JP3529623B2 - Apparatus and method for detecting remaining capacity of series-parallel switching storage power supply - Google Patents

Abstract

PROBLEM TO BE SOLVED: To correctly detect the residual energy which can be extracted from a series-parallel switching storage power supply, even if the connection is switched from a parallel to a series one, when the voltage drops. SOLUTION: As a series-parallel switching storage power supply 101, battery units are composed of a pair of storage batteries C11, C12 and C21, C22, each of which has its voltage dropped by a large amount as energy is taken out. The battery units are serially connected in a plurality of stages. As the voltage drops, the battery units are switched from a parallel connection to a series connection in stages, one step at a time, by means of switching means S11-S13, S21-S23. This system, being provided with a voltage detector for detecting the voltage, switching signal detectors S14, S24 for detecting switching signals for respective battery units, an operator 104 for making an operation, based on the detected voltage and switching signals, finds the residual energy of the series-parallel switching storage power supply 101 from the detected voltage in accordance with the switching conditions of the battery units.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses a storage battery whose voltage drops greatly as energy is taken out.
A pair of rechargeable batteries constitutes a battery unit having switching means for parallel connection and series connection, the battery units are connected in series in a plurality of stages, and the battery units in a plurality of stages are connected in parallel one by one due to a voltage drop. The present invention relates to a remaining amount detecting device and a remaining amount detecting method for a series-parallel switching storage power source that is switched from connection to series connection.

[0002]

2. Description of the Related Art ECS using an electric double layer capacitor
Electric power storage devices based on (Energy Capacitor System) are attracting attention as power supply devices for electric vehicles and large-scale electric power storage devices. The electric double layer capacitor, like a chemical battery such as a lead battery or a nickel-cadmium battery, which takes a long time to be charged, is a physical charge like other capacitors, and thus can be rapidly charged. In addition, the electric double layer capacitor battery has a great advantage over the chemical battery that it can store a large amount of energy. However, a chemical battery is a constant voltage device, and even if power is supplied to a load in the normal operating range, the terminal voltage shows a constant constant voltage characteristic regardless of the amount of energy stored in the battery. Te, the battery of the electric double layer capacitor, when by increasing the storage amount of the power to attempt to effectively utilize it, has the characteristic that the terminal voltage varies greatly based on the relationship Q = CV ^2/2. That is, the terminal voltage of the electric double layer capacitor greatly changes from the full charge voltage to zero as the stored energy is discharged,
In order to supply a stable rated voltage to the load, it is necessary to adjust the output voltage significantly with ECS.

The ECS has already been used as a power energy storage system consisting of a capacitor, a parallel monitor and a current pump in various documents (eg, electronic technology, 1994-12, p1 to p1).
3, Electronics B, Vol. 115, No. 5, 1995, p504-6
10 etc.). Where the parallel monitor is
This is a device in which a plurality of capacitors are connected between the terminals of each capacitor of a capacitor bank connected in series and parallel, and the charging current is bypassed when the charging voltage of the capacitor bank exceeds the set value of the parallel monitor.

Since the capacitor bank having the parallel monitor described above bypasses the charging current and keeps it constant so that the charging voltage of the capacitor bank does not rise above a set value when charging, all capacitors in the capacitor bank are , Evenly charged up to the set voltage, the storage capacity of the capacitor can be exerted almost 100%. Therefore, the parallel monitor performs equalization of maximum voltage, prevention of reverse current, detection and control of end-of-charge voltage, etc. even when there are variations in the characteristics of capacitors and the magnitude of residual charge, so that the full withstand voltage can be used. As a thing
It plays an extremely important role and is an indispensable device as a means of effectively utilizing energy density.

FIG. 10 is a diagram showing a standard configuration example of an ECS, and FIG. 11 is a diagram showing a step-up / step-down operation region of an ECS current pump. In the power storage device by ECS, FIG.
From the electric double layer capacitor that stored the power as shown in
Electric power is taken out by a switching type DC / DC converter called a current pump, converted into a constant voltage, and supplied to a load. The current pump used at this time may be a step-down chopper, a step-up chopper, or other DC / DC converter, but high efficiency is an essential condition, so the type using a transformer is not advantageous.

[0006] Now, in an ECS power storage device, if it is attempted to utilize the voltage of the capacitor up to ¼ of the voltage when fully charged, the power is 15/16 = 93.75%.
Will be used. In order to realize it, the boost converter selects the output voltage V _O equal to the voltage V _O ^* 4 at the time of full charge, boosts it by the converter as shown in up of FIG. 11, and the output is always V _O ^* 4. Control it.
At this time, the operating range of the boost converter is boosting from 1 to 4 times. In the step-down converter, the output voltage V
_O is selected to be equal to 1/4 of the voltage V _O ^* 1 at full charge, and as shown in down of FIG. 11, the converter steps down to 1/4 at the start of discharge, and the step-down ratio is reduced with discharge to output. Is controlled to always be V _O ^* 1, the rated voltage can be supplied until the voltage of the capacitor becomes the first ¼. Therefore, the operating range of the buck converter at this time is 1 /
The voltage is reduced from 4 to 1.

As described above, in the ECS, the voltage range of the capacitor used is widened to increase the amount of electric power that can be stored. Therefore, it is an essential phenomenon that the terminal voltage of the capacitor greatly changes. However, depending on the application, it may be inconvenient for the ECS to significantly change the voltage as compared with the conventional secondary battery.

Therefore, as a power supply device using a battery having a large voltage fluctuation in which the voltage gradually decreases as the energy is taken out from the fully charged state, for example, a power supply device using an electric double layer capacitor, a series-parallel battery is used to make the voltage on the power supply side constant. A configuration for switching is already proposed (Japanese Patent Laid-Open No. 8-16
8182). This is a voltage or current supplied to a load by a switching means using a plurality of batteries with large voltage fluctuations, switching means for switching the batteries from parallel connection to series, and batteries connected in parallel and series by the switching means as power sources. And switching means for switching the batteries from parallel connection to series connection as the voltage drops. The switching means includes, for example, first to third switching switches using semiconductor elements, and a series circuit of the battery and the second switching switch and a series circuit of the third switching switch and the battery are connected in parallel. The first changeover switch is connected between the series connection points of the respective series circuits, and the second changeover switch and the third changeover switch are operated complementarily to the first changeover switch.

According to the conventional device proposed above, the step-down ratio and the step-up ratio can be reduced regardless of whether the step-down converter or the step-up converter is used as the control means. It is possible to improve efficiency. Furthermore, since the degree of freedom in selecting the semiconductor to be used and the degree of freedom in design can be increased, the economical efficiency of the device can be improved.

[0010]

However, a battery with a large voltage fluctuation, for example, an electric double layer capacitor, in which the voltage gradually decreases as energy is taken out from the fully charged state, and parallel connection is switched to series connection as the voltage decreases, is used. As a result, in the above power supply device in which the fluctuation of the voltage is reduced and the power supply voltage is stabilized, there is a problem that the remaining amount of energy stored in the power supply cannot be displayed correctly. That is, in the electric double layer capacitor battery, the terminal voltage is usually detected using a voltmeter and displayed as the remaining amount. Therefore, when the energy is taken out in parallel connection from the fully charged state and when the voltage is lowered and the connection is switched from parallel connection to series connection, the latter has a smaller remaining amount of energy even if the voltage is almost the same. However, the amount of remaining energy detected by the voltmeter is the same.

[0011]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and correctly detects the remaining amount of energy that can be extracted from a series-parallel switching accumulator even when switching from parallel connection to series connection when the voltage drops. It enables you to do it.

To this end, the present invention uses a storage battery composed of a capacitor in which the remaining amount of energy is proportional to the square of the voltage and the voltage drops as energy is taken out, and a pair of storage batteries is used to switch between parallel connection and series connection. this switching connected in series the battery unit in a plurality of stages constitute a battery unit, a battery unit of the plurality of stages from stage connected in parallel by one step by reduction of the output voltage to a series connection with
A device for detecting the remaining amount of a series-parallel switching accumulator power supply configured to suppress the fluctuation range of the output voltage by means of: voltage detecting means for detecting the output voltage of the series-parallel switching accumulator power supply; Switching detection means for detecting each switching signal of the unit, and voltage detected by the voltage detection means
And the capacitance of the series-parallel switching storage power source and the plurality of stages of batteries
Calculating means for obtaining the remaining amount of energy of the series-parallel switching storage power source based on a switching signal of the unit , wherein the calculating means is equivalent capacitance of the battery units of a plurality of stages according to the switching signal. The additional coefficient for converting into a voltage corresponding to is changed and the additional coefficient is calculated with the voltage detected by the voltage detecting means to obtain the remaining amount of energy based on the voltage and the equivalent capacitance. It is what

Further, a voltage detecting means for detecting a preselected one voltage of the storage battery from among the battery units of the plurality of stages, the voltage detected by said voltage detecting means
The capacitance of the series-parallel switching storage power source and the battery unit of the above-mentioned multiple stages.
And a calculation means for obtaining the remaining amount of energy of the series-parallel switching storage power source based on the switching signal of the power supply.

Further, using a storage battery composed of a capacitor whose remaining amount of energy is proportional to the square of the voltage and voltage drops as energy is taken out, a battery unit having a pair of storage batteries and having switching means for parallel connection and series connection is provided. connected in series the battery unit in a plurality of stages constituting the output by switching to a series connection of the battery units of the plurality of stages from stage connected in parallel by one step by reduction of the output voltage
A serial-parallel switching換蓄remaining power detecting method which is to suppress the fluctuation range of the power voltage, the output of the serial-parallel switching換蓄power
Power voltage or the voltage of the storage battery of a preselected battery unit is detected, and the detected voltage and the series-parallel switching storage power source
Based on the electrostatic capacity of the
It is characterized in that determining the remaining energy level of the Hazuki the serial-parallel switching換蓄power.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a diagram for explaining an embodiment of a remaining amount detecting device and a remaining amount detecting method for a series-parallel switching storage power source according to the present invention, 101 is a series-parallel switching storage power circuit, 102 is an output adjusting circuit, 103 is a load, 104 is a coefficient addition arithmetic circuit, 105 is a remaining amount indicator, C11, C1
2, C21, C22 are storage batteries, S11-S13, S21
S23 are serial / parallel changeover switches, and S14 and S24 are auxiliary switches.

In FIG. 1, a serial / parallel switching power storage circuit 10 is shown.
Reference numeral 1 denotes a storage battery C composed of, for example, one or a plurality of electric double layer capacitors connected in series and parallel as necessary.
11, C12, C21, C22, and serial / parallel changeover switches S11 to S13 and S21 to S23 for switching these in serial / parallel according to the voltage drop due to discharge. S13 for the serial / parallel selector switches S11 and S12, and similarly S23 for the serial / parallel selector switches S21 and S22.
Respectively operate complementarily, and when the serial / parallel changeover switches S11, S12, S21, S22 are turned on as shown in the figure, the serial / parallel changeover switches S13, S23 are turned off and the storage batteries C11 and C12, C21 and C22 are turned on. Connect in parallel, and conversely, serial / parallel changeover switches S11, S12, S21,
S22 is turned off, and serial / parallel changeover switches S13, S23
By turning on the storage batteries C11, C12, C2
1 and C22 are connected in series. The auxiliary switch 14 is interlocked with the operation of the serial / parallel changeover switches S11 to S13, and the auxiliary switch 24 is interlocked with the operation of the serial / parallel changeover switches S21 to S23.
.About.S13 and S21 to S23 are used to detect the respective operating states, that is, the switching signals.

In the series-parallel switching storage power supply circuit 101, the pair of storage batteries C11 and C12 and C21 and C are fully charged.
When the voltage is lowered by connecting 22 in parallel and extracting energy, for example, the following switching control is performed. First, when the voltage drops to ⅔ of full charge, the first pair of storage batteries C11 and C12 are switched to series connection.
By this switching, the voltage of the series-parallel switching storage power supply circuit 101 becomes the voltage at the time of full charge again. When the voltage drops from here to 2/3 of the fully charged voltage, the second pair of storage batteries C21 and C22 are switched to series connection. As described above, the series-parallel switching storage power supply circuit 101 includes the pair of storage batteries C1.
1 and C12, C21 and C22 constitute a battery unit having switching means S11 to S13 and S21 to S23 for parallel connection and series connection, the battery units are connected in series in a plurality of stages, and a plurality of stages are formed due to a decrease in voltage. By switching the battery unit from parallel connection to serial connection step by step, even if a storage battery whose voltage drops significantly as energy is taken out, a large amount of energy is stored in the storage battery while reducing the voltage fluctuation. It is designed so that it can be taken out.

The output adjustment circuit 102 stabilizes the voltage of the series-parallel switching storage power supply circuit 101 that fluctuates as energy is extracted as described above and supplies it to the load 103 by using a step-up converter or step-down converter. It is an adjustment circuit. By detecting the voltage of the series-parallel switching power storage circuit 101, that is, the voltage that changes in accordance with the change in the remaining amount of stored energy, and by detecting the states of the auxiliary switches 14 and 24 as the battery unit switching signal. The coefficient addition calculation circuit 104 changes the addition coefficient based on the detected switching signal, calculates the detected voltage and the additional coefficient, and obtains the remaining energy of the series-parallel switching power storage circuit 101. Generally, the energy stored in a capacitor, that is, the remaining amount of energy is

[0019]

[Number 1] ^{_{C 0 V 0 2/2 ≒}} C 0n V n 2/2 C 0 (K n V n) 2/2 = C 0 V 0 2/2 C 0, V 0: reference made original straight Equivalent capacitance of parallel circuit and voltage C _0n , V _n : Equivalent capacitance after serial-parallel switching and voltage K _n : K _n V _n = V ₀ = calculated by a coefficient. For example, in the series-parallel switching storage power supply circuit 101 shown in FIG. 1, when the voltage drops from the full-charge voltage to 2/3, the storage batteries C11 and C12 are connected in series, and the voltage again rises to 2/3 of the full-charge voltage. When the battery voltage decreases, the storage batteries C21 and C22 are connected in series, and two-stage control is performed so as to form a series circuit of the storage batteries C11, C12, C21, C22. In this case, in the coefficient addition arithmetic circuit 104, when K _{n is set} to 1 at the time of full charge and the control of the first stage is performed, that is, when the auxiliary switch S14 is turned on, K _n is changed to 0.667 and the second When the step control is performed and the auxiliary switch S24 is turned on, K _{n is set} to 0.
Set to 5. When a calculation using such an additional coefficient is performed and the output of the coefficient addition calculation circuit 104 is displayed as the remaining amount by the remaining amount indicator 105, even if the parallel connection is switched to the series connection and the same voltage is detected, Remaining amount indicator 105
Then, when the battery is fully charged, the remaining amount of 100% is displayed, and when the control in the first stage is performed, it becomes 0.667 times the detected voltage,
The remaining amount of energy is 44%.

FIG. 2 is a diagram for explaining another embodiment of the remaining amount detecting apparatus and method of the serial / parallel switching storage power source according to the present invention, and FIG. 3 is the remaining amount of the serial / parallel switching storage power source according to the present invention. It is a figure for explaining other embodiment of a detecting device and a method. In the figure, 107 is a squaring circuit, 111 is a central controller, and 112 is an interface circuit.

In FIG. 2, a squaring circuit 107 squares the output of the additional coefficient computing circuit 104. By using the signal obtained by this calculation for the remaining amount display of the remaining amount indicator 105, the remaining amount of energy can be displayed in a straight line, that is, a scale proportional to the remaining amount.

In FIG. 3, the central control unit 111 performs the calculation by the additional coefficient calculation circuit 104 shown in FIG. 1 and the calculation by the square circuit 107 shown in FIG. 2, and the interface circuit 112 is the serial / parallel switching storage power source. Circuit 101
The voltage detected in step S14 and the serial / parallel switching signals detected by the auxiliary switches S14 and S24 are transferred to the central control device 111, and the residual amount signal calculated by the central control device 111 based on these signals is transferred from the central control device 111. Remaining amount indicator 10
5 is to be sent.

The serial / parallel switching power storage circuit will be described in more detail with a more specific configuration. FIG. 4 is a diagram showing a configuration example of a series-parallel switching power storage circuit in which battery units are serially connected in n stages,
FIG. 5 is a diagram for explaining the operation range. 1 in the figure
n is a serial / parallel switching capacitor unit, C11 to Cn2 are capacitor banks, S11 to Sn3 are changeover switches, and V
_O indicates the output voltage.

In FIG. 4, the series-parallel switching capacitor units 1 to n are the battery units described above which are composed of a pair of capacitor banks and a switching switch for switching between parallel connection and series connection. The capacitors are connected in cascade to form a capacitor power storage device for a series-parallel switching power storage circuit, and output voltage V _O is taken out. The capacitor banks C11 to Cn2 are formed by connecting a plurality of electric double layer capacitors having, for example, parallel monitors in series and parallel.
The parallel monitor has, for example, a semiconductor control element that bypasses the charging current as already known from the documents and applications introduced above, and when the charging voltage exceeds the set value by the control, the voltage of the set value is set. This is a device that bypasses the charging current while keeping the current at the same time, and turns on to short-circuit the electric double layer capacitor when the electric double layer capacitor connected in parallel fails and becomes in the abnormal charging state. The semiconductor rectifying device is connected in reverse polarity to the electric double layer capacitor in parallel, the semiconductor control device is connected in parallel to the electric double layer capacitor so as to bypass the charging current, and the monitor control circuit controls the semiconductor control device.

In the series-parallel switching storage power supply circuit configured as described above, first, when each of the capacitor banks C11 to Cn2 having the same rated voltage and capacity is fully charged, FIG.
As shown in FIG.
Is the first changeover switch S11, S21, ..., Sn
1, 2nd changeover switch S12, S22, ..., Sn2
Is on, the third changeover switch S13, S23, ..., S
n3 is off. That is, all the serial / parallel switching capacitor units 1 to n are connected in parallel.

Next, each capacitor bank C1 is discharged.
When the charging voltage of 1 to Cn2 is reduced and the output voltage V _O is reduced to at least one capacitor bank C11 to Cn2, only the first series-parallel switching capacitor unit 1 is provided as shown in FIG. 4B. Is the first changeover switch S1
The first and second changeover switches S12 are turned off and the third changeover switch S13 is turned on. As a result, only the first series-parallel switching capacitor unit 1 has the capacitor bank C.
This is a circuit in which 11 and C12 are connected in series, and the charging voltage of the capacitor bank C11 increases as a whole.

Further, by discharging, each capacitor bank C
The charging voltage of 11 to Cn2 decreases and the output voltage V _O decreases at least in parallel connected capacitor banks C21 to C21.
When the voltage of one Cn2 is reached, as shown in FIG. 4C, the second series-parallel switching capacitor unit 2 turns off the first switching switch S21 and the second switching switch S22, and the third switching switch. Turn on S23. As a result, the second series-parallel switching capacitor unit 2 following the first series-parallel switching capacitor unit 1 becomes a series connection circuit of the capacitor banks C21 and C22, and the charging voltage of the capacitor bank C21 increases as a whole. .

Similarly, each time the charging voltage of each of the capacitor banks C11 to Cn2 drops due to discharging, and the output voltage V _O drops by at least one capacitor bank in parallel connection, the capacitor banks are paralleled. The number of series-parallel switching capacitor units that switch from connection to series connection will be gradually increased. FIG. 5 shows how the voltage changes due to such multistage switching. As a result, the output voltage V _O fluctuates within the range of V _{U to} V _L as shown in FIG.

Here, the upper limit value V _U of the fluctuating voltage is V _U = V as a series connection voltage from the full charge voltage V _CF of the capacitor banks C11 to Cn2 and the number n of stages of the serial / parallel switching capacitor units 1 to n. It can be determined by _CF × n. Further, the lower limit value V _L of the fluctuating voltage is such that only the first series-parallel switching capacitor unit 1 has the capacitor bank C1.
Since the output voltage of the circuit in which 1 and C12 are connected in series changes from V _L to V _U , V _L = V _U −V _U / (n +
It can be obtained in 1). That is, the fluctuation range (V _U −V _L ) of the output voltage V _O can be suppressed to 1 / (n + 1). For example, if the number of stages n is 4, the fluctuation range is 20%.

FIG. 6 is a diagram showing a configuration example of a four-stage switching circuit of a series-parallel switching storage power supply circuit, and FIG. 7 is a diagram for explaining an operation comparison example with a conventional capacitor power supply device. As a series-parallel switching power storage circuit, for example, assuming that the number of stages n of the series-parallel switching capacitor unit is 4 and the full charge voltage V _CF of each capacitor bank is 30 V as shown in FIG. The upper limit value V _U is 120 V,
The lower limit value V _L of the fluctuating voltage is 96 V, which is lower by a voltage corresponding to 1/5 of the lower limit value V _L. Therefore, in the conventional device,
Range of 120V and 60V which is 1/2 of that, that is, 50%
However, in the present invention, the fluctuation range between 120 V and 96 V, that is, 20% can be suppressed. Actually, in the series-parallel switching of the first series-parallel switching capacitor unit 1, there is a fluctuation of 24V, but since the second series-parallel switching capacitor unit 2 and thereafter each capacitor bank are discharged, As shown in FIG. 7, the fluctuation range gradually becomes smaller. In FIG. 7, 0 is a device without serial / parallel switching, 1 is a device for performing conventional serial / parallel switching, and 4 is a device for performing four-stage switching of a serial / parallel switching capacitor unit. There is.

Further, as shown in FIG. 6, when the comparators A1 to A4 are connected to the respective serial / parallel switching capacitor units to detect the switching voltage, each comparator A is connected.
The setting of the switching voltage of 1 to A4 is, for example, 2 in the first stage.
4.2V, 2nd stage 21.3V, 3rd stage 19.5
V, and the third stage is 13.2V. Thus, even if each capacitor bank is evenly charged to full charge, the charging state of the capacitor banks in each stage becomes uneven as the battery is discharged. Serial / parallel switching may be performed. That is, each stage may be reversibly operated by charging and discharging. When performing reversible charging, if there is a voltage difference between the capacitor banks when switching from series to parallel, a large short circuit current will flow based on the voltage difference. Therefore, in order to avoid such a large current transiently flowing, a current limiting circuit as used in a constant voltage power source is connected to all switches using FETs. This is composed of a simple circuit using a current detector and a transistor.

Next, a series-parallel switching control circuit for controlling the change-over switch of the series-parallel switching power storage circuit will be described. FIG. 8 is a diagram showing a configuration example of the serial / parallel switching control circuit, and FIG. 9 is a diagram showing another configuration example of the serial / parallel switching control circuit.
Reference numerals 2 and 27 are comparators, 12-1 to 12-n are AND gates, 13-1 to 13-n are switching controllers, 21 and 26 are subtraction circuits, V _REF is a reference voltage, V _O is an output voltage, and V _O is an output voltage. _Cn indicates the capacitor bank voltage.

In the above embodiment, the switching voltage is detected by the comparator for each capacitor unit in accordance with the voltage drop due to the discharge, and the capacitor banks are connected and switched in series, but the output voltage V _O is detected. It is also possible to judge the switching voltage. FIG. 8 shows an example thereof, and in this case, the output voltage V
_O is compared with the reference voltage V _REF to sequentially switch the capacitor banks from parallel to series. That is, in the circuit shown in FIG. 8, first, the reference voltage V _{REF is set} to the value shown in FIG.
Is set to the lower limit value V _L of the fluctuating voltage, and in the comparator 11, when the output voltage V _O becomes smaller than the reference voltage V _REF , that is, the lower limit value V _L , a switching signal (for example, a signal of logic “1”). Is output. The AND gate 12-1 and the switching controller 13-1 constitute a circuit that controls switching of the capacitor unit 1 in the first stage, and the AND gate 12-2 and the switching controller 13-2 in the second stage. Capacitor unit 2
The AND gate 12-3 and the switching controller 13-3 are circuits for controlling the switching of the third-stage capacitor unit 3 ... And gate 1
The 2-n and the switching controller 13-n respectively configure circuits that control switching of the capacitor unit n at the n-th stage. And the AND gates 12-1 to 12-n are
Switching control signal of the condenser unit of the previous stage and the comparator 11
Is used as an input signal, and the output signal becomes logic "1" on the condition that the preceding capacitor unit is switched to the series connection and the output voltage is lower than the reference voltage, and the switching control of that capacitor unit is performed. Operate the vessel. The switching controllers 13-1 to 13-n operate according to the output signal when the logical conditions of the AND gates 12-1 to 12-n are satisfied, and switch the connection of the capacitor bank of the capacitor unit from parallel to series.

In contrast to the above example using the lower limit value V _L of the fluctuating voltage as the switching voltage, the example shown in FIG.
The switching voltage is set to the upper limit value V _U of the fluctuating voltage. In this case, the subtraction circuit 21 in FIG.
Subtracts the output voltage V _O from the reference voltage V _REF , and the comparator 22 compares the subtracted value with the capacitor bank voltage V _Cn of the final stage capacitor unit. Here, the reference voltage V _REF is set to an upper limit value V _U , and the output voltage V _O is the capacitor bank voltage V of the final stage capacitor unit.
_When it becomes lower than _Cn , the switching signal is output from the comparator 22. That is, the capacitor bank voltage V _Cn of the final-stage capacitor unit is used as a representative value of the capacitor bank voltage of the capacitor units connected in parallel among the capacitor units.

In the example shown in FIG. 9B, the switching voltage is controlled so that the average value of the fluctuating voltage becomes constant. Therefore, in FIG. 9B, the subtraction circuit 26 subtracts the output voltage V _O from the reference voltage V _REF , and the comparator 27 subtracts 1 from the subtracted value and the capacitor bank voltage V _Cn of the final-stage capacitor unit. Compare with the value of / 2. The reference voltage V _REF is an intermediate value between the upper limit value V _U and the lower limit value V _L , that is, the average value V _{M of the} fluctuating voltage =
(V _U + V _L ) / 2. By doing so, when the output voltage V _O decreases from the average value V _M by V _Cn / 2 or more, the connection of the capacitor units is switched from parallel to series, so that the output voltage V _O immediately after that is V V conversely. _Cn / 2
growing.

By increasing the number of stages of the capacitor unit as described above, the fluctuation range of the output voltage is reduced, so that a power supply device having a voltage stability of ± 10% or less, which is equivalent to that of a battery, can be realized. Moreover, with high efficiency,
It can be realized without requiring a large choke coil or high-voltage / high-current / high-speed switch. Of course, similarly to the conventional device, a step-down chopper circuit or a step-up chopper circuit may be used to further stabilize the output voltage.

As is clear from the voltage characteristics of the series-parallel switching power storage circuits shown in FIGS. 5 and 7, the larger the number of battery units connected in series, the smaller the voltage fluctuation range.
There is the same voltage that is repeated every time energy is taken out and the battery units are switched to series connection step by step. The correct remaining amount of energy can be calculated by changing the coefficient for the same voltage depending on the number of stages of the battery units switched to series connection. When the configuration is such that the n-stage battery unit is switched as shown in FIG. 4, the additional coefficient K _nm in the state where the m-th (m <n) is switched to the series connection is calculated by using, for example, the following formula. Can be set.

[0038]

## EQU00002 ## K _nm = n / (n + m) Further, focusing on the individual storage batteries constituting the battery unit, each storage battery has a unique voltage corresponding to the remaining energy of the entire series-parallel switching storage power supply circuit. Have. That is, in the series-parallel switching storage power supply circuit shown in FIG. 4, the voltage of the capacitor banks C11 and C12 has only one value for each remaining energy of the series-parallel switching storage power supply circuit. Moreover, the voltage varies depending on the set value in which each stage of the battery unit is connected in series, and also varies between the capacitor banks C11 and C12 and the capacitor banks Cn1 and Cn2. Therefore, it is possible to select any one of them or detect the voltage with an arbitrary number of samples, and obtain the remaining amount of energy in the series-parallel switching power storage circuit from those voltages. In this case, the voltage of the selected capacitor bank and the coefficient selected based on the switching signal of each battery unit can be calculated,
It is also possible to uniquely determine the remaining amount of energy from the voltage of the selected capacitor bank using a correspondence table of the voltage of the selected capacitor bank and the remaining amount of energy, for example, LUT (look-up table). . Further, any one of the capacitor banks C11 and C12, any one of the capacitor banks Cn1 and Cn2, and further, any one of the intermediate capacitor banks can be switched and used according to the remaining amount of energy.

The present invention is not limited to the above embodiment, but various modifications can be made. For example, in the above embodiment, an example of displaying the remaining amount of detected energy is shown, but the signal of the remaining amount of detected energy is
It may be used as a control signal for charging control, load control, or the like according to the level, or as a notification signal for notifying that the remaining amount is below a predetermined level. Further, the output of the coefficient addition calculation circuit is further calculated by the squaring circuit in FIG. 2 to display the remaining amount, but a polygonal line approximation circuit may be used. Further, although the state of the auxiliary switch that works in conjunction with the serial / parallel changeover switch is detected as the changeover signal of each of the battery units of a plurality of stages, the signal controlling the serial / parallel changeover switch may be detected as the changeover signal, or the serial / parallel changeover switch may be detected. The changeover switch is not only a mechanical switch such as a relay but also a power MOS.
A semiconductor switch such as a FET or a thyristor may be used, and the auxiliary switch may use other means for detecting its operating state.

[0040]

As is apparent from the above description, according to the present invention, a storage battery whose voltage greatly decreases as energy is taken out is used, and a pair of storage batteries has switching means for parallel connection and series connection. In a series-parallel switching storage power source in which a battery unit is configured and the battery units are connected in series in a plurality of stages, and the battery units in a plurality of stages are stepwise switched from parallel connection to series connection due to a voltage drop, The voltage of the series-parallel switching storage power source is detected, the switching signals of the battery units of multiple stages are detected, and the calculation is performed based on these detected voltages and switching signals to obtain the remaining energy of the series-parallel switching storage power source. , Even if the output voltage repeatedly changes from a parallel connection to a series connection with a multi-stage battery unit step by step, the remaining energy of the series-parallel switching storage power source can be accurately measured. It can be out. Further, by simply detecting the voltage of one storage battery selected in advance from the plurality of stages of battery units, the remaining amount of energy of the series-parallel switching storage power source can be obtained based on each switching condition of the plurality of stages of battery units. As a result, it is possible to accurately detect the remaining amount of energy of the series-parallel switching storage power source.

[Brief description of drawings]

FIG. 1 is a diagram for explaining an embodiment of a remaining amount detecting device and a remaining amount detecting method for a series-parallel switching storage power source according to the present invention.

FIG. 2 is a diagram for explaining another embodiment of the remaining amount detecting apparatus and method for a series-parallel switching storage power source according to the present invention.

FIG. 3 is a diagram for explaining still another embodiment of the remaining amount detecting apparatus and method for a series-parallel switching storage power source according to the present invention.

FIG. 4 is a diagram showing a configuration example of a series-parallel switching power storage circuit in which battery units are connected in series in n stages.

FIG. 5 is a diagram for explaining an operation range.

FIG. 6 is a diagram showing a configuration example of a four-stage switching circuit of a series-parallel switching power storage circuit.

FIG. 7 is a diagram for explaining an operation comparison example with a conventional capacitor power supply device.

FIG. 8 is a diagram showing a configuration example of a serial / parallel switching control circuit.

FIG. 9 is a diagram showing another configuration example of the serial / parallel switching control circuit.

FIG. 10 is a diagram showing a standard configuration example of ECS.

FIG. 11 is a diagram showing a step-up / step-down operation region of an ECS current pump.

[Explanation of symbols]

101 ... Serial / parallel switching power storage circuit, 102 ... Output adjusting circuit, 103 ... Load, 104 ... Coefficient addition arithmetic circuit, 105
... remaining amount indicator, C11, C12, C21, C22 ... storage battery, S11-S13, S21-S23 ... serial / parallel changeover switch, S14, S24 ... auxiliary switch

─────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-140081 (JP, A) JP-A-9-298805 (JP, A) JP-A-6-261452 (JP, A) (58) Field (Int.Cl. ⁷ , DB name) H02J ^7/ 00-7/12 H02J ⁷ /34-7/36 G01R 31/36 H02J 1/00 304

Claims (4)

(57) [Claims] 1. A battery unit comprising a pair of storage batteries and switching means for switching between parallel connection and series connection, using a storage battery comprising a capacitor in which the remaining amount of energy is proportional to the square of the voltage and the voltage drops as energy is taken out. connected in series the battery unit in a plurality of stages constitute the output voltage by switching the series connection from the plurality of stages cell units stages connected in parallel by one step of the reduction of the output voltage
A remaining amount detection device for a series-parallel switching storage power supply configured to suppress a fluctuation range of pressure , wherein voltage detection means for detecting the output voltage of the series-parallel switching storage power supply, and each of the plurality of stages of battery units Switching detection means for detecting a switching signal, the voltage detected by the voltage detection means and the serial / parallel switching
Capacitance of the storage power source and switching signal of the above-mentioned battery units of multiple stages
And a calculating means for obtaining the remaining energy amount of the series-parallel switching storage power source based on the above-mentioned number . 2. The calculating means changes the additional coefficient for converting into a voltage corresponding to the equivalent electrostatic capacity of the battery units of the plurality of stages by the switching signal, and the additional coefficient is detected by the voltage detecting means. 2. The residual amount detecting device for a series-parallel switching storage power source according to claim 1, wherein the residual amount of the energy is calculated based on the voltage and the equivalent capacitance by calculating the voltage. 3. A battery unit having a means for switching between parallel connection and series connection with a pair of storage batteries, which uses a storage battery composed of a capacitor whose remaining amount of energy is proportional to the square of voltage and whose voltage drops as energy is taken out. connected in series the battery unit in a plurality of stages constitute the output voltage by switching the series connection from the plurality of stages cell units stages connected in parallel by one step of the reduction of the output voltage
A remaining amount detecting device for a series-parallel switching storage power source configured to suppress a fluctuation range of pressure , which is selected in advance from one of the plurality of stages of battery units.
Voltage detecting means for detecting the voltage of one storage battery, the voltage detected by the voltage detecting means and the serial / parallel switching
Capacitance of the storage power source and switching signal of the above-mentioned battery units of multiple stages
And a calculating means for obtaining the remaining energy amount of the series-parallel switching storage power source based on the above-mentioned number . 4. A battery unit having a pair of storage batteries and a switching means for switching between parallel connection and series connection, using a storage battery composed of a capacitor in which the remaining amount of energy is proportional to the square of the voltage and the voltage drops as the energy is taken out. connected in series the battery unit in a plurality of stages constitute the output voltage by switching the series connection from the plurality of stages cell units stages connected in parallel by one step of the reduction of the output voltage
A method for detecting a remaining amount of a series-parallel switching storage power source, which is configured to suppress a fluctuation range of pressure, wherein the output voltage of the series-parallel switching storage power source or a voltage of a storage battery of a preselected battery unit is detected, and the detection is performed. Voltage and capacitance of the series-parallel switching storage power source and the plurality of stages
The method for detecting the remaining amount of energy of the series-parallel switching storage power source, which is obtained based on the switching signal of the battery unit .