the input terminal 2 and the output terminal 4.

[0015] The rectifier 10 is disposed between the input terminal 2 and the node 6. The rectifier 10 converts the AC current input to the input terminal 2 into a DC current. The saturable reactor device 12 is connected to the node 6. The saturable reactor device 12 is a device including a reactor that becomes saturated for a current exceeding a predetermined value. The storage battery 14 is a rechargeable battery. The storage battery 14 is connected to the saturable reactor device 12. The storage battery 14 is a plurality of lead-acid batteries. Note that the storage battery 14 may be a single battery or may be a battery other than a lead-acid battery. The saturable reactor device 12 is added later. That is, in a storage battery device in which the storage battery 14 is directly connected to the node 6 without the saturable reactor device 12, the saturable reactor device 12 is installed between the node 6 and the storage battery 14 to form the storage battery device 1.

[0016] Fig. 2 is a front view of the saturable reactor device 12. Fig. 3 is a top view of the saturable reactor device 12. Fig. 4 is a side view of the saturable reactor device 12. Fig. 5 is a circuit diagram of the saturable reactor device 12, the rectifier 10, the storage battery 14, and the DC load D. The saturable reactor device 12 includes a housing 20, a terminal block 22, a first reactor 24 serving as a saturable reactor, and a second reactor 26 serving as a saturable reactor. Incidentally, one saturable reactor may be provided, or three or more saturable reactors may be provided.

[0017] The housing 20 is made of metal. The terminal block 22 has six terminals T1 to T6. The terminal block 22 is attached to the upper front surface of the housing 20. The terminal T1 is connected to the housing 20 by a lead wire Z and is grounded.

[0018] FIG. 6 is a graph showing the inductances associated with the first reactor 24 and the second reactor 26. As shown in FIG.

[0019] The first reactor 24 is a variable inductance and a saturable reactor. The first reactor 24 is a coil wound around a slitted iron core. The inductance of the first reactor 24 can be switched between 1.0 mH (millihenry) and 2.0 mH. When the inductance of the first reactor 24 is 1.0 mH, the first reactor 24 saturates at a rated current of 4 A (ampere), and the inductance of the first reactor 24 becomes almost 0 for a current exceeding 4 A. When the inductance of the first reactor 24 is 2.0 mH, the first reactor 24 saturates at a rated current of 2 A, and the inductance of the first reactor 24 becomes almost 0 for a current exceeding 2 A. The first reactor 24 may be changeable to three or more types of inductance, and may not be a variable inductance. The first reactor 24 may be something other than a coil wound around a slitted iron core. The first reactor 24 has three leads E1 to E3, with the lead E1 being connected to a terminal T2 of the terminal block 22, the lead E2 being connected to a terminal T4, and the lead E3 being connected to a terminal T5. The terminal T2 is a rectifier-side terminal. The terminals T4 and T5 are storage battery-side terminals.

[0020] The second reactor 26 is a saturable reactor. The second reactor 26 is a coil wound around a slitted iron core. The inductance of the second reactor 26 is 4.0 mH at a current of 4 A or less. The second reactor 26 saturates at a current exceeding 4 A, and the inductance of the second reactor 26 becomes approximately 0. The second reactor 26 may have a variable inductance. Also, the second reactor 26 may be something other than a coil wound around a slitted iron core. The second reactor 26 has two leads F1 and F2, the lead F1 being connected to a terminal T3 of the terminal block 22, and the lead F2 being connected to a terminal T6. The terminal T3 is a rectifier-side terminal. The terminal T6 is a storage battery-side terminal.

[0021] <Control, etc.> FIG. 7 is a flowchart relating to the control of the storage battery 14 by the saturable reactor device 12. As described above, the saturation start current value of each of the first reactor 24 and the second reactor 26 in the saturable reactor device 12 is 2 A or 4 A, which is set to be equal to or higher than the DC current value (1 A) during float charging (step S1).

[0022] Moreover, when the saturable reactor device 12 is connected in series in the circuit of the storage battery equipment 1, the size of the reactor before saturation is set by selecting the terminals T2 to T6 (step S2). That is, in order to obtain an inductance of 1.0 mH in the saturable reactor device 12, the wiring from the rectifier 10 is connected to the terminal T2 of the terminal block 22, and the wiring to the storage battery 14 is connected to the terminal T4. In addition, in order to obtain an inductance of 2.0 mH in the saturable reactor device 12, a wire from the rectifier 10 is connected to the terminal T2 of the terminal block 22, and a wire to the storage battery 14 is connected to the terminal T5. Furthermore, in order to obtain an inductance of 4.0 mH in the saturable reactor device 12, a wire from the rectifier 10 is connected to the terminal T3 of the terminal block 22, and a wire to the storage battery 14 is connected to the terminal T6. The size of the reactor before saturation is set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charge of the storage battery 14 to be smaller than the DC voltage during floating charge.

[0023] Then, the saturable reactor device 12 is connected in series between the rectifier 10 and the storage battery 14 at the selected terminals T2 to T6 (step S3).

[0024] FIG. 8 is a diagram relating to a simulation of the circuit of the storage battery equipment 1 before the saturable reactor device 12 is connected. In this simulation, the wiring between the rectifier 10 and the storage battery 14 is 5 m (meters) one way (10 m round trip). Such a length of wiring is an average length in a substation. The inductance L2 of this wiring is 1 [μH / m (microhenries per meter)] × 10 [m] = 10 [μH], and the resistance R4 of this wiring is 183 [mΩ / km (milliohms per kilometer)] × 0.01 [km] = 1.83 [mΩ]. The DC output voltage V1 of the rectifier 10 for floating charging the storage battery 14 is set to 2.15 [V / cell] x 52 [cells] = 111.8 [V], and the floating charging current is set to 1 [A]. That is, the storage battery 14 is set to be a lead-acid battery having 52 cells, and a typical current value for floating charging is set. Such a number of cells for the storage battery 14 is commonly seen in substations. In addition, the internal resistance R1 of the storage battery 14 is set to 0.45 [mΩ / cell] × 52 [cells] = 23.4 [mΩ] based on the actual situation. In addition, the storage battery 14 is set as a capacitor C1 in the simulation, and its capacitance is set to 1 [F (Farad)].

[0025] Furthermore, the ripple voltage e1 superimposed on this DC output voltage V1 is set to 1 V (peak-to-peak value) in the rectifier 10, and the frequency of the ripple voltage e1 is set to 360 Hz. The superimposed ripple voltage e1 (AC component) is actually generated not only by the rectifier 10, but also by inflow from an inverter circuit such as a digital protection control panel power supply device. The ripple appears as a voltage, and the current is generated by the difference between the power supply voltage and the storage battery voltage, so the current to the storage battery 14 is likely to cross zero. The magnitude of the ripple voltage e1 is set with reference to the actual (measured) voltage that appears when superimposed during floating charging. The zero cross current causes the anode (lead portion) of the storage battery 14 to peel off, shortening the life of the storage battery 14. The zero cross current causes the storage battery 14 to repeatedly charge and discharge in a short period of time, causing the volume of the anode (lead portion) to expand and contract in a short period of time, which affects the progression of anode peeling. On the other hand, the frequency of the ripple voltage e1 originates from three-phase full-wave rectification (three-phase forward bridge, six-phase rectifier circuit) that is often used in battery chargers for power substations. That is, with three-phase full-wave rectification, it is known that an AC voltage six times the fundamental frequency (60 Hz in areas where the commercial power frequency is 60 Hz) is superimposed as the ripple voltage e1. If the rectification method is a single-phase mixed bridge, single-phase forward bridge, or single-phase bridge, an AC with twice the fundamental frequency (120Hz) is superimposed. In the case of a three-phase mixed bridge, an AC with three times the fundamental frequency (180Hz) is superimposed. In the case of a double three-phase bridge, an AC with 12 times the fundamental frequency (720Hz) is superimposed.

[0026] As a result of the simulation shown in FIG. 8, a ripple voltage (peak-to-peak value) of 700 mV is generated in the storage battery 14 and is superimposed on the DC voltage, and a ripple current (peak-to-peak value) of 30 A is generated. For a floating charge current of 1A, a ripple current (peak-to-peak value) of 30A occurs, so that the current to the storage battery 14 crosses zero.

[0027] FIG. 9 is a diagram relating to a simulation of the circuit of the storage battery device 1 after the saturable reactor device 12 is connected. That is, an additional reactor L1 of 2 mH and an internal resistor R3 of 10 mΩ corresponding to the saturable reactor device 12 are added to the circuit of FIG.

[0028] 9, a ripple voltage (peak-to-peak value) of 5.2 mV is generated superimposed on the DC voltage in the storage battery 14, and a ripple current (peak-to-peak value) of 0.22 A is generated. That is, by installing the saturable reactor device 12, the ripple current (peak-to-peak value) is reduced from 30 A to 0.22 A. For a floating charge current of 1 A, a ripple current (peak-to-peak value) of 0.22 A occurs, so that the zero crossing of the current to the storage battery 14 is suppressed.

[0029] In other words, in a substation in a situation corresponding to Figure 8, if the saturable reactor device 12 is installed using terminals T2 and T5, the zero crossing of the current to the storage battery 14 is suppressed, anode peeling of the storage battery 14 is suppressed, and the life of the storage battery 14 is extended. Furthermore, the current from the storage battery 14 for the DC load D during a power outage is a large current (for example, 10 A or more) compared to the floating charge current, and this causes the saturable reactor device 12 (first reactor 24) to become conductive due to saturation of the saturable reactor device 12. Therefore, the effect of the saturable reactor device 12 on the operation of the storage battery 14 during a power outage is suppressed. In addition, in the saturable reactor device 12, the reactor to be added can be changed to 1 mH or 4 mH depending on the situation by changing the connection mode to the terminal block 22. For example, in a substation in a situation corresponding to Figure 8, if a 4 mH reactor is added, the ripple current is reduced at a reduction rate twice that of the 2 mH reactor (Figure 9).

[0030] <Actions, Effects, etc.> The above-described storage battery device 1 and the like provide the following advantageous effects. That is, the saturable reactor device 12 for a storage battery includes a first reactor 24 and a second reactor 26 which are reactors that saturate for a current exceeding a predetermined value, rectifier-side terminals T2, T3 connected to either the first reactor 24 or the second reactor 26 and connected to the rectifier 10, and battery-side terminals T4 to T6 connected to either the first reactor 24 or the second reactor 26 and connected to the storage battery 14. Therefore, if the saturable reactor device 12 is connected to the rectifier 10 and the storage battery 14, the zero crossing of the floating charging current is suppressed, and the life of the storage battery 14 is extended. Also, since the saturable reactor device 12 is an independent device, it is easy to introduce a device for suppressing the zero crossing, and it can be easily introduced into an existing storage battery device. Furthermore, the influence on the discharge operation of the storage battery 14 due to the saturation of the first reactor 24 and the second reactor 26 is suppressed.

[0031] Furthermore, the current values ​​at which the first reactor 24 and the second reactor 26 are saturated are both set to 1 A or more. Moreover, the reactor capacity before saturation in the saturable reactor is set to 1 mH or more. Thus, the saturable reactor device 12 is more compatible with popular rectifiers 10 and batteries 14 .

[0032] In addition, the pre-saturation reactors in the first reactor 24 and the second reactor 26 are set in a state in which a plurality of reactors are set, with some being selected. Also, a plurality of terminals T2, T3 on the rectifier side and a plurality of terminals T4 to T6 on the storage battery side are provided, and the pre-saturation reactors are set by selecting the terminals T2 to T6 to be connected. That is, the pre-saturation reactor is set to 1 mH by selecting the terminals T2, T5, and the pre-saturation reactor is set to 4 mH by selecting the terminals T3, T6. Therefore, the reactor before saturation can be adjusted according to the state of at least one of the rectifier 10 and the storage battery 14.

[0033] On the other hand, the storage battery device 1 includes the above-mentioned saturable reactor device 12 and a storage battery 14. Therefore, the storage battery device 1 in which the life of the storage battery 14 is extended is provided. On the other hand, an uninterruptible power supply includes the above-mentioned storage battery equipment 1. Thus, an uninterruptible power supply in which the life of the storage battery 14 is extended is provided.

[0034] In addition, in the control method for the storage battery 14, the first reactor 24 and the second reactor 26, which are reactors that saturate for currents exceeding a predetermined value set to be equal to or greater than the DC current during floating charging of the storage battery 14, are connected in series between the rectifier 10 and the storage battery 14 with the size of the reactor set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charge to be smaller than the DC voltage during floating charging. Thus, the storage battery 14 is controlled so as to suppress zero crossing of the floating charge current and extend its life. Also, the storage battery 14 is controlled so as to suppress the effect of saturation of the first reactor 24 and the second reactor 26 on the discharging operation. Furthermore, the first reactor 24 and the second reactor 26 are connected to the rectifier 10 and the storage battery 14 via the terminals T2 to T6, respectively. Therefore, it is easy to introduce control for suppressing zero crossings, and it can be easily introduced into existing storage battery equipment. [Explanation of symbols]

[0035] 1·· Battery storage equipment (uninterruptible power supply), 10·· Rectifier, 12·· Saturable reactor equipment (for battery), 14·· Battery, 24·· First reactor (saturable reactor), 26·· Second reactor (saturable reactor), T2, T3·· Rectifier side terminals, T4, T5, T6·· Battery side terminals.

Claims

1. A saturable reactor that is a reactor that saturates when a current exceeds a predetermined value that is set to be equal to or greater than the direct current during float charging of a storage battery; a rectifier side terminal connected to the saturable reactor and connected to a rectifier; a battery side terminal connected to the saturable reactor and connected to a battery; It is equipped with The size of the reactor is set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charge to be smaller than the DC voltage during the floating charge. A saturable reactor device for a storage battery.

2. The predetermined value is set to 1 A or more.

2. The saturable reactor device for a storage battery according to claim 1.

3. The reactor capacity before saturation in the saturable reactor is set to 1 mH or more.

3. The saturable reactor device for a storage battery according to claim 1 or 2.

4. A saturable reactor device for a storage battery according to any one of claims 1 to 3, The storage battery; Equipped with A storage battery device characterized by:

5. The storage battery device according to claim 4. Equipped with An uninterruptible power supply device.

6. A saturable reactor, which is a reactor that saturates for a current exceeding a predetermined value set to be equal to or greater than the DC current during floating charging of the storage battery, is connected in series between the rectifier and the storage battery, with the size of the reactor set to suppress the peak-to-peak value of the AC voltage superimposed on the floating charge to be smaller than the DC voltage during the floating charge. A method for controlling a storage battery.

7. The saturable reactor is connected to the rectifier and the storage battery via respective terminals.

7. The method for controlling a storage battery according to claim 6.

Images