Charging system

Abstract

To provide a charging system that always outputs a charging current of an appropriate value to a charging battery portion under an expected temperature environment.SOLUTION: A charging system 100 includes a charging control circuit 5. In the charging control circuit 5, an allowable AC current value AI1 in a charging battery unit 6 is determined on the basis of battery temperatures TS61 and TS62, and a generator side command current value AI2 is obtained on the basis of a selected rated current value I46. The selected rated current value I46 is one of a short-time rated current value I44 and a continuous rated current value I45. In the charging control circuit 5, the smaller of the allowable AC current value AI1 and the generator side command current value AI2 is selected as a determined charging current value DCI. The charging control circuit 5 outputs a charging current command value C5 for controlling the power generation operation of the power generation unit 80 such that the charging current output to the charging battery unit 6 becomes the determined charging current value DCI.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a charging system capable of charging a rechargeable battery unit. [Background technology]

[0002] Rechargeable batteries are used in many electrical appliances and devices. There is a demand for high-speed charging of rechargeable batteries, and a prior art document that enables high-speed charging of rechargeable batteries is, for example, the high-speed charging system disclosed in Patent Document 1. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-123332 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional high-speed charging system disclosed in Patent Document 1 employs a control method for charging the rechargeable battery unit with a temporarily large charging current in order to charge the rechargeable battery unit at high speed.

[0005] Generally, the internal resistance of the battery cells that make up the rechargeable battery unit tends to increase at low temperatures, reducing charging efficiency. In addition, the charging value unit has the characteristic that the allowable charging current value changes based on the battery temperature.

[0006] Conventional high-speed charging systems do not take into account the battery temperature of the rechargeable battery unit, which means that there is a risk that a charging current exceeding the allowable charging current value may be output to the charging unit.

[0007] The present disclosure has been made to solve the above problems, and aims to provide a charging system that always outputs a charging current of an appropriate value to a charging unit for a rechargeable battery unit under an expected temperature environment. [Means for solving the problem]

[0008] a power generation unit that performs a power generation operation and outputs a charging current to the rechargeable battery unit based on the generated power obtained by the power generation operation; and a charge control circuit that receives the detected battery temperature and controls the power generation operation of the power generation unit, wherein the charge control circuit includes an allowable charging current value calculation circuit that calculates an allowable charging current value in the rechargeable battery unit based on the detected battery temperature, and a power generation-side current command value output circuit that outputs a power generation-side command current value based on a selected rated current value in the power generation operation, wherein the selected rated current value is one of a continuous rated current value and a short-time rated current value that exceeds the continuous rated current value, and the charge control circuit further includes a charge current value determination circuit that determines the smaller of the allowable charging current value and the power generation-side command current value as a determined charging current value, and the charge control circuit controls the power generation operation of the power generation unit so that the charging current output to the rechargeable battery unit is the determined charging current value. [Effects of the Invention]

[0009] The charging control circuit in the charging system of the present disclosure controls the power generation operation of the power generation unit so that the charging current output to the rechargeable battery unit is a determined charging current value that does not exceed the allowable charging current value calculated based on the detected battery temperature.

[0010] Therefore, by taking into account changes in the detected battery temperature of the rechargeable battery unit, the charging system of the present disclosure can always output a charging current of an appropriate determined charging current value to the rechargeable battery unit under expected temperature environments. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram showing a configuration of a charging system according to an embodiment of the present disclosure; [Figure 2]2 is an explanatory diagram for explaining a continuous rating and a short-time rating in the power generation unit shown in FIG. 1. FIG. [Figure 3] 2 is a graph showing the change in allowable charging current with battery temperature in the rechargeable battery unit shown in FIG. 1. [Figure 4] 2 is a graph showing the change in internal resistance of a battery cell in the rechargeable battery unit shown in FIG. 1 with battery temperature. [Figure 5] FIG. 2 is a block diagram (part 1) showing the internal configuration of the charge control circuit shown in FIG. [Figure 6] FIG. 2 is a block diagram (part 2) showing the internal configuration of the charge control circuit shown in FIG. [Figure 7] 4 is a graph showing changes in battery temperature over time during a charging operation of the charging system according to the embodiment. [Figure 8] 10 is a graph showing the open / closed states of three switches during the charging operation. [Figure 9] 10 is a graph showing the change over time in the final charging current value during the charging operation. [Figure 10] 6 is a graph showing changes over time in the charging current and the generator output current during the charging operation. DETAILED DESCRIPTION OF THE INVENTION

[0012] (Overall composition) FIG. 1 is a block diagram showing the configuration of a charging system 100 according to an embodiment of the present disclosure.

[0013] As shown in the figure, the charging system 100 includes, as its main components, a power generation unit 80, a charging control circuit 5, a rechargeable battery unit 6, a heater 7, a cooling device 8, temperature sensors 61 and 62, switches SW1 to SW3, current sensors IS2 to IS4, voltage sensors VS1 and VS2, wiring L2a and L2b, wiring L3 and L4, and resistors R1 and R2.

[0014] The power generation unit 80 includes, as main components, an engine (EG) 1, a generator 2, a rectifier 3, an excitation control device 4, a refrigerant temperature sensor 15, a wire L1, and a current sensor IS1.

[0015] The rechargeable battery unit 6 has multiple rechargeable battery cells inside. Temperature sensors 61 and 62 are provided for the rechargeable battery unit 6. The temperature sensors 61 and 62 are battery temperature sensors that detect battery temperatures TS61 and TS62, respectively. It is desirable that one of the temperature sensors 61 and 62 be used to measure a battery cell that is most likely to reach a high temperature, and the other be used to measure a battery cell that is most likely to reach a low temperature. The number of temperature sensors is not limited to two, and more than three may be provided.

[0016] A refrigerant temperature sensor 15 is provided in the generator 2. A detected refrigerant temperature TS1, which is the temperature of the refrigerant that cools the generator 2, is detected by the refrigerant temperature sensor 15, which is a power generation side temperature sensor.

[0017] The refrigerant temperature sensor 15 is a power generation side temperature sensor disposed in the generator 2. If the generator 2 has refrigerant piping, the refrigerant temperature sensor 15 may be provided in the refrigerant piping portion outside the generator 2.

[0018] As described above, the power generation unit 80 includes the prime mover 1 (EG1), the generator 2, the rectifier 3, and the excitation control device 4. The prime mover 1 is configured to transmit mechanical energy to the rotor of the generator 2 via a rotating shaft, gears, etc. The prime mover 1 is, for example, an internal combustion engine. The prime mover 1 may also be a steam turbine, a gas turbine, a water turbine, a wind turbine, or the like.

[0019] The power generation unit 80 generates power using the generator 2, and outputs to the rechargeable battery unit 6 a charging current I6 based on the generated power obtained by this power generation operation.

[0020] The generator 2 performs a power generation operation to generate AC power by converting mechanical energy into electrical energy. The generated voltage of the generator 2 is changed by adjusting the excitation current in the excitation control device 4.

[0021] The excitation control device 4 outputs an excitation current based on a charging current command value C5 from the charging control circuit 5, thereby controlling the output voltage obtained by the power generation operation of the generator 2. The generator 2 and the rectifier 3 are connected via a wiring L1, and the generated current of the AC power obtained by the power generation operation of the generator 2 is transmitted to the rectifier 3 via the wiring L1.

[0022] The rectifier 3 converts the AC power output from the generator 2 into DC power. The rectifier 3 is connected to the rechargeable battery unit 6 via wires L2a and L2b, which serve as power wires. Therefore, the rectifier 3 outputs the current included in the converted DC power as a charging current to the rechargeable battery unit 6. In this case, the wire L2b to which the anode of the rectifier 3 is connected is the negative side, and the wire L2a to which the cathode of the rectifier 3 is connected is the positive side.

[0023] The charging system 100 of this embodiment has a heater 7 and a cooling device 8 as auxiliary circuits. The heater 7 and the cooling device 8 are arranged near the rechargeable battery unit 6. The heater 7 performs a heating operation on the rechargeable battery unit 6, and the cooling device 8 performs a cooling operation on the rechargeable battery unit 6. The heating operation by the heater 7 and the cooling operation by the cooling device 8 are performed under the control of the charging control circuit 5.

[0024] Temperature sensors 61 and 62, each a battery temperature sensor, are provided at a predetermined distance from heater 7 and cooling device 8 so as not to be affected by the heating operation of heater 7 and the cooling operation of cooling device 8 compared to rechargeable battery section 6.

[0025] Resistors R1 and R2 are connected in series between wires L2a and L2b, and a node N1 between the resistors R1 and R2 is set to the ground potential, which is the reference potential. A switch SW1 is provided on wire L2a, and when switch SW1 is in the "closed state" (ON state), a charging current flows through wire L2a, but when switch SW1 is in the "open state" (OFF state), no charging current flows through wire L2a.

[0026] A voltage sensor VS1 is provided between the wires L2a and L2b on the rectifier 3 side, with the switch SW1 as the reference. The DC output voltage V2 is detected by the voltage sensor VS1. A voltage sensor VS2 is provided between the wires L2a and L2b on the rechargeable battery unit 6 side, with the switch SW1 as the reference. The charging voltage V6 of the rechargeable battery unit 6 is detected by the voltage sensor VS2. Furthermore, a current sensor IS2 is provided on the wire L2a on the rechargeable battery unit 6 side, with the switch SW1 as the reference. The charging current I6 is detected by the current sensor IS2.

[0027] A current sensor IS1, which is a power generation side current sensor, is provided on the wiring L1, and the current sensor IS1 detects a power generator output current I2, which is a power generation current.

[0028] The wiring L1 is connected to the wiring L3 via the switch SW2. Therefore, when the switch SW2 is in the "closed state," the wiring L1 and the wiring L3 are electrically connected, and when the switch SW2 is in the "open state," the wiring L1 and the wiring L3 are electrically disconnected.

[0029] The current flowing through the wiring L3 is the current for the cooling device 8 to perform the cooling operation. A current sensor IS3 is provided on the wiring L3, and the current sensor IS3 detects the cooling device current I8. The current sensor IS3 serves as a cooling device current sensor.

[0030] That is, a supply current based on the power generated by the power generation unit 80 is supplied to the cooling device 8, so that the cooling device 8 can perform a cooling operation.

[0031] The wiring L1 is connected to the wiring L4 via the switch SW3. Therefore, when the switch SW3 is in the "closed state," the wiring L1 and the wiring L4 are electrically connected, and when the switch SW3 is in the "open state," the wiring L1 and the wiring L4 are electrically disconnected.

[0032] The current flowing through the wire L4 is used for the heater 7 to perform a heating operation. A current sensor IS4 is provided on the wire L4, and the current sensor IS4 detects the heater current I7. The current sensor IS4 serves as a heater current sensor.

[0033] That is, a supply current based on the power generated by the power generation unit 80 is supplied to the heater 7, so that the heater 7 can perform a heating operation.

[0034] The power generation operation of the power generation unit 80 can be performed within the continuous rated range or for short periods exceeding the continuous rated range. That is, the power generation unit 80 operates within the continuous rated range in the normal charging mode, and operates above the continuous rated range in the fast charging mode. Specifically, in the fast charging mode, the power generation unit 80 operates above the continuous rated range but within the short-term rated range.

[0035] Here, the continuous rating is a rating that is based on the assumption that power generation unit 80 will be used continuously. In contrast, the short-term rating is a rating that is based on the assumption that power generation unit 80 will be used for only a short period of time (e.g., 30 minutes or 1 hour).

[0036] When power generating unit 80 is used within the continuous rating range, power generating unit 80 can be used continuously for a relatively long period of time. On the other hand, when power generating unit 80 is used within the short-term rating range, power generating unit 80 can be used without any abnormalities for the expected short period of time.

[0037] FIG. 2 is an explanatory diagram for explaining the performance of the power generating unit 80, that is, the continuous rating and short-time rating of the power generating unit 80. As shown in FIG.

[0038] 2, the rechargeable battery unit 6 is used in the voltage range of V100 or less and V200 or more. Therefore, the power generation unit 80 is used for the rechargeable battery unit 6 when the power generation / output voltage is in the voltage range of V100 or less and V200 or more.

[0039] The solid line in Fig. 2 indicates the continuous rated characteristics, and within the range to the left of the solid line, power generation unit 80 can be used continuously for a long period of time without any abnormalities. Also, the dashed dotted line in Fig. 2 indicates the short-term rated characteristics, and within the range from the solid line to the dashed dotted line, power generation unit 80 can be used for a specified short period of time without any abnormalities.

[0040] As shown in Figure 2, the solid line indicating the continuous rating characteristic changes so that the product of voltage and current becomes a constant power W1, while the dashed-dotted line indicating the short-term rating characteristic changes so that the product of voltage and current becomes a constant power W2.

[0041] The charge control circuit 5 receives a charge command C1 from a higher-level device (not shown), a detected refrigerant temperature TS1 from refrigerant temperature sensor 15, which is a power generation-side temperature sensor, and detected battery temperatures TS61 and TS62 from temperature sensors 61 and 62, which are battery temperature sensors. The charge control circuit 5 also receives a DC output voltage V2 from voltage sensor VS1 and a charging voltage V6 from voltage sensor VS2.

[0042] The charging control circuit 5 further receives the generator output current I2, which is the power generation current, from current sensor IS1, which is the power generation side current sensor, receives the charging current I6 from current sensor IS2, receives the cooling device current I8 from current sensor IS3, which is the cooling device current sensor, and receives the heater current I7 from current sensor IS4, which is the heater current sensor.

[0043] The charging control circuit 5 then outputs a charging current command value C5 to the excitation control device 4, and outputs switch operation signals S1 to S3 to the switches SW1 to SW3. It also outputs a charging completion signal S5 to a higher-level device. The higher-level device may be, for example, an operation and monitoring panel of the charging system 100.

[0044] The charge control circuit 5 is configured with a PLC (Programmable Logic Controller) or the like, and controls the charge current output from the power generation unit 80 by providing a charge current command value C5 to the excitation control device 4 of the power generation unit 80. That is, the charge control circuit 5 provides the charge current command value C5 to control the excitation current by the excitation control device 4, thereby changing the generated current output from the power generation unit 80. As a result, the charge current I6 for the rechargeable battery unit 6 also changes.

[0045] The charging control circuit 5 can also monitor the charging voltage V6 from the voltage sensor VS2, and the charging control circuit 5 can also monitor the DC output voltage V2 from the voltage sensor VS1.

[0046] Additionally, the charge control circuit 5 can monitor the charge current I6 from the current sensor IS2, the refrigerant temperature TS1 detected from the refrigerant temperature sensor 15, and the battery temperatures TS61 and TS62 detected from the temperature sensors 61 and 62.

[0047] The configuration and operation of the charging control circuit 5 will be described later.

[0048] The rechargeable battery unit 6 is composed of a plurality of battery cells, each of which is rechargeable. The rechargeable battery unit 6 is charged by receiving a charging current based on the generated power output from the power generation unit 80. Although not shown in FIG. 1, a load is connected to the rechargeable battery unit 6. The rechargeable battery unit 6 electrically drives the load by outputting (discharging) charging power to the load.

[0049] In the charging system 100 of the present embodiment configured as described above, the power generating unit 80 including the generator 2 performs a power generating operation. A charging current I6 based on the generated power (including the DC output voltage V2) obtained by this power generating operation is output to the rechargeable battery unit 6.

[0050] (Allowable charging current IcL of the rechargeable battery unit 6) FIG. 3 is a graph schematically showing the change in the allowable charging current IcL with respect to the battery temperature in the rechargeable battery unit 6. As shown in the figure, the allowable charging current IcL changes depending on the battery temperature T. That is, the allowable charging current IcL is represented by a function IcL(T) having the battery temperature T as an argument. The function IcL(T) of the rechargeable battery unit 6 can be obtained experimentally or theoretically.

[0051] As shown in FIG. 3, the allowable charging current IcL in the rechargeable battery unit 6 becomes the allowable charging current value IcLT5 at the maximum value when the battery temperature is T5. Hereinafter, in this description, the temperature of the rechargeable battery unit 6 at which the allowable charging current IcL is maximum is referred to as the charging peak temperature. The function IcL(T) has a temperature characteristic in which the allowable charging current IcL increases in the first temperature range (T1 to T5) below the battery temperature T5, which is the charging peak temperature, and the allowable charging current IcL decreases in the second temperature range (T5 to T8) above the battery temperature T5. In the range below the battery temperature T1 and the range above the battery temperature T8, the function IcL(T) becomes "0".

[0052] Here, the battery temperature T1 is lower than the battery temperature T2, the battery temperature T2 is lower than the battery temperature T3, the battery temperature T3 is lower than the battery temperature T4, the battery temperature T4 is lower than the battery temperature T5, the battery temperature T5 is lower than the battery temperature T6, and the battery temperature T6 is lower than the battery temperature T7.

[0053] In the above-described first temperature range (T1 to T5), the allowable charging current IcL of the rechargeable battery unit 6 at the battery temperature T2 becomes the allowable charging current value IcLT2. Similarly, the allowable charging current IcL of the rechargeable battery unit 6 at the battery temperatures T3 and T4 becomes the allowable charging current values IcLT3 and IcLT4, respectively. The allowable charging current values IcLT2 to IcLT5 have a magnitude relationship of {IcLT2 < IcLT3 < IcLT4 < IcLT5}.

[0054] In the second temperature range (T5 to T8) described above, the allowable charging current IcL of the rechargeable battery unit 6 at battery temperature T6 is the allowable charging current value IcLT6. Similarly, the allowable charging current IcL of the rechargeable battery unit 6 at battery temperature T7 is the allowable charging current value IcLT7. The allowable charging current values ​​IcLT5 to IcLT7 have the magnitude relationship {IcLT5>IcLT6>IcLT7}.

[0055] In this embodiment, the DC continuous rated current value DI45 is set to a current value that is greater than the allowable charging current value IcLT2 and smaller than the allowable charging current values ​​IcLT3 and IcLT7. The DC continuous rated current value DI45 is the current value obtained by converting the continuous rated current value I45 of the generator 2 into a DC value.

[0056] If the rechargeable battery unit 6 is charged at a temperature below T1, the rechargeable battery unit 6 rapidly deteriorates and its SOC (State Of Charge) drops. For this reason, temperatures below T1 are considered to be in the charging prohibited temperature range. For the same reason, temperatures above T8 are also considered to be in the charging prohibited temperature range.

[0057] Furthermore, charging of the rechargeable battery unit 6 is not performed in the range of battery temperatures T1 to T2 either. The following first and second reasons are considered as the reasons for this.

[0058] The first reason is to provide a margin for battery temperature T1, and to prevent the rechargeable battery unit 6 from being erroneously charged at battery temperature T1 due to variations in temperature measurement, measurement errors, or the like.

[0059] The second reason is that it becomes difficult to control the power generation unit 80 including the generator 2 to set a current value that is extremely smaller than the continuous rated current value of the generator 2 (for example, 0.1% of the DC continuous rated current value DI45), and it is necessary to charge at a controllable current value, taking into account the accuracy of current control for the power generation unit 80.

[0060] For the same reason as in the battery temperature range T1 to T2, charging of the rechargeable battery unit 6 is not performed in the battery temperature range T7 to T8. Therefore, the battery temperature range T2 to T7 is set as the range in which the rechargeable battery unit 6 can be charged.

[0061] The section between battery temperatures T2 and T3 is the heating operation section of the heater 7 in the normal charging mode, and the section between battery temperatures T2 and T4 is the heating operation section of the heater 7 in the high-speed charging mode.

[0062] Because the heater 7 receives power from the power generation unit 80, which includes the generator 2, the charging current to the rechargeable battery unit 6 is reduced by the amount corresponding to the heating operation of the heater 7. For this reason, it is preferable not to use the heater 7. However, if the heater 7 is not being used to heat, the charging current must be intentionally reduced to stay below the allowable charging current IcL, even though there is a margin in the DC continuous rated current value DI45 from the perspective of the temperature characteristics of the function IcL(T). In this way, the heating operation period of the heater 7 is set taking into consideration the trade-off between the allowable output current of the generator 2, the current consumption of the heater 7, and the temperature characteristics of the function IcL(T).

[0063] The upper limit temperature for the heating operation section in fast charging mode is set to battery temperature T4 (>T3) because the DC short-time rated current DI44 is greater than the DC continuous rated current DI45, leaving room for more current, and so priority is given to reaching the maximum allowable charging current IcLT5 as quickly as possible in order to shorten the time until charging is completed. The DC short-time rated current DI44 of generator 2 is converted to DC and becomes the DC short-time rated current DI44.

[0064] Furthermore, the section between battery temperatures T6 and T7 is set as the cooling operation section for cooling device 8. The following first to fourth reasons are considered as reasons for setting the cooling operation section.

[0065] The first reason is that by charging the rechargeable battery unit 6 in a temperature environment where the allowable charging current IcL becomes a large current value near the allowable charging current value IcLT5, the charging current is increased and the rechargeable battery unit 6 is charged early.

[0066] The second reason is that charging the rechargeable battery unit 6 in a high temperature range exceeding battery temperature T6 shortens the life of the battery cells in the rechargeable battery unit 6, so charging the rechargeable battery unit 6 in a high temperature range should be avoided as much as possible.

[0067] The third reason is that if the difference between battery temperature T5 and battery temperature T6 is small, the cooling operation of cooling device 8 will be performed more than necessary due to a temperature imbalance between the multiple battery cells in rechargeable battery unit 6, and as a result, the battery temperature of rechargeable battery unit 6 will drop significantly below battery temperature T5, and it may not be possible to charge rechargeable battery unit 6 at around the allowable charging current value IcLT5.

[0068] The fourth reason is to prevent a vicious cycle in which resistance differences occur due to temperature differences between multiple battery cells connected in parallel, which promotes current imbalance between the multiple battery cells and increases the temperature difference and resistance difference between the multiple battery cells.

[0069] Since power loss is proportional to the square of the current, the imbalance in current among the plurality of battery cells described above is undesirable. Generally, the rechargeable battery unit 6 is made up of a plurality of battery cells connected in parallel.

[0070] (battery cell internal resistance Rb) Fig. 4 is a graph that schematically shows how the internal resistance Rb of a battery cell changes with battery temperature. That is, Fig. 4 shows how the internal resistance Rb of each of the multiple battery cells in the rechargeable battery unit 6 changes with battery temperature. As shown in the figure, the internal resistance Rb of a battery cell changes with battery temperature T. Therefore, the internal resistance Rb is expressed as a function Rb(T) with battery temperature T as an argument.

[0071] 4, the internal resistance Rb of a battery cell has a temperature characteristic in which it decreases as the battery temperature T increases. The internal resistance Rb of a battery cell exhibits an internal resistance value RbT1 at battery temperature T1, an internal resistance value RbT2 at battery temperature T2, an internal resistance value RbT3 at battery temperature T3, and an internal resistance value RbT4 at battery temperature T4. Furthermore, the internal resistance Rb of a battery cell exhibits an internal resistance value RbT5 at battery temperature T5, an internal resistance value RbT6 at battery temperature T6, and an internal resistance value RbT7 at battery temperature T7.

[0072] The internal resistance values ​​RbT1 to RbT7 have a magnitude relationship of {RbT1>RbT2>RbT3>RbT4>RbT5>RbT6>RbT7}.

[0073] As described above, the internal resistance Rb of the battery cell has a temperature characteristic in which the resistance value decreases as the temperature rises, and since the rechargeable battery unit 6 is generally composed of multiple battery cells connected in parallel, it can be seen that a temperature difference between the multiple battery cells will result in a resistance difference.

[0074] That is, when the battery temperature of a localized portion of the multiple battery cells (hereinafter abbreviated as "battery cell X") rises, the internal resistance Rb of battery cell X decreases, and as a result, the amount of current flowing through battery cell X increases. As the current increases, the battery temperature of battery cell X further increases. Thereafter, the decrease in internal resistance Rb, the increase in the amount of current, and the increase in temperature for battery cell X circulate, and this increases the current imbalance among the multiple battery cells, including battery cell X.

[0075] In the charging system 100 of the present disclosure, charging of the rechargeable battery unit 6 is not performed at battery temperature T7 or higher, so the current imbalance described above can be minimized.

[0076] (Charging control circuit 5) Figures 5 and 6 are block diagrams showing the internal configuration of the charge control circuit 5. Figures 5 and 6 are divided by a cutting line LC, with Figure 5 showing the circuit configuration above the cutting line LC and Figure 6 showing the circuit configuration below the cutting line LC. The configuration and operation of the charge control circuit 5 will be described below with reference to Figures 5 and 6.

[0077] The average value calculation circuit 11, maximum value selection circuit 12 and minimum value selection circuit 13 receive the detected battery temperatures TS61 and TS62, respectively.

[0078] The average value calculation circuit 11 calculates the average value of the detected battery temperatures TS61 and TS62 and outputs an average value signal S11 indicating the average value. The maximum value selection circuit 12 selects the maximum value between the detected battery temperatures TS61 and TS62 and outputs a maximum value signal S12 indicating the maximum battery temperature value Tmax. The minimum value selection circuit 13 selects the minimum value between the detected battery temperatures TS61 and TS62 and outputs a minimum value signal S13 indicating the minimum battery temperature value Tmin.

[0079] The charge amount determination circuit 10 receives the charging voltage V6 and charging current I6 from the outside, and receives an average value signal S11 from an internal average value calculation circuit 11. When the charging voltage V6 reaches the charge determination voltage, indicating full charge, the charge amount determination circuit 10 determines that charging is complete and outputs a charge completion signal S5 of "H". If the charge amount determination circuit 10 does not determine that charging is complete, it outputs a charge completion signal S5 of "L". The charge completion signal S5 is output to an external higher-level device.

[0080] The charge amount determination circuit 10 can increase or decrease the charge determination voltage based on the average battery temperature indicated by the average value signal S11. The charge amount determination circuit 10 can also determine whether charging is complete based on the integral value (amount of charge) of the charging current I6 instead of the charging voltage V6.

[0081] The comparator group 20 is composed of comparators 22 to 26. The comparator 22 receives the maximum value signal S12, compares the maximum battery temperature Tmax indicated by the maximum value signal S12 with the battery temperature T7, and outputs a comparison result signal S22 of “H” when {Tmax>T7}, and “L” when {Tmax≦T7}. The reason why the comparator 22 receives the maximum value signal S12 is that when at least one battery cell in the rechargeable battery unit 6 exceeds the battery temperature T7, there is a high possibility that some abnormality has occurred. Therefore, it is to prevent an extended failure of the charging system 100.

[0082] The comparator 23 receives the minimum value signal S13, compares the minimum battery temperature Tmin indicated by the minimum value signal S13 with the battery temperature T2, and outputs a comparison result signal S23 of “H” when {Tmin<T2}, and “L” when {Tmin≧T2}.

[0083] The comparator 24 receives the maximum value signal S12, compares the maximum battery temperature Tmax indicated by the maximum value signal S12 with the battery temperature T6, and outputs a comparison result signal S24 of “H” when {Tmax>T6}, and “L” when {Tmax≦T6}. The reason why the comparator 24 receives the maximum value signal S12 is due to considering that when at least one battery cell in the rechargeable battery unit 6 reaches the battery temperature T6, the allowable charging current IcL drops below the allowable charging current value IcLT5. Therefore, when the comparison result signal S24 becomes “H”, the cooling device 8 can be immediately made to execute a cooling operation to lower the battery temperature T of the rechargeable battery unit 6 and make the allowable charging current IcL approach the allowable charging current value IcLT5.

[0084] The comparator 25 receives the minimum value signal S13, compares the minimum battery temperature Tmin indicated by the minimum value signal S13 with the battery temperature T3, and outputs a comparison result signal S25 of “H” when {Tmin<T3}, and “L” when {Tmin≧T3}.

[0085] Comparator 26 receives the minimum value signal S13, compares the minimum battery temperature Tmin indicated by the minimum value signal S13 with the battery temperature T4, and outputs a comparison result signal S26 of “H” when {Tmin < T4} and “L” when {Tmin ≥ T4}.

[0086] NOT gate G1 receives the charge completion signal S5 and outputs a logic signal SG1 indicating the NOT operation result of the charge completion signal S5 as “H” or “L”. Note that the NOT operation is an operation that logically inverts a logical value (“H”, “L”).

[0087] OR gate G2 receives the comparison result signals S22 and S23 and outputs a logic signal SG2 indicating the OR operation result of the comparison result signals S22 and S23 as “H” or “L”. Note that the OR operation is an operation that obtains the logical sum of multiple input signals.

[0088] NOT gate G3 receives the logic signal SG2 and outputs a logic signal SG3 indicating the NOT operation result of the logic signal SG2 as “H” or “L”.

[0089] AND gate G4 receives the logic signal SG1, the logic signal SG3, and the charge command C1. The charge command C1 indicates the validity / invalidity of the charge command as “H” / “L”. AND gate G4 outputs a switch operation signal S1 indicating the AND operation result of the logic signal SG1, the logic signal SG3, and the charge command C1 as “H” or “L” to an external switch SW1. Note that the AND operation is an operation that obtains the logical product of multiple input signals.

[0090] The switch operation signal S1 output from AND gate G4 indicates the “closed state” (ON state) for switch SW1 as “H” and the “open state” (OFF state) for switch SW1 as “L”.

[0091] The switch operation signal S1 becomes “H” when the logic signal SG1 indicates “H” for incomplete charging, the logic signal SG3 indicates that the battery temperature T is {T2 ≤ T ≤ T7}, and the charge command C1 indicates that the charge command is valid as “H”.

[0092] When the switch operation signal S1 of "H" is output to the switch SW1, the switch SW1 is in the "closed state." When the switch SW1 is in the "closed state," the power generation unit 80 and the rechargeable battery unit 6 are electrically connected, and the charging operation for the rechargeable battery unit 6 is performed.

[0093] On the other hand, when the switch SW1 is set to the "open state" upon receiving the switch operation signal S1 of "L", the electrical connection between the power generation unit 80 and the rechargeable battery unit 6 is cut off, and therefore the charging operation for the rechargeable battery unit 6 is not performed.

[0094] The AND gate G5 receives the logic signal SG1 and the charge command C1, and outputs a logic signal SG5 which indicates the AND operation result of the logic signal SG1 and the charge command C1 by "H" or "L".

[0095] The AND gate G6 receives the comparison result signal S24 and the charge command C1, and outputs a switch operation signal S2 indicating the AND operation result of the comparison result signal S24 and the charge command C1 as "H" or "L" to the external switch SW2.

[0096] The switch operation signal S2 becomes "H" when the comparison result signal S24 is "H" indicating that the battery temperature is higher than battery temperature T6, and the charge command C1 is "H" indicating that the charge command is valid.

[0097] When the switch operation signal S2 of "H" is output to the switch SW2, the switch SW2 is in the "closed state." When the switch SW2 is in the "closed state," the power generation unit 80 and the cooling device 8 are electrically connected, so the cooling device 8 can perform a cooling operation. On the other hand, when the switch SW2 is in the "open state," the power generation unit 80 and the cooling device 8 are electrically disconnected, so the cooling device 8 does not perform a cooling operation.

[0098] In this way, the charge control circuit 5 outputs the switch operation signal S2 from the AND gate G6, thereby performing a cooling control operation to cause the cooling device 8 to perform a cooling operation when the battery temperature T of the rechargeable battery unit 6 is equal to or higher than the battery temperature T6, which is the cooling reference temperature. The battery temperature T6, which is the cooling reference temperature, is higher than the battery temperature T5, which is the charging peak temperature.

[0099] Furthermore, charging system 100 has multiple battery temperature sensors, temperature sensors 61 and 62, and the detected battery temperatures TS61 and TS62 detected by temperature sensors 61 and 62 become multiple detected battery temperatures. Note that although there are two battery temperature sensors in Fig. 1, the number is not limited to two, and two or more battery temperature sensors may be provided.

[0100] The cooling control operation of the cooling device 8 by the charge control circuit 5 is an operation to cause the cooling device 8 to perform the cooling operation when the maximum battery temperature Tmax, which is the maximum value of the detected battery temperatures TS61 and TS62, is equal to or higher than the cooling reference temperature (battery temperature T6).

[0101] The AND gate G9 receives the comparison result signal S26 and the comparison result signal S21. The comparison result signal S21 indicates the high-speed charging mode when it is "H" and the normal charging mode when it is "L". The AND gate G9 outputs a logic signal SG9 that indicates the AND operation result of the comparison result signal S26 and the comparison result signal S21 as "H" or "L".

[0102] OR gate G7 receives comparison result signal S25 and logic signal SG9, and outputs logic signal SG7 which indicates the OR operation result of comparison result signal S25 and logic signal SG9 with "H" or "L".

[0103] The AND gate G8 receives the logic signal SG7 and the charge command C1, and outputs a switch operation signal S3 indicating the AND operation result of the logic signal SG7 and the charge command C1 as "H" or "L" to the external switch SW3.

[0104] The switch operation signal S3 becomes "H" when the logic signal SG7 is "H" indicating that the battery temperature is lower than battery temperature T3 or that the battery temperature is lower than battery temperature T4 in high-speed charging mode, and the charge command C1 is "H" indicating that the charge command is valid.

[0105] When the switch operation signal S3 of "H" is output to the switch SW3, the switch SW3 is in the "closed state." When the switch SW3 is in the "closed state," the power generation unit 80 and the heater 7 are electrically connected, so the heater 7 can perform a heating operation. On the other hand, when the switch SW3 is in the "open state," the power generation unit 80 and the heater 7 are electrically disconnected, so the heater 7 does not perform a heating operation.

[0106] In this way, the charge control circuit 5 outputs the switch operation signal S3 from the AND gate G8, thereby performing a heating control operation to make the heater 7 perform a heating operation when the battery temperature T of the rechargeable battery unit 6 is equal to or lower than the heating reference temperature, battery temperature T3 or battery temperature T4. The heating reference temperatures, battery temperature T3 and battery temperature T4, are lower than battery temperature T5, which is the peak charging temperature.

[0107] The heating control operation of the heater 7 by the charge control circuit 5 is an operation to make the heater 7 perform a heating operation when the minimum battery temperature value Tmin, which is the minimum value of the detected battery temperatures TS61 and TS62, is equal to or lower than the heating reference temperature (battery temperature T3 or battery temperature T4).

[0108] The heating reference temperatures include a first heating reference temperature, battery temperature T3, and a second heating reference temperature, battery temperature T4, which is higher than battery temperature T3.

[0109] The charge control circuit 5 sets the heating reference temperature to battery temperature T3, which is the first heating reference temperature, in the normal charge mode where the selected rated current value I46 is the continuous rated current value I45. The charge control circuit 5 also sets the heating reference temperature to battery temperature T4, which is the second heating reference temperature, in the fast charge mode where the selected rated current value I46 is the short-term rated current value I44.

[0110] The allowable charging current calculation circuit 31 (IcL(T) calculation 31) receives the maximum value signal S12, and outputs the allowable charging current value IX by applying the function IcL(T) shown in FIG. 3 using the maximum battery temperature Tmax indicated by the maximum value signal S12 as an argument.

[0111] The allowable charging current calculation circuit 32 (IcL(T) calculation 32) receives the minimum value signal S13, and outputs the allowable charging current value IZ by applying the function IcL(T) shown in Figure 3 using the battery temperature minimum value Tmin indicated by the minimum value signal S13 as an argument.

[0112] The minimum value selection circuit 33 receives the allowable charging current values ​​IX and IZ, and outputs the minimum allowable charging current value Imin, which is the minimum value of the allowable charging current values ​​IX and IZ.

[0113] The conversion circuit 34 receives the minimum allowable charging current value Imin, converts the minimum allowable charging current value Imin into a three-phase AC current value, and outputs the converted current value as the allowable AC current value AI1. The allowable AC current value AI1 becomes the finally determined allowable charging current value.

[0114] The above-mentioned maximum value selection circuit 12, minimum value selection circuit 13, allowable charging current calculation circuit 31, allowable charging current calculation circuit 32, minimum value selection circuit 33 and conversion circuit 34 constitute an allowable charging current value calculation circuit.

[0115] The allowable charging current value calculation circuit calculates the allowable AC current value AI1 in the rechargeable battery unit 6 converted into a three-phase AC value as the allowable charging current value based on the detected battery temperatures TS61 and TS62.

[0116] (Power generation side current command value output circuit 40 in the charging control circuit 5) The configuration and operation of the power generation side current command value output circuit 40 will be described below with reference to Fig. 6. The current values ​​handled in the power generation side current command value output circuit 40 are three-phase AC current values.

[0117] The short-time rated current setting circuit 44 outputs a preset short-time rated current value I 44 to an input terminal A of the selection switch 46 .

[0118] The short-time rated current value I44 is selected to be a value that exceeds the continuous rated current value of the power generation unit 80, for example, using the graph shown in Fig. 2. For example, assume that a value that exceeds the current value I200 is selected as the short-time rated current value I44 within the usable power generation range (V100 to V200) of the power generation unit 80. In this case, the short-time rated current value I44 will always be a value that exceeds the continuous rated current value of the power generation unit 80 within the usable power generation range (V100 to V200).

[0119] To select a value exceeding the current value I200, the user may refer to FIG. 2 and select the current value I100, which is the maximum short-time rated current in the usable power generation range (V100 to V200), as the short-time rated current value I44. Alternatively, a current value exceeding the current value I100 can be selected as the short-time rated current value I44. In this case, it goes without saying that the usable time will be shortened. From the viewpoint of high-speed charging, it is desirable to select a large short-time rated current value I44.

[0120] On the other hand, the continuous rated current calculation circuit 45 receives the detected refrigerant temperature TS1, performs calculation processing based on the detected refrigerant temperature TS1 to calculate the continuous rated current value I45, and outputs the continuous rated current value I45 to input terminal B of the continuous rated current calculation circuit 45.

[0121] The continuous rated current calculation circuit 45 obtains the continuous rated current value I45 as follows: If the cumulative allowable value when the generator 2 is at the reference temperature TR1 is the reference continuous rated current value I45(0), the continuous rated current value I45 is calculated by the following formula (1).

[0122] I45=I45(0)-K1×(TS1-TR1)…(1) Note that "K1" is a proportional multiplier (positive value).

[0123] As shown in equation (1), the higher the detected refrigerant temperature TS1, the smaller the continuous rated current value I45, and the lower the detected refrigerant temperature TS1, the larger the continuous rated current value I45. Note that if temperature changes in the refrigerant of the generator 2 can be ignored or to simplify the circuit, the continuous rated current value I45 may be a fixed value instead of equation (1).

[0124] The continuous rated current value I45 corresponds to a value that falls within the continuous rated current value of the power generation unit 80 in the graph shown in Fig. 2. For example, assume that a value equal to or less than the current value I300 is calculated as the continuous rated current value I45 within the usable power generation range (V100 to V200) of the power generation unit 80. In this case, the continuous rated current value I45 will always be within the continuous rated current value of the power generation unit 80 within the usable power generation range (V100 to V200). From the perspective of speeding up charging, it is desirable to calculate a larger continuous rated current value I45.

[0125] The power generation side current command value output circuit 40 also has a current squared time product calculation circuit 42 inside.

[0126] The current squared time product calculation circuit 42 has therein a square calculation circuit 55 (square calculation 55) and an integral calculation circuit 56. The square calculation circuit 55 receives the generator output current I2 detected by the current sensor IS1, calculates the square value of the generator output current I2, and outputs the squared value II2 to the integral calculation circuit 56.

[0127] The integration circuit 56, for example, numerically integrates the squared value II2 of the input current I2 to obtain an accumulation result ΣII2. For numerical integration, if the calculation period is "Δt," the integration circuit 56 multiplies the output of the squared value circuit 55 by "Δt" every calculation period Δt and accumulates the resulting value. Note that instead of simple product addition, numerical integration using a trapezoidal rule may be used. Starting from the time when the charging command C1 changes from "L" to "H," the integration circuit 56 integrates (accumulatively adds) the squared value II2 each time it receives it from the squared value circuit 55 to obtain the accumulation result ΣII2. In this way, the current squared-time product calculation circuit 42 calculates the accumulation result ΣII2, which is the current squared-time product of the output current of the generator 2. This accumulation result ΣII2 is output to the comparator 21.

[0128] The comparator 21 compares the accumulation result ΣII2 with the accumulation allowable value RΣ and outputs a comparison result signal S21 based on the comparison result. The comparison result signal S21 is "H" if {ΣII2≦RΣ} and "L" if {ΣII2>RΣ}.

[0129] In this way, the current squared time product calculation circuit 42 and the comparator 21 constitute an accumulation value determination circuit. The accumulation value determination circuit calculates the current squared time product of the generator output current I2, which is the generated current, at predetermined time intervals Δt, and outputs a comparison result signal S21 indicating accumulation excess ("L") when the accumulation result ΣII2, which is the accumulated value of the current squared time product, exceeds the accumulation allowable value RΣ. The comparison result signal S21 serves as the allowable value comparison signal.

[0130] The comparison result signal S21 output from the comparator 21 is output to the control terminal C of the selection switch 46, and is also output as an input signal to the AND gate G9.

[0131] The cumulative allowable value RΣ used by the comparator 21 is indicated by a set allowable value signal S43 output from the allowable value calculation circuit 43.

[0132] The allowable value calculation circuit 43 receives the detected refrigerant temperature TS1, calculates the cumulative allowable value RΣ based on the detected refrigerant temperature TS1, and outputs to the comparator 21 a set allowable value signal S43 indicating the calculated cumulative allowable value RΣ.

[0133] The allowable value calculation circuit 43 obtains the cumulative allowable value RΣ as follows: If the reference cumulative allowable value RΣ when the generator 2 is at the reference temperature TR2 is set to (0), the cumulative allowable value RΣ is calculated by the following formula (2).

[0134] RΣ=RΣ(0)-K2×(TS1−TR2)…(2) Note that "K2" is a proportional multiplier (positive value).

[0135] As shown in equation (2), the higher the detected refrigerant temperature TS1, the smaller the cumulative allowable value RΣ, and the lower the detected refrigerant temperature TS1, the larger the cumulative allowable value RΣ. The reference cumulative allowable value RΣ(0) is a value determined from the current-squared-hour integrated capacity of the generator 2. Note that if temperature changes in the generator's refrigerant can be ignored or to simplify the circuit, the cumulative allowable value RΣ may be a fixed value instead of equation (2).

[0136] Until the accumulation result ΣII2 of the squared values ​​II2 reaches the cumulative allowable value RΣ, no abnormality occurs in the generator 2 due to heat generation, and the power generating unit 80 can be used.

[0137] When the comparison result signal S21 received by the control terminal C is "H", the selection switch 46 connects the input terminal A to the output terminal D and outputs the short-time rated current value I44 as the selected rated current value I46. In other words, when the comparison result signal S21 is "H", the selection switch 46 is set to the high-speed charging mode.

[0138] When the comparison result signal S21 received by the control terminal C is "L", the selection switch 46 connects the input terminal B to the output terminal D and outputs the continuous rated current value I45 as the selected rated current value I46. In other words, when the comparison result signal S21 is "L", the selection switch 46 is set to the normal charging mode.

[0139] In this way, when the comparison result signal S21 of the comparator 21 indicates "L" (accumulation excess), the power generation side current command value output circuit 40 sets the continuous rated current value I45 to the selected rated current value I46.

[0140] The adder 49 receives the heater current I7 and the cooling device current I8, and outputs the sum of the current value of the heater current I7 and the current value of the cooling device current I8 as the auxiliary circuit current value I49.

[0141] The subtractor 48 receives the selected rated current value I46 and the auxiliary circuit current value I49, and outputs the current value obtained by subtracting the auxiliary circuit current value I49 from the selected rated current value I46 as the generator command current value AI2.

[0142] As described above, the generator-side current command value output circuit 40 outputs the generator-side command current value AI2 based on the selected rated current value I46 in the power generation operation of the power generation unit 80. The selected rated current value I46 is one of the continuous rated current value I45 and the short-time rated current value I44.

[0143] The auxiliary circuit current value I49 is equal to the heater current I7 while the heater 7 is performing the heating operation, and is equal to the cooling device current I8 while the cooling device 8 is performing the cooling operation. Note that the heating operation of the heater 7 and the cooling operation of the cooling device 8 are never performed simultaneously.

[0144] Therefore, during the period in which the heater 7 is performing the heating operation, the power generation command current value AI2 is a current value obtained by subtracting the current value of the heater current I7 from the selected rated current value I46. Also, during the period in which the cooling operation of the cooling device 8 is performing the cooling operation, the power generation command current value AI2 is a current value obtained by subtracting the current value of the cooling device current I8 from the selected rated current value I46.

[0145] The power generation side current command value output circuit 40 further includes a fast charge recovery circuit 41. The fast charge recovery circuit 41 includes, as its main components, a NOT gate G11, a timer circuit 51, a time judgment circuit 52, and a one-shot circuit 53. The configuration and operation of the fast charge recovery circuit 41 will be described below.

[0146] The NOT gate G11 receives the comparison result signal S21 and outputs a logic signal SG11 indicating the NOT operation result of the comparison result signal S21.

[0147] The timer circuit 51 (timer 51) counts time using the rising edge of the logic signal SG11 from “L” to “H” as a trigger, and outputs a count time CT51 to the time determination circuit 52.

[0148] The time determination circuit 52 compares the count time CT51 with the assumed cooling period To, and when the count time CT51 exceeds the assumed cooling period To, it drives the one-shot circuit 53 to generate an “H” one-shot pulse in the high-speed charging resumption signal S41 output from the one-shot circuit 53.

[0149] Meanwhile, the one-shot circuit 47 outside the fast charge recovery circuit 41 receives the charge command C1, and generates a one-shot pulse of "H" in the charge start signal S47, which is an output signal, when the charge command C1 rises from "L" to "H".

[0150] The OR gate G10 receives the high-speed charging restart signal S41 and the charging start signal S47, and outputs the OR operation result of the high-speed charging restart signal S41 and the charging start signal S47 as a logic signal SG10.

[0151] The integration circuit 56 receives the logic signal SG10, and when the logic signal SG10 is "H", resets the accumulation result ΣII2 to "0". The logic signal SG10 becomes "H" when a one-shot pulse of "H" occurs in at least one of the high-speed charging resumption signal S41 and the charging start signal S47.

[0152] Therefore, when the start of charging is instructed by the charging start signal S47 at "H" and when the resumption of fast charging is instructed by the fast charging resumption signal S41 at "H", the accumulation result ΣII2 of the integration calculation circuit 56 is reset to "0".

[0153] When the accumulation result ΣII2 is reset, the comparison result signal S21 output from the comparator 21 becomes "H", and therefore the short-time rated current value I44 is selected as the selected rated current value I46.

[0154] Returning to FIG. 5, the minimum value selection circuit 35, which is a charging current value determination circuit, receives the allowable AC current value AI1 and the power generation side command current value AI2, and outputs the current value that is the minimum of the allowable AC current value AI1 and the power generation side command current value AI2 as the determined charging current value DCI.

[0155] In this way, the minimum value selection circuit 35 functions as a charging current value determination circuit that determines the smaller of the allowable AC current value AI1 and the power generation command current value AI2 as the determined charging current value DCI.

[0156] The selection switch 36 receives the determined charging current value DCI at input terminal A, receives “0” at input terminal B, and receives logic signal SG5 at control terminal C. When the logic signal SG5 is “H”, the selection switch 36 connects the input terminal A to the output terminal D, and when the logic signal SG5 is “L”, the selection switch 36 connects the input terminal A to the output terminal D.

[0157] The logic signal SG5 becomes "H" when the charge completion signal S5 indicates "L" indicating that charging is not completed and the charge command C1 indicates "H" indicating that the charging operation is enabled. In other words, the logic signal SG5 becomes "H" while the charging operation is being performed.

[0158] The signal obtained from the output terminal D is the final charging current value SDC. Therefore, during the charging operation, the determined charging current value DCI is output as the final charging current value SDC.

[0159] The final charging current value SDC is added by an adder 37 with the auxiliary circuit current value I49, and the output thereof, a generator current command value S37, is subtracted by a subtracter 38 with the generator output current I2, and is then output as a control current value I38 to an excitation current command value calculation circuit 39. The control current value I38 is the difference between the generator current command value S37 and the generator current feedback value I2.

[0160] The excitation current command value calculation circuit 39 outputs a charging current command value C5 based on the control current value I38 to the excitation control device 4. Since the excitation current command value calculation circuit 39 operates as, for example, a PI circuit, the charging current command value C5 becomes an instruction content for making the generator output current I2 follow the generator current command value S37 based on the control current value I38.

[0161] Therefore, by outputting the charging current command value C5 to the excitation control device 4, the charging control circuit 5 can control the power generation operation of the power generation unit 80 so that the charging current output to the rechargeable battery unit 6 becomes the determined charging current value DCI.

[0162] (Charging Operation by Charging System 100) Fig. 7 is a graph showing a change in battery temperature over time during the charging operation of the charging system 100. Fig. 8 is a graph showing the open / closed states (ON, OFF) of the three switches SW1 to SW3 during the charging operation of the charging system 100. Fig. 9 is a graph showing a change in the final charging current value SDC over time during the charging operation. Fig. 10 is a graph showing a change in the charging current I6 and the generator output current I2 over time during the charging operation.

[0163] 7 to 10, the charging operation for the rechargeable battery unit 6 in the charging system 100 shown in Figures 1 to 6 will be described below. In the following description, the minimum battery temperature value Tmin and the maximum battery temperature value Tmax will be collectively referred to simply as "battery temperature T".

[0164] In the following description of the charging operation, the DC short-time rated current value DI44 is set to a value greater than the allowable charging current value IcLT5 and the DC auxiliary circuit current value DI49. The auxiliary circuit current value I49 is converted to a DC current value, which becomes the DC auxiliary circuit current value DI49.

[0165] On the other hand, the DC continuous rated current value DI45 is set to a value smaller than the allowable charging current value IcLT3. The heater 7 and the cooling device 8 are constant current loads, and the heater current I7 and the cooling device current I8 are each set to a value smaller than the continuous rated current value I45.

[0166] Before time t1, the charging command C1 indicates "L" to disable charging, and the battery temperature T of the rechargeable battery unit 6 is between battery temperature T2 and battery temperature T3, and there is no variation in battery temperature among the multiple battery cells in the rechargeable battery unit 6.

[0167] That is, it is assumed that sufficient time has passed since the previous charge or discharge at time t1. Also, all of the switches SW1 to SW3 are in the "open state" (OFF state).

[0168] The current value of the cooling device current I8 detected by the current sensor IS3, which is a cooling device current sensor, and the current value of the heater current I7 detected by the current sensor IS4, which is a heater current sensor, are both "0".

[0169] At time t1, the charging command C1 rises to "H" to indicate that the charging operation is enabled, which triggers the charging system 100 to start the charging operation.

[0170] When the charge command C1 rises to "H", a one-shot pulse of "H" is generated in the charge start signal S47 of the one-shot circuit 47 in the power generation side current command value output circuit 40 of the charge control circuit 5.

[0171] As a result, the OR gate G10 outputs a logic signal SG10 of "H" to the integration circuit 56, causing the integration circuit 56 to reset the accumulation result ΣII2 to "0".

[0172] Therefore, the selection switch 46 selects the short-time rated current value I44 applied to the input terminal A as the selected rated current value I46. That is, at time t1, the high-speed charging mode is entered.

[0173] In this way, the power generation side current command value output circuit 40 sets the short-time rated current value I44 as the selected rated current value I46 at the start of charging the rechargeable battery unit 6. In other words, the high-speed charging mode is set at the start of charging.

[0174] On the other hand, because the battery temperature T of the rechargeable battery unit 6 is equal to or lower than the battery temperature T4, the logic signal SG9 of the AND gate G9 becomes "H", and the switch operation signal S3 output from the AND gate G8 becomes "H", so that the switch SW3 is in the "closed state" (ON state) as shown in Fig. 8. As a result, the heater 7 performs a heating operation from time t1.

[0175] As shown in Figure 7, the battery temperature T rises from time t1 to time t2. As shown in Figures 9 and 10, the final charging current value SDC (determined charging current value DCI) and the generator output current I2 also rise from time t1 to time t2. Because part of the generator output current I2 becomes the heater current I7, the charging current I6 becomes slightly lower than the generator output current I2.

[0176] After time t2, the minimum battery temperature value Tmin exceeds the battery temperature T4. Then, the logic signal SG9 changes from "H" to "L", and the switch operation signal S3 changes from "H" to "L". As a result, the switch SW3 is in the "open state" (OFF state) as shown in Figure 8. As a result, the heater 7 ends its heating operation.

[0177] At time t3, battery temperature T approaches battery temperature T5, so that the final charging current value SDC and generator output current I2 reach nearly their maximum values ​​at time t3, as shown in Figures 9 and 10. Meanwhile, the current value of heater current I7 becomes "0," so that charging current I6 and generator output current I2 have the same current value.

[0178] At time t4, the maximum battery temperature Tmax exceeds the battery temperature T6. Then, the switch operation signal S2, which is the output of the AND gate G6, becomes "H", and as a result, the switch SW2 is in the "closed state" as shown in FIG. 8. As a result, the cooling device 8 performs a cooling operation. Note that in this explanation, it is assumed that the battery temperature T continues to rise until time t5 due to the heat capacity of the rechargeable battery unit 6 or the response of the cooling device 8.

[0179] At time t5, the battery temperature T reaches approximately its maximum value, and after time t5, the battery temperature T decreases due to the cooling operation of the cooling device 8.

[0180] After time t6, the maximum battery temperature Tmax falls below the battery temperature T6. Then, the switch operation signal S2 changes from "H" to "L", and as a result, the switch SW2 enters the "open state" as shown in Figure 8. As a result, the cooling device 8 ends its cooling operation. Note that during the period from time t4 to t6, part of the generator output current I2 becomes the cooling device current I8, and a difference occurs between the generator output current I2 and the charging current I6 by the amount of the cooling device current I8 consumed.

[0181] Thereafter, at time t7, the minimum battery temperature Tmin drops to battery temperature T5, and at time t8, the maximum battery temperature Tmax drops to battery temperature T5.

[0182] As shown in FIG. 9, the final charging current value SDC remains relatively large after time t8, so the battery temperature T rises again.

[0183] At time t9, the accumulation result ΣII2 of the integration circuit 56 exceeds the accumulation allowable value RΣ. This causes the comparison result signal S21 to change from "H" to "L." Therefore, the selection switch 46 selects the continuous rated current value I45 applied to the input terminal B as the selected rated current value I46.

[0184] That is, the charging mode switches from the high-speed charging mode to the normal charging mode starting from time t9. Therefore, as shown in Figures 9 and 10, the final charging current value SDC and the generator output current I2 (charging current I6) drop sharply at time t9. Meanwhile, as shown in Figure 7, the battery temperature T also drops after time t9. As described above, during the period from time t1 to time t9, the rechargeable battery unit 6 is charged according to the allowable charging current determined from the temperature (TS61 or TS62) detected by the temperature sensor 61 or 62 provided in the rechargeable battery unit 6.

[0185] At time t10, the minimum battery temperature value Tmin falls below the battery temperature T3, so the comparison result signal S25 changes from "L" to "H", and the switch operation signal S3, which is the output signal of the AND gate G8, changes from "L" to "H". As a result, as shown in Fig. 8, the switch SW3 is again in the "closed state", and the heater 7 performs the heating operation again.

[0186] Therefore, after time t10, part of the generator output current I2 becomes the heater current I7, and a difference occurs between the generator output current I2 and the charging current I6 due to the amount of the heater current I7 consumed.

[0187] At time t11, the charging voltage V6 of the rechargeable battery unit 6 reaches the charging determination voltage, entering a fully charged state, and the charging completion signal S5 of "H" is output from the charge amount determination circuit 10, completing the charging operation. In other words, after time t9, the charging current determined by the continuous rating of the generator 2 is smaller than the allowable charging current determined from the temperature detected by the temperature sensor 61 or 62 provided in the rechargeable battery unit 6, and therefore the rechargeable battery unit 6 is charged within the range of the current determined by the continuous rating of the generator 2.

[0188] In this way, the charging operation for the rechargeable battery unit 6 in the charging system 100 is carried out under the control of the charging control circuit 5.

[0189] If time t20, which is the time after the expected cooling period To has elapsed since time t10, arrives earlier than time t11, a one-shot pulse of “H” is generated in the fast charging resumption signal S41 of the fast charging recovery circuit 41, and the accumulation result ΣII2 of the integration calculation circuit 56 is reset to “0”.

[0190] As a result, the comparison result signal S21 changes from "L" to "H", and the short-time rated current value I44 is selected as the selected rated current value I46 by the selection switch 46. That is, starting from time t20, the normal charging mode is switched back to the high-speed charging mode.

[0191] Furthermore, if the state of charge of the rechargeable battery unit 6 is already relatively high, at about 80%, when the charging operation starts at time t1, it is possible that charging of the rechargeable battery unit 6 will be completed by time t9. In this case, the charging operation of the rechargeable battery unit 6 will be completed in the high-speed charging mode only.

[0192] The above-mentioned assumed cooling period To is the time it is assumed that power generation unit 80, which has been used so that the cumulative result ΣII2 reaches cumulative allowable value RΣ, will cool down to a temperature at which it can be operated in high-speed charging mode again, and will be able to operate again at the predetermined short-time rating set in short-time rated current setting circuit 44 up to the allowable value in current squared hours set in allowable value calculation circuit 43. The assumed cooling period To is selected taking into consideration the heat dissipation and cooling characteristics of power generation unit 80, the cooling mechanism (not shown in FIG. 1) provided in power generation unit 80, the heat capacity of generator 2, etc.

[0193] Note that instead of the timer circuit 51 and the time determination circuit 52, a temperature determination circuit may be used that directly measures and determines the winding temperature, iron core temperature, etc. of the generator 2. The temperature determination circuit is a circuit that generates an "H" one-shot pulse in the high-speed charging resumption signal S41 output from the one-shot circuit 53 when the winding temperature or iron core temperature of the generator 2 drops to a predetermined resumption temperature.

[0194] (effect) The charging control circuit 5 in the charging system 100 of this embodiment controls the power generation operation of the power generation unit 80 so that the charging current I6 output to the rechargeable battery unit 6 becomes the determined charging current value DCI (=final charging current value SDC). The determined charging current value DCI selected by the minimum value selection circuit 35 does not exceed the allowable AC current value AI1, which is the allowable charging current value calculated based on the battery temperature T.

[0195] Therefore, the charging system 100 of this embodiment takes into account changes in the battery temperature T of the rechargeable battery unit 6 and can output a charging current I6 to the rechargeable battery unit 6 so that the determined charging current value DCI is always less than or equal to the allowable AC current value AI1.

[0196] As a result, the charging system 100 of this embodiment can always output to the rechargeable battery unit 6 a charging current I6 of the determined charging current value DCI appropriate for the rechargeable battery unit 6 under an assumed temperature environment.

[0197] In the charging system 100 of this embodiment, the power generation side current command value output circuit 40 is set to a high-speed charging mode in which the selected rated current value I46 is set to the short-time rated current value I44 when starting the charging operation of the rechargeable battery unit 6, thereby enabling high-speed charging of the rechargeable battery unit 6.

[0198] Furthermore, when the comparison result signal S21, which is an allowable value comparison signal, indicates cumulative excess ("L"), the power generation side current command value output circuit 40 switches from the high-speed charging mode to the normal charging mode in which the selected rated current value I46 is set to the continuous rated current value I45, thereby preventing abnormalities caused by heat generation in the power generation unit 80.

[0199] The charging control circuit 5 in the charging system 100 of this embodiment can quickly raise the battery temperature T of the rechargeable battery unit 6 toward the charging peak temperature, battery temperature T5, by causing the heater 7 to perform a heating operation when the battery temperature T is below the heating reference temperature (battery temperature T3 or battery temperature T4).

[0200] As a result, the charging system 100 of this embodiment can increase the current value of the allowable charging current IcL early on, and accordingly increase the determined charging current value DCI, thereby enabling the rechargeable battery unit 6 to be charged at high speed.

[0201] The charging control circuit 5 in the charging system 100 of this embodiment can suppress the phenomenon in which the battery temperature T exceeds the cooling reference temperature, battery temperature T6, by causing the cooling device 8 to perform a cooling operation when the battery temperature T of the rechargeable battery unit 6 is equal to or higher than the cooling reference temperature, battery temperature T6.

[0202] As a result, the charging system 100 of this embodiment can minimize the time period during which the battery temperature T exceeds the battery temperature T6, and can charge the rechargeable battery unit 6 in a relatively mild temperature environment.

[0203] The charge control circuit 5 in the charging system 100 of this embodiment causes the heater 7 to perform a heating operation when the minimum of the detected battery temperatures TS61 and TS62, which are multiple battery temperatures, is equal to or lower than the heating reference temperature (battery temperature T3 or battery temperature T4). Therefore, the charge control circuit 5 can control the heating operation of the heater 7 by prioritizing that the detected battery temperatures TS61 and TS62 all reach the heating reference temperature.

[0204] The charge control circuit 5 in the charging system 100 of this embodiment causes the cooling device 8 to perform a cooling operation when the maximum value of the detected battery temperatures TS61 and TS62, which are multiple battery temperatures, is equal to or higher than the battery temperature T6, which is the cooling reference temperature. Therefore, the charge control circuit 5 can control the cooling operation of the cooling device 8 by prioritizing at least one of the detected battery temperatures TS61 and TS62 reaching the battery temperature T6.

[0205] As a result, the charging system 100 of this embodiment can maintain the detected battery temperatures TS61 and TS62 near the battery temperature T5, which is the charging peak temperature, and can maintain the current value of the allowable charging current IcL of the rechargeable battery unit 6 high.

[0206] In the charging control circuit 5 of the charging system 100 of this embodiment, when in a high-speed charging mode in which the selected rated current value I46 is the short-time rated current value I44, the heating reference temperature is set to a second heating reference temperature, battery temperature T4, which is higher than the first heating reference temperature, battery temperature T3.

[0207] Therefore, when the charging system 100 of this embodiment charges the rechargeable battery unit 6 at high speed in the high-speed charging mode, the heater 7 performs a heating operation until the battery temperature reaches T4, thereby increasing the allowable charging current IcL of the rechargeable battery unit 6 at an early stage and charging the rechargeable battery unit 6 at a higher speed.

[0208] The charge control circuit 5 in the charging system 100 of this embodiment controls the heating operation of the heater 7 and the cooling operation of the cooling device 8, and sets the power generation command current value AI2 as follows: During the period in which the heater 7 is performing the heating operation, the power generation command current value AI2 is set to a current value obtained by subtracting the current value of the heater current I7 from the selected rated current value I46, and during the period in which the cooling operation of the cooling device 8 is performing the cooling operation, the power generation command current value AI2 is set to a current value obtained by subtracting the current value of the cooling device current I8 from the selected rated current value I46.

[0209] Therefore, the charging system 100 of this embodiment can perform the heating operation of the heater 7 and the cooling operation of the cooling device 8 using the power generated by the power generation unit 80, and can output a charging current I6 of an appropriate determined charging current value DCI to the rechargeable battery unit 6.

[0210] It should be noted that the present disclosure allows for appropriate modifications and omissions of the embodiments within the scope of the disclosure. In the present embodiment, power for the heater 7 and the cooling device 8 is supplied from the generator 2, but a modified configuration is also possible in which power for the heater 7 and the cooling device 8 is supplied from a source other than the generator 2. In the case of a modified configuration, in the charge control circuit 5 shown in Figures 5 and 6, the subtraction unit 48, the addition unit 37, and the addition unit 49 can be omitted, the selected rated current value I46 can be used instead of the generator-side command current value AI2, and the final charging current value SDC can be used instead of the generator current command value S37. [Explanation of symbols]

[0211] 1 Prime mover 2. Generator 3 rectifier 4 Excitation control device 5. Charging control circuit 6 Rechargeable battery section 7 Heater 8 Cooling device 10 Charge amount judgment circuit 11 Average value calculation circuit 12 Maximum value selection circuit 13 Minimum value selection circuit 15 Refrigerant temperature sensor 20 Comparator Group 21~26 Comparator 31, 32 Allowable charging current calculation circuit 33,35 Minimum value selection circuit 34 Conversion circuit 36,46 selection switch 37,49 Addition section 38,48 Subtraction section 39 Excitation current command value calculation circuit 40 Power generation side current command value output circuit 41 Fast charge recovery circuit 42 Current squared time product calculation circuit 43 Tolerance calculation circuit 44 Short-time rated current setting circuit 45 Continuous rated current calculation circuit 61,62 Temperature sensor G1, G3 NOT gate G2, G7, G10 OR gate G4~G6,G8,G9 AND gate IS1~IS4 Current sensors SW1~SW3 switches VS1, VS2 voltage sensors

Claims

1. A rechargeable battery unit that can be charged; a battery temperature sensor that detects the temperature of the rechargeable battery unit to obtain a detected battery temperature; a power generation unit that performs a power generation operation and outputs a charging current based on the generated power obtained by the power generation operation to the rechargeable battery unit; a charge control circuit that receives the detected battery temperature and controls the power generation operation of the power generation unit; The charge control circuit an allowable charging current value calculation circuit that calculates an allowable charging current value for the rechargeable battery unit based on the detected battery temperature; a power generation-side current command value output circuit that outputs a power generation-side command current value based on a selected rated current value in the power generation operation, the selected rated current value being one of a continuous rated current value and a short-time rated current value that exceeds the continuous rated current value, The charge control circuit a charging current value determination circuit that determines the smaller of the allowable charging current value and the power generation command current value as a determined charging current value; the charging control circuit controls the power generation operation of the power generation unit so that the charging current output to the rechargeable battery unit becomes the determined charging current value. Charging system.

2. 2. The charging system according to claim 1, a power generation side current sensor for detecting a generated current of the power generation unit; The power generation side current command value output circuit an accumulation value determination circuit that calculates a current squared time product of the generated current and outputs a tolerance value comparison signal indicating an accumulation excess when the accumulation result, which is the current squared time product, exceeds an accumulation tolerance value; When a charging operation of the rechargeable battery unit is started, the short-time rated current value is set to the selected rated current value, When the tolerance comparison signal indicates the cumulative excess, the continuous rated current value is set to the selected rated current value. Charging system.

3. 3. The charging system according to claim 2, a heater that performs a heating operation to heat the rechargeable battery unit; a cooling device that performs a cooling operation to cool the rechargeable battery unit, the allowable charging current value in the rechargeable battery unit has a temperature characteristic in which the allowable charging current value is maximum at a peak charging temperature, the allowable charging current value increases in a first temperature range below the peak charging temperature, and the allowable charging current value decreases in a second temperature range above the peak charging temperature; The charge control circuit a heating control operation for causing the heater to perform the heating operation when the detected battery temperature is equal to or lower than a heating reference temperature, and a cooling control operation for causing the cooling device to perform the cooling operation when the detected battery temperature is equal to or higher than a cooling reference temperature; the heating reference temperature is lower than the peak charging temperature, and the cooling reference temperature is higher than the peak charging temperature; Charging system.

4. 4. The charging system according to claim 3, the rechargeable battery unit includes a plurality of battery cells, the battery temperature sensor includes a plurality of battery temperature sensors, and the detected battery temperatures include a plurality of detected battery temperatures detected by the plurality of battery temperature sensors; the heating control operation is an operation of causing the heater to perform the heating operation when the minimum value of the plurality of detected battery temperatures is equal to or lower than the heating reference temperature; the cooling control operation is an operation of causing the cooling device to perform the cooling operation when the maximum value of the plurality of detected battery temperatures is equal to or higher than the cooling reference temperature. Charging system.

5. 5. The charging system according to claim 4, the heating reference temperature includes a first heating reference temperature and a second heating reference temperature, the second heating reference temperature being higher than the first heating reference temperature; when the selected rated current value is the continuous rated current value, the heating reference temperature is set to the first heating reference temperature; When the selected rated current value is the short-time rated current value, the heating reference temperature is set to the second heating reference temperature. Charging system.

6. The charging system according to any one of claims 3 to 5, the heating operation of the heater and the cooling operation of the cooling device are performed by the power generated by the power generation unit; The charging system includes: a heater current sensor for detecting a current supplied to the heater to obtain a heater current; a cooling device current sensor for detecting a current supplied to the cooling device to obtain a cooling device current; The charge control circuit further receiving the heater current and the cooling device current; during the execution period of the heating operation of the heater, the power generation command current value is a current value obtained by subtracting the current value of the heater current from the selected rated current value, During the execution period of the cooling operation of the cooling device, the power generation command current value is a current value obtained by subtracting the current value of the cooling device current from the selected rated current value. Charging system.

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