control device
The control device addresses the challenge of detecting short circuits in multi-phase power supplies by using a short-circuit detection unit that counts ON cycles and derivative analysis, ensuring timely fault detection and system reliability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- DENSO CORP
- Filing Date
- 2024-12-23
- Publication Date
- 2026-07-03
Smart Images
Figure 2026111338000001_ABST
Abstract
Description
Technical Field
[0006] , ,
[0001] The disclosure in this specification relates to a control device.
Background Art
[0002] Patent Document 1 discloses a control circuit of a DC / DC converter. The description of the prior art document is incorporated herein by reference as an explanation of the technical elements in this specification.
Prior Art Document
Patent Document
[0003] < A short-circuit detection unit (43) detects a short circuit between the inductors of the coupled inductor based on the switching period of the drive unit and the current value detected by the current detection unit, Equipped with, The short-circuit detection unit determines that a short circuit has occurred between inductors in a phase that includes a given phase if the derivative of the current value corresponding to a given phase is positive and greater than or equal to a threshold value during the off-period of the drive unit in that phase.
[0007] According to the disclosed control device, if a short circuit occurs between an inductor in any phase and an inductor in another phase, the derivative value corresponding to the arbitrary phase becomes positive and above a threshold even when the drive unit of the other phase is turned on. The short-circuit detection unit determines that a short circuit has occurred between inductors in phases including the arbitrary phase if the derivative value corresponding to the arbitrary phase becomes positive and above a threshold during the off period of the drive unit in the arbitrary phase. Therefore, a short circuit between coupled inductors can be detected.
[0008] The various embodiments disclosed in this specification employ different technical means to achieve their respective objectives. The reference numerals in parentheses in the claims are illustrative in their correspondence with the embodiments described later and are not intended to limit the technical scope. The objectives, features, and effects disclosed in this specification will become clearer by referring to the subsequent detailed description and the accompanying drawings. [Brief explanation of the drawing]
[0009] [Figure 1] This is a diagram showing a control device according to the first embodiment. [Figure 2] This is a circuit diagram showing a multiphase power supply. [Figure 3] This is a perspective view showing a coupled inductor. [Figure 4] This is a perspective view showing the core. [Figure 5] This is a perspective view showing a coil. [Figure 6] It is a diagram showing an example of a short circuit between inductors. [Figure 7] It is a diagram showing the PWM waveform and Vout1 waveform of each phase. [Figure 8] It is a block diagram showing a short circuit detection unit. [Figure 9] It is a flowchart showing the process executed by the short circuit detection unit. [Figure 10] It is a timing chart showing various signal waveforms in a state where no short circuit between inductors occurs. [Figure 11] It is a timing chart showing various signal waveforms in a state where a short circuit between inductors occurs. [Figure 12] It is a block diagram showing a modified example of the short circuit detection unit. [Figure 13] It is a diagram showing a control device according to the second embodiment. [Figure 14] In the control device according to the third embodiment, it is a flowchart showing the process executed by the short circuit detection unit. [Figure 15] It is a diagram showing a control device according to the fourth embodiment. [Figure 16] It is a diagram showing a modified example of the control device. [Figure 17] It is a diagram showing a modified example of the control device. [Figure 18] In the reference example, it is a diagram showing the Iout waveform and Vout1 waveform during normal operation. [Figure 19] In the reference example, it is a diagram showing the Iout waveform and Vout1 waveform when a short circuit between inductors occurs. [Figure 20] In the control device according to the fifth embodiment, it is a flowchart showing the process executed by the processor. [Figure 21] It is a flowchart showing a modified example.
Embodiments for Carrying Out the Invention
[0010] Hereinafter, a plurality of embodiments will be described based on the drawings. In each embodiment, the same reference numerals may be assigned to corresponding components, and redundant descriptions may be omitted. When only a part of the configuration is described in each embodiment, the configuration of other embodiments described previously can be applied to the other parts of the said configuration. Also, not only the combinations of configurations explicitly shown in the description of each embodiment, but also the configurations of a plurality of embodiments can be partially combined with each other as long as there is no problem with the combination, even if not explicitly stated.
[0011] (First Embodiment) As will be described later, the control device according to this embodiment includes at least a power control unit that controls a multi-phase power supply having a coupled inductor. A control device having only a power control unit is a control device for a multi-phase power supply. The control device may include a multi-phase power supply in addition to the power control unit. The control device may include a load that operates by receiving power supply from the multi-phase power supply in addition to the power control unit and the multi-phase power supply. The load may include a processor. A control device including a power control unit, a multi-phase power supply, and a processor may be referred to as an ECU. ECU is an abbreviation for Electronic Control Unit.
[0012] The ECU can be applied to, for example, a moving body. The moving body includes vehicles such as engine-driven vehicles, hybrid vehicles, motor-driven vehicles, drones, flying bodies such as eVTOLs, ships, construction machines, and agricultural machines. eVTOL is an abbreviation for electronic Vertical Take-Off and Landing aircraft. For example, when applied to a vehicle, the ECU controls the devices mounted on the vehicle.
[0013] <Control Device> Figure 1 shows an example of a control device according to this embodiment. The example control device 10 is an ECU mounted in a vehicle. The control device (ECU) 10 may be, for example, an autonomous driving ECU, or an ADAS ECU that performs control to assist the driver's driving operations. ADAS is an abbreviation for Advanced Driving Assistant System. For example, levels 3 to 5 as defined by the Society of Automotive Engineers (SAE International) correspond to autonomous driving levels, and levels 1 to 2 correspond to driving assistance levels. The control device 10 may also be an infotainment system ECU or a cockpit ECU. A cockpit ECU is an ECU that controls the meter system, navigation system, air conditioning system, etc. The control device 10 may also be, for example, an integrated ECU that integrates multiple control functions.
[0014] The control device 10 comprises a multiphase power supply 20, a processor 30, and a power control unit 40. The control device 10 may also include a load separate from the processor 30.
[0015] <Multiphase power supply> Figure 2 is a circuit diagram showing a multiphase power supply. For convenience, some drivers are simplified in Figure 2. The multiphase power supply 20 is a power supply circuit provided within the control device 10. The multiphase power supply 20 steps down the input voltage to a predetermined voltage that can be supplied to a load such as the processor 30 and outputs it. The multiphase power supply 20 is a step-down DC-DC converter. The multiphase power supply 20 steps down the input voltage Vin to a predetermined voltage (for example, around 1V) and outputs it as the output voltage Vout to the processor 30 load.
[0016] The control device 10 may include a primary power supply circuit (not shown) that forms a power supply circuit together with the multiphase power supply 20. The primary power supply circuit is configured to step down the input voltage to a predetermined voltage and output it. The primary power supply circuit is a step-down DC-DC converter. The primary power supply circuit generates a constant voltage (e.g., 5V) lower than the power supply voltage (+B) based on a power supply from, for example, a battery mounted on the vehicle. In a configuration that includes a primary power supply circuit, the multiphase power supply 20 is a secondary power supply circuit that uses the voltage generated by the primary power supply circuit as its input voltage Vin.
[0017] As shown in Figures 1 and 2, the multiphase power supply 20 comprises multiple drive units (DRs) 21, a coupled inductor 22C having multiple inductors 22, and a capacitor 23. The multiphase power supply 20 has multiple phases, each including a drive unit 21 and an inductor 22. Phases are sometimes referred to as stages or channels. The number of phases is not particularly limited. The example multiphase power supply 20 has three phases. In Figure 2, the three phases are shown as Phase 1, Phase 2, and Phase 3. In Figure 1, the numbers appended to the end of the DRs indicate which phase they constitute. For example, DR1 is a drive unit 21 that constitutes Phase 1.
[0018] The illustrated drive unit 21 includes MOSFETs 21H and 21L. MOSFET is an abbreviation for Metal Oxide Semiconductor Field Effect Transistor. Other switching elements such as IGBTs may be used instead of MOSFETs 21H and 21L. IGBT is an abbreviation for Insulated Gate Bipolar Transistor. MOSFETs 21H and 21L are connected in series between the power supply line to which the input voltage Vin is input and the ground (GND) line, with MOSFET 21H on the high side and MOSFET 21L on the low side. In Figures 1 and 2, the high-side MOSFET 21H is shown as MOSH, and the low-side MOSFET 21L is shown as MOSL. The illustrated drive unit 21 has a drive circuit (not shown) that turns MOSFETs 21H and 21L on and off based on a PWM signal, which will be described later.
[0019] One end of the inductor 22 is connected to the connection point (node) of MOSFETs 21H and 21L. The other end of the inductor 22 is connected to the output line. The inductor 22 is provided individually for each drive unit 21. The drive unit 21 and inductor 22 of each phase are connected in parallel to each other. Parallelization allows for an increase in the output current from the multiphase power supply 20, i.e., the load current.
[0020] Capacitor 23 is connected to the output line. The positive terminal of capacitor 23 is connected to the output line. The negative terminal of capacitor 23 is connected to ground. Capacitor 23 may be provided individually for each phase, or it may be provided in common for multiple phases. In the example multi-phase power supply 20, capacitor 23 is provided for each phase.
[0021] Figure 3 is a perspective view showing an example of a coupled inductor. Figure 4 is a perspective view showing the core. Figure 5 is a perspective view showing the coil. One coupled inductor 22C provides multiple inductors 22 that constitute a multiphase power supply 20.
[0022] In the following, the direction in which multiple coils are aligned is referred to as the X direction. The direction in which two end cores are aligned, which is one direction perpendicular to the X direction, is referred to as the Y direction. The direction perpendicular to both the X and Y directions is referred to as the Z direction. Unless otherwise specified, the shape viewed from the Z direction, in other words, the shape along the XY plane defined by the X and Y directions, is referred to as the planar shape. The view from the Z direction is sometimes simply referred to as the planar view.
[0023] As shown in Figures 3 to 5, the coupled inductor 22C comprises a core 24 and multiple coils 25. Each coil 25 constitutes an inductor 22. The multiple coils 25 are arranged on a single core 24, that is, a common core 24, and are magnetically coupled to one another. By using the coupled inductor 22C, the magnetic flux between phases cancels each other out, making it possible to reduce the effective inductance.
[0024] The core 24 is formed using a magnetic material such as ferrite. The core 24 functions as a magnetic circuit. The core 24 has a plurality of core cores 241 and end cores 242, 243. The core 24 may be made of a single component or a combination of multiple components. The core 24 has a coil 25 inserted through it. The core cores 241 are provided individually for the coil 25. The coil 25 is wound around the core cores 241. The core cores 241 extend in the Y direction. The plurality of core cores 241 are arranged in the X direction with a predetermined interval. The example core 24 has three core cores 241. Each core core 241 is substantially rectangular parallelepiped in shape. The three core cores 241 have the same shape as each other.
[0025] The end cores 242 and 243 are positioned opposite each other in the Y direction. The end cores 242 and 243 have a core core 241 in between them. The end cores 242 and 243 extend in the X direction, which is the direction in which the multiple core cores 241 are aligned. One end of the multiple core cores 241 is connected to end core 242, and the other end of the multiple core cores 241 is connected to end core 243. The end cores 242 and 243 magnetically connect the multiple core cores 241. The example end cores 242 and 243 have the same shape as each other. The end cores 242 and 243 are approximately rectangular parallelepipeds with the X direction as their longitudinal direction.
[0026] The coil 25 is formed using a metal material with good conductivity, such as copper. The coil 25 is formed by processing a metal sheet, not a metal wire. The metal sheet is sometimes referred to as a metal frame. Multiple coils 25 are formed from the same material and have the same shape. Multiple coils 25 have approximately equal inductance. Multiple coils 25 are arranged in the X direction with a predetermined spacing. Multiple coils 25 are arranged in the same orientation. The coils 25 are fixed to the core 24, for example, by adhesive. By bringing adjacent coils 25 closer together, the magnetic flux cancellation effect can be increased. In other words, the effective inductance reduction effect can be increased.
[0027] The coil 25 is formed by bending a metal plate material having a predetermined thickness. The coil 25 has a main body portion 251 and terminal portions 252 and 253. The terminal portions 252 and 253 are external connection terminals in the coil 25 and are soldered to, for example, lands on a substrate (not shown). The thickness direction of the terminal portions 252 and 253 is substantially parallel to the Z direction. One of the plate surfaces of the terminal portion 252, the upper surface, faces the lower surface of the end core 242. The upper surface of the terminal portion 253 faces the lower surface of the end core 243.
[0028] The illustrated terminal portions 252 and 253 have a substantially rectangular shape in plan view. Terminal portion 252 is connected to the lower wall 2511 of the main body portion 251 and extends in the Y direction. Terminal portion 253 is connected to the lower wall 2512 of the main body portion 251 and extends in the Y direction, but in the opposite direction to terminal portion 252. Terminal portions 252 and 253 connected to the same main body portion 251 are offset in the Y direction. Terminal portions 252 and 253 connected to the same main body portion 251 are offset in the X direction. Terminal portion 252 has approximately the same length as the end core 242 in the Y direction. Terminal portion 253 has approximately the same length as the end core 243 in the Y direction. Terminal portions 252 and 253 may extend outward beyond the corresponding end cores 242 and 243 in plan view.
[0029] The main body portion 251 is the part wrapped around the core portion 241. In a plan view, the main body portion 251 is the part that overlaps with the core portion 241. The main body portion 251 has lower walls 2511, 2512, side walls 2513, 2514, and an upper wall 2515.
[0030] The thickness direction of the lower walls 2511 and 2512 is approximately parallel to the Z direction. One of the upper surfaces of the lower walls 2511 and 2512 faces the lower surface of the core 241. The example lower walls 2511 and 2512 have a roughly rectangular shape in plan. Terminal portions 252 are attached to the Y-direction end of the lower wall 2511. The lower wall 2511 and terminal portions 252 extend along the Y direction. Terminal portions 253 are attached to the Y-direction end of the lower wall 2512. The lower wall 2512 and terminal portions 253 extend along the Y direction. The lower walls 2511 and 2512 have approximately the same length as the core 241 in the Y direction. The lower walls 2511 and 2512 in one main body portion 251 are arranged in the X direction with a predetermined interval between them.
[0031] The side wall 2513 is connected to the bottom wall 2511. The side wall 2513 extends from the bottom wall 2511 in the Z direction. The side wall 2513 faces one of the sides of the core 241. The illustrated side wall 2513 is substantially rectangular in a plan view in the X direction. The side wall 2513 has approximately the same length as the bottom wall 2511 in the Y direction. The side wall 2513 is bent at an angle of approximately 90 degrees to the bottom wall 2511. The thickness direction of the side wall 2513 is substantially parallel to the X direction. The lower end of the side wall 2513 is connected to the end of the bottom wall 2511 opposite to the end facing the bottom wall 2512.
[0032] Similarly, the side wall 2514 is connected to the bottom wall 2512. The side wall 2514 extends from the bottom wall 2512 in the Z direction. The side wall 2514 faces the side of the core 241 opposite to the side that the side wall 2513 faces. The example side wall 2514 is substantially rectangular in plan view in the X direction. The side wall 2514 has approximately the same length as the bottom wall 2512 in the Y direction. The side wall 2514 is bent at an angle of approximately 90 degrees to the bottom wall 2512. The thickness direction of the side wall 2514 is substantially parallel to the X direction. The lower end of the side wall 2514 is connected to the end of the bottom wall 2512 opposite to the end facing the bottom wall 2511.
[0033] The upper wall 2515 bridges the side walls 2513 and 2514. The upper wall 2515 extends in the X direction. One end of the upper wall 2515 connects to the upper end of the side wall 2513, and the other end connects to the upper end of the side wall 2514. The upper wall 2515 has the same length as the side walls 2513 and 2514 in the Y direction. In plan view, the upper wall 2515 encompasses the entire areas of the side walls 2513 and 2514, and the lower walls 2511 and 2512.
[0034] The lower walls 2511, 2512, the side walls 2513, 2514, and the upper wall 2515 surround the core 241. The lower walls 2511, 2512, the side walls 2513, 2514, and the upper wall 2515 are attached to and wound around the core 241. End cores 242, 243 are positioned on terminal portions 252, 253. In adjacent coils 25, one side wall 2513 of coil 25 faces the other side wall 2514 of coil 25.
[0035] The coupled inductor 22C may include a cover in addition to the core 24 and the plurality of coils 25. The cover is positioned on the upper surface of the core 24 so as to cover the core 24 and the plurality of coils 25. The cover is used, for example, to suppress the adhesion of foreign matter to the coupled inductor 22C. The cover is used, for example, to suppress short circuits between the coils 25 due to conductive foreign matter. The cover is used, for example, to improve the suction during transport when mounting the coupled inductor 22C to a substrate. The material of the cover is not particularly limited as long as it can achieve the above objectives. For example, it may be a resin or a magnetic material.
[0036] <Processor> A processor (PU) 30 is an example of a load that operates by receiving power from a multi-phase power supply 20. A processor 30 can be, for example, a CPU or a GPU. CPU is an abbreviation for Central Processing Unit. GPU is an abbreviation for Graphics Processing Unit. The control device 10 may have only one processor 30, or it may have multiple processors 30. The control device 10 may have multiple types of processors 30. The processor 30 may be provided as an SoC or SiP. An SoC is a single semiconductor chip on which multiple components necessary to realize the functions of a system or device are implemented. SoC is an abbreviation for System On Chip. SiP is an abbreviation for System in Package.
[0037] The processor 30 executes predetermined control processes by running a control program stored in memory (not shown). Memory is a non-transitory tangible storage medium that non-temporarily stores programs and data that can be read by a computer.
[0038] The core voltage of the processor 30 is around 1V (for example, less than 1V), and the load current is several tens of amperes or more (for example, 100A or more). To handle such low voltage and high current, the control device 10 is equipped with a multi-phase power supply 20 as a power supply circuit. The multi-phase power supply 20 steps down the input voltage to a voltage corresponding to the core voltage of the processor 30 and outputs it. By using the multi-phase power supply 20, it is possible to handle the increased performance of the processor 30 accompanying improvements in autonomous driving levels and advancements in infotainment functions, and in particular, to handle autonomous driving levels 3 and above.
[0039] In a high-performance processor 30, the current consumption fluctuates rapidly depending on the calculation process, requiring many capacitors 23 to supply a stable voltage even during sudden load changes. Using a coupled inductor 22C allows for a smaller effective inductance value, as described above, thus improving responsiveness during sudden load changes. This significantly reduces the number of capacitors 23 compared to a configuration using a normal single inductor. For example, the size of the multiphase power supply 20, and consequently the control device 10, can be reduced.
[0040] <Power Control Unit> The power control unit 40 controls the multiphase power supply 20. As shown in Figure 1, the power control unit 40 includes a PWM control unit (PWMCU) 41.
[0041] The PWM control unit 41 outputs a control signal to the drive unit 21 to control the on / off state of the drive unit 21. The power supply control unit 40 performs voltage mode control, for example, by feedback of the output voltage Vout, to control the operation of the drive unit 21, i.e., the operation of MOSFETs 21H and 21L. The power supply control unit 40 determines the pulse width (duty cycle) of the PWM signal, which is the control signal, based on the output voltage Vout, and controls the output voltage Vout of the multiphase power supply 20. The power supply control unit 40 may perform current mode control instead of voltage mode control. In Figure 1, the PWM signal is shown as PWM. The number appended to the end of PWM indicates which phase it corresponds to.
[0042] The power control unit 40 synchronously controls the multiple drive units 21 so that they switch in different phases from each other. By using multiple phases in this way, the switching frequency can be artificially increased even if the switching frequencies of the multiple drive units 21 are the same. This makes it possible to reduce the ripple component of the output voltage Vout and improve responsiveness. The power control unit 40 switches the number of drive units 21 that are switched, i.e., the number of drive phases, according to the load current. The power control unit 40 compares the load current with the threshold current and increases and / or decreases the number of drive phases according to the comparison result.
[0043] The power control unit 40 detects short circuits occurring between the inductors 22, i.e., between the coils 25, of the coupling inductor 22C that constitutes the multiphase power supply 20. The power control unit 40 includes a current detection unit (CD) 42 and a short circuit detection unit (SD) 43. In Figure 1, the numbers appended to the end of CD and SD indicate which phase they correspond to. For example, CD1 is a current detection unit 42 that detects the current flowing through the drive unit (DR1) 21 in Phase 1. SD1 is a short circuit detection unit 43 that acquires a current detection signal from the current detection unit 42 (CD1) corresponding to Phase 1.
[0044] The current detection unit 42 detects the current flowing through the drive unit 21. The current detection unit 42 detects the current flowing through each of the drive units 21. In the example, the current detection unit 42 is provided individually for each drive unit 21. The means for current detection are not particularly limited. The current detection unit 42 may be provided integrally with the drive unit 21 or separately from the drive unit 21. The current detection unit 42 is, for example, a current sense provided on the same semiconductor chip as the MOSFETs 21H and 21L that constitute the drive unit 21. The current detection unit 42 detects the current flowing through the drive unit 21 of the corresponding phase and outputs a current detection signal (CDS) to the corresponding short-circuit detection unit 43. The number appended to the end of the CDS indicates which phase it corresponds to.
[0045] The short-circuit detection unit 43 detects a short circuit between the coupled inductors 22C based on the switching period of the drive unit 21 and the current value (current detection signal) detected by the current detection unit 42. Details of the short-circuit detection unit will be described later.
[0046] <Short circuit between inductors> Figure 6 shows an example of a short circuit between inductors. As described above, in the coupled inductor 22C, multiple coils 25, that is, multiple inductors 22, are arranged in a predetermined direction (X direction). In addition, in order to strengthen the magnetic coupling and reduce the effective inductance, the space between adjacent coils 25 is made very narrow. Therefore, there is a risk of a short circuit occurring between adjacent inductors due to the inclusion of conductive foreign matter, ion migration, etc.
[0047] In Figure 6, a short circuit occurs between the Phase 1 inductor 22 and the Phase 2 inductor 22 of the three-phase system. Vout1 shown in Figure 6 is the output voltage of Phase 1.
[0048] Figure 7 shows the PWM waveform and Vout1 waveform for each phase. In Figure 7, the on period for a predetermined duty cycle is shown in a simplified manner. The PWM waveform shows the on and off periods, that is, it shows the switching period. Of the output voltage Vout1, the dashed line shows the waveform under normal conditions, and the solid line shows the waveform during a short circuit. The solid line shows the waveform when a short circuit occurs between the inductors of Phase 1 and Phase 2, as shown in Figure 6. The dashed line for the output voltage Vout1 shows the overvoltage detection threshold and the undervoltage detection threshold. The range between the undervoltage detection threshold and the overvoltage detection threshold is the operating range.
[0049] Under normal conditions, the output voltage Vout1 rises significantly during the on-period of Phase 1. Due to the influence of magnetic coupling, the output voltage Vout1 also rises during the on-periods of Phase 2 and Phase 3. The rise during the on-periods of Phase 2 and Phase 3 is smaller than the rise during the on-period of Phase 1.
[0050] When a short circuit occurs between inductors, the output voltage Vout1 rises significantly during the on-periods of Phase 1 and Phase 2. Due to magnetic coupling, the output voltage Vout1 also rises during the on-period of Phase 3. The rise during the on-period of Phase 3 is smaller than the rises during the on-periods of Phase 1 and Phase 2. The ripple fluctuation is approximately doubled due to the short circuit between inductors, but it rarely reaches the overvoltage detection threshold. In other words, the overvoltage and undervoltage detection thresholds used in general fault diagnosis cannot detect a short circuit between inductors.
[0051] <Short circuit detection unit> The power control unit 40 illustrated in Figure 1 includes a plurality of short-circuit detection units 43. The illustrated short-circuit detection units 43 are provided individually for each phase. The power control unit 40 includes three short-circuit detection units 43.
[0052] Figure 8 is a block diagram of the short circuit detection unit. Figure 8 illustrates one of several short circuit detection units. The multiple short circuit detection units 43 have similar configurations to each other. The short circuit detection unit 43 detects inter-inductor short circuits in the coupled inductor 22C as described above. At least part of the functions of the short circuit detection unit 43 may be implemented in hardware, or at least part of the functions may be implemented in software. The short circuit detection unit 43 may include, for example, an analog circuit or a digital circuit. The short circuit detection unit 43 comprises an A / D converter (ADC) 431, a differential arithmetic unit (DC) 432, an ON count counter (OC) 433, a rising edge detection unit (RD) 434, a delay unit (DP) 435, and a comparator (CMP2) 436.
[0053] The A / D converter 431 acquires the current value detected by the current detection unit 42 of the corresponding phase, i.e., the current detection signal (CDS), and converts it into a digital signal. The A / D converter 431 outputs the current value converted into a digital signal to the differential arithmetic unit 432.
[0054] The differential arithmetic unit 432 performs a differential operation on the output of the A / D converter 431, i.e., the current value. The differential arithmetic unit 432 outputs the calculation result to the ON count counter 433. The rising edge detection unit 434 acquires the PWM signal of the corresponding phase and detects the rising edge of the ON timing. The delay unit 435 delays the rising edge timing detected by the rising edge detection unit 434 by a predetermined time and outputs it to the ON count counter 433.
[0055] The ON count counter 433 counts how many times within the switching cycle the current slope corresponding to when the drive unit 21 of the corresponding phase is turned ON occurs, based on the calculation result of the differential arithmetic unit 432. The ON count counter 433 resets the count based on the rising edge of the PWM signal acquired through the rising edge detection unit 434 and the delay unit 435. The ON count counter 433 resets the count at the start timing of the next switching cycle.
[0056] Under normal conditions where no short circuits occur between inductors, the ON count counter 433 counts only when the corresponding phase's drive unit 21 is turned ON. Therefore, the ON count counter 433 counts 1. On the other hand, if a short circuit occurs between inductors, i.e., between coils, the ON count counter 433 counts when the corresponding phase's drive unit 21 is turned ON and when the drive unit 21 to the shorted location is turned ON. Therefore, the ON count counter 433 counts 2. Furthermore, if there are multiple short circuits, the count increases by the number of short circuits.
[0057] The comparator 436 is located at the final stage of the short-circuit detection unit 43. The comparator 436 compares the count of the ON count counter 433 with the ON count threshold THn and outputs the comparison result. In the example comparator 436, the ON count threshold THn is 2. If the count is greater than or equal to the ON count threshold THn, the comparator 436 turns on the fault notification. The comparator 436 outputs the fault notification (SN) to the processor 30. Turning on the fault notification indicates that a short circuit has occurred between the inductors. If the count is less than the ON count threshold THn, the comparator 436 turns off the fault notification. Turning off the fault notification indicates that there is no short circuit between the inductors and the system is functioning normally. The comparator 436 obtains the rising edge timing of the PWM signal from the rising edge detection unit 434 and, at the start timing of the next switching cycle, determines whether there was a short circuit between the inductors in the previous switching cycle.
[0058] Figure 9 is a flowchart showing an example of the process performed by the short-circuit detection unit, specifically the short-circuit detection process. The short-circuit detection unit 43 performs the short-circuit detection process, for example, when power is supplied and it starts up.
[0059] The short circuit detection unit 43 first resets the ON count counter 433 (step S10). In the example, the short circuit detection unit 43 resets the ON count counter 433 to zero (0).
[0060] Next, the short-circuit detection unit 43 performs A / D conversion of the current detection signal (step S20). The A / D converter 431 acquires the current detection signal of the corresponding phase from the corresponding current detection unit 42 and performs A / D conversion.
[0061] Next, the short-circuit detection unit 43 performs a differential calculation of the current value (step S30). The differential calculator 432 performs a differential calculation of the current value output from the A / D converter 431. The differential value obtained by the calculation corresponds to the slope of the current.
[0062] As shown in the timing chart described later, the derivative (slope) becomes positive when the PWM signal is turned on, and negative when the PWM signal is off. Next, the short circuit detection unit 43 determines whether the sign of the derivative has changed from negative to positive (step S40), and if it has changed to positive, it determines whether the derivative is greater than or equal to the threshold THd (step S50). The ON count counter 433 determines whether the current slope corresponds to the ON state of the corresponding drive unit 21 at the timing when the sign of the derivative switches from negative to positive.
[0063] If the derivative value is greater than or equal to the threshold THd, the short circuit detection unit 43 then increments the count of the ON count counter 433 by 1 (step S60). The ON count counter 433 increments the ON count when the derivative value (slope) changes from negative to positive and the derivative value is greater than or equal to the threshold THd. If there is no change from negative to positive in the derivative value in step S40, the short circuit detection unit 43 returns to step S20 and executes the processing from step S20 onwards again. Similarly, if the derivative value is less than the threshold THd in step S50, the short circuit detection unit 43 executes the processing from step S20 onwards again.
[0064] Next, the short-circuit detection unit 43 determines whether or not it is the rising edge timing of the corresponding PWM signal (step S70). The comparator 436 obtains the rising edge timing of the PWM signal from the rising edge detection unit 434 and determines whether or not it is the start timing of the next switching cycle. If it is not the rising edge timing, the short-circuit detection unit 43 repeats the processing from step S20 onwards.
[0065] At the rising time, that is, the start time of the next switching cycle, the short-circuit detection unit 43 then determines whether the number of ONs is equal to or greater than the ON count threshold THn (step S80). If it is equal to or greater than the ON count threshold THn, the fault notification is turned ON (step S90). If it is less than the ON count threshold THn, the fault notification is turned OFF (step S100).
[0066] The example comparator 436 determines whether the number of ON counts obtained from the ON count counter 433 is 2 or greater, which is the ON count threshold THn. The comparator 436 turns on the fault notification if the ON count is 2 or greater, and turns off the fault notification if the ON count is less than 2. For example, the comparator 436 outputs an H-level signal corresponding to the fault notification if the ON count is 2 or greater, and outputs an L-level signal if the ON count is less than 2.
[0067] Next, the short circuit detection unit 43 determines whether its power supply is off or not (step S110). If the power supply is off, the short circuit detection process ends. If the power supply is not off, the short circuit detection unit 43 executes the process from step S10 onwards again. Since one cycle of the switching cycle has ended, the ON count counter is reset in step S10.
[0068] Figure 10 is a timing chart showing an example of various signal waveforms when no short circuit occurs between inductors. Figure 11 is a timing chart showing an example of various signal waveforms when no short circuit occurs between inductors. Figures 10 and 11 show the PWM waveform for each phase and the output waveform of the elements of the short detection unit 43 corresponding to Phase 1. Specifically, in the short detection unit (SD1) 43 corresponding to Phase 1, the current of the drive unit (DR1) 21, which is the output of the A / D converter (ADC) 431, the output of the differential arithmetic unit (DC) 432, the count of the ON count counter (OC) 433, and the fault notification, which is the output of the comparator (CMP) 436 are shown. In Figures 10 and 11, as in Figure 7, the ON period of a predetermined duty cycle is shown in a simplified manner.
[0069] As shown in Figure 10, if no short circuit occurs between the inductors, the short-circuit detection unit 43 corresponding to Phase 1 performs predetermined processing based on the PWM signal that drives the Phase 1 drive unit (DR1) 21. At the on-timing of the Phase 1 PWM signal, the current flowing through the drive unit 21 increases rapidly with a positive slope. As a result, the derivative value, which is the output of the differential arithmetic unit 432, switches from negative to a positive value, and the derivative value becomes greater than or equal to the threshold THd. The count (OC value) of the on-count counter 433 is reset with a predetermined time delay from the rising edge of the Phase 1 PWM signal, and counting begins. The count of the on-count counter becomes 1 with a predetermined time delay.
[0070] At the off-timing of the Phase 1 PWM signal, the derivative value is negative. However, because the coupled inductor 22C is used, the inductors 22 of each phase are magnetically coupled to each other, so at the on-timing of the Phase 2 and 3 PWM signals, the sign of the derivative value also switches from negative to positive. However, the slope of the current due to magnetic coupling is small compared to the slope of the current when the inductors are short-circuited, and the derivative value is less than the threshold THd. At the next on-timing of the Phase 1 PWM signal, the count of the on-count counter 433 is reset to 0. If no short circuit occurs between the inductors, the count of the on-count counter 433 alternates between 0 and 1. Therefore, the comparator 436 always outputs a low-level signal. In other words, the fault notification signal is kept in the off state.
[0071] Figure 11 shows the waveform when a short circuit occurs between the Phase 1 inductor 22 and the Phase 2 inductor 22 at timing T1. Here, we show an example where a short circuit occurs between the corresponding ends of the inductors 22 on the drive unit 21 side. When a short circuit occurs between the Phase 1 and Phase 2 inductors at timing T1, current flows through the Phase 1 inductor 22 even during the ON period of Phase 2. After timing T1, the current flowing through the Phase 1 drive unit 21 increases sharply at the ON timing of Phase 1 and Phase 2. As a result, the count of the ON count counter 433 becomes 2 in one cycle of the switching period.
[0072] At timing T2, which is the rising edge of the next ON timing of the Phase 1 PWM signal, the comparator 436 compares the count with the ON count threshold THn and determines that the count is 2 or greater than or equal to the ON count threshold THn. The comparator 436 outputs a high-level signal at timing T2, that is, it turns on the fault notification signal. The count of the ON count counter 433 is reset to 0 after a predetermined time delay from timing T2. The comparator 436 maintains the fault notification signal in the ON state while a short circuit occurs between the inductors.
[0073] Similar waveforms are observed for the other phases. In the case of the short-circuit detection unit 43 corresponding to Phase 2, predetermined processing is performed based on the PWM signal that drives the Phase 2 drive unit (DR2) 21. The count of the ON count counter 433 is reset with a predetermined delay from the rising edge of the Phase 2 PWM signal, and counting begins. At the rising edge of the next ON timing of the Phase 2 PWM signal, the comparator 436 compares the count with the ON count threshold THn. As described above, if a short circuit occurs between the inductors in Phases 1 and 2, current flows through the Phase 2 inductor 22 even during the ON period of Phase 1. As a result, the count of the ON count counter 433 becomes 2 in one cycle of the switching period, and the fault notification signal is turned ON.
[0074] Similarly, in the case of the short-circuit detection unit 43 corresponding to Phase 3, predetermined processing is performed based on the PWM signal that drives the Phase 3 drive unit (DR3) 21. The count of the ON count counter 433 is reset with a predetermined delay from the rising edge of the Phase 3 PWM signal, and counting begins. On the rising edge of the next ON timing of the Phase 3 PWM signal, the comparator 436 compares the count with the ON count threshold THn.
[0075] <Summary of the First Embodiment> The control device 10 of this embodiment includes a power control unit 40 (power control device) that controls the multiphase power supply 20, a PWM control unit 41 that controls the on / off switching of the drive unit 21 of the multiphase power supply 20, a current detection unit 42 that detects the current flowing through the drive unit 21, and a short-circuit detection unit 43. The short-circuit detection unit 43 detects a short circuit between the inductors of the coupled inductor 22C based on the switching period of the drive unit 21 and the current value detected by the current detection unit 42. The PWM control unit 41 corresponds to the control unit that controls the on / off switching of the drive unit 21.
[0076] When a short circuit occurs between an inductor 22 in any phase and an inductor 22 in another phase, current flows through the inductor 22 in the arbitrary phase even during the ON period of the drive unit 21 in the other phase, and the derivative value corresponding to the arbitrary phase becomes positive and greater than or equal to a threshold. The short circuit detection unit 43 determines that an inductor short has occurred between phases including the arbitrary phase if the derivative value corresponding to the arbitrary phase becomes positive and greater than or equal to a threshold THd during the OFF period of the drive unit 21 in the arbitrary phase. Therefore, the control device 10 can detect an inductor short in the coupled inductor 22C.
[0077] As illustrated, the short-circuit detection unit 43 may determine the presence or absence of a short circuit between inductors based on the number of times the differential value is positive and greater than or equal to the threshold THd during one cycle of the switching period. As described above, when a short circuit between inductors occurs, current flows through the inductor 22 of any phase even during the ON period of the drive unit 21 of other phases, and the differential value corresponding to any phase becomes positive and greater than or equal to the threshold THd. As a result, the differential value becomes positive and greater than or equal to the threshold THd multiple times in one cycle. Therefore, the presence or absence of a short circuit between inductors can be determined by the number of times in a predetermined period.
[0078] As illustrated, the threshold THd may be set to a predetermined value greater than the derivative value corresponding to any phase when the drive unit 21 of the other phases (excluding the arbitrary phase) is turned on, in a state where no short circuit occurs between the inductors. In the coupled inductor 22C, due to magnetic coupling, the current of any phase shows a positive slope during the on-period of the other phases. By setting the threshold THd as described above, false judgments can be suppressed and the detection accuracy of short circuits between inductors can be improved.
[0079] As illustrated, the short-circuit detection unit 43 may detect one cycle of multiple phases based on the control signal of the drive unit 21. This allows processing to be performed based on the control signal. For example, the presence or absence of a short circuit between inductors can be determined by the number of occurrences within a predetermined period.
[0080] As illustrated, the control device 10 may further include a multiphase power supply 20 and a processor 30 in addition to the power supply control unit 40. The control device 10 can function as an electronic control unit (ECU).
[0081] <Variation> As shown in Figure 12, the short-circuit detection unit 43 may have a timer 437. The timer 437 counts the switching period of the corresponding phase. The output of the timer 437 can be used to reset the ON count counter 433 or to perform a judgment on the comparator 436. By using the timer 437, a PWM signal (control signal) is not required. This reduces the connection interface between the short-circuit detection unit 43 and the peripherals.
[0082] (Second Embodiment) This embodiment is a modification based on the prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, a short-circuit detection unit was provided for each phase. That is, the same number of short-circuit detection units as the number of drive units were provided. Alternatively, the number of short-circuit detection units may be one less than the number of drive units.
[0083] Figure 13 shows an example of a control device according to this embodiment. Figure 13 corresponds to Figure 1. The control device 10 includes a power supply control unit 40. The multiphase power supply 20 has three phases. The multiphase power supply 20 has three drive units 21. The short-circuit detection unit 43 includes a short-circuit detection unit (SD1) 43 corresponding to Phase 1 and a short-circuit detection unit (SD3) 43 corresponding to Phase 3. The short-circuit detection unit 43 does not include a short-circuit detection unit (SD2) 43 corresponding to Phase 2. The other configurations are the same as those described in the prior embodiment.
[0084] <Summary of the second embodiment> As illustrated, the number of short-circuit detection units 43 may be one less than the number of drive units 21. If the number of drive units 21, i.e., the number of phases, is N, then even if the number of short-circuit detection units 43 is N-1, it is still possible to detect short circuits between inductors. This allows for a simplified configuration while achieving the same effect as a configuration with the same number of short-circuit detection units 43 as the number of drive units 21.
[0085] (Third embodiment) This embodiment is a modification based on the prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, the derivative value itself was used. Alternatively, the average value of the derivatives may be used as the derivative value.
[0086] Figure 14 is a flowchart showing an example of the processing performed by the short-circuit detection unit in the control device according to this embodiment. Figure 14 corresponds to Figure 9. The configuration of the short-circuit detection unit 43 is the same as in the prior embodiment. As shown in Figure 14, the processing in steps S10, S20, S30, S40, S60, S70, S80, S90, S100, and S110 is the same as in the prior embodiment.
[0087] After executing the process in step S30, the short-circuit detection unit 43 then calculates the average value of the derivatives (step S35). The average value is the average value of the derivatives over a predetermined period. The predetermined period is shorter than one cycle of the switching period. The predetermined period may also be shorter than, for example, the ON period of the corresponding phase.
[0088] Next, the short circuit detection unit 43 determines whether the sign of the average value calculated in step S35 has changed from negative to positive (step S40A). If the sign has changed to positive, the short circuit detection unit 43 then determines whether the average value is greater than or equal to the threshold THd (step S50A).
[0089] If the average value of the derivatives is greater than or equal to the threshold THd, the short circuit detection unit 43 then executes the process in step S60. If the sign of the average value does not change from negative to positive in step S40A, the short circuit detection unit 43 executes the process from step S20 onwards again. Similarly, if the average value is less than the threshold THd in step S50A, the short circuit detection unit 43 executes the process from step S20 onwards again.
[0090] The differential arithmetic unit 432 may calculate the average value of the derivatives and output the average value. The ON count counter 433 may calculate the average value of the derivatives. An average value calculation unit may be provided between the differential arithmetic unit 432 and the ON count counter 433, which holds the output of the differential arithmetic unit 432 for a predetermined period and calculates the average value. The other configurations are the same as those described in the prior embodiment.
[0091] <Summary of the third embodiment> As illustrated, the short-circuit detection unit 43 may determine whether the derivative value is positive and above a threshold by using the average value of the derivative value over a predetermined period shorter than one cycle of the switching period. This reduces false judgments due to noise. In other words, it improves the detection accuracy of short circuits between inductors. For example, even if the sign of the derivative value changes due to the influence of noise, using the average value can reduce false judgments due to the sign change. For example, even if the derivative value momentarily exceeds the threshold THd due to the influence of noise, using the average value can reduce false judgments regarding the threshold THd.
[0092] (Fourth Embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, the short-circuit detection unit was provided separately from the other elements constituting the control device. Alternatively, the short-circuit detection unit may be provided integrally with the other elements constituting the control device.
[0093] Figure 15 shows an example of a control device according to this embodiment. Figure 15 corresponds to Figure 1. In the power control unit 40 of the control device 10, the short-circuit detection unit 43 is provided in the PWM control unit 41. The short-circuit detection unit 43 is provided integrally with the PWM control unit 41. In the exemplary control device 10, three short-circuit detection units 43 corresponding to three phases are provided within a single PWM control unit 41. The other configurations are the same as those described in the prior embodiment.
[0094] <Summary of the fourth embodiment> As illustrated, the short-circuit detection unit 43 may be provided in the PWM control unit 41. The PWM control unit 41 corresponds to the control unit that controls the on / off state of the drive unit 21. By providing the short-circuit detection unit 43 within the PWM control unit 41, the configuration of the power supply control unit 40, and consequently the control device 10, can be simplified compared to using discrete components. Furthermore, the short-circuit detection unit 43 can be constructed at a low cost.
[0095] <Variation> As shown in Figure 16, the short-circuit detection unit 43 may be provided in the drive unit 21. By providing the short-circuit detection unit 43 in the drive unit 21 of the corresponding phase, the configuration of the control device 10 can be simplified compared to using discrete components. In addition, the short-circuit detection unit 43 can be constructed at a low cost.
[0096] As shown in Figure 17, the short-circuit detection unit 43 may be provided in the processor 30. By providing the short-circuit detection unit 43 within the processor 30, the configuration of the control device 10 can be simplified compared to using discrete components. In addition, the short-circuit detection unit 43 can be constructed at a low cost.
[0097] (Fifth embodiment) This embodiment is a modification based on a prior embodiment, and the description of the prior embodiment can be referenced. In the prior embodiment, the short-circuit detection unit was provided separately from the other elements constituting the control device. Alternatively, the short-circuit detection unit may be provided integrally with the other elements constituting the control device.
[0098] <Effects of load fluctuations> Figures 18 and 19 show the effects of load fluctuations in a reference example where the control described later is not performed. Figure 18 shows the Iout and Vout1 waveforms under normal conditions. Figure 19 shows the Iout and Vout1 waveforms when a short circuit occurs between inductors. Figures 18 and 19 show the transition from high-load processing to low-load processing. Iout is the current consumption of the processor 30.
[0099] In the normal operation shown in Figure 18, even if the current consumption Iout fluctuates rapidly, i.e., if the load fluctuates rapidly, the output voltage Vout1 will not exceed the operating range guaranteed by the processor 30. However, in the case of a short circuit between inductors shown in Figure 19, the short circuit reduces the number of phases in which the coupled inductor 22C acts. In other words, the effective inductance increases, and the ability of the output voltage Vout1 to follow the load response deteriorates. Because the load fluctuation characteristics deteriorate in this way, there is a risk that the output voltage Vout1 may exceed the operating range guaranteed by the processor 30.
[0100] In the reference example, unlike the control device 10 shown in this embodiment, the processor 30 does not perform any corresponding processing when a short circuit occurs between inductors. Therefore, there is a risk that the processor 30 may malfunction in cases where the load changes rapidly, such as when switching from automatic operation mode to manual operation mode.
[0101] <Processing performed by the processor> Figure 20 shows an example of processing performed by the processor in the control device according to this embodiment. When the processor 30 of the control device 10 is powered on and started up, for example, it performs the processing shown in Figure 20.
[0102] The processor 30 determines whether or not there is a fault notification from the short-circuit detection unit 43 (step S300). The processor 30 determines whether or not it has received a fault notification signal indicating a short circuit between inductors. If there is no fault notification, the process in step S300 is repeated.
[0103] If a failure notification is received, the processor 30 switches to low-load processing (step S310) and terminates the series of processes. If high-load processing is being performed, the process in step S310 causes the processor 30 to perform low-load processing. If low-load processing is being performed, the process in step S310 causes the processor 30 to maintain low-load processing. The processor 30 maintains low-load processing, for example, until the failure notification is cleared. The other configurations are the same as those described in the prior embodiment.
[0104] <Summary of the Fifth Embodiment> As illustrated, when the processor 30 receives a fault notification from the short-circuit detection unit 43, it may reduce the processing load compared to before the fault notification was received. This suppresses abrupt fluctuations in the load when a short circuit occurs between inductors. Therefore, even if the load fluctuation characteristics of the multi-phase power supply 20 deteriorate due to a short circuit between inductors, it is possible to prevent the output voltage from exceeding the operating range guaranteed by the processor 30.
[0105] <Variation> As shown in Figure 21, the processor 30 may determine that the coupled inductor 22C is short-circuited when multiple short-circuit detection units 43 detect a short circuit between inductors. In Figure 21, the processor 30 executes the process of step S300A instead of the process of step S300. In S300A, the processor 30 determines that a short circuit between inductors has occurred when it receives multiple fault notifications, that is, when it receives multiple fault notification signals indicating a short circuit between inductors. Then it executes the process of step S310.
[0106] A short circuit between inductors occurs, for example, between two adjacent inductors 22 (coils 25). In a configuration where a short circuit detection unit 43 is provided individually for each phase, if a short circuit occurs between two inductors 22, for example, two fault notifications are output to the processor 30 at the timing when they overlap. When the processor 30 receives the two fault notifications, it determines that a short circuit between inductors has occurred. Since the short circuit between inductors is determined by the results of multiple short circuit detection units 43, false detections can be suppressed. Note that the processing in step S300A is not limited to combination with step S310.
[0107] (Other embodiments) The disclosures in this specification and drawings are not limited to the exemplary embodiments. The disclosures include the exemplary embodiments and variations thereof by those skilled in the art. For example, the disclosures are not limited to combinations of parts and / or elements shown in the embodiments. The disclosures are implementable in a variety of combinations. The disclosures may have additional parts that can be added to the embodiments. The disclosures include those in which parts and / or elements of the embodiments have been omitted. The disclosures include substitutions or combinations of parts and / or elements between one embodiment and another. The scope of the disclosed technical areas is not limited to the descriptions of the embodiments. Some of the scope of the disclosed technical areas are indicated by the claims and should be understood to include all modifications within the meaning and scope equivalent to the claims.
[0108] The disclosures in the specification and drawings are not limited by the claims. The disclosures in the specification and drawings encompass the technical ideas described in the claims and extend to a wider and more diverse range of technical ideas than those described in the claims. Therefore, a variety of technical ideas can be extracted from the disclosures in the specification and drawings without being bound by the claims.
[0109] When an element or layer is referred to as “on top of,” “connected to,” “linked to,” or “joined,” it may be directly on top of, connected to, or joined to another element or layer, and there may also be an intervening element or layer. In contrast, when an element is referred to as “directly on top of,” “directly connected to,” “directly linked to,” or “directly joined to” another element or layer, there is no intervening element or layer. Other words used to describe relationships between elements should be interpreted in a similar manner (e.g., “between” vs. “directly between,” “adjacent” vs. “directly adjacent,” etc.). As used in this specification, the term “and / or” includes any combination and all combinations relating to one or more of the enumerated items relating to each other. That is, the statement A and / or B means at least one of A and B.
[0110] Spatially relative terms such as "inside," "outside," "back," "below," "low," "above," and "high" are used here to facilitate descriptions of the relationship between one element or feature and other elements or features, as illustrated. Spatially relative terms may be intended to encompass different orientations of the device in use or operation, in addition to the orientation depicted in the drawings. For example, if the device in the drawing is turned upside down, an element described as "below" or "directly below" another element or feature will be oriented "above" the other element or feature. Thus, the term "below" can encompass both up and down orientations. The device may also be oriented in other directions (it may be rotated 90 degrees or in other directions), and the spatially relative descriptors used in this specification will be interpreted accordingly.
[0111] The example shown includes at least a PWM control unit 41, a current detection unit 42, and a short-circuit detection unit 43, but is not limited to this. The device may not include a PWM control unit 41, but may include a current detection unit 42 and a short-circuit detection unit 43.
[0112] As described above, if a short circuit occurs between an inductor 22 in any phase and an inductor 22 in another phase, current flows through the inductor 22 in the arbitrary phase even during the ON period of the drive unit 21 in the other phase, and the derivative value corresponding to the arbitrary phase becomes positive and greater than or equal to a threshold. Therefore, for example, the system may be configured to detect the OFF period of the drive unit 21 in any phase based on a PWM signal or an internal timer, and if the derivative value corresponding to the arbitrary phase becomes positive and greater than or equal to a threshold THd during this OFF period, it may be determined that a short circuit has occurred between inductors in the phases including the arbitrary phase.
[0113] (Disclosure of technical ideas) This specification discloses several technical concepts, as listed in the following paragraphs. Some paragraphs are written in a multiple dependent form, where subsequent paragraphs optionally refer to preceding paragraphs. Furthermore, some paragraphs are written in a multiple dependent form, referring to other multiple dependent forms. These paragraphs written in multiple dependent forms define several technical concepts.
[0114] <Technical philosophy 1> A control unit (41) outputs a control signal to the drive unit of a multiphase power supply (20) which has multiple phases including a drive unit (21) and an inductor (22), and inductors in each phase are configured by a coupled inductor (22C), and controls the on / off state of the drive unit. A current detection unit (42) for detecting the current flowing through the drive unit, A short-circuit detection unit (43) detects a short circuit between the inductors of the coupled inductor based on the switching period of the drive unit and the current value detected by the current detection unit, Equipped with, The control device includes a short-circuit detection unit which determines that a short circuit has occurred between inductors in a phase including the arbitrary phase if the derivative of the current value corresponding to the arbitrary phase is positive and greater than or equal to a threshold value during the off period of the drive unit in the arbitrary phase.
[0115] <Technical philosophy 2> The control device according to technical concept 1, wherein the short-circuit detection unit determines whether or not there is a short circuit between the inductors based on the number of times the differential value is positive and equal to or greater than a threshold value during one cycle of the switching period.
[0116] <Technical philosophy 3> The control device according to Technical Concept 1 or Technical Concept 2, wherein the threshold value is a predetermined value greater than the derivative value corresponding to any phase when the drive unit of any of the phases other than the arbitrary phase is turned on, in a state in which no short circuit occurs between the inductors.
[0117] <Technical philosophy 4> The control device according to any one of the technical concepts 1 to 3, wherein the short-circuit detection unit determines whether the derivative value is positive and greater than or equal to a threshold value by using the average value of the derivative value over a predetermined period shorter than one cycle of the switching period.
[0118] <Technical philosophy 5> The control device according to technical concept 2, wherein the short-circuit detection unit detects one period of the switching cycle based on the control signal.
[0119] <Technical philosophy 6> The control device according to any one of technical concepts 1 to 5, wherein the number of short-circuit detection units is one less than the number of drive units.
[0120] <Technical philosophy 7> The multiphase power supply (20) and, A processor (30) that operates by receiving power from the aforementioned multi-phase power supply, A control device that further includes the features described in any one of the technical concepts 1 to 6.
[0121] <Technical philosophy 8> The short-circuit detection unit is provided in the control unit, and the control device is according to any one of the technical concepts 1 to 7.
[0122] <Technical philosophy 9> The control device according to technical concept 7, wherein the short-circuit detection unit is provided in the drive unit.
[0123] <Technical Thought 10> The short-circuit detection unit is provided in the processor, and is a control device according to the technical concept 7.
[0124] <Technical Thought 11> When the short-circuit detection unit determines that a short circuit has occurred between the inductors, it notifies the processor of the fault. The control device according to technical concept 7, wherein the processor, upon receiving the failure notification, reduces the processing load compared to before receiving the failure notification.
[0125] <Technical Thought 12> The control device according to technical concept 7, wherein the processor determines that a short circuit between inductors has occurred when multiple short-circuit detection units detect a short circuit between inductors. [Explanation of Symbols]
[0126] 10...Control device, 20...Multiphase power supply, 21...Drive unit, 21H, 21L...MOSFET, 22...Inductor, 22C...Coupling inductor, 23...Capacitor, 24...Core, 241...Core core, 242, 243...End core, 25...Coil, 251...Main body, 2511, 2512...Bottom wall, 2513, 2514...Side wall, 2515...Top wall, 252, 253...Terminal section, 30...Processor, 40...Power supply control unit, 41...PWM control unit, 42...Current detection unit, 43...Short circuit detection unit, 431...A / D converter, 432...Differentiator, 433...On count counter, 434...Rising edge detection unit, 435...Delay unit, 436...Comparator, 437...Timer
Claims
1. A control unit (41) outputs a control signal to the drive unit of a multiphase power supply (20) which has multiple phases including a drive unit (21) and an inductor (22), and inductors in each phase are configured by a coupled inductor (22C), and controls the on / off state of the drive unit. A current detection unit (42) for detecting the current flowing through the drive unit, A short-circuit detection unit (43) detects a short circuit between the inductors of the coupled inductor based on the switching period of the drive unit and the current value detected by the current detection unit, Equipped with, The control device includes a short-circuit detection unit which determines that a short circuit has occurred between inductors in a phase including the arbitrary phase if the derivative of the current value corresponding to the arbitrary phase is positive and greater than or equal to a threshold value during the off period of the drive unit in the arbitrary phase.
2. The control device according to claim 1, wherein the short-circuit detection unit determines whether or not there is a short circuit between the inductors based on the number of times the differential value is positive and equal to or greater than a threshold value during one cycle of the switching period.
3. The control device according to claim 1 or 2, wherein the threshold value is a predetermined value greater than the differential value corresponding to any phase when the drive unit of any phase other than the arbitrary phase is turned on, in a state in which no short circuit occurs between the inductors.
4. The control device according to claim 3, wherein the short-circuit detection unit determines whether the derivative value is positive and greater than or equal to a threshold value using the average value of the derivative value over a predetermined period shorter than one cycle of the switching period.
5. The control device according to claim 2, wherein the short-circuit detection unit detects one period of the switching cycle based on the control signal.
6. The control device according to claim 3, wherein the number of short-circuit detection units is one less than the number of drive units.
7. The multiphase power supply (20) and, A processor (30) that operates by receiving power from the multi-phase power supply, The control device according to claim 1 or claim 2, further comprising:
8. The control device according to claim 1 or claim 2, wherein the short-circuit detection unit is provided in the control unit.
9. The control device according to claim 7, wherein the short-circuit detection unit is provided in the drive unit.
10. The control device according to claim 7, wherein the short-circuit detection unit is provided in the processor.
11. When the short-circuit detection unit determines that a short circuit has occurred between the inductors, it notifies the processor of the fault. The control device according to claim 7, wherein the processor, upon receiving the failure notification, reduces the processing load compared to before receiving the failure notification.
12. The control device according to claim 7, wherein the processor determines that a short circuit between inductors has occurred when a plurality of short-circuit detection units detect a short circuit between inductors.