JP2020058164A - Control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To appropriately control a motor while suppressing deterioration of a noise level related to a receiver. A control device (100) controls a motor (11) mounted on a vehicle (1). The control device includes a determination means (130) for determining the frequency of a carrier signal used to control an inverter (110) electrically connected to a motor. When the distance between the vehicle and the facility transmitting the broadcasting radio wave is long, the determination means determines a frequency lower than that when the distance is short as the frequency of the carrier signal. The determining means is a condition that the frequency of the carrier signal corresponding to the above distance is the first frequency lower than the predetermined frequency, and the current of the battery (12) as the power source of the motor is higher than the predetermined current value. When at least one of the conditions that the temperature of the reactor of the inverter is higher than the predetermined temperature is satisfied, the second frequency higher than the predetermined frequency is determined as the frequency of the carrier signal. [Selection diagram] Fig. 3

Description

  The present invention relates to a technical field of a control device that controls a motor mounted on a vehicle.

  For example, a high-frequency signal generated when a motor is controlled by this type of device may deteriorate the noise level of a broadcast radio wave receiver such as a radio. To solve this problem, for example, (i) the switching frequency of the DC-DC converter is set to a frequency that is an integral multiple of the difference between adjacent broadcast frequencies of the AM broadcast wave, or (ii) the tuning frequency of the AM broadcast wave is changed. A technique has been proposed in which a switching frequency is detected and a switching frequency is selected so that a frequency that is an integral multiple of the switching frequency of the DC-DC converter has a specified frequency difference with respect to a tuning frequency (see Patent Document 1).

JP-A-2002-335672

  In the technique described in Patent Document 1, the switching frequency is selected only from the viewpoint of eliminating the reception failure of the AM broadcast, and there is room for improvement.

  The present invention has been made in view of the above problems, and has as its object to provide a control device that can appropriately control a motor while suppressing deterioration of a noise level related to a receiver.

  A control device according to one aspect of the present invention is a control device for controlling a motor in a vehicle including a motor as a drive source, a battery as a power source of the motor, and a receiver capable of receiving broadcast radio waves. An inverter having one end electrically connected to the motor and the other end electrically connected to the battery; a generation unit configured to generate a carrier signal used for controlling the inverter; Determining means for determining the frequency of the carrier signal generated by the means; first detecting means for detecting a distance between the vehicle and a facility for transmitting the broadcast radio wave; and between the battery and the motor. Second detecting means for detecting a current flowing through the inverter, and third detecting means for detecting a temperature of a reactor included in the inverter. When the distance is long, a frequency lower than the case where the detected distance is short is determined as the frequency of the carrier signal, and the determining unit determines the frequency of the carrier signal corresponding to the detected distance, When the first frequency is lower than a predetermined frequency, at least one of a condition that the detected current is higher than a predetermined current value and a condition that the detected temperature is higher than a predetermined temperature is satisfied. In this case, a second frequency higher than the predetermined frequency is determined as the frequency of the carrier signal.

It is a block diagram showing the composition of the control device concerning an embodiment. FIG. 3 is a diagram illustrating an example of a relationship between a distance between a transmission source of a broadcast radio wave and a host vehicle, and a carrier frequency. 5 is a flowchart illustrating an operation of the control device according to the embodiment.

  An embodiment according to a control device will be described with reference to FIGS.

(Constitution)
A configuration of a control device according to the embodiment will be described with reference to FIG. FIG. 1 is a block diagram illustrating a configuration of a control device according to the embodiment.

  In FIG. 1, a control device 100 is mounted on a vehicle 1. The vehicle 1 includes a motor 11 as a drive source, a battery 12 as a power source for the motor 11, and a receiver 20 for broadcast radio waves such as a radio or a television.

  The control device 100 includes an inverter 110, a carrier signal generator 120, a carrier frequency selector 130, a distance detector 140, a current sensor 31, and a temperature sensor 32. Current sensor 31 detects a current flowing between motor 11 and battery 12. Temperature sensor 32 detects a temperature of a reactor (not shown) included in inverter 110.

  Inverter 110 has one end electrically connected to motor 11 and the other end electrically connected to battery 12. Carrier signal generating section 120 generates a carrier signal for controlling PWM (Pulse Width Modulation) of inverter 110. Note that various existing modes can be applied to the inverter 110 and the carrier signal generation unit 120, and a detailed description thereof will be omitted.

  The distance detection unit 140 determines a distance between the position of the vehicle 1 and a source of a broadcast radio wave (for example, a facility where a broadcast antenna is installed: hereinafter, appropriately referred to as a “base station”) (hereinafter, appropriately, “base station”). (Referred to as distance L "). Note that the position of the vehicle 1 may be acquired based on, for example, the output of a GPS (Global Positioning system). The position of the base station may be obtained based on, for example, map information. If the base station differs depending on the frequency of the broadcast wave received by the receiver 20, the position of the base station corresponding to the frequency of the broadcast wave currently received by the receiver 20 is determined based on the map information. You only need to get it.

  Carrier frequency selection section 130 selects the frequency of the carrier signal generated by carrier signal generation section 120. The carrier frequency selection unit 130 particularly selects the frequency of the carrier signal according to the distance L.

  Specifically, as shown in FIG. 2A, when distance L is shorter than distance L1, carrier frequency selecting section 130 selects frequency f1 as the frequency of the carrier signal. When distance L is greater than or equal to distance L1 and shorter than distance L2, carrier frequency selecting section 130 selects frequency f2 (<f1) as the frequency of the carrier signal. When the distance L is equal to or longer than the distance L2, the carrier frequency selection unit 130 selects the frequency f3 (<f2) as a frequency of the carrier signal in principle (exceptions will be described later).

  Here, as shown in FIG. 2B, the frequencies f1 and f2 are frequencies included in a frequency band suitable for protecting the inverter 110 from the viewpoint of thermal design. On the other hand, the frequency f3 is a frequency included in the frequency range of the carrier signal that can perform PWM control of the inverter 110 and is included in a frequency band in which the influence of the switching noise caused by the inverter 110 on the receiver 20 can be appropriately suppressed. . The frequency fb in FIG. 2B is a frequency at a boundary between the former frequency band and the latter frequency band. The frequency fb changes according to, for example, the specifications of the inverter 110 and the characteristics of the components that make up the inverter 110.

  Note that the carrier frequency selection unit 130 may select a frequency such that, for example, the longer the distance L, the lower the frequency of the carrier signal.

(motion)
The operation of the control device 100 configured as described above will be described with reference to the flowchart of FIG.

  3, the carrier frequency selection unit 130 determines whether or not the receiver 20 is ON (Step S101). In the process of step S101, if it is determined that the receiver 20 is not ON (that is, it is OFF) (step S101: No), the process ends. In this case, the carrier frequency selection unit 130 selects, for example, a frequency according to the operation state of the motor 11 as the frequency of the carrier signal. In this case, after a lapse of a predetermined time (for example, several tens to several hundreds of milliseconds), the process of step S101 is performed.

  In the process of step S101, when it is determined that the receiver 20 is ON (step S101: Yes), the distance detection unit 140 acquires position information indicating the position of the vehicle 1 (step S102). In the process of step S102, the distance L is further detected by the distance detecting unit 140. Then, the carrier frequency selection unit 130 acquires the detected distance L.

  Next, the carrier frequency selection unit 130 determines whether the distance L is shorter than the distance L1 (Step S103). In the process of step S103, when it is determined that the distance L is shorter than the distance L1 (step S103: Yes), the carrier frequency selecting unit 130 sets the frequency f1 as the frequency of the carrier signal (step S104). Thereafter, after a predetermined time has elapsed, the process of step S101 is performed (because the distance L changes if the vehicle 1 is running).

  In the process of step S103, when it is determined that the distance L is not shorter than the distance L1 (step S103: No), the carrier frequency selector 130 determines whether the distance L is shorter than the distance L2 (step S105). . In the process of step S105, when it is determined that the distance L is shorter than the distance L2 (step S105: Yes), the carrier frequency selection unit 130 sets the frequency f2 as the frequency of the carrier signal (step S106). Thereafter, after a predetermined time has elapsed, the process of step S101 is performed.

  In the process of step S105, when it is determined that the distance L is not shorter than the distance L2 (step S105: No), the carrier frequency selector 130 temporarily selects the frequency f3 as the frequency of the carrier signal (step S107). In parallel with or before or after the process of step S107, the carrier frequency selection unit 130 acquires the battery current Ib detected by the current sensor 31 (step S108), and outputs the battery current Ib to the inverter 110 detected by the temperature sensor 32. The temperature LT of the included reactor is obtained (step S109).

  Next, the carrier frequency selection unit 130 determines whether at least one of the first condition that the battery current Ib is greater than the threshold current Ibth and the second condition that the temperature LT is greater than the threshold temperature LTth is satisfied. A determination is made (step S110). In the process of step S110, when it is determined that at least one of the above conditions is satisfied (step S110: Yes), the carrier frequency selection unit 130 selects the frequency f2 instead of the frequency f3 as the frequency of the carrier signal ( Step S111). Thereafter, after a predetermined time has elapsed, the process of step S101 is performed. The processing in step S111 corresponds to an exception when the distance L is equal to or longer than the distance L2.

  In the process of step S110, when it is determined that neither the first condition nor the second condition is satisfied (step S110: No), the carrier frequency selection unit 130 selects the frequency f3 as the frequency of the carrier signal. I do. Thereafter, after a predetermined time has elapsed, the process of step S101 is performed.

  The threshold current Ibth is a value that determines whether or not the frequency of the carrier signal should be different from the frequency (here, frequency f3) corresponding to the distance L (here, frequency f2). It is set as a fixed value or as a variable value according to some physical quantity or parameter. Such a threshold current Ib is set empirically, experimentally, or by simulation, for example, by obtaining the relationship between the battery current Ib and the heat generation amount of the reactor caused by the battery current Ib, and based on the obtained relationship. do it.

  The threshold temperature LTth is a value that determines whether the frequency of the carrier signal is different from the frequency corresponding to the distance L, similarly to the threshold current Ib, and is a fixed value in advance, or a physical quantity or It is set as a variable value according to the parameter. Such a threshold temperature LTth may be set as a value smaller than the upper limit value of the allowable temperature range by a predetermined value based on, for example, an allowable temperature range based on the temperature characteristics of the reactor and a detection error of the temperature sensor 32.

(Technical effect)
According to the study of the present inventor, the following matters have been found. That is, when the frequency of the carrier signal increases, the frequency characteristic of the switching noise caused by the inverter 110 changes, and the noise level increases. On the other hand, when the frequency of the carrier signal decreases, the noise level decreases, but the temperature of the reactor included in inverter 110 tends to increase.

  The intensity of the broadcast radio wave received by the receiver 20 decreases as the vehicle 1 moves away from the base station transmitting the broadcast radio wave. When the frequency of the carrier signal is constant, the influence of the switching noise caused by the inverter 110 on the receiver 20 increases as the distance L between the vehicle 1 and the base station increases.

  In the control device 100, when the distance L is relatively long, the carrier frequency selection unit 130 selects a lower frequency as the frequency of the carrier signal than when the distance L is relatively short. As a result, when the distance L is relatively long, the noise level is reduced as compared with when the distance L is relatively short.

  On the other hand, when the distance L is relatively long (in the present embodiment, when the distance L is equal to or longer than the distance L2), the first condition that the battery current Ib is larger than the threshold current Ibth and the temperature LT is the threshold temperature On the condition that at least one of the second conditions that is larger than LTth is satisfied, the carrier frequency selecting unit 130 sets a frequency higher than the frequency (the frequency f3 in the present embodiment) (corresponding to the frequency f3 in the present embodiment) corresponding to the distance L. , Frequency f2) are selected as the frequency of the carrier signal. As a result, the temperature rise of the reactor due to the decrease in the frequency of the carrier signal is suppressed, and the noise level is reduced to some extent.

  As described above, according to the control device 100, it is possible to achieve both the suppression of the influence of the switching noise caused by the inverter 110 on the receiver 20 and the protection of the inverter 110.

  Various aspects of the invention derived from the embodiments described above will be described below.

  A control device according to one aspect of the present invention is a control device that controls the motor in a vehicle including a motor as a driving source, a battery as a power source of the motor, and a receiver capable of receiving broadcast radio waves. An inverter having one end electrically connected to the motor and the other end electrically connected to the battery; generating means for generating a carrier signal used for controlling the inverter; and the generating means Determining means for determining the frequency of the carrier signal generated by the first and second detecting means, a first detecting means for detecting the distance between the vehicle and the facility that emits the broadcast radio wave, between the battery and the motor A second detecting means for detecting a flowing current; and a third detecting means for detecting a temperature of a reactor included in the inverter, wherein the determining means is configured to detect the detected current. If the separation is long, a lower frequency than the case where the detected distance is short is determined as the frequency of the carrier signal, and the determination unit determines the frequency of the carrier signal corresponding to the detected distance, When the first frequency is lower than a predetermined frequency, at least one of a condition that the detected current is higher than a predetermined current value and a condition that the detected temperature is higher than a predetermined temperature is satisfied. In this case, a second frequency higher than the predetermined frequency is determined as the frequency of the carrier signal.

  In the above-described embodiment, the “carrier signal generation unit 120” corresponds to an example of a “generation unit”, the “carrier frequency selection unit 130” corresponds to an example of a “determination unit”, and the “distance detection unit 140” The “current sensor 31” corresponds to an example of a “second detection unit”, and the “temperature sensor 32” corresponds to an example of a “third detection unit”. The “threshold current Ibth” according to the above-described embodiment corresponds to an example of a “predetermined current value”, the “threshold temperature TLth” corresponds to an example of a “predetermined temperature”, and the “frequency fb” is an example of a “predetermined frequency”. , And “frequency f3” corresponds to an example of “first frequency”, and “frequency f2” corresponds to an example of “second frequency”.

  In the control device, when the distance detected by the first detection means (that is, the distance between the vehicle and the facility that transmits the broadcast wave) is long, a lower frequency is used as compared with the case where the distance is short. It is determined as the frequency of the signal. The longer the distance, the lower the intensity of the broadcast radio wave received by the receiver, but the lower the frequency of the carrier signal, the lower the noise level caused by the inverter. Deterioration of the level is suppressed.

  However, when the frequency of the carrier signal decreases, the temperature of the reactor included in the inverter tends to increase. For this reason, in the control device, from the viewpoint of protection of components such as a reactor, even when the frequency of the carrier signal corresponding to the distance is the first frequency, the current detected by the second detection unit is a predetermined value. When at least one of the condition that the current value is higher than the current value and the condition that the temperature detected by the third detection unit is higher than the predetermined temperature is satisfied, the second frequency higher than the first frequency is the carrier signal of the carrier signal. Determined as frequency. As a result, the temperature rise of the reactor is suppressed. In addition, it can be expected that the deterioration of the noise level of the receiver is suppressed to some extent.

  As described above, according to the control device, it is possible to appropriately control the motor while suppressing, for example, thermal deterioration of the inverter while suppressing deterioration of the noise level of the receiver.

  The present invention is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist or idea of the invention which can be read from the claims and the entire specification, and a control device with such a change is also available. Also, they are included in the technical scope of the present invention.

  DESCRIPTION OF SYMBOLS 1 ... Vehicle, 11 ... Motor, 12 ... Battery, 20 ... Receiver, 31 ... Current sensor, 32 ... Temperature sensor, 100 ... Control device, 110 ... Inverter, 120 ... Carrier signal generation part, 130 ... Carrier frequency selection part, 140 ... Distance detector

Claims (1)

A control device for controlling the motor in a vehicle including a motor as a drive source, a battery as a power source of the motor, and a receiver capable of receiving broadcast radio waves,
An inverter having one end electrically connected to the motor and the other end electrically connected to the battery;
Generating means for generating a carrier signal used for controlling the inverter;
Determining means for determining the frequency of the carrier signal generated by the generating means,
First detection means for detecting a distance between the vehicle and a facility that transmits the broadcast radio wave;
Second detection means for detecting a current flowing between the battery and the motor;
Third detection means for detecting a temperature of a reactor included in the inverter;
With
The determining means, when the detected distance is long, determines a lower frequency than the case where the detected distance is short, as the frequency of the carrier signal,
The determining means is a case where the frequency of the carrier signal corresponding to the detected distance is a first frequency lower than a predetermined frequency, and a condition that the detected current is higher than a predetermined current value; When at least one of the conditions that the detected temperature is higher than a predetermined temperature is satisfied, a second frequency higher than the predetermined frequency is determined as the frequency of the carrier signal.

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