Activation apparatus and activation method

Abstract

To appropriately estimate precharge completion of a first system on a second system side when the second system is started by power from the first system.SOLUTION: An activation apparatus for a second system 200 that is activated by receiving power supply from a first system 100, the first system 100 and the second system 200 being connected by a second power line DL2 such that the second system 200 and a load 110 are in parallel, the activation apparatus including a sensor 260 that measures a voltage of a precharge circuit of the first system 100 via a first power line DL1 and the second power line DL2, and a control unit 240 that instructs an activation attempt of the second system 200 when the voltage measured by the sensor 260 satisfies a first predetermined condition while the precharge circuit is performing precharging, and estimates completion of the precharging when the voltage measured by the sensor 260 satisfies a second predetermined condition after the activation attempt.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a startup device and a startup method for a second system that is separate from a first system and that is started using power from the first system. [Background technology]

[0002] As a technology of this type, a power control device mounted on an electric vehicle is known (see, for example, Patent Document 1). In this power control device, completion of pre-charging is detected when the rate of change of the pre-charge voltage of the battery system falls below a predetermined value. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-120866 Summary of the Invention [Problem to be solved by the invention]

[0004] However, when an electric vehicle is equipped with a system (hereinafter referred to as a second system) independent of a battery system (hereinafter referred to as a first system), it becomes necessary for the second system to correctly determine the completion of pre-charging in the first system. More specifically, if the second system erroneously determines the completion of pre-charging in the first system, it may attempt to start the second system before pre-charging is complete. In this case, it is expected that it will be difficult to start the second system because the power supply from the first system will be insufficient before pre-charging is complete. That is, the conventional technology does not anticipate combination with the second system, and therefore cannot be applied as is to, for example, a fuel cell vehicle in which the second system, such as a fuel cell system, is combined with the first system. In other words, the conventional technology cannot correctly determine whether pre-charging is complete unless communication is used between the second system and the first system. The fuel cell system, which is an example of the second system, is considered to be one effective means for reducing adverse effects on the global environment, and therefore the above-mentioned issue is extremely important. [Means for solving the problem]

[0005] One aspect of the present invention is a startup device for a second system, different from the first system, which is started by receiving power from a first system including a battery, a load that receives power from the battery, and a precharge circuit provided on a first power line connecting the battery and the load, wherein the first system and the second system are connected by a second power line so that the second system and the load are in parallel, and the startup device includes a sensor that measures the voltage of the precharge circuit of the first system via the first power line and the second power line, and a control unit that instructs a startup attempt of the second system when the voltage measured by the sensor while precharging is being performed by the precharge circuit satisfies a first predetermined condition, and that estimates the completion of precharging when the voltage measured by the sensor after the startup attempt satisfies a second predetermined condition. Another aspect of the present invention is a startup method for a second system, different from the first system, which is started by receiving power supply from a first system including a battery, a load that receives power supply from the battery, and a precharge circuit provided on a first power line connecting the battery and the load, wherein the first system and the second system are connected by a second power line so that the second system and the load are in parallel, and the startup method includes the steps of: acquiring a detection signal from a sensor that measures the voltage of the precharge circuit of the first system via the first power line and the second power line while precharging is being performed by the precharge circuit; instructing the second system to attempt startup when the voltage based on the detection signal acquired from the sensor satisfies a first predetermined condition; and estimating completion of precharging when the voltage based on the detection signal acquired from the sensor after the startup attempt satisfies a second predetermined condition. [Effects of the Invention]

[0006] According to the present invention, when a second system is started up using power from a first system, the second system can appropriately estimate the completion of precharging of the first system. [Brief explanation of the drawings]

[0007] [Figure 1] FIG. 1 is a schematic configuration diagram showing an example of an overall system. [Figure 2A] FIG. 2 is a schematic diagram illustrating a precharge circuit in a BATT & load system. [Figure 2B] FIG. 2 is a schematic diagram illustrating a precharge circuit in a BATT & load system. [Figure 2C] FIG. 2 is a schematic diagram illustrating a precharge circuit in a BATT & load system. [Figure 3A] FIG. 4 is a schematic diagram illustrating a change in voltage V2 during a precharge operation. [Figure 3B] FIG. 4 is a schematic diagram illustrating a change in voltage V2 during a precharge operation. [Figure 4] 10 is a flowchart illustrating an example of a startup process executed by the FCMGECU. DETAILED DESCRIPTION OF THE INVENTION

[0008] <Summary> An overall system including a first system and a second system according to an embodiment of the invention drives a traction motor as a load using at least one of electric power (referred to as FC power) generated and output by a fuel cell (Fuel Cell: hereinafter sometimes referred to as FC) of the second system and electric power (referred to as battery power) stored in a secondary battery of the first system. Also, electric power generated by the traction motor during regeneration (referred to as regenerative power) is stored in the secondary battery of the first system.

[0009] The overall system normally controls the charging and discharging of the secondary battery of the first system to drive the load using both the FC power from the second system and the battery power of the first system, thereby reducing the consumption of hydrogen as fuel. Furthermore, when power generation by the fuel cell is not possible, such as before the start-up of the second system, the overall system controls the discharging of the secondary battery of the first system to drive the load using only the battery power. Details of this overall system will be described with reference to the drawings.

[0010] <Overall system> FIG. 1 is a schematic diagram showing an example of an overall system 1 according to an embodiment of the invention. As an example, a first system is applied to an electric vehicle driven by a motor 120. In this embodiment, the first system has a battery (hereinafter sometimes referred to as BATT) and load system 100. Also, in this embodiment, the second system has an FC system 200.

[0011] The BATT & load system 100 includes at least a driving motor 120, an inverter (INV) 110, a BATT system (electricity storage device) 150, a DC / DC converter 130, a contactor (CNT) unit 140, and an ECU (Electronic Control Unit) 160.

[0012] The FC system 200 includes at least an FC stack 210, a voltage control unit (hereinafter referred to as a converter (CONV)) 220, an auxiliary device 230, an FCMGECU 240, a contactor (CNT) unit 250, and a voltage sensor 260. The FCMGECU 240 and the voltage sensor 260 also function as start-up devices for the FC system 200.

[0013] The BATT&load system 100 and the FC system 200 are connected via a DC link DL2. In an embodiment, among a pair of power lines of a positive electrode and a negative electrode that supply battery power from the BATT system 150 included in the BATT&load system 100, the power line outside the BATT&load system 100 is called the DC link DL2, and the power line inside the BATT&load system 100 is called the DC link DL1. The FC system 200 is connected in parallel to the inverter 110 as a load with respect to the BATT system 150. Note that the DC voltage supplied from the FC system 200 to the BATT&load system 100 via the DC link DL2 is called the FC system voltage. Also, the DC voltage supplied from the BATT system 150 to the inverter 110 and the FC system 200 via the DC links DL1 and DL2 is called the battery voltage.

[0014] <BATT&load system> The configuration of the BATT&load system 100 will be briefly described. (Inverter) The inverter 110 is, for example, a bidirectional DC voltage / AC voltage converter. The DC side terminals of the inverter 110 are connected to the DC link DL1. The AC side terminals of the inverter 110 are connected to the motor 120. In the BATT&load system 100, the contactor unit 140 and the DC / DC converter 130 are connected to the DC link DL1. The inverter 110 converts a DC voltage into a three-phase AC voltage and supplies it to the motor 120. Also, the inverter 110 converts the AC voltage generated by the regenerative operation of the motor 120 into a DC voltage and outputs it to the DC link DL1. The voltage obtained by the regenerative operation is called the regenerative voltage. Note that a capacitor 135 (FIGS. 2A to 2C) is provided inside the inverter 110 so as to connect between the power lines of the positive electrode and the negative electrode.

[0015] (Motor) The motor 120 is, for example, a three-phase AC motor. A rotor of the motor 120 is connected to drive wheels (not shown). The motor 120 outputs drive force to the drive wheels using at least one of FC power supplied from the FC system 200 and battery power stored in the BATT system 150 (power running operation). The motor 120 also generates power using the kinetic energy of the electric vehicle when the electric vehicle decelerates (regenerative operation).

[0016] (DC / DC converter) DC / DC converter 130 is configured, for example, by a step-down DC voltage converter, and converts the FC system voltage of several hundred volts DC, the battery voltage, and the regenerative voltage into a voltage (for example, 12 V or 24 V DC) required by accessories including ECU 160. The accessories to which DC / DC converter 130 supplies power are electrical components that do not directly affect power generation, driving, etc. Power from DC / DC converter 130 is also supplied to FCMGECU 240 of FC system 200. In order to enable power supply to ECU 160 and the like even before DC / DC converter 130 starts operating, an auxiliary battery (DC 12V or 24V) (not shown) may be provided in addition to DC / DC converter 130. In this case, the auxiliary battery is charged when DC / DC converter 130 starts operating.

[0017] (contactor unit) The contactor unit 140 connects or disconnects the BATT system 150 and the DC link DL1. FIG. 2A is a schematic diagram illustrating a precharge circuit in the BATT & load system 100. The internal configuration of the contactor unit 140 will be described with reference to FIG. 2A. In FIG. 2A, a switch (hereinafter referred to as a main contactor) 143 made of an electromagnetic switch is provided on a DC link DL1 connected to the positive electrode of the secondary battery of the BATT system 150. Also, a switch (hereinafter referred to as a main contactor) 144 made of an electromagnetic switch is provided on the DC link DL1 connected to the negative electrode of the secondary battery of the BATT system 150. Here, the positive side of the DC link DL1 is represented as DL1(P), and the negative side is represented as DL1(N). Furthermore, a precharge circuit 145 is provided in parallel with the main contactor 143. The precharge circuit 145 includes a resistor 141 and a switch (hereinafter referred to as a precharge contactor) 142 made up of an electromagnetic switch. The commands to connect and disconnect the main contactors 143 and 144 of the contactor unit 140 and the precharge contactor 142 are sent from the ECU 160, for example. In the embodiment, the BATT system 150 side of the contactor unit 140 may be referred to as the primary side, and the inverter 110 side of the contactor unit 140 may be referred to as the secondary side. Battery power output from the BATT system 150 is output to the DC link DL1 via the contactor unit 140 while the main contactors 143 and 144 are connected. Regenerative power output from the inverter 110 is supplied to the BATT system 150 via the contactor unit 140 while the main contactors 143 and 144 are connected.

[0018] (battery system) As an example, the BATT system 150 stores (charges) regenerated power obtained by the regenerative operation of the motor 120 or FC power obtained by the power generation operation of the FC system 200 in a secondary battery, and discharges the power from the secondary battery to run the electric vehicle and operate the auxiliary machinery. As an example, the BATT system 150 includes a lithium ion battery or the like as the secondary battery. The BATT system 150 detects the current value, voltage value, and temperature of the secondary battery using a group of sensors (not shown), and calculates the SOC (State Of Charge; also referred to as the battery charging rate) of the secondary battery. A signal indicating the calculated SOC is output to the ECU 160.

[0019] The ECU 160 controls each part of the BATT & load system 100. The ECU 160 determines the required load based on, for example, the state of the BATT system 150 and the state of the motor 120, as well as inputs (load requests) from various switches and sensors (not shown). The ECU 160 then arbitrates and determines the allocation (sharing) of the load to be borne by the BATT system 150 and the load to be borne by the motor 120 as a regenerative power source, and sends instructions to the motor 120, the inverter 110, the BATT system 150, etc.

[0020] <FCシステム> The configuration of the FC system 200 will be briefly described. (FC stack) The FC stack 210 generates electricity by reacting hydrogen contained in the fuel gas as fuel with oxygen contained in the air as an oxidant. In this embodiment, the FC power generated by the FC stack 210 and boosted by the converter 220 is output to the DC link DL2 via the contactor unit 250. As a result, the FC power output from the FC system 200 is supplied to the motor 120 via the inverter 110, and to the BATT system 150 via the contactor unit 140.

[0021] (converter) The converter 220 has a step-up DC voltage converter. As an example, the converter 220 controls the FC current output from the FC system 200 while stepping up the power generation voltage PGV output from the FC stack 210 to a target voltage (referred to as TV). For example, by setting a target voltage TV higher than the voltage (referred to as PTV) output from the FC system 200, the FC current may be changed according to the voltage difference between the target voltage TV and the voltage PTV. The FCMGECU 240 may estimate the remaining capacity of the secondary battery of the BATT system 150 from the voltage supplied from the BATT & load system 100, for example, and determine the target voltage TV based on this estimated value.

[0022] (auxiliary equipment) The auxiliary machine 230 is, for example, an air pump or the like that is driven and controlled by the FCMGECU 240. The FC system 200 compresses air taken in from the outside using the air pump. The compressed air is used for power generation in the FC stack 210. A heater for heating gas or the FC stack 210 in cold regions may be added as an auxiliary device 230. As the power consumed by the auxiliary device 230, battery power from the BATT & load system 100 is supplied via the DC link DL2 while the contactor unit 250 (described later) is connected. This power can be supplied even before the FC system 200 is started (in other words, before power generation starts). Once the FC system 200 is operating (in other words, during power generation), FC power can be supplied to the auxiliary device 230. It should be noted that the auxiliary device 230 is different from the above-mentioned auxiliary device that operates on 12V or 24V DC.

[0023] (FCMGECU) The FCMGECU 240 controls each part of the FC system 200. As an example, while the FC system 200 is operating (in other words, while power is being generated), the FCMGECU 240 controls power generation by the FC stack 210, voltage boost by the converter 220, operation of the auxiliary equipment 230, connection by the contactor unit 250, etc., based on the remaining charge of the secondary battery of the BATT system 150 estimated as described above. The FCMGECU 240 in this embodiment does not communicate with the BATT & load system 100, and therefore is not notified by the BATT & load system 100 of the completion of the precharge operation in the BATT & load system 100. Therefore, when starting up the FC system 200 as a startup device, the FCMGECU 240 estimates the completion of the precharge operation in the BATT & load system 100 and then starts up the FC system 200. That is, while precharge is being performed in the BATT & load system 100, if a voltage measured by a voltage sensor 260 (described later) satisfies a first predetermined condition, the FCMGECU 240 instructs a startup attempt of the FC system 200. If the voltage measured by the voltage sensor 260 after the startup attempt satisfies a second predetermined condition, the FCMGECU 240 determines that precharge of the BATT & load system 100 has been completed and permits startup of the FC system 200. The startup attempt refers to having the FC system 200 consume battery power from the BATT & load system 100 before starting up the FC system 200. The FCMGECU 240 is not limited to being composed of only one control unit, but may also be composed of multiple control units, such as a control unit for power generation control of the FC stack 210, a control unit for starting up the FC system 200, or a control unit for the converter 220.

[0024] (contactor unit) The contactor unit 250 is provided on the output side of the converter 220. That is, although not shown in the figure, the contactor unit 250 has contactors each made up of an electromagnetic switch provided on the positive power line of the DC link DL2 and on the negative power line of the DC link DL2. For example, the FCMGECU 240 sends a command to connect and disconnect the contactor unit 250. With the contactor unit 250 connected, the FC power is supplied to the BATT & load system 100 via the DC link DL2.

[0025] (voltage sensor) The voltage sensor 260 measures the voltage between the positive and negative power lines of the DC link DL2. The voltage measured by the voltage sensor 260 when the FC system 200 is operating (in other words, generating power) corresponds to the FC system voltage output from the FC system 200. Furthermore, the voltage measured by the voltage sensor 260 when the contactor unit 250 is disconnected before the FC system 200 is started (in other words, before power generation starts) corresponds to the voltage at the DC side terminal of the inverter 110 of the BATT & load system 100. Therefore, the voltage measured by the voltage sensor 260 while the BATT & load system 100 is performing a precharge operation substantially corresponds to the voltage (referred to as V2) of the capacitor 135 provided in the inverter 110.

[0026] In this embodiment, the FCMGECU 240, which serves as a startup device for the FC system 200, estimates (may also be called a determination) the completion of pre-charging of the BATT & load system 100 before starting up the FC system 200 (in other words, before starting power generation). When the FCMGECU 240 estimates the completion of pre-charging, it permits the startup of the FC system 200.

[0027] <Precharge> First, a description will be given of the precharge operation of the BATT & load system 100. Figures 2A, 2B, and 2C are schematic diagrams illustrating a precharge circuit in the BATT & load system 100.

[0028] As shown in FIG. 2A, when the electric vehicle is stopped (an ignition switch (which may also be called a power switch) not shown is off), the main contactor (positive side) 143 and main contactor (negative side) 144 of the contactor unit 140, and the precharge contactor 142 of the precharge circuit 145 are disconnected (off). At this time, in the FC system 200, power generation by the FC stack 210 is stopped, and the contactors on the positive and negative power lines of the contactor unit 250 are disconnected (off).

[0029] When the driver turns on the ignition switch (not shown) of the electric vehicle, the ECU 160 of the BATT & load system 100 connects (ON) the main contactor (negative side) 144 of the contactor unit 140 and connects (ON) the precharge contactor 142 of the precharge circuit 145, as shown in FIG. 2B, to start charging the capacitor 135. At this time, the resistor 141 provided in the precharge circuit 145 limits the inrush current flowing through the precharge circuit 145. Then, when the capacitor 135 is charged, the ECU 160 connects (ON) the main contactor (positive electrode side) 143 and disconnects (OFF) the precharge contactor 142, as shown in FIG. 2C.

[0030] <Precharge completion estimation> Next, the estimation of pre-charge completion from the FC system 200 will be described. Figures 3A and 3B are schematic diagrams illustrating changes in voltage V2 of capacitor 135 during pre-charge operation. The curves in the upper graphs in Figures 3A and 3B each show changes in voltage V2 over time. The curves in the lower graphs in Figures 3A and 3B each show the time derivative (dV2 / dt) of voltage V2 over time. In FIG. 3A (first example), the SOC of the secondary battery of the BATT system 150 is higher than that in FIG. 3B (second example), so the time from start to completion of the precharge operation is shorter.

[0031] (Example 1) In FIG. 3A, the period up to time ta corresponds to the time when the electric vehicle is stopped (an ignition switch, not shown, is off) (FIG. 2A). When the driver turns on the ignition switch (not shown), ECU 160 connects (turns on) main contactor (negative side) 144 and pre-charge contactor 142 of contactor unit 140 at time ta (FIG. 2B). This starts charging capacitor 135, and voltage V2 begins to rise. Furthermore, the time derivative (dV2 / dt) of voltage V2 increases after charging starts and then decreases.

[0032] At time tb in Fig. 3A, when capacitor 135 is nearly charged, ECU 160 connects (ON) main contactor (positive electrode side) 143 and disconnects (OFF) precharge contactor 142 (Fig. 2C). That is, Fig. 3A shows an example in which precharge is completed at time tb.

[0033] On the other hand, on the FC system 200 side, since the states of the main contactor (positive side) 143 and the precharge contactor 142 in the BATT & load system 100 are unknown, it is not known whether precharge has been completed. In order to obtain information for estimating the completion of pre-charging, the FCMGECU 240 performs a startup trial at time tc in FIG. 3A when a predetermined first condition is satisfied based on the voltage (corresponding to voltage V2) measured by the voltage sensor 260. The startup trial is performed, for example, by connecting the positive and negative contactors (250) of the contactor unit 250 of the FC system 200. When the contactors (250) of the contactor unit 250 are connected, battery power from the BATT & load system 100 is supplied to the auxiliary equipment 230 via the DC link DL2. This drives an air pump or the like as the auxiliary equipment 230, consuming a certain amount of power in the FC system 200.

[0034] If the time tc is later than the time tb, in other words, if the connection of the contactor (250) of the contactor unit 250 is after the completion of pre-charging, the voltage measured by the voltage sensor 260 will not drop below the predetermined threshold due to the connection of the contactor (250). Based on this phenomenon, the FCMGECU 240 estimates that pre-charging is complete.

[0035] (Example 2) In FIG. 3B, the period up to time ta corresponds to the time when the electric vehicle is stopped (an ignition switch, not shown, is off) (FIG. 2A). When the driver turns on the ignition switch (not shown) of the electric vehicle, ECU 160 connects (turns on) main contactor (negative side) 144 and pre-charge contactor 142 of contactor unit 140 at time ta (FIG. 2B). This starts charging capacitor 135, and voltage V2 begins to rise. Furthermore, the time derivative (dV2 / dt) of voltage V2 increases and then decreases after a certain time has elapsed since the start of charging.

[0036] At time tb in Fig. 3B, the amount of charge in capacitor 135 is insufficient, so ECU 160 maintains the connected (ON) state of main contactor (negative side) 144 and pre-charge contactor 142 of contactor unit 140 (Fig. 2B). In other words, Fig. 3B shows an example in which pre-charging is not completed at time tb.

[0037] On the other hand, on the FC system 200 side, since the states of the main contactor (positive side) 143 and the precharge contactor 142 in the BATT & load system 100 are unknown, it is not known whether precharge has been completed. In order to obtain information for estimating the completion of pre-charging, the FCMGECU 240 performs a start-up trial at time tc in FIG. 3B when a predetermined first condition is satisfied based on the voltage (corresponding to voltage V2) measured by the voltage sensor 260. The start-up trial is the same as in FIG. 3A. When the contactor (250) of the contactor unit 250 is connected, battery power from the BATT & load system 100 is supplied to the auxiliary equipment 230 via the DC link DL2. This drives an air pump or the like as the auxiliary equipment 230, and a certain amount of power is consumed in the FC system 200.

[0038] 2B is maintained at the time tc, in other words, if the contactor (250) of the contactor unit 250 is connected before the pre-charge is completed, the voltage measured by the voltage sensor 260 drops below the predetermined threshold due to the connection of the contactor (250). Strictly speaking, the following occurs: connection of the contactor (250) → power supply to the auxiliary device 230 → a voltage drop occurs at the resistor 141 → the voltage measured by the voltage sensor 260 drops → the voltage measured by the voltage sensor 260 drops below the predetermined threshold. Based on this phenomenon, the FCMGECU 240 does not estimate that the pre-charge is completed.

[0039] At time td, FCMGECU 240 cuts off the positive and negative contactors (250) of contactor unit 250 of FC system 200. Cutting off the contactors (250) of contactor unit 250 stops the supply of battery power to auxiliary equipment 230. This increases the charging current to capacitor 135, and voltage V2 begins to rise. Furthermore, the time derivative (dV2 / dt) of voltage V2 increases after charging resumes and then decreases.

[0040] At time te in Fig. 3B, when capacitor 135 is nearly charged, ECU 160 connects (ON) main contactor (positive side) 143 and disconnects (OFF) precharge contactor 142 (Fig. 2C). That is, Fig. 3B shows an example in which precharge is completed at time te.

[0041] On the other hand, on the FC system 200 side, since the states of the main contactor (positive side) 143 and the precharge contactor 142 in the BATT & load system 100 are unknown, it is not known whether precharge has been completed. To obtain information for estimating the completion of pre-charging, the FCMGECU 240 performs a startup retry at time tf in FIG. 3B when a predetermined second condition is satisfied based on the voltage (corresponding to voltage V2) measured by the voltage sensor 260. Similar to the startup retry, the startup retry connects the positive and negative contactors (250) of the contactor unit 250 of the FC system 200. By connecting the contactors (250) of the contactor unit 250, battery power from the BATT & load system 100 is supplied to the auxiliary equipment 230 via the DC link DL2. This drives an air pump or the like as the auxiliary equipment 230, consuming a certain amount of power in the FC system 200.

[0042] If the time tf is later than the time te, in other words, if the connection of the contactor (250) of the contactor unit 250 is after the completion of pre-charging, the voltage measured by the voltage sensor 260 will not drop below the predetermined threshold due to the connection of the contactor (250). Based on this phenomenon, the FCMGECU 240 estimates that pre-charging is complete.

[0043] When the FCMGECU 240 estimates that pre-charging is complete, it permits the startup of the FC system 200. Using the battery power supplied from the BATT & load system 100, the FCMGECU 240, for example, opens a shutoff valve of a hydrogen tank (not shown) and drives the auxiliary equipment 230 to supply hydrogen and air to the FC stack 210. This starts power generation by the FC stack 210, and the FC system 200 begins operating.

[0044] <Explanation of the flowchart> An example of the startup process executed by the FCMGECU 240 as a startup device will be described with reference to the flowchart of Fig. 4. As an example, the FCMGECU 240 starts the process shown in Fig. 4 when the ignition switch of the electric vehicle is turned on.

[0045] When the voltage measured by voltage sensor 260 (corresponding to voltage V2 of capacitor 135) begins to rise, FCMGECU 240 starts to wait for the voltage to rise in step S10, and then proceeds to step S20.

[0046] In step S20, the FCMGECU 240 determines whether the time derivative (dV2 / dt) of the voltage V2 is equal to or less than a predetermined value α. If the time derivative (dV2 / dt) of the voltage V2 converges to or less than the predetermined value α, the FCMGECU 240 makes an affirmative decision in step S20 and proceeds to step S30. If the time derivative (dV2 / dt) of the voltage V2 does not converge to or less than the predetermined value α, the FCMGECU 240 makes a negative decision in step S20 and returns to step S10. To return to step S10, the FCMGECU 240 waits until the time derivative (dV2 / dt) of the voltage V2 falls to or less than the predetermined value α.

[0047] In step S30, the FCMGECU 240 determines whether t1≧T th1 Determine whether or not t1 is true. t1 is the duration of the state where dV2 / dt≦α is true. T th1 is set to, for example, 100 msec. th1 If the above condition is met, an affirmative decision is made in step S30 and the process proceeds to step S40, whereas if the above condition is not met, a negative decision is made in step S30 and the process returns to step S10. If the process returns to step S10, the above-described processing is repeated.

[0048] In step S40, the FCMGECU 240 waits for a predetermined time (for example, the number of startup attempts × 50 msec) and proceeds to step S50. The number of startup attempts includes startup retries, which will be described later.

[0049] In step S50, the FCMGECU 240 performs a start-up trial, and then the process proceeds to step S60. As described above, the start-up trial involves connecting the positive and negative contactors (250) of the contactor unit 250 of the FC system 200, respectively.

[0050] In step S60, the FCMGECU 240 determines whether V2 is greater than or equal to V2 thIf the condition is met, the FCMGECU 240 makes an affirmative decision in step S60 and proceeds to step S80, and if the condition is not met, the FCMGECU 240 makes a negative decision in step S60 and proceeds to step S70. th is a predetermined determination threshold (for example, the voltage when the SOC of the secondary battery is 10%). t2 is the time elapsed since the start-up attempt (S50).

[0051] In step S70, the FCMGECU 240 determines whether t3≧T th2 At t3, it is determined whether or not the voltage V2 is V2 th is the duration of the state where the temperature is below T th2 is set to, for example, 200 msec. th2 If the above is true, an affirmative decision is made in step S70 and the process returns to step S10, and if the above is not true, a negative decision is made in step S70 and the process proceeds to step S80.

[0052] In step S80, the FCMGECU 240 determines whether t4≧200 msec is true. t4 is the time elapsed since the startup attempt (S50). If the condition is true, the FCMGECU 240 makes an affirmative decision in step S80 and proceeds to step S90. If the condition is not true, the FCMGECU 240 makes a negative decision in step S80 and proceeds to step S70.

[0053] In step S90, the FCMGECU 240 determines whether pre-charging is complete, and ends the processing in Fig. 4. In the embodiment, the FCMGECU 240's estimation of pre-charging completion is referred to as "pre-charging completion determination by the FCMGECU 240."

[0054] According to the embodiment described above, the following advantageous effects are achieved. (1) The starting device (240, 260) according to the embodiment is a starting device for an FC system 200 as a second system, which is started by receiving a power supply from a BATT & load system 100 as a first system including a BATT system 150 as a battery, an inverter 110 as a load that receives a power supply from the BATT system 150, and a precharge circuit 145 provided on a DC link DL1 as a first power line connecting the BATT system 150 and the inverter 110. The BATT & load system 100 and the FC system 200 are connected by a DC link DL2 as a second power line so that the FC system 200 and the inverter 110 are connected in parallel. The start-up device (240, 260) includes a voltage sensor 260 that measures the voltage of the precharge circuit 145 via the DC links DL1 and DL2, and an FCMGECU 240 as a control unit that instructs a start-up attempt of the FC system 200 when a voltage V2 measured by the voltage sensor 260 during execution of precharge by the precharge circuit 145 satisfies a first predetermined condition, and that estimates completion of precharge when the voltage V2 measured by the voltage sensor 260 after the start-up attempt satisfies a second predetermined condition. With this configuration, the FCMGECU 240 can obtain information for estimating the completion of pre-charging in the BATT & load system 100 without requiring communication between the BATT & load system 100 and the FC system 200. That is, the FCMGECU 240 issues a command to perform a startup attempt at time tc (FIG. 3A) when a predetermined first condition is satisfied based on the voltage V2 measured by the voltage sensor 260, causing the FC system 200 to consume a certain amount of power. Then, the completion of pre-charging in the BATT & load system 100 is estimated based on whether a predetermined second condition is satisfied based on the voltage V2 measured by the voltage sensor 260 after the startup attempt. Correctly estimating the completion of pre-charging in the BATT & load system 100 eliminates the concerns of the prior art and leads to the reliable startup of the FC system 200 using battery power after pre-charging is complete. Furthermore, since communication between the BATT & load system 100 as the first system and the FC system 200 as the second system and the interface therefor are no longer necessary, it is possible to reduce costs and improve versatility.

[0055] (2) In the startup device (240, 260) described in (1) above, if the voltage V2 measured by the voltage sensor 260 after the startup attempt does not satisfy the second predetermined condition, the FCMGECU 240 instructs the termination of the startup attempt, and then instructs the startup attempt of the FC system 200 again if the voltage V2 measured by the voltage sensor 260 during precharge execution satisfies the first predetermined condition. This configuration makes it possible to deal appropriately with the case where precharging is not completed at time tc (FIG. 3B) when a startup attempt is instructed. Specifically, it becomes possible to wait until the predetermined first condition is satisfied again based on the voltage V2 measured by the voltage sensor 260 after the startup attempt is completed at time td (FIG. 3B), and then issue another startup attempt instruction for the FC system 200 at time te (FIG. 3B).

[0056] (3) In the startup device (240, 260) described in (1) above, the FCMGECU 240 sets the first predetermined condition to be the elapse of a first predetermined time after the voltage V2 measured by the voltage sensor 260 reaches a predetermined state before the startup attempt, and lengthens the first predetermined time as the number of startup attempts increases. With this configuration, if precharge completion cannot be estimated after a startup attempt is instructed, it is possible to ensure a long time until the next startup attempt.

[0057] (4) In the start-up device (240, 260) described in (2) above, the FCMGECU 240 includes in the predetermined state that the time differential value of the voltage V2 measured by the voltage sensor 260 before the start-up attempt is equal to or less than a first predetermined value. With this configuration, it is possible to accurately grasp the behavior of the voltage V2 during the execution of pre-charging in the BATT & load system 100, and to appropriately estimate the completion of pre-charging in the BATT & load system 100.

[0058] (5) In the start-up device (240, 260) described in (1) above, the FCMGECU 240 determines that the second predetermined condition is that the voltage V2 measured by the voltage sensor 260 after the start-up attempt is equal to or greater than a second predetermined value and that a second predetermined time has elapsed since the start-up attempt. With this configuration, it is possible to accurately grasp the behavior of the voltage V2 after issuing a command to perform a startup attempt, and to appropriately estimate the completion of pre-charging in the BATT & load system 100.

[0059] (6) In the start-up device (240, 260) described in (1) above, the FCMGECU 240 permits the start-up of the FC system 200 when it estimates that the pre-charge is completed. With this configuration, it becomes possible to properly start up the second system using the battery power after precharging is completed in the BATT & load system 100.

[0060] (7) In the start-up device (240, 260) described in (2) above, the FC system 200 receives power supply from the BATT & load system 100 to start up, and upon startup, starts generating power and supplies the FC power to the BATT & load system 100. This configuration makes it possible to properly start up the FC system 200 as the second system.

[0061] The above embodiment can be modified in various ways, and modifications will be described below. (Variation 1) In the embodiment, an example in which the first system is applied to a vehicle has been described, but the first system is not limited to vehicles such as commercial vehicles and construction machinery, and may be mounted on aircraft, ships, etc. Furthermore, the first system is not limited to mobile objects such as the above-mentioned vehicles, and may be applied to stationary power sources provided in homes, factories, public facilities, etc.

[0062] (Variation 2) In the above-described embodiment, a configuration in which a communication interface is not provided between the first system (e.g., BATT & load system 100) and the second system (e.g., FC system 200) constituting the overall system 1 has been exemplified. However, the present invention can also be applied if the first system and the second system are provided with a communication interface to enable communication between the first system and the second system, or if an external control device or the like is configured to provide information about the first system (e.g., information notifying completion of pre-charging) to the second system. Specifically, even in a situation in which the communication interface between the first system and the second system fails or information about the first system cannot be provided to the second system due to a failure of the external control device or the like, the second system can be properly started using the battery power remaining after pre-charging on the first system side is completed.

[0063] (Variation 3) The standby time, duration, elapsed time, etc. exemplified in the embodiment are merely examples and may be changed as appropriate. th1 and T th2 This may also be changed as appropriate.

[0064] The above description is merely an example, and the present invention is not limited to the above-described embodiment and modifications as long as the features of the present invention are not impaired. One or more of the above-described embodiment and modifications can be arbitrarily combined, and modifications can also be combined with each other. [Explanation of symbols]

[0065] 1 Overall system, 100 BATT & load system, 110 Inverter, 120 Motor, 140, 250 Contactor unit, 142 Precharge contactor, 143, 144 Main contactor, 145 Precharge circuit, 150 BATT system, 160 ECU, 200 FC system, 210 FC stack, 220 Converter, 230 Auxiliary equipment, 240 FCMGECU, 260 Voltage sensor

Claims

1. A startup device for a second system, which is different from a first system and starts up by receiving power supply from the first system, the second system including a battery, a load that receives power supply from the battery, and a precharge circuit provided on a first power line connecting the battery and the load, the first system and the second system are connected by a second power line such that the second system and the load are connected in parallel; The starting device is a sensor that measures a voltage of the precharge circuit of the first system via the first power line and the second power line; a control unit that instructs a startup attempt of the second system when a voltage measured by the sensor during execution of precharging by the precharge circuit satisfies a first predetermined condition, and that infers completion of the precharging when a voltage measured by the sensor after the startup attempt satisfies a second predetermined condition; A starting device comprising:

2. 2. The starting device according to claim 1, The control unit instructing an end of the startup attempt when the voltage measured by the sensor after the startup attempt does not satisfy the second predetermined condition, and then instructing another startup attempt of the second system when the voltage measured by the sensor during execution of the precharge satisfies the first predetermined condition. A starting device characterized by:

3. 3. The starting device according to claim 2, The control unit the first predetermined condition is that a first predetermined time has elapsed since the voltage measured by the sensor before the start-up attempt reached a predetermined state; The more the number of times the startup attempt is instructed, the longer the first predetermined time period is set. A starting device characterized by:

4. 4. The starting device according to claim 3, the control unit includes, in the predetermined state, a state in which a time differential value of the voltage measured by the sensor before the start-up attempt is equal to or less than a first predetermined value; A starting device characterized by:

5. 3. The starting device according to claim 1, The control unit the second predetermined condition is that the voltage measured by the sensor after the start-up attempt is equal to or greater than a second predetermined value and that a second predetermined time has elapsed since the start-up attempt. A starting device characterized by:

6. 2. The starting device according to claim 1, When the control unit estimates that the precharge is completed, the control unit permits the start-up of the second system. A starting device characterized by:

7. 2. The starting device according to claim 1, the second system is activated by receiving power supply from the first system, and starts generating power upon activation, and supplies the generated power to the first system. A starting device characterized by:

8. A method for starting a second system, which is different from a first system and receives power supply from a first system including a battery, a load that receives power supply from the battery, and a precharge circuit provided on a first power line connecting the battery and the load, the method comprising: the first system and the second system are connected by a second power line such that the second system and the load are connected in parallel; The startup method includes: acquiring a detection signal from a sensor that measures a voltage of the precharge circuit of the first system via the first power line and the second power line while the precharge circuit is performing precharge; instructing a start-up attempt of the second system when a voltage based on the detection signal acquired from the sensor satisfies a first predetermined condition; inferring completion of the precharge when a voltage based on the detection signal acquired from the sensor after the start-up attempt satisfies a second predetermined condition; A startup method comprising:

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