Battery charging device and control method

Abstract

To output a different battery charging voltage without using a high breakdown voltage component.SOLUTION: A battery charging device includes: a rectifier circuit configured to rectify an AC voltage and output a rectified voltage; a boosting / lowering power factor improving circuit configured to boost or lower the rectified voltage and output a first DC voltage; an insulating converter configured to convert a voltage of the first DC voltage and output a second DC voltage to a battery; and a control unit configured to control the boosting / lowering power factor improving circuit to boost or lower the rectified voltage based on the AC voltage and the first DC voltage.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a battery charging device and a control method. [Background technology]

[0002] Patent Documents 1 to 3 describe step-up / step-down type power factor correction circuits. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2004-135372 [Patent Document 2] Japanese Patent Application Laid-Open No. 2018-68114 [Patent Document 3] International Publication No. 2018 / 109864 Summary of the Invention [Problem to be solved by the invention]

[0004] A battery charging device generally includes a boost-type power factor correction circuit and an LLC converter.

[0005] For example, the charging voltage of the traction battery of an electric motorcycle is exemplified as 48 V or 96 V. When designing to charge a traction battery with a charging voltage of 96 V, the output voltage (DC link voltage) of the power factor correction circuit is exemplified as 400 V. In other words, the transformer and other components of the LLC converter are set so that it receives a DC link voltage of 400 V from the boost-type power factor correction circuit and outputs 96 V to the traction battery.

[0006] When a charging device with an LLC converter configured as described above charges a traction battery with a charging voltage of 48 V, it is desirable that the DC link voltage be 200 V. However, if the input AC voltage is, for example, AC 265 V, a boost-type power factor correction circuit cannot step down AC 265 V to output a DC link voltage of 200 V.

[0007] On the other hand, if the target design is to charge a traction battery with a charging voltage of 48V, the transformer and other components of the LLC converter are configured so that it receives a DC link voltage of 400V from a boost-type power factor correction circuit and outputs 48V to the traction battery.

[0008] When charging a driving battery with a charging voltage of 96 V using a charging device with an LLC converter configured as described above, it is desirable that the DC link voltage be 800 V. However, when the DC link voltage is 800 V, it is essential that the boost-type power factor correction circuit and LLC converter use high-voltage (800 V or higher) components.

[0009] An object of the present disclosure is to enable output of different charging voltages without using high-voltage components. [Means for solving the problem]

[0010] A battery charging device according to one aspect of the present disclosure includes: A charging device for charging a battery, a rectifier circuit that rectifies an AC voltage and outputs a rectified voltage; a step-up / step-down voltage factor improvement circuit that steps up or steps down the rectified voltage and outputs a first DC voltage; an isolated converter that converts the first DC voltage and outputs a second DC voltage to the battery; a control unit that controls the step-up / step-down voltage factor improvement circuit so as to step up or step down the rectified voltage based on the AC voltage and the first DC voltage; Including, It is characterized by:

[0011] In the battery charging device, The control unit setting a first threshold value and a second threshold value based on the first DC voltage; When the AC voltage is equal to or greater than the first threshold value or less than the second threshold value, the step-up / step-down voltage factor improvement circuit is controlled to step down the rectified voltage; controlling the step-up / step-down voltage factor improvement circuit to step up the rectified voltage when the AC voltage is less than the first threshold value and equal to or greater than the second threshold value; It is characterized by:

[0012] In the battery charging device, The control unit controlling the boost / buck voltage factor improvement circuit to boost the rectified voltage when an absolute value of a difference between a positive peak value of the AC voltage and a first DC voltage target value that is a target value of the first DC voltage is less than a predetermined third threshold value; It is characterized by:

[0013] In the battery charging device, The control unit controlling the boost / buck voltage factor improvement circuit to boost the rectified voltage when an absolute value of a difference between a positive peak value of the AC voltage and an average value of the first DC voltage is less than a predetermined fourth threshold value; It is characterized by:

[0014] In the battery charging device, The control unit when controlling the step-up / step-down voltage factor improvement circuit to step up the rectified voltage, a predetermined correction value is added to a first DC voltage target value, which is a target value of the first DC voltage, so that the first DC voltage target value is made larger than a positive peak value of the AC voltage; It is characterized by:

[0015] In the battery charging device, a plurality of power conversion circuits each including the boost / buck voltage factor improvement circuit and the isolated converter are connected in parallel; The control unit The plurality of power conversion circuits are operated in an interleaved manner. It is characterized by:

[0016] A control method according to one aspect of the present disclosure includes: A control method for a battery charging device including a rectifier circuit that rectifies an AC voltage and outputs a rectified voltage, a step-up / step-down voltage factor improvement circuit that steps up or steps down the rectified voltage and outputs a first DC voltage, and an isolated converter that converts the first DC voltage and outputs a second DC voltage to a battery, controlling the step-up / step-down voltage factor improvement circuit so as to step up or step down the rectified voltage based on the AC voltage and the first DC voltage; It is characterized by: [Effects of the Invention]

[0017] According to the present disclosure, different charging voltages can be output without using high-voltage components. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a diagram illustrating a configuration of a charging device according to a first embodiment. [Figure 2] FIG. 2 is a diagram illustrating a configuration of the common mode filter according to the first embodiment. [Figure 3] FIG. 3 is a diagram illustrating a configuration of a rectifier circuit of the charging device according to the first embodiment. [Figure 4] FIG. 4 is a diagram illustrating a configuration of a boost / buck voltage rate improving circuit of the charging device according to the first embodiment. [Figure 5] FIG. 5 is a diagram illustrating the configuration of an insulating converter of the charging device according to the first embodiment. [Figure 6] FIG. 6 is a diagram illustrating a configuration of an output filter of the charging device according to the first embodiment. [Figure 7] FIG. 7 is a diagram illustrating a configuration of a control unit of the charging device according to the first embodiment. [Figure 8]FIG. 8 is a diagram illustrating an example of a waveform of the charging device according to the first embodiment. [Figure 9] FIG. 9 is a diagram illustrating an example of a waveform of the charging device according to the first embodiment. [Figure 10] FIG. 10 is a diagram illustrating the configuration of a charging device according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Note that the present disclosure is not limited to these embodiments, and in the following embodiments, the same components are designated by the same reference numerals, and redundant description will be omitted.

[0020] First Embodiment (Overall composition) FIG. 1 is a diagram illustrating a configuration of a charging device according to a first embodiment.

[0021] The charging device 1 receives an AC voltage that is output from an AC power source 2 and passes through a fuse 3 and a common mode filter 4, and outputs a DC voltage to a battery 5 to charge the battery 5.

[0022] One end of the fuse 3 is electrically connected to one end of the AC power supply 2, and the other end is electrically connected to a terminal 4a of the common mode filter 4. The fuse 3 is provided to protect the AC power supply 2. The fuse 3 is, for example, a current fuse that melts due to self-heating when the current passing through it exceeds the rated current.

[0023] The common mode filter 4 suppresses common mode noise. A terminal 4a of the common mode filter 4 is electrically connected to the other end of the fuse 3. A terminal 4b of the common mode filter 4 is electrically connected to the other end of the AC power supply 2.

[0024] The charging device 1 includes a rectifier circuit 11, a boost / buck voltage rate improvement circuit 12, an insulating converter 13, an output filter 14, a control unit 15, a voltage detector 21, a voltage detector 22, a current detector 23, a voltage detector 24, a voltage detector 25, and a current detector 26.

[0025] The rectifier circuit 11 rectifies the AC input voltage Vin after passing through the common mode filter 4 and outputs a rectified voltage V1 to the boost / buck voltage factor improvement circuit 12.

[0026] The rectified voltage V1 corresponds to an example of the "rectified voltage" of the present disclosure.

[0027] Terminal 11a of rectifier circuit 11 is electrically connected to terminal 4c of common mode filter 4. Terminal 11b of rectifier circuit 11 is electrically connected to terminal 4d of common mode filter 4. Terminal 11c of rectifier circuit 11 is electrically connected to terminal 12a of boost / buck pressure ratio improvement circuit 12. Terminal 11d of rectifier circuit 11 is electrically connected to terminal 12b of boost / buck pressure ratio improvement circuit 12.

[0028] The boost / buck voltage factor correction circuit 12 corrects the power factor of the power output from the rectifier circuit 11. The boost / buck voltage factor correction circuit 12 boosts or bucks the rectified voltage V1 and outputs a DC link voltage Vlink to the isolated converter 13.

[0029] The DC link voltage Vlink corresponds to an example of a "first DC voltage" in the present disclosure.

[0030] A terminal 12c of the boost / buck pressure ratio improvement circuit 12 is electrically connected to a terminal 13a of the insulating converter 13. A terminal 12d of the boost / buck pressure ratio improvement circuit 12 is electrically connected to a terminal 13b of the insulating converter 13.

[0031] The insulating converter 13 steps down the DC link voltage Vlink output from the boost / buck voltage factor improvement circuit 12 and outputs a voltage V2 to the output filter 14.

[0032] The voltage V2 corresponds to an example of the "second DC voltage" of the present disclosure.

[0033] A terminal 13c of the insulating converter 13 is electrically connected to a terminal 14a of the output filter 14. A terminal 13d of the insulating converter 13 is electrically connected to a terminal 14b of the output filter 14.

[0034] The output filter 14 suppresses noise in the voltage V2 output from the insulating converter 13 and outputs the output voltage Vout to the battery 5.

[0035] The output voltage Vout corresponds to an example of the "output voltage" in the present disclosure.

[0036] Terminal 14c of output filter 14 is electrically connected to the high potential side terminal of battery 5. Terminal 14d of output filter 14 is electrically connected to the low potential side terminal of battery 5.

[0037] The voltage detector 21 detects the first-phase AC input voltage Vin_U between the terminal 4c of the common mode filter 4 and the terminal 11d of the rectifier circuit 11, and outputs a detection signal representing the first-phase AC input voltage Vin_U to the control unit 15.

[0038] The voltage detector 22 detects the second-phase AC input voltage Vin_V between the terminal 4d of the common mode filter 4 and the terminal 11d of the rectifier circuit 11, and outputs a detection signal representing the second-phase AC input voltage Vin_V to the control unit 15.

[0039] The difference between the first-phase AC input voltage Vin_U and the second-phase AC input voltage Vin_V is the AC input voltage Vin.

[0040] The current detector 23 detects the input current Iin input from the common mode filter 4 to the rectifier circuit 11, and outputs a detection signal representing the input current Iin to the control unit 15.

[0041] The voltage detector 24 detects the DC link voltage Vlink output between the terminals 12c and 12d of the boost / buck voltage factor improvement circuit 12, and outputs a detection signal representing the DC link voltage Vlink to the control unit 15.

[0042] The voltage detector 25 detects the output voltage Vout output from the output filter 14 to the battery 5, and outputs a detection signal representing the output voltage Vout to the control unit 15.

[0043] The current detector 26 detects the output current Iout output from the output filter 14 to the battery 5, and outputs a detection signal representing the output current Iout to the control unit 15.

[0044] [Common mode filter configuration] FIG. 2 is a diagram illustrating a configuration of the common mode filter according to the first embodiment.

[0045] The common mode filter 4 includes a capacitor 101 , a transformer 102 , and a capacitor 103 .

[0046] One end of the capacitor 101 is electrically connected to the terminal 4a, and the other end of the capacitor 101 is electrically connected to the terminal 4b.

[0047] The transformer 102 includes a first winding 102a, a second winding 102b, and a core 102c. The first winding 102a and the second winding 102b are wound around the core 102c.

[0048] One end of the first winding 102a is electrically connected to the terminal 4a, and the other end of the first winding 102a is electrically connected to the terminal 4c.

[0049] One end of the second winding 102b is electrically connected to the terminal 4b, and the other end of the second winding 102b is electrically connected to the terminal 4d.

[0050] One end of the capacitor 103 is electrically connected to the terminal 4c, and the other end of the capacitor 103 is electrically connected to the terminal 4d.

[0051] The common mode filter 4 outputs the AC input voltage Vin to the rectifier circuit 11 from between the terminal 4c and the terminal 4d.

[0052] [Rectifier circuit configuration] FIG. 3 is a diagram illustrating a configuration of a rectifier circuit of the charging device according to the first embodiment.

[0053] The rectifier circuit 11 is a bridge diode and includes diodes 111 to 114.

[0054] The anode of the diode 111 is electrically connected to the terminal 11a, and the cathode of the diode 111 is electrically connected to the terminal 11c.

[0055] The anode of the diode 112 is electrically connected to the terminal 11d, and the cathode of the diode 112 is electrically connected to the terminal 11a.

[0056] The anode of the diode 113 is electrically connected to the terminal 11b, and the cathode of the diode 113 is electrically connected to the terminal 11c.

[0057] The anode of the diode 114 is electrically connected to the terminal 11d, and the cathode of the diode 114 is electrically connected to the terminal 11b.

[0058] The rectifier circuit 11 full-wave rectifies an AC input voltage Vin input between terminals 11a and 11b, and outputs a rectified voltage V1 to the boost / buck ratio improvement circuit 12 from between terminals 11c and 11d.

[0059] [Configuration and operation of the boost / decrease pressure ratio improvement circuit] FIG. 4 is a diagram illustrating a configuration of a boost / buck voltage rate improving circuit of the charging device according to the first embodiment.

[0060] The boost / buck voltage ratio improvement circuit 12 includes a switching element 121 , a diode 122 , an inductor 123 , a diode 124 , a switching element 125 , and a capacitor 126 .

[0061] In the embodiment, each switching element is a transistor, but the present disclosure is not limited to this. Also, each transistor is a MOSFET, but the present disclosure is not limited to this. Each transistor may be a silicon power device, a GaN power device, a SiC power device (e.g., an IGBT (Insulated Gate Bipolar Transistor)), or the like. Also, diode 122 and diode 124 may be replaced with a switching element (e.g., a MOSFET, a silicon power device, a GaN power device, a SiC power device (e.g., an IGBT)).

[0062] Each transistor has a parasitic diode (body diode) that can actively conduct current, or has a diode connected in anti-parallel: the pn junction between the back gate and the source and drain of the MOSFET.

[0063] The drain of the switching element 121 is electrically connected to the terminal 12a. The source of the switching element 121 is electrically connected to the node N1. The control unit 15 inputs a switching control signal S1-1 to the gate of the switching element 121.

[0064] The anode of the diode 122 is electrically connected to the terminal 12b and the terminal 12d, and the cathode of the diode 122 is electrically connected to the node N1.

[0065] One end of the inductor 123 is electrically connected to the node N1, and the other end of the inductor 123 is electrically connected to the node N2.

[0066] The anode of the diode 124 is electrically connected to the node N2, and the cathode of the diode 124 is electrically connected to the terminal 12c.

[0067] The drain of the switching element 125 is electrically connected to the node N2. The source of the switching element 125 is electrically connected to the terminal 12b and the terminal 12d. The switching element 125 receives a switching control signal S1-2 as an input from the control unit to its gate.

[0068] One end of the capacitor 126 is electrically connected to the terminal 12c, and the other end of the capacitor 126 is electrically connected to the terminal 12d.

[0069] The voltage across capacitor 126 is the DC link voltage Vlink.

[0070] The boosting operation of the boost / decrease voltage ratio improvement circuit 12 will be described.

[0071] When the boost / buck ratio improvement circuit 12 performs boosting, the switching element 121 is maintained in the on state, and the switching element 125 is controlled to be turned on and off.

[0072] When switching element 125 is in the on state, current flows through the path of terminal 12a → switching element 121 → inductor 123 → switching element 125 → terminal 12b, and electromagnetic energy is stored in inductor 123. At this time, the voltage across inductor 123 is the rectified voltage V1 between terminals 12a and 12b.

[0073] When the switching element 125 is in the off state, a current flows through the path of the terminal 12a, the switching element 121, the inductor 123, the diode 124, the capacitor 126, and the terminal 12b. At this time, the sum of the rectified voltage V1 between the terminals 12a and 12b and the voltage of the inductor 123 is applied to the capacitor 126.

[0074] This allows the boost / buck voltage ratio improvement circuit 12 to achieve a boost operation.

[0075] The step-down operation of the step-up / step-down voltage ratio improvement circuit 12 will be described.

[0076] When the boost / buck ratio improvement circuit 12 performs voltage reduction, the switching element 125 is maintained in the OFF state, and the switching element 121 is ON / OFF controlled.

[0077] When the switching element 121 is in the on state, a current flows through the path of terminal 12a → switching element 121 → inductor 123 → diode 124 → capacitor 126 → terminal 12b, and electromagnetic energy is stored in the inductor 123. At this time, the voltage across the inductor 123 is the difference between the rectified voltage V1 between terminals 12a and 12b and the DC link voltage Vlink of the capacitor 126.

[0078] When the switching element 121 is in an OFF state, a current flows through the other end of the inductor 123, the diode 124, the capacitor 126, the diode 122, and the one end of the inductor 123. At this time, the voltage of the inductor 123 is applied to the capacitor 126.

[0079] This allows the boost / buck voltage ratio improvement circuit 12 to achieve a voltage step-down operation.

[0080] [Configuration and operation of isolated converter] FIG. 5 is a diagram illustrating the configuration of an insulating converter of the charging device according to the first embodiment.

[0081] The isolated converter 13 includes a bridge circuit 130, a transformer 133, and a rectifier circuit 134. Note that the isolated converter 13 shown in Fig. 5 is an example, and the present disclosure is not limited thereto. The isolated converter 13 can have various circuit configurations.

[0082] The bridge circuit 130 is a single-phase full-bridge circuit including an arm 131 and an arm 132 .

[0083] The arm 131 includes a switching element 131a and a switching element 131b.

[0084] The drain of the switching element 131a is electrically connected to the terminal 13a. The source of the switching element 131a is electrically connected to a node N11. A switching control signal S2-1 is input from the control unit 15 to the gate of the switching element 131a.

[0085] The drain of the switching element 131b is electrically connected to the node N11. The source of the switching element 131b is electrically connected to the terminal 13b. The control unit 15 inputs a switching control signal S2-2 to the gate of the switching element 131b.

[0086] The arm 132 includes a switching element 132a and a switching element 132b.

[0087] The drain of the switching element 132a is electrically connected to the terminal 13a. The source of the switching element 132a is electrically connected to the node N12. The control unit 15 inputs a switching control signal S2-3 to the gate of the switching element 132a.

[0088] The drain of the switching element 132b is electrically connected to the node N12. The source of the switching element 132b is electrically connected to the terminal 13b. The control unit 15 inputs a switching control signal S2-4 to the gate of the switching element 132b.

[0089] The transformer 133 includes a first winding 133a, a second winding 133b, and a core 133c. The first winding 133a and the second winding 133b are wound around the core 133c.

[0090] One end of the first winding 133a is electrically connected to a node N11, and the other end of the first winding 133a is electrically connected to a node N12.

[0091] One end of the second winding 133b is electrically connected to a node N13, and the other end of the second winding 133b is electrically connected to a node N14.

[0092] The rectifier circuit 134 is a bridge diode and includes diodes 134a to 134d.

[0093] The anode of the diode 134a is electrically connected to the node N13, and the cathode of the diode 134a is electrically connected to the terminal 13c.

[0094] The anode of the diode 134b is electrically connected to the terminal 13d, and the cathode of the diode 134b is electrically connected to the node N13.

[0095] The anode of the diode 134c is electrically connected to the node N14, and the cathode of the diode 134c is electrically connected to the terminal 13c.

[0096] The anode of the diode 134d is electrically connected to the terminal 13d, and the cathode of the diode 134d is electrically connected to the node N14.

[0097] The operation of the insulating converter 13 will now be described.

[0098] The bridge circuit 130 outputs the DC link voltage Vlink, a voltage −Vlink that is in phase opposite to the DC link voltage Vlink, or 0 V between the node N11 and the node N12.

[0099] For example, when the switching elements 131a and 132b are controlled to be in the on state and the switching elements 131b and 132a are controlled to be in the off state, the bridge circuit 130 outputs the DC link voltage Vlink between the node N11 and the node N12.

[0100] Furthermore, for example, when the switching elements 131a and 132b are controlled to be in the off state and the switching elements 131b and 132a are controlled to be in the on state, the bridge circuit 130 outputs the voltage −Vlink between the node N11 and the node N12.

[0101] Furthermore, for example, when the switching elements 131a and 132a are controlled to be in the ON state and the switching elements 131b and 132b are controlled to be in the OFF state, the bridge circuit 130 outputs 0 V between the node N11 and the node N12.

[0102] The voltage between the node N11 and the node N12 is applied to the first winding 133a, and a voltage is induced in the second winding 133b.

[0103] The rectifier circuit 134 full-wave rectifies the AC voltage input between the node N13 and the node N14, and outputs a voltage V2 to the output filter 14 from between the terminal 13c and the terminal 13d.

[0104] For example, the transformer 133 and other components are configured so that the isolated converter 13 efficiently outputs 48 V when the DC link voltage Vlink is 200 V, and efficiently outputs 96 V when the DC link voltage Vlink is 400 V. In other words, the ratio n of input voltage to output power that is efficient for the isolated converter 13 is set to n = 200 / 48 = 400 / 96 = 4.166.

[0105] [Output filter configuration] FIG. 6 is a diagram illustrating a configuration of an output filter of the charging device according to the first embodiment.

[0106] The output filter 14 includes an inductor 141 , a capacitor 142 , and a diode 143 .

[0107] One end of the inductor 141 is electrically connected to the terminal 14a, and the other end of the inductor 141 is electrically connected to the node N21.

[0108] One end of the capacitor 142 is electrically connected to the node N21, and the other end of the capacitor 142 is electrically connected to the terminal 14b and the terminal 14d.

[0109] The anode of the diode 143 is electrically connected to the node N21, and the cathode of the diode 143 is electrically connected to the terminal 14c.

[0110] The output filter 14 suppresses noise in the voltage V2 input between the terminals 14a and 14b, and outputs the output voltage Vout to the battery 5 from between the terminals 11c and 11d.

[0111] [Configuration and operation of the control unit] FIG. 7 is a diagram illustrating a configuration of a control unit of the charging device according to the first embodiment.

[0112] The control unit 15 includes an AD conversion unit 15a, a communication unit 15b, a subtractor 15c, an input voltage instantaneous value output unit 15d, an input current instantaneous value output unit 15e, a DC link voltage average value output unit 15f, a DC link voltage instantaneous value output unit 15g, an output voltage average value output unit 15h, an output voltage instantaneous value output unit 15i, an output current instantaneous value output unit 15j, a boost / buck pressure factor improvement circuit control unit 15k, an active current command value calculation unit 15l, a subtractor 15m, a target DC link voltage calculation unit 15n, an isolation converter control unit 15o, a duty calculation unit 15p, a switching control signal output unit 15q, a phase control amount calculation unit 15r, and a switching control signal output unit 15s.

[0113] The AD conversion unit 15a converts the detection signal output from the voltage detector 21 and indicating the first-phase AC input voltage Vin_U into a digital value and outputs the digital value to the subtractor 15c.

[0114] The AD conversion unit 15a converts the detection signal, which is output from the voltage detector 22 and indicates the second-phase AC input voltage Vin_V, into a digital value and outputs the digital value to the subtractor 15c.

[0115] The AD conversion unit 15a converts the detection signal representing the input current Iin output from the current detector 23 into a digital value and outputs it to the input current instantaneous value output unit 15e.

[0116] The AD conversion unit 15a converts the detection signal representing the DC link voltage Vlink output from the voltage detector 24 into a digital value and outputs it to a DC link voltage average value output unit 15f and a DC link voltage instantaneous value output unit 15g.

[0117] The AD conversion unit 15a converts the detection signal representing the output voltage Vout output from the voltage detector 25 into a digital value and outputs it to the output voltage average value output unit 15h and the output voltage instantaneous value output unit 15i.

[0118] The AD conversion unit 15a converts the detection signal, which is output from the current detector 26 and indicates the output current Iout, into a digital value and outputs the digital value to the output current instantaneous value output unit 15j.

[0119] The communication unit 15b receives the charging current instruction value S11 from an external device and outputs it to the insulating converter control unit 15o.

[0120] The communication unit 15b receives the charge end voltage instruction value S12 from the external device and outputs it to the insulating converter control unit 15o.

[0121] The subtractor 15c subtracts the digital value of the second-phase AC input voltage Vin_V from the digital value of the first-phase AC input voltage Vin_U to calculate an input voltage instantaneous value S31, and outputs the input voltage instantaneous value S31 to the input voltage instantaneous value output unit 15d.

[0122] The input voltage instantaneous value output unit 15d outputs the input voltage instantaneous value S32 to the boost / buck pressure ratio improvement circuit control unit 15k and the target DC link voltage calculation unit 15n.

[0123] The input current instantaneous value output unit 15e outputs the input current instantaneous value S33 to the boost / decrease pressure ratio improvement circuit control unit 15k.

[0124] The DC link voltage average value output unit 15f calculates a DC link voltage average value S34 by averaging the digital values ​​of the DC link voltage Vlink and outputs the DC link voltage average value S34 to the subtractor 15m. The DC link voltage average value output unit 15f calculates a moving average of the DC link voltage Vlink, for example, but the present disclosure is not limited to this.

[0125] The DC link voltage instantaneous value output unit 15g outputs the DC link voltage instantaneous value S35 to the boost / buck pressure factor improvement circuit control unit 15k, the insulating converter control unit 15o, and the duty calculation unit 15p.

[0126] The output voltage average value output unit 15h calculates an output voltage average value S36 by averaging the digital values ​​of the output voltage Vout, and outputs the output voltage average value S36 to the target DC link voltage calculation unit 15n. The output voltage average value output unit 15h calculates a moving average of the output voltage Vout, for example, but the present disclosure is not limited to this.

[0127] The output voltage instantaneous value output unit 15i outputs the output voltage instantaneous value S37 to the insulating converter control unit 15o.

[0128] The output current instantaneous value output unit 15j outputs the output current instantaneous value S38 to the insulating converter control unit 15o.

[0129] The target DC link voltage calculation unit 15n calculates a target DC link voltage S39 based on the output voltage average value S36.

[0130] The target DC link voltage S39 corresponds to an example of a "first DC voltage target value" in the present disclosure.

[0131] As explained above, the ratio n of input voltage to output power at which the isolated converter 13 is efficient is set to n=4.166.

[0132] Therefore, the target DC link voltage calculation unit 15n calculates the target DC link voltage S39 using the following equation (1).

[0133] However, in the case where an event such as that described later may occur, the target DC link voltage calculation unit 15n calculates the target DC link voltage S39 using equation (2) described later.

[0134] (Target DC link voltage S39) = (average output voltage S36) × n (1)

[0135] The boost / buck pressure ratio improving circuit control unit 15k controls the boost / buck pressure ratio improving circuit 12 to boost or buck the voltage based on the input voltage instantaneous value S32 and the DC link voltage instantaneous value S35.

[0136] FIG. 8 is a diagram illustrating an example of a waveform of the charging device according to the first embodiment.

[0137] In FIG. 8, a line 201 indicates the instantaneous value S32 of the input voltage.

[0138] A line 202 indicates the positive first threshold value Th1. The boost / buck pressure ratio improving circuit control unit 15k sets the DC link voltage instantaneous value S35 as the first threshold value Th1.

[0139] The first threshold value Th1 corresponds to an example of the "first threshold value" in the present disclosure.

[0140] A line 203 indicates the negative second threshold value Th2. The boost / buck pressure ratio improving circuit control unit 15k sets the sign-inverted value of the DC link voltage instantaneous value S35 as the second threshold value Th2.

[0141] The second threshold value Th2 corresponds to an example of the "second threshold value" in the present disclosure.

[0142] A line 204 indicates whether the boost / decrease voltage ratio improvement circuit 12 performs boost (high level) or buck (low level).

[0143] As shown by line 201, the input voltage instantaneous value S32 is in a positive phase (positive polarity) from timing t0 to timing t3, and in a negative phase (negative polarity) from timing t3 to timing t6.

[0144] Between timing t0 and timing t1, the first threshold value Th1 is greater than the input voltage instantaneous value S32, so the boost / decrease pressure rate improvement circuit control unit 15k controls the boost / decrease pressure rate improvement circuit 12 to boost the voltage. That is, between timing t0 and timing t1, the line 204 is at a high level.

[0145] Between timing t1 and timing t2, the first threshold value Th1<the input voltage instantaneous value S32, so the boost / decrease pressure rate improvement circuit control unit 15k controls the boost / decrease pressure rate improvement circuit 12 to step down the voltage. That is, between timing t1 and timing t2, the line 204 is at a low level.

[0146] Between timing t2 and timing t3, the first threshold value Th1 is greater than the input voltage instantaneous value S32, so the boost / decrease pressure rate improvement circuit control unit 15k controls the boost / decrease pressure rate improvement circuit 12 to boost the voltage. That is, between timing t2 and timing t3, the line 204 is at a high level.

[0147] Between timing t3 and timing t4, the second threshold value Th2<the input voltage instantaneous value S32, so the boost / decrease pressure rate improvement circuit control unit 15k controls the boost / decrease pressure rate improvement circuit 12 to boost the voltage. That is, between timing t3 and timing t4, the line 204 is at a high level.

[0148] Between timing t4 and timing t5, the second threshold value Th2 is greater than the input voltage instantaneous value S32, so the boost / decrease pressure rate improvement circuit control unit 15k controls the boost / decrease pressure rate improvement circuit 12 to step down the voltage. That is, between timing t4 and timing t5, the line 204 is at a low level.

[0149] During the period from timing t5 to timing t6, since the second threshold Th2 < the instantaneous input voltage value S32, the buck-boost power factor improvement circuit control unit 15k controls the buck-boost power factor improvement circuit 12 to perform boosting. That is, during the period from timing t5 to timing t6, line 204 is at a high level.

[0150] In this way, when the instantaneous input voltage value S32 is greater than or equal to the first threshold Th1 or less than the second threshold Th2, the buck-boost power factor improvement circuit control unit 15k controls the buck-boost power factor improvement circuit to step down the rectified voltage V1. Also, when the instantaneous input voltage value S32 is less than the first threshold Th1 and greater than or equal to the second threshold Th2, the buck-boost power factor improvement circuit control unit 15k controls the buck-boost power factor improvement circuit to step up the rectified voltage V1.

[0151] However, when the following events may occur, the target DC link voltage calculation unit 15n calculates the target DC link voltage S39 using the formula (2) described later.

[0152] FIG. 9 is a diagram showing an example of waveforms of the charging device according to the first embodiment.

[0153] In FIG. 9, line 211 indicates the rectified voltage V1 output from the rectifier circuit 11. The rectified voltage V1 can be considered to be equal to the absolute value of the instantaneous input voltage value S32.

[0154] Line 212 indicates the output current of the rectifier circuit 11. Line 213 indicates the instantaneous DC link voltage value S35.

[0155] As shown in FIG. 9, consider the case where the positive peak value of the rectified voltage V1 and the instantaneous DC link voltage value S35 are close.

[0156] 昇降圧力率改善回路制御部15kは、タイミングt (This part seems to be incomplete in the original Chinese. It might be better to correct the original text for a more accurate translation. For now, I'll keep it as is.) 10 までの期間では、整流電圧V1<DCリンク電圧瞬時値S35であるので、昇降圧力率改善回路12に昇圧を行うように制御する。 During the period until timing t, since the rectified voltage V1 < the instantaneous DC link voltage value S35, the buck-boost power factor improvement circuit control unit 15k controls the buck-boost power factor improvement circuit 12 to perform boosting.

[0157] 昇降圧力率改善回路制御部15kは、タイミングt (This part seems to be incomplete in the original Chinese. It might be better to correct the original text for a more accurate translation. For now, I'll keep it as is.)10 From timing t 11 During the period until, since the rectified voltage V1 > the instantaneous value S35 of the DC link voltage, the boost - buck power factor improvement circuit 12 is controlled to perform bucking.

[0158] The boost - buck power factor improvement circuit control unit 15k, at timing t 11 After that period, since the rectified voltage V1 < the instantaneous value S35 of the DC link voltage, the boost - buck power factor improvement circuit 12 is controlled to perform boosting.

[0159] Thus, the boost - buck power factor improvement circuit control unit 15k performs switching to cause the boost - buck power factor improvement circuit 12 to perform boosting or bucking based on the instantaneous value S32 of the input voltage (the absolute value is equivalent to the rectified voltage V1) and the instantaneous value S35 of the DC link voltage.

[0160] [[ID=ID=17]]However, when detecting the instantaneous value S32 of the input voltage and the average value S36 of the output voltage, errors may occur due to detection delay in the AD conversion unit 15a and detection accuracy. Due to this error, events such as bucking at the timing when boosting should be performed or boosting at the timing when bucking should be performed may occur. In such a case, as shown by the line 214 in FIG. 8, it will cause disturbance of the input current Iin.

[0161] Therefore, when the absolute value of the difference between the positive peak value of the instantaneous value S32 of the input voltage and the target DC link voltage S39 (= (average value S36 of the output voltage) × n) is less than a predetermined third threshold Th3, the target DC link voltage calculation unit 15n adds a predetermined correction value α to the target DC link voltage S39 to make the target DC link voltage S39 larger than the positive peak value of the instantaneous value S32 of the input voltage.

[0162] The third threshold Th3 corresponds to an example of the "third threshold" of the present disclosure. The correction value α corresponds to an example of the "correction value" of the present disclosure.

[0163] That is, when the absolute value of the difference between the positive peak value of the input voltage instantaneous value S32 and the target DC link voltage S39 is less than the third threshold value Th3, the target DC link voltage calculator 15n calculates the target DC link voltage S39 using the following equation (2).

[0164] (Target DC link voltage S39) = (Average output voltage S36) × n + α (2)

[0165] In FIG. 8, a line 215 indicates the target DC link voltage S39 calculated by equation (2).

[0166] In this way, the target DC link voltage calculation unit 15n sets the target DC link voltage S39 to be greater than the positive peak value of the input voltage instantaneous value S32, whereby the boost / buck pressure factor improvement circuit control unit 15k controls the boost / buck pressure factor improvement circuit 12 to boost the rectified voltage V1.

[0167] As a result, the boost / buck voltage factor improvement circuit control unit 15k controls the boost / buck voltage factor improvement circuit 12 so as to boost the rectified voltage V1 after timing t1, thereby making it possible to suppress disturbances in the input current Iin.

[0168] It is preferable that the value of the correction value α is set to a value that takes into account errors due to detection delays and detection accuracy in the AD conversion unit 15a and prevents events such as voltage being lowered when it should be increased, or voltage being increased when it should be decreased.

[0169] Furthermore, the purpose of the boost / buck voltage factor improvement circuit 12 is to output a DC link voltage Vlink that corresponds to the output voltage Vout, so it is preferable that the correction value α is as small as possible.

[0170] To sum up the above, it is preferable that the value of the correction value α is a value that prevents an event such as a voltage drop at a timing when a voltage increase should be made, or a voltage increase at a timing when a voltage decrease should be made, and that the value is as small as possible.

[0171] In the embodiment, the target DC link voltage calculator 15n adds the correction value α to the target DC link voltage S39 when the absolute value of the difference between the positive peak value of the input voltage instantaneous value S32 and the DC link voltage instantaneous value S35 is less than a predetermined third threshold value Th3. However, the present disclosure is not limited to this. The target DC link voltage calculator 15n may also add the correction value α to the target DC link voltage S39 when the absolute value of the difference between the positive peak value of the input voltage instantaneous value S32 and the DC link voltage average value S34 is less than a predetermined fourth threshold value Th4.

[0172] The fourth threshold value Th4 corresponds to an example of the "fourth threshold value" of the present disclosure.

[0173] Referring again to FIG. 7, the subtractor 15m subtracts the DC link voltage average value S34 from the target DC link voltage S39 to calculate a DC link voltage deviation S40, and outputs the DC link voltage deviation S40 to the active current command value calculation unit 15l.

[0174] The active current command value calculation unit 15l calculates an active current command value S41 based on the DC link voltage deviation S40, and outputs the active current command value S41 to the boost / buck pressure ratio improvement circuit control unit 15k.

[0175] As described above, the boost / buck pressure ratio improvement circuit control unit 15k determines whether to cause the boost / buck pressure ratio improvement circuit 12 to boost or buck the voltage based on the DC link voltage instantaneous value S35 and the input voltage instantaneous value S32. The boost / buck pressure ratio improvement circuit control unit 15k also sets the target DC link voltage S39 as the target output voltage of the boost / buck pressure ratio improvement circuit 12.

[0176] Further, the boost / decrease pressure ratio improving circuit control section 15k determines the target output current of the boost / decrease pressure ratio improving circuit 12 based on the input current instantaneous value S33 and the active current command value S41.

[0177] The boost / buck pressure rate improvement circuit control unit 15k outputs a signal S42 to the duty calculation unit 15p, which includes information on whether the boost / buck pressure rate improvement circuit 12 should perform boost or buck, the target output voltage of the boost / buck pressure rate improvement circuit 12, and the target output current of the boost / buck pressure rate improvement circuit 12.

[0178] The duty calculation unit 15p calculates a duty S43 of the switching control signal S1 based on the DC link voltage instantaneous value S35 and the signal S42, and outputs the duty S43 to the switching control signal output unit 15q.

[0179] The switching control signal output unit 15q outputs the switching control signal S1 to the boost / buck voltage ratio improvement circuit 12 based on the duty S43.

[0180] The insulating converter control unit 15o determines a target output current of the insulating converter 13 based on the charging current command value S11 and the output current instantaneous value S38.

[0181] Furthermore, the insulating converter control unit 15o determines the target output voltage of the insulating converter 13 based on the charge end voltage command value S12, the DC link voltage instantaneous value S35, and the output voltage instantaneous value S37.

[0182] The insulating converter 13 outputs a signal S44 including information on the target output current and the target output voltage of the insulating converter 13 to the phase control amount calculation unit 15r.

[0183] The phase control amount calculation unit 15r calculates a phase control amount S45 of the isolated converter 13 based on the target output current and target output voltage of the isolated converter 13, and outputs the phase control amount S45 to the switching control signal output unit 15s.

[0184] The switching control signal output unit 15s outputs the switching control signal S2 to the insulating converter 13 based on the phase control amount S45.

[0185] (effect) In this manner, in the charging device 1, the step-up / step-down voltage factor improvement circuit 12 steps up or steps down the rectified voltage V1 and outputs the DC link voltage Vlink to the insulating converter 13.

[0186] Therefore, for example, when the AC input voltage Vin is AC 265V and the charging voltage of the battery 5 is 96V, the boost / buck voltage factor improvement circuit 12 can boost the rectified voltage V1 and output a DC link voltage Vlink of 400V.

[0187] Furthermore, for example, when the AC input voltage Vin is AC 265V and the charging voltage of the battery 5 is 48V, the boost / buck voltage factor improvement circuit 12 can step down the rectified voltage V1 and output a DC link voltage Vlink of 200V.

[0188] In this way, the charging device 1 can output different battery charging voltages without using high-voltage components.

[0189] <Second embodiment> (composition) FIG. 10 is a diagram illustrating the configuration of a charging device according to the second embodiment.

[0190] Compared to the charging device 1 (see FIG. 1), the charging device 1A includes a power conversion circuit 51 and a power conversion circuit 52 instead of the boost / buck voltage ratio improvement circuit 12 and the insulating converter 13.

[0191] The power conversion circuit 51 includes a boost / buck voltage ratio improvement circuit 12-1 and an insulating converter 13-1.

[0192] The circuit configuration of the boost / drop pressure ratio improving circuit 12-1 is the same as the circuit configuration of the boost / drop pressure ratio improving circuit 12 (see FIG. 4), and therefore a description thereof will be omitted.

[0193] The circuit configuration of the insulating converter 13-1 is similar to the circuit configuration of the insulating converter 13 (see FIG. 5), and therefore a description thereof will be omitted.

[0194] The power conversion circuit 52 includes a boost / buck voltage ratio improvement circuit 12-2 and an insulating converter 13-2.

[0195] The circuit configuration of the boost / drop pressure ratio improving circuit 12-2 is the same as the circuit configuration of the boost / drop pressure ratio improving circuit 12 (see FIG. 4), and therefore a description thereof will be omitted.

[0196] The circuit configuration of the insulating converter 13-2 is similar to the circuit configuration of the insulating converter 13 (see FIG. 5), and therefore a description thereof will be omitted.

[0197] A terminal 12-1a of the boost / decrease pressure ratio improvement circuit 12-1 is electrically connected to a terminal 11c of the rectifier circuit 11 and a terminal 12-2a of the boost / decrease pressure ratio improvement circuit 12-2.

[0198] A terminal 12-1b of the boost / drop pressure ratio improvement circuit 12-1 is electrically connected to a terminal 11d of the rectifier circuit 11 and a terminal 12-2b of the boost / drop pressure ratio improvement circuit 12-2.

[0199] A terminal 12-1c of the boost / buck pressure ratio improvement circuit 12-1 is electrically connected to a terminal 13-1a of the isolated converter 13-1, a terminal 12-2c of the boost / buck pressure ratio improvement circuit 12-2, and a terminal 13-2a of the isolated converter 13-2.

[0200] A terminal 12-1d of the boost / buck pressure ratio improvement circuit 12-1 is electrically connected to a terminal 13-1b of the isolated converter 13-1, a terminal 12-2d of the boost / buck pressure ratio improvement circuit 12-2, and a terminal 13-2b of the isolated converter 13-2.

[0201] A terminal 13-1c of the isolated converter 13-1 is electrically connected to a terminal 14a of the output filter 14 and a terminal 13-2c of the isolated converter 13-2.

[0202] A terminal 13-1d of the isolated converter 13-1 is electrically connected to a terminal 14b of the output filter 14 and a terminal 13-2d of the isolated converter 13-2.

[0203] In this way, the boost / decrease pressure factor improvement circuit 12-1 and the boost / decrease pressure factor improvement circuit 12-2 are connected in parallel. Also, the insulating converter 13-1 and the insulating converter 13-2 are connected in parallel. That is, the power conversion circuit 51 and the power conversion circuit 52 are connected in parallel.

[0204] It is preferable that the control unit 15 causes the power conversion circuit 51 and the power conversion circuit 52 to perform interleaved operations.

[0205] (effect) If a high-output charging device and a low-output charging device are designed separately, the development man-hours will be long.

[0206] On the other hand, the charging device 1A has a power conversion circuit 51 including a step-up / step-down voltage rate improvement circuit 12-1 and an insulating converter 13-1 connected in parallel with a power conversion circuit 52 including a step-up / step-down voltage rate improvement circuit 12-2 and an insulating converter 13-2. As a result, the charging device 1A has a larger output than the charging device 1.

[0207] That is, a high-output charging device 1A can be realized by simply designing one type of boost / buck voltage factor improvement circuit 12 and one type of insulating converter 13. In other words, a high-output charging device 1A can be realized by simply designing a low-output charging device 1.

[0208] As a result, the number of development steps required for the charging device 1A can be reduced compared to when a large-output charging device and a small-output charging device are designed separately.

[0209] Furthermore, it is preferable that the control unit 15 causes the power conversion circuit 51 and the power conversion circuit 52 to perform interleaved operations.

[0210] As a result, the frequency of the voltage applied to inductor 141 (see FIG. 6) in output filter 14 is doubled.

[0211] Since the frequency of the voltage applied to inductor 141 is doubled, it is no longer necessary to increase the inductance value, and the inductance value can be suppressed.

[0212] This allows the charging device 1A to prevent the inductor 141 from becoming large.

[0213] In addition, the control unit 15 does not detect (use) the current of the inductor 123 (see Figure 4) in the boost / buck pressure factor improvement circuit 12-1 and the boost / buck pressure factor improvement circuit 12-2, but detects (uses) the input current Iin input from the common mode filter 4 to the rectifier circuit 11.

[0214] If the current of the inductor 123 in the boost / drop pressure factor improvement circuit 12-1 and the boost / drop pressure factor improvement circuit 12-2 is to be detected, two current detectors are required.

[0215] On the other hand, the charging device 1A can perform control using only one current detector 23 that detects the input current Iin input from the common mode filter 4 to the rectifier circuit 11, as shown in FIG.

[0216] This allows the charging device 1A to reduce the number of current detectors.

[0217] Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the contents of these embodiments. Furthermore, the above-described components include those that can be easily imagined by a person skilled in the art, those that are substantially the same, and those that are within the so-called equivalent range. Furthermore, the above-described components can be combined as appropriate. Furthermore, various omissions, substitutions, or modifications of the components can be made without departing from the spirit of the above-described embodiments.

[0218] The charging device is not limited to being used to charge the battery of an electric two-wheeled vehicle, but may also be used to charge the battery of an electric power unit, for example. [Explanation of symbols]

[0219] 1, 1A charging device 2 AC power supply 3. Fuse 4 Common mode filters 5 Battery 11 Rectifier circuit 12, 12-1, 12-2 Boost / Down Pressure Rate Improvement Circuit 13, 13-1, 13-2 Isolated converter 14 Output Filter 15 Control Unit 15a AD conversion section 15b Communication Department 15c, 15m subtractor 15d Input voltage instantaneous value output section 15e Input current instantaneous value output section 15f DC link voltage average value output section 15g DC link voltage instantaneous value output section 15h Output voltage average value output section 15i Output voltage instantaneous value output section 15j Output current instantaneous value output section 15k Boost / Down Pressure Rate Improvement Circuit Control Unit 15l Active current indication value calculation section 15n Target DC link voltage calculation section 15o Isolated converter control unit 15p Duty calculation section 15q, 15s Switching control signal output section 15r Phase control amount calculation section 51, 52 Power conversion circuit

Claims

1. A charging device for charging a battery, a rectifier circuit that rectifies an AC voltage and outputs a rectified voltage; a step-up / step-down voltage factor improvement circuit that steps up or steps down the rectified voltage and outputs a first DC voltage; an isolated converter that converts the first DC voltage and outputs a second DC voltage to the battery; a control unit that controls the step-up / step-down voltage factor improvement circuit to step up or step down the rectified voltage based on the AC voltage and the first DC voltage; Including, A battery charging device comprising:

2. The control unit setting a first threshold value and a second threshold value based on the first DC voltage; When the AC voltage is equal to or greater than the first threshold value or less than the second threshold value, the step-up / step-down voltage factor improvement circuit is controlled to step down the rectified voltage; controlling the step-up / step-down voltage factor improvement circuit to step up the rectified voltage when the AC voltage is less than the first threshold value and equal to or greater than the second threshold value; 2. The battery charging device according to claim 1.

3. The control unit controlling the boost / buck voltage factor improvement circuit to boost the rectified voltage when an absolute value of a difference between a positive peak value of the AC voltage and a first DC voltage target value that is a target value of the first DC voltage is less than a predetermined third threshold value; 3. The battery charging device according to claim 2.

4. The control unit controlling the step-up / step-down voltage factor improvement circuit to step up the rectified voltage when an absolute value of a difference between a positive peak value of the AC voltage and an average value of the first DC voltage is less than a fourth predetermined threshold value; 3. The battery charging device according to claim 2.

5. The control unit when controlling the step-up / step-down voltage factor improvement circuit to step up the rectified voltage, a predetermined correction value is added to a first DC voltage target value, which is a target value of the first DC voltage, so that the first DC voltage target value is made larger than a positive peak value of the AC voltage; 5. The battery charging device according to claim 3 or 4.

6. a plurality of power conversion circuits each including the boost / buck voltage factor improvement circuit and the isolated converter are connected in parallel; The control unit The plurality of power conversion circuits are operated in an interleaved manner.

2. The battery charging device according to claim 1.

7. A control method for a battery charging device including a rectifier circuit that rectifies an AC voltage and outputs a rectified voltage, a step-up / step-down voltage factor improvement circuit that steps up or steps down the rectified voltage and outputs a first DC voltage, and an isolated converter that converts the first DC voltage and outputs a second DC voltage to a battery, controlling the step-up / step-down voltage factor improvement circuit so as to step up or step down the rectified voltage based on the AC voltage and the first DC voltage; A control method comprising:

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