JP6056205B2 - Battery power supply charge / discharge control device - Google Patents

Description

  The present invention relates to an electric drive system in which a load such as an electric motor is driven by a hybrid power source including a battery power source configured by a rechargeable battery and a normal power source configured by a power generator that charges the battery of the battery power source. The present invention relates to a charging / discharging control device for a battery power supply in a mode in which power is supplied to a load while the battery power is being charged by the normal power supply and a mode in which the normal power supply is stopped and power is supplied from only the battery power supply to the load. .

  For example, in an electric drive system using a hybrid power source such as an electric propulsion ship, a mode in which the propulsion motor and inboard auxiliary equipment are operated by charging the battery of the battery power source with a normal power source constituted by a power generator and There is a mode in which the generator is stopped and power is supplied only from the battery power source.

  Since such an electric drive system requires a large-capacity power source, the battery power source of the hybrid power source has a small capacity, so that the capacity can be increased by configuring a large number of battery elements connected in series and parallel. ing.

  FIG. 6 shows a conventional example of a control circuit that performs charge / discharge control of such a battery power source (see Patent Document 1).

  FIG. 6 is a block circuit diagram showing the configuration of the electric drive system of the electric propulsion vessel.

  The hybrid power source 1 includes a battery power source 2 and a normal power source 3. In order to make the battery power supply 2 a large-capacity power supply, a plurality of (n) rechargeable battery elements b1 to bn such as lithium ion batteries are connected in series to form an assembled battery B, and this assembled battery B1 ˜Bm is configured by connecting a plurality (m) sets in parallel.

  The normal power supply 3 includes an AC generator G driven by a prime mover DE such as a diesel engine and a rectifier REC that converts AC power output from the generator into DC power. Battery power source 2 and normal power source 3 are connected in parallel to the bus of hybrid power source 1 via switches S1 and S2, respectively.

  Power is supplied from the thus configured hybrid power supply 1 to the propulsion device 4 having the power converter INV constituting the inverter and the AC propulsion motor M driven by the inverter via the switch S3. The propulsion motor M propels the ship by driving a propeller (not shown) here.

  In a normal operation mode in which the battery power supply 2 is charged from the normal power supply 3 and is operated by supplying power to the propulsion device 4 and other loads not shown here, the switches S1, S2 and S3 are turned on, and the normal power supply 3 Is supplied to the battery power source 2 and the propulsion device 4.

At this time, the charge / discharge control unit 5 controls the output of the generator G according to the state of charge of the battery power supply 2. The charging control unit 5 is a constant voltage charging control means AVR for controlling the generator G so that the output voltage of the generator G becomes a constant voltage in order to charge at a constant voltage, and a battery power source for charging at a constant current Constant current charging control means ACR for controlling the generator G so that the charging current IB of the battery is constant, and the generator G is controlled so that the charging power PB of the battery power source 2 is constant for charging with constant power. Constant power charge control means APR is provided.

  The constant voltage charge control means AVR compares the charge voltage set value VBs set in the charge voltage setter 20 with the terminal (output) voltage VBi of the battery power supply 2 detected by the voltage detector 9 to obtain a deviation between the two. The voltage adjustment calculator 36 calculates the voltage command VGs for the generator G that makes this deviation zero.

  Similarly, the constant current charge control means ACR compares the charge current set value IBs set in the charge current setter 21 and the charge current detected value IBi detected by the current detector 8 of the battery power source, and the difference between the two. The voltage command value VGs for the generator G that makes this deviation zero is calculated by the current adjustment calculator 37 by calculation.

  Further, the constant power charging control means APR is set in the charging power setting unit 22 and the charging power set value PBs, and the power calculator 25 detects the battery power supply voltage detection value VBi and the current detector 8. The charging power detection value PBi of the battery power source obtained by multiplying the charging current detection value IBi detected by the above is compared to obtain a deviation between the two, and the generator G that makes this deviation zero by the power adjustment calculator 38 Is obtained by calculation.

  The voltage command VGs calculated by the constant voltage charge control means AVR, constant current charge control means ACR and constant power charge control means APR is selected by the charge mode switch 39 to control the field FLG of the generator G. It is given to the excitation adjustment device FLC.

  In the voltage regulator 48, the excitation adjustment device FLC compares the voltage command VGs given from each charging control means with the detected value VGi of the output voltage of the rectifier REC detected by the voltage detector 10, and determines the deviation between the two. The current command value IGs to the generator G that becomes zero is calculated and supplied to the current regulator 50. In the current regulator 50, the current command value IGs is compared with the generator output current IGi detected by the current detector 11, and the field current command to the field GF of the generator where the deviation between the two is zero. The value Ifs is calculated and given to the field controller 51.

The field control device 51 controls the field current IfG supplied to the field GF to a current corresponding to the field current command value Ifs. As a result, the output voltage VGi of the generator G detected by the voltage detector 10 is adjusted to be the voltage command value VGs given from each of the charge control means, and the battery charging can be optimally controlled.

  However, such a conventional charge / discharge control device does not monitor the charging voltage of each battery element (also referred to as a single cell) constituting the battery power supply, so that the constant current charging mode or the constant power charging is performed. When charging is performed in the mode, it is expected that the charging voltage exceeds the prescribed upper limit value depending on the battery elements constituting the assembled battery due to variations in the characteristics of the battery elements, and an overcharged state is expected. In addition, since the assembled battery is configured by connecting a large number of battery elements (single cells) in series and parallel, some of the single cells in the assembled battery are undercharged, overcharged, or overdischarged due to charging / discharging of the battery power supply. Expected to be in a state.

  Further, in a battery power source configured by connecting a plurality of sets of battery packs in parallel, when the battery pack voltage exceeds an upper limit value or a lower limit value in order to protect the battery pack from overcharge and overdischarge, The protection from the battery power supply has already been performed (see Patent Document 2).

  Furthermore, in Patent Document 3, when the voltage of the assembled battery is going to exceed the lower limit during power feeding from the battery power source, the load is limited so that the assembled battery voltage does not drop below the lower limit. Protecting the battery pack of a battery power source is also performed.

  However, even in these conventional apparatuses, overcharge and overdischarge of individual battery elements in the assembled battery constituting the battery power source, that is, single cells, are not performed.

JP 2012-050294 A JP 2005-168259 A JP 2008-067525 A

  As described above, the battery power source of the hybrid power source of the electric drive system has a large capacity by connecting many rechargeable battery elements such as lithium ion batteries in series and parallel. In particular, in the case of a lithium ion battery, it is known that deterioration of characteristics rapidly proceeds due to overcharge and overdischarge, and the life is shortened. For this reason, during the charging operation of a battery power source composed of lithium ion batteries, the battery voltage of both the unit cell and the assembled battery composed by connecting a plurality of these in series and in parallel must not exceed the prescribed upper limit value. Charge and discharge operation is prevented by preventing charging and overvoltage, and also preventing discharge and overvoltage by preventing the battery voltage of both single cells and assembled batteries from dropping below the specified lower limit. The progress of the deterioration of the characteristics of the single battery is suppressed, and the life of the battery power source can be extended.

  In view of the above, the present invention, in particular, causes the deterioration of the characteristics of some of the unit cells constituting the assembled battery to affect the life of the entire assembled battery. It is an object of the present invention to provide a battery power source having a long life by monitoring and performing appropriate restriction control of the single cell during the charge / discharge operation and suppressing characteristic deterioration.

In order to solve the above-described problems, the present invention provides a battery power source configured by connecting a plurality of battery packs configured by connecting a plurality of rechargeable battery elements (single cells) in series, and a plurality of battery packs connected in parallel. In an electric drive system in which a load of an electric motor is driven by a hybrid power source including a normal power source configured by a power generation device that charges a battery of the power source,
Battery voltage detecting means for detecting the voltage (unit cell voltage) of each battery element (unit cell) and the voltage of the assembled battery (assembled battery voltage) constituting the battery power source when charging and discharging the battery power source;
Voltage determination means for comparing the cell voltage and the assembled battery voltage detected by the battery voltage detection means with the cell upper limit set voltage or the cell lower limit set voltage and the battery pack upper limit set voltage or the battery pack lower limit set voltage, respectively.
An assembled battery voltage converting means for obtaining an assembled battery converted voltage by multiplying the unit cell voltage detected by the battery voltage detecting means by the number of cells connected in series in the battery power supply;
During charging of the battery power supply, when said single cell voltage or the battery pack voltage exceeds the single battery upper limit set voltage or the battery pack upper limit set voltage, the on thus assembled battery referred voltage obtained as the assembled battery voltage converting means either higher voltage the unit cell voltage and the voltage of the battery module both or either one of voltages above unit cell upper limit set voltage or battery pack limit based on the of the detected voltage of the battery module in the battery voltage detection means Means for limiting a charging voltage supplied from the normal power supply so as not to exceed a set voltage;
During discharge of the battery power supply, when said single cell voltage or the battery pack voltage exceeds the unit cell lower limit setting voltage or the battery pack lower limit setting voltage, the on thus assembled battery referred voltage obtained as the assembled battery voltage converting means comparing the assembled battery voltage detected by the battery voltage detection means, whichever is lower the unit cell voltage and the battery pack voltage based on the voltage of both or one of voltage the unit cell lower limit setting voltage Or means for limiting the power supplied from the battery power source to the load so as not to exceed the battery pack lower limit setting voltage,
It is characterized by providing.

In the present invention, when both or either of the assembled battery conversion voltage and the assembled battery voltage exceed the upper limit set voltage or the lower limit set voltage , the assembled battery of the set having the battery is disconnected from the power supply circuit. This can be protected.

Further, good to be able record and display the time arrival date of the single cells and a battery both cell number and cell voltage and the upper limit set voltage or lower limit setting voltage, constituting the battery power source in the present invention .

  According to the present invention, not only the voltage of the assembled battery of the battery power source configured by connecting a plurality of assembled batteries configured by connecting a plurality of battery elements (single cells) in series, but also the individual batteries constituting the assembled battery The voltage of the battery element (single cell) is detected, and the assembled battery voltage, the unit cell voltage, or the assembled battery conversion voltage obtained by converting this unit cell voltage into the assembled battery equivalent voltage does not exceed the preset upper limit voltage or lower limit voltage. In addition, since the charging voltage or discharging power is limited, overcharging and overdischarging of not only the assembled battery but also the single cell can be suppressed, so that the life of the battery power source can be extended.

The block circuit block diagram which shows the basic composition of the Example of the charging / discharging control apparatus of this invention. The charge characteristic view used for description of the charge operation of this invention. The figure which shows the voltage change of each battery element (unit cell) of the assembled battery used for description of the charging operation of the battery power supply in this invention. The figure which shows the voltage change of each battery element (unit cell) of the assembled battery used for description of discharge operation of the battery power supply in this invention. The block circuit block diagram which shows the structure of the application example of the charging / discharging control apparatus of this invention. The block circuit block diagram which shows the structure of the conventional charging / discharging control apparatus.

  Embodiments of the present invention will be described with reference to the embodiments shown in the drawings.

  FIG. 1 shows a basic circuit configuration of a charge / discharge control apparatus according to Embodiment 1 of the present invention.

  1 has basically the same configuration as the conventional apparatus shown in FIG. 6, and therefore, the same components are indicated by the same reference numerals and the description thereof is omitted. .

  The charge control device according to the present invention is different from the conventional device in that a battery voltage monitoring control unit 80 for monitoring and controlling the voltages of both individual battery elements (unit cells) constituting the battery power source and the assembled battery is provided. .

  The battery voltage monitoring control unit 80 detects each voltage from each terminal of a plurality (n) of battery elements (unit cells) b1 to bn connected in series constituting the assembled battery B of the battery power source 2. A unit cell voltage detector 63 is provided. The unit cell voltage detector 63 sequentially scans and selects a plurality of unit cells constituting the assembled battery in synchronization with the clock pulse CP generated by the clock pulse generator 60, and detects the voltage Vbn of each unit cell bn. To do.

  The voltage VB of the assembled battery B of the battery power source 2 is detected by a voltage detector 9 connected in parallel therewith.

  The unit cell voltage Vbn detected by the unit cell voltage detector 63 is determined by the voltage determination unit 64 in the unit cell upper limit voltage setter 61 and the unit cell lower limit voltage setter 62. The magnitude relationship with VbL is compared and determined. The upper limit determination unit 64U of the voltage determination unit 64 outputs the compared unit cell voltage Vbn as the holding voltage VbUn as it is when the unit cell voltage Vbn is equal to or higher than the unit cell voltage upper limit value VbU (Vbn ≧ VbU). The voltage is held in the upper limit holding unit 65U of the voltage holding unit 65. The lower limit determination unit 64L of the voltage determination unit 64 outputs the unit cell voltage Vbn as the holding voltage VbLn as it is when the unit cell voltage Vbn is equal to or lower than the set unit cell voltage lower limit value VbL (Vbn ≦ VbL), and holds the voltage. The lower limit holding part 65L of the part 65 is held.

  Similarly, the assembled battery voltage VBi detected by the voltage detector 9 is obtained by the voltage discriminating unit 71 at the assembled battery upper limit voltage setter 35 and the assembled battery lower limit voltage setter 36. The magnitude relationship with the lower limit voltage VGL is compared and determined. The upper limit determination unit 71U of the voltage determination unit 71 outputs the compared assembled battery voltage VBi as the holding voltage VGUg as it is when the assembled battery voltage VBi is equal to or higher than the set assembled battery upper limit voltage VGU (VBi ≧ VGU). The upper limit holding unit 70U of the holding unit 70 is held. When the assembled battery voltage VBi is equal to or lower than the set assembled battery lower limit voltage VGL (VBi ≦ VGL), the lower limit determining unit 71L of the voltage determining unit 71 outputs the assembled battery voltage VBi as it is as the holding voltage VGLg, and holds the voltage. The lower limit holding part 70L of the part 70 is held.

Upper limit voltage VbU and lower limit value VbL installed in upper limit setting unit 61 and lower limit setting unit 62 of cell, and upper limit of unit cell voltage held in upper limit holding unit 65 U and lower limit holding unit 65 L of voltage holding unit 65 The holding voltage VbUn and the lower limit holding voltage VbLn are converted into voltages equivalent to the assembled battery voltage by the assembled battery conversion unit 66, respectively.

This conversion is performed by multiplying the voltage value of the unit cells by the number (n) of the unit cells connected in series as follows in each of the conversion units 66Us, 66Ud, 66Ls, and 66Ld.
(1) Set upper limit voltage conversion unit 66Us
Battery set conversion upper limit voltage VbUB = unit cell set upper limit voltage VbU x number of unit cells connected in series n
(2) Holding upper limit voltage conversion unit 66Ud
Battery pack equivalent retention upper limit voltage VbU1 = unit cell retention voltage VbUn x number of unit cells connected in series n
(3) Setting lower limit voltage conversion unit 66Ls
Battery set conversion lower limit voltage VbLM = Cell set lower limit voltage VbL × Number of cells connected in series n
(4) Holding lower limit voltage conversion section 66Ld
Battery pack equivalent retention lower limit voltage VbL1 = unit cell retention voltage VbLn x number of unit cells connected in series n
The battery cell converted holding upper limit voltage VbU1 and the battery pack converted holding lower limit voltage VbL1 of the unit cell voltage thus obtained are the battery pack upper limit holding voltage output from the voltage holding unit 70 in the voltage determination units 68 and 69, respectively. The magnitude relation with VBU2 and battery pack lower limit holding voltage VBL2 is compared and determined. The voltage discriminating unit 68 generates a discrimination output bnU when the converted voltage becomes large as VbU1> VBU2, and the voltage discriminating unit 69 generates the discrimination output MnD when the converted voltage becomes small as VbL1 <VBL2.

  The discrimination output bnU of the voltage discrimination unit 68 is given as a voltage limit command to the limit calculation unit 44, and the discrimination output MnD of the voltage discrimination unit 69 is given as a speed limit command to the speed control unit 14 that controls the speed of the propulsion device 4. It is done. When the limit calculation unit 44 receives the determination output bnU from the voltage determination unit 68, the excitation adjustment of the charge / discharge control unit 5 uses the assembled battery conversion set upper limit voltage VbUB received from the set upper limit voltage conversion unit 66 Us of the assembled battery conversion unit 66. The limiter VGL2 inserted in the generator voltage command circuit of the device FLC is given as a limit value that defines the upper limit of the generator voltage command VGs.

  The voltage discriminating units 64 and 71 are provided with setting functions 61, 62, 35, and 36, and also have a function of detecting 5% and 10% exceeding the lower limit set value. When the upper and lower limit set values are exceeded by 10% or more, voltage abnormality alarm outputs VbAL1 and VbAL2 are generated.

  The supervisory control unit 78 receives the alarm outputs VbAL1 and VbAL2 of the voltage abnormality, the discrimination outputs bnU, MnD, etc. of the voltage discrimination units 68 and 69 and receives the battery numbers and batteries of both the unit cell and the assembled battery constituting the battery power source. It records and displays the operation status such as arrival time and alarms at the voltage, upper limit voltage or lower limit voltage, and provides them for monitoring the operating status of the operator.

Next, the operation of the apparatus of the present invention configured as described above will be described.
[Charging operation]
As in the conventional apparatus, the constant charging mode is selected by the charging mode switch 39. Here, the charging operation in the constant current charging mode will be described with reference to FIG. In FIG. 2, the cell voltage Vbn and the assembled battery voltage VBi are shown as a percentage voltage with respect to the rated voltage so that the charging characteristics of the cell and the assembled battery can be displayed by the same characteristic line, and the assembled battery voltage is attached with (). it's shown.

  As shown in FIG. 2, the charging current IBi is IB1 at the first stage (time t0 to t1), IB2 at the second stage (time t1 to t2), and IB3 at the third stage (time t2 to t3). As the charging progresses, charging is performed by gradually reducing the charging current, and the charging proceeds to the fourth stage charging under the condition that the assembled battery voltage VBi increases to VBid1 at time t3. In the fourth stage of this final charging area, the charging current is set to a minute current IB4 and the battery is charged to full charge.

  When there is little characteristic deterioration of all the battery elements (single cells) of the assembled battery and the charging characteristic as shown by the characteristic line A is shown, the battery voltage rises from VBid2 with time and the cell ends at time t7. The voltage reaches VbU and the assembled battery end voltage VBU2 (= VGU) and is fully charged.

  When the characteristic deterioration or variation occurs in the unit cell and the characteristic is slightly deteriorated as shown by the characteristic line B, it passes the upper limit voltage VbU at time t5 and rises to VbiOV1 at time t7.

  When the assembled battery voltage is VBU2 = VGU and the cell voltage is going to exceed VbU1 = VbU, a voltage limiting operation is applied to the generator G so as not to exceed it, and the charging current is limited to IB5 indicated by a dotted line. .

  Further, when the assembled battery voltage VBU2 reaches the upper limit over-protection level VBiOV of VGU + δ2, for example, exceeding 10% of the assembled battery upper limit set voltage VGU, and the unit cell voltage VbU1 exceeds, for example, 10% of the unit cell upper limit set voltage VbU When the upper limit excess protection level VBiOV of VbU + δ2 is reached, the battery is protected by stopping charging at this time (t6).

  It is difficult to detect from the terminal voltage of the battery pack that the unit cell voltage exceeds the upper limit value and the lower limit value. This is because the voltage change of some of the unit cells constituting the assembled battery is minute compared to the assembled battery voltage, and the unit cell voltage varies due to the variation of the unit cell characteristics. For this reason, it is necessary to detect the voltage of the single cell individually and to perform voltage limit control of the generator during charging to prevent overcharging.

  Further, when the deterioration of the characteristics of the single battery progresses and the characteristics are significantly deteriorated as shown by the C characteristic line, the battery pack converted voltage VbU1 and the battery pack voltage VBU2 of the single battery voltage are equal to the upper limit setting voltage VGU as described above. Even if the voltage limit control of the generator is performed so that it does not exceed, the voltage rises to a voltage exceeding VGU + δ2, which exceeds 10% of the upper limit value at time t4, and thus protection such as charging stop is performed here.

  The operation of the battery voltage monitoring controller 80 during such a charging operation will be described with reference to FIG.

  FIG. 3 shows, in a time series manner, changes in individual detection voltages of a plurality (n) of battery elements (single cells) b1 to bn constituting the assembled battery during the charging operation.

  The cell voltage detector 63 shown in FIG. 1 is synchronized with the clock pulse CP supplied from the clock pulse generator 60, and the voltage Vb1 of the cell b1 at the time t1 in FIG. 3 and the voltage of the cell b2 at the time t2. The voltage Vb3 of the cell b3 at the time Vb2, t3,... The voltage Vbn-1 of the cell bn-1 at the time tn-1, the voltage Vbn of the cell bn at the time tn, and the cells b1 to bn as the voltage Vbn of the cell bn. The voltage Vbn of each unit cell is detected by sequentially scanning and selecting. The detected unit cell voltage Vbn is output to the voltage determination unit 64. The voltage determination unit 64 outputs the cell voltage at that time as the determination output VbUn when Vbn ≧ VbU as compared with the set upper limit voltage VbU each time.

  The determination output VbUn is held in the upper limit holding unit 65U of the voltage holding unit 65. The unit cell voltage VbUn held in the holding unit 65U is converted by the assembled battery conversion unit 66 into a voltage VbU1 equivalent to the assembled battery voltage by multiplying the number of unit cells connected in series by n. The assembled battery conversion voltage VbU1 obtained by the assembled battery conversion unit 66 is applied to the voltage determination unit 68, where the magnitude relation is compared with the assembled battery determination voltage VBU2 applied from the voltage holding unit 70U, and VbU1> VBU2 At this time, the discrimination output bnU is output to the limit calculation unit 44.

  Here, when the battery pack upper limit voltage VBU2 is compared with the battery pack conversion upper limit voltage VbU1 obtained by multiplying the battery voltage by n, the battery pack conversion lower limit voltage VbU1 is a cell in which a part of the battery voltage has increased. Since the voltage is a voltage converted into an assembled battery, the single cell converted upper limit voltage signal VbU1 is higher than the assembled battery upper limit voltage VBU2 that is the assembled battery voltage itself (VbU1> VBU2).

  Therefore, in most cases, the voltage determination unit 68 selects the assembled battery conversion upper limit voltage VbU1 and supplies it to the limit calculation unit 44 as the voltage limit command bnU.

  The limit calculation unit 44 provides the command limiter VGL2 with the limit value VbUB for the generator command voltage whose cell voltage matches the limit voltage VbU, and performs the voltage limit control of the generator. As a result, the output voltage of the generator G is limited to a voltage such that the unit cell voltage Vbn matches the unit cell upper limit set voltage VbU.

3, unit cell bn voltage Vbn is a single battery set upper limit voltage between t ₁ ~t ₂ time points smaller T1 period than VbU and t ₂ ~t ₃ time between passes without controlling anything but a single Between time t3 and time t4 when the battery voltage Vb3 coincides with the unit cell upper limit setting voltage VbU and Vbn ≧ VbU, the voltage determination unit 64 outputs the determination output VbUn, and is held as the hold 1 in the voltage holding unit 65U. In the conversion unit 66, the output voltage restriction control of the generator G as described above is performed, for example, by conversion to the assembled battery equivalent voltage VbU1, and the voltage Vb3 of the unit cell b3 does not exceed the set upper limit voltage VbU. To be done.

  Since the voltage discriminating unit 64 discriminates that the voltage Vbn-1 of the cell bn-1 has reached the upper limit voltage VbU between the time points tn-1 and tn of the T1 cycle, and provides the discriminating output VbUn to the voltage holding unit 65. The voltage holding unit 64 resets the holding 1 and updates the holding voltage to the holding 2. When a new holding voltage VbUn is output from the voltage holding unit 64, the voltage limit control of the generator G is performed as described above.

  The voltage Vbn of the unit cell bn between the time t1 of the T1 cycle and the time t1 of the T2 cycle is Vbn <VbU, and thus this period is passed as it is. Since the unit cell voltages Vb1 and Vb2 are both smaller than the upper limit set voltage VbU between the time points t1 to t2 and the time points t2 to t3 in the T2 cycle, these periods are passed as they are. When the voltage determination 64 determines that the voltage Vb3 of the cell b3 reaches VbU + δ1 which is about 5% higher than the upper limit setting voltage VbU between the time points t3 and t4 of the T2 cycle, the clock pulse stop signal St is output to the clock pulse generator 60. Then, the operation of the clock pulse generator 60 is temporarily stopped, the scanning selection operation of the unit cell voltage detector 63 is temporarily stopped, the operations of the voltage holding units 65 and 70 are temporarily stopped, and the holding voltage VbUn is reset.

  The voltage Vb3 of the unit cell b3 is sequentially applied to the voltage discriminating unit 64⇒the voltage holding unit 65⇒the assembled battery converting unit 66⇒the voltage discriminating unit 68⇒the command limiting unit 44⇒the command limiting unit VGL2, and the assembled battery converted voltage of the unit cell b3 A control for limiting the generator G command to the limit signal BnU1G by limiting the generator voltage command VGs given from the charge control means to the excitation adjustment device FLC by the limit signal BnU1G where VbU3 matches the assembled battery conversion upper limit voltage VbUB. I do.

At this time, since the single-cell voltage Vb3 is increased to limit the voltage VBU + .delta.1, limiting calculation unit 44 limits by receiving discrimination output bnU for canceling .delta.1 minutes + from the voltage discriminating unit 68 signals BnU1G (= VbU-δ1 ) Is output to the command limiter VGL2. The generator voltage limit command signal BnU1G calculated so that the voltage Vb3 of the cell b3 matches the upper limit voltage VbU is once lowered to BnU1G = VbU−δ1 at the point t3 of the T2 cycle, and gradually toward the point t4. The voltage is raised to BnU1G = VbU and reaches the point t4 in the T2 cycle.

  Following this limit signal, the generator voltage gradually decreases from the point t3 of the T2 cycle, reaches the point t4, and the voltage Vb3 of the unit cell b3 matches the upper limit set voltage VbU.

  When the cell voltage Vb3 decreases to coincide with VbU, the voltage discriminating unit 64 detects the coincidence, turns off the clock pulse stop signal St, restarts the operation of the clock pulse pulse generator 60, and outputs the discriminant output VbUn. In the voltage holding unit 65U, the holding 2 that has been held so far is reset and a new holding 3 is set. This holding voltage VbUn is the voltage of the generator G so that the voltage Vb3 of the cell b3 does not exceed the upper limit set voltage VbU via the assembled battery conversion unit 66⇒voltage determination unit 66⇒limit calculation unit 44⇒command limiter VGL2. Perform limit control.

  In this way, if the cell voltage Vbn <the upper limit set voltage VbU, the limit control is passed, and if Vbn ≧ VbU, the voltage holding VGs to the generator G is updated by updating the voltage holding for each detection. Is limited to the limit command value BnUG and the voltage limit control of the generator is performed so that the unit cell voltage Vbn does not exceed the upper limit set voltage VbU.

  When the cell voltage Vb3 rises to VbU + δ2 exceeding 10% of the upper limit voltage VbU as at the point t3 of the T3 cycle, or the voltage Vb1 of the cell b1 is the upper limit voltage VbU as at the point t1 of the T4 cycle. When the voltage discriminating unit 64 detects that the voltage drops more than 10% and becomes VbU-γ, an alarm signal VbAL1 is generated as an excessive voltage increase or excessive voltage decrease of the unit cell voltage, and the monitoring control unit 78 Send to.

  When the monitoring control unit 78 receives the warning signal VbAL1, the monitoring control unit 78 issues a warning and performs protection control such as shutting off the switch S1 to stop the charging of the battery power supply or stopping the charging operation of the generator.

  Further, every time the unit cell voltage Vbn reaches the upper limit voltage VbU, the voltage discriminating unit 64 outputs the discrimination output signal VbUn to update the holding voltage of the voltage holding unit 65 as 1 → hold 2 → hold 3 → hold 4; Based on the discrimination output bnU of the voltage discriminating unit 68 and the signal Sn indicating the battery number of the voltage discriminating unit 64, the supervisory control unit 78 advances the operation of the unit cell numbers b1... Bn, the unit cell voltage Vbn, the upper limit voltage arrival time, etc. Record and display status data. Data indicating the operation state displayed on the monitoring control device 78 is monitored by an operator.

  The protective operation of the unit cell has been described above. The protective operation of the assembled battery voltage will be described next.

  The upper limit voltage VGU of the assembled battery voltage VG is set in the upper limit voltage setter 35, and the lower limit voltage is set in the lower limit voltage setter 36.

  When the battery pack B is charged in a constant current charging mode with a multistage constant current, the charging current IBi and the charging voltage VBi change as shown in FIG. In FIG. 2, the value related to the assembled battery is indicated by () because the characteristics of the cell are also shown.

  When the end charging operation of the fourth stage is started from the point t3 in FIG. 2, the assembled battery voltage increases from VBid2 toward VBU2 (= VGU).

  Characteristic line A shows the charging characteristics when there is little variation in the characteristics of the cells constituting the assembled battery and the characteristic deterioration is small, and the charging characteristics when the characteristic deterioration slightly progresses depending on the operating time, charge / discharge cycle, etc. In B, the charging characteristic when the characteristic deterioration has considerably progressed is indicated by a characteristic line C.

  If the charging characteristic of the assembled battery B is the characteristic indicated by the characteristic line A, the assembled battery voltage reaches VBU2 (= the upper limit voltage VGU) at the time t7 when charging is completed.

  When the charging characteristic of the assembled battery B is the characteristic indicated by the characteristic line B, the battery voltage VBi reaches the upper limit set voltage VBU2 = VGU at the point t6 before reaching the time t7, and further, the charging is continued until the time t7. Battery voltage VBi reaches VBiOV1 and enters an overcharge state.

Therefore, the voltage discrimination unit 71 detects that the assembled battery voltage VBi has reached the upper limit set voltage VGU set in the upper limit voltage setter 35, outputs a discrimination output VGUg, gives it to the voltage holding unit 70U, and holds it there. . The voltage holding unit 70U supplies the held determination output VGUg to the voltage determination unit 68 as the assembled battery holding voltage VBU2. The voltage determination unit 68 generates a determination output bnU and supplies it to the limit calculation unit 44 if VbU1 <VBU2 as compared with the assembled battery converted holding voltage VbU1 provided from the assembled battery conversion unit 66 . This ensures that the output voltage VG of the generator G, the voltage VBi of the battery module B is controlled so as not to exceed the upper limit voltage VGU, overcharge of the battery pack B is inhibited.

  This operation is an operation when the assembled battery voltage reaches the upper limit voltage and the unit cell voltage does not reach the upper limit voltage. If the assembled battery conversion holding voltage VbU1 and the assembled battery holding voltage VBU2 are detected at the same time, the unit cell The voltage detection control of the generator is performed by preferentially selecting the voltage detection VbU1.

  Further, when the voltage determination unit 71 detects that the assembled battery voltage VBi exceeds VGU + δ2 that exceeds 10% of the upper limit voltage VGU, the voltage determination unit 71 generates an alarm signal VbAL2 and gives it to the monitoring control unit 78. The monitoring control unit 78 displays and records this alarm signal VbAL2 and issues an alarm, and turns off the assembled battery switch S1 to disconnect the assembled battery from the power supply bus of the hybrid power supply, or stops charging the assembled battery, or Stop the generator and stop charging the battery pack.

  Even when the assembled battery is charged with the characteristic of the characteristic line C, the assembled battery voltage VBi passes through the VBiOV at the point t4 as in the case of being charged with the characteristic of the characteristic line B, and further charging is continued. VBiOV2 is reached at point t7.

  When the assembled battery voltage VBi reaches VGU + δ1, which exceeds the upper limit voltage VBU2 = VGU by about 5%, the voltage discriminating unit 71 compares the voltage VBi with the upper limit voltage VGU and generates a discrimination output VGUg, as described above. The voltage holding unit 70 holds the voltage. The voltage holding unit 70 outputs the assembled battery holding voltage VBU2 and compares it with the assembled battery converted holding voltage VbU1 by the voltage discriminating unit 68. When VBU2> VbU1, the discriminating output bnU is generated, and the limiting calculating unit 44 When given, the limit command BnUG corresponding to VGU-δ1 is given to the command limiter VGL2, and the voltage limit control of the generator G similar to the control based on the unit cell voltage is performed.

The command limiter VGL1 to which the upper limit set voltage VGU set in the upper limit voltage setting 35 is added as a limit command acts as a voltage limit element for the generator when the voltage control of the generator is performed manually.

When the battery pack voltage VBi rises to VGU + δ2, which exceeds the upper limit voltage VGU by 10% or more, or when the lower limit set voltage VGL falls to VGL-γ, which has fallen by 10% or more, the voltage discrimination 71 detects this. The alarm signal VbAL2 is output to the monitoring controller 78. The monitoring control unit 78 displays and records the operating state of the assembled battery, and also issues an alarm. If the battery is abnormal, the monitoring control unit 78 turns off the assembled battery switch S1 and disconnects it from the power supply bus of the hybrid power source to protect the assembled battery. Or, stop the generator and stop charging to protect the battery pack.
[Discharge operation]
The discharge operation of the battery power supply 2 that drives the propulsion device 4 with power from only the battery power supply 2 will be described with reference to FIG.

  FIG. 4 shows, in a time series manner, changes in individual detection voltages of a plurality (n) of battery elements (single cells) b1 to bn constituting the assembled battery during the discharging operation.

  The cell voltage detector 63 in FIG. 1 sequentially scans and selects the cells b1 to bn in synchronization with the clock pulse CP of the clock pulse generator 60, and the voltage Vb1 of the cell b1 at time t1 in FIG. The voltage Vb2 of the cell b2 at time t2, the voltage Vb3 of the cell b3 at time t3,... the voltage Vbn-1 of the cell bn-1 at time tn-1, the voltage Vbn of the cell bn at time tn. Is detected. The detected single cell voltage Vbn is output to the lower limit determination unit 64L of the voltage determination unit 64. The lower limit discriminating unit 64L of the voltage discriminating unit 64 outputs the unit cell voltage Vbn as the discrimination output VbLn when Vbn ≦ VbL as compared with the lower limit setting voltage VbL each time.

  The determination output VbLn is held in the holding unit 65L of the voltage holding unit 65 as a unit cell lower limit voltage. The battery cell lower limit voltage VbLn held in the holding unit 65L is converted by the conversion unit 65Ld of the battery pack conversion unit 66 to a voltage equivalent to the battery voltage by multiplying the number of battery cells connected in series (n). A conversion lower limit voltage VbL1 (= VbLn × n) is obtained. The assembled battery conversion lower limit voltage VbL1 obtained by the assembled battery conversion unit 66 is added to the voltage determination unit 69.

  On the other hand, the assembled battery voltage VBi detected by the voltage detector 9 that detects the assembled battery voltage VBi is given to the lower limit voltage determination unit 71L of the voltage determination 71. When the voltage discriminating unit 71L detects the VBi that is equal to or lower than VGL by comparing the assembled battery voltage VBi with the assembled battery lower limit voltage VGL set in the assembled battery lower limit voltage setting device 36, the assembled battery voltage VBi is output as the discriminant output VGLg. This is given to the lower limit holding unit 70L of the voltage holding unit 70. The voltage holding unit 70L holds the discrimination output VGLg in synchronization with the clock pulse CP, and applies this to the voltage discrimination unit 69 as the assembled battery lower limit voltage VBL2.

  The voltage discriminating unit 69 compares the assembled battery conversion lower limit voltage VbL1 with the assembled battery lower limit voltage VBL2, selects the lower voltage, and outputs it as a speed limit command MnD (VbL1 or VBL2).

  Here, when the battery pack lower limit voltage VBL2 and the battery pack conversion lower limit voltage VbL1 obtained by multiplying the battery cell voltage by n are compared, the battery pack conversion lower limit voltage VbL1 is obtained by reducing a part of the battery cell voltage in the battery pack. Since it is the voltage converted into the assembled battery, the assembled battery converted lower limit voltage VbL1 is lower than the assembled battery lower limit voltage VBL2 which is the assembled battery voltage itself (VbL1 <VBL2).

  Therefore, in most cases, the voltage determination unit 69 selects the assembled battery conversion lower limit voltage VbL1 and gives it to the speed control unit 14 of the propulsion device 4 as the speed limit command MnD.

  Further, the assembled battery conversion setting lower limit voltage VbLM, which is obtained by multiplying the unit cell voltage setting lower limit voltage VbL by the lower limit conversion unit 66Ls and multiplying the number of unit cells by n, is given from the assembled battery conversion unit 66 to the speed control unit 14.

  Upon receiving the speed limit command MnD, the speed control unit 14 decreases the output of the power converter INV so that the assembled battery or single battery voltage does not fall below the assembled battery conversion setting lower limit voltage VbLM, thereby reducing the rotational speed of the propulsion motor M. Decelerate.

  In FIG. 4, the voltage Vbn of the unit cell bn passes between the time points t1 to t2 and the time point t2 to t3 of the T1 period when the voltage Vbn is higher than the unit cell setting lower limit voltage VbL. The voltage determination unit 64L of the voltage determination unit 64 outputs the determination output VbLn between the time t3 and the time t4 when the voltage Vb3 coincides with the unit cell set lower limit voltage VbL and Vbn ≧ VbL, and is held as 1 in the lower limit voltage holding unit 65L. The lower limit conversion unit 66L of the assembled battery conversion unit 66 converts it to a lower limit voltage VbL1 corresponding to the assembled battery voltage, and this is converted by the voltage determination unit 69 to the assembled battery lower limit voltage VBL2 held by the voltage holding unit 70L. Is discriminated. When the voltage determination unit 69 determines that VbL1 <VBL2, the speed limit command Mnd is generated, the speed limit control of the propulsion device 4 as described above is performed, and the voltage Vb3 of the cell b3 is set to the lower limit set voltage VbL. It is made not to fall below.

  Since the voltages Vbn-1 and Vbn of the single cells bn-1 and bn are larger than the lower limit set voltage VbL between the time points tn-1 and tn and between the time points t1 and t1 of the T1 cycle, the period is not changed. Also pass without control. Further, when the voltage Vb1 of the unit cell b1 equal to VbL is detected between the time points t1 and t2 of the T2 cycle, the voltage determination unit 64L outputs the unit cell voltage Vb1 as the determination output VbLn, so that the voltage holding unit 65L The hold is updated to hold 2. The battery pack conversion lower limit voltage VbL1 obtained by converting the hold voltage VbLn held in the voltage hold unit 65L into the battery pack voltage equivalent voltage by the battery pack conversion unit 66Ld is determined by the voltage determination unit 69, and the speed limit command MnD is transmitted to the speed control unit. 14 and the speed limit control of the propulsion device 4 is performed.

  Between the time points t2 and t3 of the T2 cycle, the voltage Vb2 of the unit cell b2 is higher than VbL, and thus this period passes without being controlled. When it is detected that the voltage Vb3 of the cell b3 has dropped to VbL-δ1 that is about 5% lower than the lower limit setting voltage VbL at the point t3, the voltage determination unit 64L determines this and determines the clock pulse stop signal St Is output to temporarily stop the operation of the clock pulse generator 60 and the single battery voltage detector 63 and hold and reset the voltage holding units 66L and 70L.

  At this time, the voltage Vb3 of the unit cell b3 is stored in the voltage holding unit 65L while the determination output VbLn of the voltage determination unit 64L is converted into the unit cell conversion lower limit voltage VbL1 by the unit cell conversion unit 66Ld, which is further converted into the voltage determination unit 70L. And the speed limit command MnD is generated and given to the speed control unit 14, and the assembled battery conversion lower limit voltage VbLM converted to the assembled battery voltage is given to the speed control unit 14.

  The speed control unit 14 reduces the rotational speed of the propulsion motor M so that the speed limit command MnD coincides with the lower limit set voltage VbLM, and the cell b3 voltage Vb3 is changed from VbL-δ1 to t4 in the cycle T2 as shown in FIG. It rises toward the time point and coincides with VbL at time point t4.

  The voltage discriminating unit 64L detects the coincidence, outputs the discriminating output VbLn, updates the holding of the voltage holding unit 65L to the holding 3, and then performs the same motor speed limit control as described above.

  Thus, if the cell voltage Vbn> the cell lower limit setting voltage VbL, the holding voltage is passed as it is. Therefore, the speed control unit 14 performs control to limit the rotation speed of the propulsion motor M so that the cell voltage Vbn is maintained at the holding voltage VbLn. Each time Vbn = VbL is detected, the holding voltage is updated and the rotational speed limit control of the propulsion motor M is performed so as to be maintained at Vbn = VbL by the speed limit command MnD, and the unit cell voltage Vbn is lower than the lower limit set voltage VbL. When VbL-δ1 is reduced by about 5%, the speed of the electric motor M is reduced to control the speed limit command MnD so that it matches the assembled battery conversion lower limit voltage VbLM.

  At the point t3 of the T4 cycle, the voltage Vb3 of the cell b3 drops below the voltage VBL-δ2 that is about 10% lower than the cell lower limit voltage VbL. At this time, the voltage discriminating unit 64L detects this, outputs an alarm signal VbAL1, and gives it to the monitoring control unit 78.

  The supervisory control unit 78 issues an alarm by the alarm signal VbAL1, and turns off the switch S1 to stop the power supply from the battery power source 2 to the propulsion device 4, thereby stopping the discharge of the battery of the battery power source 2 or propulsion. The unit cell b3 is protected from overdischarge by taking measures such as stopping the electric motor M.

  In addition, every time the cell voltage Vbn reaches the lower limit installation voltage VbL, the monitoring controller 78 converts the data held in the voltage holding unit 65L by the determination output VbLn of the voltage determination unit 64L together with the data Sn indicating the cell number. Record and display together with data indicating the operating status such as the voltage lower limit voltage arrival time, etc., to provide monitoring of the operating status of the operator.

  By controlling the discharge operation of the battery power supply 2 in this way, the voltage due to overdischarge due to the discharge operation is applied to each battery element (unit cell) of the battery power source configured by connecting a plurality of battery elements (unit cells) in series and parallel. By controlling the power supplied to the load such as the electric motor M so that the voltage of the unit cell does not drop below the set lower limit voltage when an abnormal drop occurs, the excessive voltage drop of each battery element is prevented. Thus, the deterioration of characteristics can be suppressed, so that the life of the entire battery can be extended.

  FIG. 5 shows a second embodiment of the present invention. In this embodiment, the capacity of the battery power source 2 is increased by connecting a plurality (N) of the assembled batteries constituting the battery power source in the first embodiment of the present invention shown in FIG. 1 in parallel.

The battery power source 2 of the hybrid power source 1 in the second embodiment is configured by connecting a plurality (N) of assembled batteries B1 to BN in parallel.

  Since the voltage VBi of each of the assembled batteries B1 to BN connected in parallel has the same value, the operating state of each assembled battery cannot be monitored by voltage.

  Therefore, as shown in Patent Document 2, protection of individual battery packs connected in parallel is performed based on battery pack current detected for each battery pack. For this reason, also in the second embodiment, the battery pack current detectors ID1 to IDN are connected in series to the battery packs B1 to BN to detect the currents IB1 to IBN of the battery packs.

  The other configurations of the power generation device 3, the propulsion device 4, the speed control unit 14, the charge / discharge control unit 5 and the like of the second embodiment are the same as those of the first embodiment, and the internal configuration of the charge / discharge control unit 5 is omitted. Shown in one block.

  In the second embodiment, when a plurality of assembled batteries B1 to BN connected in parallel with the battery power source 2 are charged together in the constant current charging mode or the constant power charging mode, the battery voltage VBi detected by the voltage detector 9 is the upper limit. When the set voltage VGU is reached, the charge / discharge control unit 5 performs voltage limit control of the generator G so that the battery voltage VBi does not exceed the assembled battery upper limit set voltage VGU set in the upper limit voltage setter 35. Thereby, the overcharge of an assembled battery is suppressed.

  Further, when the assembled battery voltage VBi significantly exceeds the upper limit setting voltage VGU, for example, 10% or more, the switch S1 is turned off and the assembled battery is disconnected from the power generator 3 or the power generator 3 is stopped. Then, charging of the battery of the battery power source 2 is stopped, and the assembled battery is protected from overcharging.

  During the charging operation, the unit cell voltage detectors 63-1 to 63-n provided in each of the assembled batteries B1 to BN detect the voltage Vbn of each unit cell, and any one of the unit cell voltages Vbn is the upper limit set voltage VbU. Is reached, the voltage limit control of the generator G is performed so that the unit cell voltage Vbn does not exceed the upper limit set voltage VbU. Thereby, the overcharge of the cell which comprises an assembled battery is suppressed.

  In addition, when the unit cell voltage Vbn greatly exceeds the upper limit set voltage VbU, for example, 10% or more, the switches S21 to S2N connected to the unit cell to which the unit cell belongs are turned off, and the corresponding unit cell is turned off. Disconnect from the buses P and N of the hybrid power supply 1 to protect the unit cell from overcharging.

  In the discharge operation of the battery power source 2, that is, in the state where the battery power source 2 is operated by supplying a drive current to the propulsion device 4, the voltage VBi of the battery power source 2 becomes the lower limit set voltage VGL set in the assembled battery lower limit voltage setting unit 36. When the voltage reaches the limit, the battery pack voltage VBi is controlled to limit the power supplied to the propulsion device 4 via the speed controller 14 so that the assembled battery voltage VBi does not drop below the lower limit set voltage VGL, and the electric motor M is decelerated to reduce the rotational speed. Reduce the current. Thereby, the overdischarge of assembled battery B1-BN which comprises the battery power supply 2 is suppressed.

  Further, when the voltage Vbi of any single cell constituting the assembled battery reaches the lower limit set voltage VbL set in the single cell lower limit voltage setting unit 62, the single cell voltage Vbi is not lowered below the lower limit set voltage VbL. In addition, limit control of the power supplied to the propulsion device 4 is performed via the speed control unit 14 to decelerate the motor rotation speed. Thereby, the overdischarge of the cells b1 to bNn constituting the battery power source 2 is suppressed.

  In addition, when the unit cell voltage Vbi significantly decreases the unit cell lower limit setting voltage VbL, for example, by 10% or less, the switches S21 to S2N of the unit cell to which the unit cell belongs are turned off, and the corresponding unit cell is hybridized. Protection from the abnormal voltage drop due to disconnection from the buses P and N of the power supply 1 and overdischarge of the unit cell.

  1: Hybrid power source, 2: Battery power source, B, B1-BN: Battery pack, b1-bNn: Battery element (single cell), 3: Normal power source (power generation device), 4: Propulsion device, 5: Charge / discharge control unit , 14: speed control unit, 78: monitoring control unit, 80: battery voltage monitoring control unit.

Claims (3)

Usually composed of a battery power source configured by connecting a plurality of rechargeable battery elements (single cells) connected in series to each other in parallel, and a power generator for charging the battery of this battery power source In an electric drive system in which a load of an electric motor is driven by a hybrid power source including a power source,
Battery voltage detecting means for detecting the voltage (unit cell voltage) of each battery element (unit cell) and the voltage of the assembled battery (assembled battery voltage) constituting the battery power source when charging and discharging the battery power source;
Voltage determination means for comparing the cell voltage and the assembled battery voltage detected by the battery voltage detection means with the cell upper limit set voltage or the cell lower limit set voltage and the battery pack upper limit set voltage or the battery pack lower limit set voltage, respectively.
An assembled battery voltage converting means for obtaining an assembled battery converted voltage by multiplying the unit cell voltage detected by the battery voltage detecting means by the number of cells connected in series in the battery power supply;
During charging of the battery power supply, when said single cell voltage or the battery pack voltage exceeds the single battery upper limit set voltage or the battery pack upper limit set voltage, the on thus assembled battery referred voltage obtained as the assembled battery voltage converting means either higher voltage the unit cell voltage and the voltage of the battery module both or either one of voltages above unit cell upper limit set voltage or battery pack limit based on the of the detected voltage of the battery module in the battery voltage detection means Means for limiting a charging voltage supplied from the normal power supply so as not to exceed a set voltage;
During discharge of the battery power supply, when said single cell voltage or the battery pack voltage exceeds the unit cell lower limit setting voltage or the battery pack lower limit setting voltage, the on thus assembled battery referred voltage obtained as the assembled battery voltage converting means comparing the assembled battery voltage detected by the battery voltage detection means, whichever is lower the unit cell voltage and the battery pack voltage based on the voltage of both or one of voltage the unit cell lower limit setting voltage Or means for limiting the power supplied from the battery power source to the load so as not to exceed the battery pack lower limit setting voltage,
A charge / discharge control device for a battery power source comprising: The charge / discharge control device for a battery power source according to claim 1, wherein when the battery pack converted voltage and / or battery battery voltage exceeds the upper limit set voltage or the lower limit set voltage , the set having the battery. A battery power supply charge / discharge control device that protects the assembled battery by disconnecting the assembled battery from the power supply circuit. In the charge and discharge control device for a battery power source according to claim 1 or 2, the single cells and a battery both cell number and cell voltage constituting the battery power source, and upon reaching the date of the upper limit set voltage or lower limit set voltage A battery power supply charge / discharge control device characterized by recording and displaying.

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