JP5206564B2 - Switching device - Google Patents

Description

  The present invention relates to a DCDC converter that converts a DC input voltage into a DC voltage having a different voltage value and outputs the DCDC converter, and relates to a switching device that operates a switching element included in the DCDC converter.

  For example, Patent Document 1 below proposes a technique for connecting a plurality of DCDC converters in parallel. Thus, the output current can be appropriately controlled by driving the plurality of DCDC converters at the same switching frequency.

JP 2001-57779 A

  By the way, when driving a plurality of DCDC converters at the same switching frequency, there is a problem that noise increases at this frequency and the frequency of the higher harmonics.

  The present invention has been made to solve the above-mentioned problems, and its object is to use a plurality of DCDC converters which convert a DC input voltage into a DC voltage having a different voltage value and output the DC voltage. An object of the present invention is to provide a switching device capable of suitably suppressing the noise when driven by control.

  Hereinafter, means for solving the above-described problems and the operation and effects thereof will be described.

  According to a first aspect of the present invention, in a DC / DC converter that converts a DC input voltage into a DC voltage having a voltage value different from the DC voltage and outputs the DC / DC converter, the DC / DC converter includes: It comprises two or more DCDC converters, and comprises a spread spectrum means for operating the switching element according to a time series pattern including a plurality of different switching frequencies, the spread spectrum means for each of the DCDC converters, It is characterized by shifting the phase.

  In the said invention, it becomes possible to mutually make switching frequency used for operation of each DCDC converter differ by shifting the phase of a time-sequential pattern. For this reason, it becomes possible to suppress the noise level in a specific switching frequency and its harmonics.

The invention described in claim 1 is further characterized in that the plurality of switching frequencies in the time-series pattern do not have a harmonic component common to each other in a predetermined radio broadcast region.

  According to the said invention, the situation where the noise level of the specific frequency in a radio | wireless broadcast area | region becomes large especially can be avoided.

According to a second aspect of the present invention, in the first aspect of the present invention, the number of different switching frequencies is greater than the number of the DCDC converters.

  In the above invention, one switching period (one cycle of ON / OFF) may be adjacent to each other, and different switching frequencies may be used. For this reason, spectrum spreading can be suitably performed.

A third aspect of the invention is characterized in that, in the first or second aspect of the invention, the reciprocal of one period of the time series pattern is set equal to or higher than an audible frequency.

  In the above invention, even if each of the spread switching frequencies and their harmonics overlap with the frequency of the radio broadcast for which noise suppression is desired, the reciprocal of the time from the timing at which the overlap occurs to the timing at which the next overlap occurs is calculated. It can be above the audible frequency. For this reason, even when the wireless broadcast is received, it is possible to avoid the occurrence of noise in the audible area due to the overlap in the reproduced audio signal.

The invention according to claim 4 is the invention according to any one of claims 1 to 3 , wherein the spread spectrum means includes operation means for operating the switching element for each DCDC converter, and A correction signal output means is provided for outputting a correction signal for correcting the time change of the phase shift to each operation means.

  Due to individual differences between DCDC converters and the like, there is a possibility that a time change may occur in the phase shift while switching control according to the time series pattern is continued. In the above invention, in view of this point, such a situation can be dealt with by outputting a correction signal to each operation means.

According to a fifth aspect of the present invention, in the invention according to the fourth aspect , the correction signal output means outputs a time point designation signal for designating a time point on the time series pattern for the operation of the switching element to the operation means. It is a thing to do.

  In the above invention, it is possible to grasp at which point on the current time series pattern each operation means should be, so that the mutual amount of phase shift can be adjusted without mutual communication between the operation means. Can do.

According to a sixth aspect of the present invention, in the fourth aspect of the present invention, the correction signal output means outputs a signal for temporarily stopping the DCDC converter to be operated every time the DCDC converter is operated for a specified time, and thereafter operating. Is output to the operating means.

  In the above-described invention, the DCDC converter is temporarily stopped and then restarted, so that the time change of the phase shift due to the longer operating time can be corrected.

The invention according to claim 7 is the invention according to any one of claims 1 to 6 , wherein the spread spectrum means includes a storage means for storing information relating to the time series pattern, and an operation for operating the switching element. Means for each of the DCDC converters, and the information on the time series pattern stored in the storage means is information in which the phase at the start of each DCDC converter is different. To do.

  In the above invention, since the phase at the start of the information related to the time series pattern stored in the storage means is different for each DCDC converter, it is possible to cause a phase shift.

The invention according to an eighth aspect is the invention according to any one of the first to sixth aspects, wherein the spread spectrum means includes a storage means for storing information relating to the time series pattern, and an operation for operating the switching element. And a command signal output means for outputting a command signal for instructing the operation means to start operation of the switching element. The time stored in the storage means The information on the sequence pattern is information in which the phases at the start of the DCDC converters coincide with each other, and the command signal output means shifts the output timing of the command signal for instructing the start for each operation means. It is characterized by.

  In the above invention, by shifting the output timing of the command signal for instructing the start, the phase of the time series pattern can be suitably shifted even though the information stored in the respective storage means of the DCDC converter is the same. it can.

The invention according to a ninth aspect is the invention according to any one of the first to sixth aspects, wherein the spread spectrum means stores storage means for storing information relating to the time series pattern and an operation for operating the switching element. And a means for outputting information related to the time-series pattern to each storage means.

  In the said invention, the phase of the said time series patterns can be shifted for every DCDC converter by making the information output to a memory | storage means mutually differ.

1 is a system configuration diagram according to a first embodiment. FIG. The circuit diagram which shows the circuit structure of the converter unit concerning the embodiment. The figure which shows the spectrum spreading | diffusion aspect concerning the embodiment. The figure which shows the setting method of the spreading | diffusion switching frequency concerning the embodiment. The time chart which shows the spectrum spreading | diffusion aspect concerning 2nd Embodiment. The flowchart which shows the procedure of the correction process of the time change of the phase shift of the DCDC converter concerning 3rd Embodiment. The figure which shows the spreading | diffusion pattern concerning 4th Embodiment. The time chart which shows the correction method of the time change of the phase shift between the DCDC converter concerning the embodiment. The figure which shows the production | generation method of the phase shift of the DCDC converter concerning 5th Embodiment. The figure which shows the production | generation method of the phase shift of the DCDC converter concerning 6th Embodiment.

(First embodiment)
Hereinafter, a first embodiment in which a switching device according to the present invention is applied to a hybrid vehicle will be described with reference to the drawings.

  FIG. 1 shows a system configuration according to the present embodiment.

  As shown in the figure, the high voltage battery 10 constitutes an in-vehicle high voltage system insulated from the in-vehicle low voltage system, and has an output voltage of a predetermined high voltage (for example, several hundred volts or more). Converter units 20 a, 20 b and 20 c are connected in parallel to high voltage battery 10. That is, converter units 20a, 20b, and 20c are connected to the positive electrode and the negative electrode of high-voltage battery 10 through positive electrode line Lp and negative electrode line Lm, respectively.

  All of the converter units 20a, 20b, and 20c step down the voltage of the high voltage battery 10 and apply it to the low voltage battery 12 that constitutes the in-vehicle low voltage system. Specifically, each of the converter units 20a, 20b, and 20c has a pair of output terminals connected to the high potential side line Lh and the ground line Lg, and the high potential side line Lh is connected to the positive electrode of the low voltage battery 12. ing. Here, the low-voltage battery 12 serves as a power source for in-vehicle accessories, and particularly serves as a power source for the control device 14. The control device 14 is a control device that controls these output voltages by operating the converter units 20a, 20b, and 20c. Specifically, the control device 14 outputs command signals sa, sb, and sc for commanding start and stop of operation to the converter units 20a, 20b, and 20c via the signal lines Lsa, Lsb, and Lsc, respectively. The converter units 20a, 20b, and 20c are started and stopped.

  FIG. 2 shows a circuit configuration of converter units 20a, 20b, and 20c (in the figure, these are collectively referred to as converter unit 20).

  As illustrated, the converter units 20 a, 20 b, and 20 c include a DCDC converter 22. The DCDC converter 22 is an insulating step-down converter circuit. That is, it includes a transformer 22b, a primary circuit 22a connected to the positive line Lp and the negative line Lm, and a secondary circuit 22c connected to the high potential line Lh and the ground line Lg. A current sensor 24 is provided on an electrical path connected to the high potential side line Lh on the secondary side of the DCDC converter 22. A voltage sensor 26 is connected between the electrical paths connected to the high potential side line Lh and the ground line Lg. The detected value of the output current by the current sensor 24 and the detected value of the output voltage by the voltage sensor 26 are taken into the operation unit 28.

  The operation unit 28 operates and stops the DCDC converter 22 based on a command signal input via the signal line Ls (general notation of Lsa, Lsb, and Lsc). That is, based on the output current and output voltage, the operation signals g1 to g4 are output to the switching elements of the DCDC converter 22 so that the values are appropriate for feedback control of these. Here, the operation signal is a signal having an ON time ratio (time ratio) with respect to one cycle of ON / OFF as an operation amount for controlling the output current and the output voltage. In particular, the operation unit 28 stores a diffusion pattern for the switching frequency that is the reciprocal of the one cycle, and performs switching control by outputting an operation signal based on this.

  FIG. 3 shows a spread frequency pattern stored in the operation unit 28.

  As illustrated, the spread frequency pattern is a time-series pattern of six switching frequencies f1 to f6 that are different from each other. By performing switching control according to this pattern, switching according to each of the switching frequencies f1, f2, f3, f4, f5, and f6 is periodically performed. Here, in the present embodiment, the phases of the diffusion patterns stored in the operation units 28 of the converter units 20a, 20b, and 20c are different from each other. That is, any diffusion pattern is a pattern in which switching control is periodically performed in the order of f1 to f6, but the switching frequencies employed in the first switching control are different from each other. Is set to Thereby, in each of converter units 20a, 20b, and 20c, if switching control is simultaneously started according to these stored patterns, switching control according to the diffusion pattern is performed, but periodic switching control is not performed. The phases will be different from each other.

  As a result, the switching frequencies at the same timing are different between the converter units 20a, 20b, and 20c, so that the switching frequencies can be spread.

  Further, as shown in FIG. 4, the switching frequency is set so that the harmonics of each other do not coincide in the AM broadcast band. In this embodiment, the switching frequency is set to “hundreds to hundreds of kHz (hundreds of hundreds of kHz in the figure)”, and a setting in consideration of the fact that relatively lower harmonics overlap with the AM broadcast band. It is. By making the harmonics not coincide with each other, it is possible to avoid a particularly large noise at a specific broadcasting station frequency.

  According to the embodiment described in detail above, the following effects can be obtained.

  (1) The phases of the diffusion patterns stored in the operation units 28 of the converter units 20a, 20b, and 20c are made different from each other. Thereby, it becomes possible to suppress the noise level at a specific switching frequency and its harmonics.

  (2) A plurality of switching frequencies in the diffusion pattern are made not to have a common harmonic component in the AM broadcast region. As a result, it is possible to avoid a situation in which the noise level of a specific frequency in the AM broadcast area becomes particularly large.

  (3) The number of switching frequencies different from each other in the diffusion pattern is set to be twice or more the number of converter units 20a, 20b, 20c. As a result, it is possible to avoid the same switching frequency being used at the same time and the switching frequency being the same between adjacent switchings in time series.

  (4) A start / stop command is output from the control device 14 to each converter unit 20a, 20b, 20c. Thereby, even if it does not have a means which enables communication between converter units 20a, 20b, and 20c, a phase shift can be easily made between converter units 20a, 20b, and 20c.

(Second Embodiment)
Hereinafter, the second embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  FIG. 5 shows a diffusion pattern according to this embodiment. As illustrated, in this embodiment, the reciprocal number F of one period of the time-series pattern of the switching frequency that is periodically changed is set to be equal to or higher than the threshold frequency Fth corresponding to the audible frequency. Thereby, even if the harmonic of a specific switching frequency overlaps with a specific AM broadcast frequency region, the reciprocal of the time from when the overlap occurs until the next overlap can be made equal to or higher than the threshold frequency Fth. For this reason, by setting the threshold frequency Fth to a frequency that cannot be perceived by humans, it is possible to suitably avoid a situation in which noise that can be perceived by humans from speakers is generated when receiving AM broadcasts. Here, the threshold frequency Fth may be, for example, “20 kHz” or more. This is because the audible frequency is said to be “20 Hz to 20 kHz”. However, this setting is not absolute. Actually, there are individual differences in human hearing ability, and for example, human beings who can catch a sound wave of “20 kHz” are rare. For this reason, even if the spreading frequency is set to, for example, “15 kHz” or more, a remarkable effect can be obtained.

  According to such a setting, it is possible to suitably suppress or avoid noise that can be perceived by humans when receiving an AM broadcast, without setting so that the higher harmonics do not match within the AM broadcast area. However, from the viewpoint of avoiding a situation where noise in a specific frequency band is particularly large, it is effective to perform a setting in which high-order harmonics do not match.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects according to the above-described effects of the first embodiment.

  (5) The reciprocal of one cycle of the diffusion pattern was set to be higher than the audible frequency. Thereby, it is possible to avoid the occurrence of noise in the audible area in the reproduced audio signal when receiving the AM broadcast.

(Third embodiment)
Hereinafter, the third embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  When a plurality of converter units 20a, 20b, and 20c are used, there are usually individual differences. For this reason, there is a possibility that the time of one cycle of the diffusion pattern shown in FIG. 3 is slightly shifted for each converter unit 20a, 20b, 20c. In this case, the phase shift amount initially set by the pattern shown in FIG. 3 may change as switching control continues.

  Therefore, in the present embodiment, processing for correcting the temporal change of the phase shift is performed.

  FIG. 6 shows the procedure of the correction process of the time variation of the phase shift according to the present embodiment. This process is repeatedly executed by the control device 14 at a predetermined cycle, for example.

  In this series of processes, first, in step S10, it is determined whether or not it is immediately after the process of temporarily stopping converter units 20a, 20b, and 20c. If it is determined that it is immediately after execution, an activation command is output to converter units 20a, 20b, and 20c in step S12. Thereby, converter units 20a, 20b, and 20c perform switching control according to the diffusion pattern shown in FIG.

  When the process of step S12 is completed or when a negative determination is made in step S10, a time measuring process is performed in step S14 to measure the operating time after starting the converter units 20a, 20b, and 20c. In a succeeding step S16, it is determined whether or not the measured time is a predetermined time or more. This predetermined time is assumed to be due to the individual difference between the converter units 20a, 20b, and 20c, and the phase shift between the switching controls according to the diffusion pattern is shifted from the value shown in FIG. The time is set. Here, the specified value is a value smaller than the deviation at which the switching frequencies coincide with each other. If it is longer than the predetermined time, in step S18, the converter units 20a, 20b, and 20c are temporarily stopped. Thus, converter units 20a, 20b, and 20c are temporarily stopped regardless of whether or not electric power is supplied to in-vehicle auxiliary equipment such as low-voltage battery 12. In addition, when the process of step S18 is completed or when negative determination is made in step S16, this series of processes is once ended.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects according to the above-described effects of the first embodiment.

  (6) Each time the converter units 20a, 20b, 20c are operated for a predetermined time, a signal for temporarily stopping the converter units 20a, 20b, 20c is output to the converter units 20a, 20b, 20c, and then a signal for commanding the operation is converted to the converter units 20a, 20b, 20c. Output to. As a result, it is possible to correct the time change of the phase shift due to the longer operation time.

(Fourth embodiment)
Hereinafter, the fourth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the first embodiment, the phases of the diffusion patterns stored in the converter units 20a, 20b, and 20c are made different from each other. On the other hand, in this embodiment, as shown in FIG. 7, the phases of the diffusion patterns stored in the converter units 20a, 20b, and 20c are the same. And the phase of a spreading | diffusion pattern mutually shifts between converter units 20a, 20b, 20c by shifting the timing of the start command with respect to each of converter unit 20a, 20b, 20c.

  FIG. 8 shows a method for setting the phase of the diffusion pattern according to this embodiment. Specifically, FIG. 8A shows the transition of the command signal sa to the converter unit 20a, FIG. 8B shows the transition of the command signal sb to the converter unit 20b, and FIG. The transition of the command signal sc to the converter unit 20c is shown.

As shown in the figure, in this embodiment, after the start command is output to the converter unit 20b, the start command is output to the converter unit 20c when "1 / f1 + 1 / f2" has elapsed. After that, when “1 / f3 + 1 / f4” has elapsed, a start command is output to the converter unit 20a. Also by this, in each switching control of converter unit 20a, 20b, 20c, a mutual phase can be shifted in the aspect according to what was shown in previous FIG.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects according to the above-described effects of the first embodiment.

  (7) The output timing of the command signal for instructing the start is shifted with respect to each of the converter units 20a, 20b, and 20c. As a result, the phase of the time-series pattern can be suitably shifted regardless of whether the information stored in converter units 20a, 20b, and 20c is the same.

(Fifth embodiment)
Hereinafter, a fifth embodiment will be described with reference to the drawings, focusing on differences from the first embodiment.

  In the present embodiment, as shown in FIG. 9, the controller 14 has a function of outputting a time designation signal sn for designating a time point on the diffusion pattern to each of the converter units 20a, 20b, and 20c. Thus, for example, the converter unit 20a, 20b, 20c is simultaneously output to the converter unit 20a, 20b, 20c to indicate that it is the first switching time of the stored diffusion pattern, so that each of the converter units 20a, 20b, 20c It is possible to start switching from the beginning of the diffusion pattern shown in FIG. For this reason, even if a time change occurs in the phase shift between the diffusion patterns due to the continuation of the switching control due to the individual difference between the converter units 20a, 20b, and 20c, this can be corrected. Note that the output cycle of the time designation signal sn may be about a predetermined time in the process of step S16 of FIG.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects according to the above-described effects of the first embodiment.

  (8) The time designation signal sn for designating the time on the diffusion pattern is output to the converter units 20a, 20b, and 20c. As a result, the converter units 20a, 20b, and 20c can grasp at which point on the diffusion pattern they should be present, so that the converter units 20a, 20b, and 20c can communicate with each other without communicating directly with each other. The amount of deviation can be adjusted.

(Sixth embodiment)
Hereinafter, the sixth embodiment will be described with reference to the drawings with a focus on differences from the first embodiment.

  In the present embodiment, as shown in FIG. 10, the control device 14 has a function of outputting a signal sf on which information related to a diffusion pattern is superimposed to each of the converter units 20a, 20b, and 20c. Thereby, for example, by outputting the diffusion pattern shown in FIG. 3 to each of the converter units 20a, 20b, and 20c from the control device 14, the phase difference between the respective diffusion patterns of the converter units 20a, 20b, and 20c is obtained. Misalignment can occur. Further, for example, the converter unit 20a is newly output by outputting a new signal sf to initialize the diffusion pattern of the converter units 20a, 20b, and 20c at every elapse of a predetermined time in the process of step S16 of FIG. , 20b, 20c can be corrected for temporal changes in phase due to individual differences.

  According to the embodiment described above in detail, the following effects can be obtained in addition to the effects according to the above-described effects of the first embodiment.

  (9) Information related to the diffusion pattern is output from the control device 14 to each of the converter units 20a, 20b, and 20c. As a result, the phases of the diffusion patterns can be shifted for each of the converter units 20a, 20b, and 20c, and the temporal change of the phase shift can be corrected.

(Other embodiments)
Each of the above embodiments may be modified as follows.

  In each of the above embodiments, “all” high-order harmonics of the switching frequency are not matched with each other in the AM broadcast area, but this is not a limitation. For example, high-order harmonics of the same order may not match each other.

  In each of the above embodiments, all the high-order harmonics of the switching frequency are not “matched” with each other in the AM broadcast area, but this is not restrictive. For example, the interval between high-order harmonics may not be within the occupied frequency bandwidth of AM broadcasting.

  In each of the above embodiments, the high-order harmonics of the switching frequency are not matched with each other in the “AM broadcast area”, but the present invention is not limited to this. For example, the higher harmonics of the switching frequency may not match each other in the SW broadcast area.

  In the first embodiment, the phases of the time series patterns stored in the operation units 28 of the converter units 20a, 20b, and 20c are shifted from each other, and the drive start timing of the DCDC converter 22 is made simultaneous. However, it is not limited to this. For example, the drive start timings of the converter units 20a and 20b and the drive start timings of the converter units 20b and 20c may be separated from each other by one period (“1 / F”) of the time series pattern.

  In the second embodiment, the pattern frequency F, which is the reciprocal of one period of the time-series pattern, is set to the upper limit value of the audible frequency or more. However, the present invention is not limited to this and is not more than the lower limit value of the audible frequency (for example, “20 Hz” or less). It is good.

  In each of the above-described embodiments, the timing of the rising edge of the switching signal is synchronized between the converter units 20a, 20b, and 20c once in one cycle of the diffusion pattern. However, the present invention is not limited to this. For example, in the first embodiment, the start-up command to each of the converter units 20a, 20b, and 20c is output at a timing shifted from each other within a time equal to or less than the minimum value of the switching frequency, thereby spreading the rising edge timing. All of the patterns in one cycle may not match.

  The number of switching frequencies spread by spread spectrum is not limited to those exemplified in the above embodiments. In short, it is sufficient if it is larger than the number of DCDC converters 22. However, at this time, it is desirable that all the switching frequencies used in adjacent ones in the switching period (one cycle of ON / OFF) are not equal. Further, as in each of the above embodiments, it is preferable that there is no common switching frequency used in one switching period, and that the switching frequencies used between adjacent ones are all different. desirable. In order to satisfy these, the number of spread switching frequencies may be two times or more the number of DCDC converters 22.

  In each of the above embodiments, each of the plurality of DCDC converters 22 includes the operation unit 28 for operating the DCDC converter 22, but the present invention is not limited thereto. For example, the control device 14 may be configured to include an operation unit that collectively operates all the DCDC converters 22.

  The circuit configuration of the DCDC converter 22 is not limited to that illustrated in FIG. 2 and the like, and may be a partial resonance type converter illustrated in, for example, Japanese Patent Application Laid-Open No. 5-276651. Further, the DCDC converter 22 is not limited to a step-down converter. The means for detecting the output current of the DCDC converter 22 is not limited to the current sensor 24, and may be means for converting the detected value of the current flowing through the primary side into the secondary side current.

  The number of converter units 20 is not limited to “3”, and may be “2” or “4” or more.

  DESCRIPTION OF SYMBOLS 10 ... High voltage battery, 14 ... Control apparatus, 20a, 20b, 20c ... Converter unit, 22 ... DCDC converter, 28 ... Operation part.

Claims (9)

For a DCDC converter that converts a DC input voltage into a DC voltage having a different voltage value and outputs the DC voltage, a switching device that operates a switching element included in the DCDC converter,
The DCDC converter comprises two or more DCDC converters;
Spread spectrum means for operating the switching element according to a time-series pattern including a plurality of different switching frequencies,
The spread spectrum means shifts the phase of the time series pattern for each DCDC converter ,
The switching device according to claim 1, wherein the plurality of switching frequencies in the time series pattern do not have a harmonic component common to each other in a predetermined radio broadcast region . The number of the switching frequency where the mutually different, the switching device according to claim 1, characterized in that more than the number of the DCDC converter. 3. The switching device according to claim 1, wherein the reciprocal of one period of the time-series pattern is set to an audible frequency or more. The spread spectrum means includes an operation means for operating the switching element for each DCDC converter, and a correction signal output means for outputting a correction signal for correcting a time change of the phase shift to the operation means. The switching device according to any one of claims 1 to 3 , further comprising: 5. The switching device according to claim 4, wherein the correction signal output means outputs a time designation signal for designating a time on the time series pattern for operation of the switching element to the operation means. . The correction signal output means outputs a signal for temporarily stopping the DCDC converter every time the DCDC converter is operated for a specified time to the operation means, and thereafter outputs a signal for commanding the operation to the operation means. The switching device according to claim 4, wherein The spread spectrum means includes a storage means for storing information related to the time series pattern, and an operation means for operating the switching element for each DCDC converter,
Information regarding the time-series pattern stored in said storage means, said each DCDC converter according to any one of claims 1 to 6, characterized in that the starting phase is information different Switching device. The spread spectrum means includes storage means for storing information related to the time series pattern and operation means for operating the switching element for each DCDC converter, and the operation means operates the switching element. Command signal output means for outputting a command signal for commanding the start of
The information on the time series pattern stored in the storage means is information in which the phases at the start of the DCDC converters coincide with each other,
The command signal output means for each of said operating means, the switching device according to any one of claims 1 to 6, wherein the shifting the output timing of the command signal for commanding the start. The spread spectrum means includes storage means for storing information related to the time series pattern and operation means for operating the switching element for each of the DCDC converters, and the time series pattern is stored in each storage means. further comprising means for outputting information about the switching apparatus according to any one of claims 1 to 6, wherein.

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