Power supply device

Abstract

To provide a power supply device capable of outputting AC power during charging of a battery.SOLUTION: The power supply device 1 includes the first leg 11 having the first switching device S1 and the second switching device S2, the second leg 12 having the third switching device S3 and the fourth switching device S4, and the third leg 13 having the fifth switching device S5 and the sixth switching device S6. When AC power is supplied across a first node S1 between the first switching device S2 and the second switching device 11N and a second node S3 between the third switching device S4 and the fourth switching device 12N, DC power used to charge the battery is outputted across the first power source line 2 and the second power source line 3, and at the same time, another AC power based on the AC power is outputted across the second node 12N and a third node S5 between the fifth switching device S6 and the sixth switching device. 13N.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a power supply device that charges a battery mounted on a vehicle. [Background technology]

[0002] In recent years, automobiles equipped with a motor as a driving source (such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), battery electric vehicles (BEVs), and fuel cell electric vehicles (FCEVs)) have become widespread. These automobiles are equipped with batteries that are configured to be charged using AC power supplied from an external source. While charging such batteries, it may be desirable to use AC power. Technologies that can realize such usage patterns are described, for example, in Patent Documents 1 and 2, the sources of which are shown below.

[0003] Patent Document 1 describes a charger for charging a battery. This charger includes a power factor correction circuit connected to AC power, a DC conversion circuit connected at one end to the power factor correction circuit and at the other end to a battery, and an AC conversion circuit that receives power and outputs AC power. The power factor correction circuit, the DC conversion circuit, and the AC conversion circuit are each configured as separate entities.

[0004] Patent Document 2 describes a power supply device that can charge a main battery and an auxiliary battery with a lower voltage than the main battery using a system power supply. This power supply device is equipped with a plug that can be connected to an outlet of the system power supply and an outlet that can be connected to the plugs of home appliances. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Publication No. 2017-158322 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-312395 Summary of the Invention [Problem to be solved by the invention]

[0006] As described above, the charger described in Patent Document 1 has a DC conversion circuit used to charge the battery and an AC conversion circuit that outputs AC power, which are provided separately. This increases the number of components used in the DC conversion circuit and the AC conversion circuit, leading to increased costs, an increase in the size of the device, and reduced efficiency. Furthermore, the power supply device described in Patent Document 2 uses a switch to switch between the plug and the outlet, and it is not possible to extract (output) AC power from the outlet while the battery is being charged.

[0007] Therefore, there is a demand for a power supply device that has a small number of parts and is capable of outputting AC power while the battery is being charged. [Means for solving the problem]

[0008] A characteristic configuration of a power supply device according to the present invention is a power supply device that charges a battery mounted on a vehicle, the power supply device comprising: a first leg that is provided across a first power supply line and a second power supply line and has a first high-side switching element and a second low-side switching element connected in series; a second leg that is provided across the first power supply line and the second power supply line and has a third high-side switching element and a fourth low-side switching element connected in series; and a third leg that is provided across the first power supply line and the second power supply line and has a fifth high-side switching element and a sixth low-side switching element connected in series; when AC power is supplied across a first node between the first switching element and the second switching element and a second node between the third switching element and the fourth switching element, the power supply device outputs DC power used to charge the battery across the first power supply line and the second power supply line, and simultaneously outputs another AC power based on the AC power across the second node and a third node between the fifth switching element and the sixth switching element.

[0009] With this characteristic configuration, electrical appliances and devices that operate on AC power can be used while the battery is being charged. Furthermore, since the third leg is used both to output DC power used to charge the battery based on the AC power supplied across the first node and the second node and to output other AC power based on the AC power supplied across the first node and the second node, the number of components used can be reduced compared to when the third leg is not used. Therefore, a power supply device with a reduced number of components and capable of outputting AC power while the battery is being charged can be realized. Furthermore, by controlling the drive of the fifth switching element and the sixth switching element of the third leg in accordance with the phase of the AC voltage in the AC power supplied across the first node and the second node, a current can be passed in both directions between the second node and the third node. Therefore, even when a load (such as an inductive load or a capacitive load) with a power factor other than unity is connected across the second node and the third node, a reactive current can be passed between the power supply device and the load. [Brief explanation of the drawings]

[0010] [Figure 1] FIG. 2 is a circuit diagram of a power supply device. [Figure 2] 3A and 3B are diagrams showing waveforms at various parts of the power supply device; [Figure 3] FIG. 4 is a diagram showing a current flowing through the power supply device in a first state. [Figure 4] FIG. 4 is a diagram showing a current flowing through the power supply device in a first state. [Figure 5] FIG. 10 is a diagram showing the current flowing through the power supply device in a second state. [Figure 6] FIG. 10 is a diagram showing the current flowing through the power supply device in a second state. [Figure 7] FIG. 4 is a diagram showing a current flowing through the power supply device in a first state. [Figure 8] FIG. 4 is a diagram showing a current flowing through the power supply device in a first state. [Figure 9] FIG. 10 is a diagram showing the current flowing through the power supply device in a second state. [Figure 10]FIG. 10 is a diagram showing the current flowing through the power supply device in a second state. [Figure 11] FIG. 2 is a diagram showing the relationship between a system voltage and a system current. [Figure 12] FIG. 2 is a diagram showing the relationship between a system voltage and a system current. DETAILED DESCRIPTION OF THE INVENTION

[0011] A power supply device according to the present invention is mounted on a vehicle and configured to be able to charge a battery mounted on the vehicle and output AC power at the same time. The power supply device 1 of this embodiment will be described below. However, the power supply device 1 is not limited to the following embodiment and various modifications are possible without departing from the spirit of the invention.

[0012] Fig. 1 is a circuit diagram of power supply device 1. As shown in Fig. 1, power supply device 1 is configured to include a first leg 11, a second leg 12, and a third leg 13. Fig. 1 also shows a supply unit 4 that supplies AC power to power supply device 1, an output unit 5 that outputs AC power from power supply device 1, a first reactor coil L1, a second reactor coil L2, a capacitor C, and a control unit 6. Each functional unit is constructed using hardware or software, or both, with a CPU as its core component, in order to perform the processes related to the charging of the battery and the output of AC power described above.

[0013] In the power supply device 1, AC power is supplied from an external power source 50 to the supply unit 4, and the power supply device 1 converts this AC power into DC power capable of charging a battery and outputs the converted power. Furthermore, simultaneously with the output of the DC power, AC power corresponding to the supplied AC power is output from the output unit 5. For example, a load 60 is connected to the output unit 5, and AC power is supplied from the output unit 5 to this load 60. "Connection" means an electrical connection that allows power supply, and in the following description, "electrical connection" will be simply referred to as "connection." Furthermore, in the following description, for ease of understanding, the AC power supplied from the supply unit 4 will be referred to as grid power.

[0014] Grid power refers to power composed of an AC voltage whose voltage value oscillates at a predetermined cycle. Specifically, AC voltage oscillates at a commercial frequency (e.g., 50 Hz or 60 Hz) and corresponds to an AC voltage of 200 V (effective value) extracted from a commercial power supply supplied by a single-phase three-wire system. DC power refers to power composed of a DC voltage that has a constant voltage value (excluding ripple voltage) relative to a reference voltage. Power supply device 1 converts grid power composed of such AC voltage into DC power composed of a DC voltage. Power supply device 1 has a pair of output terminals 10A and 10B. Output terminal 10A is used as a positive terminal, and output terminal 10B is used as a negative terminal. The DC power converted by power supply device 1 is output from this pair of output terminals 10A and 10B.

[0015] The first power supply line 2 is connected to the output terminal 10A, and the second power supply line 3 is connected to the output terminal 10B. The first leg 11, the second leg 12, and the third leg 13 are provided across the first power supply line 2 and the second power supply line 3, respectively. Therefore, the first leg 11, the second leg 12, and the third leg 13 are provided in parallel with each other to the first power supply line 2 and the second power supply line 3. As a result, one end 11A of the first leg 11, one end 12A of the second leg 12, and one end 13A of the third leg 13 are connected to the output terminal 10A, and the other end 11B of the first leg 11, the other end 12B of the second leg 12, and the other end 13B of the third leg 13 are connected to the output terminal 10B.

[0016] The first leg 11 includes a high-side first switching element S1 and a low-side second switching element S2 connected in series. In this embodiment, the first switching element S1 and the second switching element S2 are configured using n-type metal-oxide-semiconductor field-effect transistors (MOS-FETs). The drain terminal of the first switching element S1 is connected to the end 11A, and the source terminal is connected to the drain terminal of the second switching element S2. The source terminal of the second switching element S2 is connected to the end 11B. The gate terminals of the first switching element S1 and the second switching element S2 are connected to the control unit 6. Diodes D1 and D2 are provided between the source terminals and drain terminals of the first switching element S1 and the second switching element S2, with the anode terminals connected to the source terminals and the cathode terminals connected to the drain terminals.

[0017] The second leg 12 also includes a high-side third switching element S3 and a low-side fourth switching element S4 connected in series. In this embodiment, the third switching element S3 and the fourth switching element S4 are also n-type MOS-FETs. The drain terminal of the third switching element S3 is connected to the end 12A, and the source terminal is connected to the drain terminal of the fourth switching element S4. The source terminal of the fourth switching element S4 is connected to the end 12B. The gate terminals of the third switching element S3 and the fourth switching element S4 are connected to the control unit 6. Diodes D3 and D4 are provided between the source terminals and drain terminals of the third switching element S3 and the fourth switching element S4, with the anode terminals connected to the source terminals and the cathode terminals connected to the drain terminals.

[0018] The third leg 13 further includes a high-side fifth switching element S5 and a low-side sixth switching element S6 connected in series. In this embodiment, n-type MOS-FETs are also used for the fifth switching element S5 and the sixth switching element S6. The fifth switching element S5 has a drain terminal connected to the end 13A and a source terminal connected to the drain terminal of the sixth switching element S6. The source terminal of the sixth switching element S6 is connected to the end 13B. The gate terminals of the fifth switching element S5 and the sixth switching element S6 are connected to the control unit 6. Diodes D5 and D6 are provided between the source terminals and drain terminals of the fifth switching element S5 and the sixth switching element S6, with the anode terminals connected to the source terminals and the cathode terminals connected to the drain terminals.

[0019] A capacitor C is provided across output terminal 10A and output terminal 10B. Capacitor C smoothes the DC voltage output from power supply device 1.

[0020] One terminal L1B of the first reactor coil L1 is connected to a first node 11N between the first switching element S1 and the second switching element S2. The first node 11N between the first switching element S1 and the second switching element S2 is a node connected to the source terminal of the first switching element S1 and the drain terminal of the second switching element S2. Such a node may be provided, for example, on a line (e.g., a wiring pattern on a circuit board or a cable such as a harness) connecting the source terminal of the first switching element S1 and the drain terminal of the second switching element S2. Of course, it may also be the source terminal of the first switching element S1 or the drain terminal of the second switching element S2. The other terminal L1A of the first reactor coil L1 is connected to the supply unit 4.

[0021] Grid power is supplied between the other terminal L1A of the first reactor coil L1 and a second node 12N between the third switching element S3 and the fourth switching element S4. As described above, one terminal L1B of the first reactor coil L1 is connected to the first node 11N. The second node 12N between the third switching element S3 and the fourth switching element S4 is a node connected to the source terminal of the third switching element S3 and the drain terminal of the fourth switching element S4. Such a node may be provided, for example, on a line (e.g., a wiring pattern on a circuit board or a cable such as a harness) connecting the source terminal of the third switching element S3 and the drain terminal of the fourth switching element S4. Of course, it may also be the source terminal of the third switching element S3 or the drain terminal of the fourth switching element S4. Therefore, in the power supply device 1, grid power is supplied between the first node 11N and the second node 12N.

[0022] The power supply device 1 converts grid power into DC power using a first switching element S1 and a second switching element S2 in the first leg 11 and a third switching element S3 and a fourth switching element S4 in the second leg 12. The converted DC power is used to charge the battery and is output across the first power supply line 2 and the second power supply line 3.

[0023] One terminal L2B of the second reactor coil L2 is connected to a third node 13N between the fifth switching element S5 and the sixth switching element S6. The third node 13N between the fifth switching element S5 and the sixth switching element S6 is a node connected to the source terminal of the fifth switching element S5 and the drain terminal of the sixth switching element S6. Such a node may be provided, for example, on a line (e.g., a wiring pattern on a circuit board or a cable such as a harness) connecting the source terminal of the fifth switching element S5 and the drain terminal of the sixth switching element S6. Of course, the node may also be the source terminal of the fifth switching element S5 or the drain terminal of the sixth switching element S6. The other terminal L2A of the second reactor coil L2 is connected to the output unit 5.

[0024] Another AC power based on the grid power is output between the other terminal L2A of the second reactor coil L2 and the second node 12N. One terminal L2B of the second reactor coil L2 is connected to the third node 13N. In this embodiment, the grid power is AC power having a grid voltage of 200 V (effective value). The other AC power is AC power generated by converting such grid power. In this embodiment, this corresponds to AC power having an AC voltage of 100 V (effective value), for example. Therefore, the power supply device 1 outputs AC power having an AC voltage of a predetermined voltage value (for example, 100 V (effective value)) between the second node 12N and the third node 13N.

[0025] When system power is supplied to supply unit 4, power supply device 1 is configured to output DC power used to charge the battery across a pair of output terminals 10A, 10B, and simultaneously output AC power from output unit 5. As described above, AC power consisting of an AC voltage of 200 V (effective value) is supplied to supply unit 4, but an AC voltage of 100 V (effective value) is output from output unit 5. Therefore, power supply device 1 makes it possible to use 100 V electrical appliances and electrical devices while the battery is being charged.

[0026] The supply unit 4 of the power supply device 1 is supplied with system power consisting of a system voltage (200 V (effective value) in the example of FIG. 2) as shown in FIG. 2A. The first leg 11 and the second leg 12 are switched between a first state and a second state by the control unit 6. In the first state, when the system voltage is at a positive potential, the first switching element S1 and the second switching element S2 are alternately closed and the fourth switching element S4 is closed (see FIGS. 2B, 2C, and 2E). In this first state, the third switching element S3 is opened (see FIG. 2D).

[0027] In this first state, a state in which current flows through the supply unit 4, the first reactor coil L1, the first switching element S1, and the fourth switching element S4 as shown in Figure 3, and a state in which current flows through the supply unit 4, the first reactor coil L1, the second switching element S2, and the fourth switching element S4 as shown in Figure 4 are repeated.

[0028] In the second state, when the system voltage is negative, the first switching element S1 and the second switching element S2 are alternately closed, and the third switching element S3 is closed (see (B), (C), and (D) in FIG. 2). In this second state, the fourth switching element S4 is opened (see (E) in FIG. 2).

[0029] In this second state, a state in which current flows through the supply unit 4, the third switching element S3, the second switching element S2, and the first reactor coil L1 as shown in Figure 5, and a state in which current flows through the supply unit 4, the third switching element S3, the first switching element S1, and the first reactor coil L1 as shown in Figure 6 are repeated.

[0030] In this embodiment, the control unit 6 alternately drives the first switching element S1 and the second switching element S2 of the first leg 11 at a predetermined frequency (a frequency higher than the grid frequency), and alternately drives the third switching element S3 and the fourth switching element S4 of the second leg 12 at the grid frequency (see FIG. 2). That is, the third switching element S3 and the fourth switching element S4 of the second leg 12 are driven at a frequency lower than the frequency at which the first switching element S1 and the second switching element S2 of the first leg 11 are driven, depending on the phase of the grid voltage. This enables the power supply device 1 to convert grid power into DC power based on the first switching element S1 and the second switching element S2 of the first leg 11 and the third switching element S3 and the fourth switching element S4 of the second leg 12 (see (H) of FIG. 2).

[0031] Furthermore, while the control unit 6 alternately drives the third switching element S3 and the fourth switching element S4 of the second leg 12 at the grid frequency, the control unit 6 also alternately drives the fifth switching element S5 and the sixth switching element S6 of the third leg 13 (see (F) and (G) in FIG. 2). The fifth switching element S5 and the sixth switching element S6 are alternately driven at a frequency higher than the grid frequency. In this embodiment, the fifth switching element S5 and the sixth switching element S6 are driven at the same frequency as the frequency at which the first switching element S1 and the second switching element S2 are driven.

[0032] In the first state, current is controlled to flow in both directions from the output unit 5, such as in a state in which current flows through the output unit 5, the fourth switching element S4, the fifth switching element S5, and the second reactor coil L2 as shown in Figure 7, and in a state in which current flows through the output unit 5, the second reactor coil L2, the sixth switching element S6, and the fourth switching element S4 as shown in Figure 8.

[0033] In the second state, current is controlled to flow in both directions from the output unit 5, such as in a state where current flows through the output unit 5, the second reactor coil L2, the sixth switching element S6, and the third switching element S3 as shown in Figure 9, and in a state where current flows through the output unit 5, the third switching element S3, the fifth switching element S5, and the second reactor coil L2 as shown in Figure 10.

[0034] This allows the power supply device 1 to convert the grid power supplied to the supply unit 4 into AC power different from the grid power. Specifically, when charging the battery, an AC voltage of 200 V (effective value) is applied to the power supply device 1, but an AC voltage of 100 V (effective value) can be output from the output unit 5 (see (I) in FIG. 2). Furthermore, by alternately driving the fifth switching element S5 and the sixth switching element S6 of the third leg 13, the output unit 5 can be charged and discharged without discharging the supply unit 4. Even when the output unit 5 is connected to a load 60 with a power factor other than unity, such as an inductive load such as a motor, transformer, or relay, or a capacitive load with a smoothing circuit equipped with a large-capacity capacitor, reactive current can flow bidirectionally through the output unit 5. Furthermore, because the second leg 12 and the third leg 13 used to output AC power are configured with MOS-FETs, the current output from the output unit 5 can be a sine wave with minimal distortion. This reduces electromagnetic noise and abnormal sounds from the load 60.

[0035] As described above, in the power supply device 1, the third leg 13 is used for both outputting (converting) DC power and outputting (converting) AC power. As described above, the control unit 6 drives the fifth switching element S5 and the sixth switching element S6 of the third leg 13 in accordance with the voltage phase of the grid power. That is, when the voltage value of the grid voltage is positive (phase is 0-180 degrees), the control unit 6 opens the third switching element S3 and closes the fourth switching element S4, and when the voltage value of the grid voltage is negative (phase is 180-360 degrees), the control unit 6 closes the third switching element S3 and closes the fourth switching element S4.

[0036] 2A shows a voltage waveform of the grid voltage (effective value: 200 V) constituting the grid power supplied to the supply unit 4. FIG. 2B shows a signal input to the gate terminal of the first switching element S1 of the first leg 11, and FIG. 2C shows a signal input to the gate terminal of the second switching element S2 of the first leg 11. FIG. 2D shows a signal input to the gate terminal of the third switching element S3 of the second leg 12, and FIG. 2E shows a signal input to the gate terminal of the fourth switching element S4 of the second leg 12. FIG. 2F shows a signal input to the gate terminal of the fifth switching element S5 of the third leg 13, and FIG. 2G shows a signal input to the gate terminal of the sixth switching element S6 of the third leg 13. 2(H) shows the voltage waveform of the DC voltage (maximum value: 282.8 V) constituting the DC power output from the pair of output terminals 10A and 10B. FIG. 2(I) shows the voltage waveform of the AC voltage (effective value: 100 V) constituting the AC power output from output unit 5.

[0037] As shown in (D) and (E) of Figure 2, the control unit 6 drives the third switching element S3 and the fourth switching element S4 of the second leg 12 at the same frequency (e.g., 50 Hz or 60 Hz) as the frequency of the system power supplied to the supply unit 4 and the frequency of the AC power output from the output unit 5, and as shown in (B), (C), (F), and (G) of Figure 2, the control unit 6 drives the first switching element S1 and the second switching element S2 of the first leg 11 and the fifth switching element S5 and the sixth switching element S6 of the third leg 13 by PWM control at a control frequency (e.g., several hundred kHz) that enables the power supply device 1 to convert DC power to charge a battery and output AC power that can be used to power electrical appliances via the output unit 5. This makes it possible to output DC power that can be used to charge the battery, as shown in (H) of Figure 2, and at the same time output an AC voltage (as shown in (I) of Figure 2) from the output unit 5, which has a voltage value different from the voltage value of the AC voltage input to the supply unit 4, as shown in (A) of Figure 2.

[0038] The on-duty ratios of the signal input to the gate terminal of the fifth switching element S5 of the third leg 13 shown in FIG. 2(F) and the signal input to the gate terminal of the sixth switching element S6 of the third leg 13 shown in FIG. 2(G) may be changed according to the AC power output from the output unit 5 (or according to the power consumption).

[0039] Here, the first state and the second state are switched based on the sensing result of sensing the voltage value of the grid voltage. This sensing of the voltage value is performed in response to a sensing command to sense the voltage value of the grid voltage from the control unit 6. However, for example, due to variations in the characteristics of elements used in the power supply device 1, a difference may occur between the timing when the sensing command is issued and the timing when the sensing result is acquired based on the sensing command.

[0040] In addition, switching from one of the first state and the second state to the other is performed in response to a switching command from the control unit 6, but there may be a difference between the timing when the switching command is received from the control unit 6 and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switching command.

[0041] 11, even though the system voltage is at a positive potential between t0 and t1, the power supply device 1 may discharge to the system side (the system current has a negative value). Such discharge from the power supply device 1 to the system side often occurs when the system voltage is close to zero volts (near a zero crossing). Therefore, in the power supply device 1, it is preferable that the first leg 11 and the second leg 12 stop switching between the first state and the second state when the voltage value of the system voltage in the system power supplied across the first node 11N and the second node 12N is within a predetermined range set with zero volts as the reference.

[0042] The period during which switching between the first state and the second state is stopped is preferably set based on a time corresponding to the difference between the timing when the sensing command was issued and the timing when the sensing result was acquired based on the sensing command, and a time corresponding to the difference between the timing when the switching command was issued and the timing when the states of the first leg 11 and the second leg 12 were switched based on the switching command. That is, at the design stage, the time corresponding to the difference between the timing when the sensing command was issued and the timing when the sensing result was acquired based on the sensing command, and the time corresponding to the difference between the timing when the switching command was issued and the timing when the states of the first leg 11 and the second leg 12 were switched based on the switching command are calculated, and switching between the first state and the second state is stopped for the calculated time range around the zero-crossing point (the point in time when the grid voltage becomes zero volts: t0).

[0043] As a result, as shown in FIG. 12, it is possible to prevent discharge from the power supply device 1 to the system side near the zero crossing of the system voltage (between t2 and t3).

[0044] Furthermore, while the switching between the first state and the second state is stopped near the zero crossing of the system voltage (between t2 and t3), it is preferable that the second leg 12 and the third leg 13 are switched between the third state and the fourth state by the control unit 6.

[0045] In the third state, the fourth switching element S4 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed. In this third state, the third switching element S3 is open. Therefore, in the third state, the power supply is switched between a state in which a current flows through the output unit 5, the fourth switching element S4, the fifth switching element S5, and the second reactor coil L2 as shown in FIG. 7, and a state in which a current flows through the output unit 5, the second reactor coil L2, the sixth switching element S6, and the fourth switching element S4 as shown in FIG.

[0046] In the fourth state, the third switching element S3 is closed, and the fifth switching element S5 and the sixth switching element S6 are alternately closed. In this fourth state, the fourth switching element S4 is open. Therefore, in the fourth state, the power supply is switched between a state in which a current flows through the output unit 5, the second reactor coil L2, the sixth switching element S6, and the third switching element S3, as shown in FIG. 9, and a state in which a current flows through the output unit 5, the third switching element S3, the fifth switching element S5, and the second reactor coil L2, as shown in FIG. 10.

[0047] This allows a positive current and a negative current to flow in the output unit 5. That is, in the output unit 5, it becomes possible to flow a current from the power supply device 1 to the load 60 side and a current from the load 60 side to the power supply device 1 (current can flow in both directions).

[0048] Other Embodiments Next, other embodiments of the power supply device 1 will be described.

[0049] In the above embodiment, the first switching element S1, the second switching element S2, the third switching element S3, the fourth switching element S4, the fifth switching element S5, and the sixth switching element S6 are described as being configured using n-type MOS-FETs. However, the first switching element S1, the second switching element S2, the third switching element S3, the fourth switching element S4, the fifth switching element S5, and the sixth switching element S6 may be configured using p-type MOS-FETs. Furthermore, the first switching element S1, the second switching element S2, the third switching element S3, the fourth switching element S4, the fifth switching element S5, and the sixth switching element S6 may be configured using bipolar transistors or IGBTs (Insulated Gate Bipolar Transistors).

[0050] In the above embodiment, it has been described that the first leg 11 and the second leg 12 stop switching between the first state and the second state when the voltage value of the system voltage in the system power supplied across the first node 11N and the second node 12N is within a predetermined range set around zero volts. However, it is also possible to configure the first leg 11 and the second leg 12 so as not to stop switching between the first state and the second state even when the voltage value of the system voltage in the system power supplied across the first node 11N and the second node 12N is within a predetermined range set around zero volts.

[0051] In the above embodiment, it has been described that the period during which switching between the first state and the second state is stopped is set based on the time corresponding to the difference between the timing when a sensing command to sense the voltage value of the grid voltage is issued and the timing when the sensing result is obtained based on the sensing command, and the time corresponding to the difference between the timing when a switch command from one of the first state and the second state to the other is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switch command. However, it is also possible to set the period during which switching between the first state and the second state is stopped based on either the time corresponding to the difference between the timing when a sensing command to sense the voltage value of the grid voltage is issued and the timing when the sensing result is obtained based on the sensing command, or the time corresponding to the difference between the timing when a switch command from one of the first state and the second state to the other is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switch command. In addition, the period during which switching between the first state and the second state is stopped can also be set based on conditions other than the time corresponding to the difference between the timing when a sensing command to sense the voltage value of the system voltage is issued and the timing when the sensing result is obtained based on the sensing command, and the time corresponding to the difference between the timing when a command to switch from one of the first state and the second state to the other is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switching command.

[0052] In the above embodiment, while the switching between the first state and the second state is stopped, the second leg 12 and the third leg 13 are switched between a third state in which the fourth switching element S4 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed, and a fourth state in which the third switching element S3 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed. However, while the switching between the first state and the second state is stopped, the second leg 12 and the third leg 13 may be configured to be driven in a state other than the third state in which the fourth switching element S4 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed, and the fourth state in which the third switching element S3 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed.

[0053] [Summary of the above embodiment] The power supply device 1 described above will now be outlined.

[0054] (1) The power supply device 1 is a power supply device 1 for charging a battery mounted on a vehicle, and includes a first leg 11 provided across a first power supply line 2 and a second power supply line 3 and having a high-side first switching element S1 and a low-side second switching element S2 connected in series to each other, a second leg 12 provided across the first power supply line 2 and the second power supply line 3 and having a high-side third switching element S3 and a low-side fourth switching element S4 connected in series to each other, and a high-side fifth switching element S5 provided across the first power supply line 2 and the second power supply line 3 and having a high-side fifth switching element S6 and a low-side fifth switching element S7 connected in series to each other. and a third leg 13 having a low-side sixth switching element S5 and a low-side sixth switching element S6, and when AC power is supplied across a first node 11N between the first switching element S1 and the second switching element S2 and a second node 12N between the third switching element S3 and the fourth switching element S4, DC power used to charge the battery is output across the first power supply line 2 and the second power supply line 3, and at the same time, other AC power based on the AC power is output across the second node 12N and a third node 13N between the fifth switching element S5 and the sixth switching element S6.

[0055] This configuration allows electrical appliances and devices that operate on AC power to be used while the battery is being charged. Furthermore, the third leg 13 is used both to output DC power used to charge the battery based on the AC power supplied across the first node 11N and the second node 12N and to output other AC power based on the AC power supplied across the first node 11N and the second node 12N. This reduces the number of components used compared to when the third leg 13 is not used. This allows for a power supply device 1 that has a reduced number of components and is capable of outputting AC power while the battery is being charged. Furthermore, by controlling the driving of the fifth switching element S5 and the sixth switching element S6 of the third leg 13 in accordance with the phase of the AC voltage of the AC power supplied across the first node 11N and the second node 12N, a current can be passed bidirectionally between the second node 12N and the third node 13N. Therefore, even if a load 60 (an inductive load or a capacitive load) having a power factor other than 1 is connected across the second node 12N and the third node 13N, it is possible to pass a reactive current between the power supply device 1 and the load 60.

[0056] (2) In the power supply device 1 described in (1), the first leg 11 and the second leg 12 are switched between a first state in which the first switching element S1 and the second switching element S2 are alternately closed and the fourth switching element S4 is closed, and a second state in which the first switching element S1 and the second switching element S2 are alternately closed and the third switching element S3 is closed. It is preferable that the first leg 11 and the second leg 12 stop switching between the first state and the second state when the voltage value of the AC voltage in the AC power supplied across the first node 11N and the second node 12N is within a predetermined range set with zero volts as the reference.

[0057] If the first switching element S1 and the second switching element S2 of the first leg 11 and the third switching element S3 and the fourth switching element S4 of the second leg 12 are not driven appropriately, for example, even if the AC voltage in the AC power supplied across the first node 11N and the second node 12N is at a positive potential, the current flowing across the first node 11N and the second node 12N may become negative, causing the power supply device 1 to discharge to the supply side of the AC power. Such discharge to the supply side often occurs when the AC voltage is close to zero volts (near a zero crossing). Therefore, by stopping switching between the first state and the second state when the AC voltage is within a predetermined range set based on zero volts as in the above configuration, it is possible to prevent discharge to the supply side of the AC power.

[0058] (3) In the power supply device 1 described in (2), the period during which switching between the first state and the second state is stopped is preferably set based on a time corresponding to the difference between the timing when a sensing command to sense the voltage value of the AC voltage is issued and the timing when the sensing result is obtained based on the sensing command, and a time corresponding to the difference between the timing when a command to switch from one of the first state and the second state to the other is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switching command.

[0059] When switching between the first state and the second state for the first leg 11 and the second leg 12 based on the sensing result of sensing the voltage value of the AC voltage in the AC power supplied across the first node 11N and the second node 12N, the sensing of the voltage value is performed in response to a sensing command. However, there may be a difference between the timing when the sensing command is issued and the timing when the sensing result is acquired based on the sensing command. Furthermore, switching between the first state and the second state is performed in response to a switching command. However, there may be a difference between the timing when the switching command is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switching command. Therefore, according to the above configuration, for example, at the design stage, the time corresponding to the difference between the timing when a sensing command is issued and the timing when the sensing result is obtained based on the sensing command, and the time corresponding to the difference between the timing when a switching command is issued and the timing when the states of the first leg 11 and the second leg 12 are switched based on the switching command are calculated, and the switching between the first state and the second state is stopped for the calculated time around the point when the voltage value of the AC voltage becomes zero volts, so that discharging from the power supply device 1 to the AC power supply side can be prevented for that time.

[0060] (4) In the power supply device 1 described in (2) or (3), while the switching between the first state and the second state is stopped, it is preferable that the second leg 12 and the third leg 13 be switched between a third state in which the fourth switching element S4 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed, and a fourth state in which the third switching element S3 is closed and the fifth switching element S5 and the sixth switching element S6 are alternately closed.

[0061] According to this configuration, even while the switching between the first state and the second state is stopped, it is possible to continue outputting other AC power from the AC power supplied across the first node 11N and the second node 12N. [Industrial Applicability]

[0062] The technology according to the present disclosure can be used in a power supply device that charges a battery mounted on a vehicle. [Explanation of symbols]

[0063] 1: power supply unit, 2: first power line, 3: second power line, 11: first leg, 11N: first node, 12: second leg, 12N: second node, 13N: third node, 13: third leg, S1: first switching element, S2: second switching element, S3: third switching element, S4: fourth switching element, S5: fifth switching element, S6: sixth switching element

Claims

1. A power supply device that charges a battery mounted on a vehicle, a first leg provided across the first power supply line and the second power supply line and having a first high-side switching element and a second low-side switching element connected in series with each other; a second leg provided across the first power supply line and the second power supply line and including a third high-side switching element and a fourth low-side switching element connected in series to each other; a third leg provided across the first power supply line and the second power supply line, the third leg including a fifth high-side switching element and a sixth low-side switching element connected in series to each other; a power supply device that, when AC power is supplied across a first node between the first switching element and the second switching element and a second node between the third switching element and the fourth switching element, outputs DC power to be used for charging the battery across the first power supply line and the second power supply line, and simultaneously outputs another AC power based on the AC power across the second node and a third node between the fifth switching element and the sixth switching element.

2. the first leg and the second leg are switched between a first state in which the first switching element and the second switching element are alternately brought into a closed state and the fourth switching element is brought into a closed state, and a second state in which the first switching element and the second switching element are alternately brought into a closed state and the third switching element is brought into a closed state; 2. The power supply device according to claim 1, wherein the first leg and the second leg stop switching between the first state and the second state when a voltage value of an AC voltage in the AC power supplied across the first node and the second node is within a predetermined range set based on zero volts.

3. 3. The power supply device according to claim 2, wherein a period during which switching between the first state and the second state is stopped is set based on a time corresponding to a difference between a timing when a sensing command to sense the voltage value of the AC voltage is issued and a timing when a sensing result is acquired based on the sensing command, and a time corresponding to a difference between a timing when a command to switch from one of the first state and the second state to the other is issued and a timing when the states of the first leg and the second leg are switched based on the switching command.

4. 4. The power supply device according to claim 2, wherein, while switching between the first state and the second state is stopped, the second leg and the third leg are switched between a third state in which the fourth switching element is closed and the fifth switching element and the sixth switching element are alternately closed, and a fourth state in which the third switching element is closed and the fifth switching element and the sixth switching element are alternately closed.

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