vehicle

Abstract

Suppresses electromagnetic noise. [Solution] The vehicle comprises a motor, an inverter connected to the motor, a battery that supplies power to the inverter, an impedance adjustment circuit provided between the inverter and the battery, and a control device that controls the impedance adjustment circuit. The control device comprises one or more processors, and the processors perform the following processes: obtaining the current value and current phase difference flowing through the motor (S102), deriving the inverter impedance, which is the impedance of the inverter with respect to the battery, from the current value and current phase difference (S106), and adjusting the impedance of the impedance adjustment circuit so that the difference between the battery impedance, which is the impedance of the battery with respect to the inverter, and the inverter impedance becomes small (S108).

Description

[Technical Field]

[0001] This invention relates to a vehicle. [Background technology]

[0002] When the voltage applied to a long wire changes abruptly, reflection occurs at the end of the wire, causing an overshoot in the signal voltage. Also, if the wire is branched, an imbalance in the length of the branched wires can easily cause ringing due to the back-and-forth of reflected signals. Patent Document 1 describes inserting a damping resistor fixedly into the output terminal of the voltage to mitigate voltage changes and prevent signal reflection at the end of the wire. [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2011-217558 [Overview of the Initiative] [Problems that the invention aims to solve]

[0004] Vehicles utilize numerous electrical components, which can generate electromagnetic noise. Electric vehicles, in particular, drive motors with high voltage and current, making them susceptible to electromagnetic noise generation in their various electrical components. This noise propagates to the roof antenna and interferes with radio broadcast waves, resulting in radio noise. One example of electromagnetic noise is ringing noise, which occurs when switching elements are switched on or off, causing distortion in current and voltage waveforms. The electromagnetic field formed by this ringing noise interferes with radio broadcast waves, resulting in the aforementioned radio noise.

[0005] In view of these problems, the present invention aims to provide a vehicle capable of suppressing electromagnetic noise. [Means for solving the problem]

[0006] To solve the above problems, a vehicle according to one embodiment of the present invention is provided. Motor and, An inverter connected to the motor, A battery that supplies power to the inverter, An impedance adjustment circuit is provided between the inverter and the battery, A control device for controlling the impedance adjustment circuit, Equipped with, The control device is Equipped with one or more processors, The aforementioned processor, To obtain the current value and current phase difference flowing through the motor, The inverter impedance, which is the impedance of the inverter with respect to the battery, is derived from the current value and the current phase difference. The impedance of the impedance adjustment circuit is adjusted so that the difference between the battery impedance, which is the impedance of the battery relative to the inverter, and the inverter impedance becomes small. Execute the process that includes this. [Effects of the Invention]

[0007] According to the present invention, it is possible to suppress electromagnetic noise. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 is a schematic diagram of a vehicle. [Figure 2] Figure 2 is a flowchart showing the flow of the impedance adjustment method. [Figure 3] Figure 3 is an explanatory diagram illustrating the inductance map with respect to the d-axis. [Figure 4] Figure 4 is an explanatory diagram illustrating the inductance map with respect to the q-axis. [Figure 5] Figure 5 is a circuit diagram illustrating an impedance matching circuit. [Figure 6] Figure 6 is a circuit diagram showing another example of an impedance matching circuit. [Modes for carrying out the invention]

[0009] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. The dimensions, materials, and other specific numerical values ​​shown in these embodiments are merely examples to facilitate understanding of the invention and do not limit the present invention unless otherwise specified. In this specification and drawings, elements having substantially the same function and configuration are denoted by the same reference numerals to avoid redundant explanations, and elements not directly related to the present invention are omitted from the illustration.

[0010] Figure 1 is a schematic diagram of vehicle 100. In Figure 1, arrow F indicates the vehicle's forward direction, arrow B indicates the vehicle's reverse direction, arrow R indicates the vehicle's rightward direction, and arrow L indicates the vehicle's leftward direction.

[0011] Here, vehicle 100 is exemplified as a hybrid vehicle equipped with two drive sources, an engine 110 and a motor 120. However, vehicle 100 is not limited to hybrid vehicles; various types of vehicles can be used, such as electric vehicles that use only the motor 120 as a drive source.

[0012] As shown in Figure 1, the vehicle 100 includes an engine 110, a motor 120, a clutch 130, a transmission 140, an inverter 150, a battery 160, an impedance adjustment circuit 170, a propeller shaft 180, a front differential gear 190, a front drive shaft 200, front wheels 210, a rear differential gear 220, a rear drive shaft 230, rear wheels 240, and a control device 300.

[0013] Engine 110 consists of a gasoline engine or a diesel engine. Engine 110 obtains driving force by burning fuel such as gasoline or diesel oil supplied from a fuel tank (not shown). Engine 110 transmits the obtained driving force to the transmission 140 via a clutch 130. Engine 110 is connected to a control device 300, and the operation of the injectors and spark plugs is controlled based on control commands from the control device 300, thereby adjusting the driving force.

[0014] The motor 120 is composed of, for example, a permanent magnet synchronous motor. Alternatively, instead of a permanent magnet synchronous motor, a wound-field synchronous motor with the same voltage equation as the permanent magnet synchronous motor can be used for the motor 120. The motor 120 is mounted coaxially with the engine 110. The motor 120 obtains driving force from power supplied from the battery 160 via the inverter 150. The motor 120 transmits the obtained driving force to the transmission 140. Furthermore, the motor 120 also functions as a generator when not receiving power. The power generated by the motor 120 is stored in the battery 160 via the inverter 150.

[0015] In this embodiment, the UVW phase of the motor 120 is equipped with an ammeter capable of measuring the effective value of the phase current in each phase. The motor 120 is also equipped with a resolver capable of identifying the current phase difference, which is the phase difference between the winding current and the applied voltage.

[0016] The driving force output from power sources such as the engine 110 and motor 120 is adjusted in torque, rotational speed, and direction by the transmission 140 and transmitted to the propeller shaft 180. The driving force transmitted to the propeller shaft 180 is then transmitted to the front wheels 210 via the front differential gear 190 and front drive shaft 200. In addition, the driving force transmitted to the propeller shaft 180 is also transmitted to the rear wheels 240 via the rear differential gear 220 and rear drive shaft 230.

[0017] The inverter 150 converts the DC power supplied from the battery 160 into three-phase AC power and supplies it to the motor 120. The inverter 150 is connected to the control device 300 and adjusts the driving force of the motor 120 based on the control commands of the control device 300.

[0018] The battery 160 primarily stores electrical energy that drives the motor 120. The voltage of the battery 160 is, for example, between 300V and 400V.

[0019] The impedance adjustment circuit 170 is installed between the inverter 150 and the battery 160. The impedance adjustment circuit 170 is connected to the control device 300 and can switch its own impedance based on control commands from the control device 300.

[0020] The control device 300 controls the entire vehicle 100. The control device 300 includes one or more processors 300a and one or more memories 300b connected to the processors 300a. The processors 300a include, for example, a CPU (Central Processing Unit). The memories 300b include, for example, ROM (Read Only Memory) and RAM (Random Access Memory). ROM is a memory element that stores programs and calculation parameters used by the CPU. In this embodiment, the ROM also holds an inductance map, which will be described later. RAM is a memory element that temporarily stores data such as variables and parameters used in processing performed by the CPU.

[0021] The control device 300 communicates with various devices installed in the vehicle 100, such as the engine 110, inverter 150, impedance adjustment circuit 170, and motor 120. Communication between the control device 300 and each device is achieved, for example, using CAN (Controller Area Network) communication.

[0022] The functions of the control device 300 according to this embodiment may be divided among multiple devices, or multiple functions may be realized by a single device. If the functions of the control device 300 are divided among multiple devices, these multiple devices may be connected to each other via a communication bus such as CAN.

[0023] Vehicle 100 uses many electrical components, such as the drive motor 120. These electrical components can generate electromagnetic noise. This electromagnetic noise propagates to the roof antenna of vehicle 100 and interferes with radio broadcast waves, resulting in radio noise. One example of electromagnetic noise is ringing noise, which occurs when the ON / OFF state of switching elements distorts the current waveform or voltage waveform. When the electromagnetic field formed by ringing noise interferes with radio broadcast waves, it becomes radio noise.

[0024] Electromagnetic noise, such as ringing noise, is often caused by impedance mismatch at the termination points of wiring. If the impedance is not matched at the termination points of wiring, for example, between inverter 150 and battery 160, a portion of the signal will be reflected at those termination points, causing distortion in the signal and current waveforms (voltage waveforms).

[0025] Therefore, in this embodiment, electromagnetic noise is suppressed by making the impedance of the battery 160 that supplies power equal to the impedance of the inverter 150 that receives power. Hereinafter, the impedance of the battery 160 with respect to the inverter 150 may be referred to as the battery impedance. Also, the impedance of the inverter 150 with respect to the battery 160 may be referred to as the inverter impedance. Thus, the inverter impedance represents the impedance of the entire inverter motor system consisting of the inverter 150 and the motor 120.

[0026] However, the inverter impedance is not fixed and changes depending on the operating state of the motor 120. The operating state of the motor 120 is determined by the phase voltage V applied to the motor 120. u , V v , Vw It is determined by the d-axis current, q-axis current, and current phase difference flowing through the motor 120. When the d-axis inductance and q-axis inductance change as the d-axis current, q-axis current, and current phase difference flowing through the motor 120 change, the impedance of the entire motor 120 also changes.

[0027] As described above, the inverter impedance includes not only the impedance of the motor 120 but also the impedance of the inverter 150. However, when the motor 120 is controlled at a high frequency, the inductance of the motor 120 becomes dominant as the inverter impedance. Here, the impedance of the motor 120 is targeted as the inverter impedance, and the impedance of the inverter 150 itself is ignored.

[0028] FIG. 2 is a flowchart showing the flow of the impedance adjustment method. Such an impedance adjustment method is repeatedly executed at a predetermined interrupt period. Note that the control device 300 executes the processing from step S101 in parallel when the next interrupt period arrives even if all the processing in steps S101 to S108 has not been completed.

[0029] (Command value transmission process S101) The control device 300 derives, for example, the required torque of the motor 120 according to the operation of the accelerator pedal by the driver of the vehicle 100, and transmits a command value based on the required torque to the inverter 150. The inverter 150 determines the phase voltages V u V v V w and the voltage advance angle according to the command value, and performs advance angle control of the motor 120.

[0030] Specifically, the inverter 150 derives the d-axis current i d and q-axis current i q as command values from the required torque, and determines the phase voltages V u V v V wThe following equation is derived. In equation 1, R is the winding resistance, φ is the flux linkage of the magnet, ω is the electrical angular velocity, and L is the d-axis inductance. d q-axis inductance L q This is the value derived in the inductance identification process S103 in the previous impedance adjustment method. Also, the inverter 150 has a d-axis current i d , q-axis current i q The voltage advance angle is determined from the torque estimate.

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[0031] (Current and phase difference acquisition process S102) d-axis inductance L in motor 120 d q-axis inductance L q The magnetic flux can be determined from the flux linkage and magnetic flux of the magnet, which are generated by passing current through the d-axis and q-axis respectively, according to the voltage equation for permanent magnets. The magnetic flux of the magnet is determined by the type and shape of the magnet, etc. The d-axis current i affects the flux linkage. d , q-axis current i q The phase current i of each of the UVW phases is u i v i w It can be determined by the current phase difference θ.

[0032] The control device 300 receives the phase current i from the ammeters inserted into each of the UVW phases of the motor 120. u i v i w The control device 300 obtains the current phase difference θ by multiplying the mechanical angle of the resolver of the motor 120 by the number of pole pairs. The control device 300 obtains the phase current i for each of the UVW phases. u i v i w And the d-axis current i is based on the current phase difference θ and the following equation 2. d , q-axis current i q The following is derived. Note that the phase current i for each of the UVW phases is also given. u i v i w , d-axis current id , q-axis current i q This is the effective value.

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[0033] (Inductance identification process S103) The control device 300 refers to the inductance map and controls the d-axis current i d , q-axis current i q Based on the current phase difference θ, the d-axis inductance L d q-axis inductance L q Identify.

[0034] Figure 3 is an explanatory diagram illustrating the inductance map for the d-axis, and Figure 4 is an explanatory diagram illustrating the inductance map for the q-axis. As shown in Figures 3 and 4, the inductance map is provided with multiple d-axis currents i at predetermined intervals. d , q-axis current i q This is a table that uniquely determines the inductance using multiple current phase differences θ provided at predetermined intervals.

[0035] For example, in Figure 3, the d-axis current i d If the current is 100A and the current phase difference θ is 45°, then the d-axis inductance L d This becomes 0.24. Also, in Figure 4, the q-axis current i q If the current is 100A and the current phase difference θ is 45°, then the q-axis inductance L q This becomes 0.41. Note that the control device 300 controls the d-axis current i, which is not shown in the inductance map. d , q-axis current i q And for the current phase difference θ, the values ​​shown in the inductance map are linearly interpolated to obtain the d-axis inductance L d q-axis inductance L q Derive the following.

[0036] (Inductance conversion process S104) The control device 300 has a d-axis inductance L d and q-axis inductance L q The axis is transformed based on equation 3, and the U-phase inductance L u V-phase inductance L V W-phase inductance L W Derive the following.

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[0037] (Composite inductance derivation process S105) The control device 300 has a U-phase inductance L u V-phase inductance L V W-phase inductance L W Based on the following equation 4, the equivalent inductance L I Derive the following.

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[0038] (Impedance derivation process S106) The control device 300 controls the inverter impedance Z I =2πfL I Combined inductance L I Substitute this into the inverter impedance Z I We derive the following. Note that f is the frequency, for example, 1 MHz.

[0039] (Adjustment impedance derivation process S107) The control device 300 controls the battery impedance Z B and inverter impedance Z I Compare this with the adjustment impedance Z that needs to be adjusted. d The following is derived. Specifically, the control device 300 uses the battery impedance Z B From inverter impedance Z I Subtract the adjusted impedance Z d We seek.

[0040] (Impedance adjustment process S108) The control device 300 adjusts the battery impedance Z through the impedance adjustment circuit 170. B and inverter impedance Z I It is impedance-matched with that.

[0041] Figure 5 is a circuit diagram illustrating an impedance adjustment circuit 170. The impedance adjustment circuit 170 is constructed by connecting multiple inductors L in series and connecting multiple switches S in parallel between the inductors L. Adjustment impedance Z d If it is a positive value, that is, the battery impedance Z B The inverter impedance Z I If it is larger, the impedance summing circuit 170a located on the left of Figure 5 adjusts the impedance on the inverter 150 side with reference to the battery 160, impedance Z d Add only the minutes.

[0042] In the impedance summing circuit 170a, four levels of impedance Z1, Z2, Z3, and Z4 can be achieved by turning switches S1, S2, S3, and S4 ON / OFF. For example, by turning switch S1 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z1=0. By turning switch S2 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z2. By turning switch S3 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z3. By turning switch S4 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z4.

[0043] The absolute values ​​of the impedances are in the relationship: impedance Z1 < impedance Z2 < impedance Z3 < impedance Z4. The control device 300 adjusts the impedance Z1 out of the four levels of impedance Z1, Z2, Z3, and Z4. dThe control device 300 identifies the impedance that is closest to the identified impedance. Then, it operates switches S1, S2, S3, and S4 to achieve the identified impedance.

[0044] For example, adjustment impedance Z d Let's assume that the impedance is +10Ω. Then, if f is 1MHz, the inductance L of the impedance adjustment circuit 170 should be L=Z / 2πf=1.6μH. Now, let's assume that the inductance L of each inductor in the impedance adjustment circuit 170 is 1μH. In this case, the control device 300 turns on switch S3. Thus, the impedance of the impedance adjustment circuit 170 becomes 2.0μH, which is close to 1.6μH.

[0045] Also, adjustment impedance Z d If the value is negative, that is, the battery impedance Z B The inverter impedance Z I If it is smaller, the impedance subtraction circuit located on the right of Figure 5 adjusts the impedance on the inverter 150 side relative to the battery 160, impedance Z d Subtract the amount corresponding to the minute.

[0046] The impedance subtraction circuit 170b achieves three impedance levels, Z5, Z6, and Z7, by switching switches S5, S6, and S7 ON / OFF. For example, by turning switch S5 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z5. By turning switch S6 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z6. By turning switch S7 ON, the impedance of the impedance adjustment circuit 170 becomes impedance Z7.

[0047] The absolute values ​​of the impedances are in the relationship: impedance Z5 < impedance Z6 < impedance Z7. The control device 300 adjusts the impedance Z5 out of the three impedance levels Z5, Z6, and Z7. dIdentify the impedance closest to it. Then, the control device 300 operates switches S5, S6, and S7 so that the identified impedance is obtained.

[0048] Here, an example in which the impedance subtraction circuit 170b is constituted by an inductor L has been given. However, it is not limited to such a case, and it can also be constituted by a capacitor C.

[0049] FIG. 6 is a circuit diagram showing another example of the impedance adjustment circuit 170. In the impedance subtraction circuit 170c, three-stage impedances Z8, Z9, Z 10 are realized by the ON / OFF of S8, S9, S 10 . For example, by turning on switch S8, the impedance of the impedance adjustment circuit 170 becomes impedance Z8. Also, by turning on switch S9, the impedance of the impedance adjustment circuit 170 becomes impedance Z9. Also, by turning on switch S 10 , the impedance of the impedance adjustment circuit 170 becomes impedance Z 10 .

[0050] The absolute value of the impedance has a relationship of impedance Z8 < impedance Z9 < impedance Z 10 . The control device 300 identifies the impedance closest to the adjustment impedance Z 10 among the three-stage impedances Z8, Z9, Z d . Then, the control device 300 operates switches S8, S9, S 10 so that the identified impedance is obtained.

[0051] In this way, it is possible to match the battery impedance Z B and the inverter impedance Z I and suppress electromagnetic noise. Here, since the generation of ringing noise can also be suppressed, it is possible to reduce the interference with radio broadcast waves.

[0052] Also, by repeatedly executing each process of such an impedance adjustment method at a predetermined cycle, the inverter impedance Z that changes according to the operating state of the motor 120 I can be impedance-matched in real time.

[0053] In this embodiment, the control device 300 acquires the phase currents i u , i v , i w and the current phase difference θ from the ammeter and resolver provided in the motor 120, and an example of adjusting the impedance adjustment circuit 170 has been described. However, not limited to such an example, for example, the control device 300 may adjust the impedance adjustment circuit 170 based on the command values of the phase voltage and the voltage advance angle. However, in this case, it takes time until the command value is reflected as the operation of the motor 120. Therefore, the control device 300 may derive the adjustment impedance Z d and wait for the delay until it is reflected as the operation of the motor 120, and then adjust the impedance adjustment circuit 170.

[0054] Also, in this embodiment, the control device 300 refers to the inductance maps independent for the d-axis and the q-axis, and based on the d-axis current i d , the q-axis current i q , and the current phase difference θ, an example of specifying the d-axis inductance L d , the q-axis inductance L q has been described. However, not limited to such an example, the control device 300 may refer to one inductance map and specify the d-axis inductance L d , the q-axis inductance L q at once based on the d-axis current i d , the q-axis current i q , and the current phase difference θ. Also, the control device 300 is not limited to the d-axis current i d , the q-axis current i q , and based on the phase currents i u , i v , i w for each of the UVW phases and the current phase difference θ, the d-axis inductance Ld q-axis inductance L q It would also be acceptable to specify it.

[0055] Preferred embodiments of the present invention have been described above with reference to the attached drawings, but it goes without saying that the present invention is not limited to these embodiments. It will be obvious to those skilled in the art that various modifications or alterations can be conceived within the scope of the claims, and these will naturally also fall within the technical scope of the present invention.

[0056] The series of processes performed by each device (e.g., the control device 300) according to the above embodiment may be implemented using software, hardware, or a combination of software and hardware. The program constituting the software is pre-stored in a non-transitory storage medium provided inside or outside each device. The program is then read from the non-transitory storage medium (e.g., ROM) to a temporary storage medium (e.g., RAM) and executed by a processor such as a CPU.

[0057] It is possible to create programs to implement each of the above-mentioned devices and install them on the computers of each device. The processor executes the programs stored in memory to perform the processing of each of the above-mentioned functions. At this time, the program may be divided and executed by multiple processors, or it may be executed by a single processor. Alternatively, each of the above-mentioned functions may be implemented through cloud computing using multiple computers interconnected by a communication network. The programs may also be provided to the computers of each device and installed by distribution from an external device via a communication network. [Explanation of Symbols]

[0058] 100 vehicles 120 motor 150 Inverter 160 batteries 170 Impedance Adjustment Circuit 300 Control device

Claims

1. Motor and, An inverter connected to the motor, A battery that supplies power to the inverter, An impedance adjustment circuit is provided between the inverter and the battery, A control device for controlling the impedance adjustment circuit, Equipped with, The control device is Equipped with one or more processors, The aforementioned processor, To obtain the current value and current phase difference flowing through the motor, The inverter impedance, which is the impedance of the inverter with respect to the battery, is derived from the current value and the current phase difference. The impedance of the impedance adjustment circuit is adjusted so that the difference between the battery impedance, which is the impedance of the battery relative to the inverter, and the inverter impedance becomes small. A vehicle that performs a process that includes the following.

2. The vehicle according to claim 1, wherein the impedance adjustment circuit is configured by connecting a plurality of inductors in series and a plurality of switches in parallel from between the inductors.

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