KR101090814B1 - Control apparatus and method of vehicle with multi drive system - Google Patents

Abstract

PURPOSE: An apparatus for controlling a vehicle with a multi drive system and a controlling method thereof are provided to stably operate a vehicle by controlling the speed and torque of a motor to be the mean value of a monitored voltage in each driving system which comprises a multi drive system. CONSTITUTION: A multi drive system has a plurality of driving systems. A fuel cell stack(10) is a power source. A super cap(20) supports the output of the fuel cell stack. The super cap charges a regenerative braking energy. One or more inverters change a DC voltage, which is provided in the fuel cell stack and the super cap, to a three phase voltage.

Description

CONTROL APPARATUS AND METHOD OF VEHICLE WITH MULTI DRIVE SYSTEM}

The present invention relates to a vehicle having a multi-drive system, and more particularly, to a control apparatus and method for a vehicle having a multi-drive system to perform the voltage and torque control using the average value of the voltage monitored in the plurality of drive systems. will be.

A fuel cell is a type of power generation system that directly converts chemical energy of a fuel into electrical energy. The fuel cell is composed of a unit cell composed of a pair of anode and cathode electrodes interposed between electrolytes. do.

By supplying hydrogen to the anode of the unit cell using a balance of plant (BOP) and oxygen to the cathode to generate electricity and heat through the chemical reaction of the ionized material.

Since the fuel cell does not undergo the combustion (oxidation) reaction of fossil fuel, it does not emit harmful substances such as NOx, SOx, HC, and CO, and it is evaluated as a future power generation technology because of its high generation efficiency and energy saving and environmental pollution problem. In order to cope with the recent global warming problem, it has been applied as a power source of vehicles.

In a vehicle using a fuel cell as a power source, the maximum speed of the vehicle is limited due to the speed limit of the motor, and when the reduction gear ratio is reduced to solve the limitation of the maximum speed, the climbing performance is deteriorated.

Accordingly, in order to secure a large driving torque, a multi-drive system including an inverter which cross-connects and connects a plurality of motors and controls the driving of the motor corresponding to each of the plurality of motors is provided.

The multi-drive system is typically composed of three motors, and has a structure of a power coupling device (PCD) for transmitting a driving force to one axis by engaging gears respectively coupled to the rotating shaft of the motor.

Since the multi-drive system typically has three independent drive systems, emergency operation is possible using another drive system that maintains normal when one or two drive systems have abnormalities.

In the multi-drive system, when the DC voltage output from the fuel cell stack is supplied to the inverter forming the independent drive system, the inverter is switched according to the control signal of the controller to convert the DC voltage into a three-phase voltage to drive the motor disposed in the independent drive system. Supply with voltage.

At this time, the controller monitors the DC voltage supplied to the inverter in the fuel cell stack by using a voltage sensor installed in the inverter. When the DC voltage supplied to the inverter is lower than the set minimum voltage value, the controller controls each inverter. Limit the drive voltage output to the motor.

Therefore, a problem arises in that the output of the motor is executed and the output of the vehicle falls.

In addition, since the voltage sensor has an error, the voltage supplied to the inverter in the fuel cell stack may be measured by reflecting the error of the voltage sensor, but the error range of the voltage sensor is different from each other in the mass production process. The error causes a problem that causes a great influence on the output of the vehicle.

For example, when the actual voltage of the fuel cell stack is 262V, the voltage supplied to the inverter of the first drive system is 262V, the voltage supplied to the inverter of the second drive system is 259V, and the voltage supplied to the inverter of the third drive system is It is assumed that it is detected as 264V and the output limit voltage is set to 260V.

Although the actual stack voltage is out of the output limit range of 262V, the voltage supplied to the inverter of the second drive system is monitored at 259V, which is lower than the output limit voltage 260V due to the error of the voltage sensor, so the controller does not control the output of the second drive system. Limits the driving torque of the motor.

Therefore, a problem arises in that the balance of the overall torque is disturbed and the output of the vehicle is lowered.

In addition, when the voltage monitored by each drive system exceeds the set reference voltage due to an error of the voltage sensor, it is determined that the overvoltage supply failure causes the main relay to be shut off, thereby causing a problem in that the vehicle is shut down.

The present invention has been proposed to solve the above problems, an object of the present invention is to control the speed and torque of the motor to the average value of the voltage monitored in each drive system constituting the multi-drive system to provide stability to the operation. will be.

In order to achieve the above object, according to an embodiment of the present invention, a fuel cell stack that is a power source; A super cap that assists the output of the fuel cell stack and charges regenerative braking energy; At least one inverter for converting the DC voltage supplied from the fuel cell stack and the supercap into a three-phase voltage; At least one voltage sensor for detecting a voltage supplied to at least one inverter in the fuel cell stack and the supercap; Provided is a control device for a vehicle having a multi-drive system including a controller which applies an average value of voltages detected by the one or more voltage sensors to generate a voltage and torque control command for driving a motor.

The controller may generate a voltage and torque control command for driving the motor by applying the voltage value detected by the voltage sensor when the average voltage detected by the voltage sensor is lower than the set minimum voltage.

The controller may generate a voltage and torque control command for driving the motor by applying the voltage value detected by the voltage sensor when the average voltage detected by the voltage sensor is higher than the set maximum voltage.

In addition, according to another embodiment of the present invention, the step of calculating the voltage average value by detecting a voltage supplied to at least one inverter with a voltage sensor; Comparing the average voltage detected by the voltage sensor with a set minimum maximum reference voltage; When the voltage average value is higher than the minimum reference voltage and lower than the maximum reference voltage, a control method of a vehicle having a multi-drive system including generating a torque control command by applying the average voltage and controlling the switching by an inverter is provided.

When the voltage average value detected by the voltage sensor is lower than the set minimum reference voltage or higher than the maximum reference voltage, the voltage detected by the voltage sensor may be applied to the generation of the torque control command.

As such, the present invention can provide a stable and reliable operation by eliminating the output limitation caused by the error of the voltage sensor in the vehicle to which the multi-drive system is applied.

1 is a view schematically showing a control apparatus of a vehicle having a multi-drive system according to an embodiment of the present invention.
2 is a flow chart showing a control procedure of a vehicle having a multi-drive system according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art to which the present invention pertains can easily carry out the embodiments.

The present invention can be embodied in various different forms, and thus the present invention is not limited to the embodiments described herein.

1 is a view schematically showing a control apparatus of a vehicle having a multi-drive system according to an embodiment of the present invention.

Referring to FIG. 1, the present invention provides a fuel cell stack 10 as a main power source, a supercap 20 as a secondary power source, a plurality of inverters 31 to 33, a plurality of voltage sensors 41 to 43, and a plurality of motors ( 51-53), the PCD 60, the GDU 70, and the controller 100.

The fuel cell stack 10 may be composed of one or more than one according to its capacity, and through the chemical reaction of hydrogen supplied to the anode of the unit cell and oxygen supplied to the cathode according to the operation of the peripheral device (BOP). Generate electricity.

The supercap 20 is connected in parallel to the power line 12 to assist the output power of the fuel cell stack 10 and charge regenerative braking energy to provide efficient use of the fuel cell.

The inverters 31 to 33 are configured in plural and connected to the power line 12, and the DC voltages output from the fuel cell stack 10 and the supercap 20 according to the control signal of the controller 100 through high speed switching. It converts into a three-phase voltage and supplies it to the corresponding motor 51-53 as a drive voltage.

The voltage sensors 41-43 detect the voltage output from the fuel cell stack 10 and the supercap 20 and supplied to the inverters 31-33 through the power line 12, and display information on the controller 100. To provide.

The motors 51-53 are operated at the point where the driving torque and the driving time are adjusted according to the control of the corresponding inverters 31-33 to maximize the total efficiency, and the output torque of each motor 51-53 is PCD. (Power Coupling Device: 60) is converted into a single output, and is transmitted to the driving wheel via the GDU 70 so that the driving can be made.

The controller 100 generates a torque control command by applying a voltage average value when the controller 100 is included in the range of the maximum voltage and the minimum voltage set by averaging the inverter supply voltages detected by the voltage sensors 41-43. 53) is executed.

In a vehicle having a multi-drive system according to the present invention including the functions as described above, the operation of supplying a voltage to the motor of each drive system is performed as follows.

The controller 100 is output from the fuel cell stack 10 and the supercap 20 in a state in which a vehicle having a multi-drive system is waiting for driving or driving. Each inverter 31-33 is output through the power line 12. The voltage supplied thereto is detected through the corresponding voltage sensors 41-43 (S101).

The controller 100 calculates an average value Vol_Avg of the voltages supplied to the respective inverters 31-33 (S102).

Thereafter, the controller 100 determines whether the calculated voltage average value Vol_Avg is lower than the set system minimum voltage Vol_Min or the calculated voltage average value Vol_Avg is higher than the set system maximum voltage Vol_Max (S103). .

If the voltage average value Vol_Avg calculated in S103 is higher than the set system minimum voltage Vol_Min or lower than the maximum voltage Vol_Max, the controller 100 applies the voltage average value Vol_Avg to the first to third motors. After generating the voltage and torque control commands for driving 51-53, the generated voltage and torque control commands are output to the inverters 31-33 constituting each drive system (S105).

Accordingly, the inverters 31 to 33 perform switching according to the voltage and torque control commands to convert the DC voltage supplied from the fuel cell stack 10 into a three-phase voltage and supply the motor 51-53 as a driving voltage. The output of the motor 51-53 does not generate an output limitation, thereby providing stable and reliable driving (S106).

In addition, when the voltage average value Vol_Avg calculated in S103 is lower than the set system minimum voltage Vol_Min or the calculated voltage average value Vol_Avg is higher than the set system maximum voltage Vol_Max, the controller 300 is a voltage sensor. The voltage value detected in (41-43) is applied as it is (S104).

Thereafter, the controller 100 generates voltage and torque control commands for driving the first to third motors 51 to 53 by applying the voltage values detected by the voltage sensors 41 to 43, and then configures each drive system. The generated voltage and torque control commands are output to the inverters 31 to 33 (S105).

Accordingly, the inverters 31 to 33 perform switching according to the voltage and torque control commands to convert the DC voltage supplied from the fuel cell stack 10 into a three-phase voltage and supply the motor 51-53 as a driving voltage. The output of the motor 51-53 does not generate an output limitation, thereby providing stable and reliable driving (S106).

As described above, the present invention can prevent an overvoltage fault determination that can be generated by reading an output limit lower than the actual voltage of the fuel cell stack and generating a reading due to an error of a voltage sensor in a vehicle having a multi-drive system. Stability and reliability are provided.

While the present invention has been particularly shown and described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, , Additions, deletions, and so on, other embodiments may be easily suggested, but this is also included in the spirit of the present invention.

10: fuel cell stack 20: supercap
31-33: Inverter 41-43: Voltage Sensor
51-53: Motor

Claims (5)

In a multi-drive system having a plurality of drive systems,
Fuel cell stack as a power source;
A super cap that assists the output of the fuel cell stack and charges regenerative braking energy;
At least one inverter for converting the DC voltage supplied from the fuel cell stack and the supercap into a three-phase voltage;
At least one voltage sensor for detecting a voltage supplied to at least one inverter in the fuel cell stack and the supercap;
A controller for generating a voltage and torque control command for driving a motor by applying an average value of voltages detected by the one or more voltage sensors;
Control device of a vehicle having a multi-drive system comprising a. The method of claim 1,
The controller generates a voltage and torque control command for driving the motor by applying the voltage value detected by the voltage sensor when the average voltage detected by the voltage sensor is lower than the set minimum voltage. Control unit. The method of claim 1,
The controller generates a voltage and torque control command for driving the motor by applying the voltage value detected by the voltage sensor when the average voltage detected by the voltage sensor is higher than the set maximum voltage. Control unit. In the control method of a vehicle having a multi-drive system,
Calculating a voltage average value by detecting a voltage supplied to at least one inverter with a voltage sensor;
Comparing the average voltage detected by the voltage sensor with a set minimum maximum reference voltage;
When the average voltage is higher than the minimum reference voltage and lower than the maximum reference voltage, generating a torque control command by applying the average voltage to control the inverter by switching the inverter;
Control method of a vehicle having a multi-drive system comprising a. The method of claim 4, wherein
And controlling the voltage detected by the voltage sensor to generate a torque control command when the voltage average value detected by the voltage sensor is lower than the set minimum reference voltage or higher than the maximum reference voltage.

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