Power supply device, program, and control method

Abstract

To provide a power supply and a program that can continue to supply power from a switching power supply to a drive circuit while suppressing the effects of noise generated by the switching control of the switching power supply.SOLUTION: A PCU 30 includes a power supply IC 70 and an insulated power supply 100 that supplies power to a drive circuit 62 for a switch SA of an inverter by switching control performed by the power supply IC 70. The drive circuit 62 has a function to operate by receiving power from the insulated power supply 100 and monitoring the state of the switch SA. The power supply IC 70 changes the switching mode of the insulated power supply 100 in a first state, such as during external charging, from the switching mode of the insulated power supply 100 in a second state in which switching control of the switch SA is performed to drive a rotating electric machine.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present disclosure relates to a power supply device and a program that are applied to a system including a power storage unit, an inverter connected to the power storage unit, and a drive circuit that drives a switch of the inverter. [Background technology]

[0002] As described in Patent Document 1, a known power supply device of this type intermittently operates a switching power supply that supplies power to a drive circuit during external charging control in which a power storage unit is charged from an external power supply, thereby reducing noise generated by switching control of the switching power supply. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2022-118417 Summary of the Invention [Problem to be solved by the invention]

[0004] When the switching power supply is operated intermittently, the period during which the power supply from the switching power supply to the drive circuit is stopped becomes long. During the power supply stop period, the drive circuit cannot be operated, and the drive circuit may not be able to monitor the state of the switch of the inverter (for example, an overcurrent state or an overheat state).

[0005] A primary object of the present disclosure is to provide a power supply device and a program that can continue to supply power from a switching power supply to a drive circuit while suppressing the effects of noise. [Means for solving the problem]

[0006] The present disclosure relates to a power storage device, An inverter connected to the power storage unit; a rotating electric machine having an armature winding connected to the inverter; A drive circuit that drives a switch of the inverter; A power supply device applied to a system including: a switching power supply having a power supply control unit and supplying power to the drive circuit by switching control of the power supply control unit; the drive circuit is powered by the switching power supply and has a function of monitoring a state of the switch; The power supply control unit performs a change process to change the switching mode of the switching power supply in a first state, in which the storage unit is being charged from an external power supply via the inverter or switching control of the switch is stopped, from the switching mode of the switching power supply in a second state, in which switching control of the switch is being performed to drive the rotating electric machine.

[0007] According to the power supply device of the present disclosure, it is possible to continue supplying power from the switching power supply to the drive circuit while suppressing the effects of noise.

[0008] The power supply device of the present disclosure can be embodied, for example, as follows.

[0009] The power supply control unit is Setting the switching frequency of the switching power supply in the second state to a frequency within a specific frequency range; The change process includes a process of shifting the switching frequency of the switching power supply in the first state to a frequency outside the specific frequency range.

[0010] There may be a requirement that the noise level in a particular frequency range be below an acceptable value in the first state. This requirement may be, for example, a legal or regulatory requirement.

[0011] Therefore, as a change process, the power supply control unit performs a process of shifting the switching frequency of the switching power supply in the first state to a frequency outside the specific frequency range, thereby making it possible to continue supplying power from the switching power supply to the drive circuit while keeping the noise level below an allowable value in the specific frequency range. [Brief description of the drawings]

[0012] [Figure 1] 1 is a diagram showing the overall configuration of a vehicle and an external charging device according to a first embodiment. [Diagram 2] FIG. 1 is a diagram showing a configuration of an in-vehicle system. [Diagram 3] FIG. 2 shows the configuration of a PCU. [Figure 4] 4 is a flowchart of a switching frequency change instruction process executed by a microcomputer. [Diagram 5] 5 is a flowchart of a switching control process of a control switch executed by a power supply control unit. [Figure 6] FIG. 13 is a diagram illustrating an effect of lowering the switching frequency. [Figure 7] FIG. 11 is a diagram showing the configuration of a PCU according to a second embodiment. [Figure 8] 5 is a flowchart of a target voltage change process executed by a microcomputer. [Figure 9] 5 is a flowchart of a switching control process of a control switch executed by a power supply control unit. [Figure 10] FIG. 4 is a diagram showing an effect of lowering a target voltage. [Figure 11] FIG. 13 is a diagram showing the configuration of a PCU according to a third embodiment. [Figure 12] FIG. 4 is a diagram showing an example of a gate switching circuit. [Figure 13] 5 is a flowchart of a process for changing a gate resistance value executed by a microcomputer. [Figure 14] 5 is a flowchart of a switching control process of a control switch executed by a power supply control unit. [Figure 15] FIG. 13 is a diagram showing the configuration of a PCU according to a fourth embodiment. [Figure 16]4 is a flowchart of a switching frequency change instruction process executed by a microcomputer. [Figure 17] FIG. 13 is a diagram showing the configuration of a PCU according to a fifth embodiment. [Figure 18] 4 is a flowchart of a switching frequency change instruction process executed by a microcomputer. [Figure 19] FIG. 13 is a diagram showing the configuration of a PCU according to a sixth embodiment. [Figure 20] 4 is a flowchart of a switching frequency change instruction process executed by a microcomputer. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Several embodiments will be described with reference to the drawings. In several embodiments, functionally and / or structurally corresponding and / or associated parts may be given the same reference numerals or reference numerals with different digits of 100 or more. For corresponding and / or associated parts, the description of other embodiments may be referred to.

[0014] First Embodiment DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power supply device according to a first embodiment of the present disclosure will now be described with reference to the drawings. The power supply device of this embodiment is mounted on an electrically powered vehicle such as an electric car or a hybrid car.

[0015] As shown in Fig. 1, a vehicle 10 includes, as an on-board system, wheels 11, a high-voltage storage battery 20 (corresponding to a "power storage unit"), a low-voltage storage battery 21, a power control unit (hereinafter, PCU) 30, and a higher-level control device (hereinafter, higher-level ECU) 60. The high-voltage storage battery 20 is a chargeable and dischargeable secondary battery, and has a terminal voltage of, for example, 100 V or more. The high-voltage storage battery 20 is, for example, a lithium-ion storage battery or a nickel-metal hydride storage battery. The low-voltage storage battery 21 is a chargeable and dischargeable storage battery having an output voltage (specifically, a rated voltage) lower than that of the high-voltage storage battery 20, and is, for example, a lead storage battery. The low-voltage storage battery 21 has an output voltage of, for example, 1 / 10 or less of the output voltage of the high-voltage storage battery 20.

[0016] The high-voltage storage battery 20 can be externally charged by an external charging device 15 (corresponding to an "external power source") arranged outside the vehicle 10. The external charging device 15 is, for example, a stationary device.

[0017] Next, the PCU 30 and the configuration related to external charging will be described with reference to FIG.

[0018] The PCU 30 includes a rotating electric machine 40 and an inverter 50. The rotating electric machine 40 applies rotational power to wheels 11 (drive wheels) of the vehicle 10 to make the vehicle 10 run. The rotating electric machine 40 of this embodiment is a synchronous machine, specifically a Y-connected permanent magnet synchronous machine. The rotating electric machine 40 includes a rotor 41 capable of transmitting power to the drive wheels, and U-, V-, and W-phase windings 42U, 42V, and 42W that form a stator.

[0019] In this embodiment, a neutral point clamped three-level inverter will be described as an example of the inverter 50. However, the configuration of the inverter 50 is not limited to the neutral point clamped type.

[0020] The inverter 50 includes U-phase first to fourth switches Su1 to Su4, V-phase first to fourth switches Sv1 to Sv4, W-phase first to fourth switches Sv1 to Sv4, a first capacitor 51, a second capacitor 52, and first to sixth clamp diodes Dc1 to Dc6. In this embodiment, the switches Su1 to Su4, Sv1 to Sv4, and Sw1 to Sw4 are voltage-controlled semiconductor switching elements, specifically IGBTs. Freewheel diodes Du1 to Du4, Dv1 to Dv4, and Dw1 to Dw4 are connected in inverse parallel to the switches Su1 to Su4, Sv1 to Sv4, and Sw1 to Sw4.

[0021] The first capacitor 51 and the second capacitor 52 are connected in series. The high-voltage storage battery 20 is connected in parallel to the series connection of the first and second capacitors 51, 52. The first capacitor 51 has, for example, the same capacitance as the capacitance of the second capacitor 52. In this embodiment, the connection point between the first capacitor 51 and the second capacitor 52 is referred to as an inverter neutral point O.

[0022] The U-phase first to fourth switches Su1 to Su4 are connected in series with their emitters, which are low potential terminals, connected to their collectors, which are high potential terminals. A positive terminal of the high voltage storage battery 20 is connected to the collector of the U-phase first switch Su1, and a negative terminal of the high voltage storage battery 20 is connected to the emitter of the U-phase fourth switch Su4. A first end of the U-phase winding 42U is connected to a connection point between the U-phase second switch Su2 and the U-phase third switch Su3 via a U-phase conductive path 53U. The U-phase conductive path 53U includes, for example, a conductive member such as a bus bar.

[0023] The cathode of the first clamp diode Dc1 is connected to the connection point between the U-phase first switch Su1 and the U-phase second switch Su2, and the anode of the first clamp diode Dc1 is connected to the cathode of the second clamp diode Dc2. The anode of the second clamp diode Dc2 is connected to the connection point between the U-phase third switch Su3 and the U-phase fourth switch Su4.

[0024] The configuration of the V- and W-phases is basically the same as that of the U-phase. Therefore, the configuration of the V- and W-phases will be omitted as appropriate in the following description. A first end of the V-phase winding 42V is connected to a connection point between the V-phase second switch Sv2 and the V-phase third switch Sv3 via a V-phase conductive path 53V. A first end of the W-phase winding 42W is connected to a connection point between the W-phase second switch Sw2 and the W-phase third switch Sw3 via a W-phase conductive path 53W. The V-phase conductive path 53V and the W-phase conductive path 53W include conductive members such as bus bars. Second ends of the phase windings 42U, 42V, and 42W are connected to the neutral point of the armature winding.

[0025] Next, the external charging-related configuration of the in-vehicle system will be described.

[0026] The in-vehicle system includes a U-phase cutoff switch 54U and a V-phase cutoff switch 54V as components for electrically connecting or disconnecting the inverter 50 and the armature winding of the rotating electric machine 40. Each of the cutoff switches 54U, 54W allows the flow of bidirectional current when turned on, and cuts off the flow of bidirectional current when turned off.

[0027] The in-vehicle system includes, as components for electrically connecting the inverter 50 to the external charging device 15, a vehicle-side connector 56, a negative electrode wiring 55A, a positive electrode wiring 55B, a first changeover switch 57A, and a second changeover switch 57B.

[0028] The vehicle-side connector 56 is detachably connected to the external connector 16 of the external charging device 15. In a state in which the vehicle-side connector 56 and the external connector 16 are mechanically connected to each other, the positive terminal of the vehicle-side connector 56 and the positive terminal 101 of the external charging device 15 are electrically connected to each other, and the negative terminal of the vehicle-side connector 56 and the negative terminal of the external charging device 15 are electrically connected to each other.

[0029] The positive electrode wiring 55B connects a portion of the U-phase conductive path 53U that is closer to the inverter 50 than the U-phase cutoff switch 54U to the positive electrode terminal of the vehicle-side connector 56. A second changeover switch 57B is provided in the positive electrode wiring 55B. The second changeover switch 57B allows the flow of current in both directions when turned on, and cuts off the flow of current in both directions when turned off.

[0030] The negative wiring 55A connects a portion of the V-phase conductive path 53V that is closer to the inverter 50 than the V-phase cutoff switch 54V to the negative terminal of the vehicle-side connector 56. A first changeover switch 57A is provided in the negative wiring 55A. The first changeover switch 57A allows the flow of bidirectional current when turned on and cuts off the flow of bidirectional current when turned off.

[0031] The PCU 30 includes a current sensor 22. The current sensor 22 detects a current flowing through each of the conductive paths 53U, 53V, and 53W. A detection value of the current sensor 22 is input to a microcomputer 61 included in the PCU 30.

[0032] The microcomputer 61 is a control unit included in the PCU 30, and performs drive control of the rotating electric machine 40 for running the vehicle 10 and external charging control.

[0033] The drive control of the rotating electric machine 40 is a control for controlling the control amount (torque in this embodiment) of the rotating electric machine 40 to a command value (command torque Trq*), and is a switching control of each switch Su1 to Sw4 of the inverter 50. When the output voltage of the high-voltage storage battery 20 is Vh and the potential of the inverter neutral point O is 0, the inverter 50 outputs one of three different potentials "Vh / 2", "0", and "-Vh / 2" to each phase of the rotating electric machine 40 by switching control of each switch Su1 to Sw4. In more detail, taking the U phase as an example, the U phase first and second switches Su1 and Su2 are turned on and the U phase third and fourth switches Su3 and Su4 are turned off, so that "Vh / 2" is output to the U phase of the rotating electric machine 40. On the other hand, the U-phase second and third switches Su2 and Su3 are turned on and the U-phase first and fourth switches Su1 and Su4 are turned off, so that "0" is output to the U-phase. On the other hand, the U-phase third and fourth switches Su3 and Su4 are turned on and the U-phase first and second switches Su1 and Su2 are turned off, so that "-Vh / 2" is output to the U-phase. The command torque Trq* is input from the host ECU 60 to the microcomputer 61.

[0034] During drive control of the rotary electric machine 40, the host ECU 60 or the microcomputer 61 turns on the U-phase cutoff switch 54U and the V-phase cutoff switch 54V, and turns off the first changeover switch 57A and the second changeover switch 57B.

[0035] The external charging control is a control for charging the high-voltage storage battery 20 from the external charging device 15 via the inverter 50 while the vehicle 10 is stopped, and is a switching control of each switch of the inverter 50. In this embodiment, the external charging control is executed by the host ECU 60. In the external charging control, the host ECU 60 turns off the U-phase cutoff switch 54U and the V-phase cutoff switch 54V and turns on the first changeover switch 57A and the second changeover switch 57B by itself or by instructing the microcomputer 61. Note that the switching control of the inverter 50 in the external charging control is a publicly known technology described in paragraphs 0067 to 0083 of JP 2021-52450 A, etc., so please refer to this publication.

[0036] Incidentally, the microcomputers in the microcomputer 61 and the upper ECU 60 each include a CPU. The functions provided by the microcomputers in the microcomputer 61 and the upper ECU 60 can be provided by software recorded in a substantial memory device and a computer that executes the software, by software alone, by hardware alone, or by a combination of these. For example, when the microcomputers in the microcomputer 61 and the upper ECU 60 are provided by electronic circuits that are hardware, they can be provided by digital circuits including a large number of logic circuits, or by analog circuits. For example, the microcomputers in the microcomputer 61 and the upper ECU 60 execute programs stored in non-transitory tangible storage mediums as storage units that they include. The programs include, for example, programs for processes shown in FIGS. 4 and 5, which will be described later. The programs installed in the microcomputers in the microcomputer 61 and the upper ECU 60 are executed, thereby executing a method corresponding to the programs. The storage unit is, for example, a non-volatile memory. The programs stored in the storage unit can be downloaded and updated via a communication network such as the Internet, for example, over the air (OTA).

[0037] Next, a drive circuit 62 that drives the switches Su1 to Sw4 of the inverter 50 and an insulated power supply 100 that supplies the output power of the low-voltage storage battery 21 to the drive circuit 62 will be described with reference to Fig. 3. The switches Su1 to Sw4 of the inverter 50 basically have the same configuration. For this reason, in Fig. 3, the switches of the inverter 50 are indicated by SA.

[0038] The PCU 30 includes a drive circuit 62 and an insulated power supply 100. The drive circuit 62 is configured with an integrated circuit, and is provided individually corresponding to, for example, each of the switches Su1 to Sw4. A drive command signal for the switch SA is input to the drive circuit 62 from the microcomputer 61. The drive command signal is an ON command signal or an OFF command signal.

[0039] The isolated power supply 100 of this embodiment is a flyback type switching power supply. The isolated power supply 100 includes a power supply IC 70 as a "power supply control unit", a transformer 71, a control switch 72, first and second voltage dividing resistors 75A and 75B, and a capacitor 76. The control switch 72 of this embodiment is an N-channel MOSFET.

[0040] A first end of a primary coil 71A of the transformer 71 is connected to the positive terminal of the low-voltage storage battery 21. A second end of the primary coil 71A is connected to the drain of a control switch 72, and a source of the control switch 72 is connected to the ground of the low-voltage region.

[0041] The power supply IC 70 has a power supply terminal LVCC connected to a positive terminal of the low voltage storage battery 21. The power supply IC 70 is enabled to operate when power is supplied to the power supply IC 70 from the low voltage storage battery 21 via the power supply terminal LVCC.

[0042] The gate of the control switch 72 is connected to a control terminal LGP of the power supply IC 70. A ground in a low voltage region is connected to a ground terminal LGND of the power supply IC 70. The power supply IC 70 supplies a charging current to the gate of the control switch 72 using input power from the power supply terminal LVCC as a power source so that the gate-to-source voltage Vgs, which is the potential of the control terminal LGP relative to the potential of the ground terminal LGND, is equal to or higher than the threshold voltage of the control switch 72. This turns on the control switch 72. Meanwhile, the power supply IC 70 passes a discharging current from the gate of the control switch 72 to the ground terminal LGND so that the gate-to-source voltage Vgs is less than the threshold voltage. This turns off the control switch 72.

[0043] The power supply IC 70 performs switching control of the control switch 72 based on the duty ratio. The duty ratio is the ratio of an on-period Ton to one switching cycle Tsw of the control switch 72 (=Ton / Tsw).

[0044] A first end of the series connection of the first and second voltage dividing resistors 75A and 75B is connected to the positive terminal of the low voltage storage battery 21, and a second end of the series connection of the first and second voltage dividing resistors 75A and 75B is connected to the ground of the low voltage region. A detection terminal UVLO of the power supply IC 70 is connected to the connection point of the first and second voltage dividing resistors 75A and 75B.

[0045] When the power supply IC 70 determines that the input voltage of the detection terminal UVLO falls below the voltage threshold Vα, it performs an under voltage malfunction prevention process (Under Voltage Lock Out) to keep the control switch 72 off. On the other hand, when the power supply IC 70 determines that the input voltage exceeds a release threshold Vβ that is higher than the voltage threshold Vα and lower than the output voltage of the low-voltage storage battery 21, it stops the under voltage malfunction prevention process and resumes switching control of the control switch 72 to resume operation of the insulated power supply 100.

[0046] The isolated power supply 100 includes a diode 73 and a capacitor 74. An anode of the diode 73 is connected to a first end of a secondary coil 71B of the transformer 71. A first end of the capacitor 74 and a power supply terminal HVCC of the drive circuit 62 are connected to a cathode of the diode 73. A second end of the secondary coil 71B is connected to a second end of the capacitor 74. The drive circuit 62 is enabled when power is supplied to the drive circuit 62 from the output side of the isolated power supply 100 via the power supply terminal HVCC.

[0047] The control system is provided with a low voltage region and a high voltage region electrically insulated from the low voltage region. The low voltage region is provided with a low voltage storage battery 21, a host ECU 60, and a microcomputer 61. The high voltage region is provided with a high voltage storage battery 20, an inverter 50, and a rotating electric machine 40. An insulated power supply 100 is provided across the low voltage region and the high voltage region. In more detail, a power supply IC 70, a control switch 72, a primary coil 71A, etc. are provided in the low voltage region, and a secondary coil 71B, a drive circuit 62, etc. are provided in the high voltage region.

[0048] The gate of the switch SA of the inverter 50 is connected to a control terminal HGP of the drive circuit 62. The source of the switch SA is connected to a ground terminal HGND of the drive circuit 62. When the drive circuit 62 determines that an ON command signal has been input, the drive circuit 62 supplies a charging current to the gate of the switch SA using the input power from the power supply terminal HVCC as a power source so that the gate-emitter voltage Vge, which is the potential of the control terminal HGP relative to the potential of the ground terminal HGND, is equal to or higher than the threshold voltage of the switch SA. This turns the switch SA on. On the other hand, when the drive circuit 62 determines that an OFF command signal has been input, the drive circuit 62 flows a discharging current from the gate of the switch SA to the ground terminal HGND so that the gate-emitter voltage Vge is less than the threshold voltage. This turns the switch SA off.

[0049] The drive circuit 62 includes an overcurrent monitoring unit 62A and an overheat monitoring unit 62B. The overcurrent monitoring unit 62A acquires a detection value of a switch current sensor that detects a current flowing between the collector and emitter of the switch SA. When the overcurrent monitoring unit 62A determines that the acquired current of the switch SA exceeds a current threshold, it determines that an overcurrent abnormality has occurred in the switch SA, and turns off the switch SA.

[0050] The overheat monitoring unit 62B acquires a detection value of a switch temperature sensor that detects the temperature of the switch SA. When the overheat monitoring unit 62B determines that the acquired temperature of the switch SA exceeds a temperature threshold, it determines that the switch SA has an overheat abnormality, and turns off the switch SA.

[0051] The PCU 30 includes a setting change unit 80 as a component for notifying the power supply IC 70 of the driving state of the inverter 50, etc. Fig. 3 shows an example in which the setting change unit 80 includes first and second resistors 81 and 82 and a changeover switch 83. The changeover switch 83 connects either the first or second resistor 81 or 82 to a setting terminal LRT of the power supply IC 70. The resistance value of the first resistor 81 and the resistance value of the second resistor 82 are different.

[0052] The microcomputer 61 receives information from the host ECU 60 indicating that external charging control is being performed, information indicating that switching control of the switches Su1 to Sw4 of the inverter 50 is stopped, and information indicating that drive control of the rotating electric machine 40 for running the vehicle 10 is being performed. When the microcomputer 61 determines that the information indicating that external charging control is being performed or that the switching control is stopped has been input, the microcomputer 61 operates the changeover switch 83 to connect the setting terminal LRT to the first resistor 81. On the other hand, when the microcomputer 61 determines that the information indicating that drive control of the rotating electric machine 40 is being performed has been input, the microcomputer 61 operates the changeover switch 83 to connect the setting terminal LRT to the second resistor 82. The input voltage of the setting terminal LRT differs depending on whether the resistor connected to the setting terminal LRT is the first resistor 81 or the second resistor 82. Based on the input voltage of the setting terminal LRT, the power supply IC 70 can determine whether the current state is a state in which external charging control is being executed or a state in which switching control of the inverter 50 is stopped (corresponding to the "first state"), or a state in which drive control of the rotating motor 40 is being executed to run the vehicle 10 (the "second state").

[0053] Incidentally, when external charging control is being executed or when switching control of the inverter 50 is stopped, it is required that the level of noise (e.g., radiation noise, conduction noise) generated in association with switching control of the control switch 72 of the insulated power supply 100 be equal to or lower than the allowable value NLjde in a specific frequency range Rfjde. This requirement is, for example, a legal requirement. Specifically, for example, this requirement is determined from the viewpoint of suppressing the influence of noise on in-vehicle electronic devices. To achieve this requirement, the microcomputer 61 executes the process shown in FIG. 4, and the power supply IC 70 executes the process shown in FIG. 5.

[0054] FIG. 4 is a flowchart of the process executed by the microcomputer 61.

[0055] In step S10, based on the information transmitted from the higher-level ECU 60, it is determined whether the current state is a state in which external charging control is being executed, a state in which switching control of the inverter 50 is stopped, or a state in which drive control of the rotating motor 40 is being executed to run the vehicle 10.

[0056] If it is determined in step S10 that the current state is a state in which drive control of the rotating electric machine 40 is being executed, the process proceeds to step S11, and the power supply IC 70 is instructed via the setting change unit 80 to set the switching frequency fsw (=1 / Tsw) of the control switch 72 to a first frequency fH (e.g., 400 kHz). In more detail, the changeover switch 83 is operated so that the setting terminal LRT is connected to the first resistor 81. When the lower limit value of the specific frequency range Rfjde is RL and the upper limit value is RH, the first frequency fH is a frequency within the specific frequency range Rfjde (RL≦fH≦RH), and specifically, for example, a frequency that is higher than the lower limit value RL of the specific frequency range Rfjde and lower than the upper limit value RH.

[0057] On the other hand, when it is determined in step S10 that the current state is a state in which external charging control is being executed or a state in which switching control of the inverter 50 is stopped, the process proceeds to step S12, where the power supply IC 70 is instructed via the setting change unit 80 to set the switching frequency fsw of the control switch 72 to a frequency (e.g., 40 kHz) lower than the lower limit value RL of the specific frequency range Rfjde. In more detail, the changeover switch 83 is operated so that the setting terminal LRT and the second resistor 82 are connected. For example, when the second frequency fL is 40 kHz and the first frequency fH is 400 kHz, the second frequency fL becomes 1 / 10 of the first frequency fH.

[0058] The second frequency fL is, for example, a frequency that is 1 / 12 or more and 1 / 6 or less of the first frequency fH, desirably a frequency that is 1 / 11 or more and 1 / 7 or less of the first frequency fH, and more desirably a frequency that is 1 / 10.5 or more and 1 / 7.5 or less of the first frequency fH, or a frequency that is 1 / 10.5 or more and 1 / 8 or less of the first frequency fH.

[0059] The reason why the second frequency fL is set to a lower frequency than the first frequency fH is, for example, because the characteristics of the transformer 71 (e.g., frequency characteristics of gain, phase, and impedance) do not satisfy the required characteristics in a frequency range higher than the upper limit value RH of the specific frequency range Rfjde.

[0060] The reason why the second frequency fL is set to a lower frequency than the first frequency fH is, for example, to suppress the influence of the switching control of the control switch 72 on the electronic devices provided in the in-vehicle system. More specifically, the electronic devices include a radio receiver and a speaker. The radio receiver includes an AM receiver and an FM receiver. The AM receiver is a device that detects and demodulates a modulated wave in which a carrier wave is modulated by analog AM modulation, and outputs the modulated wave as an audio signal to a speaker. The FM receiver is a device that detects and demodulates a frequency-modulated modulated wave, and outputs the modulated wave as an audio signal to a speaker. Here, the frequency range that the AM broadcast can take is higher than the specific frequency range Rfjde, for example, "510 to 1720 kHz". The frequency range that the FM broadcast can take is even higher than the frequency range that the AM broadcast can take, for example, "76 to 108 MHz".

[0061] If the switching frequency fsw of the control switch 72 is shifted to a higher frequency side than the upper limit value RH of the specific frequency range Rfjde, the frequency of the noise generated by the switching control of the control switch 72 may be included in the frequency band of AM broadcasting. In this case, the noise is mixed into the audible frequency (sound) output from the speaker, causing discomfort to the user. Therefore, the second frequency fL is shifted to a frequency lower than the first frequency fH.

[0062] FIG. 5 is a flowchart of the process executed by the power supply IC 70.

[0063] In step S20, it is determined whether the switching frequency fsw of the control switch 72 is instructed to be the first frequency fH or the second frequency fL, based on the input voltage of the setting terminal LRT.

[0064] If it is determined in step S20 that the switching frequency fsw is set to the first frequency fH, the process proceeds to step S21, where the switching of the control switch 72 is controlled so that the switching frequency fsw of the control switch 72 becomes the first frequency fH.

[0065] On the other hand, if it is determined in step S20 that the switching frequency fsw is instructed to be the second frequency fL, the process proceeds to step S22, where switching control of the control switch 72 is performed so that the switching frequency fsw of the control switch 72 becomes the second frequency fL.

[0066] As shown in FIG. 6, by shifting the switching frequency fsw to a second frequency fL that is lower than the lower limit value RL of the specific frequency range Rfjde, the level of noise generated due to the switching control of the isolated power supply 100 can be kept below the permissible value NLjde in the specific frequency range Rfjde.

[0067] According to the present embodiment described above in detail, the switching frequency fsw of the control switch 72 of the insulated power supply 100 is set to a frequency within the specific frequency range Rfjde when the vehicle 10 is running, and is set to a frequency outside the specific frequency range Rfjde when external charging is performed or the inverter 50 is stopped. As a result, during external charging or when the inverter 50 is stopped, power can be supplied from the insulated power supply 100 to each drive circuit 62 while keeping the noise level below the allowable value NLjde in the specific frequency range Rfjde. Therefore, during external charging or when the inverter 50 is stopped, the overheat monitoring unit 62B can continue to monitor the switch SA for an overheat abnormality, and the overcurrent monitoring unit 62A can continue to monitor the switch SA for an overcurrent.

[0068] The power consumption of the drive circuit 62 during external charging is smaller than that during drive control of the rotating electric machine 40 to run the vehicle 10. This is because, for example, in each drive circuit 62, the number of times the inverter 50 is switched per specified period during external charging is smaller than that during drive control of the rotating electric machine 40. From the above, even if the switching frequency fsw of the insulated power supply 100 is reduced during external charging, it is possible to prevent a situation in which the drive power for the switch SA supplied from the insulated power supply 100 to the drive circuit 62 becomes insufficient.

[0069] <Modification of the first embodiment> The switching frequency fsw of the control switch 72 may be set to a frequency higher than the upper limit value RH of the specific frequency range Rfjde.

[0070] The host ECU 60 does not need to transmit information that switching control of the switches Su1 to Sw4 of the inverter 50 has been stopped to the microcomputer 61. In this case, in step S10 shown in FIG. 4, the state in which switching control of the inverter 50 has been stopped may be excluded from the state determination targets based on the information transmitted from the host ECU 60.

[0071] <Second embodiment> The second embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, in order to keep the noise level in the specific frequency range Rfjde below the allowable value NLjde, the output voltage of the isolated power supply 100 is reduced instead of the switching frequency fsw of the control switch 72.

[0072] 7, the isolated power supply 100 includes a feedback coil 90 as a "voltage detection coil." The feedback coil 90 detects the output voltage VCC (terminal voltage of the capacitor 74) of the isolated power supply 100, and transmits information about the detected output voltage VCC to the power supply IC 70. Based on input information from the feedback coil 90, the power supply IC 70 performs switching control of the control switch 72 to feedback-control the output voltage VCC to the target voltage Vtgt.

[0073] When the drive circuit 62 determines that the input voltage of the power supply terminal HVCC falls below the voltage threshold Vγ, it performs an under voltage lock out process to keep the switch SA off. On the other hand, when the drive circuit 62 determines that the input voltage exceeds the release threshold Vδ, it stops the under voltage lock out process and allows switching control of the switch SA. The release threshold Vδ is set to a value larger than the voltage threshold Vγ.

[0074] FIG. 8 is a flowchart of the process executed by the microcomputer 61.

[0075] If it is determined in step S10 that the current state is a state in which drive control of the rotating electric machine 40 is being executed, the process proceeds to step S13, and an instruction is given to the power supply IC 70 via the setting change unit 80 to set the target voltage Vtgt to the first voltage VH. In more detail, the changeover switch 83 is operated so that the setting terminal LRT and the first resistor 81 are connected.

[0076] On the other hand, when it is determined in step S10 that the current state is a state in which external charging control is being executed or a state in which switching control of the inverter 50 is stopped, the process proceeds to step S14, and an instruction is given to the power supply IC 70 via the setting change unit 80 to set the target voltage Vtgt to a second voltage VL lower than the first voltage VH. In more detail, the changeover switch 83 is operated so that the setting terminal LRT and the second resistor 82 are connected.

[0077] The second voltage VL may be set to a value equal to or greater than the voltage threshold value Vγ, thereby preventing the drive circuit 62 from performing low voltage malfunction prevention processing in conjunction with the reduction in the noise level.

[0078] FIG. 9 is a flowchart of the process executed by the power supply IC 70.

[0079] In step S30, it is determined whether the target voltage Vtgt is instructed to be the first voltage VH or the second voltage VL, based on the input voltage of the setting terminal LRT.

[0080] If it is determined in step S30 that the target voltage Vtgt is set to the first voltage VH, the process proceeds to step S31, where the target voltage Vtgt is set to the first voltage VH, and switching control of the control switch 72 is performed to feedback-control the output voltage VCC of the isolated power supply 100 to the first voltage VH.

[0081] On the other hand, if it is determined in step S30 that the target voltage Vtgt is instructed to be the second voltage VL, the process proceeds to step S32, where the target voltage Vtgt is set to the second voltage VL. Then, switching control of the control switch 72 is performed to feedback-control the output voltage VCC of the isolated power supply 100 to the second voltage VL. In this case, the duty ratio of the control switch 72 is made smaller than that in the process of step S31.

[0082] According to the present embodiment described above, as shown in FIG. 10, the level of noise generated due to switching control of the isolated power supply 100 can be kept below the permissible value NLjde in the specific frequency range Rfjde.

[0083] <Third embodiment> The third embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, in order to make the noise level in the specific frequency range Rfjde equal to or lower than the allowable value NLjde, the switching speed of the control switch 72 is reduced instead of the switching frequency fsw of the control switch 72.

[0084] As shown in FIG. 11, the isolated power supply 100 includes a gate switching circuit 110 for changing the switching speed of the control switch 72. The gate switching circuit 110 can have various circuit configurations. FIG. 12 shows an example of the gate switching circuit 110. The gate switching circuit 110 includes a first gate resistor 111A, a second gate resistor 111B, a first charge / discharge switch 112A, and a second charge / discharge switch 112B. The series connection of the first gate resistor 111A and the first charge / discharge switch 112A connects the control terminal LGP of the power supply IC 70 to the gate of the control switch 72. The series connection of the second gate resistor 111B and the second charge / discharge switch 112B also connects the control terminal LGP of the power supply IC 70 to the gate of the control switch 72.

[0085] The resistance value RGA of the first gate resistor 111A is smaller than the resistance value RGB of the second gate resistor 111B. The resistance value RGA of the first gate resistor 111A is, for example, "0.3×RGB≦RGA≦0.7×RGB", specifically, "0.4×RGB≦RGA≦0.6×RGB", and more specifically, "0.45×RGB≦RGA≦0.55×RGB".

[0086] FIG. 13 is a flowchart of the process executed by the microcomputer 61.

[0087] If it is determined in step S10 that the current state is a state in which drive control of the rotating electric machine 40 is being executed, the process proceeds to step S15, and an instruction is given to the power supply IC 70 via the setting change unit 80 to set the gate resistor connected to the gate of the control switch 72 to the first gate resistor 111A. More specifically, the changeover switch 83 is operated so that the setting terminal LRT and the first resistor 81 are connected.

[0088] On the other hand, when it is determined in step S10 that the current state is a state in which external charging control is being executed or a state in which switching control of the inverter 50 is stopped, the process proceeds to step S16, and an instruction is given to the power supply IC 70 via the setting change unit 80 to set the gate resistor connected to the gate of the control switch 72 to the second gate resistor 111B. More specifically, the changeover switch 83 is operated so that the setting terminal LRT and the second resistor 82 are connected.

[0089] FIG. 14 is a flowchart of the process executed by the power supply IC 70.

[0090] In step S40, it is determined whether the gate resistor connected to the gate of the control switch 72 is designated to be the second gate resistor 111B or the first gate resistor 111A. If it is determined in step S40 that the first gate resistor 111A is designated, the process proceeds to step S41, where the first charge / discharge switch 112A is turned on and the second charge / discharge switch 112B is turned off. Then, switching control of the control switch 72 is performed.

[0091] On the other hand, if it is determined in step S40 that the second gate resistor 111B has been instructed, the process proceeds to step S42, where the second charge / discharge switch 112B is turned on and the first charge / discharge switch 112A is turned off. Then, switching control of the control switch 72 is performed. In this case, the switching speed when the control switch 72 is turned on and the switching speed when it is turned off can be reduced compared to when the process of step S41 is executed. As a result, the level of the harmonic components contained in the noise is reduced, and the noise level can be reduced to or below the allowable value NLjde in the specific frequency range Rfjde.

[0092] <Modification of the third embodiment> The gate switching circuit may be a circuit configured to be able to change the switching speed of either the turn-on or turn-off of the control switch 72, rather than both the turn-on and turn-off.

[0093] The circuit that changes the switching speed of the control switch 72 is not limited to a circuit that changes the resistance value of the gate resistor, but may also be a circuit that changes the power supply voltage of the gate of the control switch 72, or a circuit that changes the ground potential to which the gate charge of the control switch 72 is discharged.

[0094] <Fourth embodiment> The fourth embodiment will be described below with reference to the drawings, focusing on the differences from the first embodiment. In this embodiment, the switching frequency fsw is changed based on information inside the PCU 30, instead of information transmitted from a higher-level ECU 60 provided outside the PCU 30. For this reason, in this embodiment, the PCU 30 is configured so that drive information of a drive circuit 62 is input to a microcomputer 61, as shown in FIG.

[0095] FIG. 16 is a flowchart of the process executed by the microcomputer 61.

[0096] In step S17, it is determined whether or not drive control of the rotating electric machine 40 has not been performed for a predetermined period based on the drive information of the drive circuit 62. Specifically, for example, when the drive information is the gate voltage of the switch SA, it is determined whether or not the gate voltage of the switch SA has been maintained at 0 for a predetermined period. Note that the drive information is not limited to the gate voltage, and may be, for example, a drive command signal input to the drive circuit 62.

[0097] If it is determined in step S17 that the drive control of the rotating electric machine 40 has been performed within the predetermined period, the process proceeds to step S11. On the other hand, if it is determined in step S17 that the drive control of the rotating electric machine 40 has not been performed for the predetermined period, the process proceeds to step S12.

[0098] According to the present embodiment described above, the microcomputer 61 of the PCU 30 can determine whether to change the switching frequency fsw, without depending on information transmitted from the host ECU 60.

[0099] <Fifth embodiment> Hereinafter, the fifth embodiment will be described with reference to the drawings, focusing on the differences from the fourth embodiment. As shown in Fig. 17, when the microcomputer 61 determines, based on the detection value of the current sensor 22, that a charging current flows from the inverter 50 to the high-voltage storage battery 20 by the external charging control, the microcomputer 61 changes the switching frequency fsw.

[0100] FIG. 18 is a flowchart of the process executed by the microcomputer 61.

[0101] In step S18, it is determined whether or not a charging current is flowing from the inverter 50 to the high-voltage storage battery 20, based on the detection value of the current sensor 22. For example, if it is determined that the flow direction of the current flowing through the U- and V-phase conductive paths 53U, 53V detected by the current sensor 22 is toward the inverter 50 side and that the current detected by the current sensor 22 is a DC current, it may be determined that a charging current is flowing.

[0102] If it is determined in step S18 that no charging current is flowing, the process proceeds to step S11. On the other hand, if it is determined in step S18 that a charging current is flowing, the process proceeds to step S12.

[0103] According to the present embodiment described above, when external charging control is performed, the microcomputer 61 of the PCU 30 can determine whether to change the switching frequency fsw, without depending on information transmitted from the host ECU 60.

[0104] Sixth embodiment The sixth embodiment will be described below with reference to the drawings, focusing on the differences from the fourth embodiment. As shown in Fig. 19, the insulated power supply 100 of this embodiment includes an input current detection unit 120 that detects the current flowing from the low-voltage storage battery 21 to the primary coil 71A. The input current detection unit 120 is, for example, a shunt resistor. The power supply IC 70 determines by itself whether to change the switching frequency fsw based on the detection value of the input current detection unit 120.

[0105] FIG. 20 is a flowchart of the process executed by the power supply IC 70.

[0106] In step S50, it is determined whether or not the detected current Ir of the input current detection unit 120 has been below the threshold Ith for a determination period. The determination period is set to a period longer than "1 / fL", for example. The threshold Ith is set to a value close to 0, for example. The process of step S50 is a process for determining that power is not being supplied from the low-voltage storage battery 21 to the primary coil 71A.

[0107] If the determination in step S50 is negative, the process proceeds to step S51, where the switching frequency fsw of the control switch 72 is set to the first frequency fH. Then, switching control of the control switch 72 is performed so that the switching frequency fsw of the control switch 72 becomes the first frequency fH.

[0108] On the other hand, if the result of the determination in step S50 is affirmative, the process proceeds to step S52, where the switching frequency fsw of the control switch 72 is set to the second frequency fL. Then, switching control of the control switch 72 is performed so that the switching frequency fsw of the control switch 72 becomes the second frequency fL.

[0109] According to the present embodiment described above, the power supply IC 70 can determine the change in the switching frequency fsw.

[0110] <Other embodiments> Each of the above embodiments may be modified as follows.

[0111] In the fourth to sixth embodiments, instead of the switching frequency fsw, the output voltage may be changed as described in the second embodiment, or the switching speed may be changed as described in the third embodiment.

[0112] The isolated power supply, which is a switching power supply, is not limited to the flyback type, but may be of other types such as the feedforward type.

[0113] The switches in the inverter are not limited to IGBTs, and may be, for example, N-channel MOSFETs.

[0114] The inverter is not limited to a three-level inverter, but may be a multi-level inverter having four or more levels, or may be a two-level inverter. Also, the inverter and the rotating electric machine are not limited to three-phase inverters, but may be two-phase inverters or four or more phase inverters.

[0115] The rotating electric machine is not limited to one that is star-connected, and may be one that is delta-connected.

[0116] The power source of the inverter and the power storage unit to be externally charged are not limited to a chargeable and dischargeable storage battery, but may be, for example, a capacitor (such as an electric double layer capacitor), or may be both a storage battery and a capacitor.

[0117] The power storage unit may be, for example, a fuel cell. In this case, the power supply device according to the present disclosure is effective when there is a demand for monitoring the state of the inverter switch while the switching control of the inverter is stopped while the vehicle is parked.

[0118] The moving object on which the power supply device is mounted is not limited to a vehicle, but may be, for example, an aircraft or a ship. Also, the power supply device is not limited to a moving object, but may be a stationary device.

[0119] The control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor and a memory programmed to execute one or more functions embodied in a computer program. Alternatively, the control unit and the method described in the present disclosure may be realized by a special-purpose computer provided by configuring a processor with one or more dedicated hardware logic circuits. Alternatively, the control unit and the method described in the present disclosure may be realized by one or more special-purpose computers configured by a combination of a processor and a memory programmed to execute one or more functions and a processor configured with one or more hardware logic circuits. In addition, the computer program may be stored in a computer-readable non-transitory tangible recording medium as instructions executed by the computer. [Explanation of symbols]

[0120] 10...vehicle, 20...high-voltage storage battery, 40...rotating electric machine, 50...inverter, 62...drive circuit, 70...power supply IC, 100...insulated power supply.

Claims

1. A power storage unit (20); An inverter (50) connected to the power storage unit; a rotating electric machine (40) having an armature winding (42U to 42W) connected to the inverter; A drive circuit (62) for driving switches (Su1 to Sw4, SA) included in the inverter; A power supply device applied to a system including: The system includes: A speaker and an AM receiver that detects and demodulates a modulated wave obtained by modulating a carrier wave by AM modulation and outputs the modulated wave to the speaker as an audio signal; is provided, A switching power supply (100) having a power supply control unit (70) and supplying power to the drive circuit by switching control of the power supply control unit, the drive circuit is powered by the switching power supply and has a function of monitoring a state of the switch; the power supply control unit performs a change process to change a switching mode of the switching power supply in a first state in which the power storage unit is charged from an external power supply (15) via the inverter or in which switching control of the switch is stopped, from a switching mode of the switching power supply in a second state in which switching control of the switch is performed to drive the rotating electric machine; The power supply control unit is setting a switching frequency of the switching power supply in the second state to a frequency within a specific frequency range; As the change process, a process is performed to shift the switching frequency of the switching power supply in the first state to a frequency less than a lower limit (RL) of the specific frequency range so that a level of noise generated due to switching control of the switching power supply becomes equal to or less than a permissible value (NLjde) in the specific frequency range; A power supply device, wherein a possible frequency range of AM broadcasts received by the AM receiver is on the higher frequency side than the specific frequency range.

2. The power supply control unit is determining whether a current state is the first state or the second state based on information transmitted from an external control device (60) of the power supply device; The power supply device according to claim 1 , wherein the change process is performed when it is determined that the current state is the first state.

3. The power supply control unit is determining whether a current state is the first state or the second state based on drive information of the drive circuit; The power supply device according to claim 1 , wherein the change process is performed when it is determined that the current state is the first state.

4. the first state is a state in which the power storage unit is charged from the external power supply via the inverter, The system includes a current sensor (22) that detects a charging current flowing from the inverter to the power storage unit, The power supply control unit is determining whether a current state is the first state or the second state based on a detection value of the current sensor; The power supply device according to claim 1 , wherein the change process is performed when it is determined that the current state is the first state.

5. an input current detection unit (120) that detects an input current of the switching power supply and outputs the detected input current to the power supply control unit; The power supply control unit is determining whether a current state is the first state or the second state based on a detection value of the input current detection unit; The power supply device according to claim 1 , wherein the change process is performed when it is determined that the current state is the first state.

6. A power storage unit (20); An inverter (50) connected to the power storage unit; a rotating electric machine (40) having an armature winding (42U to 42W) connected to the inverter; A drive circuit (62) that drives switches (Su1 to Sw4) of the inverter; a switching power supply (100) having a power supply control unit (70) and supplying power to the drive circuit by switching control of the power supply control unit; In a program applied to a system comprising: The system includes: A speaker and an AM receiver that detects and demodulates a modulated wave obtained by modulating a carrier wave by AM modulation and outputs the modulated wave to the speaker as an audio signal; is provided, the drive circuit is powered by the switching power supply and has a function of monitoring a state of the switch; The power supply control unit includes: A process of determining whether a current state is a first state in which the power storage unit is being charged from an external power source (15) via the inverter or a switching control of the switch is stopped, or a second state in which switching control of the switch is being performed to drive the rotating electric machine; a change process for changing a switching mode of the switching power supply when it is determined that the current state is the first state from a switching mode of the switching power supply when it is determined that the current state is the second state; a switching mode of the switching power supply when it is determined that the power supply is in the second state is a mode in which a switching frequency of the switching power supply is set to a frequency within a specific frequency range, the change process is a process of shifting a switching frequency of the switching power supply in the first state to a frequency less than a lower limit (RL) of the specific frequency range so that a level of noise generated in association with switching control of the switching power supply becomes equal to or less than a permissible value (NLjde) in the specific frequency range, A program, wherein a frequency range that the AM broadcasting received by the AM receiver can cover is higher than the specific frequency range.

7. A power storage unit (20), An inverter (50) connected to the power storage unit; a rotating electric machine (40) having an armature winding (42U to 42W) connected to the inverter; A drive circuit (62) that drives switches (Su1 to Sw4) of the inverter; a switching power supply (100) having a power supply control unit (70) and supplying power to the drive circuit by switching control of the power supply control unit; A control method for a system comprising: The system includes: A speaker and an AM receiver that detects and demodulates a modulated wave obtained by modulating a carrier wave by AM modulation and outputs the modulated wave to the speaker as an audio signal; is provided, the drive circuit is powered by the switching power supply and has a function of monitoring a state of the switch; The power supply control unit includes: A process of determining whether a current state is a first state in which the power storage unit is being charged from an external power source (15) via the inverter or a switching control of the switch is stopped, or a second state in which switching control of the switch is being performed to drive the rotating electric machine; a change process for changing a switching mode of the switching power supply when it is determined that the current state is the first state from a switching mode of the switching power supply when it is determined that the current state is the second state; a switching mode of the switching power supply when it is determined that the power supply is in the second state is a mode in which a switching frequency of the switching power supply is set to a frequency within a specific frequency range, the change process is a process of shifting a switching frequency of the switching power supply in the first state to a frequency less than a lower limit (RL) of the specific frequency range so that a level of noise generated in association with switching control of the switching power supply becomes equal to or less than a permissible value (NLjde) in the specific frequency range, A control method, wherein a possible frequency range of AM broadcasts received by the AM receiver is higher than the specific frequency range.

Images