Charging system

Abstract

To charge an electric vehicle by making effective use of available power without tripping a main circuit breaker.SOLUTION: A charging system electrically connects an electric vehicle equipped with a storage battery to a consumer via a charging cable to charge the storage battery. The charging system obtains a power measurement value obtained by measuring power based on current flowing at a power receiving point of the consumer and voltage applied to the power receiving point and a predetermined receiving power target value, successively updates a charge power target value of the storage battery on the basis of the acquired power measurement value and the receiving power target value.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a charging system. [Background technology]

[0002] In recent years, plug-in hybrid vehicles (PHEVs) and electric vehicles (EVs) have begun to become more common. Electric vehicles, in particular, require a large amount of charging power because they run solely on electricity. Charging is often performed in the parking lot of the user's home by attaching a connector at the end of a charging cable connected to indoor wiring to the electric vehicle (see, for example, Patent Document 1). Furthermore, with regard to charging of electric vehicles, it has been considered to set a certain charging power in consideration of various conditions and charge the vehicle (see, for example, Patent Document 2). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-128180 [Patent Document 2] Japanese Patent Application Laid-Open No. 2008-136291 Summary of the Invention [Problem to be solved by the invention]

[0004] Electricity consumers, such as ordinary households, often have contracts with electric power companies for a single-phase, three-wire system, for example, around 6 kVA. The main breaker in the distribution panel has a current rating that matches the contracted power. If the consumer's power consumption increases and exceeds the current rating, the main breaker trips according to a predetermined time-delay characteristic. For example, if a consumer is operating a large number of household appliances that consume relatively large amounts of power, such as air conditioners, and an electric vehicle, which consumes a certain amount of power, is being charged, the main breaker may trip.

[0005] Furthermore, as electric vehicles become more widespread, there is a possibility that many electric vehicles will be charged simultaneously in a nearby area. In this case, the voltage of the distribution system will drop due to voltage drops caused by line impedance. On the other hand, if the charging power of electric vehicles is limited to a low, fixed value, the power that could have been used will not be used, and there is a possibility that electric vehicles will not be fully charged.

[0006] In view of the above problems, an object of the present invention is to charge an electric vehicle without tripping a main breaker and by effectively utilizing available power. [Means for solving the problem]

[0007] The present disclosure includes the following inventions, which are defined by the claims.

[0008] A power storage system according to one embodiment of the present invention is a power storage system that electrically connects an electric vehicle equipped with a storage battery to a consumer via a charging cable, and includes a power measurement unit that measures power based on the current flowing at the consumer's power receiving point and the voltage applied to the power receiving point to obtain a power measurement value and transmits information on the power measurement value and a predetermined received power target value, a power control unit that receives the information from the power measurement unit and sequentially updates the charging power target value of the storage battery based on the received power measurement value and the received power target value, and an AC / DC conversion circuit that charges the storage battery in accordance with the control of the power control unit.

[0009] Furthermore, a method for charging a storage battery according to one embodiment of the present invention is a method for charging a storage battery in a case where a power storage system exists, which is composed of an electric vehicle equipped with a storage battery and a consumer, and comprises electrically connecting the consumer and the electric vehicle to each other using a charging cable, measuring a current flowing at a power receiving point of the consumer and power based on a voltage applied to the power receiving point to obtain a power measurement value, transmitting information on the power measurement value and a predetermined received power target value, sequentially updating a charging power target value of the storage battery based on the received power measurement value and the received power target value, and charging the storage battery according to the charging power target value. [Effects of the Invention]

[0010] According to the present invention, it is possible to prevent the received power from becoming excessive and causing the main breaker to trip, and to charge the storage battery with appropriate charging power by effectively utilizing available power. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a diagram showing an example of an outline of equipment on the consumer side (residential side) of the power storage system. [Figure 2] FIG. 2 is a diagram showing an example of an outline of equipment on the electric vehicle side of the electricity storage system. [Figure 3] FIG. 3 is a circuit diagram showing a commonly used AC / DC conversion circuit as a reference example. [Figure 4] FIG. 4 is a diagram showing an example of an AC voltage (dotted line) and a current (solid line) when leading-phase reactive power is injected into the AC / DC conversion circuit of FIG. [Figure 5] FIG. 5 is a circuit diagram showing the AC / DC conversion circuit of this embodiment. [Figure 6] FIG. 6 is a diagram showing an example of an AC voltage (dotted line) and a current (solid line) when leading-phase reactive power is injected into the AC / DC conversion circuit of FIG. DETAILED DESCRIPTION OF THE INVENTION

[0012] [Summary of the embodiment] The gist of the embodiments of the present invention includes at least the following.

[0013] (1) The present disclosure provides an energy storage system that electrically connects an electric vehicle equipped with a storage battery to a consumer via a charging cable, and includes a power measurement unit that measures the current flowing at the consumer's power receiving point and the power based on the voltage applied to the power receiving point to obtain a power measurement value and transmits information on the power measurement value and a predetermined received power target value; a power control unit that receives the information from the power measurement unit and sequentially updates the charging power target value of the storage battery based on the received power measurement value and the received power target value; and an AC / DC conversion circuit that charges the storage battery in accordance with the control of the power control unit.

[0014] In the energy storage system configured as described above, the power control unit successively updates the target charging power value of the storage battery based on the received measured power value and target receiving power value. Therefore, the target charging power value is not always constant but may change based on the current measured power value and target receiving power value. In this way, it is possible to prevent excessive received power from tripping the main breaker and to charge the storage battery with appropriate charging power by effectively utilizing available power.

[0015] (2) In the power storage system of (1), the target value of received power may be a fixed value or a variable value that changes depending on the time of year. If the target value is a variable value, for example, if the electricity rate varies depending on the time of day due to a contract with the power company, the electricity rate can be reduced by changing the target value for received power accordingly.

[0016] (3) In the power storage system of (1) or (2) above, the power control unit can set the charging power target value within a range from 0 to a charging power upper limit value. In this case, it is possible to prevent the storage battery from being discharged and overcharged.

[0017] (4) In any of the energy storage systems (1) to (3) above, it is preferable that the acquisition of the power measurement value, the transmission of the information, and the update of the charging power target value are performed at intervals equal to or less than the period of the AC fundamental wave at the power receiving point. In this case, the charging power can be reduced earlier than the main breaker trips in response to an overcurrent, thereby preventing tripping.

[0018] (5) In any one of the power storage systems (1) to (4) above, for example, the power measurement unit is installed in the consumer facility, and the power control unit and the AC / DC conversion circuit are mounted on the electric vehicle. In this case, the necessary information is provided by the consumer side, and the power control unit can charge the vehicle according to the provided information. Therefore, the electric vehicle can be charged by other equipment that is compatible with the same system as the consumer side, and even if the electric vehicle is replaced, it can be charged at the same consumer side.

[0019] (6) In any one of the power storage systems (1) to (5) above, the power measurement unit may have a display unit that displays the current power measurement value. In this case, for example, the measured power value and the target received power value can be displayed on the display unit to alert the residents of the consumer house. For example, if the residents look at the display unit and save power on non-essential loads, it becomes possible to obtain more charging power.

[0020] (7) In any of the energy storage systems (1) to (6) above, the AC / DC conversion circuit may be a full-bridge circuit configured with switching elements, and the power control unit may control the AC / DC conversion circuit so that a leading-phase reactive current flows from the consumer to the AC / DC conversion circuit. In this case, when the AC voltage of the consumer is reduced due to charging of the storage battery, the reduction in AC voltage can be suppressed.

[0021] (8) In any one of the power storage systems (1) to (7) above, for example, communication between the power measurement unit and the power control unit is performed via the charging cable. In this case, by attaching the charging cable to the electric vehicle, it is possible to connect the power line for charging and the communication line at the same time.

[0022] (9) In the power storage system of any one of (1) to (8) above, the power control unit may be configured to operate the AC / DC conversion circuit so as to discharge the storage battery. In this case, not only can the consumer provide charging power to the battery of the electric vehicle, but the battery can also supply power to the consumer. For example, if the battery is charged at a low cost at a location other than the consumer's, and then discharged back at the consumer's location, it can reduce electricity bills and mitigate the duck curve phenomenon.

[0023] (10) On the other hand, this is a method for charging a storage battery when there is a power storage system consisting of an electric vehicle equipped with a storage battery and a consumer, the method comprising: electrically connecting the consumer and the electric vehicle to each other using a charging cable; measuring the current flowing at the consumer's power receiving point and the power based on the voltage applied to the power receiving point to obtain a power measurement value; transmitting information on the power measurement value and a predetermined received power target value; sequentially updating the charging power target value of the storage battery based on the received power measurement value and the received power target value; and charging the storage battery according to the charging power target value.

[0024] According to the above-described battery charging method, the target charging power of the battery is updated sequentially based on the received measured power value and the target receiving power value. Therefore, the target charging power value is not always constant but may change based on the current measured power value and the target receiving power value. In this way, it is possible to prevent excessive received power from tripping the main breaker and to charge the battery with appropriate charging power by effectively utilizing available power.

[0025] [Details of the embodiment] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A power storage system and a method for charging a storage battery according to an embodiment of the present invention will be described below with reference to the drawings.

[0026] <<Example of a power storage system configuration>> 1 is a diagram showing an example of an overview of the equipment on the consumer side (residential side) of the energy storage system 100. For ease of explanation, the commercial power system 1 to the distribution board 6 are shown as double-line diagrams, but the rest are shown as single-line diagrams.

[0027] In Figure 1, a power meter 3 is connected to a single-phase three-wire service line 2 coming from a commercial power grid 1. The equipment from the commercial power grid 1 to the power meter 3 is owned by the electric power company. If the starting point on the consumer 4 side from the power meter 3 is the power receiving point 5, then the electrical wiring from the power receiving point 5 to the consumer 4 side is owned by the consumer 4. The power meter 3 has a bidirectional metering function for buying and selling electricity.

[0028] The power receiving point 5 and the distribution board 6 in the consumer 4 are connected to each other by two voltage lines, 7u and 7w, and a neutral line, 7o. The current detection units 8 are provided on the circuits 7u, 7o, and 7w. The current detection units 8 are, for example, composed of a current sensor (CT) 8u and a current sensor 8w, respectively, provided on the circuits 7u and 7w. The circuits 7u, 7o, and 7w drawn into the distribution board 6 branch off from the primary side of the main breaker and are drawn out as voltage measurement lines 9u, 9o, and 9w. The voltage measurement lines 9u, 9o, and 9w are input to a power measurement unit 12. The current detection unit 8 can detect the current flowing through the power receiving point 5. The detection output of the current detection unit 8 is sent to the power measurement unit 12. The power measurement unit 12 measures the power at the power receiving point 5 based on the detection output of the current detection unit 8 and the voltage directly received via the voltage measurement lines 9u, 9o, and 9w. The power measurement unit 12 includes a display unit 12d for displaying measurement data, etc. The display unit 12d may be a separate monitor that can communicate with the main body of the power measurement unit 12.

[0029] The consumer 4 is provided with, for example, a solar power generation panel 10. The power generation output of the solar power generation panel 10 is converted into AC power by a power conditioner 11. The AC power output from the power conditioner 11 is sent to a distribution board 6. Note that although the solar power generation panel 10 is a typical example of a distributed power source, other distributed power sources such as fuel cells may also be used.

[0030] Although not shown in the figure, the distribution board 6 is provided with a main breaker and a number of breakers under it, and indoor and outdoor wiring is laid out within the customer premises 4 via each breaker.

[0031] A charging stand 13 for charging electric vehicles is provided in the parking lot of this consumer 4. The charging stand 13 receives a voltage supply of, for example, 200 V via a power line 14p drawn from the distribution board 6. A charging cable 15 is provided at the end of the charging cable 15, which is provided with a connector 15c that can be attached to and detached from the electric vehicle.

[0032] The power measurement unit 12 measures the current flowing through the power receiving point 5 and the power based on the voltage applied to the power receiving point 5 to obtain a power measurement value. A predetermined target value for received power is set and stored in the power measurement unit 12. The power measurement unit 12 is connected to the charging stand 13 via a communication line 14c. The charging cable 15 is a single cable that combines the power line 14p and an extension of the communication line 14c. The power measurement unit 12 can send information on the measured power measurement value and the target value for received power to the electric vehicle 20 (Fig. 2) via the communication line 14c.

[0033] The power measurement unit 12 can be configured solely by hardware, but may also include a computer. In the case where a computer is included, the computer executes software (computer programs) to realize the necessary control functions. The software is stored in a storage device (not shown) of the power measurement unit 12.

[0034] FIG. 2 is a diagram showing an example of an overview of the equipment on the electric vehicle side of the power storage system 100. In the diagram, an electric vehicle 20 is equipped with a large-capacity storage battery 21 for driving. An AC / DC conversion circuit 22 capable of converting AC to DC and vice versa is connected to the storage battery 21. The AC / DC conversion circuit 22 is controlled by a power control unit 23. The power control unit 23 includes, for example, a computer, and the computer executes software (computer programs) to realize the necessary control functions. The software is stored in a storage device (not shown) of the power control unit 23.

[0035] When connector 15c of charging cable 15 is attached to electric vehicle 20, power line 24p connected to AC / DC conversion circuit 22 is connected to power line 14p on the consumer 4 side. In addition, communication line 24c connected to power control unit 23 is connected to communication line 14c on the consumer 4 side.

[0036] Charging power control In the above-described energy storage system 100, the current detection unit 8 is disposed closer to the grid than the position on the electrical path where the output of the solar power generation panel 10 enters the distribution board 6. Therefore, the power that can be consumed by the consumer 4, including the charging power for the electric vehicle 20, can be increased to the total value obtained by adding the upper limit of the power received from the commercial power grid 1 to the power generated by the solar power generation panel 10.

[0037] The power measurement unit 12 measures the power (effective power) p r Calculate the power p r The sign of is explained assuming that the direction of power reception from the commercial power system 1 is positive and the direction of reverse power flow is negative. Power measurement unit 12 obtains and updates the power measurement value at the fundamental wave period (50 or 60 Hz) of commercial power system 1. Power measurement unit 12 transmits the power measurement value obtained by measurement to power control unit 23.

[0038] The power control unit 23 calculates the power measurement value p r and the target power receiving value p * rand calculate the charging power target value p of the AC / DC conversion circuit 22 based on the following formula (1) or (2): * c Update K p is the proportional gain, K i is the integral gain. When using equation (1), the third term on the right hand side (integral term) may be omitted. Note that differences in character fonts in equations (1) and (2) below, as well as equations (3) and (4) described later, are meaningless. The same characters represent the same physical quantity regardless of the character font.

[0039] JPEG0007726334000001.jpg21165 ···(1)

[0040] JPEG0007726334000002.jpg22165 ···(2)

[0041] Target receiving power value p * r However, when power is supplied from the commercial power grid 1 under a time-of-day contract, p may be set to a fixed value in combination with time information during times when electricity rates are high. * r Set p to a small value and use it during times when electricity prices are low. * r By setting the value to a large value, it is possible to save on electricity charges for charging the electric vehicle 20.

[0042] The power control unit 23 updates the charging power target value p * c Furthermore, the charging power upper limit p c-max Compared with p by Eq. (3), * c [n+1] is rewritten. The power control unit 23 rewrites p * c If [n+1] is negative, it is treated as 0 and charging is stopped. * c [n+1] is p c-max If it is equal to or greater than p *c [n+1], p c-max Rewrite it as follows: Charging power upper limit p c-max may be the maximum allowable power value of the AC / DC conversion circuit 22, or may be an optimum value calculated from the state of charge of the storage battery 21, the target state of charge, and the time required for charging.

[0043] JPEG0007726334000003.jpg25165 ···(3)

[0044] Power measurement value p r If the power measurement value p transmitted from the power measurement unit 12 to the power control unit 23 exceeds the upper limit of the received power, the main breaker of the distribution board 6 will react and trip within a few seconds, for example, to cut off the current. Therefore, it is desirable that the power control unit 23 throttles the charging power and controls the received power to within the allowable range before the current is cut off. r It is desirable to update the value at a cycle equal to or shorter than the AC fundamental wave cycle.

[0045] As shown in Fig. 2, the power control unit 23 and the AC / DC conversion circuit 22 may be configured to be mounted on the electric vehicle 20, or may be configured to be incorporated into, for example, the charging station 13. In the former case, the necessary information is provided from the consumer 4, and the power control unit 23 can charge the electric vehicle 20 according to the provided information. Therefore, the electric vehicle 20 can be charged by other equipment compatible with the same system as the consumer 4, and even if the electric vehicle 20 is replaced, it can be charged at the same consumer 4.

[0046] Also, for example, the display unit 12d of the power measurement unit 12 displays the power measurement value p r The current value of and the target value of received power p * r By displaying this, it is possible to alert the residents of the consumer premises 4. For example, if the residents look at the display on the display unit 12d and save power on non-essential loads, more charging power can be obtained and quick charging can be performed.

[0047] Summary so far The disclosed system is an energy storage system 100 that electrically connects an electric vehicle 20 equipped with a storage battery 21 to a consumer 4 via a charging cable 15, and measures the current flowing through a power receiving point 5 of the consumer 4 and the power based on the voltage applied to the power receiving point to generate a power measurement value p r The power measurement value and the predetermined receiving power target value p * r and a power measurement unit 12 that receives information from the power measurement unit 12 and calculates a charging power target value p of the storage battery 21 based on the received power measurement value and the receiving power target value. * c and an AC / DC conversion circuit 22 that charges the storage battery 21 in accordance with the control of the power control unit 23.

[0048] In the power storage system 100 configured as described above, the power control unit 23 receives the power measurement value p r and the target receiving power value p * r Based on this, the charging power target value p * c Therefore, the charging power target value p * c is not always constant, and the current power measurement value p r and the target receiving power value p * r In this way, it is possible to prevent the received power from becoming excessive and tripping the main breaker, and to charge the storage battery 21 with appropriate charging power by effectively utilizing available power.

[0049] Also disclosed is a method for charging a storage battery in a case where there is an electric vehicle equipped with the storage battery 21 and a consumer 4, (a) A consumer 4 and an electric vehicle 20 are electrically connected to each other using a charging cable 15; (b) The power based on the current flowing through the power receiving point 5 of the consumer 4 and the voltage applied to the power receiving point 5 is measured to obtain the power measurement value p r and the power measurement value pr and a predetermined receiving power target value p * r Disseminate information on (c) Received power measurement value p r and the target receiving power value p * r Based on this, the charging power target value p * c Sequentially update the (d) Charging power target value p * c This is a method for charging a storage battery, in which the storage battery 21 is charged according to the

[0050] According to the above-described battery charging method, the target charging power of the battery is updated sequentially based on the received measured power value and the target receiving power value. Therefore, the target charging power value is not always constant but may change based on the current measured power value and the target receiving power value. In this way, it is possible to prevent excessive received power from tripping the main breaker and to charge the battery with appropriate charging power by effectively utilizing available power.

[0051] <<Mitigating grid voltage drops caused by concentrated load consumption>> In a neighborhood, if load consumption in each house and charging of electric vehicles are concentrated, the voltage of the power distribution system will drop. In this case, the power control unit 23 c-max Voltage drops can be alleviated by reducing the set value of and suppressing the charging power. In order to suppress voltage drops while maintaining the charging power, the charging current (positive when flowing from the commercial power grid 1 to the consumer 4) can be made to advance with respect to the grid voltage, and leading reactive power can be injected. Leading reactive power increases the grid voltage, so voltage drops can be alleviated.

[0052] A suitable example of an AC / DC conversion circuit in this case will be described. 3 is a circuit diagram showing, as a reference example, a commonly used AC / DC conversion circuit 220. In the figure, the AC / DC conversion circuit 220 is located between a commercial power system 1 and a storage battery 21. The AC / DC conversion circuit 220 includes a diode bridge 227, a power factor correction (PFC) circuit 228, and a DC / DC converter 229.

[0053] Fig. 4 is a diagram showing an example of AC voltage (dotted line) and current (solid line) when leading-phase reactive power is injected into AC / DC conversion circuit 220 of Fig. 3. When reactive power is injected into AC / DC conversion circuit 220 shown in Fig. 3, distortion occurs near the zero crossing of the current as shown in Fig. 4.

[0054] 5 is a circuit diagram showing an AC / DC conversion circuit 22 of this embodiment. In the figure, the AC / DC conversion circuit 22 is located between the commercial power system 1 and the storage battery 21. The AC / DC conversion circuit 22 includes a filter circuit 221, a full-bridge circuit 222 configured with gate-controllable switching elements, a smoothing capacitor Cd, and a DC / DC converter 223. The filter circuit 221 includes a capacitor Ca and an AC reactor L. The full-bridge circuit 222 includes switching elements S1, S2, S3, and S4, which are, for example, IGBTs (Insulated Gate Bipolar Transistors). The switching elements S1 to S4 and the DC / DC converter 223 are controlled by the power control unit 23.

[0055] Fig. 6 is a diagram showing an example of AC voltage (dotted line) and current (solid line) when leading-phase reactive power is injected into the AC / DC conversion circuit 220 of Fig. 5. When reactive power is injected in the AC / DC conversion circuit 22 shown in Fig. 5, as shown in Fig. 6, a distortion-free sinusoidal current can be maintained even when reactive power is injected.

[0056] 《Power peak shift and voltage drop mitigation through discharge from electric vehicles》 5 is used instead of the AC / DC conversion circuit 22 in FIG. 2, the energy charged in the storage battery 21 mounted on the electric vehicle 20 can be used for load consumption on the side of the consumer 4. In this case, the charging power target value p * c [n+1] is reset to the following equation (4) instead of equation (3). As a result, the charging current target value p * c [n+1] is the lower limit of discharge power p c-min (negative value, maximum discharge power) * r If is set to a smaller value greater than or equal to 0, the amount of discharge from the electric vehicle can be increased while preventing reverse power flow from the consumer to the grid.

[0057] JPEG0007726334000004.jpg26165 ···(4)

[0058] If the electric vehicle discharges electricity when the grid voltage measured by the power measurement unit 12 is low, the drop in grid voltage can be alleviated. According to this circuit and control, electric vehicle 20 can be charged with power during times when surplus power is generated by a distributed power source or the like installed in consumer 4, and can be discharged and used for load consumption during times when there is a power shortage. Furthermore, as described above, when electric vehicle 20 is equipped with power control unit 23 and AC / DC conversion circuit 22, electric vehicle 20 can be discharged at a location different from where it is charged. For example, if electric vehicle 20 is used for commuting to work, surplus power from a solar power generation system installed at the workplace can be absorbed during the day and used in conjunction with the power peak after returning home, thereby contributing to the stabilization of the entire power system.

[0059] "others" In the above embodiment, the power storage system 100 is described as including the electric vehicle 20, but the power storage system can also be configured in a similar manner for other electric vehicles such as electric motorcycles and electric industrial vehicles. In the above embodiment, the communication from the power measurement unit 12 to the power control unit 23 is wired communication, but may be replaced by wireless communication.

[0060] 《Addendum》 The present invention is intended to cover a wide range of applications, including those related to the present invention, including those related to the present invention. [Explanation of symbols]

[0061] 1 Commercial power system 2. Service line 3. Power meter 4 Consumer 5. Power receiving point 6 Distribution board 7u,7o,7w electric line 8 Current detection section 8u Current Sensor 8w current sensor 9u Voltmeter side wire 9o Voltage measurement wire 9w voltage measurement wire 10. Solar panels 11 Power conditioner 12 Power measurement section 12d Display section 13 Charging Station 14p power line 14c communication line 15 Charging cable 15c connector 20. Electric Vehicles 21 Storage battery 22 AC / DC conversion circuit 23 Power Control Unit 24p power line 24c communication line 100 Energy Storage System 220 AC / DC conversion circuit 221 Filter Circuit 222 Full-bridge circuit 223 DC / DC converter 227 Diode Bridge 228 Power Factor Correction Circuit 229 DC / DC Converter Ca capacitor Cd smoothing capacitor L AC reactor S1, S2, S3, S4 switching elements

Claims

1. A charging system that electrically connects an electric vehicle equipped with a storage battery to a consumer via a charging cable and charges the storage battery, A charging system that acquires a power measurement value and a predetermined received power target value obtained by measuring the current flowing at the consumer's power receiving point and the power based on the voltage applied to the power receiving point, and sequentially updates the charging power target value of the storage battery based on the acquired power measurement value and the received power target value.

2. 2. The charging system according to claim 1, wherein the charging power target value is a fixed value or a variable value that changes depending on the time of year.

3. 3. The charging system according to claim 1, wherein the target charging power value is set within a range from 0 to an upper limit of charging power.

4. a power control device that controls an AC / DC conversion circuit that charges the storage battery based on the charging power target value; the AC / DC conversion circuit is a full-bridge circuit configured with switching elements, The charging system according to claim 1 , wherein the power control device controls the AC / DC conversion circuit so that a leading-phase reactive current flows from the consumer to the AC / DC conversion circuit.

5. a power control device that controls an AC / DC conversion circuit that charges the storage battery based on the charging power target value; The charging system according to claim 1 , wherein the power control device is capable of operating the AC / DC conversion circuit so as to discharge the storage battery.

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