JP4152376B2 - Regenerative control system and regenerative control device used therefor - Google Patents

Description

  The present invention relates to a regenerative control system used for a motorcycle or the like, and more particularly to a regenerative control system that charges a secondary battery with regenerative power from a load. Moreover, this invention relates to the regeneration control apparatus used for this regeneration control system.

  Lithium ion batteries (LiB) have advantages such as high energy density and high output voltage per cell, and are therefore used in various devices. Since a lithium ion battery deteriorates or breaks when it is overdischarged, overcharged, or overcurrent, a protection circuit that protects the lithiumion battery from overdischarge, overcharge, or overcurrent is required.

  Such a protection circuit is often built in a battery unit such as a so-called battery pack. The built-in protection circuit prevents the voltage of the lithium ion battery from falling below the lower limit voltage (for example, 2.5 V) (so as not to cause overdischarge), and the voltage of the lithium ion battery to the upper limit voltage (for example, 4.2 V). Lithium ion battery so that the discharge current and charge current of the lithium ion battery do not exceed the upper limit current (for example, 5 amperes) (so as not to become overcurrent). Controls charging and discharging of For this reason, the protection circuit includes at least a voltage sensor for detecting the voltage of the lithium ion battery and a current sensor for detecting a current flowing through the lithium ion battery.

  FIG. 12 shows a conventional discharge / regeneration comprising a battery unit (battery pack) 101 having such a protection circuit and a discharge / regeneration control device 102 (regeneration control device 102) to which the battery unit 101 can be attached and detached. A control system (regenerative control system) will be described.

  The battery unit 101 includes a secondary battery 111 composed of a single (one cell) lithium ion battery, a first current detector 112 for detecting a current flowing through the secondary battery 111, and the secondary battery. The first voltage detector 113 for detecting the voltage of 111, a microcomputer, etc., and based on the detection result of the first current detector 112 and the detection result of the first voltage detector 113, the secondary A battery-side control unit 114 that controls charging / discharging of the secondary battery 111 so that the battery 111 is not overdischarged, overcharged, or overdischarged, and a pair of input / output terminals (115a, 115b).

  The discharge / regeneration control device 102 includes a pair of input / output terminals 121a to be connected to the input / output terminals 115a on the battery unit 101 side and input / output terminals 121b to be connected to the input / output terminals 115b on the battery unit 101 side. Input / output terminals (121a, 122b), a second current detector 122 for detecting a current flowing through the input / output terminal 121a (or input / output terminal 121b), and a load of an inverter 125 described later. A motor 124 for rotating the tire and the like, an inverter 125 for driving the motor 124, a second voltage detector 123 for detecting a voltage applied to the inverter 125, and a discharge / regeneration control unit 126 for controlling the inverter 125 And is roughly composed of.

  The inverter 125 converts (forward conversion) the discharge power of the secondary battery 111 into the drive power of the motor 124 when the motor 124 is driven, and the charge power of the secondary battery 111 when the power from the motor 124 is regenerated. Convert back to. The discharge / regeneration control unit 126 supplies a control signal to the inverter 125 based on the detection result of the second current detector 122 and the detection result of the second voltage detector 123, thereby performing forward conversion (of the motor 124). Driving) and reverse conversion (regeneration of electric power from the motor 124).

  The battery unit 101 is configured to be connectable to a charger (not shown). When the battery unit 101 is connected to the charger, the secondary battery 111 is charged.

FIG. 13 is a diagram illustrating a charging current when the secondary battery 111 is charged by a charger. In FIG. 13, the horizontal axis represents time, and the vertical axis represents the charging current by the charger. This charging is performed under the condition that the charging current does not exceed a predetermined upper limit current I _L (for example, 5 amperes), and the difference between the voltage between both electrodes of the secondary battery 111 and a predetermined charging control voltage value is This is done to get smaller (approaching to zero). Note that the voltage between both electrodes of the secondary battery 111 at this time is a voltage detector that detects the voltage between the pair of input / output terminals (115a, 115b) provided in the first voltage detector 113 or the charger. (Not shown).

Therefore, as shown in FIG. 13, in the initial charge, the secondary battery 111 is charged with a constant current (charging upper limit current I _L), then charged at a constant voltage (the charge control voltage value). This charge control voltage value is as high as possible under the condition that the secondary battery 111 is not overcharged. This is for charging the secondary battery 111 to the maximum extent. In the lithium ion battery, the charge control voltage value is, for example, 4.2V.

When the charging current continues to charge at the charge control voltage value is gradually reduced, lowered to stop charging current I _F to a predetermined, to stop charging. Thereby, the secondary battery 111 is charged to an almost ideal capacity.

  Patent Document 1 listed below discloses a battery and power that converts battery discharge power into load drive power when driving the load, and reversely converts load drive power into battery charge power during power regeneration from the load. The converter, the voltage detector for detecting the voltage across the battery, the current detector for detecting the current flowing through the battery, and the discharge voltage and discharge current of the battery by the voltage detector and the current detector when driving the load, respectively. A regenerative charging control device is disclosed that includes a control unit that measures, estimates the allowable regenerative power during power regeneration based on the measurement result, and controls the charging power of the battery during power regeneration to be equal to or lower than the allowable regenerative power. Yes.

  Further, in Patent Document 2 below, when a non-aqueous electrolyte secondary battery, which is a power source of a moving body, is regeneratively charged with regenerative power from a motor, a charge control voltage that is an upper limit voltage for charging is temporarily set to a non-aqueous battery. A technique for increasing the overcharge region of an electrolyte secondary battery is disclosed.

JP-A-9-84205 JP 2001-233065 A

In the discharge / regeneration control system of Figure 12, power regeneration, under the condition that the charging current does not exceed the upper limit current I _L, the detected voltage value and a predetermined charge control voltage value by the second voltage detector 123 The discharge / regeneration control unit 126 controls the inverter 125 so that the difference is reduced. However, since there is a difference due to detection error between the detection voltage value by the first voltage detector 113 and the detection voltage value by the second voltage detector 123, the charge control voltage value at the time of power regeneration is charged. If the voltage is set to 4.2 V as in the case of charging with a battery, there is a risk of overcharging.

  Therefore, in order to prevent this overcharge, the charge control voltage value during power regeneration has to be set lower than the charge control voltage value by the charger (for example, 4.0 V). For this reason, as shown in the charging current curve of reference numeral 61 in FIG. 14, the charging is completed in a state where the charging capacity is smaller than the charging by the charger, leading to a decrease in regeneration efficiency and a reduction in the chargeable range. . In addition, FIG. 14 is a figure which shows the charging current at the time of charging the secondary battery 111 by electric power regeneration. In FIG. 14, the horizontal axis is time, and the vertical axis is charging current by power regeneration.

  In addition, the techniques described in Patent Documents 1 and 2 do not solve problems such as a decrease in regeneration efficiency due to the detection error as described above.

  Then, an object of this invention is to provide the regeneration control system which can improve regeneration efficiency, ensuring the safety | security of a secondary battery. Moreover, an object of this invention is to provide the regeneration control apparatus used for the regeneration control system.

  In order to achieve the above object, a regenerative control system according to the present invention includes a battery unit and a regenerative control device, and the battery unit detects a secondary battery and a voltage for detecting the voltage of the secondary battery. And a pair of unit side input / output terminals connected to both electrodes of the secondary battery, and the regenerative control device includes a pair of input terminals to be connected to the pair of unit side input / output terminals. An output terminal, a power conversion means connected to the pair of input / output terminals, for converting the driving force of the load into the charging power of the secondary battery during power regeneration from the load, and a voltage applied to the power conversion means A regeneration control system comprising: a second voltage detection means for detecting; and a control means for controlling the power regeneration by the power conversion means based on a detection result of the second voltage detection means. Control hand Calculates a correction amount for the detection voltage value of the second voltage detection means based on the detection result of the first voltage detection means and the detection result of the second voltage detection means, and uses the correction amount. Then, the power regeneration is controlled based on a corrected voltage value obtained by correcting the detected voltage value of the second voltage detecting means.

  In the regenerative control system, power regeneration control is performed based on the detection result of the second voltage detection means. The detection voltage value of the second voltage detection means depends on the detection result of the first voltage detection means. Corrected. Since the actual power regeneration control is performed based on the corrected voltage value after the correction, the necessity of considering the detection error of the second voltage detection means is eased. Thereby, while ensuring the safety of the secondary battery, the charging voltage to the secondary battery in the power regeneration can be set relatively high, so that the regeneration efficiency can be improved and the chargeable range can be expanded.

  For example, the control means calculates the correction amount based on the detection result of the first voltage detection means and the detection result of the second voltage detection means at a predetermined timing when there is no load. Good.

  Thus, the correction amount is not affected by the wiring resistance between the unit side input / output terminal on the battery unit side and the input / output terminal on the regeneration control device side. Therefore, the regenerative control system can be applied universally to various moving bodies having different wiring resistances between both terminals.

  “No load” refers to a state in which the power conversion means does not drive a load and no power regeneration is performed.

  Specifically, for example, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the total voltage value of each cell is the first voltage detecting unit. The control means calculates the correction amount based on a difference value between the total voltage value at a predetermined timing at no load and the detected voltage value of the second voltage detection means. .

  In addition, for example, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the total voltage value of each cell is obtained by the detection result of the first voltage detection means. The control means acquires the total voltage value and the detection voltage value of the second voltage detection means at each of a plurality of timings when the total voltage value is different from each other, and acquires the acquired voltage values. Based on the value, the correction amount may be calculated as an amount that changes according to the detection voltage value of the second voltage detection means.

  Further, for example, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the first voltage detection unit can individually detect the voltage value of each cell. And the control means is based on a difference value between a voltage value obtained by multiplying the maximum voltage value of the voltage value of each cell at a predetermined timing at no load by the n and a detection voltage value of the second voltage detection means. Then, the correction amount may be calculated.

  When a secondary battery is configured by connecting n cells in series, there may be a relatively large variation in the voltage value of each cell. By configuring as described above, each cell is overcharged. And the safety against deterioration of the secondary battery is improved.

  Further, for example, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the first voltage detection unit can individually detect the voltage value of each cell. The control means includes a voltage value obtained by multiplying the maximum voltage value of the voltage value of each cell by the n and the second voltage at each of a plurality of timings when the total voltage value of each cell is different from each other. The detection voltage value of the detection unit may be acquired, and the correction amount may be calculated as an amount that varies according to the detection voltage value of the second voltage detection unit based on the acquired value.

  When a secondary battery is configured by connecting n cells in series, there may be a relatively large variation in the voltage value of each cell. By configuring as described above, each cell is overcharged. And the safety against deterioration of the secondary battery is improved.

  Further, for example, the control means may control the power conversion means so that a difference between the correction voltage value and a predetermined first charge control voltage value becomes small during power regeneration.

  In addition, for example, the regeneration control system further includes a remaining amount estimating unit that estimates a remaining amount of the secondary battery, and the control unit has a first reference with a predetermined remaining amount during power regeneration. When the capacity is smaller than the capacity, the power conversion means is controlled so that the difference between the correction voltage value and the predetermined first charging control voltage value is small, while the remaining amount is larger than the predetermined first reference capacity. The power conversion means may be controlled so that the difference between the correction voltage value and a predetermined second charge control voltage value smaller than the first charge control voltage value becomes small.

  When the remaining amount reaches the first reference capacity, the secondary battery by power regeneration is reduced by reducing the charge control voltage value related to power regeneration from the first charge control voltage value to the second charge control voltage value. The risk of deterioration and the like can be further reduced.

  In addition to this, for example, when the control unit shifts from a state where the remaining amount is smaller than the first reference capacity to a larger state due to power regeneration, the correction voltage value and the first charge control voltage value The power conversion means may be controlled so as to gradually shift from a state in which control is performed to reduce the difference between the correction voltage value and a state in which control is performed to reduce the difference between the correction voltage value and the second charge control voltage value. .

  When the regenerative control system is applied to a moving body, the braking force in the moving body changes according to the amount of regenerative current (charging current to the secondary battery during power regeneration), but is configured as described above. As a result, the regenerative current changes smoothly. Therefore, the riding comfort of the moving body to which the regeneration control system is applied is improved.

  Further, for example, the regeneration control system further includes remaining amount estimating means for estimating the remaining amount of the secondary battery, wherein the first reference capacity <the second reference capacity and the first charge control voltage value. > Second charge control voltage value> third charge control voltage value, the control means determines that when the remaining amount <first reference capacity is satisfied during power regeneration, the correction voltage value When the power conversion means is controlled so as to reduce the difference from the first charge control voltage value, and the first reference capacity <the remaining amount <the second reference capacity, the correction voltage value When the power conversion unit is controlled so that the difference between the charge control voltage value of 2 and the remaining charge> second reference capacity is satisfied, the correction voltage value and the third charge control voltage value are What is necessary is just to control the said power conversion means so that the difference of may become small.

  As described above, the change in the regenerative current becomes smooth by decreasing the charge control voltage value stepwise. Therefore, when the regenerative control system is applied to a moving body, the riding comfort of the moving body is improved.

  In addition, for example, the control unit may control the power conversion unit during power regeneration under a condition that a charging current to the secondary battery by power regeneration does not exceed a predetermined upper limit current. .

  Further, for example, the regenerative control system further includes a current detection unit for detecting an input / output current of the secondary battery, and the remaining amount estimation unit is the first voltage detection unit when there is no load. After the initial remaining amount is estimated based on the detection result, the remaining amount at an arbitrary time is estimated based on the initial remaining amount and the detection result of the current detection means.

  Further, for example, the regeneration control system further includes a fuel gauge for measuring the remaining amount of the secondary battery, and the remaining amount estimating means includes the first voltage detecting means at the time of no load. After estimating the initial remaining amount based on the detection result, the remaining amount at an arbitrary time is estimated based on the initial remaining amount and the measurement result of the remaining amount meter.

  In order to achieve the above object, a regenerative control device according to the present invention is a regenerative control device to which a battery unit including a secondary battery can be connected, and the second regenerative control device is connected to the second battery via an input / output terminal on the battery unit side. A pair of input / output terminals to be connected to both electrodes of the secondary battery, and an electric power connected to the pair of input / output terminals to convert the driving force of the load to the charging power of the secondary battery at the time of power regeneration from the load A conversion unit; a second voltage detection unit for detecting a voltage applied to the power conversion unit; and a control for controlling the power regeneration by the power conversion unit based on a detection result of the second voltage detection unit. In the regenerative control device, the control means, based on the information on the voltage of the secondary battery transmitted from the battery unit and the detection result of the second voltage detection means, Voltage A correction amount for the detection voltage value of the output means is calculated, and the power regeneration is controlled based on the correction voltage value obtained by correcting the detection voltage value of the second voltage detection means using the correction amount. To do.

  In addition, for example, in the regenerative control device, the control unit is configured to adjust the correction amount based on the information on the voltage of the secondary battery at a predetermined timing when there is no load and a detection result of the second voltage detection unit. May be calculated.

  In addition, for example, in the regenerative control device, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the information regarding the voltage of the secondary battery is each cell. And the control means calculates the correction amount based on a difference value between the total voltage value at a predetermined timing at no load and a detected voltage value of the second voltage detecting means. calculate.

  In addition, for example, in the regenerative control device, the secondary battery is configured by connecting n (n is an integer of 2 or more) cells in series, and the information regarding the voltage of the secondary battery is each cell. The control means is a voltage value obtained by multiplying the maximum voltage value of the voltage value of each cell at a predetermined timing when there is no load by the n and a detection voltage of the second voltage detection means. The correction amount is calculated based on a difference value from the value.

  According to the regeneration control system or the regeneration control device according to the present invention, it is possible to improve the regeneration efficiency while securing the safety of the secondary battery.

  Hereinafter, embodiments of the present invention will be specifically described with reference to the drawings. FIG. 1 shows a block diagram of a discharge / regeneration control system to which the present invention is applied. This discharge / regenerative control system can be any device that charges a secondary battery with regenerative power in addition to a moving body such as a motor vehicle (electric vehicle) or a motorcycle (so-called motorcycle or electric bicycle) driven by a motor or the like. It is applicable to any device. If attention is paid to the function of power regeneration, the discharge / regeneration control system of FIG. 1 can also be called a regeneration control system.

(Fig. 1: Overall configuration)
The discharge / regeneration control system (regeneration control system) in FIG. 1 includes a battery unit 1 and a discharge / regeneration control device 2. If attention is paid to the function of power regeneration, the discharge / regeneration control device 2 in FIG. 1 can also be called the regeneration control device 2.

  The battery unit 1 includes a secondary battery 11 made of a lithium ion battery (LiB), a first current detector 12 for detecting a current flowing through the secondary battery 11, and a voltage of the secondary battery 11. The secondary battery 11 is overdischarged based on the detection result of the first current detector 12 and the detection result of the first voltage detector 13. The battery side control unit 14 that controls charging / discharging of the secondary battery 11 so as not to overcharge or overcurrent, and the positive electrode (positive voltage output side) 11a of the secondary battery 11 via the first current detector 12 Connected to the unit side input / output terminal 15a (hereinafter simply referred to as “input / output terminal 15a”) and the negative side (negative voltage output side) 11b of the secondary battery 11 (hereinafter simply referred to as “input / output terminal 15a”). "Input / output terminal 15b A pair of unit side output terminal consisting of) that (15a, 15b), schematically composed.

  The secondary battery 11 is configured by connecting n (n is an integer of 2 or more) lithium ion battery cells in series. However, the present invention can be applied to a secondary battery composed of a single lithium ion battery cell or a secondary battery configured by connecting a plurality of lithium ion battery cells in parallel. It is. In addition, the secondary battery 11 is not limited to what is comprised from a lithium ion battery. That is, the present invention can be applied to all the secondary batteries that need to control the voltage value of the charging voltage.

  Moreover, the positive electrode 11a of the secondary battery 11 refers to the positive electrode of the cell having the highest potential among the cells connected in series, and the negative electrode 11b of the secondary battery 11 is the most of the cells connected in series. It refers to the negative electrode of a cell having a low potential. The positive electrode 11 a and the negative electrode 11 b are collectively referred to as both electrodes of the secondary battery 11.

  The first current detector 12 is constituted by a resistor (not shown) connected in series between the positive electrode 11a of the secondary battery 11 and the input / output terminal 15a, for example. By supplying a signal based on the voltage drop value of the resistor to the battery-side control unit 14, the battery-side control unit 14 recognizes the current value of the current flowing through the secondary battery 11.

  The first voltage detector 13 can individually detect the voltage value of each cell constituting the secondary battery 11. For example, in the first voltage detector 13, the voltage between both electrodes of each cell is divided by a voltage dividing resistor (not shown), and the divided analog voltage is converted into a digital signal by an A / D converter (not shown). Convert to Then, the digital signal is supplied to the battery side control unit 14. Thereby, the battery side control unit 14 recognizes the voltage value of each cell constituting the secondary battery 11.

  The battery-side control unit 14 stops the discharge of the secondary battery 11 immediately before the secondary battery 11 is overdischarged so that the secondary battery 11 is not overdischarged. Overdischarge refers to a discharge in which the voltage of each cell of the secondary battery falls below a predetermined lower limit voltage (for example, 2.5 V). Moreover, the charging to the secondary battery 11 is stopped immediately before the secondary battery 11 is overcharged so that the secondary battery 11 is not overcharged. Overcharging refers to charging in which the voltage of each cell of the secondary battery 11 exceeds a predetermined upper limit voltage (for example, 4.2 V). For example, immediately before overdischarge or overcharge occurs, the battery-side control unit 14 controls a switch element (for example, a field effect transistor) (not shown) connected in series to the secondary battery 11 so that the secondary battery 11 Or discharging the secondary battery 11 is cut off.

Further, the battery-side control unit 14 prevents the secondary battery 11 from becoming overcurrent, that is, the discharge current and the charge current of the secondary battery 11 exceed a preset upper limit current I _L (for example, 5 amperes). There is a limit to the magnitude of the discharge current and charge current so that there is no such problem. In addition, for simplicity of explanation, the upper limit current of the discharge current and the upper limit current of the charging current are described as matching. However, the upper limit current of the discharge current and the upper limit current of the charging current may not match. is there. Further, the value of the upper limit current I _L varies depending on the configuration of the secondary battery 11.

  The battery unit 1 is configured to be connectable to a charger (not shown), and when the battery unit 11 is connected to the charger, the secondary battery 11 is charged. That is, the secondary battery 11 can be charged by connecting the pair of input / output terminals (15a, 15b) to the charging current output terminal of the charger. Charging by the charger is the same as that shown in FIG.

  The battery unit 1 can also be connected to a discharge / regeneration control device 2. In other words, the discharge / regeneration control device 2 is configured such that the battery unit 1 is detachable. FIG. 1 shows a state in which the battery unit 1 is connected to the discharge / regeneration control device 2. Hereinafter, a state in which the battery unit 1 is connected to the discharge / regeneration control device 2 unless otherwise specified. explain. Further, when the battery unit 1 is connected to the discharge / regeneration control device 2, the battery-side control unit 14 on the battery unit 1 side and the discharge / regeneration control unit 26 on the discharge / regeneration control device 2 side can communicate. Information to be communicated and operations based on the information will be described later.

  The discharge / regeneration control device 2 (regeneration control device 2) includes an input / output terminal 21a to be connected to the input / output terminal 15a on the battery unit 1 side and an input / output terminal to be connected to the input / output terminal 15b on the battery unit 1 side. A pair of input / output terminals (21a, 21b) composed of 21b, a second current detector 22 for detecting a current flowing through the input / output terminal 21a (or the input / output terminal 21b), and an inverter 25 described later. A motor 24 for rotating a tire or the like of an automobile, an inverter 25 for driving the motor 24, a second voltage detector 23 for detecting a voltage applied to the inverter 25, a microcomputer, etc. Based on the information transmitted from the battery side control unit 14, the detection result of the second current detector 22 and the detection result of the second voltage detector 23. A discharge / regenerative control unit 26 for controlling the over motor 25, schematically composed.

  The input / output terminal 21a may be directly connected to the input / output terminal 15a on the battery unit 1 side, or may be connected via a wiring. Similarly, the input / output terminal 21b may be directly connected to the input / output terminal 15b on the battery unit 1 side, or may be connected via a wiring.

  The second current detector 22 is composed of a resistor (not shown) connected in series between the input / output terminal 21a and the inverter 25, for example. By supplying a signal based on the voltage drop value of the resistor to the discharge / regeneration control unit 26, the discharge / regeneration control unit 26 sets the current value of the current flowing through the input / output terminal 21a (or the input / output terminal 21b). recognize. This current value is equal to the current value of the current flowing through the inverter 25.

  The positive voltage side terminal 25a of the inverter 25 is connected to the input / output terminal 21a via the second current detector 22, and the negative voltage side terminal 25b of the inverter 25 is connected to the input / output terminal 21b.

  In the second voltage detector 23, for example, a voltage applied to the inverter 25, that is, a voltage applied between the positive voltage side terminal 25 a and the negative voltage side terminal 25 b is divided by a voltage dividing resistor (not shown). The pressed analog voltage is converted into a digital signal by an A / D converter (not shown). The digital signal is supplied to the discharge / regeneration control unit 26. Thereby, the discharge / regeneration control unit 26 recognizes the voltage applied to the inverter 25.

  In grasping the essence of the present invention, the voltage drop in the wiring connecting the pair of input / output terminals (21a, 21b) and the inverter 25 or the second current detector 22 can be ignored. Therefore, the voltage value between the pair of input / output terminals (21a, 21b) is equal to the voltage value applied to the inverter 25, and the function of “detecting the voltage applied to the inverter 25” of the second voltage detector 23 is “ This is synonymous with a function of “detecting a voltage applied between the pair of input / output terminals (21a, 21b)”. In addition, the second voltage detector 23 may be provided between the pair of input / output terminals (21a, 21b) and the second current detector 22.

(Figure 2: Details of the inverter)
FIG. 2 shows details of the configuration of the inverter 25 and details of the connection relationship between the motor 24, the inverter 25, and the discharge / regeneration control unit 26. In FIG. 2, the same parts as those in FIG.

  The inverter 25 includes six N-channel (N-type semiconductor) MOS transistors (insulated gate type field effect transistors) Tr1, Tr2, Tr3, Tr4, Tr5, and Tr6. Parasitic diodes D1, D2, D3, D4, D5, and D6 are added to the MOS transistors Tr1, Tr2, Tr3, Tr4, Tr5, and Tr6, respectively. The direction from the source side to the drain side of each MOS transistor is the forward direction of each parasitic diode.

  The drains of the MOS transistors Tr1, Tr3, Tr5 are commonly connected to the positive voltage side terminal 25a of the inverter 25, and to the input / output terminal 21a via the positive voltage side terminal 25a and the second current detector 22. Commonly connected. The sources of the MOS transistors Tr2, Tr4, Tr6 are commonly connected to the negative voltage side terminal 25b of the inverter 25 and are commonly connected to the input / output terminal 21b via the negative voltage side terminal 25b.

  The motor 24 is, for example, a three-phase permanent magnet synchronous motor in which a permanent magnet is provided on a rotor (not shown) and an armature winding is provided on a stator (not shown). One end of the U-phase armature winding Lu is commonly connected to the source of the MOS transistor Tr1 and the drain of the MOS transistor Tr2, and one end of the W-phase armature winding Lw is connected to the source of the MOS transistor Tr3 and the MOS transistor. Commonly connected to the drain of Tr4, one end of the V-phase armature winding Lv is commonly connected to the source of the MOS transistor Tr5 and the drain of the MOS transistor Tr6. The other ends of the three armature windings Lu, Lv, and Lw are commonly connected.

  The gates of the MOS transistors Tr1, Tr2, Tr3, Tr4, Tr5, and Tr6 are connected to the discharge / regeneration control unit 26 separately.

  When the motor 24 is driven, the discharge / regeneration control unit 26 supplies control signals to the gates of the MOS transistors Tr1, Tr2, Tr3, Tr4, Tr5, and Tr6, so that the armature windings Lu, Lv, and Lw are supplied. A three-phase AC voltage is supplied, and drive control of the motor 24 is performed. That is, when the motor 24 is driven, the discharge power of the secondary battery 11 is supplied to the inverter 25 and converted into the driving force of the motor 24.

  On the other hand, at the time of power regeneration from the motor 24, the rotational energy (driving force) of the motor 24 is converted into electric energy through the inverter 25, the secondary battery 11 is charged, and the motor 24 (to the motor 24) is charged. The regenerative brake is applied to the moving body etc. That is, at the time of power regeneration from the motor 24, the driving force of the motor 24 is reversely converted to the charging power of the secondary battery 11.

  Thus, the inverter 25 converts (forward conversion) the discharge power of the secondary battery 11 into the driving force of the motor 24 when the motor 24 is driven, and converts the driving force of the motor 24 to the secondary battery when the power from the motor 24 is regenerated. It functions as a power conversion means for converting back to 11 charging power. The inverter 25 as the power conversion means is an example, and any circuit configuration may be adopted as long as it can perform forward conversion and reverse conversion as described above.

  The discharge / regeneration control unit 26 is a MOS that configures the inverter 25 based on the information given from the battery side control unit 14, the detection result of the second current detector 22, and the detection result of the second voltage detector 23. The power regeneration is controlled by controlling the transistors Tr1 to Tr6.

  When the motor voltage is lower than the voltage between both electrodes of the secondary battery 11, the discharge / regeneration control unit 26 boosts the motor voltage and performs power regeneration. For example, among the U phase, V phase, and W phase, when the voltage in the W phase is the highest and the voltage in the U phase is the lowest, as shown in FIG. 3, armature windings Lw, Lu, MOS transistors The step-up chopper is configured by Tr1 and parasitic diodes D2 and D3, and the discharge / regeneration control unit 26 switches on / off of the MOS transistor Tr1, thereby performing the step-up operation and charging the secondary battery 11.

  In FIG. 3, when the MOS transistor Tr1 is on, current flows through the armature windings Lw and Lu via the parasitic diode D3 and the drain-source of the MOS transistor Tr1, and energy is supplied to the armature windings Lw and Lu. When the MOS transistor Tr1 is stored, the stored energy is supplied to the secondary battery 11 via the parasitic diodes D3 and D2.

  During power regeneration when the voltage in the W phase is the highest and the voltage in the U phase is the lowest, the voltage between the pair of input / output terminals (21a, 21b) (the voltage applied to the inverter 25) is the transistor Tr1. It is controlled by controlling the duty ratio of the ON period.

  The boost chopper is similarly configured when the voltage in the V phase is the highest, the voltage in the U phase is the lowest, the voltage in the U phase is the highest, and the voltage in the W phase is the lowest. Then, power regeneration control is performed. Accordingly, the discharge / regeneration control unit 26 refers to the detection result of the second voltage detector 23 and controls the on / off of the MOS transistors Tr1 to Tr6, whereby a pair of input / output terminals ( 21a and 21b) (voltage applied to the inverter 25) can be adjusted to an arbitrary voltage.

(Calculation method of correction amount ΔV)
A more detailed description will be given of what voltage value is used to control the power regeneration. The discharge / regeneration control unit 26 acquires information based on the detection result of the first voltage detector 13 from the battery-side control unit 14 by communication. Then, the “voltage value obtained from the detection result of the first voltage detector 13” (hereinafter referred to as “voltage value V1” or “V1”) and the inverter 25 detected by the second voltage detector 23 are added. Using the voltage value (hereinafter referred to as “detected voltage value V2” or “V2”), a correction amount (hereinafter referred to as “correction amount ΔV” or “ΔV”) for the detected voltage value V2 is calculated. Then, the inverter 25 is controlled based on a voltage value obtained by correcting the detected voltage value V2 using the calculated correction amount ΔV (hereinafter referred to as “corrected voltage value Vq” or “Vq”). That is, power regeneration is controlled based on the correction voltage value Vq.

  The voltage value V <b> 1 is, for example, a total value (total voltage value) of voltage values of cells constituting the secondary battery 11. This is equal to the voltage between both electrodes of the secondary battery 11 (between the positive electrode 11a and the negative electrode 11b).

  Information necessary for calculating the correction amount ΔV is acquired when there is no load. “No load” means a state in which the inverter 25 is not driving the motor 24 and power regeneration from the motor 24 is not performed. Therefore, no current flows through the inverter 25 when there is no load. Further, if all the discharge power of the secondary battery 11 is consumed by the inverter 25 and the motor 24, the current flowing through the secondary battery 11 is zero when there is no load.

  Hereinafter, a specific method for calculating the correction amount ΔV, which is a value necessary for calculating the correction voltage value V, will be described in detail. As a calculation method of the correction amount ΔV, any one of a first correction amount calculation method and a second correction amount calculation method described below can be adopted.

((FIG. 4; first correction amount calculation method))
A first correction amount calculation method will be described. The first correction amount calculation method is such that the first voltage detector 13 detects the voltage of the secondary battery 11 and the second voltage detector 23 is the inverter 25 at a predetermined timing Ta when there is no load. The voltage applied to is detected. Note that both voltages need not be detected completely at the same time, but may be detected within a certain period. Therefore, the timing Ta should be considered as a period having a certain width (for example, several nanoseconds to several hundred milliseconds). The same applies to timings Tb, Tc, and Td described later.

The voltage value V1 (for example, the total voltage value of each cell) is calculated from the detection result of the first voltage detector 13 at the timing Ta. The voltage value V1 at the timing Ta is referred to as “V1 _a ”. Further, the detection voltage value V2 of the second voltage detector 23 at the timing Ta is referred to as “V2 _a ”.

In this case, the discharge / regeneration control unit 26 calculates the correction amount ΔV by the following equation (1). That is, the magnitude of the correction amount ΔV is the difference value between the voltage value V1 (ie, V1 _a ) and the detected voltage value V2 (ie, V2 _a ) at the no-load timing Ta.
ΔV = V1 _a −V2 _a (1)

After the correction amount ΔV is calculated by the above equation (1), the correction voltage value Vq is expressed by the following equation (2) at an arbitrary timing during power regeneration. V2 in the following formula (2) is a detection voltage value V2 that is detected one after another during power regeneration, and changes (can change) every moment, but the value of ΔV = V1 _a −V2 _a is constant. Value.
Vq = V2 + ΔV = V2 + V1 a -V2 a ··· (2)

However, the first voltage detector 13 detects the voltage of the secondary battery 11 and the second voltage detector 23 detects the voltage applied to the inverter 25 at another timing Tb when there is no load after the timing Ta. and, the (referred to as V1 _b) the voltage value V1 at the timing Tb and the detected voltage value V2 (referred to as V2 _b) using the value of the correction amount [Delta] V, be updated with the calculated value of the formula (3) It doesn't matter (it doesn't matter).
ΔV = V1 _b −V2 _b (3)

After this update, the correction voltage value Vq is represented by (V2 + V1 _b −V2 _b ). Note that such updating of the correction value ΔV may be repeated a plurality of times. For example, the value of the correction value ΔV may be updated every time a no-load state comes. The detection result of the first voltage detector 13 necessary for updating the correction value ΔV is transmitted from the battery-side control unit 14 to the discharge / regeneration control unit 26 by communication each time.

  FIG. 4 shows how the detected voltage value V2 is corrected when the first correction amount calculation method is employed. FIG. 4 shows the voltage value V1 (shown by reference numeral 50) and the detection voltage value V2 (shown by reference numeral 51) when the detection voltage value V2 is taken on the horizontal axis. The detected voltage value V2 is corrected by the correction amount ΔV and approaches the voltage value V1.

  In addition, since the information necessary for calculating the correction amount ΔV is acquired when there is no load, the unit input / output terminals (15a, 15b) on the battery unit 1 side and the input / output terminals on the discharge / regeneration control device 2 side The wiring resistance between (21a, 21b) can be ignored.

  When the battery unit 1 is used for general purposes, the wiring resistance varies depending on the system to be incorporated. For example, if the battery unit 1 and the discharge / regeneration control device 2 are arranged close to each other, the wiring resistance is relatively small (for example, several tens of milliohms). Originally, it is preferable in terms of energy efficiency that the battery unit 1 and the discharge / regeneration control device 2 are arranged close to each other. However, for example, the discharge / regeneration control device 2 is disposed near the front wheel of the motorcycle, but the battery unit 1 may be disposed only on the rear wheel portion of the motorcycle due to space constraints. In this case, the wiring resistance becomes relatively large (for example, several hundred millimeters to several ohms).

  However, as described above, the correction amount ΔV is not affected by the wiring resistance. This means that the battery unit 1 is extremely versatile, and the discharge / regenerative control device 2 can use such a battery unit that is used for general purposes. .

Specific examples (a) to (e) at no load are listed below.
(A) Immediately after transition from the state where the battery unit 1 and the discharge / regeneration control device 2 are not connected to the state where they are connected. Usually, immediately after the connection, the motor 24 is stopped and is in a no-load state.
(B) When the discharge / regeneration control device 2 is provided with a power switch (not shown) for turning on / off the operation of each part of the discharge / regeneration control device 2, the power / switch is turned on to discharge / Immediately after the operation of each part of the regeneration control device 2 is turned on. Normally, immediately after the power switch is turned on, the motor 24 is stopped and is in a no-load state.
(C) In the case where the discharge / regeneration control system according to the present embodiment is incorporated in a moving body (such as a bicycle) and the moving body is moved by the rotation of the motor 24, when the moving body is stopped by a red signal or the like, Or during coasting. For example, in a so-called motorcycle, when the throttle is off, it can be during inertial running.
(D) When the discharge / regeneration control unit 26 turns off all the MOS transistors Tr1 to Tr6. For example, when the power regeneration is enabled, the MOS transistor Tr1 or the like is immediately switched to boost the motor voltage and the power regeneration is not performed, but all of the MOS transistors Tr1 to Tr6 are kept for a certain period (for example, several Keep off (microseconds to a few milliseconds). Then, after obtaining information necessary for calculating the correction amount ΔV within this fixed period, the MOS transistor Tr1 and the like are switched to actually perform power regeneration. During the above-mentioned fixed period, the motor 24 is not driven and does not regenerate power, so it is unloaded.
(E) When the battery unit 1 and the discharge / regenerative control device 2 are connected and incorporated in a moving body or the like. This corresponds to the time of manufacture of the discharge / regeneration control system according to the present embodiment or the time of factory shipment.

((FIG. 5; second correction amount calculation method))
Next, the second correction amount calculation method will be described with reference to FIG. FIG. 5 shows an estimated straight line (indicated by reference numeral 52) and a detected voltage value V2 (indicated by reference numeral 53) of the voltage value V1 when the detected voltage value V2 is taken on the horizontal axis. The straight line represented by reference numeral 53 merely represents the straight line “V2 = V2”.

In the second correction amount calculation method, first, the first voltage detector 13 detects the voltage of the secondary battery 11 and the second voltage detector 23 at a predetermined timing Tc when there is no load. Detects the voltage applied to the inverter 25. The voltage value V1 (for example, the total voltage value of each cell) is calculated from the detection result of the first voltage detector 13 at the timing Tc. The voltage value V1 at the timing Tc is referred to as “V1 _c ”. Further, the detection voltage value V2 of the second voltage detector 23 at the timing Tc is referred to as “V2 _c ”.

Next, at another timing Td when no load is different from the timing Tc, the first voltage detector 13 detects the voltage of the secondary battery 11 and the second voltage detector 23 applies the voltage applied to the inverter 25. To detect. The voltage value V1 (for example, the total voltage value of each cell) is calculated from the detection result of the first voltage detector 13 at the timing Td. The voltage value V1 at the timing Td is referred to as “V1 _d ”. Further, the detected voltage value V2 of the second voltage detector 23 at the timing Td is referred to as “V2 _d ”.

However, it is assumed that discharge or power regeneration of a certain power or more occurs between the timing Tc and the timing Td (that is, such timing is adopted as the timing Td). Therefore, V1 _c and V1 _d are different.

Here, in FIG. 5, an estimated straight line V1 = p · V2 + q represented by reference numeral 52 is considered. If this estimated straight line passes through two points (V1, V2) = (V1 _c , V2 _c ), (V1 _d , V2 _d ), p and q are expressed by the following equations (4) and (5), respectively. Both values are calculated by the discharge / regeneration control unit 26.

_{p = (V1 c -V1 d)} / (V2 c -V2 d) ··· (4)
_{q = V1 c -V2 c (V1} c -V1 d) / (V2 c -V2 d) ··· (5)

Then, the discharge / regeneration control unit 26 calculates the correction amount ΔV by the following equation (6). The correction amount ΔV is represented by V1 _c , V2 _c , V1 _d , and V2 _d and V2. That is, the correction amount ΔV is a function of V2, and changes according to V2.
ΔV = (p · V2 + q) −V2 = (p−1) V2 + q (6)

After the correction amount ΔV is calculated by the above equation (6), the correction voltage value Vq is expressed by the following equation (7) at an arbitrary timing during power regeneration. V2 in the following formula (7) is a detection voltage value V2 that is detected one after another during power regeneration, and changes (can change) every moment, but the values of p and q are the above formula (4) and It is a constant value represented by (5).
Vq = V2 + ΔV = p · V2 + q (7)

  This second correction amount calculation method is effective when the slope of the straight line represented by reference numeral 52 is different from the slope of the straight line represented by reference numeral 53.

Moreover, you may deform | transform the said Formula (1), Formula (3), and Formula (6) into following formula (1a), Formula (3a), and Formula (6a), respectively. Along with this deformation, the correction voltage value Vq represented by (V2 + ΔV) also changes. In the following formula (1a), formula (3a), and formula (6a), α can take any positive or negative value.
ΔV = V1 _a −V2 _a + α (1a)
ΔV = V1 _b −V2 _b + α (3a)
ΔV = (p−1) V2 + q + α (6a)

  By setting the value α to a positive appropriate value (for example, 0.2. The unit is volts), the wiring resistance between the secondary battery 11 and the inverter 25 generated during power regeneration and the inside of the secondary battery 11 The voltage drop due to the resistance can be canceled. In addition, by setting the value α to a negative value (for example, 0.05. The unit is volts), the charging voltage of the secondary battery 11 is lowered, and the safety is improved.

((Modification of voltage value V1))
The example in which the voltage value V1 is the total value (total voltage value) of the voltage values of the cells constituting the secondary battery 11 has been given, but the maximum voltage value among the voltage values of the cells of the secondary battery 11 is used. A voltage value multiplied by n (the number of cells constituting the secondary battery 11) may be used as the voltage value V1.

  For example, when the secondary battery 11 is composed of three cells and the voltages of the respective cells detected at no load are 3.7 V, 4.1 V, and 3.9 V, the voltage value V1 is V1 = 4. .1 × 3 = 12.3V.

  Assuming that the upper limit voltage of each cell is 4.2 V and the voltage values of each cell are all equal, charging can be performed until the total voltage value of each cell reaches 12.6 V, but V1 is the sum of the three cells. When the correction amount ΔV is calculated assuming that the voltage value is 11.7V (= 3.7 + 4.1 + 3.9) and power regeneration is performed until the total voltage value reaches 12.6V, 4.1V is obtained before power regeneration. The cell safety is not necessarily sufficient.

  When it is assumed that a relatively large variation occurs in the voltage of each cell, the voltage value V1 is set to the maximum voltage value among the voltage values of each cell of the secondary battery 11 (the secondary battery 11). The voltage value may be multiplied by the number of cells constituting the above. Thereby, the safety | security with respect to degradation etc. of the secondary battery 11 by electric power regeneration improves.

(About power regeneration control using corrected voltage values)
Next, power regeneration control using the correction voltage value Vq calculated as described above will be described. Regarding the power regeneration control method, there are roughly two methods, a first power regeneration control method and a second power regeneration control method, and either of them can be adopted.

((FIG. 6; first power regeneration control method))
First, the first power regeneration control method will be described with reference to FIG. FIG. 6 is a diagram illustrating a charging current when the first power regeneration control method is used. In FIG. 6, the horizontal axis is time, and the vertical axis is charging current by power regeneration.

The discharge / regeneration control unit 26 performs the correction voltage value Vq and the predetermined first charging control voltage value under the condition that the charging current does not exceed a predetermined upper limit current I _L (for example, 5 amperes). The inverter 25 is controlled so that the difference between the two becomes smaller (closer to zero). Thereby, the secondary battery 11 is charged by power regeneration.

  The first charge control voltage value is determined according to the number of cells constituting the secondary battery 11 and the type of the secondary battery 11. When the secondary battery 11 is configured by connecting three lithium ion battery cells in series, the first charge control voltage value is, for example, 4.2 V (upper limit voltage per cell) × 3 = 12. 6V.

  In addition, the discharge / regeneration control unit 26 has already acquired information for calculating the correction amount ΔV before the start of power regeneration.

First, the discharge / regeneration control unit 26 controls the inverter 25 so that the correction voltage value Vq matches the first charge control voltage value (configures a boost chopper as shown in FIG. 3). At this time, if the charging current does not exceed the upper limit current I _L , the correction voltage value Vq is maintained so as to coincide with the first charging control voltage value, and power regeneration is performed with a constant voltage.

If the charging current has reached the upper limit current I _L, in the state in which the charging current is coincident with the upper limit current I _L (i.e., constant current) such that the power regeneration is performed, inverter 25 is controlled. In a period in which power regeneration is performed at a constant current, the correction voltage value Vq is equal to or less than the first charge control voltage value. The discharge / regeneration control unit 26 regards the detected current value detected by the second current detector 22 as a charging current by power regeneration.

FIG. 6 shows an example in which charging is performed at a constant current in the initial stage of charging. When charging by power regeneration proceeds and the remaining amount of the secondary battery 11 increases, the charging current does not reach the upper limit voltage I _L even if the correction voltage value Vq is equal to the first charging control voltage value. . When this state is reached, as shown by a curve 71, power regeneration with the correction voltage value Vq maintained at the first charge control voltage value, that is, power regeneration with a constant voltage, is performed.

Furthermore, when charging by power regeneration is continued, the charging current gradually decreases. When lowered to the charging stop current I _F which charging current is predetermined to stop charging by power regeneration.

  In the conventional configuration example shown in FIG. 12, it is necessary to consider the difference between the detection voltage value of the first voltage detector 113 and the detection voltage value of the second voltage detector 123, and in order to prevent overcharging, It was necessary to set the charging control voltage value by power regeneration to be relatively low. As a result, the charging current is as shown by a curve 72 (see FIG. 6), leading to a decrease in regeneration efficiency and a reduction in the chargeable range.

  However, in the discharge / regeneration control system according to the present embodiment, the detection voltage of the second voltage detector 23 is based on the detection result of the first voltage detector 13 and the detection result of the second voltage detector 23. A correction amount ΔV for the value V2 is calculated, and the detection voltage value V2 is corrected using the correction amount ΔV. That is, the detected voltage value V2 is corrected in a direction to cancel the difference between the detected voltage value of the first voltage detector 13 and the detected voltage value of the second voltage detector 23, and based on the corrected corrected voltage value Vq. Thus, the discharge / regeneration control unit 26 controls the inverter 25 to perform power regeneration. For this reason, a 1st charge control voltage value can be set comparatively high, the improvement of regeneration efficiency and the expansion of the chargeable range are achieved.

((FIGS. 7 and 8; second power regeneration control method))
Next, the second power regeneration control method will be described with reference to FIGS. FIG. 7 is a diagram illustrating a charging current when the second power regeneration control method is used. In FIG. 7, the horizontal axis is time, and the vertical axis is charging current by power regeneration. FIG. 8 is a flowchart showing the operation of the second power regeneration control method.

  The discharge / regeneration control unit 26 has already acquired information for calculating the correction amount ΔV before the start of power regeneration. Further, assuming that the secondary battery 11 is configured by connecting three lithium ion battery cells in series, and that the upper limit voltage of each cell is 4.2 V, the second power regeneration control method will be described. Do.

  First, immediately before power regeneration, the voltage between both electrodes (open voltage) of the secondary battery 11 at the time of no load is acquired (step S1). The open circuit voltage is a total voltage value of each cell of the secondary battery 11 calculated based on the detection result of the first voltage detector 13. The process of step S1 is performed at the time indicated in the above-described “specific example (c) or (d) at no load”.

  Then, the remaining amount (initial remaining amount) of the secondary battery 11 in step S1 is estimated from the open circuit voltage (step S2). The remaining capacity of the secondary battery 11 in step S1 is (capacity that can be output from the secondary battery 11 in step S1) / (output when each cell constituting the secondary battery 11 is fully charged) Capacity). For example, the discharge / regeneration control device 2 is provided with a memory (not shown) for storing table data for estimating the remaining amount from the open circuit voltage, and the discharge / regeneration control unit 26 refers to the stored data in the memory. To estimate the remaining amount. For example, if the open circuit voltage calculated in step S1 is 11.2V, the remaining amount is estimated to be 50%. If the open circuit voltage calculated in step S1 is 4.2V × 3 = 12.6V, the remaining amount is 100%.

  In step S3, which is shifted to after step S2, the discharge / regeneration control unit 26 determines whether or not the remaining amount (initial remaining amount) estimated in step S2 is larger than a predetermined first reference capacity. . The first reference capacity can be set to an arbitrary value, but is preferably a capacity close to full charge. For example, the remaining amount of 90 to 95% is set to be equal to the first reference capacity.

  If the initial remaining capacity is larger than the first reference capacity, the process proceeds to step S9 described later (Y in step S3), but if smaller, the process proceeds to step S4, and the variable k indicating the remaining amount increase is initialized to zero. Turn into.

Subsequently, in step S5, the charge control voltage value related to power regeneration is set to the first charge control voltage value, and then power regeneration is performed (started) in step S6. That is, the discharge / regeneration control unit 26 controls the inverter 25 so that the correction voltage value Vq matches the charge control voltage value (that is, the first charge control voltage value) (step-up chopper as shown in FIG. 3). Configure). At this time, if the charge current does not exceed the upper limit current I _L, the correction voltage value Vq is power regeneration is performed by sustained by constant voltage to match the first charge control voltage value, the charging current limit When the current I _L is reached, power regeneration is performed in a state where the charging current matches the upper limit current I _L (that is, at a constant current). That is, the discharge / regeneration controller 26, under the condition that the charging current does not exceed the upper limit current I _L, the difference between the corrected voltage value Vq and charge control voltage value (i.e., the first charge control voltage value) The inverter 25 is controlled so as to be small (approaching zero). Note that the correction voltage value Vq is equal to or lower than the first charge control voltage value during a period in which power regeneration is performed at a constant current.

  The first charge control voltage value is determined according to the number of cells constituting the secondary battery 11 and the type of the secondary battery 11. When the secondary battery 11 is configured by connecting three lithium ion battery cells in series, the first charge control voltage value is, for example, 4.2 V (upper limit voltage per cell) × 3 = 12. 6V. The discharge / regeneration control unit 26 regards the detected current value detected by the second current detector 22 as a charging current by power regeneration. FIG. 7 shows an example in which charging is performed at a constant current in the initial stage of charging.

  When power regeneration is started, an increase in the remaining amount due to power regeneration is calculated in step S7. Since the amount of increase in the remaining amount and the amount of charging current for the secondary battery 11 are correlated, the discharge / regeneration control unit 26 acquires the detection results of the second current detector 22 one after another at a predetermined timing. Thus, the discharge / regeneration control unit 26 can calculate the amount of increase in the remaining amount from step S6 to step S7. Further, the increase amount of the remaining amount calculated in step S7 is simultaneously added to the variable k.

  Further, the battery-side control unit 14 acquires the detection results of the first current detector 12 one after another at a predetermined timing, and transmits the detection results (or information based on the detection results) to the discharge / regeneration control unit 26. It may be. Furthermore, the battery unit 1 is provided with a fuel gauge (not shown) for measuring the remaining amount of the secondary battery 11, and the measurement result of the fuel gauge is discharged / regenerated via the battery side control unit 14. You may make it transmit to the control part 26. FIG. Also by these methods, the amount of increase in the remaining amount can be calculated. The fuel gauge is arranged in series on a line connecting the positive electrode 11a of the secondary battery 11 and the input / output terminal 15a, for example. Since the configuration of the fuel gauge is the same as a well-known one, detailed description of the configuration is omitted, but for example, the fuel gauge is self-assembling one after another at regular intervals (for example, 100 milliseconds). Information about the amount of current that has passed (this amount of current is equal to the amount of current flowing through the secondary battery 11) is transmitted to the battery-side control unit 14.

  In step S8 where the process of step S7 shifts, the sum of the initial remaining amount estimated in step S2 and the value of the variable k (remaining amount increase) calculated in step S7 is larger than the first reference capacity. It is determined whether or not. If the sum is equal to or less than the first reference capacity (N in Step S8), the process returns to Step S6 described above, and power regeneration is continued with the charge control voltage value as the first charge control voltage value. However, when the sum is larger than the first reference capacity (Y in step S8), the process proceeds to step S9 described later.

  In step S9, the charge control voltage value related to power regeneration is set as the second charge control voltage value. Similar to the first charge control voltage value, the second charge control voltage value is determined according to the number of cells constituting the secondary battery 11 and the type of the secondary battery 11, but the first charge control voltage Set lower than the value. When the secondary battery 11 is configured by connecting three lithium ion battery cells in series, the second charge control voltage value is, for example, 4.0 V × 3 = 12.0 V.

  After the process of step S9, power regeneration is continued (step S10). That is, the discharge / regeneration control unit 26 controls the inverter 25 so that the difference between the correction voltage value Vq and the charge control voltage value (that is, the second charge control voltage value) is small (approaching zero). (A boost chopper as shown in FIG. 3 is configured). For this reason, the curve of the charging current by power regeneration (see FIG. 7) is changed from the curve 74 (4.2 V per cell) corresponding to the first charge control voltage value to the curve 75 corresponding to the second charge control voltage value. (4.0V per cell). When the determination result in step S8 is affirmative (Y in step S8), the secondary battery 11 is charged with a constant voltage (in other words, the first reference capacity and the The first charge control voltage value is set).

  In step S11 subsequent to step S10, the increase amount of the remaining amount due to power regeneration is calculated, and the increase amount is added to the variable k, as in the process of step S7. Subsequently, in step S12, it is determined whether the sum of the initial remaining amount estimated in step S2 and the value of the variable k (remaining amount increase) calculated in step S11 has reached a predetermined charge stop capacity. The When the sum is less than the charge stop capacity (N in Step S12), the process returns to Step S10 described above, and power regeneration is continued with the charge control voltage value as the second charge control voltage value. When the sum reaches the first charge stop capacity (Y in step S12), the power regeneration is terminated.

Further, instead of the process of the steps S11 and S12, drives out establishment of the condition that descends until the charging current reaches a charging stop current I _F, may be stopped charging by power regeneration. As understood from the above description, the discharge / regeneration control unit 26, or the battery side control unit 14 and the discharge / regeneration control unit 26 are used as remaining amount estimating means for estimating the remaining amount of the secondary battery 11. It has the function of.

As described above, by reducing the charge control voltage value related to power regeneration, for example, at a stage close to full charge, the safety of power regeneration is enhanced, and the risk of deterioration or damage of the secondary battery 11 due to power regeneration is increased. It can be further reduced. Although an upper limit current I _L is provided for the charging current and power regeneration is performed at a constant voltage, a large pulsed current can flow into the secondary battery 11 and charging near the upper limit voltage (for safety) In view of the burden on the secondary battery 11 due to charging with a small margin), it is preferable to adopt the second power regeneration control method rather than the first power regeneration control method.

((FIG. 9, FIG. 10; modified method 1 of the second power regeneration control method))
Further, the second power regeneration control method can be modified as follows. This modified method (hereinafter referred to as “deformed method 1”) will be described with reference to FIGS. 9 and 10. FIG. 9 is a diagram illustrating a charging current when the deformation method 1 is used. In FIG. 9, the horizontal axis is time, and the vertical axis is charging current by power regeneration. FIG. 10 is a flowchart for explaining the operation of the deformation method 1.

  The operation of the deformation method 1 includes steps S1 to S11 and steps S20 to S24. This operation is similar to the operation of the second power regeneration control method shown in FIG. 8. When the determination result in step S3 is affirmative (initial remaining amount> first reference capacity is established), in step S9, The operations of Steps S <b> 1 to S <b> 11 (FIG. 8) in the deformation method 1 are the same as the operations of the second power regeneration control method that is not deformed except that the process proceeds to Step S <b> 20 described later. FIG. 10 illustrates only the operation around the deformed portion by the deforming method 1. However, the second charge control voltage value (<first charge control voltage value) is set to 4.1 V × 3 = 12.3 V, for example, because a third charge control voltage value described later is provided.

  In the deformation method 1, after passing through S11 via steps S1 to S10, or after the determination result in step S3 becomes affirmative, the process proceeds to step S20. In step S20, a predetermined second reference whose sum of the initial remaining amount estimated in step S2 and the value of variable k (remaining amount increase) calculated in step S11 is larger than the first reference capacity. It is determined whether it is larger than the capacity. When the sum is equal to or less than the second reference capacity (N in Step S20), the process proceeds to Step S10 via Step S9 described above, and the power regeneration is performed with the charge control voltage value as the second charge control voltage value. If the sum reaches the second reference capacity (Y in step S20), the process proceeds to step S21.

  In step S21, the charge control voltage value related to power regeneration is set as the third charge control voltage value. Similar to the first and second charge control voltage values, the third charge control voltage value is determined according to the number of cells constituting the secondary battery 11 and the type of the secondary battery 11. It is set lower than the charge control voltage value. When the secondary battery 11 is configured by connecting three lithium ion battery cells in series, the third charge control voltage value is, for example, 4.0 V × 3 = 12.0 V (as described above, The second charge control voltage value in the modification method 1 is, for example, 4.1 V × 3 = 12.3 V).

  After the process of step S21, power regeneration is continued (step S22). That is, the discharge / regeneration control unit 26 controls the inverter 25 so that the difference between the correction voltage value Vq and the charge control voltage value (that is, the third charge control voltage value) becomes small (approaching zero). (A boost chopper as shown in FIG. 3 is configured). For this reason, the curve of the charging current by power regeneration (see FIG. 9) changes from a curve 77 corresponding to the second charge control voltage value to a curve 78 corresponding to the third charge control voltage value. A curve 76 is a curve of the charging current corresponding to the first charging control voltage value.

  In step S23 following step S22, the increase amount of the remaining amount due to power regeneration is calculated, and the increase amount is added to the variable k, as in the process of step S7. Subsequently, in step S24, it is determined whether the sum of the initial remaining amount estimated in step S2 and the value of the variable k (remaining amount increase) calculated in step S23 has reached a predetermined charge stop capacity. The When the sum is less than the charge stop capacity (N in Step S24), the process returns to Step S22 described above, and power regeneration is continued with the charge control voltage value as the third charge control voltage value. When the sum reaches the first charge stop capacity (Y in step S24), the power regeneration is terminated.

Further, instead of the process of the steps S23 and S24, drives out establishment of the condition that descends until the charging current reaches a charging stop current I _F, may be stopped charging by power regeneration.

  Also by this modification method 1, since the charge control voltage value related to power regeneration becomes low, for example, at a stage close to full charge, the same effect as that of the second power regeneration control method that does not deform can be obtained. Moreover, although the braking force in the moving body changes according to the amount of regenerative current (charging current to the secondary battery 11 during power regeneration), the regenerative current changes by gradually reducing the charging control voltage value. Therefore, the ride comfort of the moving body to which the discharge / regeneration control system according to this embodiment is applied is improved.

  Although the example in which the charge control voltage value is changed in three stages (first, second, and third charge control voltage values) has been shown, of course, the charge control voltage value may be changed in any plurality of stages.

((FIG. 11: Modified method 2 of the second power regeneration control method))
Further, the second power regeneration control method can be modified as follows. This modified method (hereinafter referred to as “deformed method 2”) will be described with reference to FIG. FIG. 11 is a diagram illustrating a charging current when the modification method 2 is used. In FIG. 11, the horizontal axis represents time, and the vertical axis represents charging current due to power regeneration. The operation in the deformation method 2 is similar to the operation of the second power regeneration control method that is not deformed (that is, the operation shown in FIG. 8), and only the different parts will be described with reference to FIG.

  In the second power regeneration control method that does not deform, when the determination result in step S8 is affirmative (Y in step S8) and the process proceeds to step S9, the charge control voltage value is changed from the first charge control voltage value to the second value. The charge control voltage value is changed. Then, the discharge / regeneration control unit 26 reduces the difference between the correction voltage value Vq and the first charge control voltage value (maintains the correction voltage value Vq at the first charge control voltage value) to the correction voltage. Immediate transition is made to a state where the difference between the value Vq and the second charge control voltage value is reduced (the correction voltage value Vq is maintained at the second charge control voltage value).

  When the operation of the step-up chopper as shown in FIG. 3 is considered as an example, the duty ratio for turning on the MOS transistor Tr1 is quickly shifted from 50% to 30%, for example. This transition is performed between several microseconds to several milliseconds, for example.

  Also in the modification method 2, when the determination result in step S8 is affirmative (Y in step S8) and the process proceeds to step S9, the charge control voltage value is changed from the first charge control voltage value to the second charge control voltage value. Is done. However, during this change, the discharge / regeneration control unit 26 reduces the difference between the correction voltage value Vq and the first charge control voltage value (maintains the correction voltage value Vq at the first charge control voltage value). The state is gradually shifted from the state to a state where the difference between the correction voltage value Vq and the second charge control voltage value is reduced (the correction voltage value Vq is maintained at the second charge control voltage value).

  In order to make this transition gradually, for example, when the operation of the step-up chopper as shown in FIG. 3 is considered as an example, the duty ratio for turning on the MOS transistor Tr1 is limited to the amount of change per unit time (upper limit). ). For example, if the upper limit of the amount of change per 100 milliseconds is 2%, the duty ratio gradually decreases, and it takes at least 1 second for the duty ratio to decrease from 50% to 30%.

  By performing such control, the charging current due to power regeneration changes smoothly as shown in FIG. This deformation method 2 can be combined with the above deformation method 1. For example, in the modification method 1, when the charge control voltage value is changed from the second charge control voltage value to the third charge control voltage value, the difference between the correction voltage value Vq and the second charge control voltage value is reduced. The difference between the correction voltage value Vq and the third charge control voltage value is reduced from the state where the correction voltage value Vq is maintained at the second charge control voltage value (the correction voltage value Vq is the third charge control). It may be possible to gradually shift to a state where the voltage value is maintained.

  Also with this modification method 2, since the charge control voltage value related to power regeneration becomes low, for example, at a stage close to full charge, the same effect as that of the second power regeneration control technique without deformation can be obtained. Moreover, although the braking force in the moving body changes according to the amount of regenerative current (charging current to the secondary battery 11 during power regeneration), the transition of the state as described above is performed, Since the change of the regenerative current becomes smooth, the riding comfort of the moving body to which the discharge / regeneration control system according to the present embodiment is applied is improved.

<< Other, deformation, etc. >>
Further, when the power regeneration is performed again after the operation shown in FIG. 8 or FIG. 10 has been performed to the end or halfway, steps S1 and S2 can be omitted (of course, not omitted and performed from step S1. It does not matter.) In this case, for example, the initial remaining amount estimated in step S2 at the previous power regeneration, the value of the final variable k (remaining amount increase) at the previous power regeneration, and the current power regeneration end time this time The sum of the amount of change in the remaining amount corresponding to the current integrated value (the integrated value of the current flowing through the secondary battery 11) up to the time point of starting the power regeneration may be used as the initial remaining amount at the time of the current power regeneration.

  By obtaining the detection results of the first current detector 12 one after another or by obtaining the detection results of the second current detector 22 one after another, the discharge / regeneration control unit 26 calculates the integrated current value. At this time, for example, the current integration may be performed with the direction of the current flowing out from the secondary battery 11 being positive and the direction of the current flowing into the secondary battery 11 being negative. In addition, when the battery unit 1 is provided with the fuel gauge, instead of performing current integration to obtain the remaining amount change amount, obtain the remaining amount change amount based on the measurement result of the remaining amount meter. Also good.

(Use the detection result of the first voltage detector as it is)
In addition, the power regeneration control using the correction voltage value Vq as described above is not performed, but the detection results of the first voltage detector 13 are sequentially supplied to the discharge / regeneration control unit via the battery side control unit 14. A method of performing power regeneration control (without using the detection result of the second voltage detector 23) based on the detection result of the first voltage detector 13 that is transmitted to the transmitter 26 and sent one after another is also conceivable. . This is because the influence of the difference in detection error existing between the first voltage detector 13 and the second voltage detector 23 can also be eliminated by this method.

  However, such a system has several problems. Therefore, power regeneration control using the correction voltage value Vq as described above is more desirable.

  First, interrupt requests to the discharge / regeneration control unit 26 are frequently generated, and the time allocated to other operations is reduced. In order to maintain the voltage applied to the secondary battery 11 at a desired voltage so as to ensure the safety of the secondary battery 11 during power regeneration, the voltage applied to the secondary battery 11 is set to, for example, several microseconds to several millimeters. It is necessary to obtain the data every second and sequentially control the inverter 25 based on the obtained voltage. In the case of adopting the above method, in order to meet such a need, the voltage applied to the secondary battery 11 is acquired every few microseconds to several milliseconds by the first voltage detector 13, and the acquired The value needs to be transmitted to the discharge / regeneration control unit 26 via the battery side control unit 14 every several microseconds to several milliseconds. Each time the transmission is performed, the discharge / regeneration control unit 26 needs to execute a process related to the transmission. That is, since the discharge / regeneration control unit 26 needs to respond to an interrupt request from the battery-side control unit 14 every several microseconds to several milliseconds, the above-described problem occurs.

  Second, if information needs to be transmitted at high speed, it is vulnerable to noise. As already illustrated, the discharge / regeneration control device 2 is disposed near the front wheel of the two-wheeled vehicle, but the battery unit 1 may be disposed only on the rear wheel portion of the two-wheeled vehicle due to space constraints. In such a case, the problem of being particularly vulnerable to noise can be significant.

  Third, if it is necessary to transmit information at a high speed, it is necessary to use a high-speed microcomputer or the like, which causes an increase in cost and power consumption. Also, since it is desirable to reduce the number of wires connecting the battery unit 1 and the discharge / regeneration control device 2 as much as possible, it is not possible to transmit voltage data in parallel for the purpose of reducing the transmission speed. It is hard to adopt.

  The present invention can be applied to any device as long as it is a device that charges a secondary battery with regenerative power in addition to a moving body such as an automobile (electric vehicle) or a motorcycle (so-called motorcycle or electric bicycle) driven by a motor or the like. Applicable.

It is a block block diagram of the discharge / regeneration control system to which this invention is applied. It is a figure which shows the detail of a structure of the inverter of FIG. It is a figure for demonstrating that the inverter of FIG. 2 operate | moves as a pressure | voltage rise chopper at the time of electric power regeneration. It is a figure for demonstrating the 1st correction amount calculation method. It is a figure for demonstrating the 2nd correction amount calculation method. It is a figure for demonstrating the 1st electric power regeneration control method. It is a figure for demonstrating the 2nd electric power regeneration control method. It is a flowchart for demonstrating operation | movement of the 2nd electric power regeneration control method. It is a figure for demonstrating the modification of the 2nd electric power regeneration control method. It is a flowchart for demonstrating operation | movement of the modification of a 2nd electric power regeneration control method. It is a figure for demonstrating the other modification of the 2nd electric power regeneration control method. It is a block block diagram of the conventional discharge / regeneration control system. It is a figure for demonstrating the charging current in the case of charging the secondary battery of FIG. 12 with a charger. It is a figure for demonstrating the charging current in the case of charging the secondary battery of FIG. 12 by electric power regeneration.

Explanation of symbols

1 Battery unit 2 Discharge / regenerative control device (regenerative control device)
DESCRIPTION OF SYMBOLS 11 Secondary battery 11a Positive electrode 11b Negative electrode 12 1st current detector 13 1st voltage detector 14 Battery side control part 15a, 15b Input / output terminal (unit side input / output terminal)
21a, 21b Input / output terminal 22 Second current detector 23 Second voltage detector 24 Motor 25 Inverter 25a Positive voltage side terminal 25b Negative voltage side terminal 26 Discharge / regeneration control unit

Tr1, Tr2, Tr3, Tr4, Tr5, Tr6 MOS transistors D1, D2, D3, D4, D5, D6 Parasitic diodes Lu, Lv, Lw Armature winding

Claims (3)

It consists of a battery unit and regenerative control equipment,
The battery unit is
A secondary battery, first voltage detection means for detecting the voltage of the secondary battery, and a pair of unit side input / output terminals connected to both electrodes of the secondary battery,
Regenerative control equipment
A pair of input / output terminals to be connected to the pair of unit side input / output terminals;
Power conversion means connected to the pair of input / output terminals and for converting the driving force of the load into the charging power of the secondary battery at the time of power regeneration from the load;
Second voltage detection means for detecting a voltage applied to the power conversion means;
A regenerative control system comprising: a control unit that controls the power regeneration by the power conversion unit based on a detection result of the second voltage detection unit;
The control means includes a detection result of the first voltage detection means and a detection result of the second voltage detection means at a predetermined timing when there is no load in which a current flowing through the secondary battery and the power converter is zero. The correction amount for the detection voltage value of the second voltage detection unit is calculated based on the correction voltage value, and the power based on the correction voltage value obtained by correcting the detection voltage value of the second voltage detection unit using the correction amount. It has line control of the regeneration,
The secondary battery is composed of n (n is an integer of 2 or more) cells connected in series,
The first voltage detection means can individually detect the voltage value of each cell;
The control means is based on a difference value between a voltage value obtained by multiplying the maximum voltage value of the voltage value of each cell at the predetermined timing at the time of no load by the n and a detection voltage value of the second voltage detection means. A regenerative control system characterized in that the correction amount is calculated . It consists of a battery unit and regenerative control equipment,
The battery unit is
A secondary battery, first voltage detection means for detecting the voltage of the secondary battery, and a pair of unit side input / output terminals connected to both electrodes of the secondary battery,
Regenerative control equipment
A pair of input / output terminals to be connected to the pair of unit side input / output terminals;
Power conversion means connected to the pair of input / output terminals and for converting the driving force of the load into the charging power of the secondary battery at the time of power regeneration from the load;
Second voltage detection means for detecting a voltage applied to the power conversion means;
A regenerative control system comprising: a control unit that controls the power regeneration by the power conversion unit based on a detection result of the second voltage detection unit;
The control means includes a detection result of the first voltage detection means and a detection result of the second voltage detection means at a predetermined timing when there is no load in which a current flowing through the secondary battery and the power converter is zero. The correction amount for the detection voltage value of the second voltage detection unit is calculated based on the correction voltage value, and the power based on the correction voltage value obtained by correcting the detection voltage value of the second voltage detection unit using the correction amount. Control regeneration,
The secondary battery is composed of n (n is an integer of 2 or more) cells connected in series,
The first voltage detection means can individually detect the voltage value of each cell;
Wherein, in each of the plurality of timing in different said no-load the total voltage value of each cell to each other, the voltage value and the second voltage detection multiplied by the n to the maximum voltage value of the voltage value of each cell The detection voltage value of the means is acquired, and the correction amount is calculated as an amount that changes according to the detection voltage value of the second voltage detection means based on the acquired value. system. A regenerative control device that can connect a battery unit with a secondary battery.
A pair of input / output terminals to be connected to both electrodes of the secondary battery via the input / output terminals on the battery unit side;
Power conversion means connected to the pair of input / output terminals and for converting the driving force of the load into the charging power of the secondary battery at the time of power regeneration from the load;
Second voltage detection means for detecting a voltage applied to the power conversion means;
In a regenerative control device comprising: control means for controlling the power regeneration by the power conversion means based on the detection result of the second voltage detection means,
The control means includes the second voltage and the information about the voltage of the secondary battery at a predetermined timing when there is no load when the current flowing through the secondary battery and the power conversion device transmitted from the battery unit is zero. A correction voltage value obtained by calculating a correction amount for the detection voltage value of the second voltage detection unit based on the detection result of the detection unit, and correcting the detection voltage value of the second voltage detection unit using the correction amount. There line control of the power regeneration based on,
The secondary battery is composed of n (n is an integer of 2 or more) cells connected in series,
The information on the voltage of the secondary battery is information based on the voltage value of each cell,
The control means is based on a difference value between a voltage value obtained by multiplying the maximum voltage value of the voltage value of each cell at the predetermined timing at the time of no load by the n and a detection voltage value of the second voltage detection means. A regenerative control device that calculates the correction amount .

Images