Storage battery temperature rise control device and storage battery temperature rise system

Abstract

A storage battery temperature-increasing control device (10) for increasing the temperature of a storage battery (1) by passing current through the storage battery (1) has: a positive direction current mode in which a positive direction current which is an intermittent pulsed current in a direction into the storage battery (1) is passed; a negative direction current mode in which a negative direction current which is an intermittent pulsed current in a direction out of the storage battery (1) is passed; and a bi-direction current mode in which a bi-direction current comprising one pulse of the positive direction current and one pulse of the negative direction current that flow alternately is passed. The storage battery temperature-increasing control device (10) performs control such that, when current is passed through the storage battery (1), one of the positive direction current mode, the negative direction current mode, and the bi-direction current mode that produces the largest amount of heat generated from the storage battery (1) is selected in accordance with the temperature of the storage battery (1) and the voltage of the storage battery (1).

Description

[Technical field]

[0001] The present application relates to a temperature rise control device for a storage battery and a temperature rise system for a storage battery. [Background technology]

[0002] In recent years, electric vehicles such as electric cars and hybrid electric cars have been put to practical use in order to reduce the environmental load. Stationary storage battery systems for utilizing renewable energy have also become widespread. These devices use storage batteries such as lithium-ion batteries. It is well known that when the temperature of a storage battery decreases, the internal resistance increases and the input / output characteristics decrease. Therefore, there is a technology that heats the battery from the inside by Joule heat by passing a ripple current through the storage battery, thereby raising its temperature.

[0003] For example, Patent Document 1 describes an energy storage system that, by providing a reactor with a different inductance in addition to the reactor that is normally used, increases the amplitude of the ripple current, increases the amount of heat generated by the storage battery, and efficiently warms up the storage battery. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2014-087081 A Summary of the Invention [Problem to be solved by the invention]

[0005] Generally, from the viewpoint of safety and durability, it is required that the upper and lower limit voltages of the storage battery be observed. However, when the temperature of the storage battery is raised by the ripple current, if the storage battery is in a fully charged state and the voltage of the storage battery is close to the upper limit voltage, or if the storage battery is in a fully discharged state and the voltage of the storage battery is close to the lower limit voltage, it may be impossible to pass a sufficient ripple current to the storage battery to raise the temperature so as not to exceed the upper and lower limit voltages.

[0006] The present application has been made to solve the above-mentioned problems, and aims to provide a storage battery heating control device and a storage battery heating system that can pass a sufficient current required for heating the storage battery even when the battery is fully charged or fully discharged, and can quickly heat the storage battery. [Means for solving the problem]

[0007] The temperature rise control device for a storage battery disclosed in the present application is a temperature rise control device for a storage battery for raising the temperature of the storage battery by passing a current through the storage battery, and has a positive current mode in which a positive current that is an intermittent pulse current flowing into the storage battery passes, a negative current mode in which a negative current that is an intermittent pulse current flowing out of the storage battery passes, and a bidirectional current mode in which a bidirectional current passes in which one pulse of the positive current and one pulse of the negative current alternately passes, and controls the current to pass through the storage battery by selecting one of the positive current mode, the negative current mode, and the bidirectional current mode that generates the greatest amount of heat from the storage battery in response to the temperature and voltage of the storage battery.

[0008] The present application also discloses a storage battery heating system, which is a storage battery heating system that heats up the storage battery by passing a current through the storage battery, and which is connected to the storage battery and passes a current through the storage battery in at least one of a positive current mode in which a positive current that is an intermittent pulse current flowing into the storage battery passes, a negative current mode in which a negative current that is an intermittent pulse current flowing out of the storage battery passes, and a bidirectional current mode in which a bidirectional current in which one pulse of the positive current and one pulse of the negative current flow alternately passes. The storage battery temperature rise control device includes one or more devices that can control a current flow in the positive current mode, the negative current mode, and the bidirectional current mode to flow through the storage battery by using the one or more devices, and further includes a storage battery temperature rise control device that controls the one or more devices to select, in response to a temperature of the storage battery and a voltage of the storage battery, a current mode that generates the largest amount of heat from the storage battery out of the positive current mode, the negative current mode, and the bidirectional current mode, and flows a current through the storage battery. Effect of the Invention

[0009] According to the present application, it is possible to provide a storage battery temperature rise control device and a storage battery temperature rise system that can quickly raise the temperature of a storage battery even when the storage battery is in a fully charged or fully discharged state. [Brief description of the drawings]

[0010] [Figure 1] 1 is a block diagram showing a configuration of a temperature rise control device for a storage battery in accordance with a first embodiment. [Diagram 2] 3 is a block diagram showing a configuration of a storage battery information acquisition unit of the storage battery temperature rise control device in accordance with the first embodiment. FIG. [Diagram 3] 3 is a block diagram showing an internal configuration of a charge / discharge circuit controller of the temperature rise control device for the storage battery in accordance with the first embodiment. FIG. [Figure 4] 4 is a flowchart showing the processing in a heat generation amount calculation unit of the temperature rise control device for a storage battery in accordance with the first embodiment. [Diagram 5]4 is a diagram illustrating the operation of the storage battery temperature rise control device in the first embodiment in a forward current mode. FIG. [Figure 6] 4 is a diagram illustrating the operation of the battery temperature rise control device in accordance with the first embodiment in a negative current mode. FIG. [Figure 7] 4 is a diagram illustrating the operation of the storage battery temperature rise control device in a bidirectional current mode according to the first embodiment. FIG. [Figure 8] FIG. 4 is a diagram showing an example of frequency characteristics of impedance of a storage battery. [Figure 9] FIG. 2 is a diagram showing an example of a Nyquist plot of a storage battery. [Figure 10] FIG. 1 is a circuit diagram showing an example of an equivalent circuit model of a general storage battery. [Figure 11] 13 is a diagram showing a current waveform in a bidirectional current mode of a temperature rise control device for a storage battery according to a second embodiment. FIG. [Figure 12] FIG. 11 is a block diagram showing the configuration of a charge / discharge circuit controller of a temperature rise control device for a storage battery according to a fourth embodiment. [Figure 13] FIG. 13 is a block diagram showing the configuration of a heating system for a storage battery according to a fifth embodiment. [Figure 14] FIG. 2 is a block diagram showing an example of a hardware configuration of a charge / discharge circuit controller according to the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Embodiment 1 Fig. 1 is a block diagram showing the configuration of a temperature rise control device 10 for a storage battery according to embodiment 1. As shown in Fig. 1, the temperature rise control device for a storage battery includes a storage battery information acquisition unit 2, a charge / discharge circuit controller 3, and a charge / discharge circuit 4 that generates a current including a frequency component.

[0012] The storage battery 1 to be heated is composed of a secondary battery such as a lithium ion battery or a nickel metal hydride battery. The shape of the secondary battery applied to this embodiment may be various shapes such as a cylindrical type, a rectangular type, a laminated type, etc. The storage battery 1 may be a battery pack in which a plurality of storage batteries having the same specifications, such as the same rated voltage, are connected in series or parallel, or in series-parallel.

[0013] Fig. 2 is a block diagram showing the configuration of the storage battery information acquisition unit 2. As shown in Fig. 2, the storage battery information acquisition unit 2 is composed of a voltage measurement unit 21, a current measurement unit 22, a temperature measurement unit 23, and an output unit 24. The voltage measurement unit 21 is composed of a voltage sensor that measures the voltage of the storage battery 1. The current measurement unit 22 is composed of a current sensor that measures the current flowing through the storage battery 1. The temperature measurement unit 23 is composed of a temperature sensor using, for example, a thermistor, and measures the temperature of the storage battery 1. The measured voltage, current, and temperature of the storage battery 1 are converted by the output unit 24 into, for example, digital signals and output as data to the charge / discharge circuit controller 3.

[0014] FIG. 3 is a block diagram showing the internal configuration of the charge / discharge circuit controller 3. As shown in FIG. 3, the charge / discharge circuit controller 3 is composed of an input unit 31, a heat generation amount calculation unit 32, and an output unit 33. The input unit 31 receives data on the voltage, current, and temperature of the storage battery 1 output from the storage battery information acquisition unit 2. The heat generation amount calculation unit 32 calculates the heat generation amount of the storage battery 1 based on the data from the input unit 31. The heat generation amount calculation unit 32 selects a current mode with the highest heat generation amount from among a current waveform with only a positive direction (this is called a positive direction current mode), a current waveform with only a negative direction (this is called a negative direction current mode), and each current waveform with both directions (this is called a bidirectional current mode) based on the current voltage of the storage battery 1, and controls the charge / discharge circuit 4 via the output unit 33 to pass a current in the current mode with the highest heat generation amount to the storage battery 1, thereby raising the temperature of the storage battery.

[0015] Here, a method for heating the storage battery 1 in the first embodiment will be described. FIG. 4 is a diagram showing a flowchart during the heating operation of the storage battery 1. First, in step S1, the temperature T of the storage battery is measured. Next, in step S2, it is determined whether T is equal to or lower than a threshold T1 that requires heating processing of the storage battery. If T is higher than the threshold T1, the process proceeds to step S9, and the heating processing is not performed and the process ends. On the other hand, if the temperature of the storage battery is equal to or lower than the threshold T1 in step S2, the process proceeds to step S3.

[0016] In step S3, the voltage of the storage battery is measured. Then, in step S4, the difference between the voltage of the storage battery measured in S3 and the upper limit voltage and the lower limit voltage is calculated. Here, the upper limit voltage and the lower limit voltage of the storage battery are preset as the specifications of the storage battery. If the storage battery 1 is a battery pack in which multiple storage batteries with the same specifications such as rated voltage are connected, the upper limit voltage and the lower limit voltage of each storage battery are set from the upper limit voltage and the lower limit voltage of the battery pack and the number of storage batteries in series. In the next step S5, the heat generation amount of each storage battery is calculated when a current flows in a current waveform only in the positive direction (positive current mode), a current waveform only in the negative direction (negative current mode), and a current waveform in both directions (both directions) that flows alternately in the positive and negative directions, which are voltage fluctuations that fall within the upper and lower limit voltages. The heat generation amount is calculated by multiplying the square of the effective value of the current waveform by the internal resistance of the storage battery. In step S6, the current mode with the largest heat generation amount is selected, and in step S7, the charging / discharging circuit 4 passes a current to the storage battery 1 in the selected current mode. After a certain period of time has elapsed, in step S8, the temperature T of the storage battery is measured and it is determined whether it is above the temperature threshold T2 at which the heating process is terminated. If it is below T2, the heating process continues, and if it is above T2, the process proceeds to step S9 and the heating process is terminated.

[0017] Here, T1 is assumed to be an extremely low temperature, such as -20°C or lower, at which charging and discharging of the storage battery is prohibited, but since the performance of the storage battery decreases slightly even at low temperatures, it may be set to, for example, around 5°C. Also, T2 is assumed to be around room temperature (around 25°C), but it may be set to, for example, around 10°C in order to shorten the temperature rise time.

[0018] Next, the current waveform in step S5 will be described. FIG. 5 is a diagram showing an example of the current waveform in the positive current mode and the voltage fluctuation between the terminals of the storage battery. The voltage between the terminals of the storage battery when a current flows is the voltage of the storage battery plus the voltage drop caused by the impedance such as the internal resistance of the storage battery when a current flows. As shown in the waveform in the upper part of FIG. 5, the current waveform in the positive current mode is a current waveform of intermittent pulses in the positive direction. The lower part of FIG. 5 shows the voltage fluctuation of the storage battery when a current of the current waveform in the positive current mode shown in the upper part flows. Here, the current flowing into the storage battery is the positive current, and the current flowing out of the storage battery is the negative current. When the current in the positive current mode flows into the storage battery, the voltage of the storage battery fluctuates at a value higher than the current voltage Vt. At this time, the amplitude of the current is set to an amplitude limited by the upper limit voltage Vmax so that the voltage between the terminals of the storage battery does not exceed the upper limit voltage Vmax. Therefore, when a current in the forward current mode is passed so that the amplitude is the difference (Vmax-Vt) between the upper limit voltage Vmax and the current voltage Vt, the amount of heat generated by the battery becomes the largest and the time required for temperature rise becomes short. If the battery 1 is an assembled battery, there may be variation in the voltage of each battery in the assembled battery, so the same procedure is used to determine the voltage of the battery with the highest voltage so that it does not exceed the upper limit voltage of that battery. Here, it is assumed that the voltage of each battery in the assembled battery can be detected.

[0019] FIG. 6 is a diagram showing an example of a current waveform in a negative current mode and a voltage fluctuation between the terminals of a storage battery. As shown in the upper part of FIG. 6, the current waveform in the negative current mode is a current waveform of intermittent pulses in the negative direction. The lower part of FIG. 6 shows the voltage fluctuation of the storage battery when a current of the current waveform in the negative current mode in the upper part flows. When a current in the negative current mode flows, it fluctuates at a value lower than the current voltage Vt. At this time, the amplitude of the current is set to an amplitude limited by the lower limit voltage Vmin so that the voltage between the terminals of the storage battery does not exceed the lower limit voltage Vmin. Therefore, when a negative current flows so that the amplitude is the difference (Vt-Vmin) between the lower limit voltage Vmin and the current voltage Vt, the amount of heat generated by the storage battery becomes the largest and the temperature rise time becomes short. When the storage battery 1 is a battery pack, the voltage of the storage battery with the lowest voltage among the storage batteries in the battery pack is determined in a similar procedure so that it does not exceed the lower limit voltage of that storage battery.

[0020] FIG. 7 is a diagram showing an example of a current waveform in a bidirectional current mode and a voltage fluctuation between the terminals of a storage battery. In the case of a current waveform in a bidirectional current mode, the amplitude of the current is set to an amplitude limited by the upper limit voltage Vmax and the lower limit voltage Vmin so that the voltage between the terminals of the storage battery does not exceed the upper limit voltage Vmax and the lower limit voltage Vmin. Therefore, the current amplitude that is the smaller of Vmax-Vt, which is the difference between the current voltage Vt and the upper limit voltage Vmax, and Vt-Vmin, which is the difference between the lower limit voltage Vmin, becomes the maximum amplitude, and the temperature rise time is the shortest. Note that FIG. 7 shows a case where the voltage is limited to the upper limit voltage Vmax, but of course, there is also a case where the voltage is limited to the lower limit voltage Vmin. When the storage battery 1 is a battery pack, the voltages are determined in a similar procedure so that the voltage of the battery with the highest voltage does not exceed the upper limit voltage of the battery and the voltage of the battery with the lowest voltage does not exceed the lower limit voltage of the battery.

[0021] The heat generation amount calculation unit 32 calculates the heat generation amount (e.g., per unit time) when a current flows in a positive current mode, a negative current mode, and a bidirectional current mode from the current voltage Vt, using the resistance of the storage battery, and selects the current mode that provides the shortest heating time, i.e., the largest amount of heat generation. In addition, the current amplitude at this time does not need to be maximum, and any current amplitude that can be passed through the charging and discharging circuit used will suffice, and the current waveform may be a square wave, a sine wave, or any other wave without any particular restrictions.

[0022] In addition, at the stage where the voltage of the storage battery is measured in step S3, it is possible to select the current waveform of the positive current mode or the negative current mode. For example, when the voltage of the storage battery is higher than the median value between the upper limit voltage and the lower limit voltage, it is clear that the amplitude of the current waveform that can be passed through the storage battery is larger in the negative current mode than in the positive current mode. Conversely, when the voltage of the storage battery is lower than the median value between the upper limit voltage and the lower limit voltage, it is clear that the amplitude of the current waveform that can be passed through the storage battery is larger in the positive current mode than in the negative current mode. Therefore, after measuring the voltage of the storage battery in step S3, the positive current mode or the negative current mode is selected, and after calculating the difference between the upper and lower limit voltages in step S4, the heat generation amount in the positive current mode or the negative current mode selected according to the voltage and in the both-directional current mode is calculated in step S5.

[0023] Next, the frequency of the current waveform will be described. FIG. 8 is a diagram showing an example of the frequency characteristic of the impedance of a storage battery. As shown in FIG. 8, the impedance characteristic of a storage battery is smallest at around 1 kHz, and at frequencies higher than that, the impedance tends to increase as the frequency increases. In other words, the higher the current frequency, the more the storage battery generates heat, and the shorter the time required to heat up the storage battery. Therefore, it is desirable that the frequency of the current waveform is higher. Also, due to the characteristics of the storage battery, if the current is 1 kHz or less, the charge / discharge reaction proceeds. Therefore, since there is a possibility that charging / discharging may be performed outside the operating temperature range of the storage battery during the temperature rise process, it is desirable that the frequency of the current waveform is 1 kHz or more. Here, in the case of the positive current mode or negative current mode, it is the number of repetitions of the intermittent pulse per second, and in the case of the bidirectional current mode, it is the number of periods per second, with one positive and one negative pulse being one period. However, since each waveform contains harmonic frequency components, the heat generation amount may be calculated taking these into consideration.

[0024] As described above, if heating can only be performed using a ripple current in which current flows in both positive and negative directions as in the conventional method, when the storage battery is at the upper or lower limit voltage, the ripple current may instantaneously exceed the upper or lower limit voltage, which may affect the deterioration of the storage battery. Therefore, heating processing using a ripple current cannot be performed. However, according to this embodiment, the current mode that generates the greatest amount of heat is selected from the positive current mode, the negative current mode, and the bidirectional current mode according to the current voltage of the storage battery 1, and current is passed through the storage battery, thereby making it possible to heat the storage battery in a short time even when the storage battery is in a fully charged state where the voltage of the storage battery is close to the upper limit voltage, or in a fully discharged state where the voltage of the storage battery is close to the lower limit voltage.

[0025] Embodiment 2 Regarding the temperature rise control device for a storage battery according to the second embodiment, first, a current waveform in a positive current mode and a current waveform in a negative current mode will be described. FIG. 9 is a diagram showing an example of a Nyquist plot of a storage battery. Z' on the horizontal axis indicates the real component of the impedance of the storage battery, and Z" on the vertical axis indicates the imaginary component of the impedance of the storage battery. According to FIG. 9, the frequency of the semicircular part showing the charge and discharge reaction of the storage battery is generally in the range of 1 kHz to 1 Hz. This semicircle shows the charge and discharge reaction of the storage battery. FIG. 10 is a diagram showing an example of an equivalent circuit model of a general storage battery. The equivalent circuit model is composed of an open circuit voltage of the storage battery, a parasitic inductance L derived from the electrode structure of the storage battery and Rsol representing the resistance of the electrolyte and the current collecting foil, a parallel circuit of a resistor R1 and a capacitor C1 representing the charge and discharge reaction of the storage battery, and a resistor R2 and a capacitor C2 derived from the diffusion of ions. The equivalent circuit may be an equivalent circuit including a resistor R1 and a capacitor C1 representing the charge and discharge reaction of the storage battery, and other components may be represented by components other than the circuit of FIG. 10.

[0026] Among the components of the equivalent circuit shown in FIG. 10, the time constant τ of the charge / discharge reaction can be calculated from the product of R1 and C1, which indicate the charge / discharge of the storage battery. When a current waveform in a positive current mode or a negative current mode is applied as shown in FIG. 5 and FIG. 6, if the time during which no current is applied is short, charging and discharging to the electric double layer are performed without pause, and there is concern about the impact on deterioration of the storage battery. Therefore, by setting the pause time during which no current is applied to be equal to or greater than the above-mentioned time constant τ, it is possible to prevent charges from continuing to accumulate in the electric double layer. During the pause time, the charge / discharge reaction from the electric double layer to the positive electrode and the negative electrode progresses. However, as described in the first embodiment, since the frequency of the current waveform is set to 1 kHz or more, it is difficult to imagine that the charge state of the storage battery will change significantly, and there is no problem, considering that the charge amount flows in and out with a current waveform with a frequency of 1 kHz or more. Note that if the pause time is too long, the storage battery will radiate heat to the surrounding air and the temperature will drop, so the pause time at which the temperature does not drop will be the maximum.

[0027] Next, the current waveform in the bidirectional current mode will be described. FIG. 11 is a diagram showing an example of a current waveform in the bidirectional current mode. The current waveform in the bidirectional current mode shown in FIG. 7 is symmetrical in the positive direction and the negative direction. For example, this current waveform may be a current waveform such as a ripple current derived from a power converter. The current waveform in the bidirectional current mode may be asymmetrical in the positive direction and the negative direction, and may be any waveform as long as the current integral value in one pulse in the positive direction is equal to the current integral value in one pulse in the negative direction. The current waveform shown in FIG. 11 is a waveform that combines a waveform in which the amplitude in the positive direction is reduced and the time is extended accordingly, and a waveform in which the amplitude in the negative direction is increased and the time is shortened accordingly. In addition, a time in which no current flows between the positive direction and the negative direction may be provided. Note that, since an extremely low temperature in which the storage battery cannot be charged or discharged is assumed here, the waveform has the same current integral values ​​in the positive direction and the negative direction, but if the temperature is low enough to allow charging and discharging, the current integral values ​​in the positive direction and the negative direction do not necessarily need to be equal. In other words, a DC offset may be provided to the current waveform in both directions.

[0028] As described above, according to the second embodiment, in the current waveforms of the positive and negative current modes flowing through the storage battery, the pause time during which no current flows is set to be equal to or greater than the time constant of the charge / discharge reaction of the storage battery, thereby preventing the accumulation of charge in the electric double layer. This allows the current of the positive or negative current mode with an appropriate pause time to continue flowing through the storage battery, and the temperature of the storage battery can be raised without accumulating charge. In addition, by making the current waveform of the bidirectional current mode a waveform in which the current integral values ​​in the positive and negative directions, i.e., the amount of electricity, are equal, it is possible to raise the temperature without causing charging or discharging.

[0029] Third embodiment A third embodiment will be described. The temperature rise control device for a storage battery described in the first and second embodiments is capable of flowing a bidirectional current mode, that is, a ripple current, to the storage battery. In the third embodiment, a method of using this ripple current will be described. In the third embodiment, a minute ripple current is continuously flowed as a ripple current, which is a current waveform in a bidirectional current mode, to prevent the temperature from dropping to an extremely low temperature at which charging and discharging are not possible, and to control the temperature to always be kept at a predetermined temperature near room temperature. If the ripple current is a ripple current, the charges in the positive and negative directions are equal and no bias in the charges occurs, so there is no problem even if it flows through the storage battery for a long time. In addition, since it is within the operating temperature range, there is no limit to the frequency of the current. Here, if there is a difference between the upper limit voltage of the storage battery and the upper limit voltage during operation (upper limit voltage of the storage battery>upper limit voltage during operation), the ripple current can be continued to flow because the performance of the storage battery is not affected even if the upper limit voltage during operation is exceeded as long as the upper limit voltage of the storage battery is not exceeded. If there is no difference between the upper limit voltage of the storage battery and the upper limit voltage during operation, the storage battery may be discharged after operation to adjust the voltage so that the ripple current can flow.

[0030] As described above, according to the third embodiment, after the temperature of the storage battery rises to a predetermined temperature, a minute ripple current (current in a bidirectional current mode) whose current amplitude is equal to or less than a predetermined amplitude is continued to flow to keep the temperature of the storage battery within a predetermined temperature range, thereby making it possible to prevent a drop in the temperature of the storage battery and to prevent the storage battery from becoming extremely cold again.

[0031] Fourth embodiment FIG. 12 is a block diagram showing the configuration of the charge / discharge circuit controller 3 according to the fourth embodiment. The overall configuration of the temperature rise control device for a storage battery is the same as the configuration shown in FIG. 1. The configuration of the temperature rise control device for a storage battery according to the first embodiment is different in that the charge / discharge circuit controller 3 includes a usage history storage unit 5 and a usage prediction unit 6. The usage history storage unit 5 extracts and stores usage history mainly from measurement data of the current of the storage battery from the storage battery information acquisition unit 2. The usage history prediction unit 6 predicts the next time the storage battery will be used based on the usage history stored in the usage history storage unit. The charge / discharge circuit controller 3 controls the charge / discharge circuit 4 to heat the storage battery 1 in time for use based on the predicted next time the storage battery will be used.

[0032] As described above, according to the fourth embodiment, by predicting the next use time from the usage history, it is possible to complete the temperature increase process before the next use.

[0033] Fifth embodiment FIG. 13 is a block diagram showing the configuration of a storage battery heating system according to the fifth embodiment. The storage battery heating control device 100 constituting the heating system according to the fifth embodiment includes the storage battery information acquisition unit 2 and the charge / discharge circuit controller 3 described in the first embodiment. The charge / discharge circuit is divided into a charging circuit 41 and a discharging circuit 42 outside the storage battery heating control device 100, and further includes a balancer circuit 43. The storage battery is a battery pack 11 in which a plurality of storage batteries of the same specifications are connected in series and parallel. The charging circuit 41 may be any circuit that can charge the storage battery, and is mainly assumed to be an internal circuit of a charging device for charging the storage battery, including a converter. That is, the device 410 is a device 410 including the charging circuit 41. The discharge circuit 42 is a circuit including an inverter or a converter, and is assumed to operate a power conversion circuit of a power conversion device for supplying power to a load as the discharge circuit 42. That is, the device 420 is a device 420 including the discharge circuit 42. The balancer circuit 43 is a circuit for adjusting the voltage of the storage battery, and is used, for example, when a plurality of storage batteries are connected in series, to adjust the voltage of each storage battery, and is also provided in a device 430 external to the storage battery temperature rise control device 100. That is, the device 430 is a device 430 including a balancer circuit that adjusts the voltage of the storage battery. The balancer circuit 43 may be provided in a device 410 including a charging circuit or a device 420 including a discharging circuit. It is assumed that this balancer circuit will operate as a charging circuit or a discharging circuit.

[0034] The charge / discharge circuit controller 3 provided in the battery temperature rise control device 100 controls these external devices and controls the temperature rise of the battery provided in the battery pack 11 by passing a current in a positive current mode, a negative current mode, or a bidirectional current mode through the battery pack 11 in a manner similar to that described in the first to fourth embodiments.

[0035] In the configuration of the fifth embodiment, the current waveform in the positive current mode can be passed through the storage battery by current control in the charging circuit 41. The magnitude of the current waveform in the positive current mode is determined so that the voltage of the storage battery with the highest voltage among the storage batteries in the assembled battery 11 does not exceed the upper limit voltage of the storage battery. In the current waveform in the negative current mode, if the discharge circuit 42 is provided with a circuit capable of pulse discharge of the storage battery, the storage battery can be discharged with a current waveform in the negative current mode with an intermittent pulse of 1 kHz or more as described in the first embodiment. In the case where such a circuit is not provided, if the balancer circuit 43 is provided, it is possible to pass a current with a negative current mode current waveform through the storage battery by using the switching control of the balancer circuit 43. The balancer circuit 43 is preferably a passive type capable of only discharging the storage battery. The amplitude of the current waveform in the negative current mode is determined so that the voltage of the storage battery with the lowest voltage among the storage batteries in the assembled battery does not exceed the lower limit voltage of the storage battery. The current waveform in the bidirectional current mode can flow through the storage battery due to a ripple current or the like generated by switching of the power conversion circuit as a discharge circuit. The amplitude of the current waveform in the bidirectional current mode is determined so that the voltage of the storage battery with the highest voltage among the storage batteries in the battery pack does not exceed the upper limit voltage of that storage battery, and the voltage of the storage battery with the lowest voltage does not exceed the lower limit voltage of that storage battery.

[0036] In the above, the case where the storage battery is the assembled battery 11 has been described, but it goes without saying that the present invention can also be applied to a normal storage battery instead of the assembled battery.

[0037] As described above, the battery heating system according to embodiment 5 includes one or more devices (one or more of device 410, device 420, and device 430) that are connected to the storage battery and can pass a current in at least one of the positive current mode, negative current mode, and bidirectional current mode to the storage battery, and is configured to allow a current in the positive current mode, negative current mode, and bidirectional current mode to pass to the storage battery by using this one or more devices, and the battery heating control device 100 is configured to control the one or more devices to select the current mode from the positive current mode, negative current mode, and bidirectional current mode that generates the greatest amount of heat in the storage battery 11 and pass a current to the storage battery 11.

[0038] 13 shows a configuration in which all of the external charging circuit, discharging circuit, and balancer circuit are controlled to allow current in the positive current mode, current in the negative current mode, and current in the bidirectional current mode to flow through the battery pack 11, but it is not necessary to provide all of the circuits. Since a storage battery is generally left at a voltage close to a fully charged state, there is no problem even if the configuration does not allow current in the positive current mode to flow. Therefore, it is desirable to have a configuration that allows current in at least the negative current mode and bidirectional current mode to flow.

[0039] The storage battery heating system of this configuration includes one or more devices (one or more of device 410, device 420, and device 430) that are connected to the storage battery and can pass a current in at least one of the negative current mode and the bidirectional current mode to the storage battery, and is configured to allow a current in the negative current mode and the bidirectional current mode to pass to the storage battery by this one or more devices, and the storage battery heating control device 100 is configured to control the one or more devices to select the current mode between the negative current mode and the bidirectional current mode, whichever generates more heat from the storage battery, and pass a current to the storage battery 11.

[0040] Specifically, as shown in FIG. 14, the charge / discharge circuit controller 3 in each of the above embodiments includes a processor 301 such as a central processing unit (CPU), a storage device 302 that exchanges data with the processor 301, and an input / output interface 303 that inputs and outputs signals between the processor 301 and the outside. The processor 301 may include an application specific integrated circuit (ASIC), an integrated circuit (IC), a digital signal processor (DSP), a field programmable gate array (FPGA), and various signal processing circuits. The storage device 302 may include a random access memory (RAM) that is configured to read and write data from the processor 301, and a read only memory (ROM) that is configured to read data from the processor 301. The heat generation amount calculation unit 32 includes, for example, the processor 301 and the storage device 302 in which programs and data are stored. The input interface of the input / output interface 303 corresponds to, for example, the storage battery information acquisition unit 2, and the output interface is composed of a circuit for outputting a signal from the arithmetic processing device 301 to the charging / discharging circuit 4 or an external device described in embodiment 5.

[0041] Although various exemplary embodiments and examples are described in this application, various features, aspects, and functions described in one or more embodiments are not limited to the application of a specific embodiment, but can be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are expected within the scope of the technology disclosed in this specification. For example, the modification, addition, or omission of at least one component, and the extraction and combination of at least one component with components of other embodiments are included. [Explanation of symbols]

[0042] 1 storage battery, 2 storage battery information acquisition unit, 3 charge / discharge circuit controller, 4 charge / discharge circuit, 10, 100 storage battery temperature rise control device, 11 battery pack, 21 voltage measurement unit, 32 heat generation amount calculation unit, 41 charging circuit, 42 discharging circuit, 43 balancer circuit, 410 device including charging circuit, 420 device including discharging circuit, 430 device including balancer circuit, Vmax upper limit voltage, Vmin lower limit voltage

Claims

1. A temperature rise control device for a storage battery for raising the temperature of the storage battery by passing a current through the storage battery, A temperature rise control device for a battery having a positive current mode in which a positive current that is an intermittent pulse current flows in a direction flowing into the storage battery, a negative current mode in which a negative current that is an intermittent pulse current flows in a direction flowing out of the storage battery, and a bidirectional current mode in which a bidirectional current flows in which one pulse of the positive current and one pulse of the negative current flow alternately, and which controls the current to flow to the storage battery by selecting from the positive current mode, the negative current mode, and the bidirectional current mode which produces the largest amount of heat from the storage battery in response to a temperature of the storage battery and a voltage of the storage battery.

2. a charge / discharge circuit capable of outputting the positive current and the negative current to the storage battery, a voltage measurement unit that measures a voltage of the storage battery, and a heat generation amount calculation unit that calculates an amount of heat generated by the storage battery due to a current flowing through the storage battery, The heat generation amount calculation unit, with respect to the voltage of the storage battery from the voltage measurement unit, a heat generation amount of the storage battery in the forward current mode in which the storage battery is heated by the forward current in which the amplitude of the current is limited by a predetermined upper limit voltage of the storage battery; a heat generation amount of the storage battery in the negative current mode in which the storage battery is heated by the negative current whose amplitude is limited by a predetermined lower limit voltage of the storage battery; and a heat generation amount of the storage battery in the bidirectional current mode in which the storage battery is heated by the bidirectional current in which the amplitude of the current is limited by the upper limit voltage and the lower limit voltage; 2. The temperature rise control device for a storage battery according to claim 1, wherein the charge / discharge circuit outputs a current in a current mode in which the amount of heat generated is the greatest.

3. a charge / discharge circuit capable of outputting the positive current and the negative current to the storage battery, a voltage measurement unit that measures a voltage of the storage battery, and a heat generation amount calculation unit that calculates an amount of heat generated by the storage battery due to a current flowing through the storage battery, the heat generation amount calculation unit compares the voltage of the storage battery from the voltage measurement unit with a median between a predetermined upper limit voltage of the storage battery and a predetermined lower limit voltage of the storage battery; When the voltage of the storage battery is lower than the median value, a heat generation amount of the storage battery in the forward current mode in which the storage battery is heated by the forward current whose amplitude is limited by the upper limit voltage and a heat generation amount of the storage battery in the bidirectional current mode in which the storage battery is heated by the bidirectional current whose amplitude is limited by the upper limit voltage and the lower limit voltage are calculated, and the charging / discharging circuit outputs a current in the current mode which generates a larger amount of heat; 2. A battery temperature rise control device as described in claim 1, wherein, when the voltage of the storage battery is equal to or higher than the median, a heat generation amount of the storage battery in the negative current mode in which the storage battery is heated by the negative current whose amplitude is limited by the lower limit voltage, and a heat generation amount of the storage battery in the bidirectional current mode in which the storage battery is heated by the bidirectional current whose amplitude is limited by the upper limit voltage and the lower limit voltage are calculated, and the charge / discharge circuit outputs a current in the current mode which generates a greater amount of heat.

4. The temperature rise control device for a storage battery according to claim 1 , wherein the storage battery is a battery pack in which a plurality of storage batteries are connected in series and parallel.

5. The storage battery is a battery pack in which a plurality of storage batteries are connected in series and parallel, the heat generation amount calculation unit sets the predetermined upper limit voltage to an upper limit voltage of a storage battery having a highest voltage among the plurality of storage batteries of the battery pack, the predetermined lower limit voltage is a lower limit voltage of a storage battery having a lowest voltage among the plurality of storage batteries of the battery pack; The forward current is limited in amplitude so that the highest voltage battery does not exceed its upper voltage limit; The negative current is limited in amplitude so that the lowest voltage battery does not exceed a lower limit voltage of the battery; The bidirectional current is limited in amplitude so that the highest voltage storage battery does not exceed its upper limit voltage and the lowest voltage storage battery does not exceed its lower limit voltage, and the heat generation amount of the storage batteries is calculated. The temperature rise control device for a storage battery according to claim 2 .

6. The battery temperature rise control device according to any one of claims 1 to 5, wherein the frequencies of the positive current, the negative current, and the bidirectional current are higher than the frequencies at which the storage battery is charged or discharged by each of the currents.

7. 6. A temperature rise control device for a storage battery according to claim 1, wherein a current rest period between pulses of the intermittent pulse current of the positive current and the negative current is equal to or greater than a time constant of a charge / discharge reaction of the storage battery.

8. 6. The battery temperature rise control device according to claim 1, wherein the bidirectional current has a current integral value in one pulse of the positive current in the bidirectional current and a current integral value in one pulse of the negative current in the bidirectional current that is equal to each other.

9. A battery temperature rise control device as described in any one of claims 1 to 5, which stores a usage history of the storage battery, predicts the next start time of use based on the stored usage history, and passes a current through the storage battery so that the storage battery is heated to a predetermined temperature by the predicted start time of next use.

10. 6. A battery temperature rise control device as described in any one of claims 1 to 5, wherein after the storage battery has been heated to a predetermined temperature, a current in the bidirectional current mode having an amplitude equal to or less than a predetermined amplitude is caused to flow through the storage battery to maintain the temperature of the storage battery within a predetermined temperature range.

11. A storage battery heating system that heats up a storage battery by passing a current through the storage battery, the storage battery includes one or more devices that are connected to the storage battery and can cause a current in at least one of the following current modes to flow to the storage battery: a positive current mode in which a positive current that is an intermittent pulse current flows in a direction flowing into the storage battery, a negative current mode in which a negative current that is an intermittent pulse current flows in a direction flowing out of the storage battery, and a bidirectional current mode in which a bidirectional current in which one pulse of the positive current and one pulse of the negative current flow alternately flows; and the one or more devices can cause a current in the positive current mode, the negative current mode, and the bidirectional current mode to flow to the storage battery; Further, the battery heating system includes a battery heating control device that controls the one or more devices to select a current mode that generates the greatest amount of heat from the storage battery among the positive current mode, the negative current mode, and the bidirectional current mode, in response to the temperature of the storage battery and the voltage of the storage battery, and to flow current to the storage battery.

12. The temperature rise control device for the storage battery includes a voltage measurement unit that measures a voltage of the storage battery, and a heat generation amount calculation unit that calculates a heat generation amount of the storage battery due to a current flowing through the storage battery, The heat generation amount calculation unit, with respect to the voltage of the storage battery from the voltage measurement unit, a heat generation amount of the storage battery in the forward current mode in which the storage battery is heated by the forward current in which the amplitude of the current is limited by a predetermined upper limit voltage of the storage battery; a heat generation amount of the storage battery in the negative current mode in which the storage battery is heated by the negative current whose amplitude is limited by a predetermined lower limit voltage of the storage battery; and a heat generation amount of the storage battery in the bidirectional current mode in which the storage battery is heated by the bidirectional current in which the amplitude of the current is limited by the upper limit voltage and the lower limit voltage; The system for heating a storage battery according to claim 11 , wherein the system calculates the current mode in which the amount of heat generated is the largest, and controls the one or more devices so that a current flows through the storage battery in the current mode in which the amount of heat generated is the largest.

13. The temperature rise control device for the storage battery includes a voltage measurement unit that measures a voltage of the storage battery, and a heat generation amount calculation unit that calculates a heat generation amount of the storage battery due to a current flowing through the storage battery, the heat generation amount calculation unit compares the voltage of the storage battery from the voltage measurement unit with a median between a predetermined upper limit voltage of the storage battery and a predetermined lower limit voltage of the storage battery; when the voltage of the storage battery is lower than the median, a calculation is performed to determine an amount of heat generated by the storage battery in the forward current mode in which the storage battery is heated by the forward current, the amplitude of which is limited by the upper limit voltage, and an amount of heat generated by the storage battery in the bidirectional current mode in which the amplitude of the current is limited by the upper limit voltage and the lower limit voltage, and the one or more devices are controlled to flow a current to the storage battery in the current mode in which the amount of heat generated is greater; 12. The battery heating system of claim 11, wherein when the voltage of the storage battery is equal to or higher than the median, the amount of heat generated by the storage battery in the negative current mode, in which the storage battery is heated by the negative current whose amplitude is limited by the lower limit voltage, and the amount of heat generated by the storage battery in the bidirectional current mode, in which the storage battery is heated by the bidirectional current whose amplitude is limited by the upper limit voltage and the lower limit voltage, are calculated, and the one or more devices are controlled to pass current to the storage battery in the current mode which generates the greater amount of heat.

14. A storage battery heating system that heats up a storage battery by passing a current through the storage battery, the storage battery includes one or more devices that are connected to the storage battery and can cause a current to flow to the storage battery in at least one of a negative current mode in which a negative current flows as an intermittent pulse current flowing out of the storage battery, and a bidirectional current mode in which a bidirectional current flows in which one pulse of a positive current and one pulse of the negative current flow alternately as an intermittent pulse current flowing into the storage battery, the one or more devices being capable of causing the negative current mode and the bidirectional current mode to flow, and a temperature rise control device for a storage battery that controls the one or more devices to select, in response to a temperature of the storage battery and a voltage of the storage battery, one of the negative current mode and the bidirectional current mode, whichever produces a larger amount of heat generated by the storage battery, and to allow a current to flow through the storage battery; The temperature rise control device for the storage battery includes a voltage measurement unit that measures a voltage of the storage battery, and a heat generation amount calculation unit that calculates a heat generation amount of the storage battery due to a current flowing through the storage battery, When a difference between a voltage of the storage battery from the voltage measurement unit and a predetermined upper limit voltage of the storage battery is equal to or smaller than a predetermined value, the heat generation amount calculation unit A battery heating system that calculates the amount of heat generated by the storage battery in the negative current mode, in which the storage battery is heated by the negative current, the current amplitude of which is limited by a predetermined lower limit voltage of the storage battery, and the amount of heat generated by the storage battery in the bidirectional current mode, in which the storage battery is heated by the bidirectional current, the current amplitude of which is limited by the upper limit voltage and the lower limit voltage, and controls the one or more devices to flow current to the storage battery in the current mode that generates the greater amount of heat.

15. The storage battery heating system according to claim 11 , wherein the storage battery is a battery pack in which a plurality of storage batteries are connected in series and parallel.

16. The storage battery is a battery pack in which a plurality of storage batteries are connected in series and parallel, the heat generation amount calculation unit sets the predetermined upper limit voltage to an upper limit voltage of a storage battery having a highest voltage among the plurality of storage batteries of the battery pack, the predetermined lower limit voltage is a lower limit voltage of a storage battery having a lowest voltage among the plurality of storage batteries of the battery pack; The forward current is limited in amplitude so that the highest voltage battery does not exceed its upper voltage limit; The negative current is limited in amplitude so that the lowest voltage battery does not exceed a lower limit voltage of the battery; The bidirectional current is limited in amplitude so that the highest voltage battery does not exceed its upper voltage limit and the lowest voltage battery does not exceed its lower voltage limit. The heat generation amount of the storage battery is calculated by: The battery heating system according to claim 12.

17. The storage battery is a battery pack in which a plurality of storage batteries are connected in series and parallel, the heat generation amount calculation unit sets the predetermined upper limit voltage to an upper limit voltage of a storage battery having a highest voltage among the plurality of storage batteries of the battery pack, the predetermined lower limit voltage is a lower limit voltage of a storage battery having a lowest voltage among the plurality of storage batteries of the battery pack; The negative current is limited in amplitude so that the lowest voltage battery does not exceed a lower limit voltage of the battery; The amplitude of the bidirectional current is limited so that the highest voltage battery does not exceed the upper limit voltage of the battery, and the lowest voltage battery does not exceed the lower limit line voltage of the battery. The amount of heat generated is calculated as follows: The battery heating system according to claim 14.

18. A battery heating system as described in any one of claims 11 to 17, wherein the frequencies of the positive current, the negative current, and the bidirectional current are higher than the frequencies at which the storage battery is charged and discharged by each of the currents.

19. 18. A battery heating system as claimed in any one of claims 11 to 17, wherein a current rest period between pulses of the intermittent pulse current of the positive current and the negative current is equal to or greater than a time constant of the charge / discharge reaction of the battery.

20. The battery heating system according to any one of claims 11 to 17, wherein the bidirectional current has a current integral value in one pulse of the positive current in the bidirectional current that is equal to a current integral value in one pulse of the negative current in the bidirectional current.

21. A battery heating system as described in any one of claims 11 to 17, which stores a usage history of the storage battery, predicts the next start time of use based on the stored usage history, and passes a current through the storage battery so that the storage battery is heated to a predetermined temperature by the predicted start time of next use.

22. After the storage battery is heated to a predetermined temperature, a current in the bidirectional current mode having an amplitude equal to or less than a predetermined amplitude is caused to flow through the storage battery. The battery heating system according to claim 11 , wherein the temperature of the battery is kept within a predetermined temperature range.

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