KR20210051232A - Adaptive Charging Control Apparatus and Method through Automatic DC/AC Recognition of Electric Vehicles - Google Patents

Abstract

The present invention relates to an adaptive charging control apparatus through automatic recognition of direct current/alternating current of an electric vehicle and a method thereof, which realize a motor driving circuit and a storage battery charger necessarily provided in an electric vehicle in a single power circuit, and automatically recognize the type (for example, direct current and alternating current) of an input voltage of a charging terminal to control motor driving and charging by a single power circuit to optimally charge a battery. In a charging mode, a charging terminal input voltage is inspected by a controller to determine the type of the input voltage. If the determined type of the input voltage is direct current, charging of a battery is controlled based on a battery state and current control. If the determined type of the input voltage is alternating current, charging of the battery is controlled based on the battery state and power factor control.

Description

Adaptive Charging Control Apparatus and Method through Automatic DC/AC Recognition of Electric Vehicles}

The present invention relates to an adaptive charging control device and method through automatic DC/AC automatic recognition of an electric vehicle, and in particular, a motor driving circuit and a storage battery charger essential for an electric vehicle are implemented as a single power circuit, and a charging terminal terminal By automatically recognizing the type of input voltage (for example, DC, AC) and controlling the driving and charging of the electric motor with a single power circuit, it is possible to optimally charge the battery. It relates to an adaptive charging control device and method.

In general, an electric vehicle having a charging system is provided with a separate charger (On-Board Battery Charger) separate from the electric motor driver. This charger is used only to charge external electricity to the battery, and is used when the vehicle is in a charging station or parked.

1 is a block diagram of a general electric vehicle having a charging system.

The battery pack is configured in a form with a rated voltage of as high as possible, and it is configured in a form in which it is easy to obtain strong driving power by passing sufficient current to the electric motor. The On Board Charger receives AC, DC, or sends an optimal current to the capacitor suitable for the state of the battery, such as temperature or charging.

There is a drive circuit (Traction Drive) that controls the power of the motor, and it is used to accelerate by inputting power to the motor. This driving circuit is in charge of acceleration, and the deceleration is divided into a circuit type implemented by another converter and a type in which one circuit is in charge of two tasks.

In the current plug-in electric vehicle, deceleration is a process of converting the kinetic energy of an electric motor into electric energy and sending it to the battery. The technology is difficult to handle, so there is a method of sending the braking force to the battery with a separate generator. This is a technology to eliminate the inconvenience caused by Jerk, which is caused by discontinuity of electric power of the motor in a specific section when stopping during acceleration or deceleration or deceleration. For this reason, most electric vehicles currently have many vehicles composed of separate chargers, controllers, electric motors, generators, and batteries (see Korean Patent Laid-Open No. 10-2014-0137182).

As described above, in a general electric vehicle, the motor driver circuit and the battery charger circuit are configured as separate circuit systems and operated.

Since such a system is implemented with a plurality of power circuits, the number of parts of the system increases with an increase in weight, resulting in an increase in failure factors.

Meanwhile, in the general electric vehicle system as shown in FIG. 1, while charging the storage battery, a fixed power line is connected to charge the storage battery of the electric vehicle, and the electric motor does not operate. At this time, the motor drive circuit (motor driver) that drives the motor does not operate. Conversely, when the electric vehicle moves, the vehicle moves after removing the connection between the power line and the charger. In this case, the charger does not operate at all.

In other words, in most electric vehicles currently in operation, there is no case in which two circuits of a charger and a motor driver operate at the same time. This can be a wasteful element of the circuit or a failure element.

In addition, a general plug-in or hybrid electric vehicle system recognizes whether the charging voltage is AC or DC, and it is impossible to charge the optimal battery by controlling the power circuit accordingly. It is a technology that simply charges the battery for AC input. There is a limit.

Republic of Korea Patent Publication 10-2014-0137182 (published on 12.02.2014) (plug-in hybrid vehicle driving device and its control method)

Accordingly, the present invention has been proposed to solve the problems occurring in the general plug-in or hybrid electric vehicle and the prior art as described above, and implements a motor driving circuit and a storage battery charger, which are essentially provided in an electric vehicle, as a single power circuit. , DC/AC of an electric vehicle that automatically recognizes the type of input voltage (e.g., DC, AC) of the charging terminal terminal and controls the driving and charging of the motor with a single power circuit to optimally charge the battery. An object thereof is to provide an adaptive charging control device and method through automatic recognition.

In order to achieve the above object, the "adaptive charging control device through automatic DC/AC automatic recognition of an electric vehicle" according to the present invention is input by checking the charging terminal input voltage when the operation mode of the electric vehicle is the charging mode. A controller determining a type of voltage and outputting a power switching control signal according to the determined type of input voltage to control charging; According to the power switching control signal output from the controller, in the motor driving mode, the motor is driven with the discharged power of the battery, the energy of the motor is recovered and charged to the battery when decelerated, and the charging power supplied from the charger is input in the charging mode. An integrated power control unit for charging the battery by adjusting according to the voltage type and the battery state; And a power switch unit interposed between the integrated power control unit and the electric motor and the charger to selectively connect the integrated power control unit to the electric motor and the charger according to a power switching control signal of the controller.

The power switching control signal is characterized in that it includes a PWM power control signal for controlling the integrated power control unit in the charging mode and a power switch control signal for controlling the switching of the power switch unit.

In order to achieve the above object, the "adaptive charging control method through automatic DC/AC automatic recognition of an electric vehicle" according to the present invention includes (a) the input voltage by checking the input voltage of the charging terminal in the charging mode in the controller. Determining the type of; (b) controlling charging of the battery based on current control and battery state if the input voltage type is DC as a result of the determination in step (a); (c) if the type of the input voltage is alternating current as a result of the determination in step (a), controlling the charging of the battery based on power factor control and the battery state.

In the above, step (c) is characterized in that the frequency and phase of the AC current are controlled through PWM control of the integrated power controller to control the power power factor of the AC input terminal close to 1.

In the above, the battery state may include at least one of temperature, current, voltage, and voltage information between battery cells.

According to the present invention, motor driving, dynamic brake control, and charger operation can be performed using a single power circuit, thereby simplifying the configuration of the entire electric vehicle system, and minimizing failure factors by reducing the number of system components. There is an effect that can be.

In particular, since a single power circuit can drive an electric motor, drive a generator, and perform the role of a charger, it is possible to reduce the cost of implementing the entire system and improve the efficiency of the entire system.

In addition, according to the present invention, there is an effect of automatically recognizing the type (AC, DC) of the input voltage of the charging terminal and reducing the load on the power line or optimally charging the battery through current control according to the type of the input voltage. .

1 is a system configuration diagram of a typical plug-in electric vehicle,
2 is a circuit diagram of an adaptive charging control device through automatic DC/AC automatic recognition of an electric vehicle according to the present invention;
3 is an exemplary view of charging current and voltage during charging in the present invention,
Figure 4 is an exemplary implementation of a current sensor and a voltage detector in the present invention,
5 is a flowchart showing an adaptive charging control method through automatic DC/AC recognition of an electric vehicle according to the present invention.

Hereinafter, an adaptive charging control apparatus and method through automatic DC/AC automatic recognition of an electric vehicle according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

The terms or words used in the present invention described below should not be construed as being limited to a conventional or dictionary meaning, and the inventor should appropriately define the concept of terms in order to describe his own invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that it can be.

Therefore, the embodiments described in the present specification and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all the technical ideas of the present invention, and various equivalents and equivalents that can replace them at the time of the present application It should be understood that there may be variations.

2 is a circuit diagram of an adaptive charging control device through automatic DC/AC automatic recognition of an electric vehicle according to a preferred embodiment of the present invention, a controller 10, an integrated power control unit 20, a battery 30, and an electric motor 40. ), a charger 50 and a power switch unit 60 may be included.

When the operation mode of the electric vehicle is the charging mode, the controller 10 determines the type of the input voltage by examining the charging terminal input voltage, and controls charging by outputting a power switching control signal according to the determined type of input voltage. . Here, the type of input voltage means direct current or alternating current. This controller 10 controls the driving of the electric motor, the dynamic brake, and the charging operation as a whole. The controller 10 may use a digital controller such as a microprocessor in which firmware is mounted. Here, the power switching control signal may include a PWM power control signal for controlling the integrated power control unit 20 in a charging mode and a power switch control signal for controlling switching of the power switch of the power switch unit 60. .

Here, if the operation mode of the electric vehicle is the charging mode, the controller 10 automatically recognizes whether the input voltage is AC or DC by checking the input voltage of the charging terminal, and uses the power switching control signal according to the type of the automatically recognized input voltage. By controlling the integrated power control unit 20 that drives the electric motor 40 and charges the battery 30, the battery 30 is charged according to the input voltage type and the state of the battery 30, and is dedicated only to the charger. It can also be used.

In accordance with the power switching control signal output from the controller 10, the integrated power control unit 20 drives the motor 40 with the discharge power of the battery 2 in the motor driving mode, and reduces the energy of the motor 40 when deceleration. It collects and charges the battery 30, and in the charging mode, the charging power supplied from the charger 50 is adjusted according to the input voltage type and the state of the battery to charge the battery 30. The integrated power control unit 20 may control the flow of power by selectively connecting the battery 30, the electric motor 40, and the charger 50 using a single power circuit. The integrated power control unit 20 performs high-speed switching according to the PWM power control signal generated by the controller 10 to output the voltage of three phases (U, V, W) to the motor 40 or to control charging power. The unit 20 includes inductors 22 to 24 connected in series to each of the three phases to attenuate current smoothing and electromagnetic interference (EMI).

The power switch unit 60 is interposed between the integrated power control unit 20 and the electric motor 40 and the charger 50, and according to the power switching control signal of the controller 10, the integrated power control unit 20 ) Is selectively connected to the electric motor 40 and the charger 50. This power switch unit 60 connects the integrated power control unit 20 and the electric motor 40 in an electric motor mode according to a power switch control signal output from the controller 10, and in the charging mode, the integrated power control unit ( 20) and the charger 50 are connected.

5 is a flowchart showing an adaptive charging control method through automatic DC/AC automatic recognition of an electric vehicle according to the present invention, and shows a process implemented in software in the charging control device as shown in FIG. 2.

The adaptive charging control method through automatic DC/AC automatic recognition of an electric vehicle according to the present invention includes the steps of (a) determining the type of the input voltage by examining the input voltage of the charging terminal in the charging mode in the controller 10 (S101~ S102, S107), (b) if the input voltage type is DC as a result of the determination in step (a), controlling the charging of the battery based on current control and battery state (S103 to S106), (c) the (a) As a result of the determination in step ), if the type of the input voltage is AC, controlling the charging of the battery based on the power factor control and the battery state (S108 to S112).

In the step (c), it is preferable to control the AC frequency and phase through the PWM control of the integrated power control unit 20 to control the power power factor of the AC input terminal close to 1.

The battery state may include at least one of temperature, current, voltage, and voltage information between battery cells.

The adaptive charging control apparatus and method through automatic DC/AC automatic recognition of an electric vehicle according to the present invention configured as described above will be described in detail as follows.

In the plug-in electric vehicle, the charger operation and the motor driving operation are mutually exclusive, so the controller 10 checks the electric vehicle operation mode, and the integrated power control unit 20, which is a single power circuit, is appropriate according to the motor mode and the charging mode. With one power circuit, it performs three functions: the acceleration function in the motor mode, the dynamic brake function during deceleration, and the charging function in the charging mode. Of course, it also performs the functions of suspending and stopping the entire system.

First, when operating in the motor mode, the controller 10 controls the integrated power control unit 20 and the power switch unit 60 by outputting a power switch control signal and a PWM power control signal as a power switching control signal. According to the control, the power switches 61 to 63 for each phase of the power switch unit 60 perform a switching operation to interconnect the electric motor 40 and the integrated power control unit 20. Here, the power switches 61 to 63 for each phase operate identically and simultaneously. That is, the contact a and the contact c, the contact a'and the contact c', and the contact a" and the contact c" are connected.

Here, the motor 40 may be implemented as a BLDC motor with good efficiency. The integrated power control unit 20 of the present invention is described as being applied to a three-phase BLDC motor, but the integrated power control unit 20 of the present invention is not limited thereto, and can be used to drive an induction motor or other DC motor. It will be self-evident.

In addition, power switching transistors (e.g., MOS FETs) (Q1 to Q6) constituting the inverter 21 of the integrated power control unit 20 are high-speed based on phase-by-phase (U, V, W) PWM control signals input during acceleration. By performing a switching operation, the electric power discharged from the battery 30 is applied to a three-phase AC current to the electric motor 40, which is a BLDC electric motor. The motor 40 can efficiently drive the motor 40 by applying an appropriate voltage and a voltage of phase in consideration of the internal back EMF of the motor to the three-phase AC.

In the case of the three-phase electric motor 40, since three phases operate symmetrically with a delay of 120° or an advanced form around the neutral point, only one phase will be described in the present invention for convenience of explanation.

When the motor 40 is operated in the motor mode, the voltage and current are controlled from the outside of the motor 40 in consideration of the terminal voltage, frequency, and phase. In this case, this applies to both the case of slow acceleration of the vehicle, the case of a light load for constant speed driving, and the case of a heavy load for the vehicle rapidly accelerating or going up a steep hillside.

Although not shown in the drawing, when operating as the motor 40, the controller 10 provides software that can sufficiently track the internal resistance of the motor 40, the inductors 22 to 24, and the internal BACK-EMF by calculation. Using, it is desirable to optimally generate the PWM control signal.

That is, as shown in FIG. 4, the current and voltage supplied to the motor 40 are measured using the current sensor 71 and the voltage detector 72 connected between the motor 40 and the integrated power control unit 20. , By calculating this measured data and a mathematical model with the software, the internal resistance of the motor, inductor and BACK-EMF are accurately estimated. Then, by applying an appropriate terminal voltage of the power switch transistors Q1 to Q6 based on the estimation result, acceleration and deceleration of the motor 40 are freely implemented, while the energy of the motor is efficiently returned to the battery during deceleration. . Here, the technology for controlling the motor 40 at a desired speed by measuring whether the controller 10 is the desired voltage/current through constant current/voltage measurement, and changing the PWM control signal based on this is a technology for implementing a BLDC motor. It is decided to adopt and use the technology well known in the field as it is.

Next, when deceleration occurs in the motor mode, in order to charge the energy of the mechanical load connected to the motor 40 to the battery 30, the motor 40 is operated in a generator mode, and the energy is converted into electrical energy. To charge the battery 30. In other words, the current of the motor is driven so that a current of a phase different from that of the internal BACK EMF voltage 180° flows through it. At this time, the electric motor 40 operates as a generator, and the integrated power control unit 20 serves as a rectifier. The electric power generated and transmitted to the battery 30 may be operated in a state in which the electric motor 40 operates as a brake.

At this time, in the case of a light load, the power generation mode of the current does not greatly affect the system, so it can be driven with a brake simply by making a short circuit. Since this method has already been disclosed in Korean Publication No. 10-2019-0090309, it will be referred to. Even at this time, if the integrated power control unit 20 configures an appropriate alternating current of phase and voltage, the power of the motor 40 may flow into the battery 30 rather than being consumed inside the motor.

In this method, a brake can be applied to the motor 40 more powerfully than the method implemented in Korean Patent Laid-Open No. 10-2019-0090309, that is, a method of applying a brake by shorting the terminal of the motor 40 even under heavy load. Stronger electric power is sent from the electric motor 40 to the battery 30 so that the electric motor brakes over a wider range. In other words, power can be sent to the battery even in a wide operating range, heavy or light load, high speed or low speed, so that it can operate with a more energy-efficient brake.

Next, when the electric vehicle operates in the charging mode, the controller 10 controls the power switch unit 60 by outputting a power switch control signal as a power switching control signal. The power switches 61 to 63 for each phase perform a switching operation to interconnect the charger 50 and the integrated power control unit 20. That is, the input three-phase power line and the integrated power control unit 20 are interconnected. Here, all of the power switches 22 to 24 for each phase operate in the same manner at the same time. That is, the contact a and the contact b, the contact a'and the contact b', and the contact a" and the contact b" are connected.

In a state in which the charger 50 and the integrated power control unit 20 are connected, the input voltage of the charging terminal is checked as in step S101 to determine the type of the input voltage, that is, whether it is a DC input or an AC input. If you check the level of the input voltage, you can see whether it is DC or AC.

If the input voltage type is direct current as in step S102, go to step S103 to detect the state of the battery (temperature, voltage, current, voltage between battery cells) and input voltage, calculate the current control value by software and integrate it. By controlling the power control unit 20 with a PWM control signal, the charging current is controlled by a constant current. Then, after controlling the charging current, DC charging is started as in step S104. In a state in which the battery 30 is charged through the charging current control, the state of the battery and the input voltage are continuously monitored as in step S105, and charging is controlled while continuously observing whether an inappropriate operation occurs. Thereafter, when charging of the battery is completed as in step S106, the charging operation of the battery 30 is terminated. Here, the input power may be a commercial power source or a power source such as another vehicle or an ESS (Electric Stroage Systems), and a single power circuit can be used to accommodate all of a variety of DC power sources, thereby broadening the application range.

Meanwhile, if the input voltage type is not DC as a result of checking in step S102, it moves to step S107 and recognizes it as AC. When the input voltage is recognized as AC, it moves to step S108 and adjusts the PWM control signal of the integrated power control unit 20 in response to the voltage at the AC input terminal side, and controls the AC frequency and phase in response to the input voltage to control the AC input terminal. The power factor of the side is controlled close to 1. Here, if the power factor of the AC input terminal is controlled to be close to 1, the load on the power line can be reduced, so that an optimum current flow can be obtained. At this time, as in step S109, the three-phase AC input voltage is boosted through the power switch transistor of the integrated power control unit 20 through PWM control, and the battery 30 may be charged through the charging current control. Here, the current charged in the battery 30 becomes a pulsating current as in step S110. In the case of AC, in a state in which the battery 30 is charged through power factor control, the state of the battery and the input voltage are continuously monitored as in step S111, and charging is controlled while continuously observing whether an inappropriate operation occurs. Thereafter, when charging of the battery is completed as in step S112, the charging operation of the battery 30 is terminated. When the input voltage is AC charging, the inductors 22 to 24 connected to each phase perform a current smoothing, and serve as a circuit for the power switch transistor to obtain a desired current through adjustment of the AC current.

In this way, the charging power output from the charger 50 by the operation of the power switch becomes an optimal charging current through the power switch unit 60 and the integrated power control unit 20, and is charged in the battery 30, which is a storage battery.

Here, the battery 30 is actually composed of a plurality of high voltage batteries. It is preferable to configure it in a form having a rated voltage of as high as possible, and to allow sufficient current to flow through the motor 40 so that it is easy to obtain a strong driving force required for driving. The charger 50 receives an alternating current or direct current, or supplies a current of an optimum state suitable for the state of the battery 30, that is, a temperature or a state of charge, to the battery 30.

The charger 50 operates as a voltage and current control device for charging the input AC or DC power to the battery 30. Here, it is intended to employ a battery whose voltage is higher than the voltage input to the charger port. This is because when the battery is at high voltage, the wiring of the motor or the wires of copper or aluminum become thinner, making the system easier to manufacture. Therefore, more batteries are implemented with a higher voltage than the current one, and there will be more systems with a voltage higher than the voltage input from the charger in the future. In the present invention, when the charger 50 is a system higher than the input voltage, a circuit may be configured in which the circuit increases the input voltage and charges the battery 30.

According to the present invention described in detail above, first, it is possible to simply implement the entire system consisting of a charger and a motor drive with one driving motor and a controller of an electric vehicle. In all of the lower areas, a high-efficiency system can be implemented by facilitating current communication between the motor and the battery. Third, the charging function can also be implemented with an inexpensive system by reducing the number of accessories in the entire system as the motor driving part is responsible for that function. In particular, in the charging mode, the battery can be optimally charged by controlling the charging current according to the type of the input voltage.

Although the invention made by the present inventor has been described in detail according to the above embodiment, the present invention is not limited to the above embodiment, and it is common knowledge in the art that various changes can be made without departing from the gist of the invention. It is self-evident to those who have.

10: controller
20: integrated power control unit
21: inverter unit
22 to 24: inductor
30: battery
40: electric motor
50: charger
60: power switch unit
61 to 63: power switch
71: current sensor
72: voltage sensor

Claims (5)

If the operation mode of the electric vehicle is a charging mode, a controller configured to check a charging terminal input voltage to determine a type of the input voltage, and output a power switching control signal according to the determined type of input voltage to control charging;
According to the power switching control signal output from the controller, in the motor driving mode, the motor is driven with the discharged power of the battery, the energy of the motor is recovered and charged to the battery when decelerated, and the charging power supplied from the charger is input in the charging mode. An integrated power control unit for charging the battery by adjusting according to the voltage type and the battery state; And
And a power switch unit interposed between the integrated power control unit and the electric motor and the charger to selectively connect the integrated power control unit to the electric motor and the charger according to a power switching control signal of the controller. Adaptive charging control device through automatic DC/AC recognition of automobiles.
If the operation mode of the electric vehicle is the charging mode, the input voltage of the charging terminal is checked to automatically recognize whether the input voltage is AC or DC, and according to the type of the automatically recognized input voltage, the electric motor is driven using the power switching control signal and the battery An adaptive charging control device through automatic DC/AC recognition of an electric vehicle, comprising: a controller for charging a battery according to an input voltage type and a battery state by controlling an integrated power control unit for charging. The direct current of an electric vehicle according to claim 1, wherein the power switching control signal includes a PWM power control signal for controlling the integrated power control unit in a charging mode and a power switch control signal for controlling switching of the power switch unit. /Adaptive charging control device through automatic recognition of exchange.
A method of charging and controlling a battery of an electric vehicle using the adaptive charging control device through automatic DC/AC automatic recognition of an electric vehicle according to any one of claims 1 to 3, comprising:
(a) determining the type of the input voltage by checking the input voltage of the charging terminal in the charging mode in the controller;
(b) controlling charging of the battery based on current control and battery state if the input voltage type is DC as a result of the determination in step (a); And
(c) If the type of the input voltage is AC as a result of the determination in step (a), the charging of the battery is controlled based on power factor control and battery state. Adaptive charging control method.
In claim 4, the step (c) is a direct current / AC automatic of an electric vehicle, characterized in that the power power factor of the AC input terminal is controlled close to 1 by controlling the AC frequency and the phase through PWM control of the integrated power control unit. Adaptive charging control method through recognition.

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