阅读说明：本技术 燃料电池用泵以及燃料电池用泵的控制方法 (Fuel cell pump and method for controlling fuel cell pump ) 是由 铃木文博 森达志 石川祐一 柿元巧 于 2021-06-02 设计创作，主要内容包括：提供燃料电池用泵以及燃料电池用泵的控制方法。燃料电池用泵具备泵部、马达、控制部、壳体以及温度检测部。控制部执行启动控制和无传感器矢量控制。控制部在启动控制中,在外部气温为设定温度以下的情况下,执行低温启动模式处理。控制部在低温启动模式处理中,执行使向马达供给的启动电流值比执行通常启动模式处理时的该启动电流值大、和将向马达供给的启动电流的供给时间设定为比执行通常启动模式处理时的该供给时间长中的至少一方。(A fuel cell pump and a method for controlling the fuel cell pump are provided. The fuel cell pump includes a pump section, a motor, a control section, a casing, and a temperature detection section. The control section executes start-up control and sensorless vector control. The control unit executes the low-temperature start mode process when the outside air temperature is equal to or lower than the set temperature during the start control. The control unit performs at least one of a process of making a starting current value supplied to the motor larger than the starting current value when the normal starting mode process is performed and a process of setting a supply time of the starting current supplied to the motor to be longer than the supply time when the normal starting mode process is performed in the low-temperature starting mode process.)

1. A pump for a fuel cell is provided with:

a pump section configured to supply a fuel gas or an oxidizing gas to the fuel cell;

a motor configured to drive the pump section;

a control unit configured to control driving of the motor;

a housing including a pump chamber for housing the pump section, a motor chamber for housing the motor, and a control chamber for housing the control section; and

a temperature detection unit configured to detect an outside air temperature,

the control part is used for controlling the operation of the motor,

the starting control is executed until the pump section is started, and the sensorless vector control is executed after the pump section is started,

in the start-up control, the start-up control is executed,

the normal start mode processing is executed when the outside air temperature detected by the temperature detection unit is higher than a preset temperature,

a low-temperature start mode process is executed when the outside air temperature detected by the temperature detection unit is equal to or lower than the set temperature,

the low-temperature start mode processing is configured to execute at least one of a start current value supplied to the motor being larger than the start current value when the normal start mode processing is executed and a supply time of the start current supplied to the motor being set to be longer than the supply time when the normal start mode processing is executed,

the control device is configured to transition from the start control to the sensorless vector control after the pump section is started.

2. The pump for a fuel cell according to claim 1,

the low temperature start mode processing includes:

a step of making a starting current value supplied to the motor larger than the starting current value when the normal starting mode processing is executed; and

the supply time of the starting current to the motor is set to be longer than that when the normal starting mode processing is executed,

the maximum value of the starting current value in the low-temperature starting mode processing is larger than the maximum value of the starting current value in the normal starting mode processing.

3. The pump for a fuel cell according to claim 1 or 2,

the low-temperature start mode process is executed a plurality of times.

4. The pump for a fuel cell according to claim 3,

the control unit is configured to set the supply time of the starting current to be longer as the number of times of execution of the low-temperature start mode processing increases.

5. The pump for a fuel cell according to claim 3,

the control unit is configured to set a supply time of the starting current to be shorter as the number of times of execution of the low-temperature start mode process increases, and the set supply time of the starting current is longer than the supply time of the starting current when the normal start mode process is executed.

6. The pump for a fuel cell according to any one of claims 1 to 5,

the control unit is configured to gradually shorten a cycle of the start current when the low-temperature start mode process is executed.

7. The pump for a fuel cell according to any one of claims 1 to 5,

the control unit is configured to gradually increase a cycle of the start-up current when the low-temperature start-up mode process is executed.

8. A method for controlling a pump for a fuel cell, the pump for a fuel cell comprising:

a pump section configured to supply a fuel gas or an oxidizing gas to the fuel cell;

a motor configured to drive the pump section; and

a control unit configured to control driving of the motor,

the control method of the pump for the fuel cell includes:

start control is performed until the pump section is started; and

a sensorless vector control to which the start control is shifted after the pump section is started,

the start control includes:

comparing the outside air temperature detected by a temperature detection unit that detects the outside air temperature with a preset temperature;

executing a normal start mode process when the outside air temperature detected by the temperature detection unit is higher than a preset temperature as a result of the comparison; and

executing a low temperature start mode process when the outside air temperature detected by the temperature detection unit is equal to or lower than the set temperature,

the low temperature start mode processing includes: the method further includes the steps of performing at least one of making a starting current value supplied to the motor larger than the starting current value at the time of performing the normal starting mode processing and setting a supply time of the starting current supplied to the motor to be longer than the supply time at the time of performing the normal starting mode processing.

9. The control method of a pump for a fuel cell according to claim 8,

the low temperature start mode processing includes:

a step of making a starting current value supplied to the motor larger than the starting current value when the normal starting mode processing is executed; and

the supply time of the starting current to the motor is set to be longer than that when the normal starting mode processing is executed,

a maximum value of the starting current value in the low-temperature starting mode processing is larger than a maximum value of the starting current value in the normal starting mode processing,

the low-temperature start mode process is executed a plurality of times.

Technical Field

The present disclosure relates to a pump for a fuel cell and a control method of the pump for the fuel cell.

Background

In recent years, vehicles equipped with fuel cell systems have been put to practical use. A fuel cell system includes a fuel cell that generates electric power by chemically reacting hydrogen as a fuel gas with oxygen contained in air as an oxidant gas. The fuel cell pump is used, for example, as a pump for supplying hydrogen to the fuel cell. As a fuel cell pump, for example, a Roots pump (Roots pump) is known as disclosed in japanese patent application laid-open No. 2006-283664. The roots pump includes a casing, a pump section for supplying hydrogen to the fuel cell, a pump chamber formed in the casing and accommodating the pump section, and a motor for driving the pump section. The roots pump is further provided with a control unit that controls driving of the motor. When the pump unit is started, the control unit supplies a preset starting current to the motor to control the driving of the motor.

In the fuel cell pump, hydrogen (hydrogen off-gas) that has not reacted with oxygen in the fuel cell is drawn into the pump chamber. When hydrogen is drawn into the pump chamber, water produced by the fuel cell in accordance with power generation is also drawn into the pump chamber. Therefore, for example, when the operation of the pump unit is stopped in a low-temperature environment, water present in the pump chamber freezes to become ice. Here, in the pump chamber, when water present between the pump section and an inner surface of the casing partitioning the pump chamber freezes and turns into ice, the pump section may be adhered and fixed to the casing via the ice.

Disclosure of Invention

The purpose of the present disclosure is: provided are a fuel cell pump and a control method for the fuel cell pump.

The fuel cell pump according to claim 1 for achieving the above object includes: a pump section configured to supply a fuel gas or an oxidizing gas to the fuel cell; a motor configured to drive the pump section; a control unit configured to control driving of the motor; a housing including a pump chamber that houses the pump section, a motor chamber that houses the motor, and a control chamber that houses the control section; and a temperature detection unit configured to detect an outside air temperature. The control unit is configured to execute start control until the pump unit is started and sensorless vector control performed after the pump unit is started. The control unit is configured to execute a normal start mode process when the outside air temperature detected by the temperature detection unit is higher than a preset temperature during the start control, and configured to execute a low temperature start mode process when the outside air temperature detected by the temperature detection unit is equal to or lower than the preset temperature. The control unit is configured to execute, in the low-temperature start mode processing, at least one of a start current value supplied to the motor being larger than the start current value when the normal start mode processing is executed and a supply time of the start current supplied to the motor being longer than the supply time when the normal start mode processing is executed. The control unit is configured to shift from the start control to the sensorless vector control after the pump unit is started.

In claim 2 for achieving the above object, a method for controlling a pump for a fuel cell is provided. The fuel cell pump includes: a pump section configured to supply a fuel gas or an oxidizing gas to the fuel cell; a motor configured to drive the pump section; and a control unit configured to control driving of the motor. The control method of the pump for the fuel cell includes: start control is performed until the pump section is started; and sensorless vector control that is shifted from the start control to the sensorless vector control after the pump section is started. The start control includes: comparing the outside air temperature detected by a temperature detection unit that detects the outside air temperature with a preset temperature; executing a normal start mode process when the outside air temperature detected by the temperature detection unit is higher than a preset temperature as a result of the comparison; and executing a low-temperature start mode process when the outside air temperature detected by the temperature detection unit is equal to or lower than the set temperature, the low-temperature start mode process including: the method further includes the steps of performing at least one of making a starting current value supplied to the motor larger than the starting current value at the time of performing the normal starting mode processing and setting a supply time of the starting current supplied to the motor to be longer than the supply time at the time of performing the normal starting mode processing.

Drawings

Fig. 1 is a plan sectional view showing a fuel cell pump according to an embodiment.

Fig. 2 is a cross-sectional view taken along line 2-2 of fig. 1.

Fig. 3 is a graph showing a relationship between current and time when the pump unit is activated by executing the cold start mode processing.

Fig. 4 is a flowchart for explaining control of the inverter device.

Detailed Description

Hereinafter, an embodiment embodying the fuel cell pump and a method of controlling the fuel cell pump will be described with reference to fig. 1 to 4. The fuel cell pump of the present embodiment is used as a pump for supplying hydrogen to a fuel cell that generates electric power by chemically reacting hydrogen as a fuel gas with oxygen contained in air as an oxidant gas.

As shown in fig. 1, a casing 11 of the fuel cell pump 10 is a tubular shape having a motor casing 12, a gear casing 13, a rotor casing 14, and a lid member 15. The motor case 12 has a plate-like bottom wall 12a and a bottom-closed cylindrical shape having a peripheral wall 12b extending cylindrically from the outer peripheral portion of the bottom wall 12 a. The gear housing 13 has a plate-like bottom wall 13a and a peripheral wall 13b extending cylindrically from the outer peripheral portion of the bottom wall 13 a. The gear housing 13 is coupled to an opening-side end of the peripheral wall 12b of the motor housing 12. The bottom wall 13a of the gear housing 13 closes the opening of the peripheral wall 12b of the motor housing 12.

The rotor case 14 has a plate-like bottom wall 14a and a bottom-closed cylindrical shape having a cylindrical peripheral wall 14b extending from the outer peripheral portion of the bottom wall 14 a. The rotor housing 14 is coupled to an opening-side end of the peripheral wall 13b of the gear housing 13. The bottom wall 14a of the rotor case 14 closes the opening of the peripheral wall 13b of the gear case 13. The cover member 15 is plate-shaped. The cover member 15 is coupled to an end of the rotor case 14 on the opening side of the peripheral wall 14b, faces the bottom wall 14a, and closes the peripheral wall 14 b. The axial direction of the peripheral wall 12b of the motor housing 12, the axial direction of the peripheral wall 13b of the gear housing 13, and the axial direction of the peripheral wall 14b of the rotor housing 14 are aligned with each other.

The fuel cell pump 10 includes a drive shaft 16 and a driven shaft 17 rotatably supported in a state of being arranged in parallel to each other in a casing 11. The rotational axis direction of the drive shaft 16 and the driven shaft 17 coincides with the axial center direction of the peripheral walls 12b, 13b, and 14 b. A disk-shaped drive gear 18 is fixed to the drive shaft 16. A disk-shaped driven gear 19 that meshes with the drive gear 18 is fixed to the driven shaft 17. A drive rotor 20 is provided on the drive shaft 16. The driven shaft 17 is provided with a driven rotor 21 that meshes with the driving rotor 20.

The fuel cell pump 10 includes a motor 22 that drives the driving rotor 20 and the driven rotor 21 by rotating the driving shaft 16. The motor 22 is accommodated in a motor chamber 23 formed in the housing 11. The motor chamber 23 is defined by the bottom wall 12a of the motor housing 12, the peripheral wall 12b of the motor housing 12, and the bottom wall 13a of the gear housing 13. The motor 22 has: a cylindrical motor rotor 22a attached to and stopped by the drive shaft 16 so as to be rotatable integrally with the drive shaft 16; and a cylindrical stator 22b fixed to an inner peripheral surface of the peripheral wall 12b of the motor housing 12 and surrounding the motor rotor 22 a. The stator 22b has coils 22c wound around teeth not shown. The motor 22 is driven by supplying electric power to the coil 22c, and the motor rotor 22a rotates integrally with the drive shaft 16.

A gear chamber 24 accommodating the drive gear 18 and the driven gear 19 is formed in the housing 11. The gear chamber 24 is defined by the bottom wall 13a of the gear housing 13, the peripheral wall 13b of the gear housing 13, and the bottom wall 14a of the rotor housing 14. The drive gear 18 and the driven gear 19 are accommodated in the gear chamber 24 in a mutually meshed state. Oil (oil) is sealed in the gear chamber 24. The oil contributes to lubrication of the drive gear 18 and the driven gear 19 and suppresses temperature rise. The drive gear 18 and the driven gear 19 can be rotated at high speed without burning and abrasion by being immersed in oil and rotated.

A rotor chamber 25 as a pump chamber for accommodating the driving rotor 20 and the driven rotor 21 is formed in the housing 11. The rotor chamber 25 is defined by the bottom wall 14a of the rotor case 14, the peripheral wall 14b of the rotor case 14, and the cover member 15. The driving rotor 20 and the driven rotor 21 are accommodated in the rotor chamber 25 in a mutually meshed state.

The fuel cell pump 10 includes an inverter device 60 as a control unit that controls driving of the motor 22. A bottomed cylindrical cover 61 is attached to the bottom wall 12a of the motor case 12. An inverter chamber 62 as a control chamber for housing the inverter device 60 is defined by the bottom wall 12a of the motor case 12 and the cover 61. In the present embodiment, the rotor chamber 25, the gear chamber 24, the motor chamber 23, and the inverter chamber 62 are arranged in this order in the rotational axis direction of the drive shaft 16.

The bottom wall 13a of the gear housing 13 partitions the gear chamber 24 from the motor chamber 23 in the rotational axis direction of the drive shaft 16. The bottom wall 14a of the rotor housing 14 partitions the gear chamber 24 from the rotor chamber 25 in the rotational axis direction of the drive shaft 16. The drive shaft 16 penetrates the bottom wall 13a of the gear housing 13 and the bottom wall 14a of the rotor housing 14. The driven shaft 17 penetrates the bottom wall 14a of the rotor case 14.

A 1 st bearing accommodating recess 27 in a circular hole shape is formed in the inner bottom surface 13e of the bottom wall 13a of the gear housing 13, and the 1 st bearing accommodating recess 27 accommodates a 1 st bearing 26 rotatably supporting the drive shaft 16. The drive shaft 16 passes through the 1 st bearing accommodating recess 27. A 1 st seal accommodating recess 29 having a circular hole shape is formed in the bottom surface 27a of the 1 st bearing accommodating recess 27, and the 1 st seal accommodating recess 29 is penetrated by the drive shaft 16 and accommodates an annular 1 st seal member 28 that seals between the gear chamber 24 and the motor chamber 23. The 1 st seal accommodating recess 29 communicates with the 1 st bearing accommodating recess 27. Further, an annular 1 st spacer 30 is disposed between the 1 st bearing 26 and the bottom surface 27a of the 1 st bearing accommodating recess 27 in the rotation axis direction of the drive shaft 16.

A 2 nd bearing accommodating recess 32 and a 3 rd bearing accommodating recess 37 each having a circular hole shape are formed in an outer surface 14e of the bottom wall 14a of the rotor case 14, and the 2 nd bearing accommodating recess 32 and the 3 rd bearing accommodating recess 37 accommodate a 2 nd bearing 31 and a 3 rd bearing 36 rotatably supporting the drive shaft 16 and the driven shaft 17, respectively. The drive shaft 16 passes through the 2 nd bearing accommodating recess 32. The driven shaft 17 passes through the 3 rd bearing accommodating recess 37.

A circular hole-shaped 2 nd seal accommodating recess 34 is formed in a bottom surface 32a of the 2 nd bearing accommodating recess 32, and the 2 nd seal accommodating recess 34 is penetrated by the drive shaft 16 and accommodates an annular 2 nd seal member 33 that seals between the gear chamber 24 and the rotor chamber 25. The 2 nd seal accommodating recess 34 communicates with the 2 nd bearing accommodating recess 32. Further, an annular 2 nd spacer 35 is disposed between the 2 nd bearing 31 and the bottom surface 32a of the 2 nd bearing accommodating recess 32 in the rotation axis direction of the drive shaft 16.

A circular hole-shaped 3 rd seal accommodating recess 39 is formed in a bottom surface 37a of the 3 rd bearing accommodating recess 37, and the annular 3 rd seal member 38 that seals between the gear chamber 24 and the rotor chamber 25 is accommodated in the 3 rd seal accommodating recess 39, while the driven shaft 17 penetrates through the 3 rd seal accommodating recess 39. The 3 rd seal accommodating recess 39 communicates with the 3 rd bearing accommodating recess 37. Further, an annular 3 rd spacer 40 is disposed between the 3 rd bearing 36 and the bottom surface 37a of the 3 rd bearing accommodating recess 37 in the rotation axis direction of the driven shaft 17.

A 4 th bearing accommodating recess 42 in a circular hole shape is formed in the inner bottom surface 13e of the bottom wall 13a of the gear housing 13, and the 4 th bearing accommodating recess 42 accommodates a 4 th bearing 41 that rotatably supports the 1 st end portion, which is one end portion of the driven shaft 17. The opening edge of the 4 th bearing accommodating recess 42 is continuous with the inner bottom surface 13e of the bottom wall 13a of the gear housing 13. The 1 st end of the driven shaft 17 is disposed in the 4 th bearing accommodating recess 42 and is rotatably supported by the 4 th bearing 41. The other end portion, i.e., the 2 nd end portion, of the driven shaft 17 passes through the 3 rd bearing accommodating recess portion 37 and the 3 rd seal accommodating recess portion 39 and protrudes into the rotor chamber 25. A driven rotor 21 is attached to the 2 nd end of the driven shaft 17, and the 2 nd end of the driven shaft 17 is a free end. The driven shaft 17 is thereby supported by the housing 11 in a single arm (cantilever).

A cylindrical bearing portion 44 is formed on an inner bottom surface 12e of the bottom wall 12a of the motor housing 12, and the bearing portion 44 accommodates a 5 th bearing 43 that rotatably supports a 1 st end portion, which is one end portion of the drive shaft 16. The 1 st end portion of the drive shaft 16 is disposed inside the bearing portion 44 and is rotatably supported by the 5 th bearing 43. The other end portion, i.e., the 2 nd end portion, of the drive shaft 16 passes through the 1 st seal accommodating recess 29, the 1 st bearing accommodating recess 27, the gear chamber 24, the 2 nd bearing accommodating recess 32, and the 2 nd seal accommodating recess 34 and protrudes into the rotor chamber 25. A drive rotor 20 is mounted to the 2 nd end of the drive shaft 16, with the 2 nd end of the drive shaft 16 being a free end. Thereby, the drive shaft 16 is supported by the housing 11.

As shown in fig. 2, the drive rotor 20 and the driven rotor 21 are formed in a figure-8 shape (hourglass shape) in a cross section perpendicular to the rotational axis direction of the drive shaft 16 and the driven shaft 17. The driving rotor 20 has two mountain teeth (convex teeth) 20a and valley teeth (concave teeth) 20b formed between the mountain teeth 20 a. The driven rotor 21 has two mountain teeth 21a and valley teeth 21b formed between the mountain teeth 21 a.

The driving rotor 20 and the driven rotor 21 can rotate in the rotor chamber 25 while repeating the meshing of the mountain teeth 20a of the driving rotor 20 and the valley teeth 21b of the driven rotor 21 and the meshing of the valley teeth 20b of the driving rotor 20 and the mountain teeth 21a of the driven rotor 21. The driving rotor 20 rotates in the direction of an arrow R1 shown in fig. 2, and the driven rotor 21 rotates in the direction of an arrow R2 shown in fig. 2.

A suction port 45 is formed in the lower portion of the peripheral wall 14b of the rotor case 14 in the direction Z1 of gravity. Further, the discharge port 46 is formed in the upper portion of the peripheral wall 14b of the rotor case 14 in the gravity direction Z1. The suction port 45 is connected to a hydrogen discharge port 50b of the fuel cell 50 via a 1 st connection pipe 50 a. The discharge port 46 is connected to a hydrogen supply port 50d of the fuel cell 50 via a 2 nd connection pipe 50 c.

As shown in fig. 1 and 2, when the drive shaft 16 is rotated by the driving of the motor 22, the driven shaft 17 is rotated in the reverse direction with respect to the drive shaft 16 through the gear coupling of the drive gear 18 and the driven gear 19 that mesh with each other. Accordingly, the driving rotor 20 and the driven rotor 21 are rotated in opposite directions in a state of meshing with each other, and when the driving rotor 20 and the driven rotor 21 are rotated in the fuel cell pump 10, hydrogen (hydrogen off-gas) that has not reacted with oxygen in the fuel cell 50 is sucked into the rotor chamber 25 through the hydrogen discharge port 50b, the 1 st connecting pipe 50a, and the suction port 45. The hydrogen sucked into the rotor chamber 25 is discharged from the discharge port 46 by the rotation of the driving rotor 20 and the driven rotor 21, and is supplied to the fuel cell 50 through the 2 nd connecting pipe 50c and the hydrogen supply port 50 d. Therefore, the driving rotor 20 and the driven rotor 21 constitute a pump section P for supplying hydrogen to the fuel cell 50. The fuel cell pump 10 of the present embodiment is a roots pump in which a pump portion P is formed by a driving rotor 20 and a driven rotor 21.

As shown in fig. 1, the fuel cell pump 10 includes a temperature sensor 63 as a temperature detector for detecting an outside air temperature T1, and a pressure sensor 64 for detecting a discharge pressure of the fuel cell pump 10. The pressure sensor 64 detects the pressure of the hydrogen discharged from the rotor chamber 25 to the 2 nd connecting pipe 50c through the discharge port 46 by the rotation of the driving rotor 20 and the driven rotor 21. The temperature sensor 63 and the pressure sensor 64 are electrically connected to the inverter device 60.

The inverter device 60 stores a determination program for determining that the pump section P is activated when the discharge pressure detection signal is received from the pressure sensor 64, and determining that the pump section P is deactivated when the discharge pressure detection signal is not received from the pressure sensor 64. Here, "a state in which the pump section P is stopped" means "a state in which the driving rotor 20 and the driven rotor 21 do not rotate", and "a state in which the pump section P starts to be started" means "a state in which the driving rotor 20 and the driven rotor 21 start to rotate". The inverter device 60 is configured to execute start control until the pump section P is started and sensorless vector control after the pump section P is started.

The inverter device 60 receives a signal relating to the outside air temperature T1 detected by the temperature sensor 63. The inverter device 60 stores in advance a temperature comparison program for comparing the outside air temperature T1 detected by the temperature sensor 63 with a preset temperature T2 based on a signal received from the temperature sensor 63. The inverter device 60 stores in advance a program for executing the normal start mode process when the outside air temperature T1 detected by the temperature sensor 63 is higher than a preset set temperature T2, and executing the low temperature start mode process when the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2.

Here, when the outside air temperature T1 detected by the temperature sensor 63 is higher than the set temperature T2, it is estimated that water will not freeze in the rotor chamber 25 even if water is present in the rotor chamber 25. When the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2, it is estimated that water freezes in the rotor chamber 25 when water is present in the rotor chamber 25. Such estimation is grasped in advance by an experiment, for example. Therefore, the "set temperature T2" is a temperature that is determined in advance by, for example, an experiment in order to determine whether water is frozen in the rotor chamber 25 when water is present in the rotor chamber 25.

The inverter device 60 stores, in advance, a program for supplying to the motor 22 when the normal start mode process is executed: a starting current of a minimum starting current value required for a minimum time required for starting the pump section P. The cycle of the starting current when the normal starting mode processing is executed is always set to be constant.

When the low-temperature start mode process is executed, the inverter device 60 stores a program for increasing the start current value supplied to the motor 22 to be larger than the start current value when the normal start mode process is executed and for setting the supply time of the start current to be supplied to the motor 22 to be longer than the supply time when the normal start mode process is executed. The inverter device 60 executes this program in order to execute the start-up control of the pump section P. Specifically, when the low-temperature start mode process is executed, the inverter device 60 supplies the motor 22 with a start current value that is approximately 2 times the start current value supplied to the motor 22 when the normal start mode process is executed, for example. Further, when the low-temperature start mode process is executed, the inverter device 60 sets the supply time of the start current to the motor 22 to be about 10 times as long as the supply time of the start current to the motor 22 when the normal start mode process is executed, for example.

As shown in fig. 3, the inverter device 60 stores a program for executing the low-temperature start mode processing a plurality of times in advance. When the discharge pressure detection signal is not received from the pressure sensor 64 even when the 1 st-time low-temperature start mode process is executed, for example, the inverter device 60 determines that the pump section P is stopped, that is, the pump section P is not yet started, and executes the low-temperature start mode process again.

The inverter device 60 stores a program for gradually shortening the cycle of the starting current when the low-temperature start mode process is executed. The cycle of the starting current when the low-temperature starting mode processing is executed is set to be always gradually shortened.

The inverter device 60 is stored with a program for executing a vector control mode process of performing sensorless vector control of the motor 22 when it is determined that the pump section P starts to be activated upon receiving a detection signal of the discharge pressure from the pressure sensor 64. The inverter device 60 executes this routine for sensorless vector control of the motor 22.

Further, the inverter device 60 stores in advance a program that executes an abnormality determination process for determining that some kind of abnormality has occurred when the discharge pressure detection signal is not received from the pressure sensor 64 after the normal start mode process is executed.

Next, a method of controlling the fuel cell pump 10 according to the present embodiment will be described, and an operation of the present embodiment will be described. The inverter device 60 performs: start control is performed until the pump section P is started; and sensorless vector control to which transition is made after the pump section P is started.

As shown in fig. 4, when the inverter device 60 is to start the pump section P, first, in step S11, it receives a signal relating to the outside air temperature T1 detected by the temperature sensor 63. Then, in step S12, the inverter device 60 performs a temperature comparison step of comparing the outside air temperature T1 detected by the temperature sensor 63 with a preset temperature T2 based on the signal received from the temperature sensor 63.

If the comparison result of the temperature comparison step performed in step S12 is that the outside air temperature T1 detected by the temperature sensor 63 is higher than the set temperature, the inverter device 60 proceeds to step S13, and performs a process execution step of executing the normal start mode process in step S13. Thereby, the inverter device 60 supplies to the motor 22: a starting current of a minimum starting current value required for a minimum time required for starting the pump section P. The period of the starting current at this time is always constant. Then, the inverter device 60 determines in step S14 whether or not a detection signal of the discharge pressure is received from the pressure sensor 64. When it is determined in step S14 that the discharge pressure detection signal is received from the pressure sensor 64, the inverter device 60 transitions to the normal control in step S15. The inverter device 60 determines that the pump section P has started to be started, and executes a vector control mode process of performing sensorless vector control on the motor 22 in step S15. On the other hand, when it is determined in step S14 that the discharge pressure detection signal has not been received from the pressure sensor 64, the inverter device 60 shifts the process to step S16, determines that some abnormality has been detected, and performs an abnormality determination process.

In the fuel cell pump 10, hydrogen (hydrogen off-gas) that has not reacted with oxygen in the fuel cell 50 is sucked into the rotor chamber 25. At this time, water produced by the power generation of the fuel cell 50 is also sucked into the rotor chamber 25. Therefore, for example, when the operation of the pump section P is stopped in a low-temperature environment, water present in the rotor chamber 25 freezes to become ice. Here, in the rotor chamber 25, when water present between the driving rotor 20 and the driven rotor 21 and the inner surface of the motor housing 12 partitioning the rotor chamber 25 freezes to become ice, the driving rotor 20 and the driven rotor 21 may be adhered and fixed to the rotor housing 14 via the ice.

If the comparison result of the temperature comparison step performed in step S12 is that the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2, the inverter device 60 transitions the process to step S17. The inverter device 60 performs a process execution step of executing the low temperature start mode process in step S17. Accordingly, the value of the starting current to be supplied to the motor 22 becomes larger than when the normal starting mode processing is executed, and the supply time of the starting current to the motor 22 becomes longer than when the normal starting mode processing is executed. That is, the maximum value of the start-up current value in the low-temperature start-up mode processing is larger than the maximum value of the start-up current value in the normal start-up mode processing.

The cycle of the starting current at this time is different from the cycle of the starting current at the time of executing the normal starting mode processing, and the inverter device 60 gradually shortens the cycle of the starting current. For example, the lower the outside air temperature T1 detected by the temperature sensor 63 is relative to the set temperature T2, the higher the possibility that the driving rotor 20 and the driven rotor 21 are firmly adhered and fixed to the rotor case 14 via ice. In such a case, the driving rotor 20 and the driven rotor 21 are more easily peeled from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14 when the rotation is started at a slow rotation speed than when the motor 22 is started at a fast rotation speed.

In addition, when the 1 st low temperature start mode process is executed in step S17, the inverter device 60 shifts the process to step S18, and determines whether a detection signal of the discharge pressure is received from the pressure sensor 64 in step S18. When it is determined in step S18 that the discharge pressure detection signal has not been received from the pressure sensor 64, the inverter device 60 transitions the process to step S17 and executes the 2 nd-time low-temperature start mode process. In this way, when the inverter device 60 does not receive the detection signal of the discharge pressure from the pressure sensor 64 even when the 1 st low temperature start mode process is executed, it is determined that the pump portion P is stopped, that is, the pump portion P is not yet started, and the low temperature start mode process is executed again.

When the 2 nd low-temperature start mode processing is executed by the inverter device 60, the impact force generated by switching the rotational direction of the motor 22 is transmitted to the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the motor housing 12 that partitions the rotor chamber 25. This allows the driving rotor 20 and the driven rotor 21 to be separated from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the motor housing 12, and the driving rotor 20 and the driven rotor 21 start to rotate. When it is determined in step S18 that the discharge pressure detection signal has been received from the pressure sensor 64, the inverter device 60 shifts the process to the normal control in step S15. The inverter device 60 determines that the pump section P has started to be started, and executes a vector control mode process of performing sensorless vector control on the motor 22 in step S15.

In the present embodiment, the pump section P is activated by executing the cold start mode processing twice, but when the pump section P is not activated even if the cold start mode processing is executed twice, the inverter device 60 repeats the processing of step S17 and thereafter.

Therefore, the start control includes step S11, step S12, step S13, step S14, step S17, and step S18. In addition, the sensorless vector control includes step S15.

For the purpose of facilitating understanding of the effects of the present embodiment, a conventional pump for a fuel cell described in the background art is mentioned.

As described in the background art, the pump section is adhered and fixed to the casing through ice in a low-temperature environment. Here, when the pump section is activated, consider the following: the control section always supplies a preset value of starting current to the motor regardless of whether the pump section is fixed to the casing through ice adhesion. In this case, for example, when the pump section is attached and fixed to the casing via ice, the time required for starting the pump section becomes longer than in the case where the pump section is not attached and fixed to the casing via ice, and responsiveness is poor.

In the following, consider the following: when the pump section is started, the control section always supplies the motor with a starting current of such a value that the pump section can be immediately driven even when the pump section is fixed to the casing via ice adhesion. In this case, for example, the following cases are assumed: the control unit supplies the motor with a starting current of such a value that the pump unit can be driven when the pump unit is fixed to the casing via ice adhesion, even when the pump unit is not fixed to the casing via ice adhesion. Therefore, an unnecessarily large value of starting current is supplied to the motor, and thus power is wastefully consumed.

In the above embodiment, the following effects can be obtained.

(1) When the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2, the inverter device 60 executes the low temperature start mode process. Therefore, for example, when the pump section P is started, even if the driving rotor 20 and the driven rotor 21 are adhered and fixed to the rotor case 14 via ice, both the starting current value supplied to the motor 22 is made larger than the starting current value when the normal start mode processing is executed and the supply time of the starting current supplied to the motor 22 is set longer than the supply time when the normal start mode processing is executed. Accordingly, for example, when starting the pump section P, the inverter device 60 does not execute the normal start mode process even though the driving rotor 20 and the driven rotor 21 are fixed to the rotor case 14 via ice adhesion, and therefore, the time required for starting the pump section can be shortened.

On the other hand, when the outside air temperature T1 detected by the temperature sensor 63 is higher than the preset temperature T2, the inverter device 60 executes the normal activation mode process. Therefore, for example, when the pump section P is started, the following does not occur: although the driving rotor 20 and the driven rotor 21 are not fixed to the rotor case 14 via ice adhesion, at least one of the starting current value supplied to the motor 22 is set to be larger than the starting current value when the normal starting mode process is performed and the supply time of the starting current supplied to the motor 22 is set to be longer than the supply time when the normal starting mode process is performed, as in the low-temperature starting mode process. As a result, it is possible to avoid unnecessarily increasing the value of the starting current to be supplied to the motor 22 and unnecessarily increasing the supply time of the starting current to the motor 22, and thus wasteful power consumption can be suppressed. As described above, the time required to start the pump section P can be shortened, and wasteful power consumption can be suppressed.

(2) For example, the pump section P can be started more easily than in the case where only one of increasing the starting current value to be supplied to the motor 22 and setting the supply time of the starting current to be supplied to the motor 22 to be longer than the supply time when the normal start mode processing is executed.

(3) For example, when the pump section P is not activated even if the inverter device 60 executes the 1 st cold start mode process, the inverter device 60 executes the cold start mode process again. Then, the impact force generated by switching the rotational direction of the motor 22 is transmitted to the ice present between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14 that partitions the rotor chamber 25. This makes it possible to easily peel the driving rotor 20 and the driven rotor 21 from ice present between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14, and thus the pump section P can be easily started.

(4) For example, the lower the outside air temperature T1 detected by the temperature sensor 63 is relative to the set temperature T2, the higher the possibility that the driving rotor 20 and the driven rotor 21 are firmly adhered and fixed to the rotor case 14 via ice. In such a case, the driving rotor 20 and the driven rotor 21 are more easily peeled from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14 when the rotation is started at a slow rotation speed than when the motor 22 is started at a fast rotation speed. Then, the inverter device 60 gradually shortens the cycle of the starting current when the low temperature starting mode process is executed. Thus, the motor 22 starts rotating at a slower rotation speed than when the cycle of the starting current is always constant. Accordingly, even when the driving rotor 20 and the driven rotor 21 are firmly attached and fixed to the rotor case 14 via ice, the driving rotor 20 and the driven rotor 21 can be peeled off from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14. Therefore, the pump section P can be easily started.

The above embodiment can be modified and implemented as follows. The above-described embodiment and the following modifications can be combined with each other within a range not technically contradictory to the technology.

In an embodiment, the following may be used: in the low-temperature start mode process, inverter device 60 performs only one of a process of making the start current value supplied to motor 22 larger than the start current value during the normal start mode process and a process of setting the supply time of the start current to motor 22 longer than the supply time during the normal start mode process. In short, the inverter device 60 may be configured to perform at least one of the low-temperature start mode processing to increase the start current value supplied to the motor 22 to be larger than the start current value during the normal start mode processing, and the low-temperature start mode processing to set the supply time of the start current supplied to the motor 22 to be longer than the supply time during the normal start mode processing.

In the embodiment, the inverter device 60 may execute the following control: the supply time of the starting current is set to be long as the number of times of execution of the low temperature starting mode process increases. For example, the lower the outside air temperature T1 detected by the temperature sensor 63 is relative to the set temperature T2, the higher the possibility that the driving rotor 20 and the driven rotor 21 are firmly adhered and fixed to the rotor case 14 via ice. In such a case, the pump section P may not be activated when the inverter device 60 executes the cold start mode processing only once. Accordingly, the inverter device 60 may be: the supply time of the starting current is set to be long as the number of times of execution of the low temperature starting mode process increases. Thus, for example, the pump section P can be started at a stage where the number of times of execution of the cold start mode process is small, as compared to a case where the inverter device 60 always keeps the supply time of the starting current constant even if the number of times of execution of the cold start mode process is increased. Therefore, the time required for starting the pump section P can be shortened, and wasteful power consumption can be suppressed.

In addition, for example, compared to the case where the pump section P is started by the 3 rd-time low-temperature start mode process with the supply time of the start current always set to the 3 second period, the time required for the start can be shortened when the pump section P is started by the 3 rd-time low-temperature start mode process with the supply times set to the 1 st-3 rd-time low-temperature start mode process being set to the 1 second period, the 2 second period, and the 3 second period, respectively.

In the embodiment, the inverter device 60 may perform control as follows: as the number of times of execution of the low-temperature start-up mode process increases, the supply time of the start-up current is set to be short so that the set supply time of the start-up current is longer than the supply time of the start-up current when the normal start-up mode process is executed. For example, even if the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2, the outside air temperature T1 detected by the temperature sensor 63 is closer to the set temperature T2, and even if the driving rotor 20 and the driven rotor 21 are adhesively fixed to the rotor case 14 via ice, there is a high possibility that the driving rotor and the driven rotor are not so firmly adhesively fixed. In such a case, if the inverter device 60 executes the cold start mode processing several times, the pump section P is likely to start starting immediately. Accordingly, the inverter device 60 may shorten the supply time of the starting current as the number of times of execution of the low temperature starting mode process increases. Thus, for example, as compared with a case where the inverter device 60 always keeps the supply time of the starting current constant even if the number of times of execution of the low-temperature start mode process is increased, it is possible to reduce as much as possible the time during which the inverter device 60 unnecessarily supplies the starting current to the motor 22 after the driving rotor 20 and the driven rotor 21 are peeled from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14. Therefore, wasteful power consumption can be suppressed.

In addition, for example, compared to the case where the supply time of the starting current is always set to 3 seconds and the pump section P is started by the 3 rd start control, the supply time in the 1 st to 3 rd start controls is set to 3 seconds, 2 seconds, and 1 second, respectively, and the time required for the start can be shortened when the pump section P is started by the 3 rd start control.

In the embodiment, the following setting is also possible: the period of the start-up current when the low-temperature start-up mode process is executed is gradually increased. For example, even if the outside air temperature T1 detected by the temperature sensor 63 is equal to or lower than the set temperature T2, the outside air temperature T1 detected by the temperature sensor 63 is closer to the set temperature T2, and even if the driving rotor 20 and the driven rotor 21 are adhesively fixed to the rotor case 14 via ice, there is a high possibility that the driving rotor and the driven rotor are not so firmly adhesively fixed. In this case, even if the motor 22 suddenly starts rotating at a high rotation speed, the driving rotor 20 and the driven rotor 21 can be sufficiently separated from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14. Then, the inverter device 60 gradually increases the cycle of the starting current when the low-temperature starting mode process is executed. Accordingly, since the motor 22 starts rotating at a faster speed than when the cycle of the starting current is always constant, if the driving rotor 20 and the driven rotor 21 are not fixed to each other so firmly even if they are fixed to the rotor case 14 by ice adhesion, the driving rotor 20 and the driven rotor 21 can be immediately separated from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14. Further, even after the driving rotor 20 and the driven rotor 21 are separated from the ice existing between the driving rotor 20 and the driven rotor 21 and the inner surface of the rotor case 14, the starting current is supplied from the inverter device 60 to the motor 22, but the inverter device 60 gradually increases the cycle of the starting current when the low-temperature start mode process is executed, and thus wasteful power consumption can be suppressed.

In the embodiment, the magnitude of the starting current value, the length of the supply time of the starting current, and the length of the cycle of the starting current when the low-temperature starting mode process is executed may be combined with each other. In short, the time required for starting the pump section P may be shortened as compared with a case where the starting current value and/or the supply time are always set to be constant, and wasteful power consumption may be suppressed.

In the embodiment, the fuel cell pump is a pump for supplying hydrogen to a fuel cell which generates electric power by chemically reacting hydrogen as a fuel gas with oxygen contained in air as an oxidant gas, but may be a pump for supplying air to a fuel cell.

In the embodiment, the fuel cell pump 10 is a roots pump in which the driving rotor 20 and the driven rotor 21 constitute the pump section P, but may be, for example, a cascade pump (centrifugal pump) or a centrifugal pump using an impeller as the pump section P. In short, the fuel cell pump 10 may be configured such that the pump portion P can supply hydrogen as the fuel gas or air as the oxidizing gas to the fuel cell 50.

In the embodiment, the outside air temperature T1 is detected by the temperature sensor 63, but for example, a configuration may be adopted in which the outside air temperature T1 is estimated by detecting the temperature of the rotor chamber 25. In short, any configuration may be used as long as it can estimate the temperature environment outside the fuel cell pump 10.

In the embodiment, the pressure sensor 64 determines whether or not the pump section P is activated, but a torque sensor or the like that detects the torque of the motor 22 may be used. In short, any configuration may be used as long as a detector capable of detecting a change before and after the start of the pump section P is used.

In the embodiment, the pressure sensor 64 determines whether or not the pump section P is activated, but steps S14 and S18 by the pressure sensor 64 may be omitted. That is, in fig. 4, in the case of step S13, if the transition from step S13 to step S15 is not possible, a retry may be performed. In fig. 4, in the case of step S17, if the transition from step S17 to step S15 is not possible, a retry may be performed.

In the embodiment, the driving rotor 20 and the driven rotor 21 may have, for example, a trilobal shape or a quadralobal shape in a cross-sectional view orthogonal to the rotation axis direction of the driving shaft 16 and the driven shaft 17.

In the embodiment, the driving rotor 20 and the driven rotor 21 may have a spiral shape, for example.

The converter device 60 may be configured as a circuit including one or more processors that execute various processes in accordance with a computer program (software). The inverter device 60 may be configured as a circuit including one or more dedicated hardware circuits such as an Application Specific Integrated Circuit (ASIC) that executes at least a part of various processes, or may be configured as a circuit including a combination of one or more processors and one or more dedicated hardware circuits. The processor includes a CPU and a memory such as RAM and ROM. The memory, i.e., the non-transitory computer-readable storage medium, stores program code or instructions configured to cause the CPU to execute the processing. The memory includes all media that can be accessed by the computer, both general and special purpose.