KR-102963389-B1 - MOTOR DRIVING APPARATUS

KR102963389B1KR 102963389 B1KR102963389 B1KR 102963389B1KR-102963389-B1

Abstract

A motor driving device is disclosed for driving a motor having a plurality of windings each corresponding to a plurality of phases. The motor driving device comprises: a first inverter including a plurality of first switching elements and connected to a first terminal of each of the plurality of windings; a second inverter including a plurality of second switching elements and connected to a second terminal of each of the plurality of windings; and a controller that generates a limited pole voltage command for space vector pulse width modulation based on a preset voltage command of the motor, and distributes the limited pole voltage command to generate a first pole voltage command for switching the first switching element and a second pole voltage command for switching the second switching element.

Inventors

이용재
유정모
정장윤

Assignees

현대자동차주식회사
기아 주식회사

Dates

Publication Date: 20260508
Application Date: 20210810

Claims (11)

In a motor driving device for driving a motor having a plurality of windings corresponding to a plurality of phases, A first inverter comprising a plurality of first switching elements and connected to the first terminal of each of the plurality of windings; A second inverter comprising a plurality of second switching elements and connected to the second terminal of each of the plurality of windings; and A controller that generates a limited pole voltage command for space vector pulse width modulation based on a preset voltage command of the motor, and distributes the limited pole voltage command to generate a first pole voltage command for switching the first switching element and a second pole voltage command for switching the second switching element; Includes, The limit of the above restricted pole voltage command is '( /2)*Vdc-amp(V n * )' and, The lower limit of the above limited pole voltage command is '-{( A motor driving device characterized by being '/2)*Vdc-amp(V n * )}' (wherein 'Vdc' is the DC link voltage of the first inverter and the second inverter, 'V n * ' is the zero-phase component of the voltage command of the motor, and amp is an operator representing the magnitude).
In claim 1, the controller is, A motor driving device characterized by generating a phase voltage command for each phase of the motor by performing a reverse rotation conversion that leads or lags the rotation angle of the motor by 30 degrees with respect to the voltage command of the motor in order to generate the above-mentioned limited pole voltage command.
In claim 2, the controller is, A motor driving device characterized by generating an offset voltage corresponding to the average of the maximum and minimum values among the above-mentioned phase voltage commands, and generating the above-mentioned limited pole voltage command by subtracting the above-mentioned offset voltage from each of the above-mentioned phase voltage commands.
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In claim 3, the controller is, 1/ to the above limited pole voltage command Winning, 1/1 times P of the zero-phase component of the voltage command of the above motor The first pole voltage command is generated by adding to this multiplied limited pole voltage command, and 1/2 times P of the zero-phase component of the voltage command of the above motor A motor driving device characterized by generating the second pole voltage command by subtracting from the multiplied limited pole voltage command (wherein P1 + P2 = 1).
In claim 6, A motor drive device characterized in that the above P1 and P2 have different values.
In claim 6, the controller is, When a reverse rotation conversion leading the rotation angle of the above motor by 30 degrees is performed, The phase a, phase b, and phase c components of the first pole voltage command are determined to correspond, respectively, to the phase a, phase b, and phase c components of the limited pole voltage command, and A motor driving device characterized by determining that the phase a, phase b, and phase c components of the second pole voltage command correspond to the phase b, phase c, and phase a components of the limited pole voltage command, respectively.
In claim 6, the controller is, When a reverse rotation conversion leading the rotation angle of the above motor by 30 degrees is performed, 1/ to the a, b, and c components of the above limited pole voltage command The a-phase, b-phase, and c-phase components of the first pole voltage command are generated respectively by adding P 1 times the zero-phase component of the voltage command of the motor to the value multiplied by the above, and 1/ to the b-phase, c-phase, and a-phase components of the above limited pole voltage command A motor driving device characterized by generating the a-phase, b-phase, and c-phase components of the second pole voltage command by subtracting twice the zero-phase component of the motor voltage command from the value multiplied by the value.
In claim 6, the controller is, When a reverse rotation conversion lagging 30 degrees behind the rotation angle of the above motor is performed, The phase a, phase b, and phase c components of the first pole voltage command correspond to the phase a, phase b, and phase c components of the limited pole voltage command, respectively. A motor driving device characterized in that the phase a, phase b, and phase c components of the second pole voltage command correspond respectively to the phase c, phase a, and phase b components of the limited pole voltage command.
In claim 6, the controller is, When a reverse rotation conversion lagging 30 degrees behind the rotation angle of the above motor is performed, 1/ to the a, b, and c components of the above limited pole voltage command The a-phase, b-phase, and c-phase components of the first pole voltage command are generated respectively by adding P 1 times the zero-phase component of the voltage command of the motor to the value multiplied by the above, and 1/ to the c-phase, a-phase, and b-phase components of the above limited pole voltage command A motor driving device characterized by generating the a-phase, b-phase, and c-phase components of the second pole voltage command by subtracting twice the zero-phase component of the motor voltage command from the value multiplied by the value.

Description

Motor Driving Apparatus The present invention relates to a motor driving device, and more specifically, to an open-end winding type motor driving device in which an inverter is connected to each end of the motor winding. Generally, one end of each phase winding included in the motor is connected to a single inverter, and the other ends are connected to each other to form a Y-connection. When driving the motor, the switching element in the inverter is turned on/off by pulse width modulation control, and torque is generated by applying line voltage to the windings of the Y-connected motor to generate alternating current. Since the fuel efficiency (or electric efficiency) of eco-friendly vehicles, such as electric vehicles that utilize torque generated by such motors as power, is determined by the power conversion efficiency between the inverter and the motor, it is important to maximize the power conversion efficiency of the inverter and the efficiency of the motor to improve fuel efficiency. The efficiency of an inverter-motor system is primarily determined by the voltage utilization rate of the inverter; if the vehicle's operating point, determined by the relationship between motor speed and torque, is formed in a range of high voltage utilization, the vehicle's fuel efficiency can be improved. However, increasing the number of windings to boost maximum torque causes the high-voltage utilization region to move further away from the low-torque region, which is the vehicle's primary operating point, potentially leading to poor fuel efficiency. Furthermore, designing the motor to include the primary operating point within the high-voltage utilization region for the sake of fuel efficiency may result in limitations on the motor's maximum torque, which can lead to reduced acceleration performance. To solve this problem, an Open End Winding (OEW) motor driving technique has been proposed in the field of technology, in which two inverters are driven by connecting an inverter to each end of the motor winding instead of short-circuiting one end of the motor winding through a Y connection. This open-end winding motor driving technique has the advantage of being able to increase phase voltage to improve voltage utilization and enable high output compared to the method of driving a conventional Y-connected motor. However, in open-end winding motor driving techniques, when a common DC power source is applied to inverters connected to each end of the motor winding, the zero-phase component voltage cannot be controlled to be zero on average over the inverter switching period, which can generate common-mode current. This common-mode current flows through the motor windings and acts as losses such as copper loss and iron loss, which reduce motor efficiency and, in severe cases, can cause the motor system to burn out. The matters described above as background technology are intended only to enhance understanding of the background of the present invention and should not be construed as an acknowledgment that they constitute prior art already known to those skilled in the art. FIG. 1 is a circuit diagram of a motor driving device according to one embodiment of the present invention. FIG. 2 is a block diagram illustrating in detail a conventional controller for controlling a motor using an open-end winding method. Figure 3 is a voltage vector diagram to explain the motor control technique applied in a conventional controller shown in Figure 2. Figure 4 is a waveform diagram showing the voltage output of each inverter generated during motor control by the conventional controller shown in Figure 2. FIG. 5 is a block diagram illustrating the spatial vector modulation unit within a conventional controller shown in FIG. 2 in more detail. FIG. 6 is a block diagram showing in detail a controller applied to a motor driving device according to one embodiment of the present invention. FIG. 7 is a block diagram illustrating in more detail a space vector modulation unit within a controller applied to a motor driving device according to an embodiment of the present invention shown in FIG. 6. FIG. 8 is a waveform diagram showing the voltage output of each inverter generated by the control of a motor driving device according to an embodiment of the present invention shown in FIG. 6. FIG. 9 is a block diagram illustrating in detail a controller applied to a motor driving device according to another embodiment of the present invention. FIG. 10 is a voltage vector diagram for explaining an example in which the phase voltage command of the first inverter is converted to lead the rotation angle of the motor by 30 degrees and the phase voltage command of the second inverter is converted to lead the rotation angle of the motor by 150 degrees in the embodiment of the present invention shown in FIG. 9. FIG. 11 is a voltage vector diagram for explaining an example in which the phase voltage command of the first inverter is converted to 30 degrees behin