WO2024089865A1 - 電力変換装置、充電装置および制御方法 - Google Patents

電力変換装置、充電装置および制御方法 Download PDF

Info

Publication number
WO2024089865A1
WO2024089865A1 PCT/JP2022/040300 JP2022040300W WO2024089865A1 WO 2024089865 A1 WO2024089865 A1 WO 2024089865A1 JP 2022040300 W JP2022040300 W JP 2022040300W WO 2024089865 A1 WO2024089865 A1 WO 2024089865A1
Authority
WO
WIPO (PCT)
Prior art keywords
voltage
switching
phase difference
bridge circuit
coil
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Ceased
Application number
PCT/JP2022/040300
Other languages
English (en)
French (fr)
Japanese (ja)
Inventor
知滉 前田
圭司 田代
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Sumitomo Wiring Systems Ltd
AutoNetworks Technologies Ltd
Sumitomo Electric Industries Ltd
Original Assignee
Sumitomo Wiring Systems Ltd
AutoNetworks Technologies Ltd
Sumitomo Electric Industries Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sumitomo Wiring Systems Ltd, AutoNetworks Technologies Ltd, Sumitomo Electric Industries Ltd filed Critical Sumitomo Wiring Systems Ltd
Priority to JP2024552630A priority Critical patent/JP7823764B2/ja
Priority to PCT/JP2022/040300 priority patent/WO2024089865A1/ja
Publication of WO2024089865A1 publication Critical patent/WO2024089865A1/ja
Anticipated expiration legal-status Critical
Ceased legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02M—APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF
    • H02M3/00—Conversion of DC power input into DC power output
    • H02M3/22—Conversion of DC power input into DC power output with intermediate conversion into AC
    • H02M3/24—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters
    • H02M3/28—Conversion of DC power input into DC power output with intermediate conversion into AC by static converters using discharge tubes with control electrode or semiconductor devices with control electrode to produce the intermediate AC

Definitions

  • This disclosure relates to a power conversion device, a charging device, and a control method.
  • Power conversion devices are used in various electrical devices and electrical equipment.
  • vehicles such as PHEVs (Plug-in Hybrid Electric Vehicles) or EVs (Electric Vehicles) are equipped with an on-board charger, a DC/DC converter, and multiple power conversion units.
  • These power conversion devices convert AC power from the power grid into DC power to charge the on-board battery.
  • the output voltage of the on-board battery is converted to an appropriate voltage and supplied to each device inside the vehicle.
  • Patent Document 1 discloses an isolated bidirectional DC/DC converter that can achieve high efficiency over a wide range of transmission power.
  • This DC/DC converter performs phase difference control in the high output power range, and performs burst control in the low output range as a countermeasure against reduced transmission efficiency.
  • the burst control described in Patent Document 1 performs intermittent operation by switching the DC/DC converter for a period of ⁇ +2 ⁇ m, where m is a real number that is a natural number multiple of 0.5, and n is a real number, and stopping the switching of the DC/DC converter for a period of 2 ⁇ n.
  • burst control the transmission power is adjusted by changing n. In other words, the transmission power is adjusted by changing the period during which switching is stopped.
  • a power conversion device includes a transformer including a first coil and a second coil, a first bridge circuit including a plurality of first switching elements and connected to the first coil, and a second bridge circuit including a plurality of second switching elements and connected to the second coil, the first bridge circuit generates a first AC voltage and supplies it to the first coil, the second bridge circuit converts and outputs a second AC voltage generated in the second coil, and switches between phase difference control that adjusts the phase difference between the second AC voltage and the first AC voltage and burst control that keeps the phase difference constant, fixes one control cycle, and adjusts the period during which the first AC voltage is supplied, depending on the transmission power.
  • FIG. 1 is a graph showing changes in voltage and current when a switching element is in an ON state.
  • FIG. 2 is a circuit diagram showing a configuration of the power conversion device according to the first embodiment of the present disclosure.
  • FIG. 3 is a waveform diagram showing control signals for each switching element shown in FIG.
  • FIG. 4 is a circuit diagram showing a current flow in the first mode of the first bridge circuit shown in FIG.
  • FIG. 5 is a circuit diagram showing a current flow in the second mode of the first bridge circuit shown in FIG.
  • FIG. 6 is a circuit diagram showing a current flow in the second bridge circuit shown in FIG. 2 in the third mode.
  • FIG. 7 is a circuit diagram showing a current flow in the fourth mode of the second bridge circuit shown in FIG.
  • FIG. 1 is a graph showing changes in voltage and current when a switching element is in an ON state.
  • FIG. 2 is a circuit diagram showing a configuration of the power conversion device according to the first embodiment of the present disclosure.
  • FIG. 3 is a waveform
  • FIG. 8 is a graph showing changes in voltage and current in the power conversion device shown in FIG.
  • FIG. 9 is a circuit diagram showing a current flow when switching from the first mode to the second mode in the first bridge circuit shown in FIG. 2 in the case of soft switching.
  • FIG. 10 is a circuit diagram showing a current flow different from that in FIG. 3 in the first mode of the first bridge circuit shown in FIG.
  • FIG. 11 is a circuit diagram showing a current flow when switching from the first mode to the second mode in the first bridge circuit shown in FIG. 2 in the case of hard switching.
  • FIG. 12 is a graph showing changes in voltage and current when the switching operation in the power conversion device shown in FIG. 2 is hard switching.
  • FIG. 13 is a flowchart showing the operation executed by the control unit shown in FIG. FIG.
  • FIG. 14 is a graph showing a voltage waveform when the output power is 100% in burst control.
  • FIG. 15 is a graph showing a voltage waveform when the output power is less than 100% in burst control.
  • FIG. 16 is a graph showing changes in phase difference and burst ratio caused by switching between phase difference control and burst control.
  • FIG. 17 is a diagram showing a simulation result when only the phase difference control is executed.
  • FIG. 18 is a diagram showing a simulation result when switching between phase difference control and burst control.
  • FIG. 19 is a graph showing the correspondence between the voltage waveform and the current waveform in burst control.
  • FIG. 20 is a block diagram showing a charging device according to the second embodiment of the present disclosure.
  • phase difference control In phase difference control, the smaller the output power from the power conversion device, the smaller the phase difference must be. If the phase difference is small, the switching operation of the switching elements constituting the bridge circuit included in the power conversion device becomes hard switching, which causes a problem of power loss during switching (hereinafter referred to as switching loss). It is preferable to take switching loss into consideration in the on/off control of the switching elements.
  • the switching loss is obtained by integrating the product of the voltage and the current over the transition period. Assume that a FET (Field Effect Transistor) is used as the switching element.
  • any of the switching elements constituting the power conversion device changes from the off state to the on state, if no current flows through the parasitic diode in the off state of the switching element, a voltage is generated between the source and drain of the switching element, and switching loss occurs (i.e., hard switching).
  • switching loss occurs (i.e., hard switching).
  • a current flows through the parasitic diode in the off state of the switching element the voltage between the source and drain of the switching element is 0, and no switching loss occurs.
  • This type of switching is called soft switching. Note that 0 does not mean mathematical zero, but is a value that can be interpreted as substantially zero, and also includes the value of the forward voltage of the parasitic diode.
  • Patent Document 1 discloses performing burst control in the low output region.
  • the disclosed burst control adjusts the transmission power by varying the period for which switching is stopped by changing n. This causes a problem in that it is difficult to adjust the transmission power because one cycle of intermittent operation changes with the change in n.
  • the timing for starting switching also differs from cycle to cycle as one cycle of intermittent operation changes. This necessitates adjustments to match the timing each time, which complicates the control.
  • the present disclosure aims to provide a power conversion device, a charging device, and a control method that can reduce switching losses through simple control even when the output power is small.
  • a power conversion device includes a transformer including a first coil and a second coil, a first bridge circuit including a plurality of first switching elements and connected to the first coil, and a second bridge circuit including a plurality of second switching elements and connected to the second coil, the first bridge circuit generates a first AC voltage and supplies it to the first coil, the second bridge circuit converts and outputs a second AC voltage generated in the second coil, and switches between phase difference control that adjusts the phase difference between the first AC voltage and the second AC voltage and burst control that keeps the phase difference constant and fixes one control cycle to adjust the period during which the first AC voltage is supplied, depending on the transmission power.
  • each switching element constituting the power conversion device can be soft-switched, the switching loss due to hard switching can be reduced, and overheating and failure can be suppressed.
  • the power conversion device performs phase difference control if the transmission power is greater than a predetermined threshold, and performs burst control if the transmission power is equal to or less than the threshold. This makes it easy to switch between phase difference control and burst control.
  • the threshold value is greater than a value corresponding to a lower limit of the phase difference
  • the lower limit is the value of the phase difference when the operation of at least some of the first switching elements and the second switching elements changes from soft switching to hard switching. This makes it possible to reliably perform soft switching on each switching element.
  • the burst period which is the period during which the first AC voltage is supplied, is changed based on a predetermined period. This makes it possible to output the desired output power.
  • N and Nb are natural numbers, and N is greater than Nb.
  • the predetermined period is equal to N times the period of the first AC voltage, and during the burst period, the first AC voltage is continuously input to the first bridge circuit, and the burst period is equal to Nb times the period. This makes it easy to perform burst control.
  • the frequency of the first AC voltage is constant during burst control. This makes it easier to perform burst control.
  • a charging device includes any one of the power conversion devices (1) to (6) above, and outputs the DC voltage converted by the second bridge circuit as charging power. This allows each switching element constituting the power conversion device to perform soft switching operation even when the output power is small, reducing switching losses due to hard switching and suppressing overheating and failure.
  • the charging device further includes an AC/DC converter, and the DC voltage output from the AC/DC converter is input to the first bridge circuit. This makes it possible to realize a charging device that operates using AC power supplied from an external source (e.g., commercial AC power).
  • an external source e.g., commercial AC power
  • the charging device is fixedly installed and supplies power to a storage battery mounted in an external device. This makes it possible to realize a charging device that can charge a storage battery mounted in an external device (e.g., a vehicle, etc.) using commercial AC power.
  • the charging power is changed according to the capacity of the storage battery to which the charging power is supplied. This allows the storage battery to be appropriately charged.
  • a control method is a control method for a power conversion device including a transformer including a first coil and a second coil, a first bridge circuit including a plurality of first switching elements and connected to the first coil, and a second bridge circuit including a plurality of second switching elements and connected to the second coil, the control method including the steps of causing the first bridge circuit to generate a first AC voltage and supply it to the first coil, causing the second bridge circuit to convert and output the second AC voltage generated in the second coil, a phase difference control step of adjusting the phase difference between the first AC voltage and the second AC voltage, a burst control step of adjusting the period during which the first AC voltage is supplied according to the output power by fixing the phase difference and one control cycle, and a step of switching between the phase difference control step and the burst control step according to the transmission power.
  • the control method including the steps of causing the first bridge circuit to generate a first AC voltage and supply it to the first coil, causing the second bridge circuit to convert and output the second AC voltage generated in the second coil,
  • the power conversion device 100 is an isolated power conversion device including a transformer, that is, a DC/DC converter of a dual active bridge (DAB) system.
  • the power conversion device 100 includes a first bridge circuit 102, a transformer 104, a second bridge circuit 106, and a control unit 110.
  • the power conversion device 100 may include a capacitor C1, a capacitor C2, and a capacitor C3, and a choke coil L3.
  • the first bridge circuit 102 is a DC/AC conversion circuit and includes switching element Q1, switching element Q2, switching element Q3, and switching element Q4.
  • Switching elements Q1 to Q4 are bridge-connected to form a full-bridge circuit.
  • Switching elements Q1 to Q4 are composed of, for example, FETs.
  • Figure 2 shows the parasitic diodes (i.e., body diodes) formed inside the FETs.
  • the second bridge circuit 106 is an AC/DC conversion circuit and includes switching element Q5, switching element Q6, switching element Q7, and switching element Q8.
  • Switching elements Q5 to Q8 are bridge-connected to form a full-bridge circuit.
  • Switching elements Q5 to Q8 are formed, for example, from FETs.
  • the transformer 104 includes a core 120, a first coil 122 and a second coil 124 wound around the core 120, and a first inductor L1 and a second inductor L2.
  • the transformer 104 does not necessarily have to include the core 120.
  • the first coil 122 functions as the primary coil of the transformer 104
  • the second coil 124 functions as the secondary coil of the transformer 104.
  • the first inductor L1 and the second inductor L2 may be any inductive components, and in FIG. 2, the first inductor L1 and the second inductor L2 utilize the leakage inductance of the transformer 104 and are illustrated as being included in the transformer 104.
  • the first inductor L1 and the second inductor L2 may be separate coils from the first coil 122 and the second coil 124 of the transformer 104.
  • the output terminal of the first bridge circuit 102 is connected to both terminals of the first inductor L1 and the first coil 122, which are connected in series.
  • the input terminal of the second bridge circuit 106 is connected to the second inductor L2 and the second coil 124, which are connected in series.
  • a DC voltage E1 is supplied between the nodes N1 and N2 constituting the input section 130.
  • the DC voltage E1 is input to the first bridge circuit 102 via the capacitor C1.
  • the control section 110 controls the on and off of each of the switching elements Q1 to Q4, so that the first bridge circuit 102 converts the DC voltage E1 input between the nodes N1 and N2 into an AC voltage and outputs it as an AC voltage V1 between the nodes N5 and N6.
  • the AC voltage V1 is supplied to the first coil 122 of the transformer 104.
  • the AC voltage generated in the second coil 124 is input to the second bridge circuit 106 as the AC voltage V2 between the nodes N7 and N8.
  • the AC voltage V2 is converted to a DC voltage by the control unit 110 controlling the on and off of the switching elements Q5 to Q8, and is output from the second bridge circuit 106.
  • the output voltage of the second bridge circuit 106 is smoothed by the choke coil L3, the capacitors C2 and C3, and is output as a DC voltage E2 between the nodes N3 and N4 that constitute the output unit 132. That is, the power conversion device 100 functions as a DC/DC converter as described above.
  • the control unit 110 includes a CPU (Central Processing Unit) 112, a memory 114, and an I/F unit (interface unit) 116.
  • the memory 114 stores a program executed by the CPU 112.
  • the I/F unit 116 under the control of the CPU 112, outputs a signal (i.e., the gate voltage of each switching element) for controlling the on and off of each switching element constituting the first bridge circuit 102 and the second bridge circuit 106, as described above.
  • a power measuring device e.g., a sensor
  • the I/F unit 116 receives measured values at the input unit 130 and the output unit 132 and stores them in the memory 114.
  • the I/F unit 116 also receives instructions such as a target value of the output power from outside the power conversion device 100 and stores them in the memory 114.
  • the stored measurements and instructions e.g., target values for output power
  • the CPU 112 executes these processes by executing programs read from the memory 114.
  • Switching elements Q1 to Q8 are controlled by a phase shift method. Referring to FIG. 3, switching elements Q1 to Q8 are all controlled with the same period T. Switching elements Q1 and Q4 are turned on at the same timing and turned off at the same timing. Switching elements Q2 and Q3 are also controlled on and off at the same timing. Switching elements Q1 and Q2 are alternately turned on with a duty of 50%, and switching elements Q3 and Q4 are also alternately turned on with a duty of 50%. In other words, the pulse width of the control signal is the same. Note that “same" means that it is within a specified error range.
  • switching element Q5 and switching element Q8 are controlled to be turned on and off at the same timing.
  • Switching element Q6 and switching element Q7 are also controlled to be turned on and off at the same timing.
  • Switching element Q5 and switching element Q6 are alternately turned on with a duty of 50%, and switching element Q7 and switching element Q8 are also alternately turned on with a duty of 50%.
  • switching element Q5 is turned on with a phase difference of time Tp with respect to switching element Q1.
  • the phase difference of time Tp is expressed in degrees as 2 ⁇ Tp/T (rad). As time Tp is treated as a phase difference in this way, it will be referred to as phase difference Tp below.
  • the operation of the power conversion device 100 will be specifically described with reference to Figures 4 to 8.
  • the first bridge circuit 102 and the second bridge circuit 106 each operate in two modes.
  • the two operating modes of the first bridge circuit 102 are a first mode m1 and a second mode m2
  • the two operating modes of the second bridge circuit 106 are a third mode m3 and a fourth mode m4.
  • FIG. 4 shows the circuit to the left of the first coil 122 of the transformer 104 in FIG. 2.
  • the switching elements Q1 and Q4 are turned on, and the switching elements Q2 and Q3 are turned off. This causes a current to flow as shown by the arrows. That is, the current flows through the switching element Q1, the first inductor L1, the first coil 122, and the switching element Q4.
  • FIG. 5 shows the circuit to the left of the first coil 122 of the transformer 104 in FIG. 2.
  • the switching elements Q1 and Q4 are turned off, and the switching elements Q2 and Q3 are turned on. This causes a current to flow as shown by the arrows. That is, the current flows through the switching element Q3, the first inductor L1, the first coil 122, and the switching element Q4.
  • FIG. 6 shows the circuit to the right of the second coil 124 of the transformer 104 in FIG. 2.
  • the switching elements Q5 and Q8 are turned on, and the switching elements Q6 and Q7 are turned off. This causes a current to flow as shown by the arrows. That is, the current flows through the switching element Q8, the second inductor L2, the second coil 124, and the switching element Q5.
  • FIG. 7 shows the circuit to the right of the second coil 124 of the transformer 104 in FIG. 2.
  • the switching elements Q5 and Q8 are turned off, and the switching elements Q6 and Q7 are turned on. This causes a current to flow as shown by the arrows. That is, the current flows through the switching element Q6, the second inductor L2, the second coil 124, and the switching element Q7.
  • the half cycle (T/2) is divided into four periods with reference to FIG. 8.
  • the first bridge circuit 102 operates in the first mode m1, and the second bridge circuit 106 operates in the fourth mode m4.
  • the first bridge circuit 102 operates in the first mode m1
  • the second bridge circuit 106 operates in the third mode m3.
  • the first bridge circuit 102 operates in the second mode m2
  • the second bridge circuit 106 operates in the third mode m3.
  • the fourth period following the third period the first bridge circuit 102 operates in the second mode m2, and the second bridge circuit 106 operates in the fourth mode m4.
  • the output voltage of the first bridge circuit 102 i.e., AC voltage V1
  • the input voltage of the second bridge circuit 106 i.e., AC voltage V2
  • the AC voltage V3 of the first inductor L1 change as shown in FIG. 8.
  • the positive or negative value of the current I1 i.e., the current values at points A, B, C, and D
  • the current I1 is positive when it flows in the direction shown by the arrow in FIG. 2 (i.e., to the right), and negative when it flows in the opposite direction (i.e., to the left).
  • the first mode m1 may be in a state as shown in FIG. 10, for example.
  • the current I1 is in the opposite direction to the direction shown in FIG. 4 (i.e., the current I1 is negative).
  • the state as shown in FIG. 11 is reached. Referring to FIG. 11, the switching element Q1 and the switching element Q4 that were on in the first mode m1 are turned off. The switching element Q2 and the switching element Q3 are maintained off.
  • the direction of the current flowing through the first inductor L1 is maintained, so that the current flows as shown by the arrow. That is, the current flows through the parasitic diode of the switching element Q4, the first inductor L1 and the first coil 122, and the parasitic diode of the switching element Q1, and no current flows through the parasitic diode of the switching element Q2 and the parasitic diode of the switching element Q3.
  • the first bridge circuit 102 operates in the second mode m2, so that the switching elements Q2 and Q3 are turned on. Therefore, the switching that turns on the switching elements Q2 and Q3 is hard switching.
  • the soft switching condition when the first bridge circuit 102 switches from the first mode m1 to the second mode m2 is that the current I1 is positive.
  • the soft switching condition when the first bridge circuit 102 switches from the second mode m2 to the first mode m1 is that the current I1 is negative.
  • the soft switching condition when the second bridge circuit 106 switches from the third mode m3 to the fourth mode m4 is that the current I1 is negative.
  • the soft switching condition when the second bridge circuit 106 switches from the fourth mode m4 to the third mode m3 is that the current I1 is positive.
  • the current I1 shown in FIG. 8 satisfies the soft switching conditions at all timings when the first bridge circuit 102 and the second bridge circuit 106 switch modes. Therefore, in this case, phase difference control with reduced switching loss is realized.
  • the phase difference Tp is controlled to be reduced, for example, as shown in FIG. 12.
  • points A, B, C, and D shown in FIG. 8 change to points A', B', C', and D'. That is, the current I1 at point B' becomes negative, and the current I1 at point D' becomes positive.
  • Point B' is the timing when the second bridge circuit 106 switches from the fourth mode m4 to the third mode m3, and since the current I1 is negative, the soft switching conditions (i.e., the current I1 is positive) when switching from the fourth mode m4 to the third mode m3 are not satisfied, and hard switching occurs.
  • point D' is the timing when the second bridge circuit 106 switches from the third mode m3 to the fourth mode m4, and since the current I1 is positive, the soft switching condition (i.e., the current I1 is negative) when switching from the third mode m3 to the fourth mode m4 is not met, and hard switching occurs.
  • step 300 the CPU 112 reads the target value of the output power and the initial value of the phase difference control from the memory 114, and starts the phase difference control. After that, control proceeds to step 302.
  • the target value of the output power is received by the I/F unit 116 as an instruction from outside the control unit 110 as described above, and is stored in the memory 114.
  • the initial value of the phase difference control includes the period T and the initial value of the phase difference Tp. Note that since the output power can be calculated by the following formula, the initial value of the phase difference Tp may be calculated from the target value of the output power.
  • P is the output power of the power conversion device 100
  • L is the total value of the inductance of the first inductor L1 and the second inductor L2 of the transformer 104
  • n1 and n2 are the number of turns of the first coil 122 and the second coil 124 of the transformer 104, respectively.
  • E1 and E2 are the input voltage (i.e., DC voltage E1) and the output voltage (i.e., DC voltage E2) of the power conversion device 100 described above, respectively.
  • the power difference is within the predetermined range.
  • step 304 the CPU 112 determines whether the current phase difference Tp is equal to or less than the threshold value Tpth. If it is determined that Tp ⁇ Tpth, control proceeds to step 306. Otherwise (i.e., Tp>Tpth), control proceeds to step 308.
  • step 306 the CPU 112 stops the phase difference control and starts burst control.
  • the phase difference Tp at this time is used as the phase difference for switching control in burst control.
  • a threshold value Tpth may be used as the phase difference Tp for burst control.
  • each switching element is operated intermittently.
  • switching elements Q1 to Q8 are continuously switched at a constant period T.
  • AC voltage V1 and AC voltage V2 are, for example, as shown in FIG. 14, which is the maximum output state in burst control (i.e., 100% output power).
  • the voltage waveform in FIG. 14 corresponds to the voltage waveform shown in FIG. 8 and is shown for a longer period than FIG. 8.
  • a period Ts is provided in which the switching operation is stopped from the state shown in FIG. 14, as shown in FIG. 15.
  • the period in which the stop period Ts is repeated is represented by Ta.
  • the number of oscillations of the voltage waveform during the period Ta (hereinafter referred to as the reference burst number) N is shown in parentheses.
  • the period in which the voltage is output is represented by Tb, and the corresponding number of oscillations of the voltage waveform (hereinafter referred to as the burst number) Nb is shown in parentheses.
  • the output power is (Nb/N) x 100 (%) of the output power in the state shown in FIG. 14 (i.e., output power 100%).
  • the switching element is switched by the phase difference Tp, which realizes soft switching, so switching losses are reduced.
  • step 308 the CPU 112 changes the phase difference Tp from its current value. For example, if the (target value-measured power) calculated in step 302 is positive, the CPU 112 increases the phase difference Tp from its current value. For example, the CPU 112 adds a predetermined value ⁇ Tp to the current phase difference Tp to obtain a new phase difference Tp (i.e., Tp+ ⁇ Tp). If the (target value-measured power) is negative, the CPU 112 decreases the phase difference Tp from its current value.
  • the CPU 112 subtracts a predetermined value ⁇ Tp from the current phase difference Tp to obtain a new phase difference Tp (i.e., Tp- ⁇ Tp).
  • ⁇ Tp a predetermined value
  • the CPU 112 uses the new phase difference Tp to control the switching of the switching elements Q1 to Q8. Thereafter, the control returns to step 302.
  • Tp>Tpth the switching of the switching elements Q1 to Q8 is controlled by phase difference control.
  • step 310 the CPU 112 determines whether the output power is equal to the target value, as in step 302. If it is determined that the power difference between the measured power and the target value (i.e.,
  • the CPU 112 changes the burst count Nb. For example, if the (target value-measured power) calculated in step 310 is positive, the CPU 112 increases the burst count Nb from its current value. For example, the CPU 112 adds a predetermined value ⁇ Nb to the current burst count Nb and sets the resulting value (i.e., Nb+ ⁇ Nb) as the new burst count Nb. If the (target value-measured power) is negative, the CPU 112 decreases the burst count Nb from its current value.
  • the CPU 112 subtracts a predetermined value ⁇ Nb from the current burst count Nb and sets the resulting value (i.e., Nb- ⁇ Nb) as the new burst count Nb.
  • the CPU 112 uses the new burst count Nb to operate switching elements Q1 to Q8 intermittently. Thereafter, control returns to step 310.
  • step 314 the CPU 112 determines whether the target value of the output power has been changed. Specifically, the CPU 112 determines whether a target value different from the current target value has been received as a new command from outside. If it is determined that the target value has been changed (i.e., a new target value has been received), control returns to step 300, and the above-mentioned processing is executed using the new target value. If it is determined that the target value has not been changed (i.e., a new target value has not been received), control proceeds to step 316.
  • step 316 the CPU 112 determines whether or not to end the control of the switching elements. If it is determined that the control should be ended, the CPU 112 ends the program. If not, control returns to step 314.
  • the instruction to end is given, for example, by stopping the power supply for operating the power conversion device 100.
  • the control unit 110 can switch between phase difference control and burst control to operate the power conversion device 100.
  • the horizontal axis represents output power
  • the solid line represents changes in phase difference Tp (see the vertical axis on the right)
  • the dashed line represents changes in burst ratio (see the vertical axis on the left).
  • the vertical axis on the right represents the phase difference threshold value Tpth used for the determination in step 304 of FIG. 13.
  • the threshold value Tpth is the lower limit of the phase difference for which phase difference control is executed. In other words, the phase difference is not set to a value smaller than Tpth.
  • FIG. 16 shows the maximum and minimum values Pmax and Pmin of the output power, and the output power threshold Pth corresponding to the phase difference threshold Tpth.
  • the output power threshold Pth is set to 100% of the output power in burst control, and the burst ratio (i.e., (Nb/N) x 100(%)) is reduced (i.e., the number of bursts Nb is reduced).
  • phase difference control is stopped and burst control is performed.
  • burst control the number of bursts Nb (i.e., the burst ratio) is changed to achieve the target output power.
  • burst control the phase difference at which soft switching is achieved is maintained and switching losses are reduced.
  • the target value of the output power increases to above the threshold value Pth while burst control is being performed, i.e., if the number of bursts Nb>N
  • burst control is stopped and phase difference control is performed.
  • phase difference control the phase difference Tp is changed to achieve the target output power. In phase difference control, soft switching is achieved and switching losses are reduced.
  • each switching element constituting the power conversion device 100 can be operated in soft switching mode, reducing switching losses due to hard switching and suppressing overheating and failures.
  • phase difference Tp is compared with a predetermined threshold value Tpth, and if the phase difference Tp is greater than the predetermined threshold value Tph, phase difference control is performed, and if the phase difference Tp is equal to or less than the threshold value Tpth, burst control is performed. This makes it easy to switch between phase difference control and burst control.
  • phase difference threshold value Tpth is set to be equal to or greater than the lower limit value Tpmin of the phase difference (i.e. Tpth ⁇ Tpmin).
  • the lower limit value Tpmin of the phase difference may be the phase difference when the operation of at least some of the switching elements Q1 to Q8 changes from soft switching to hard switching. This makes it possible to reliably perform soft switching operation for each switching element.
  • the burst period i.e., period Tb
  • a predetermined period i.e., cycle Ta
  • N and Nb are natural numbers, and N is greater than Nb, the predetermined period (i.e., period Ta) is equal to N times the period T of the AC voltage V1, the AC voltage V1 is continuously input to the first bridge circuit 102 during the predetermined period, and the burst period (i.e., period Tb) is equal to Nb times the period T. This makes it easy to perform burst control.
  • the period T of the AC voltage V1 is constant, i.e., the frequency is constant. This makes it easier to perform burst control.
  • FIG. 17 shows an example of a simulation result when the switching elements constituting the power conversion device 100 are controlled by phase difference control.
  • the horizontal axis represents the output voltage E2
  • the vertical axis represents the output power.
  • the output voltage E2 varies from a minimum value E2min to a maximum value E2max.
  • the output power varies from a minimum value Pmin to a maximum value Pmax.
  • the switching operation of the switching elements Q1 to Q8 is soft switching.
  • the switching operation of the switching elements Q1 to Q8 is hard switching.
  • the hard switching region is separated into two regions, but this is not limited to this.
  • the shape of the hard switching region changes depending on the simulation conditions.
  • FIG. 18 shows the results of a simulation in which the switching elements constituting the power conversion device 100 are controlled by switching between phase difference control and burst control as described above.
  • the meanings of the vertical and horizontal axes in FIG. 18 and the displayed range are the same as those in FIG. 17.
  • the dashed line sloping upward to the right represents a state in which the phase difference Tp is a constant value (i.e., when the phase difference Tp is a constant value, the above equation 1 becomes an equation in which P is proportional to the DC voltage E2).
  • phase difference control is performed
  • burst control burst control is performed. Therefore, as shown in FIG. 18, soft switching is achieved in the switching control of switching elements Q1 to Q8 in all regions. Therefore, switching losses are reduced.
  • burst control hard switching occurs immediately after the start of the burst period. For example, as shown in FIG. 19, in burst control, hard switching occurs for a short time immediately after switching control is started from a state in which switching control was stopped (see region 200 in FIG. 19). When switching control is repeated thereafter, soft switching occurs (see region 202 in FIG. 19). Therefore, although the repetition period Ta of the period Ts in which the voltage output is stopped, that is, the reference burst number N, is arbitrary, it is preferable to use a larger value so that switching control continues until soft switching occurs. By using a large value as the reference burst number N, it is possible to avoid maintaining hard switching and reduce switching losses. However, if N is made too large, there are disadvantages such as an increase in the size of the output filter, so it is preferable that N is, for example, 100 or less (N ⁇ 100).
  • a charging device 220 according to a second embodiment of the present disclosure includes a DC/DC converter 222, an AC/DC converter 224, and a control unit 226.
  • the charging device 220 is fixedly installed, for example, in a home or the like.
  • the DC/DC converter 222 is configured by the power conversion device 100 shown in FIG. 2.
  • the AC/DC converter 224 converts AC power supplied from an AC power source into DC power (specifically, the DC voltage E2 shown in FIG. 2) and outputs the converted power.
  • the voltage input to the AC/DC converter 224 is, for example, an AC voltage (for example, 110V) supplied from a commercial power source.
  • the AC/DC converter 224 can be realized, for example, by a bridge circuit similar to the second bridge circuit 106 shown in FIG. 2.
  • the output section of the AC/DC converter 224 and the input section of the DC/DC converter 222 are connected via a capacitor 228. 2, and controls the on/off of switching elements included in the DC/DC converter 222 and the AC/DC converter 224.
  • the automobile 230 includes a storage battery, and is, for example, a PHEV or EV.
  • the control unit 110 controls the switching elements of the DC/DC converter 222 and the AC/DC converter 224 so that the DC/DC converter 222 outputs an appropriate DC voltage (i.e., DC voltage E2) for charging the storage battery included in the automobile 230.
  • DC voltage E2 DC voltage
  • the charging device 220 controls the DC/DC converter 222 as shown in FIG. 13. This allows the switching elements constituting the DC/DC converter 222 to perform soft switching operation even when the charging power is small, reducing losses due to hard switching and suppressing overheating and failure.
  • the above describes the case where a storage battery included in a vehicle is charged, but this is not limited to this.
  • the charging device 220 may also be suitable for charging a storage battery included in an external device other than a vehicle.
  • the charging device 220 includes the AC/DC converter 224, and the DC voltage output from the AC/DC converter 224 is input to the DC/DC converter 222. This makes it possible to realize a charging device that operates using AC power supplied from an external source (e.g., commercial AC power).
  • an external source e.g., commercial AC power
  • the charging device 220 is fixedly installed and supplies power to a storage battery mounted in an external device. This makes it possible to realize a charging device that can charge a storage battery mounted in an external device (such as a vehicle) using commercial AC power.
  • the charging power supplied from the charging device 220 is changed according to the capacity of the storage battery to which the charging power is supplied. This allows the storage battery to be appropriately charged.
  • the duty of the control signal for switching element Q1 to switching element Q8 is 50%, but this is not limiting. As long as the switching elements connected in series (e.g., switching element Q1 and switching element Q2) are not turned on at the same time but are turned on alternately, the duty may be a value other than 50% (e.g., 48%).
  • the switching elements constituting the power conversion device 100 are N-type FETs (see FIG. 2), but this is not limited to this.
  • a full bridge circuit constituting the power conversion device may be formed using P-type FETs.
  • Reference Signs List 100 Power conversion device 102 First bridge circuit 104 Transformer 106 Second bridge circuit 110, 226 Control unit 112 CPU 114 Memory 116 I/F section 120 Core 122 First coil 124 Second coil 130 Input section 132 Output section 200, 202 Area 220 Charging device 222 DC/DC converter 224 AC/DC converter 228, C1, C2, C3 Capacitor 230 Automobile 300, 302, 304, 306, 308, 310, 312, 314, 316 Steps A, A', B, B', C, C', D, D' Points E1, E2 DC voltages Emax, Pmax Maximum values Emin, Pmin Minimum values I0, I1 Current L1 First inductor L2 Second inductor L3 Choke coils m1, m2, m3, m4 Modes N1, N2, N3, N4, N5, N6, N7, N8 Node N Reference burst count Nb Burst count Pth, Tpth Threshold Q1, Q2, Q3, Q4, Q5, Q6, Q7,

Landscapes

  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Dc-Dc Converters (AREA)
PCT/JP2022/040300 2022-10-28 2022-10-28 電力変換装置、充電装置および制御方法 Ceased WO2024089865A1 (ja)

Priority Applications (2)

Application Number Priority Date Filing Date Title
JP2024552630A JP7823764B2 (ja) 2022-10-28 2022-10-28 電力変換装置、充電装置および制御方法
PCT/JP2022/040300 WO2024089865A1 (ja) 2022-10-28 2022-10-28 電力変換装置、充電装置および制御方法

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2022/040300 WO2024089865A1 (ja) 2022-10-28 2022-10-28 電力変換装置、充電装置および制御方法

Publications (1)

Publication Number Publication Date
WO2024089865A1 true WO2024089865A1 (ja) 2024-05-02

Family

ID=90830409

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2022/040300 Ceased WO2024089865A1 (ja) 2022-10-28 2022-10-28 電力変換装置、充電装置および制御方法

Country Status (2)

Country Link
JP (1) JP7823764B2 (https=)
WO (1) WO2024089865A1 (https=)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2026023374A1 (ja) * 2024-07-26 2026-01-29 株式会社Soken 電力変換器、電力変換器の制御装置、プログラム、及び電力変換器の制御方法

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013252000A (ja) * 2012-06-01 2013-12-12 Tdk Corp 双方向ｄｃｄｃコンバータ
JP2017130997A (ja) * 2016-01-18 2017-07-27 国立大学法人東京工業大学 絶縁型の双方向ｄｃ／ｄｃコンバータおよびその制御方法
JP6747569B1 (ja) * 2019-11-21 2020-08-26 富士電機株式会社 電力変換装置、制御方法、および制御プログラム

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013252000A (ja) * 2012-06-01 2013-12-12 Tdk Corp 双方向ｄｃｄｃコンバータ
JP2017130997A (ja) * 2016-01-18 2017-07-27 国立大学法人東京工業大学 絶縁型の双方向ｄｃ／ｄｃコンバータおよびその制御方法
JP6747569B1 (ja) * 2019-11-21 2020-08-26 富士電機株式会社 電力変換装置、制御方法、および制御プログラム

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2026023374A1 (ja) * 2024-07-26 2026-01-29 株式会社Soken 電力変換器、電力変換器の制御装置、プログラム、及び電力変換器の制御方法

Also Published As

Publication number Publication date
JPWO2024089865A1 (https=) 2024-05-02
JP7823764B2 (ja) 2026-03-04

Similar Documents

Publication Publication Date Title
JP6003932B2 (ja) 電力変換装置及びその起動方法
US8587252B2 (en) System and method for digital control of a DC/DC power-converter device, in particular for automotive applications
CN103503292B (zh) 电力变换装置以及具备该电力变换装置的车载电源装置
JP6102898B2 (ja) 電力変換装置
JP2016019463A (ja) パルス幅変調共振コンバータおよびこれを利用した車両用充電器
JP5958487B2 (ja) 電力変換装置及び電力変換方法
US9744856B2 (en) Power conversion apparatus
JP6996661B1 (ja) 電力変換装置、それを含む車両及び制御方法
JP2016127694A (ja) 電力変換装置及び電力変換方法
JP2022069834A (ja) 電源制御装置
WO2019017361A1 (ja) 電力変換装置
JP7823764B2 (ja) 電力変換装置、充電装置および制御方法
JP6283888B2 (ja) Ｄｃ−ｄｃコンバータ
KR101817903B1 (ko) 전기 자동차용 고강압 직류/직류 전력변환기
JP7495311B2 (ja) 電力変換装置、電力変換装置の制御方法、及び電力システム
KR102338379B1 (ko) 차량 배터리의 충전 제어 방법
CN120660271A (zh) 一体化电源装置、一体化电源装置的控制方法
WO2018235438A1 (ja) Ｄｃ－ｄｃコンバータ、これを用いた電源システム及び当該電源システムを用いた自動車
WO2020100349A1 (ja) 半導体スイッチの駆動装置、駆動方法、電力変換装置、及び車両
JP7275065B2 (ja) 電力変換装置
CN113424426B (zh) 双向谐振电路和汽车
US20250187467A1 (en) Power converter
JP7444113B2 (ja) 電力変換装置
JP2017103835A (ja) 電力変換装置、これを用いた電源システム及び自動車
JP6384422B2 (ja) 電力変換装置の制御装置

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22963512

Country of ref document: EP

Kind code of ref document: A1

WWE Wipo information: entry into national phase

Ref document number: 2024552630

Country of ref document: JP

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 22963512

Country of ref document: EP

Kind code of ref document: A1