KR20090095530A - Control method of motor system for hybrid fuel cell vehicle with multi-power source and multi-drive system - Google Patents

Abstract

A controlling method of a hybrid fuel cell vehicle is provided to increase the running stability in an emergency using another power source and drive system. A controlling method of a hybrid fuel cell vehicle is as follows. The output power of each motor system independently is controlled based on the efficiency of each motor system satisfying total motor power command value(P mot cmd). The total motor power command value is calculated and transmitted to a motor controller in consideration of the total availability power(P fc avail) and the power available in a secondary power source of a fuel battery based on the total drive demand power(P mot req) in the power controller. A motor system efficiency map stored in the power controller or the motor controller is called. Based on the power controller, the present motor velocity, a total motor power command value, and the motor system efficiency map, the output power of each motor is output.

Description

Control method of motor system for hybrid fuel cell vehicle with multi-power source and multi-drive system

The present invention provides a plurality of power sources and a plurality of drive systems in a hybrid fuel cell vehicle driven by a motor to improve driving stability in an emergency by using a different power source or a different drive system when an error occurs in one power source or one drive system. The present invention relates to a method for controlling a motor system of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system.

In general, a fuel cell is a device for directly converting energy contained in a fuel into electrical energy. In general, a fuel cell having a pair of anodes and cathodes disposed between electrolytes and an ionized fuel gas It is a system that obtains electricity and heat together through electrochemical reaction.

14 is a diagram illustrating a conventional power net applied to a conventional supercap-fuel cell hybrid vehicle.

As illustrated, the fuel cell stack 100 includes a fuel cell stack 100, a super cap 120, an inverter 130, a motor 140, an RGU 150, and a GDU 160.

The fuel cell stack 100, which is widely used for automobiles, is a solid polymer electrolyte fuel cell (PEMFC) having a high power density, and thus, electricity is generated in the polymer electrolyte fuel cell as follows.

Hydrogen gas contained in the fuel of the polymer electrolyte fuel cell desorbs electrons through reaction with a catalyst on the surface of the anode and becomes hydrogen ions. The hydrogen ions pass through the electrolyte membrane and move to the cathode on the opposite side of the anode. The generated electrons move along an external circuit to generate electricity.

The fuel cell stack 100 is composed of a fuel cell system in which two 100 kW fuel cells are connected in series as a main power source for driving a vehicle, and a super cap 120 is capable of fast and high output charging and discharging. As an auxiliary power source, the fuel cell stack 100 can compensate for the shortage of output power and maximize the use of regenerative energy, thereby enabling efficient use of the fuel cell.

Therefore, as described above, the high voltage output from the main power source and the auxiliary power source is converted from direct current to alternating current through the inverter 130 to supply the motor 140 (eg AC 240kW) to drive the vehicle.

Here, as the two fuel cells 100 are connected in series, the main bus terminal 102 is driven at a high voltage (500 to 900 V), and the output torque of the motor 140 is reduced gear unit without a separate stepped gearbox. It is first increased through 150 (Reduction Gear Unit; RGU), and secondly increased through Gear Differential Unit (GDU).

The reduction ratios of the RGU 150 and the GDU 160 are designed to secure climbing performance and to satisfy the oscillation / overtaking performance of a large fuel cell bus.

However, in the fuel cell vehicle using the fuel cell and one large motor 140 connected in series as described above, the maximum speed of the vehicle is limited due to the speed limitation of the large motor 140, and the reduction gear ratio is decreased to increase it. There is a problem that the climbing performance is lowered.

On the contrary, when the RGU 150 and the GDU 160 are designed to have excellent climbing / oscillation / overtaking performance in a fuel cell bus, the maximum speed of the motor is limited, so that the vehicle cannot run more than a certain speed (for example, 80 kph). have.

In addition, when one fuel cell module is abnormal, since the fuel cells 100 are connected in series, both fuel cell modules cannot be used, and thus a situation in which the super cap 120 cannot be used as a substitute for the fuel cell occurs. Done.

However, since the supercap 120 can supplement the deficiency of the output voltage of the fuel cell, it is not possible to continue running the vehicle, and thus the vehicle can be operated only after replacing the abnormal fuel cell module after moving the vehicle to the maintenance center. The series structure of the battery module has a disadvantage in that it is difficult to fundamentally secure driving stability in an emergency.

15 is a power net diagram showing the structure of the Toyota fuel cell bus. The structure of the Toyota fuel cell bus is a 90 kW fuel cell module 110, a DC / DC converter 124, a high voltage battery 123, and an inverter 131. And two passenger fuel cell vehicles in which the motor 141 is mounted in one set.

That is, this structure electrically decouples two sets of passenger fuel cell systems and mechanically merges the outputs of the two motor systems 141 using a power coupling device (154). To achieve.

The PCD 154 has a structure in which gears directly connected to the rear wheel shaft are engaged between gears (spur gears) directly connected to each motor, so that the output of the motor is transmitted to the wheels (rear wheels).

In addition, the structure of the Toyota fuel cell bus increases the amount of power assist and regenerative braking of the large-capacity bus by using two sets of high voltage batteries 123, which are auxiliary power sources, compared to passenger fuel cell vehicles.

Therefore, as the two electrically separated fuel cell systems are used, the voltages of the two main bus stages 112 are driven at low voltages (250 to 450 V), and the output torque of the motor 141 without a separate stepped speed transmission is PCD ( 154 and the gear ratio of the GDU 152 is increased.

However, the hybrid fuel cell bus using the supercap as an auxiliary power source does not require bulky and complicated parts such as the DC / DC converter of the battery-fuel cell hybrid, and precharges to charge the supercap at initial startup. You just need a device.

Therefore, considering that the fuel cell takes a large part in the production cost and packaging aspects of the fuel cell bus, there is a limit in increasing the maximum output power of the motor due to layout problems as well as an increase in manufacturing cost due to the increase in fuel cells. .

On the other hand, Figure 16 shows a fuel cell bus using a single fuel cell 101 and a single large motor 143, a single large capacity using only the fuel cell system 101 of about 205kW class without an auxiliary power source such as supercap The system which supplies electric power to the motor 143 is employ | adopted. In this case, the motor output is connected to the manual transmission 153 and adopts a structure capable of stepping shift by a driver.

However, the power net structure of the fuel cell bus as described above does not use a secondary power system such as a battery or a supercap, and thus, it is impossible to assist power, so that the fuel cell system may be excessively operated, and thus the durability life may be reduced. There is a disadvantage in that energy efficiency is low because it can not absorb energy.

In addition, since only one fuel cell system and a large-capacity motor 143 are used, there is a disadvantage in that it is difficult to fundamentally secure driving stability in an emergency associated with abnormal operation of the fuel cell system 101 or the motor system 143.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and is provided with a plurality of power sources and a plurality of drive systems, and in the event of an abnormality in one power source or one drive system, another power source or another drive system is used to provide driving stability in an emergency. It is an object of the present invention to provide a method for controlling a motor system of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system, which can be improved.

In addition, the present invention by connecting a plurality of main power source and auxiliary power source in parallel to share one main bus stage, it is possible to further increase the number of motors while maintaining the existing plurality of main power source, the motor It is possible to improve the climbing performance by increasing the output torque of the hybrid fuel cell vehicle.The hybrid fuel cell vehicle having a multi-power source and a multi-drive system can improve fuel efficiency as well as shorten the arrival time compared to the same speed when starting and passing. Another purpose is to provide a motor system control method.

In addition, the present invention can maintain the maximum output torque without dropping the output torque of the motor even if one additional motor of the drive system by using the torque transmission means to improve the output performance of the motor and the power performance of the vehicle Another object is to provide a method for controlling a motor system of a hybrid fuel cell vehicle having a power source and a multi-drive system.

The present invention for achieving the above object is a hybrid fuel cell vehicle,

A plurality of main power sources sharing one main bus stage and connected in parallel with each other;

A plurality of drive systems which receive power from the main bus stage to drive wheels and generate output torques, and connected in parallel to each other; And

It is installed between the main power source and the drive system to compensate for the power shortage of the main power source, it characterized in that it comprises an auxiliary power source sharing the main bus stage.

In a preferred embodiment, the main power source is characterized in that the fuel cell.

In a more preferred embodiment, the auxiliary power source is characterized in that it comprises a supercap and a precharge device used for initial charging from the fuel cell.

The auxiliary power source may include a battery and a bidirectional DC / DC converter.

In addition, the plurality of drive systems connected in parallel are characterized in that each made of a motor.

The plurality of drive systems may include at least first to third motors, and power of the main bus terminal may be independently supplied to the motor through an inverter.

In addition, it characterized in that it further comprises a gear means for incorporating the first to third motor to increase the output torque output from the drive system to the wheel to a certain gear ratio.

In addition, the gear means is a power connection device that the output shaft of the first and third motors are directly connected to the input so that the first to third motors all have the same torque increase ratio, the second motor is merged through the reduction gear unit (RGU). (PCD); And

It characterized in that it comprises a universal joint for connecting the final output shaft of the PCD to the gear differential (GDU).

In particular, the RGU is made of a combination of planetary gears, the output shaft of the second motor is connected to the sun gear of the RGU, the ring gear is fixed, the carrier shaft is coupled to the PCD to increase the torque of the second motor through the carrier Characterized in that the installation is made.

Another aspect of the invention is a control method of a hybrid fuel cell vehicle having a plurality of power sources and a plurality of drive systems,

Determining whether to use some (mil mode) or all (power mode) of the plurality of power sources by using the push button of the driver or the automatic recognition of the driving pattern of the controller; And

When the current driving state of the vehicle is a mild mode, only a part of the plurality of power sources are started, and in the power mode, a plurality of power sources are all started to drive according to each corresponding mode.

The method may further include determining whether some of the plurality of power sources or drive systems need to be stopped during the normal driving in the mild mode or the power mode (significant defect occurrence); And

In the event of a major fault, stopping some of the power sources or drivetrains that need to be shut down, starting the power sources that were off, or driving in an emergency mode using the power sources and drivetrains that did not have significant faults; It is characterized by comprising.

In a preferred embodiment, the method may further include determining whether the mild mode or the power mode operation is appropriate when the serious defect does not occur.

In a more preferred embodiment, the step of determining whether the mild mode or power mode operation is appropriate for the three control variables, the driver's acceleration through the accelerator pedal opening history, the total using the motor speed-torque characteristic map It is characterized in that the check using the required driving power, the power source available power.

In addition, when the accelerator pedal opening history is kept below a certain value during the driving in the mild mode, and the total driving demand driving force is maintained within a range of the available power source available power, the driving in the mild mode is continued, and If not satisfied, switch to power mode.

If the accelerator pedal opening history is kept below a certain value while driving in the power mode, and the total driving demand power is maintained within the range of some of the power source available power being used, the mode is converted to the mild mode, and the condition is not satisfied. If the case is characterized by continuing the power mode driving.

Another aspect of the present invention is a motor system control method for a hybrid fuel cell vehicle having a multi-power source and a multi-drive system,

In order to satisfy the total motor power command value (P_mot_cmd), each motor system is characterized by independently controlling the output power of each motor system in consideration of efficiency.

As a preferred embodiment, the motor controller is calculated by calculating the total motor power command value in consideration of the total available power P_fc_avail of the fuel cell and the power available from the auxiliary power source based on the total drive required power P_mot_req in the power controller PCU. Transmitting to the MCU;

Calling a motor system efficiency map stored in the PCU or MCU;

Deriving output power of each motor based on a current motor speed, a total motor power command value, and a motor system efficiency map in the PCU; And

The PCU is characterized in that it comprises the step of transmitting the output power of each motor to the MCU.

In a more preferred embodiment, after deriving the output power of each motor based on the current motor speed, the total motor power command value, the motor system efficiency map in the PCU, the PCU output power of each motor when the motor is motored It is characterized by controlling the sum (positive number) of the values divided by the efficiency of each motor to minimize the value calculated over time.

Further, after deriving the output power of each motor based on the current motor speed, the total motor power command value, and the motor system efficiency map, the PCU determines the output power of each motor when regenerative braking of the motor is performed. It is characterized by controlling the sum (negative) of the values multiplied by the efficiency by minimizing the value calculated over time.

As described above, according to the motor system control method of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system according to the present invention, a power source or drive system of one of the power source or drive system using a plurality of power sources and at least three drive systems. In case of abnormal operation, emergency operation can be performed by using another power source or drive system connected in parallel, thereby securing driver and passenger safety.

In addition, since a plurality of power sources share one main bus stage, it is possible to further configure at least three drive systems while maintaining the capacity of the conventional power source, so that the climbing performance is significantly increased compared to the existing power source having the same capacity. Not only is it effective, it also has the advantage of improving top speed and oscillation / overtaking performance.

In addition, the main bus stage is shared using a minimum of fuel cells (eg, two) without increasing the number of parallel connected fuel cell systems to drive three or more drive systems. Because of the structure for supplying power to three or more drive systems, it is possible to reduce the material cost by reducing the number of use of the fuel cell.

In addition, it is easy to maintain and reduce the replacement cost by replacing only some fuel cell systems and some motor systems in which problems occur due to endurance life limitations and driving failures.

In addition, it is possible to reduce the total volume and weight of the three or more multi-drive system, compared to the volume / weight of one large motor, and a distributed package using the dead volume of the vehicle according to the parallel connection of the power source.

Finally, powering off part of a number of paralleled fuel cell systems or part of three or more motor systems in normal (for mild driving with low driving force requirements) or by performing idle stop control improves fuel economy and increases the service life of the system. Is possible.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

1 is a block diagram illustrating a power net of a hybrid fuel cell vehicle according to an exemplary embodiment of the present invention.

Fuel cells used as main power sources in conventional hybrid fuel cell vehicles generally have a one-way direction, and thus generate electricity and water through electrochemical reactions by receiving hydrogen and oxygen, but cannot store or charge electric energy. .

Therefore, when only the fuel cells 10 and 11 are used as the main power source, the fuel cells 10 and 11 are excessively used, thereby deteriorating durability, and in particular, one fuel cell 101 or a plurality of fuel cells 100. If the are connected in series, the entire system will shut down beyond one fuel cell or part of the fuel cell, causing serious consequences for the vehicle to stop.

In addition, since the fuel cell itself is expensive to manufacture, the fuel cell vehicle takes up a large portion of the manufacturing cost of the fuel cell vehicle, and also consumes a lot of additional costs such as a BOP (balance of plant) for using the fuel cell system. In terms of efficiency, it can not be considered.

Considering this situation, the use of auxiliary power sources other than the main power source such as fuel cells is indispensable in conjunction with the demands of the times to increase the use of environmentally friendly fuel cell vehicles.

The fuel cell system used in the current fuel cell bus is a case of using a single fuel cell 101 in 200kW class or two 100kW fuel cell 100 connected in series.

In addition, the battery 23 and the supercaps 20 and 21 may be used as auxiliary power sources in a fuel cell vehicle.

When the battery 23 is used as an auxiliary power source, the battery 23 and the fuel cell are connected in parallel between the fuel cell 10 and the battery 23 to supply a stable voltage to the motors 41 to 43. The bidirectional DC / DC converter 24 which matches the balance of the different output voltages of 10 and provides the surplus voltage and the regenerative braking energy of the fuel cell 10 as the charging voltage of the battery 23 is provided. Included.

When the supercaps 20 and 21 are used as auxiliary power sources, the motor cap is compensated for by using the supercaps 20 and 21 to compensate for the shortage of the fuel cell output power, and the DC / DC converter of the battery-fuel cell hybrid ( The bulky and complicated control parts are eliminated as shown in 24).

Here, the present invention provides a plurality of power sources and a plurality of drive systems.

As described above, when one power source or a plurality of fuel cells are used in series, it is impossible to secure driving stability when an error occurs in one power source or fuel cell.

In order to solve such a problem, a plurality of power sources, that is, fuel cells 10 and 11 may be used.

However, as described above, since the fuel cell is expensive, the maximum output power of the fuel cell is inevitably limited, and when the fuel cell used in the fuel cell bus is 200kW, a plurality of fuel cells are maintained while maintaining the existing output. In order to use the power source of the 200kW class can only be separated into two 100kW (Fig. 1).

Of course, the 200 kW fuel cell 11 may be divided into four 50 kW (FIG. 2). In the present invention, the basic configuration of the primary power supply system is divided into a plurality of fuel cells 10 and 11 while maintaining the power amount of the existing fuel cell, and the plurality of divided fuel cells 10 and 11 are arranged in parallel. It is connected and is characterized in that one main bus stage 12 is shared.

As such, when a plurality of fuel cells 10 and 11 are connected in parallel to two 100 kW or four 50 kW and one main bus stage 12 is configured, one large fuel cell 101 or a fuel cell connected in series ( It is 250 ~ 450V which is cut in half compared to 100).

However, in the case of a vehicle equipped with a polymer electrolyte fuel cell stack of 80 to 90 kW, the output range of 0 to 5 kW in the start, deceleration or stop mode, and the output range of 10 to 15 kW in the constant speed drive, In the climbing and acceleration modes, it has an output range of 20 to 90 ,, so even if the voltage supplied through the output of the fuel cell is reduced by half compared to the existing large capacity or series-connected fuel cell 100, start / deceleration / stop and constant speed driving It doesn't matter at all.

Instead, in order to increase the output performance in the starting, climbing, and acceleration modes, the driving torque of the vehicle may be increased by adding a plurality of driving systems, that is, the motor 43, in the starting / climbing / accelerating mode.

In the conventional fuel cell bus, the output performance is improved when the three drive motors 41 to 43 are mounted in the present invention than when the two motors 41 and 42 are mounted.

In addition, although the present invention may use the battery 23 as an auxiliary power source, in the present invention, as described above, it is preferable to use the supercaps 20 and 21 as auxiliary power sources. At this time, two supercaps 20 of 19.4F may be used as auxiliary power sources (FIGS. 1 and 2), and one supercap 21 of 38.8F may be used (FIG. 3).

In addition, the voltage output from the main power source or the auxiliary power source to one main bus stage 12 is converted from direct current to alternating current through inverters 31 to 33 to supply power suitable for use by the motors 41 to 43. Will be.

The drive system according to the present invention uses three or more motors 41 to 43 that are independently controllable and connected in parallel. As an embodiment, three inverters and a motor are connected in parallel to one main bus stage 12. The voltage of the main bus stage 12 is independently supplied to the 100 kW class motors 41 to 43, respectively, and the reduction gear unit 51 (RGU; Reduction Gear Unit) and the power connecting device 52 (PCD; Power Coupling Device) And a gear differential unit 53 (GDU; Gear Differential Unit).

As shown in FIG. 6, the driving system according to an embodiment of the present invention includes three motors (first to third motors; 41 to 43) connected in parallel by sharing one main bus stage 12, and a first one. And a PCD 52 in which output shafts of the third motors 41 and 43 are directly connected to the input, and the second motor 42 is merged through the RGU 51.

The torques of the first motor 41 and the third motor 43 are equally increased through the constant gear ratio of the PCD 52, and the torque of the second motor 42 is the first motor via the RGU 51. It is configured to be increased in the same manner as the torque of the 41 and the third motor 43.

Here, the RGU 51 is used to raise the torque of the second motor 42 to the maximum, and may be implemented as a combination of planetary gears together with the PCD 52.

That is, as shown in FIG. 6, the output shaft of the second motor 42 is connected to the sun gear 55 of the RGU 51, the ring gear 56 is fixed, and the carrier shaft is coupled to the PCD 52. The torque of the second motor 42 is increased through the furnace carrier 57. In this case, the gears of the RGU 51 and the PCD 52 are designed such that the first to third motors 41 to 43 have the same torque increasing ratio. In addition, the final output shaft via the PCD 52 is coupled via the GDU 53 and the universal joint 54.

In addition, the reason why the second motor 42 is coupled to the PCD 52 through the RGU 51 is, for example, when the first to third motors 41 to 43 are 100 kW, respectively. When the 42 is directly connected to the PCD 52, the vehicle driving torque cannot be maximized and the maximum speed of the vehicle is limited by the maximum rotation speed of the second motor 42. Therefore, the first to third motors 41 to 43 ) Are all equally increased with the same gear ratio, so as to maximize the vehicle drive torque while significantly easing the maximum vehicle speed limit.

In addition, the reduction ratios of the RGU 51, the PCD 52, and the GDU 53 are designed to ensure high climbing performance, the highest speed, and the oscillation / overtaking performance.

According to another embodiment of the present invention, as shown in FIG. 7, four motors (first to fourth motors 41 to 44) connected in parallel by sharing one main bus stage and two motors ( The first and third motors 41 and 43 and the second and fourth motors 42 and 44 include two-row gear parts 62 and 63 connected between the two motors so as to be directly connected in series.

That is, the first to fourth motors 41 to 44 are merged through the second row gear parts 62 and 63, and the second row gear parts 62 and 63 are designed so that the motors can all be increased at the same torque ratio. That's the way. In this case, the fourth motor 44 may be excluded. In addition, the final output shafts of the second row gear parts 62 and 63 are coupled via the GDU 53 and the universal joint 54.

As described above, the driving system of the present invention has been described an embodiment in which three and four motors are used to improve the output performance of the vehicle, but it is apparent that more than one motor can be used by the embodiment of the present invention. .

2 to 4 are configuration diagrams of a power net showing a modification of a fuel cell vehicle using a multi power source and a multi drive system according to the present invention.

FIG. 2 shows a supercap of 19.4F connected in parallel between four fuel cells 11 and fuel cells 11 and motors 41 to 43 of 50 kW connected in parallel for use as a main power source. (20) It comprises two, three 100kW motors (41 ~ 43) used for driving the vehicle.

3 is a supercap of 38.8F for two fuel cells 10 of 100 kW connected in parallel to be used as the main power source, a parallel connection between the fuel cell 10 and the motors 41 to 43 and for use as an auxiliary power source. 21, three 100kW motors 41 to 43 used for driving the vehicle.

4 shows two fuel cells 10 of 100 kW connected in parallel for use as a main power source, a battery 23 for use as an auxiliary power source and connected in parallel between the fuel cells 10 and the motors 41 to 43. Two, and a DC / DC converter 24, and three 100kW motors 41 to 43 for use for driving the vehicle.

The operation state of the hybrid fuel cell vehicle having the multi-power source and the multi-drive system according to the present invention having such a configuration will be described below with an example.

In the fuel cell-supercap hybrid vehicle according to the present invention, the plurality of fuel cells 10 share one main bus stage 12, and the super cap 20 shares the main bus stage 12 to provide a fuel cell ( The power shortage of 10) is compensated for, and the voltage of the main bus stage 12 output from the fuel cell 10 or the super cap 20 is independently of the plurality of motors 41 to 43 through the inverters 31 to 33. At this time, the torque of the first motor 41 and the third motor 43 is increased by the gear ratio of the PCD 52 to be transmitted to each wheel through the GDU 53, the torque of the second motor 42 Through the RGU 51, the PCD 52, and the GDU 53, the torque is increased to be equal to the torque of the first and third motors 41 and 43 and transmitted to the wheels.

In the case of the fuel cell-battery hybrid vehicle according to another embodiment of the present invention, it is similar to the operation of the fuel cell-supercap hybrid vehicle.

In addition, in a hybrid fuel cell vehicle using the battery 23 or the supercaps 20 and 21 as auxiliary power sources, the motors 41 to 43 may be RGU 51, PCD 52, and GDU 53 from each wheel when regenerative braking is performed. Receives kinetic energy through) to generate electrical energy to be stored in the battery 23 or the supercaps (20, 21).

The present invention by such a configuration and action using a plurality of power sources and at least three drive system emergency operation using another power source or drive system connected in parallel when one of the power source or drive system of the drive system or drive system is abnormally operated. This makes it possible to secure the safety of the driver and the passenger.

In addition, since a plurality of power sources share one main bus stage 12, it is possible to additionally configure at least three drive systems while maintaining the capacity of the conventional power source, thereby increasing the climbing performance compared to the existing power source having the same capacity. Not only is it a much higher effect, it also has the advantage of improving top speed and oscillation / overtaking performance.

In addition, the main bus stage (eg, two) using a minimum number of fuel cells 10 (for example, two) without increasing the number of parallel connected fuel cell systems to drive three or more drive systems. Since 12) is shared and power is supplied to three or more drive systems, it is possible to reduce material costs by reducing the number of uses of the fuel cell 10.

In addition, it is easy to maintain and reduce the replacement cost by replacing only some fuel cell 10 systems and some motors 41 to 43 in which a problem occurs due to a durability life limit and a malfunction.

In addition, it is possible to reduce the total volume and weight of the three or more multi-drive system, compared to the volume / weight of one large motor, and a distributed package using the dead volume of the vehicle according to the parallel connection of the power source.

Finally, a part of a plurality of parallel-connected fuel cell systems 10 or a part of three or more motors 41 to 43 are usually powered off (in case of mild driving with low driving force required for driving) or by performing idle stop control. It is possible to improve and increase the service life of the system.

Meanwhile, a control method of a hybrid fuel cell vehicle having a multi power source and a multi drive system according to the present invention will be described.

The control logic according to the present invention has five modes, (1) Mild mode, which uses some of the multi-power sources (e.g., fuel cell 10), (2) Power using all of the multi-power sources. (3) Mode to switch to power mode, and (4) Mode to switch to mild mode when judging whether the driving mode is appropriate or not. 5) It can be divided into emergency mode.

First, after the key-on, by using the driver's push button or the automatic recognition of the driving pattern by the controller, the mild mode or the power mode is initially determined after starting.

In this case, the push button is installed around the driver's seat so that the driver can manually operate by judging the driving state, and normally the driving pattern is automatically recognized by the controller, but is used when the user needs to check or specially operate the push button. .

Driving pattern automatic recognition function associated with the mild / power mode in the present invention is a vehicle key The mode used immediately before the key off is stored in the controller buffer and used as it is when the next key on of the vehicle is used, and the mode history used immediately before the key off of the vehicle (1 to 3). ) And the mode history (about 1 to 3) used at the next key-on of the vehicle to the controller to use the mode history that was used just before the vehicle key-off as input and to use the key-on as output. The method of determining a mode (mild or power mode).

In the mild mode or the power mode determination step, in the power mode, all the power sources are started to start the normal driving in power mode. In the mild mode, only some of the multi power sources are started to start the normal driving in the mild mode.

After a certain period of time, when driving in mild mode, the vehicle is continuously checked for adequacy of driving in mild mode, and the check method includes three control variables, for example, the driver's acceleration will (eg, accelerator pedal opening history, etc.). Range of the total available power of some fuel cells 10 and 11 in which the opening history of the accelerator pedal is kept below a certain value and the total driving demand is used by utilizing the total driving demand power and the available power of the fuel cell. If it stays within, it will continue to drive in mild mode, and if the situation continues to violate these conditions, it will switch to power mode.

The mode conversion of the present invention is automatically performed while driving or stopping the vehicle. In the mild mode, all of the fuel cells 10 and 11 which are turned off through mode switching are started to supply power.

Applying a similar method to the above-mentioned mild mode to power mode check and auto conversion method while driving in power mode, the accelerator pedal opening history is kept below a certain value by using three control variables. If the situation where the power is maintained in a range sufficiently lower than the total available power of the entire fuel cells 10 and 11 continues, the conversion to the mild mode is performed.

As described above, the mode conversion of the present invention is automatically performed while driving or stopping the vehicle. Part of the fuel cells 10 and 11 which are entirely turned on through the mode conversion are turned off and the fuel cells 10 which are on remainder are turned on. Only 11) will supply power.

Herein, the configuration of a controller and a control method thereof for converting a mild mode to a power mode or a power mode to a mild mode of the present invention will be described in detail.

As shown in FIG. 8, the vehicle control unit (VCU) 71 is a vehicle controller, which utilizes a motor speed-torque characteristic map stored in a look-up table format as an input of an Excel position sensor (APS) and a motor speed. To output the total driving demand force (P_mot_req).

In this case, P_mot_req is calculated in consideration of the outputs of all three motors regardless of whether they are currently used or not.

In addition, the VCU 71 derives the driver's acceleration will based on the Excel position sensor. In the present embodiment, the VCU 71 is denoted as Excel. For example, the Excel signal is an Excel position to reflect the operator's acceleration will. Means a signal filtered based on the sensor signal.

The fuel cell control unit (FCU 72) is a fuel cell controller that operates multiple fuel cells (e.g., only some of the fuel cells operate in the mild mode, and all the fuel cells operate in the power mode). The total available power P_fc_avail of the fuel cell is output according to the conditions (eg, cell voltage adequacy according to temperature, pressure, flow rate, humidification, etc.).

The PCU 73 (Power Control Unit) is a power controller or hybrid controller and continuously determines whether the mild mode and the power mode are appropriate based on three input variables (Accel, P_mot_req, and P_fc_avail).

That is, when driving in the mild mode, the situation that Excel> Excel_high (acceleration threshold of the driver's acceleration determination) or P_motor_req> P_fc_avail_mild occurs a certain number of times or more than a certain duration (hatched section of Fig. 9). To switch from mild mode to power mode. However, in order to prevent frequent mode change, the next mode change is allowed only after a certain time after performing one mode change (applied to some kind of hysteresis).

In addition, when driving in the power mode (Accel) <= Excel High and P_motor_req <= P_fc_avail_mild occurs a certain number of times, more than a certain duration (hatched in Figure 9), the power mode to mild mode. However, to prevent frequent mode changes, the next mode change is allowed only after a certain time after performing one mode change (applied to some kind of hysteresis).

By the method described above, it is determined whether the mild mode and the power mode are appropriate, and as a result (FC_onoff_cmd) is transmitted to the FCU to control only a part of the total fuel cells (mild mode) or start all of the fuel cells. To perform.

If some of the multi-power sources or some of the multi-drive systems need to be shut down (when a serious defect occurs) while driving in the mild mode or power mode, after a certain time has elapsed, some power sources or some drive systems with a serious defect have been shut down and turned off. The fuel cells 10 and 11 are started, or the control logic for using a power source and a drive system that does not have a serious defect is automatically converted to perform emergency mode driving.

Here, the mode change during the mild mode or the power mode driving may be performed by either or both of adequacy of driving and determination of occurrence of a serious defect.

In addition, the PCU 73 transmits the total motor power command value (P_mot_cmd) to the MCU 74 (Motor Control Unit, Motor Controller) in consideration of the power available from P_fc_avail and auxiliary power sources (eg, supercaps) based on P_mot_req. do.

Meanwhile, the control method of the multi-motor system according to the present invention independently controls the output power of each motor system (eg, three or more) in consideration of the efficiency of each motor system to satisfy the total motor power command value. In this case, the motor system refers to the inverters 31 to 33 and the motors 41 to 44 connected in parallel to receive power from the main bus stage 12 shared by the multi-power sources.

For example, as shown in FIG. 10, when P_mot_cmd is 120kW and the total required torque is 300Nm at a given motor speed, the efficiency of each motor system is equal to 80 when the power is equally distributed to each of the three motors with an output of 40kW and a torque of 100Nm. %, While outputting 60 kW each using two motors (first and third motors) (each torque equals 150 Nm), and the remaining motors (eg second motors) are idle (equivalent to 0 Nm) The efficiency of each system is 90%, which improves the energy efficiency of the entire multi-motor system.

Here, the reason why the total motor power command value is evenly distributed to only two of the three motors is less than that of three motors. In order to improve the fuel efficiency by improving the efficiency of the motor system by distributing to the motor system having a relatively good efficiency without distributing or distributing the motor power command value to the efficient motor system.

Therefore, if the output power of each motor system is independently controlled in consideration of the efficiency of each motor system, more power is output to the wheel even if the same power is input in terms of energy efficiency by increasing the degree of freedom in selecting the motor systems connected in parallel. I can supply it.

Referring to the control method of the multi-motor system of the present invention in more detail as follows. 11 is a flowchart illustrating a control method of a multi-motor system according to an exemplary embodiment of the present invention.

In the control method of the multi-motor system according to the present invention, after deciding which mode to operate in the mild mode or the power mode, the output power of each motor system is independent in consideration of the efficiency of each motor system to satisfy the total motor power command value. How to control.

The total motor power command value is calculated in consideration of the total available power of the fuel cell and the power available from the auxiliary power source (eg, supercap) based on the total required driving power using the motor speed-torque characteristic map.

Therefore, what should be done for the control of the multi-motor system is to calculate the total motor power command value in consideration of the total available power of the fuel cell and the power available from the auxiliary power source based on the total drive required power.

Then, the motor system efficiency map stored in the PCU 73 or the MCU 74 is called. Subsequently, the PCU 73 derives the output power of each motor based on the current motor speed, P_mot_cmd, and the motor system efficiency map.

At this time, when motoring (P_mot_cmd positive), the power command value of each motor is divided by the efficiency of each motor, then the sum of all the result values are minimized, and when regenerative braking of the motor (P_mot_cmd negative) Each motor is controlled by multiplying the power command value of each motor by the efficiency of each motor, and then minimizing the sum of all the resulting values.

Here, dividing the power command value of each motor by the efficiency of each motor when motoring the motor indicates directionality, which means that the power is supplied from a multi-power source and proceeds in a direction to be transmitted to each wheel of the vehicle through the motor. The output value is positive), and 'MINimize' means more power in terms of energy efficiency by minimizing the motor power command value (input value) that controls each motor.

In addition, multiplying the power command value of each motor by the efficiency of each motor during regenerative braking of the motor means that the kinetic energy is supplied from each wheel of the vehicle and proceeds in a direction in which energy is stored in the auxiliary power source through the motor (output value of the motor). MINimize means to increase the stored energy of the auxiliary power source by minimizing the kinetic energy (output value) from each wheel in terms of energy storage efficiency. It means.

Hereinafter, the present invention will be described in more detail based on the following examples, but the present invention is not limited by the following examples.

Comparative example

12B and 13B are graphs showing a case where the total motor power command value is evenly distributed to each motor system.

Assuming that the total motor power command value (P_mot_cmd) increases linearly from 0 to 300 kW over time, if the total motor power command value is evenly distributed to three motors, the power command value distributed to each motor is 0. It increases linearly from 0 ~ 20kW in ~ t1 section, 20 ~ 40kW in t1 ~ t2 section, 40 ~ 60kW in t2 ~ t3 section and 60 ~ 100kW during t3 ~ t4.

Example 1

12A is a graph showing total motor power command values for a multi-motor system according to an embodiment of the present invention, and FIG. 12C is a graph showing motor power command values of each motor system to a multi-motor system according to an embodiment of the present invention. .

Assuming that the total motor power command value (P_mot_cmd) increases linearly from 0 to 300 kW over time, when the total motor power command value is independently controlled by three motors, the power command value distributed to the first motor is 0 ~ 60kW in 0 ~ t1 section, 60kW in t1 ~ t2 section, 60kW in t2 ~ t3 section, 60 ~ 100kW during t3 ~ t4.

The power command value distributed to the second motor is linearly increased to 0 kW in the 0 to t1 section, 0 to 60 kW in the t1 to t2 section, 60 kW in the t2 to t3 section, and 60 to 100 kW during t3 to t4.

The power command value distributed to the third motor is linearly increased to 0 kW in the 0 to t1 section, 0 kW in the t1 to t2 section, 0 to 60 kW in the t2 to t3 section, and 60 to 100 kW during t3 to t4.

Example 2

13A is a graph showing total motor power command values for a multi-motor system according to another embodiment of the present invention, and FIG. 13C is a graph showing motor power command values for each motor system to a multi-motor system according to another embodiment of the present invention. .

Assuming that the total motor power command value (P_mot_cmd) increases linearly from 0 to 300 kW over time, when the total motor power command value is independently controlled by three motors, the power command value distributed to the first motor is 0 ~ 60kW in 0 ~ t1 section, 30 ~ 60kW in t1 ~ t2 section, 40 ~ 60kW in t2 ~ t3 section, 60 ~ 100kW during t3 ~ t4.

The power command value distributed to the second motor is linearly increased to 0 kW in the 0 to t1 section, 30 to 60 kW in the t1 to t2 section, 40 to 60 kW in the t2 to t3 section, and 60 to 100 kW during t3 to t4.

The power command value distributed to the third motor is linearly increased to 0 kW in the 0 to t1 section, 0 kW in the t1 to t2 section, 40 to 60 kW in the t2 to t3 section, and 60 to 100 kW during t3 to t4.

While the invention has been shown and described with respect to certain preferred embodiments thereof, the invention is not limited to these embodiments, and has been claimed by those of ordinary skill in the art to which the invention pertains. It includes all the various forms of embodiments that can be carried out without departing from the spirit.

1 is a block diagram of a power net of a hybrid fuel cell vehicle according to an exemplary embodiment of the present invention.

2 is a power net diagram of a hybrid fuel cell vehicle according to another embodiment of the present invention.

3 is a configuration diagram of a power net of a hybrid fuel cell vehicle according to still another exemplary embodiment of the present invention.

4 is a configuration diagram of a power net of a hybrid fuel cell vehicle according to still another exemplary embodiment of the present invention.

5 is a flowchart illustrating a method of controlling a hybrid fuel cell vehicle according to an embodiment of the present invention.

Figure 6 is a block diagram showing a gear means according to an embodiment of the present invention.

Figure 7 is a block diagram showing a gear means according to another embodiment of the present invention.

8 is a block diagram of a control device for a hybrid fuel cell vehicle having a multi-power source and a multi-drive system of the present invention.

9 is a graph showing an Excel opening history, a total driving demand force, and a total available power of a fuel cell for determining whether a mode is appropriate in a fuel cell vehicle according to an exemplary embodiment of the present invention.

10 is a conceptual view illustrating a control method of a multi-motor system according to an embodiment of the present invention.

11 is a flowchart illustrating a control method of a multi-motor system according to an embodiment of the present invention.

12A to 12C are conceptual views illustrating an independent control method of each motor in a multi-motor system according to an embodiment of the present invention.

13A to 13C are conceptual views illustrating an independent control method of each motor in a multi-motor system according to another exemplary embodiment of the present invention.

14 is a configuration diagram of a power net of a hybrid fuel cell bus according to a conventional embodiment.

15 is a block diagram of a power net of a hybrid fuel cell bus according to another exemplary embodiment of the prior art.

16 is a configuration diagram of a hybrid fuel cell bus according to another conventional embodiment of a power net.

<Description of the symbols for the main parts of the drawings>

10,11 fuel cell 12 main bus stage

20,21: Supercap 23: Battery

24: DC / DC converter 31 ~ 33: inverter

41 ~ 43: 1st to 3rd motor 51: Reduction gear part (RGU)

52: power connection device (PCD) 53: gear differential (GDU)

54: universal joint 55: sun gear

56 ring gear 57 carrier

62,63: two-row gear section 71: VCU

72: FCU 73: PCU

74: MCU

Claims (3)

In the motor system control method of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system in which each motor system independently controls the output power of each motor system in consideration of efficiency in order to satisfy the total motor power command value (P_mot_cmd), Based on the total driving demand (P_mot_req) of the power controller (PCU), the total motor power command value is calculated and transferred to the motor controller (MCU), taking into account the total available power (P_fc_avail) of the fuel cell and the power available from the auxiliary power source. Making; Calling a motor system efficiency map stored in the PCU or MCU; Deriving output power of each motor based on a current motor speed, a total motor power command value, and a motor system efficiency map in the PCU; Transmitting output power of each motor to the MCU in the PCU; Motor system control method for a hybrid fuel cell vehicle having a multi-power source and a multi-drive system, characterized in that comprises a. The method according to claim 1, After deriving the output power of each motor based on the current motor speed, the total motor power command value, and the motor system efficiency map in the PCU, the PCU converts the output power of each motor to the efficiency of each motor when the motor is motored. A method for controlling a motor system of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system, characterized in that the sum of the divided values (positive number) is minimized and controlled. The method according to claim 1, After deriving the output power of each motor based on the current motor speed, the total motor power command value, and the motor system efficiency map, the PCU calculates the output power of each motor when regenerative braking of the motor is performed. A method for controlling a motor system of a hybrid fuel cell vehicle having a multi-power source and a multi-drive system, characterized in that the sum of the multiplied values (negative) is minimized and controlled.

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