JP5364893B2 - Storage battery charge amount determination apparatus and method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a charging amount judging device/method of a storage battery, which calculate a pulsating rate against an average value (for DC) of the current flowing in the storage battery such as a secondary battery and continuously and easily judge a charging amount during an operation in a power storage AC/DC conversion device in a single phase power supply. <P>SOLUTION: A value for ripple and a value for DC are taken out from a current detection value detected by a charging/discharging current detection means 201 in an extracting means for ripple 202 and an average value calculation part 203. A rate of a value for ripple against a value for DC, namely, the pulsating rate is calculated by a divider 204, and is stored in a storage means 205. A pulsating rate-SOC database where a change of the pulsating rate against a change of SOC which is previously measured is recorded in addition to the pulsating rate calculated from the detected current is stored in the storage means 205. An SOC judging means 206 can judge the SOC by collating the pulsating rate detected by the charging/discharging current detection means 201 with the pulsating rate-SOC database. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a storage battery charge amount determination device and method, and more particularly, to a storage battery charge amount determination for determining a storage battery charge amount of a secondary battery or the like during operation in a single-phase power storage AC / DC converter in a single-phase power source. The present invention relates to an apparatus and a method.

  In the storage battery system, the life deterioration of the storage battery proceeds by repeating charging and discharging in the operation process. In the storage battery system, it is also a big problem to delay the deterioration of the storage battery. As a method for suppressing the life deterioration of the storage battery, there is a method of estimating the amount of charge (SOC: State of Charge) of the storage battery and controlling so as not to overcharge / discharge based on the SOC. In this case, the SOC of the storage battery is controlled. It is important to know exactly.

  Conventionally, the detection of the SOC of a storage battery includes, for example, a method based on the specific gravity of an electrolytic solution in a lead storage battery and a method based on a terminal voltage in an unloaded state of the storage battery, that is, an open circuit voltage (OCV).

  Also, as a method of obtaining the SOC during system operation, the charging current and discharging current of the storage battery are integrated every predetermined period to obtain the integrated charging amount and the integrated discharging amount, and these integrated charging amount and integrated discharging amount are charged and discharged. There is a method of calculating the SOC by adding or subtracting to the SOC immediately before the start.

Japanese Patent Application No. 2007-303596

  However, since the former is required to detect the OCV in a no-load state, there is a problem that the SOC cannot be detected while the system is operating. In the latter case, when calculating the accumulated charge amount and the accumulated discharge amount, the measurement error of the current detector is accumulated, so there is a problem that the error is likely to increase in the long-term SOC calculation process. .

  The present invention has been made in view of such problems, and an object of the present invention is to provide a current flowing through a storage battery such as a secondary battery in a power storage system (PCS) in a single-phase power supply. It is an object of the present invention to provide a storage battery charge amount determination apparatus and method for calculating a pulsation rate with respect to an average value (DC component) of the battery and determining the SOC continuously during operation, that is, during charging or discharging, and simply.

  In order to achieve such an object, the invention described in claim 1 is an SOC determination device that determines a charge amount (SOC) of a storage battery included in a single-phase power storage AC / DC converter, and flows into the storage battery. And a current detection means for detecting a current discharged from the storage battery, and a current value detected by the current detection means is separated into a ripple component and a DC component, and a pulsation rate which is a ratio to the DC component of the ripple is calculated. Pulsation rate calculating means for performing the above operation, and SOC determination means for determining the SOC of the storage battery based on the amount of change in the pulsation rate based on the pulsation rate at a predetermined SOC.

The invention according to claim 2 is an SOC determination device for determining a charge amount (SOC) of a storage battery included in the single-phase power storage AC / DC converter, and a current flowing into and discharged from the storage battery. current detecting means for detecting a pulsation rate calculating means for calculating a ripple factor is a ratio for the DC component of the ripple component with respect to the current value detected by said current detecting means, the pulsation ratio corresponding to the parameter representative of the state of the battery The pulsation rate-SOC correspondence data in which the pulsation rate-SOC correspondence data is associated with each other, the pulsation rate-SOC correspondence data read from the storage means corresponding to the latest parameter indicating the state of the storage battery, and the pulsation SOC determining means for comparing the rate and determining the SOC of the storage battery, and the parameter representing the state of the storage battery is to integrate the charging current and the discharging current. One of the SOC specified based on the calculated SOC, the SOC at which the rate of decrease in pulsation rate starts to change during discharge, the rate of decrease in pulsation rate at the time of SOC decrease, and the rate of pulsation at 100% SOC To do.

  According to a third aspect of the present invention, in the SOC determination device according to the first or second aspect, when the SOC determination means detects that the rate of change of the pulsation rate has changed significantly, it is determined that the discharge is at the end of discharge. It is characterized by doing.

  The invention according to claim 4 is an SOC determination device, a single-phase power storage AC / DC converter having a storage battery and a smoothing circuit not including a reactor on the DC side, and flowing into the storage battery and discharging from the storage battery Current detecting means for detecting a current to be generated; pulsation rate calculating means for calculating a pulsation rate that is a ratio of a DC value of a ripple with respect to a current value detected by the current detecting means; and the pulsation at a predetermined SOC SOC determining means for determining the SOC of the storage battery based on a change amount of the SOC with respect to a change amount of a predetermined pulsation rate according to the rate.

The invention according to claim 5 is an SOC determination device, a single-phase power storage AC / DC converter having a storage battery and a smoothing circuit not including a reactor on the DC side, and flowing into the storage battery and discharging from the storage battery Current detecting means for detecting the current to be detected, pulsation rate calculating means for calculating a pulsation rate that is a ratio of the DC value of the ripple with respect to the current value detected by the current detecting means, and a parameter representing the state of the storage battery depending pulsation rate and the SOC memory means pulsation rate -SOC corresponding data associated is stored, the ripple factor -SOC corresponding data read from said memory means corresponding to the parameter representative of the state of the most recent of said battery When, a SOC determination means for determining the SOC of the pulsation rate and the storage battery by matching the parameters representative of the state of the storage battery, the charging current and One of the SOC specified based on the SOC calculated by integrating the electric current, the pulsation rate reduction rate starting to change during discharge, the pulsation rate reduction rate when the SOC is reduced, and the pulsation rate when the SOC is 100% It is characterized by being.

  The invention according to claim 6 is an SOC determination device, comprising a storage battery and a single-phase power storage conversion device having a smoothing circuit not including a reactor on the DC side, wherein the plurality of single-phase power storage conversion devices are Single-phase power storage AC / DC converters connected in series, current detection means for selectively detecting the current flowing into each storage battery, and the ratio of the current value detected by the current detection means to the DC component of the ripple A pulsation rate calculating means for calculating a pulsation rate, and an SOC determination means for determining the SOC of the storage battery based on a change amount of the SOC with respect to a change amount of the predetermined pulsation rate according to the pulsation rate at a predetermined SOC. It is characterized by comprising.

The invention according to claim 7 is an SOC determination device, comprising a storage battery and a single-phase power storage conversion device having a smoothing circuit not including a reactor on the DC side, wherein the plurality of single-phase power storage conversion devices are Single-phase power storage AC / DC converters connected in series, current detection means for selectively detecting the current flowing into each storage battery, and the ratio of the current value detected by the current detection means to the DC component of the ripple Pulsation rate calculating means for calculating the pulsation rate, storage means for storing pulsation rate-SOC correspondence data in which the pulsation rate and SOC according to the parameter representing the state of the storage battery are related, and the latest storage battery wherein the ripple factor -SOC corresponding data read from the storage means, the storage battery by collating the calculated ripple factor by the pulsation ratio calculating means corresponding to the parameter representing the state And a SOC judging means for judging OC, parameters representative of the state of the battery is identified based on the SOC calculated by integrating the charge current and discharge current, decreasing rate of the pulsation ratio starts changing during discharge It is one of the pulsation rate when the SOC, the pulsation rate when the SOC is reduced, and the pulsation rate when the SOC is 100% .

  The invention according to claim 8 is the SOC determination device according to claim 4 or 7, wherein when the SOC determination means detects that the pulsation rate is equal to or less than a preset threshold value, the storage battery is discharged at the end of discharge. It is determined that it is.

  A ninth aspect of the present invention is the SOC determination device according to any one of the first, fourth, and sixth aspects, wherein the predetermined SOC is 100%.

  The invention according to claim 10 is an SOC determination method for determining the SOC of a storage battery included in a single-phase power storage AC / DC converter, and detects current flowing into the storage battery and discharged from the storage battery. A step, a pulsation rate calculating step for calculating a pulsation rate that is a ratio of the ripple relative to the DC component, and a current value detected by the current detection means, and a predetermined SOC And an SOC determination step for determining an SOC of the storage battery based on a change amount of the pulsation rate based on the pulsation rate.

The invention according to claim 11 is an SOC determination method for determining the SOC of a storage battery included in the single-phase power storage AC / DC converter, and detects current flowing into the storage battery and discharged from the storage battery. A step, a pulsation rate calculating step for dividing a current value detected by the current detection means into a ripple component and a DC component, and calculating a pulsation rate that is a ratio to the DC component of the ripple, and a parameter representing the state of the storage battery The pulsation rate-SOC correspondence data corresponding to the parameter representing the latest state of the storage battery, read from the storage means storing the pulsation rate-SOC correspondence data in which the pulsation rate according to the SOC and the SOC are stored, and by matching the ripple factor calculated by the pulsation ratio calculating means possess a SOC determination step of determining SOC of the battery, Pa indicating the state of said storage battery The meter is specified based on the SOC calculated by integrating the charging current and the discharging current. When the SOC starts to change the rate of decrease of the pulsation rate at the time of discharge, when the rate of decrease of the pulsation rate when the SOC decreases, and when the SOC is 100% The pulsation rate is any one of the following.

  A twelfth aspect of the present invention is the SOC determination method according to the tenth or eleventh aspect, wherein when the SOC determination step detects that the rate of change of the pulsation rate has changed significantly, it is determined that the discharge is at the end of discharge. It is characterized by doing.

  A thirteenth aspect of the present invention is the SOC determination method according to the tenth aspect, wherein the predetermined SOC is 100%.

  According to the present invention, in a PCS in a single-phase power supply, a pulsation rate with respect to an average value (DC component) of a current flowing through a storage battery such as a secondary battery is calculated, and the SOC is being operated, that is, continuously during charging or discharging. And it becomes possible to make a simple determination.

  It is known that the internal resistance of a storage battery changes when the charge amount of the storage battery changes. In the present invention, by using the internal resistance change measurement method based on the pulsation rate (see Patent Document 1), it is possible to determine the SOC continuously and easily during operation. In particular, the SOC can be determined more effectively by configuring the DC side smoothing circuit without a reactor and using only a capacitor.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1)
FIG. 1A shows a main circuit configuration of a single-phase power storage PCS having a reactor as a smoothing circuit, and FIG. 1B shows a configuration of the SOC determination device according to Embodiment 1 of the present invention.

  Single-phase AC power supply 101 supplies AC power to PCS 102 via reactor L, and converts AC power into DC power by performing single-phase full-wave rectification in PCS 102. A storage battery 103 having an electromotive force Ei and an internal resistance ri is connected to the DC side of the PCS 102 via a smoothing capacitor C and a reactor Ldc for ripple current generated during AC / DC conversion.

  The SOC determination device 200 is electrically connected between the smoothing capacitor C and the reactor Ldc, and the charge / discharge current detection means 201 detects the current. From the current detection value detected by the charging / discharging current detection means 201, the ripple extraction means 202 and the average value calculation unit 203 extract the ripple and the DC component, and the ratio of the ripple to the DC component, that is, the pulsation rate is divided by the divider 204. And stored in the storage unit 205. In addition to the pulsation rate calculated from the detected current, the storage unit 205 stores a pulsation rate-SOC database in which changes in the pulsation rate with respect to changes in the SOC measured in advance are stored. The SOC can be determined by comparing the pulsation rate detected by the charge / discharge current detection means 201 with the pulsation rate-SOC database. The determination result of the SOC determination unit 206 can be displayed by the determination result display unit 207.

  As a simpler SOC determination method for the storage battery 103, there is a method that does not use the pulsation rate-SOC database of the storage unit 205. In this method, the SOC determination device 206 can determine the SOC from only the pulsation rate by determining whether or not the pulsation rate falls below a preset threshold value.

  2 (a) and 2 (b) show the measurement results of the pulsation rate with respect to the SOC measured by the SOC determination device according to Embodiment 1 of the present invention in the main circuit configuration of the single-phase power storage PCS of FIG. 1 (a). Show. FIG. 2 (a) shows the results measured during discharging, and FIG. 2 (b) shows the results measured during charging. Moreover, a lead storage battery was used as the storage battery, and a resistor was connected in series with the storage battery in order to simulate the aging of the storage battery.

  From the results of FIGS. 2A and 2B, it can be seen that when the SOC is about 40% or more, the change amount of the SOC with respect to the change amount of the pulsation rate is constant regardless of the degree of deterioration. From this, for example, if the amount of change from the reference pulsation rate is measured with reference to the pulsation rate when the SOC is 100%, the SOC can be determined regardless of the degree of deterioration.

  Further, as shown in FIG. 2 (a), when there is no resistance, the pulsation rate starts to decrease greatly when the SOC is about 35%, and when the internal resistance increases due to aged deterioration, the SOC gradually begins to decrease. Get higher. Furthermore, when the internal resistance increases due to deterioration over time, the amount of decrease in the pulsation rate when the SOC decreases is also increased. Based on these characteristics, the SOC corresponding to the pulsation rate is set higher as the SOC starts to greatly decrease, thereby changing the amount of charge from the pulsation rate even if it deteriorates over time. It is possible to grasp, particularly the state at the end of discharge, and to prevent overdischarge.

(Embodiment 2)
In order to protect the storage battery 103, it is necessary to reduce the ripple voltage and the ripple current applied to the storage battery 103. Therefore, a smoothing capacitor and a reactor for removing ripples are generally installed on the DC side of the PCS 102. In addition, when the power supply voltage is as low as 100 V or less, a large-capacity capacitor can be used relatively easily. Therefore, the smoothing capacitor alone can be configured as shown in FIG. In this case, the SOC determination apparatus 200 according to the first embodiment is connected between the capacitor C and the storage battery 103 to detect a ripple current flowing into the storage battery 103.

  4 (a) and 4 (b), in the main circuit configuration of the single-phase power storage PCS having no reactor in the smoothing circuit of FIG. 3, the pulsation with respect to the SOC measured by the SOC determination device according to the first embodiment of the present invention. The measurement result of a rate is shown. FIG. 4A shows the result measured at the time of discharging, and FIG. 4B shows the result measured at the time of charging. Moreover, a lead storage battery was used as the storage battery, and a resistor was connected in series with the storage battery in order to simulate the aging of the storage battery.

  When this result is compared with the case of the first embodiment in which the DC side smoothing circuit has a reactor, the change in the pulsation rate with respect to the charge amount is smoother and continuous in the main circuit configuration of the single-phase PCS having no reactor on the DC side. Is. As described above, when the main circuit configuration of the single-phase PCS having no reactor on the DC side is adopted, it is possible to estimate a more accurate approximate value of the charge amount from the pulsation rate. Also, unlike the case of the first embodiment, the SOC change amount with respect to the pulsation rate change amount changes depending on the degree of deterioration. Therefore, for example, the SOC can be determined from the pulsation rate regardless of the degree of deterioration by setting the change amount of the SOC with respect to the change amount of the pulsation rate according to the pulsation rate when the SOC is 100%.

  As shown in FIGS. 4 (a) and 4 (b), as the aging progresses and the internal resistance increases, the pulsation rate at SOC 100% greatly decreases, but the aging deteriorates as the SOC decreases. The accompanying decrease in pulsation rate is reduced. From this, in order to grasp the aging deterioration, it is desirable to measure the change in the pulsation rate when the SOC is 100%. Further, as the aging progresses, it becomes difficult to grasp the change in the SOC from the pulsation rate, but the pulsation rate at the end of discharge becomes substantially the same pulsation rate regardless of the degree of deterioration. Therefore, the state at the end of discharge can always be grasped from the pulsation rate to prevent overdischarge.

  As in the first embodiment, the storage unit 205 stores a pulsation rate-SOC database in which changes in pulsation rate with respect to changes in SOC measured in advance are stored, and the SOC determination unit 206 detects the pulsation rate detected. And the pulsation rate-SOC database can be compared to determine the SOC.

  In addition, even if the power supply voltage is a high voltage exceeding 100 V, the applied voltage of the DC side capacitor is reduced to a voltage at which a general-purpose capacitor can be used by adopting the low voltage battery multiplexed inverter system shown in FIG. In addition, a DC side reactor can be eliminated. Thereby, it is possible to easily estimate the amount of charge due to the change in the pulsation rate even for a high-voltage power supply.

(A) is a figure which shows the main circuit structure of the single phase power storage PCS which has a reactor in a smoothing circuit, (b) is a figure which shows the structure of the SOC determination apparatus which concerns on Embodiment 1 of this invention. In the main circuit configuration of the single-phase power storage PCS of FIG. 1 (a), it is a measurement result of the pulsation rate with respect to the SOC measured by the SOC determination device according to Embodiment 1 of the present invention, and (a) is a measurement at the time of discharge. It is a figure which shows a result, (b) is a figure which shows the measurement result at the time of charge. It is a figure which shows the main circuit structure of the single phase power storage PCS which does not have a reactor in a smoothing circuit. In the main circuit configuration of the single-phase power storage PCS having no reactor in the smoothing circuit of FIG. 3, the measurement result of the pulsation rate with respect to the SOC measured by the SOC determination device according to the first embodiment of the present invention is as follows: Is a figure which shows the measurement result at the time of discharge, (b) is a figure which shows the measurement result at the time of charge. It is a figure which shows the structure of a low voltage battery multiplexing inverter system.

Explanation of symbols

100 single-phase PCS circuit 101 AC single-phase power supply 102 PCS
DESCRIPTION OF SYMBOLS 103 Storage battery 200 SOC determination apparatus 201 Charge / discharge current detection means 202 Ripple extraction means 203 Average value calculation means 204 Divider 205 Storage means 206 SOC determination means 207 Determination result display means 301 Switch

Claims (13)

An SOC determination device that determines a charge amount (SOC) of a storage battery included in a single-phase power storage AC / DC converter,
Current detecting means for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that separates the current value detected by the current detection unit into a ripple component and a DC component, and calculates a pulsation rate that is a ratio to the DC component of the ripple;
An SOC determination device, comprising: SOC determination means for determining an SOC of the storage battery based on a change amount of the pulsation rate based on the pulsation rate at a predetermined SOC. An SOC determination device that determines a charge amount (SOC) of a storage battery included in a single-phase power storage AC / DC converter,
Current detecting means for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that calculates a pulsation rate that is a ratio of the ripple relative to the DC component with respect to the current value detected by the current detection unit;
Storage means for storing pulsation rate-SOC correspondence data in which a pulsation rate according to a parameter representing the state of the storage battery and SOC are related;
SOC determining means for determining the SOC of the storage battery by comparing the pulsation rate-SOC correspondence data read from the storage means corresponding to the parameter representing the state of the latest storage battery and the pulsation rate ;
The parameter indicating the state of the storage battery is specified based on the SOC calculated by integrating the charging current and the discharging current, and the pulsation rate lowering rate when the SOC and SOC lowering starts. , And a pulsation rate when the SOC is 100% .   3. The SOC determination device according to claim 1, wherein the SOC determination unit determines that the discharge end stage is detected when it is detected that the rate of change of the pulsation rate has changed significantly. 4. A single-phase power storage AC / DC converter having a storage circuit and a smoothing circuit not including a reactor on the DC side;
Current detecting means for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that calculates a pulsation rate that is a ratio of the ripple relative to the DC component with respect to the current value detected by the current detection unit;
An SOC determination device comprising: SOC determination means for determining an SOC of the storage battery based on a change amount of the SOC with respect to a change amount of the predetermined pulsation rate according to the pulsation rate at a predetermined SOC. A single-phase power storage AC / DC converter having a storage circuit and a smoothing circuit not including a reactor on the DC side;
Current detecting means for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that calculates a pulsation rate that is a ratio of the ripple relative to the DC component with respect to the current value detected by the current detection unit;
Storage means for storing pulsation rate-SOC correspondence data in which a pulsation rate according to a parameter representing the state of the storage battery and SOC are related;
SOC determining means for determining the SOC of the storage battery by comparing the pulsation rate-SOC correspondence data read from the storage means corresponding to the parameter representing the state of the latest storage battery and the pulsation rate ;
The parameter indicating the state of the storage battery is specified based on the SOC calculated by integrating the charging current and the discharging current, and the pulsation rate lowering rate when the SOC and SOC lowering starts. , And a pulsation rate when the SOC is 100% . A single-phase power storage AC / DC converter having a storage battery and a single-phase power storage converter having a smoothing circuit that does not include a reactor on the DC side, and the plurality of single-phase power storage converters connected in series;
Current detecting means for selectively detecting the current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that calculates a pulsation rate that is a ratio of the ripple relative to the DC component with respect to the current value detected by the current detection unit;
An SOC determination device comprising: SOC determination means for determining an SOC of the storage battery based on a change amount of the SOC with respect to a change amount of the predetermined pulsation rate according to the pulsation rate at a predetermined SOC. A single-phase power storage AC / DC converter having a storage battery and a single-phase power storage converter having a smoothing circuit that does not include a reactor on the DC side, and the plurality of single-phase power storage converters connected in series;
Current detecting means for selectively detecting the current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating unit that calculates a pulsation rate that is a ratio of the ripple relative to the DC component with respect to the current value detected by the current detection unit;
Storage means for storing pulsation rate-SOC correspondence data in which a pulsation rate according to a parameter representing the state of the storage battery and SOC are related;
The SOC of the storage battery is determined by comparing the pulsation rate-SOC correspondence data read from the storage unit corresponding to the parameter representing the state of the latest storage battery with the pulsation rate calculated by the pulsation rate calculation unit. An SOC determination means ,
The parameter indicating the state of the storage battery is specified based on the SOC calculated by integrating the charging current and the discharging current, and the pulsation rate lowering rate when the SOC and SOC lowering starts. , And a pulsation rate when the SOC is 100% .   The SOC according to any one of claims 4 to 7, wherein the SOC determination means determines that the storage battery is in an end-of-discharge period when detecting that the pulsation rate is equal to or less than a preset threshold value. Judgment device.   The SOC determination apparatus according to claim 1, wherein the predetermined SOC is 100%. An SOC determination method for determining the SOC of a storage battery of a single-phase power storage AC / DC converter,
A current detection step for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating step of separating a current value detected by the current detection means into a ripple component and a DC component, and calculating a pulsation rate that is a ratio to the DC component of the ripple;
And a SOC determination step of determining an SOC of the storage battery based on an amount of change of the pulsation rate based on the pulsation rate at a predetermined SOC. An SOC determination method for determining the SOC of a storage battery of a single-phase power storage AC / DC converter,
A current detection step for detecting a current flowing into the storage battery and discharged from the storage battery;
A pulsation rate calculating step of separating a current value detected by the current detection means into a ripple component and a DC component, and calculating a pulsation rate that is a ratio to the DC component of the ripple;
The pulsation rate corresponding to the latest parameter representing the state of the storage battery, read from the storage means storing the pulsation rate-SOC correspondence data in which the pulsation rate according to the parameter representing the state of the storage battery and the SOC are associated with each other. possess a -SOC correspondence data, and a SOC determination step of determining SOC of the battery by collating the calculated ripple factor by the pulsation ratio calculating means,
The parameter indicating the state of the storage battery is specified based on the SOC calculated by integrating the charging current and the discharging current, and the pulsation rate lowering rate when the SOC and SOC lowering starts. , And a pulsation rate when the SOC is 100% .   12. The SOC determination method according to claim 10, wherein the SOC determination step determines that it is the end of discharge when it is detected that the rate of change of the pulsation rate has changed significantly.   The SOC determination method according to claim 10, wherein the predetermined SOC is 100%.

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