JP2013138535A - Charge control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust charging current to an appropriate value while avoiding a trip of a breaker.SOLUTION: If a control unit 20 of a power monitoring device 2 periodically transmits an adjustment command to a charge controller 1 at a shorter cycle than a tripping operation time, charging current can be adjusted to an appropriate value while avoiding the trip of a trunk breaker 40 and a limiter. In addition, in a period from a time point when an entire consumption current passed a regulation value to a time when the tripping operation time passes, the adjustment command to lower the upper limit value of the charging current will be transmitted a plurality of times from the power monitoring device 2. Therefore, a possibility that a communication control unit 14 of the charge controller 1 will fail to receive the adjustment command due to an impact of noise will reduce and the trip of the trunk breaker 40 and the limiter can be surely avoided.

Description

  The present invention relates to a charging control system that controls charging of an electric vehicle such as an electric vehicle.

  As a conventional example, for example, there is a charge control system described in Patent Document 1. This charging control system includes a plurality of charging devices. Each charging device is for charging a battery-type forklift, and has a power cord connected to a power outlet connected to a facility power source in the factory via a breaker. In addition, the charging device is equipped with a communication function, and transmits / receives information regarding the charging state to / from other charging devices connected to the facility power supply via a communication line.

  In this conventional example, the total current limit value, which is a current value that can be used by the entire charging device connected to the facility power supply, is set to an arbitrary current value, and the current used in each charging device is based on this value. The charging device is automatically set after confirming the charging status of other charging devices. For this reason, the power consumed by the charging device when charging the electric vehicle (battery-type forklift) is appropriately set without considering the power capacity of the facility power source that supplies power to the charging device. Therefore, the user can charge the electric vehicle satisfactorily without increasing the power capacity of the equipment power source and without worrying about the amount of current in use with the charging device connected to the power source. Become.

JP 2003-333706 A

  By the way, when the overload current (<short circuit current) flows, the breaker normally does not trip immediately (tripping operation), but the overload current continues to flow for a predetermined time (tripping operation time) or longer. Is configured to trip. Therefore, as in the conventional example described in Patent Document 1, it is not an indispensable condition for preventing the breaker from tripping, so that the total current value does not always exceed the limit value.

  In other words, if it is less than the trip operation time, the breaker will not trip even if overload current flows, so if the charge current is reduced from the time when the overload current flows until the trip operation time elapses, the breaker trips Can be avoided.

  The present invention has been made in view of the above problems, and an object thereof is to adjust a charging current to an appropriate value while avoiding a trip of a breaker.

  A charge control system of the present invention is inserted between a breaker and an electric vehicle, and monitors a current flowing through the breaker, a charge control device that instructs an upper limit value of a charge current to the electric vehicle, and the current is A power monitoring device that causes the charge control device to adjust the upper limit value so as not to exceed a rated current of the breaker, and the power monitoring device sends a command for adjusting the upper limit value to the breaker. Is periodically transmitted to the charging control device at a cycle shorter than the tripping operation time.

  The charging control system of the present invention has an effect that the charging current can be adjusted to an appropriate value while avoiding the trip of the breaker.

It is a system configuration figure showing an embodiment of a charge control system concerning the present invention. It is a time chart for demonstrating the basic charge control operation | movement of the charge control apparatus same as the above.

  Hereinafter, referring to the drawings, an embodiment in which the technical idea of the present invention is applied to a charge control device and a charge control system that are installed in a detached house and control charging of an electric vehicle using electric power supplied from an electric power system. And will be described in detail. However, the electric vehicle subject to charge control is not limited to an electric vehicle, and may be an electric vehicle other than an electric vehicle, for example, a battery-type forklift described in the related art.

  As shown in FIG. 1, single-phase, three-wire AC power is supplied from a power system 100 to a house through a residential distribution board (housing board) 4. The housing board 4 has a main breaker 40 whose primary side is connected to the power system 100, and a plurality of branch breakers 41 branched and connected to the secondary side of the main breaker 40. However, a limiter (also called a current limiter or a contract breaker) may be inserted on the primary side of the main breaker 40. In addition, although illustration is abbreviate | omitted, an outlet and load (a lighting fixture, an electromagnetic cooker, etc.) are connected to the secondary side of each branch breaker 41 via indoor wiring.

  The charge control device 1 of this embodiment constitutes a charge control system together with the power monitoring device 2 and the notification device 3 as shown in FIG.

  The power monitoring device 2 includes a control unit 20, a current measurement unit 21, a signal transmission unit 22, a communication unit 23, and the like. The current measuring unit 21 measures the currents flowing in the two power lines other than the neutral line among the three power lines connected to the primary side of the main breaker 40 using current sensors 210 and 211, respectively. Each measurement value is output to the control unit 20. The control unit 20 has a microcomputer as a main component, and is based on the current value measured by the current measurement unit 21 and the measured value (voltage value) of the primary side voltage (input voltage) of the main breaker 40. The instantaneous value or integrated value of the power supplied from (the supplied power) is calculated. The signal transmission unit 22 performs signal transmission with the notification device 3. The communication unit 23 performs communication with the charging control apparatus 1 via the communication line 24, and performs serial communication based on the RS485 standard, for example. However, the communication method of the communication unit 23 is not limited to the RS485 standard.

  The charging control device 1 includes a signal processing unit 10, a zero-phase current transformer 11, a leakage detection unit 12, an opening / closing unit 13, a communication control unit 14, a charging cable 15, a charging connector 16, a current control unit 17, and the like. The charging control device 1 is installed near a parking space (garage) of the electric vehicle 200 and is one of the branch circuits branched by the branch breaker 41 of the housing board 4 (the branch breaker 41 at the lower right end in FIG. 1). Connected to. The charging cable 15 is formed by covering a power supply line 150 through which a supply current (charging current) to the electric vehicle 200 flows and a transmission line 151 through which a pilot signal, which will be described later, is transmitted, with an insulating sheath, and a charging connector 16 at the tip portion. Is provided. The charging connector 16 is inserted and connected so as to be freely inserted into and removed from an insertion port (inlet) provided in the vehicle body of the electric vehicle 200. When the charging connector 16 is plugged into the insertion port, power (charging power) is supplied from the power system 100 via the housing panel 4 and the charging control device 1, and the signal processing unit 10 of the charging control device 1. And a pilot signal can be transmitted between the electric vehicle 200 and a charging ECU (electronic control unit).

  The open / close unit 13 has an electromagnetic relay (not shown) inserted into the power supply path from the branch breaker 41 to the power supply line 150, and turns on / off the electromagnetic relay according to an instruction from the current control unit 17. Open and close the feeding path. The leakage detector 12 detects the unbalanced current flowing in the power supply path with the zero-phase current transformer 11, and determines that a leakage has occurred when the detected level of the unbalanced current exceeds the threshold value. The unit 13 is controlled to open the power supply path. The communication control unit 14 performs communication (RS485 standard serial communication) with the communication unit 23 of the power monitoring device 2. As will be described later, the current control unit 17 adjusts the charging current supplied to the electric vehicle 200 according to the charging control information sent from the power monitoring device 2. The signal processing unit 10 transmits a pilot signal via the transmission line 151. In the power monitoring device 2, the current (charge current) supplied to the electric vehicle 200 via the charge control device 1 is measured by the current sensor 212.

  The notification device 3 includes a control unit 30, a signal transmission unit 31, a display unit 32, an acoustic unit 33, an operation input unit 34, and the like. The signal transmission unit 31 performs signal transmission with the signal transmission unit 22 of the power monitoring device 2. The display unit 32 includes a display element formed of a light emitting diode and a light emitting circuit that is controlled by the control unit 30 to cause the display element to emit light. However, a two-dimensional display device such as a liquid crystal display or an organic EL display may be used instead of the light emitting diode. The acoustic unit 33 includes a speaker and a drive circuit that drives the speaker. The operation input unit 34 includes a push button switch, and outputs an operation signal when the push button switch is pressed.

  The control unit 30 includes a microcomputer as a main component, and notifies the user (resident) of monitoring information received from the power monitoring device 2 via the signal transmission unit 31 by controlling the display unit 32 and the sound unit 33. have. The control unit 30 also has a control function of transmitting a control command corresponding to the operation signal output from the operation input unit 34 to the power monitoring device 2 via the signal transmission unit 31.

  Here, the basic charge control operation of the charge control device 1 will be described with reference to the time chart of FIG. First, when the charging connector 16 is connected to the insertion port of the electric vehicle 200 at time t0, a predetermined voltage V1 (for example, V1 = 12 volts) is applied from the signal processing unit 10 to the transmission line 151. The voltage applied to the transmission line 151 serves as a transmission medium for a control pilot (CPLT) signal (hereinafter abbreviated as a pilot signal). Depending on the voltage level and the duty ratio, the charging ECU and the signal will be described later. Various information is exchanged with the processing unit 10.

  When the charging ECU detects the pilot signal of voltage V1, it lowers the voltage level of the pilot signal from V1 to V2 (for example, V2 = 9 volts) (time t1 to t2). When the signal processing unit 10 detects that the pilot signal has decreased from V1 to V2, the signal processing unit 10 outputs a pulsed pilot signal having a predetermined frequency (for example, 1 kilohertz) (from time t2). The signal level of the pilot signal is ± V1, but the upper limit level is stepped down to V2. The duty ratio of the pilot signal indicates an upper limit value of the charging current (current capacity of the charging control device 1), and is set in advance for each charging control device 1. For example, when the current capacity is 12 amperes, the duty ratio is set to 20%, and when the current capacity is 30 amperes, the duty ratio is set to 50%. When the charging ECU detects the duty ratio of the pilot signal and recognizes the current capacity, it lowers the voltage level of the pilot signal from V2 to V3 (for example, 6V) (time t3). The signal processing unit 10 detects that the signal level of the pilot signal has decreased from V2 to V3, and notifies the current control unit 17 of it. The notified current control unit 17 closes the opening / closing unit 13 and starts supplying charging power.

  The charging ECU sets the current value (≦ current capacity) for charging the storage battery to the target level based on the current capacity, and commands the charger (not shown) installed in the electric vehicle 200 to charge Is output. The charger that has received the charging command charges the storage battery while adjusting the charging current so as not to exceed the current value set by the charging ECU (from time t3). When the charge level of the storage battery reaches the target level, the charging ECU outputs a charge end command to the charger to finish charging the storage battery, and returns the voltage level of the pilot signal from V3 to V2 (time t4) . When the charger receives the charging end command, the charger ends the charging of the storage battery.

  The signal processing unit 10 detects that the pilot signal has changed from V3 to V2, and notifies the current control unit 17 of the change. The notified current control unit 17 opens the opening / closing unit 13 and stops the supply of AC power. The charging ECU restores the voltage level of the pilot signal to the original V1 (time t5). When the voltage level of the pilot signal returns to V1, the signal processing unit 10 stops oscillation at a predetermined frequency, maintains the voltage level of the pilot signal at V1, and returns to the standby state (time t6).

  As described above, the charging control device 1 is mounted on the electric vehicle 200 by turning on / off the supply of charging power to the electric vehicle 200 and instructing the charging ECU of the electric vehicle 200 to the upper limit value of the charging current. It controls the charging of the storage battery.

  By the way, charging of the electric vehicle 200 usually requires a large charging current of about several tens of amperes to several tens of amperes. On the other hand, in a normal house, the rated current of the main breaker 40 (limiter and main breaker 40 when the limiter is installed) is set to about 30 amperes to 60 amperes. Therefore, when the electric vehicle 200 is charged when a load device with large current consumption such as an electromagnetic cooker or an air conditioner is used, the charging current flows up to an upper limit value set in advance in the charge control device 1. Then, the main breaker 40 and the limiter may trip.

  Therefore, when the current flowing through the main breaker 40 (total current consumption) exceeds the regulation value, the control unit 20 of the power monitoring device 2 sets the upper limit value of the charging current from the current charging current value to the total current consumption. A command (adjustment command) for current value obtained by subtracting the difference between the values is transmitted from the communication unit 22. The total consumption current is the sum of the charging current and the consumption current of the load device (load consumption current). Further, the regulation value is set to, for example, a value of 80% of the rated current of the main breaker 40 or 90% of the rated current of the limiter.

  In the charging control device 1, the adjustment command transmitted from the power monitoring device 2 is received by the communication control unit 14 and passed to the current control unit 17. The current control unit 17 instructs the signal processing unit 10 to set the upper limit value of the charging current to be equal to or less than the upper limit value specified by the adjustment command. When the signal processing unit 10 receives an instruction from the current control unit 17, it reduces the on-duty ratio of the pilot signal. For example, when the current capacity of the charging cable 15 is 20 amperes, the on-duty ratio, which was 50% at the beginning, is reduced to 40% to 20%, and as a result, the upper limit value of the charging current is lower than the original 20 amperes. Will be adjusted to a value (eg, 10 amps).

  The charging ECU of the electric vehicle 200 sets the current value of the charging current again based on the adjusted upper limit value and outputs a charging command to the charger. The charger that has received the charging command charges the storage battery while adjusting the charging current so as not to exceed the new current value set by the charging ECU. As a result, since the charging current supplied to the electric vehicle 200 decreases, it can be avoided that the total current consumption exceeds the rated current of the main breaker 40.

  By the way, the above-described adjustment of the upper limit value needs to be performed within a time shorter than the tripping operation time of the main breaker 40 (or limiter). The tripping time of the main breaker and limiter is considered to be set to approximately 4 seconds or less according to the investigation by the present inventors. Therefore, if the upper limit value of the charging current is adjusted to be smaller in less than 4 seconds after the total current consumption exceeds the regulation value, the trip (tripping) of the main breaker 40 and limiter should be avoided. Can do.

  Therefore, the control unit 20 of the power monitoring device 2 periodically adjusts the charging control device 1 from the communication unit 23 with a cycle shorter than the tripping operation time of the main breaker 40 (or limiter) (for example, 1 second cycle). Preferably, the command is transmitted. The current measuring unit 21 measures a current value at a cycle (sampling cycle) of less than 1 second and outputs it to the control unit 20. The control unit 20 calculates the total consumption current from the measurement value of the current measurement unit 21, compares the total consumption current with the limit value, determines the upper limit value of the charging current, and sends an adjustment command including the determined upper limit value to the communication unit Send from 23. However, while the total current consumption does not exceed the limit value, the same upper limit value is set, and when the total current consumption exceeds the limit value, the upper limit value is adjusted to a value smaller than the previous value.

  As described above, if the control unit 20 of the power monitoring device 2 periodically sends an adjustment command to the charging control device 1 at a cycle shorter than the tripping operation time, the charging current is avoided while avoiding tripping of the main breaker 40 and the limiter. Can be adjusted to an appropriate value. In addition, an adjustment command for lowering the upper limit value of the charging current is transmitted from the power monitoring device 2 a plurality of times during the period from when the total consumption current exceeds the regulation value until the tripping operation time elapses. Therefore, the possibility that the communication control unit 14 of the charging control device 1 fails to receive the adjustment command due to the influence of noise is reduced, and tripping of the main breaker 40 and the limiter can be reliably avoided.

1 Charging control device 2 Power monitoring device
40 Main breaker
200 Electric vehicle (electric vehicle)

Claims (1)

  A charge control device that is inserted between the breaker and the electric vehicle and instructs the electric vehicle to specify an upper limit value of the charging current; and the current flowing through the breaker is monitored, and the current does not exceed the rated current of the breaker In this way, the charging control device adjusts the upper limit value, and the power monitoring device has a command for adjusting the upper limit value shorter than the tripping time of the breaker. A charge control system characterized by periodically transmitting to the charge control device in a cycle.

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