KR20180065518A - A motor system, a vehicle including the same and a method for controlling the same - Google Patents

Abstract

The present invention provides a motor system, a vehicle, and a controlling method of the motor system and the vehicle, which prevent a user such as a driver or a passenger from recognizing noise caused by an inverter switching of a motor. The motor system comprises: a motor driving part operating or stopping at least one switching element according to a switching frequency; the motor applying current according to an operation of the at least one switching element, and arranging a coil which generates a magnetic field according to the applied current and a rotor which rotates at a rotation frequency corresponding to the switching frequency by the magnetic field; and a control part controlling the switching frequency based on the rotation frequency of the motor, and controlling the switching frequency so that the noise caused by the rotation frequency of the motor exceeds a reference frequency.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a motor system, a vehicle, a motor system,

A motor system, a vehicle, the motor system, and a control method of the vehicle.

A vehicle means a device capable of moving from one position to another while traveling on a road or a track. The vehicle may include, for example, a two-wheeled automobile such as a three-wheeled or four-wheeled automobile or a motorcycle, a train traveling on a construction machine, a bicycle, or a rail disposed on the railway.

The vehicle can run on roads or the like by rotating one or more wheels installed on the vehicle body. Power for wheel rotation can be obtained through various methods. For example, a vehicle can be a vehicle that converts the thermal energy obtained by burning fossil fuels such as gasoline or diesel into mechanical energy to obtain power for wheel rotation, or, for another example, The power for turning the wheel may be obtained. A vehicle that obtains power by using electric energy is called an electric vehicle.

Electric vehicles include a general electric vehicle (EV) that acquires power using only electric energy, and a hybrid electric vehicle that acquires power using at least one of energy and electric energy resulting from combustion of fossil fuel (Hybrid Electric Vehicle), a plug-in hybrid electric vehicle (PHEV) that uses both combustion energy and electric energy but can receive and store electric energy from the outside, And a fuel cell electric vehicle (FCEV) that acquires power by an electrochemical action of a fuel cell.

A motor system, a vehicle, a motor system, and a control method of the vehicle are provided that prevent a user such as a driver or a passenger from recognizing a noise caused by inverter switching of a motor.

A motor system, a vehicle, a motor system, and a control method for the vehicle that can minimize the noise generated in the motor system while minimizing the complexity and the efficiency deterioration of the motor system.

To solve the above-described problems, a motor system, a vehicle, the motor system, and a control method of the vehicle are provided.

The motor system includes a motor driver for operating at least one switching element or stopping operation according to a switching frequency, a coil for generating a magnetic field according to an applied current according to the operation of the at least one switching element, A motor provided with a motor rotatable at a rotation frequency corresponding to the switching frequency by the magnetic field, and a control unit for controlling the switching frequency based on the rotation frequency of the motor, wherein the switching frequency and a frequency May control the switching frequency to be equal to or greater than the reference frequency.

The control unit may determine the switching frequency in proportion to a sum or difference of the reference frequency and the rotation frequency of the motor.

Wherein a frequency of a noise generated in the motor driving unit and the motor is defined in proportion to a sum or a difference of the switching frequency and the rotation frequency of the motor and the control unit controls the frequency of the noise generated in the motor driving unit and the motor The switching frequency can be determined based on the switching frequency.

Wherein the noise generated according to the switching frequency and the rotation frequency of the motor includes a first noise and a second noise having a relatively lower frequency than the first noise, wherein the frequency of the first noise and the frequency of the second noise are Can be symmetrical to each other based on the switching frequency.

The control unit may determine the switching frequency in proportion to a sum of a frequency of the first noise and a frequency of the second noise.

The control unit may control the switching frequency such that a frequency of the noise for the second noise exceeds a reference frequency.

The reference frequency may be defined based on the frequency of the audio frequency band.

The frequency of the second noise may comprise the upper frequency of the audible frequency band.

The reference frequency may be defined to be equal to or close to the upper limit frequency of the audio frequency band.

The reference frequency may be defined by further utilizing the vibration characteristics of at least one of the motor driving unit and the motor.

The vehicle includes a motor driver for operating at least one switching element or stopping operation according to a switching frequency, a coil for generating a magnetic field according to an applied current according to an operation of the at least one switching element, A motor provided with a motor rotatable by a magnetic field at a rotation frequency corresponding to the switching frequency; and a control unit for controlling the switching frequency based on the rotation frequency of the motor, wherein the switching frequency and the frequency of the noise due to the rotation frequency of the motor And a control unit for controlling the switching frequency to be equal to or greater than a reference frequency.

The control unit may determine the switching frequency in proportion to a sum or difference of the reference frequency and the rotation frequency of the motor.

The vehicle may further include at least one of a traveling speed obtaining unit for determining a running speed of the vehicle and a noise measuring unit for measuring noise generated in the motor and the motor driving unit.

The control unit may determine the reference frequency using at least one of the running speed of the vehicle and the noise.

The vehicle may further include an engine for acquiring power for driving and an engine motion sensing unit for determining whether the engine is operating.

The vehicle can determine the reference frequency depending on whether the engine is operating or not.

A control method of a motor system includes a step of determining a reference frequency, a step in which a motor driving unit electrically connected to the motor operates based on a switching frequency, the motor starts driving, and the motor is rotated at a rotation frequency corresponding to the switching frequency And controlling the switching frequency based on the rotational frequency of the motor such that the switching frequency and the frequency of the noise due to the rotational frequency of the motor are equal to or greater than a reference frequency can do.

A method of controlling a vehicle, comprising the steps of: determining a reference frequency; operating a motor driving unit electrically connected to the motor based on a switching frequency; starting the driving of the motor and rotating at a rotational frequency corresponding to the switching frequency And controlling the switching frequency based on the rotational frequency of the motor, wherein the switching frequency and the frequency of the noise due to the rotational frequency of the motor are equal to or greater than a reference frequency .

The step of determining the reference frequency may include determining a running speed of the vehicle, and measuring noise generated in the motor and the motor driving unit. The determining of the reference frequency may further include determining the reference frequency using at least one of the running speed of the vehicle and the noise.

The determining of the reference frequency may further include determining whether the engine is driven, and determining the reference frequency according to whether the engine is driven.

According to the motor system, the vehicle, the motor system, and the control method of the vehicle described above, the user such as the driver or the passenger can not recognize the noise caused by the inverter switching of the motor, The quietness can be improved.

According to the motor system, the vehicle, the motor system and the control method of the vehicle described above, the noise generated in the motor system becomes unhealthy while minimizing the complexity and the drop in efficiency of the motor system, The satisfaction level can be improved.

1 is a block diagram of an embodiment of a vehicle.
2 is a block diagram of one embodiment of a motor system.
3 is a diagram showing an example of noise generated in the motor system.
FIG. 4 is a view schematically showing noise generated in the motor system. FIG.
5 is a view briefly showing an example of noise generated in the motor system when it is controlled according to the first embodiment.
6 is a diagram illustrating an example of noise generated in the motor system when the inverter switching frequency up method is used.
7 is a view for comparing the noise generated when the inverter switching frequency up method is used and the noise generated when the inverter is controlled according to the first embodiment.
8 is a view showing an example of noise generated in the motor system when it is controlled according to the second embodiment.
9 is a diagram showing an example of noise generated in the motor system when it is controlled according to the third embodiment.
10 is a block diagram of another embodiment of a vehicle.
11 is a flowchart of an embodiment of a method of controlling a motor system.

In the following specification, like reference numerals refer to like elements throughout the specification unless otherwise specified. As used herein, the term " part " may be embodied in software or hardware, depending on the designer's choice, and may be embodied in one or more parts, As shown in FIG.

When a part is connected to another part throughout the specification, it may mean a physical connection, or may be electrically connected, depending on which part and the other part.

Also, when a part includes another part, it does not exclude another part other than the other part unless specifically stated otherwise, and it may include another part depending on the designer's choice .

The terms such as the first and second terms are used to distinguish one part from another part and do not mean that they are provided sequentially or sequentially unless otherwise specified.

Furthermore, the singular < RTI ID = 0.0 > expressions < / RTI > may include a plurality of expressions unless the context clearly dictates otherwise.

One embodiment of a vehicle equipped with a motor system and a motor system will now be described with reference to FIGS. 1 to 10. FIG.

1 is a block diagram of an embodiment of a vehicle.

The vehicle 1 may be a general automobile capable of running using the combustion energy of the fuel, or may be an electric vehicle capable of running using electric energy. In this case, the electric vehicle may be a conventional electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a hydrogen fuel cell vehicle.

1, the vehicle 1 may include a motor system 100 and a battery 190 for supplying power to the motor system 100. [

The motor system 100 and the battery 190 are electrically connected through at least one conductor or metal circuit. Both the motor system 100 and the battery 190 may be installed in a section of the interior of the vehicle 1. [ For example, the motor system 100 may be installed in the engine room of the vehicle 1, or between the engine room and the dashboard, and the battery 190 may be installed in the engine room of the vehicle 1, Or a space between the rear seat and the rear loading space of the vehicle 1 or a rear loading space of the vehicle 1. [

The motor system 100 may include a motor 110, a motor driver 130, and a controller 150.

The motor 110 can convert electrical energy into mechanical energy, i.e., rotational energy, to obtain power required for various operations of the vehicle 1. [

The motor 110 may include a direct current motor, an alternating current motor, a direct current brushless motor (BLDC motor), or a linear induction motor, depending on the embodiment, Which may include various types of motors.

According to one embodiment, the motor 110 may include a stator 111, a coil 112, and a rotor 113.

The stator 111 is formed around the rotor 113. In one embodiment, the stator 111 may include a predetermined formed frame, for example, an annular frame, and at least one protrusion fixedly and protruding inside the annular frame. According to one embodiment, the stator 111 may include six protrusions, in which case six protrusions may be provided symmetrically. Accordingly, each of the projections can face the other projections.

2 is a block diagram of one embodiment of a motor system.

The coil 112 is wound around at least one protrusion of the stator 111 and can generate a magnetic field corresponding to the current according to the application of the electric current. The coil 112 may include a plurality of coils 112a, 112b, and 112c as shown in FIG. In this case, the coil wound on one of the protrusions can be extended and wound on the protrusion opposed to one of the protrusions. For example, when the stator 111 includes six protrusions, three coils may be provided, and each of the coils may be wound on two protrusions opposed to each other and installed in the stator 111.

The coil 112 is electrically connected to the motor driving unit 130 and the circuit or the wires 137 to 139. The alternating current flows or the alternating current flows in the coil 112 according to the operation of the motor driving unit 130 Thereby generating a magnetic field at a specific position inside the annular frame.

The rotor 113 can rotate around a predetermined rotation axis inside the annular frame according to the magnetic field generated by the coil 112. [ The rotor 113 can be implemented using a permanent magnet or the like. The rotational force of the rotor 113 is transmitted to a part, such as a wheel or a hydraulic pump, which requires power through various parts such as gears and shafts.

The rotor 113 can rotate at a predetermined rotation frequency. The rotational frequency of the rotor 113 may correspond to the switching frequency of each of the switch elements 131 to 136 of the motor driving unit 130. [ The switching frequency means the number of times the ON / OFF operation of each of the switch elements 131 to 136 is repeated for a unit time. Each of the switch elements 131 to 136 repeats the operation start and the operation stop according to the switching frequency.

The motor driving unit 130 receives an electric signal of a predetermined voltage from the battery 190 and transmits the supplied electric current to the coil 112 of the motor 110. According to one embodiment, the motor driver 130 may be implemented using an inverter.

Referring to FIG. 2, the motor driving unit 130 may include at least one switching element 131 to 136. The switch elements 131 to 136 may selectively or not transmit the current inputted from the battery 190 to the coils 112a to 112c corresponding to the respective switch elements 131 to 136. [ According to the embodiment, the motor driving unit 130 may include one or two or more switch elements 131 to 136. In this case, the number of switch elements 131 to 136 corresponds to the number of the coils 112a to 112c on the motor 110, that is, the motor.

The switch elements 131 to 136 may be implemented, for example, by including a metal oxide semiconductor field effect transistor (MOSFET).

According to one embodiment, the switch elements 131 to 136 may be insulated gate bipolar transistors (IGBTs).

The two switch elements 131 and 132, 133 and 134, 135 and 136 of the switch elements 131 to 136 are provided to correspond to each other. A voltage is applied to any one of the switch elements 131, 132, 133, 134, 135, 136 corresponding to each other, and the other switch element 132, 134, It is connected to ground. The current is transmitted to the motor driving unit 130 through one of the switching elements 131, 133 and 135 and the current passing through the coils 112a to 112c is discharged to the outside of the motor driving unit 130. [

A current flows in a predetermined direction in at least two of the first coil 112a, the second coil 112b and the third coil 112bc in accordance with the operation of each of the switch elements 131 to 136. [ In this case, depending on which of the switching elements 131 to 136 has been operated, a current in a specific direction flows to a specific one of the plurality of coils 112a, 112b, and 112c.

For example, when the first switch element 131 and the fourth switch element 134 operate, the alternating current is sequentially supplied to the first coil 112a and the second coil 112b through the circuit or the wire 137 And is transmitted to the fourth switch element 134 through the circuit or the wire 138.

Similarly, when the first switch element 131 and the sixth switch element 136 operate, the current flows sequentially through the first coil 112a and the third coil 112c, and flows through the third switch element 133 and the third switch element 112c, When the six switch element 136 operates, the current flows sequentially through the second coil 112b and the third coil 112c.

When the second switch element 132 and the third switch element 133 operate, the current flows sequentially through the second coil 112b and the first coil 112a, and the fourth switch element 134 When the fifth switch element 135 operates, the current flows sequentially through the third coil 112c and the second coil 112b. When the second switch element 132 and the fifth switch element 135 operate, the current flows sequentially through the third coil 112c and the first coil 112a.

When alternating current in a predetermined direction flows through each of the coils 112a to 112c, a magnetic field corresponding to the magnitude and direction of the alternating current is sequentially generated in the internal space of the motor 110, do.

Each of the switch elements 131 to 136 is repeatedly operated and stopped (ON / OFF) at a predetermined switching frequency for the operation of the motor 110. The repetition of operation and interruption of the switch elements 131-136 may cause current and / or voltage ripple in the power supply line to correspond to the switching frequency. The ripple of current and / or voltage may cause high frequency vibration and noise of motor 110, motor drive 130 and associated components.

The control unit 150 is provided to control the overall operation of the motor system 100. According to the embodiment, the control unit 150 may control the overall operation of the vehicle 1. [

The control unit 150 may be implemented using a processor using at least one semiconductor chip and related components. The processor may be, for example, a central processing unit (CPU) or a micro control unit (MCU). In the case of the vehicle 1, the processor may be a Vehicle Control Unit (VCU). Not only these but also various kinds of processors separately provided for performing various calculations and processes are available to the control unit 150 described above.

According to the embodiment, the control unit 150 controls the switching elements 131 to 136 of the motor driving unit 130 to start or stop the operation in a predetermined pattern, ) Can be adjusted.

The control unit 150 may control the switching frequency of each of the switching devices 131 to 136 based on the rotational frequency of the rotor 113 of the motor 110. [ In this case, the control unit 150 may control the switching frequency of each of the switching elements 131 to 136 such that the noise according to the rotational frequency of the rotor 113 exceeds the reference frequency.

Here, the reference frequency may be determined based on the audible frequency band. That is, the reference frequency may be defined to be equal to an upper limit of the audible frequency band. The audible frequency band means the frequency range of sound waves that can be heard by humans. The audio frequency band may include a frequency band of approximately 16 Hz to 20 kHz.

Further, the reference frequency may be defined to approximate the upper limit frequency of the audible frequency band. In this case, the reference frequency may be defined as a frequency that is relatively larger than the upper limit frequency of the audible frequency band, or may be defined as a frequency that is relatively smaller than the upper limit frequency of the audible frequency band.

The reference frequency may be constant or may vary depending on the embodiment. For example, the reference frequency may be variable according to the driving conditions of the various vehicles 1. [

The reference frequency may be predefined by the designer or defined by the user. In this case, the reference frequency may be temporarily or non-temporarily stored in a separate storage device (not shown), and may be provided to the control unit 150 upon a call of the control unit 150.

Further, the reference frequency may be determined by the control unit 150. [ According to one embodiment, the control unit 150 can determine the reference frequency using various information, for example, whether or not the engine 180 is operated, whether noise is generated, and the like. In addition, the control unit 150 may determine the reference frequency using the vibration characteristics of various components in the motor system 100. [ Here, various components in the motor system 100 are connected to the stator 111 of the motor 110, the coil 112, the rotor 113, the switching elements 131 to 131 of the motor driving unit 130, 136, conductors or circuits 137-139, and the like.

The specific operation of the control unit 150 will be described later.

The storage battery 190 is provided so as to store electric energy. The battery 190 may be a lithium-ion battery such as a lithium-titanium battery, a lithium-polymer battery, a lithium-ion battery or a lithium-air battery, a lead storage battery, a nickel-cadmium storage battery, a sodium- And the like.

The battery 190 is electrically connected to the motor driving unit 130 and supplies the electric energy required for the motor driving unit 130 under the control of the control unit 150 so that the motor 110 is operated. The battery 190 is provided to be directly or indirectly connected to the switching elements 131 to 136 of the motor driving unit 130 via a wire or a circuit provided in the vehicle 1. [

The vehicle 1 may further include an engine 180, depending on the embodiment. As described above, the engine 180 converts the combustion energy of the fossil fuel into mechanical energy, and acquires the power necessary for running the vehicle 1. [ In the case of a conventional electric vehicle, the engine 180 may be omitted.

Hereinafter, the specific operation of the control unit 150 will be described with reference to FIGS. 3 to 9. FIG.

The magnitude F (t) of the noise according to the time t may be given by the following equation (1).

Here, p and q are 0 or arbitrary integers larger than 0,? _S is the switching angular velocity of the motor driving unit 130, and? _M is the rotational angular velocity of the rotor 113 of the motor 110. [ Also, A (p, q, ω _s , ω _m ) and B (p, q, ω _s , ω _m ) are functions that can be given according to various external conditions. Here, various external conditions may include a current, a voltage, and a noise source applied to the motor system 100 when the vehicle 1 travels, for example, a vibration characteristic of a rotor or the like. The value of the function A (p, q, ω _s , ω _m ) and the function B (p, q, ω _s , ω _m ) can increase substantially as the value of p or q decreases.

Since the magnitude of the overall noise F (t) is a sum of a plurality of sinusoidal functions, the frequency fn of the overall noise can be calculated by the following equation (2) It is definable.

Here, fs is the switching frequency of the motor driver 130, and fm is the rotational frequency of the motor 110. [ a and b are integers equal to or greater than zero (a? 0, b? 0).

In other words, in the motor system 100, noise of a frequency fn given by a sum of an integral multiple of the switching frequency fs of the motor drive unit 130 and an integer multiple of the rotation frequency fm of the motor 110 is generated do. The motor system 100 may also generate noise of a given frequency fn by an integer multiple of the switching frequency fs and an integer multiple of the rotation frequency fm of the motor 110. [

In this case, since a or b may be 0, the frequency fn of the overall noise may be equal to an integral multiple of the switching frequency fs of the motor driving unit 130, or the rotation frequency fm ). ≪ / RTI > Therefore, in the motor system 100, the noise fn is generated as shown in FIG.

3 is a view showing an example of noise generated in a conventional motor system. More specifically, FIG. 3 shows a spectrum of the noise measured around the battery when the electric vehicle accelerates during the first period to the fifth period (P1 to P5) and during the regenerative braking in the sixth period (P6). Each of the switching elements 131 to 136 of the motor driving unit 130 was controlled to have a switching frequency that varies between 3 kHz and 5 kHz according to the speed and torque of the motor.

3, when the motor drive unit 130 of the motor system 100 of the vehicle 1 is switched according to the predetermined switching frequency fs, the switching frequency fs and the rotation of the motor 110 A plurality of noises of a frequency fn different from each other depending on the frequency fm can be generated. In this case, the frequencies fn of the generated noises may be non-continuous with each other.

As described in Equation (2), the frequency fn of the noise generated in the motor system 100 may be the same or approximate to an integral multiple of the switching frequency fs. The frequency fn of the noise may be equal to or approximate to the sum of an integral multiple of the switching frequency fs and an integral multiple of the rotation frequency fm of the motor 110 or an integral multiple of the switching frequency fs And the rotation frequency fm of the motor 110. In this case,

For example, during the third period P3 during which the vehicle 1 is accelerated, the frequency fn of the motor system 100 is multiplied by one times the switching frequency fs of the motor driving unit 130, Of the motor 110 and three times the rotational frequency fm of the motor 110 and three times the rotational frequency fm of the motor 110 at the frequency fn equal to one times the switching frequency fs of the motor driving unit 130, Noise may be generated. The noise having the frequency fm twice as high as the switching frequency fs of the motor driving unit 130 during the third period P3 and the noise having the frequency twice the switching frequency fs of the motor driving unit 130, The sum of the noise having the sum frequency fm 6 times the rotational frequency fm of the motor 110 and the noise having the frequency twice the switching frequency fs of the motor driving unit 130 and the rotational frequency fm of the motor 110 The noise having the frequency fm of the difference of the frequency fm may also be generated.

Similarly, in the fourth period P4, noise having a frequency fn of fs + 3 * 8fm, noise of 2 * fs + 6 * 8fm, and noise of 3 * fs + 9 * 8fm may occur. In the fifth period P5, the noise of frequency fn is fs + 3 * 8fm, the noise of 2 * fs + 6 * 8fm, the noise of 3 * fs + 3 * 8fm, * 8fm noise and 4 * fs ± 6 * 8fm noise may occur. The noise fs + 3 * 8fm, the noise fs + 9 * 8fm, and the noise fs + 2 * fs + 6 * 8fm Noise of 2 * fs + 12 * 8fm, noise of 3 * fs + 3 * 8fm, and noise of 3 * fs + 9 * 8fm may occur.

FIG. 4 is a view schematically showing noise generated in the motor system. FIG. In FIG. 4, f10 denotes a set switching frequency, that is, a first switching frequency, and n11 to n17 denote the noise generated in the motor system 100 Noise.

4, when the switching frequency fs is given as the first switching frequency f10, the rotation frequency of the motor 110 corresponding to the first switching frequency f10 and the first switching frequency f10 fm), noise (n11 to n17), which are different from each other, is generated in the motor system 100. The frequency of each noise n11 to n17 can be changed in accordance with the change of at least one of the switching frequency fs and the rotation frequency fm of the motor 110,

As described above, in the motor system 100, the noise n13 corresponding to the first switching frequency f10 of the motor driving unit 130 may occur. The generated noise n13 has the frequency equal to the first switching frequency f10 or an integral multiple of the first switching frequency f10. For example, the frequency of the third noise f13 may be twice the first switching frequency f10.

Noise at the same frequency as the first switching frequency f10 may not be generated in some cases. Also in this case, the noises n11 and n12 corresponding to both the first switching frequency f10 and the rotation frequency fm of the motor 110 are generated symmetrically about the first switching frequency f10 .

In addition, in the motor system 100, noise (n11, n12, n14 to n17) due to the first switching frequency f10 and the rotation frequency fm of the motor 110 may also occur. In this case, , n12, n14 to n17 correspond to both the first switching frequency f10 and the rotation frequency fm of the motor 110. [

The frequencies of the noises n11, n12 and n14 to n17 generated by the first switching frequency f10 and the rotation frequency fm of the motor 110 are set to the first switching frequency f10 (For example, the frequency of the third noise f13) of the first switching frequency f10 or the integral multiple of the first switching frequency f10 (for example, the frequency of the third noise f13). In other words, in the motor system 100, the first noise (n11, n14, n16) of a relatively high frequency and the first noise (n11, n14, n16) of a relatively high frequency are compared with the first switching frequency f10 or a multiple of the first switching frequency f10 2 noise (n12, n15, n17) may occur.

Further, the plural pairs of noises (n11 and n12, n14 and n15, n16 and n17) can be generated symmetrically on the basis of an integer multiple of the first switching frequency f10 or the first switching frequency f10. In this case, the noise (n16, n17) whose frequency is relatively larger than the first switching frequency f10 or an integer multiple of the first switching frequency f10 is the frequency at which the first switching frequency f10 or the first switching frequency f10, (n11, n12, n14, n15) relatively close to an integer multiple of the frequency f10. Therefore, the noise n16, n17 whose frequency is relatively larger than the first switching frequency f10 or the integer multiple of the first switching frequency f10 may be hardly heard by the driver or the passenger.

The frequencies of the noises n11 to n17 generated in the motor system 100 change according to the operation of the motor 110. [ For example, when the rotation speed of the motor 110 is increased, the frequencies of the noise n11 to n17 generated in the motor system 100 increase. On the contrary, when the rotation speed of the motor 110 is decreased, The frequencies of the noise (n11 to n17) generated in the frequency band decrease. In the case of an electric vehicle, the moving speed of the vehicle 1 corresponds to the rotational speed of the wheel, and the rotational speed of the wheel corresponds to the rotational speed of the motor 110, so that the noise (n11 to n17 Of the vehicle 1 increases or decreases corresponding to the increase or decrease of the rotational speed of the vehicle 1. [

As shown in FIG. 4, noise (n11, n12, n16, n17) of some of the noises generated in the motor driving unit 130 may be included in the audio frequency band ZA. The driver or passenger in the vehicle 1 hears the noises (n11, n12, n16, n17) in the audible frequency band ZA.

The control unit 150 controls the frequency fn of the noise generated in the motor system 100 to be difficult for the human being to recognize by adjusting the switching frequency fs of the motor driving unit 130. More specifically, the control unit 150 variably controls the switching frequency fs so that no noise is generated in the audible frequency band ZA or only a relatively small intensity in the audible frequency band ZA Can be controlled so as not to occur.

In this case, the control unit 150 may not consider noise (n13 to n15) whose frequencies do not correspond to the audible frequency band ZA among the generated noises n11 to n17 in the control of the switching frequency fs have. Also, the control unit 150 may not consider noise (n16, n17) having relatively low intensity in controlling the switching frequency fs.

5 is a view briefly showing an example of noise generated in the motor system when it is controlled according to the first embodiment. In FIG. 5, f20 denotes a switching frequency, and n21 to n22 denote noise generated in the motor system 100.

5, the control unit 150 controls the switching frequency f20 (hereinafter referred to as a second switching frequency) so that the frequency of each generated noise n21 to n25 is equal to or greater than the reference frequency . The reference frequency may be defined as a frequency that is larger than the upper limit frequency f _a or the upper limit frequency f _{s of the} audible frequency band ZA, depending on the designer's selection.

According to one embodiment, the controller 150 determines whether the frequency of the lowest noise (n22, hereinafter referred to as lowest frequency noise) among the generated noises n21 to n25 is higher than the upper limit frequency of the audible frequency band ZA (f _a) and it is equal to or while the second change the switching frequency (f20) to exceed, the control. Here, the lowest frequency noise may include the lowest noise on a certain period of time, or the lowest noise within a certain period of time.

Referring to Equation (2), the frequency of the lowest frequency noise n22 may be given by Equation (3) below.

Here, f22 denotes the frequency of the lowest frequency noise (n22), and f20 denotes the controlled switching frequency. fm is the rotation frequency of the motor. Also, b may be 1, but is not limited to 1, and may have various values depending on an arbitrary selection of a designer or an experimental result.

Equation (3) can be expressed as Equation (4).

The second switching frequency f20 may be given as the sum of the frequency of the lowest frequency noise n22 and an integral multiple of the rotation frequency fm of the motor 110,

The control unit 150 determines the second switching frequency f20 in accordance with the sum of the frequency of the lowest frequency noise n22 and the integral multiple of the rotation frequency fm of the motor 110 and outputs the determined second switching frequency f20 ) will be equal to the upper limit frequency (f _a) of the audio frequency band to the frequency of the reference frequency, for example, low frequency noise (n22) for operation by the motor driving unit 130, or to be greater than the control according to the.

In this case, the control unit 150 receives the information about the rotation frequency fm of the motor 110 from a sensor for measuring the motor rotation frequency, or transmits the rotation frequency fm of the motor 110 through various methods ) And obtain the second switching frequency f20 by obtaining the sum of the frequency of the lowest frequency noise n22 at a specific point in time and the rotational frequency fm of the motor 110. [

In addition, the controller 150 adds the frequency of the lowest frequency noise n22 and the frequency of the noise n23 symmetric to the lowest frequency noise n22 and determines the second switching frequency f20 in proportion to the acquired sum .

More specifically, the control unit 150 calculates the sum of the frequency of the lowest-frequency noise n22 and the frequency of the noise n23 symmetric to the lowest-frequency noise n22, It is possible to obtain the second switching frequency f20 by dividing by 2 or 3. Since the frequency of the noise n23 symmetrical to the lowest frequency noise n22 is given by the sum of the second switching frequency f20 and an integral multiple of the rotation frequency fm of the motor 110, , It becomes possible to calculate the second switching frequency f20 in the same manner as in the expression (4).

If the rotation frequency fm of the motor 110 changes, the second switching frequency f20 determined by the controller 150 changes correspondingly to that shown in FIG. Therefore, as described in Equation (3), the frequency of the lowest frequency noise n22 can be kept substantially constant within the range equal to or exceeding the reference frequency f _a .

If the reference frequency is defined as the upper limit of the audible frequency f _a and the frequency of the lowest frequency noise n 22 is kept equal to the upper limit of the audible frequency f _a , Can be expressed.

The second switching frequency f20 may be given as the sum of the upper limit of the audible frequency f _a and an integral multiple of the rotational frequency fm of the motor 110, 1 " or " 1 ".

Therefore, the control unit 150 may determine the second switching frequency f20 based on Equation (5). Specifically, the controller 150 obtains information on the rotation frequency fm of the motor 110 and uses the rotation frequency fm of the motor 110 and the upper limit f _a of the audible frequency to perform the second switching The frequency f20 can be determined.

The control unit 150 divides the sum of the frequency of the noise n23 symmetric to the lowest frequency noise n22 and the upper limit of the audible frequency f _a by a real number other than 0 to obtain a second switching frequency f20 ). ≪ / RTI > The motor driving unit 130 is controlled by the thus determined second switching frequency f20.

The rotational frequency fm of the motor 110 increases or decreases in accordance with the operation of the vehicle 1 as described above so that the second switching frequency f20 determined by the control unit 150 increases or decreases correspondingly .

When the second switching frequency f20 is controlled as described above, it is possible to minimize a reduction in the operation efficiency of the motor driving unit 130 compared with the conventional method, for example, when the inverter switching frequency up method is used.

FIG. 6 is a view showing an example of noise generated in the motor system when the inverter switching frequency up method is used. FIG. 7 is a diagram illustrating noise generated when the inverter switching frequency up method is used, Fig.

As shown in FIG. 6, the method of increasing the inverter switching frequency means a method of controlling the motor driving unit 130 by setting the switching frequency (f30, hereinafter referred to as a third switching frequency) relatively high. That is, the third switching frequency f30 is set to be generally high as shown in FIG. 4 in order to prevent the audible noise of the generated noise N31 and N32 so that the lowest frequencies of all the noises N31 and N32 value is to be exceeded the upper limit (f _s) and the same or an upper limit (f _a) of the audio frequency band (ZA). In the inverter switching frequency upward method, the third switching frequency f30 is not variable but has a constant value.

According to such an inverter switching frequency up method, since the third switching frequency f30 must be set very high such that all the noises N31 and N32 exceed the audible frequency band, the switching loss of the motor driving unit 130 increases, The operation efficiency decreases and the components of the motor driving unit 130 must be able to perform operations according to the high switching frequency f30 so that the cost of each component of the motor driving unit 130 is increased .

On the other hand, referring to FIG. 7, since the second switching frequency f20 is variable and is substantially lower than the third switching frequency f30, the above-described problem can be solved. In other words, it is not necessary to set the second switching frequency f20 to be very high, and it becomes possible to limit or prevent the increase of the switching loss, the decrease of the operation efficiency, or the rise of the manufacturing cost. In addition, since the second switching frequency f20 is set higher than the first switching frequency f10 as necessary, it is possible to prevent the frequency of the noise from being included in the audible frequency band ZA. Therefore, when the switching frequency f20 is adjusted as in the above-described embodiment, the noise generated in the motor driving unit 130 (N21 - N21) can be reduced without increasing the switching loss of the motor driving unit 130, N25 can be made higher than the audible frequency band ZA so that the driver or the passenger can not recognize the noise N21 to N25 generated in the motor driving unit 130. [

8 is a view showing an example of noise generated in the motor system when it is controlled according to the second embodiment.

8, the reference frequency f _b may be defined to be lower than the upper frequency f _a of the audible frequency band ZA.

The controller 150, based on the upper limit frequency (f _a) a reference frequency defined lower than (f _b) of the audio frequency band (ZA), in the same manner described above, the switching frequency (f40, less than the fourth switching frequency Can be controlled. In this case, in the same way as described above, the control unit 150 determines whether the frequency of the lowest frequency among the plurality of noise N41 and N42 generated in the motor system 100, that is, the frequency of the lowest frequency noise N41, f _b ) or to exceed the reference frequency (f _b ). The determination of the fourth switching frequency f40 may be performed in the same manner as the determination of the switching frequency described with reference to Equations (2) to (5) described above, or a modification thereof.

The respective components of the motor system 100, for example, the components of the motor 110 and the motor driving unit 130, have inherent vibration characteristics determined by various factors such as structure and material. Depending on the vibration characteristics, each component of the motor system 100 can generate noise of small intensity (N41, N42) in spite of the application of current and / or voltage ripple corresponding to the switching frequency.

Thus, when generating a relatively noise (N41, N42) of a small strength according to the vibration characteristics of the noise (N41, N42) generated by the motor system 100, a unique reference frequency (f _b) is the audio frequency band ( user, such as is set lower than the upper limit frequency (f _a) of ZA) even if the frequency of the noise (N41, N42) of a small strength include all or some of the audio frequency band (ZA), the driver or the passenger is the generated noise (N41, N42).

Therefore, even if the reference frequency f _b is set to be relatively lower than that set in the first embodiment, the effect of improving the noise can be obtained. In this way, when the reference frequency f _b is set to be relatively lower, the fourth switching frequency f 40 is substantially equal to or lower than the second switching frequency f 20, as described in Equation (5) Therefore, problems such as an increase in switching loss due to an increase in switching frequency, a drop in operating efficiency, and an increase in manufacturing cost can be further improved.

9 is a diagram showing an example of noise generated in the motor system when it is controlled according to the third embodiment.

The control unit 150 determines the noise N51 due to the specific switching frequency f50 and the rotation frequency fm of the motor 110 as opposed to the first and second embodiments described above, , N52 may be controlled to be smaller than the reference frequency.

Here, the reference frequency may include the upper limit frequency (f _a) or the upper limit frequency (f _a) relatively low frequency (f _b) than the audio frequency band (ZA) of the audio frequency band (ZA). The noise N51 and N52 due to the specific switching frequency f50 and the rotation frequency fm of the motor 110 may include noise whose frequency is closest to the specific switching frequency f50 and symmetrical to each other have.

More specifically, when the motor driving unit 130 operates according to the fifth frequency f50, the control unit 150 calculates the noise level due to the switching frequency f50 and the rotation frequency fm of the motor 110 N51, N52) the frequency is the frequency of the relatively high noise (N52) a reference frequency (f _a, f _b) with the same or a reference frequency (the fifth switching frequency to be less than _{f a, f b) (f50} ) of You can decide. In this case, the frequency of the noise N52 having a relatively high frequency can be kept constant, and can be kept substantially equal to, for example, the reference frequency f _a , f _b .

The determination of the fifth switching frequency f50 can be performed through the same or a partially modified method as that shown in the above Equations 2 to 5. [

Since the components constituting the motor system 100 have inherent vibration characteristics, if the frequency of the noise N52 having a relatively high frequency is kept constant so as to be equal to or lower than the reference frequency , It is possible to obtain the effect that the user is less aware of the noise generated in the vehicle 1, or the effect that the overall noise can be reduced.

For example, if the switching frequency f50 is controlled so that the frequency of the relatively high noise N52 is kept constant so as to be equal to or lower than the reference frequency, the relatively low noise N51 The noise generated in the various devices in the vehicle 1 including the motor system 100, for example, the engine 180 and the like can be canceled each other, so that the noise in the vehicle 1 can be eliminated or reduced.

Various methods of controlling the switching frequencies f20, f40 and f50 have been described by the abnormal control section 150. However, the method by which the control section 150 controls the switching frequencies f20, f40 and f50 is not limited thereto Do not.

For example, various components or devices capable of blocking or absorbing sound in a predetermined frequency band on a path through which noise generated in the motor system 100 is transmitted to the interior space of the vehicle 1, for example, soundproof walls, A built-in part, a frame such as a dashboard, or the like may be provided. The control unit 150 controls and adjusts the switching frequency in a manner similar to that described above so that the generated noise can be cut off or absorbed by these parts or devices so that noise of a predetermined frequency band is generated in the motor system 100 It is possible.

10 is a block diagram of another embodiment of a vehicle.

10, the motor system 100 may include a motor system 100 and a battery 190 that supplies power to the motor system 100. The motor system 100 may include a motor 110, (130) and a controller (150). Further, the vehicle 1 may further include an engine 180 according to the embodiment. The motor 110 may include a stator 111, a coil 112, and a rotor 113. Since the motor system 100, the motor 110, the motor driving unit 130, the control unit 150 and the battery 190 have been described above, detailed description will be omitted.

The vehicle 1 may further include at least one of a speed measuring unit 161, an engine operation detecting unit 163 and a noise detecting unit 165 in one embodiment. The speed measuring unit 161, the engine operation sensing unit 163, and the noise sensing unit 165 may be used to determine a reference frequency.

At least one of the speed measuring unit 161, the engine operation detecting unit 163, and the noise detecting unit 165 is communicably connected to the controller 150. At least one of the speed measuring unit 161, the engine operation detecting unit 163 and the noise detecting unit 165 performs communication with the control unit 150 using a wired communication means such as a wire or a circuit And communicates with the control unit 150 using various wireless communication networks such as CAN communication, Wi-Fi, Wi-Fi Direct or Bluetooth. . The result of measurement or sensing by at least one of the speed measuring unit 161, the engine motion sensing unit 163 and the noise sensing unit 165 may be transmitted to the control unit 150.

Although the speed measuring unit 161, the engine operation detecting unit 163 and the noise detecting unit 165 are all shown in FIG. 10, the vehicle 1 need not necessarily include all of these units 161, 163, and 165 none. At least one of the speed measuring unit 161, the engine operation detecting unit 163, and the noise detecting unit 165 may be omitted.

The speed measuring section 161 is provided for measuring and acquiring the running speed of the vehicle 1. [ The speed measuring unit 161 may measure the traveling speed of the vehicle 1 based on the rotational frequency of the engine 180 or the rotational frequency of the wheel and may also measure the traveling speed of the vehicle 1, And calculate and obtain the traveling speed of the vehicle 1 by calculating the positional change of the vehicle 1 with respect to time. The speed measuring unit 161 can measure and obtain the traveling speed of the vehicle 1 by using various other methods. The speed measuring unit 161 may be implemented by the controller 150. [ In this case, the measurement result of the speed measuring unit 161 may be transmitted to the control unit 150 through a wire, a circuit, or a wireless communication network. Alternatively, the speed measuring unit 161 may be implemented using a device separate from the control unit 150. [ Lt; / RTI >

The engine operation detecting unit 163 can detect and determine whether the engine 180 is operating. In other words, when the engine 180 does not operate, the engine operation detecting unit 163 outputs the corresponding electrical signal to the control unit 150. When the engine 180 starts operating, And outputs the corresponding electrical signal to the controller 150. [ The engine motion sensing unit 163 may be implemented using a circuit that receives feedback of the driving signal of the engine 180 or may be implemented using a vibration sensor for sensing whether the engine 180 vibrates And may also be implemented using an acoustic sensor capable of sensing the noise generated by the engine 180. In addition, the engine motion detection unit 163 can be implemented using various devices for detecting whether or not the engine is operating.

The noise sensing unit 165 is provided to sense whether noise generated in at least one of the engine 180 and the motor system 100 is generated or to detect the magnitude of the noise. The noise sensing unit 165 may include a device or a device capable of outputting an electrical signal corresponding to a received sound wave, such as a transducer. The noise sensing unit 165 may be implemented using various devices capable of sensing sound. The detection result of the noise sensing unit 165 is transmitted to the controller 150.

The control unit 150 may determine the reference frequency based on data transmitted from at least one of the speed measuring unit 161, the engine operation detecting unit 163, and the noise detecting unit 165.

According to one embodiment, the control unit 150 can determine the reference frequency according to the speed of the vehicle 1 measured by the speed measuring unit 161. In this case, if the speed of the vehicle 1 measured by the speed measuring unit 161 is relatively high, the control unit 150 can determine the reference frequency to be relatively low accordingly. For example, the control unit 150 can determine the reference frequency in inverse proportion to the speed of the vehicle 1. [

When the speed of the vehicle 1 increases, various noises generated by running such as road surface noise, wind noise, etc. increase correspondingly. Therefore, the driver or the passenger or the like can hardly recognize the noise generated in the motor system 100 because of the road surface noise or the wind noise, which increases with the speed of the vehicle 1. In other words, even if the reference frequency is set relatively low, and thus a part of the noise generated in the motor system 100 is included in the audio frequency band ZA, the driver or passenger does not recognize such noise I can not.

For this reason, the higher the speed of the vehicle 1, the lower the reference frequency can be set, and the motor driving unit 130 can be controlled with a relatively smaller switching frequency. Accordingly, it is possible to further improve the switching loss and the operation efficiency of the motor driving unit 130.

According to another embodiment, the control unit 150 can determine the reference frequency based on the detection result of the engine motion sensing unit 163. [

For example, when the engine 180 is operating as a result of the detection of the engine operation detecting unit 163, the controller 150 may set the reference frequency to be relatively low in response to the engine 180 being operated. If the engine 180 is not operating, the control unit 150 may set the reference frequency to a relatively high value corresponding to the operation.

When the engine 180 is operated, the engine 180 generates a noise having a relatively greater intensity than the noise generated in the motor system 100. Therefore, even if the reference frequency is relatively low when the engine 180 is driven and the frequency of the noise generated in the motor system 100 is included in the audible frequency band ZA, So that it is hard to recognize the noise generated in the vehicle 100.

Accordingly, the control unit 150 can control the motor driving unit 130 by setting the reference frequency relatively lower when the engine 180 is driven. As a result, the control unit 150 can increase the switching loss of the motor driving unit 130 Reduction in operation efficiency and the like can be further improved.

According to another embodiment, the control unit 150 may determine the reference frequency based on the detection result of the noise sensing unit 165.

For example, if the noise is generated in the motor system 100 or the noise generated in the motor system 100 exceeds the reference value as a result of the detection by the noise detector 165, The reference frequency can be determined to be relatively high. In addition, if the noise is not generated in the motor system 100, or if the magnitude of the noise is lower than the reference value, the control unit 150 may determine the reference frequency to be relatively low.

By changing the reference frequency according to whether the noise is generated or not, the controller 150 can selectively prevent the noise from being included in the audible frequency band, It is possible to control the switching operation.

Hereinafter, one embodiment of a control method of a motor system and a control method of a vehicle will be described with reference to FIG.

11 is a flowchart of an embodiment of a method of controlling a motor system.

Referring to FIG. 11, a reference frequency can be determined (10). The reference frequency may be determined based on, for example, the audio frequency band. In this case, the reference frequency may be determined to be equal to the upper limit frequency of the audible frequency band, or may be determined to be larger than the upper limit frequency of the audible frequency band. Also, the reference frequency may be determined to be a frequency that is relatively lower than the upper limit of the audible frequency band according to the embodiment. If the reference frequency is set to be relatively higher or lower than the upper frequency of the audible frequency band, then the determined reference frequency may approximate the upper frequency of the audible frequency band.

11 shows an embodiment in which the determination step 10 of the reference frequency is performed prior to the other steps 11 to 16, but according to the embodiment, the reference frequency determination step 10 must always be preceded by But may be performed after several steps 11 to 14 preceding the step 15 of controlling the switching frequency based on the rotational frequency of the motor.

When the motor system starts to operate, an alternating current is applied to at least one of the plurality of switching elements of the motor driving unit (11), and each switching element of the motor driving unit is turned on / Off operation (12).

A current may be applied to each switching element in a predefined pattern such that current flows or does not flow in at least one coil of the motor according to a predefined pattern. At least one coil generates a magnetic field in accordance with the current flow, and the rotor of the motor rotates at a rotation frequency corresponding to the switching frequency as the magnetic field is generated (13).

The control unit obtains information about the rotational frequency of the motor (14). Information on the rotational frequency of the motor can be acquired using a sensor capable of measuring the rotational frequency, such as an encoder.

The control unit may control the switching frequency for the motor driving unit based on the information about the rotational frequency of the motor (15). In this case, the controller can determine and adjust the switching frequency using Equations (2) to (5). For example, the control unit can determine the switching frequency according to the sum of the frequency of the lowest frequency noise and an integral multiple of the rotation frequency of the motor.

As described above, when the switching frequency is determined, the motor driving unit operates according to the newly determined switching frequency, and thus the frequency of the noise generated in the motor system becomes equal to or exceeds the reference frequency (16).

According to the embodiment, as shown in FIG. 9, the control unit may control the frequency of the noise generated in the motor driving unit to be lower than the reference frequency.

The control method of the motor system described with reference to Fig. 11 is equally applicable to the control method of the vehicle.

When the control method of the motor system described above is applied to the control method of the vehicle, the reference frequency determination process 10 determines the running speed of the vehicle according to the embodiment, determines the reference frequency according to the running speed of the vehicle Measuring a noise generated in at least one of the motor and the motor driving unit and determining a reference frequency corresponding to whether the noise is generated or the magnitude of the noise and / And determining a reference frequency corresponding to whether the engine is driven or not.

The control method of the motor system and the control method of the vehicle according to the above embodiments can be implemented in the form of a program that can be driven by various computer devices. Here, the program may include program commands, data files, data structures, and the like, alone or in combination. The program may be designed and manufactured using machine code or high-level language code. The program may be specifically designed to implement the control method of the motor system and the control method of the vehicle described above, or may be implemented using various functions or definitions that are well known to those skilled in the art of computer software.

A program for implementing the control method of the motor system and the control method of the vehicle can be recorded in a recording medium readable by a computer. The recording medium readable by a computer includes, for example, a magnetic disk storage medium such as a hard disk or a floppy disk, an optical medium such as a magnetic tape, a compact disk (CD) or a digital versatile disk (DVD) A magneto-optical media such as a floppy disk and a semiconductor storage device such as a ROM, a RAM or a flash memory. And may include various types of hardware devices.

Although various embodiments of the motor system, the vehicle, the motor system control method and the vehicle control method have been described, the motor system, the vehicle, the motor system control method and the vehicle control method are limited to the above- no. Various embodiments that can be modified and modified based on the above-described embodiments can also be an example of the motor system, the vehicle, the motor system control method, and the vehicle control method, which are well known to those skilled in the art . For example, it should be understood that the techniques described may be performed in a different order than the described methods, and / or that components of the described systems, structures, devices, circuits, It is possible to obtain the same or similar result as the motor system, the vehicle, the motor system control method, and the vehicle control method described above even if it is replaced or replaced by the equivalent.

1: vehicle 100: motor system
110: motor 111: stator
112: coil 113: rotor
130: motor driving unit 150:
161: speed measuring unit 163: engine operation detecting unit
165: noise detection unit 180: engine
190: Battery

Claims (20)

A motor driver for operating at least one switching element or stopping operation according to the switching frequency;
A motor having a coil for generating a magnetic field in accordance with an applied current and a rotor for rotating at a rotation frequency corresponding to the switching frequency by the magnetic field, the current being applied according to the operation of the at least one switching element; And
And a control unit for controlling the switching frequency based on a rotation frequency of the motor and controlling the switching frequency such that the frequency of the switching frequency and the noise due to the rotation frequency of the motor is equal to or greater than a reference frequency Motor system. The method according to claim 1,
Wherein the control unit determines the switching frequency in proportion to a sum or difference of the reference frequency and the rotational frequency of the motor. The method according to claim 1,
Wherein the frequency of the noise generated in the motor driving unit and the motor is defined in proportion to the sum or difference of the switching frequency and the rotational frequency of the motor,
Wherein the control unit determines the switching frequency based on a frequency of a noise generated in the motor driving unit and the motor. The method according to claim 1,
Wherein the noise generated according to the switching frequency and the rotation frequency of the motor includes a first noise and a second noise having a relatively lower frequency than the first noise, wherein the frequency of the first noise and the frequency of the second noise are A motor system that is symmetrical with respect to a switching frequency. 5. The method of claim 4,
Wherein the control unit determines the switching frequency in proportion to a sum of a frequency of the first noise and a frequency of the second noise. 6. The method of claim 5,
Wherein the control unit controls the switching frequency such that a frequency of noise for the second noise exceeds a reference frequency. 6. The method of claim 5,
Wherein the reference frequency is defined based on a frequency of an audible frequency band. 8. The method of claim 7,
Wherein the frequency of the second noise comprises the upper frequency of the audible frequency band. 8. The method of claim 7,
Wherein the reference frequency is defined to be equal to or close to an upper limit frequency of the audible frequency band. 8. The method of claim 7,
Wherein the reference frequency is defined by further utilizing a vibration characteristic of at least one of the motor driving unit and the motor. A motor driver for operating at least one switching element or stopping operation according to the switching frequency;
A motor having a coil for generating a magnetic field in accordance with an applied current and a rotor for rotating at a rotation frequency corresponding to the switching frequency by the magnetic field, the current being applied according to the operation of the at least one switching element; And
And a control unit for controlling the switching frequency based on a rotation frequency of the motor and controlling the switching frequency such that the frequency of the switching frequency and the noise due to the rotation frequency of the motor is equal to or greater than a reference frequency vehicle. 12. The method of claim 11,
Wherein the control unit determines the switching frequency in proportion to a sum or difference of the reference frequency and the rotational frequency of the motor. 12. The method of claim 11,
A running speed obtaining unit for determining a running speed of the vehicle; And
A noise measuring unit for measuring noise generated in the motor and the motor driving unit; ≪ / RTI > 14. The method of claim 13,
Wherein the control unit determines the reference frequency by using at least one of the running speed of the vehicle and the noise. 12. The method of claim 11,
An engine for acquiring power for running the vehicle; And
And an engine operation detection unit for determining whether the engine is operating. 16. The method of claim 15,
And determines the reference frequency according to whether or not the engine is operating. Determining a reference frequency;
Operating the motor driving unit electrically connected to the motor based on the switching frequency;
The motor starting to drive and rotating at a rotation frequency corresponding to the switching frequency;
Controlling the switching frequency based on the rotational frequency of the motor such that the switching frequency and the frequency of the noise due to the rotational frequency of the motor are equal to or greater than a reference frequency A method of controlling a motor system. Determining a reference frequency;
Operating the motor driving unit electrically connected to the motor based on the switching frequency;
The motor starting to drive and rotating at a rotation frequency corresponding to the switching frequency;
Controlling the switching frequency based on the rotational frequency of the motor such that the switching frequency and the frequency of the noise due to the rotational frequency of the motor are equal to or greater than a reference frequency A method of controlling a vehicle. 19. The method of claim 18,
Wherein the determining the reference frequency comprises:
Determining a running speed of the vehicle; And
Measuring noise generated in the motor and the motor driving unit; Further comprising at least one of:
Wherein the step of determining the reference frequency further comprises the step of determining the reference frequency using at least one of the running speed of the vehicle and the noise. 19. The method of claim 18,
Wherein the determining the reference frequency comprises:
Determining whether the engine is running; And
And determining the reference frequency according to whether the engine is driven or not.

Images