CN103219764A - Vehicular charging system for electric automobile, and charging control method thereof - Google Patents

Abstract

The invention discloses a vehicle-mounted charging system for electric vehicles and a charging control method thereof. , driving motor, and rectification and filtering circuit modules are connected to realize the two-way flow of charging and discharging energy. The feedback signal acquisition module transmits the monitored data related to the battery, external power supply access and braking energy generation to the central controller. The central controller analyzes and compares the data, and then controls the bidirectional DC/DC converter module and the charging selection switch module to complete the charging process of the on-board battery by driving the protection circuit module. The invention makes the entire on-board charging system miniaturized and intelligentized, satisfies the current requirements of diversified charging modes of electric vehicles, and prolongs the mileage of the electric vehicles on one charge.

Description

An electric vehicle on-board charging system and charging control method thereof

technical field

The invention relates to the technical field of energy supply for electric vehicle on-board batteries, in particular to an electric vehicle on-board charging system and a charging control method thereof.

Background technique

With the increasingly prominent energy and environmental problems, new energy vehicles have ushered in unprecedented development opportunities, and electric vehicles are an ideal daily public transportation tool. The application of electric vehicles effectively solves the two major problems of energy and environment. After the large-scale promotion and application of electric vehicles, there are technical requirements for charging the battery modules in the battery pack, because the on-board charging system greatly affects the operating quality of electric vehicles. At present, the on-board charging system of electric vehicles is heavy in weight, large in size, takes a long time to charge, and does not match the operation of the whole vehicle. In view of the current situation, it has become an important research direction to develop a small, lightweight, intelligent and fast multi-functional vehicle charging system. Moreover, most of the current electric vehicle on-board charging systems only consider the external charging power supply to supply energy, and do not consider the recovery and charging of braking energy.

The market is badly in need of a vehicle-mounted charging system for electric vehicles with a simple structure that can solve the above-mentioned deficiencies.

Contents of the invention

The purpose of the present invention is to overcome the shortcomings and deficiencies of the above-mentioned prior art, and provide a vehicle-mounted charging system for electric vehicles with a simple structure and compatible with multiple energy supply modes.

In order to solve the above technical problems, the technical solution adopted in the present invention is: a vehicle-mounted charging system for electric vehicles, including a vehicle-mounted storage battery, a drive motor, and a rectification and filtering circuit module, and its structural feature is that it also includes a bidirectional DC/DC converter module are respectively connected with the on-board battery, drive motor, and rectification and filtering circuit module, and are used to convert the voltage value of the external power supply energy and braking energy into a voltage amplitude that can meet the charging requirements of the on-board battery after processing, and the feedback signal acquisition module Transmit the monitored data related to the battery, external power supply access and braking energy generation to the central controller, the central controller analyzes and compares the data and then controls the bidirectional DC/DC converter through the drive protection circuit module The module and the charging selection switch module work to complete the charging process of the on-board storage battery.

The bidirectional DC/DC converter module is an electric vehicle on-board power converter with bidirectional energy flow function. It can not only make the battery supply energy to the outside, but also make energy supply to the battery from the outside. Two full-bridge circuits are used. The circuit Each switch in the device uses an insulated gate bipolar transistor (IGBT) with an antiparallel diode and capacitor. After the central controller analyzes and processes the feedback signal, the direction of energy flow is determined by controlling the switching state of each IGBT tube through PWM pulses, thereby realizing the function of the entire vehicle charging system.

The feedback signal acquisition module includes a first voltage sensor, a first current sensor and a battery temperature sensor for monitoring the voltage, current and temperature of the vehicle battery, a second voltage sensor and a second current sensor for monitoring the external power supply, and The third voltage sensor and the third current sensor are used to monitor the braking reverse power supply of the drive motor.

The charging selection switch module includes two sets of single-pole double-throw switches, and the central controller controls the first single-pole double-throw switch and the second single-pole double-throw switch to be set to the left or right at the same time to switch between the two charging modes.

The on-vehicle storage battery and the bidirectional DC/DC converter module are also provided with a battery discharge device, which is used to eliminate the polarization phenomenon of the battery during fast charging.

A control method for realizing charging of an electric vehicle on-board battery by using the above-mentioned on-board charging system for electric vehicles, comprising the following steps:

1) The central controller inquires the capacity and temperature of the on-board battery through the feedback signal acquisition module;

2) When the battery capacity and temperature meet the charging conditions, the central controller selects the charging mode by controlling the charging selection switch module;

3) When an external power supply is connected, the central controller controls the first single-pole double-throw switch and the second single-pole double-throw switch in the charging selection switch module to be set to the right at the same time, and the energy of the external power supply is converted by the bidirectional DC/DC The charger module charges the on-board battery;

4) When there is braking energy that needs to be recovered, the central controller controls the first SPDT switch and the second SPDT switch in the charging selection switch module to be set to the left at the same time, and the braking energy passes through the bidirectional DC/ The DC converter module charges the on-board battery;

5) When charging ends, the central controller controls the charging selection switch module to turn off the first single-pole double-throw switch and the second single-pole double-throw switch.

Wherein, the step 2) is realized through the following steps:

2-1) Whether the temperature of the battery temperature sensor is within the appropriate range;

2-2) Whether the first voltage sensor and the first current sensor are within the appropriate range;

2-3) The above conditions are met to start monitoring the second voltage sensor and the second current sensor, as well as the third voltage sensor and the third current sensor;

2-4) Turn on the charging selection switch module to prepare for charging mode selection.

Said step 3) also includes the following steps:

3-1) When the voltage and current monitored by the second voltage sensor and the second current sensor exceed a certain range, the central controller will control the on-board battery discharge device to start working, and prevent battery polarization through discharge pulses.

Compared with the prior art, the present invention can not only meet the requirements of diversification of electric vehicle charging methods, but also make the entire vehicle charging system miniaturized and intelligent, effectively reduce costs, and at the same time extend the mileage of electric vehicles on one charge , has great practical value.

Description of drawings

FIG. 1 is a schematic diagram of the composition and structure of the charging system of the present invention;

2 is a schematic diagram of the circuit principle of the charging system of the present invention;

Fig. 3 is a schematic diagram of the working flow of the charging system of the present invention.

In the attached picture:

1-vehicle battery; 2-drive motor; 3-drive protection circuit module; 4-bidirectional DC/DC converter module; 5-rectification filter circuit module; 6-central controller; 7-feedback signal acquisition module; 8-battery Discharging device; U1-first voltage sensor; U2-second voltage sensor; U3-third voltage sensor; I1-first current sensor; I2-second current sensor; I3-third current sensor; T1-battery temperature sensor ; SW1-first single-pole double-throw switch; SW2-second single-pole double-throw switch.

Detailed ways

Embodiments of the present invention will be further described below in conjunction with the accompanying drawings.

Referring to the accompanying drawings 1 and 2, a vehicle-mounted charging system for electric vehicles described in the present invention includes a vehicle-mounted storage battery 1, a drive motor 2, a drive protection circuit module 3, a bidirectional DC/DC converter module 4, and a rectification and filtering circuit Module 5, central controller 6, feedback signal acquisition module 7, battery discharge device 8 and charging selection switch module.

Fig. 1 is a system connection diagram and an energy flow diagram of the present invention, the bidirectional DC/DC converter module 4 is connected to the vehicle battery 1, the drive motor 2, and the rectification and filtering circuit module 5 respectively, and is used to pass through the rectification and filtering circuit The grid energy input by the external power supply converted by the module 5 and the braking energy of the drive motor 2 are processed and converted into charging energy that can meet the charging requirements of the vehicle battery 1. The feedback signal acquisition module 7 connects the monitored battery, external power supply and The relevant data generated by the braking energy is transmitted to the central controller 6, and the central controller 6 analyzes and compares the data and controls the bidirectional DC/DC converter module 4 and the charging selection switch module to work by driving the protection circuit module to After completing the charging process of the on-vehicle battery 1, the on-vehicle battery 1 and the bidirectional DC/DC converter module 4 are also provided with a battery discharge device 8, which can be used to eliminate the polarization phenomenon of the battery when using an external power input for fast charging. At the same time, the driving energy of the vehicle battery 1 can also be provided to the driving motor 2 through the bidirectional DC/DC converter module 4 .

FIG. 2 specifically describes the implementation circuit diagram of the system. The bidirectional DC/DC converter module 4 adopts two full bridges composed of switching tubes Q ₁ -Q ₈ controlled by the central controller 6 . The path selection of the energy supply mode of the on-board storage battery 1 is determined by two single-pole double-throw switches SW1 and SW2 controlled by the central controller 6 . When the energy is supplied by the energy of the external power supply, the selection switch is set to the right at the same time, and the charging main circuit is connected. When the energy is supplied by the braking energy of the electric vehicle, the selection switch is set to the left at the same time, and the charging main circuit is connected.

The feedback signal acquisition module 7 includes a first voltage sensor U1, a first current sensor I1 and a battery temperature sensor T1 for monitoring the voltage, current and temperature of the vehicle battery 1, and a second voltage sensor U2 and a second current sensor for monitoring the external power supply. sensor I2, and a third voltage sensor U3 and a third current sensor I3 for monitoring the braking reverse power supply of the drive motor 2 . Here, the acquisition of the battery capacity SOC of the on-vehicle battery 1 is obtained through the battery management system. The present invention transmits relevant voltage and current signals in the charging main circuit to the central controller 6 through the above sensors, and the central controller 6 makes different judgments through these data to realize the normal operation of the entire charging system.

The battery discharge device 8 includes a switching element Q0 and an inductance T0. When the on-board charging system is connected to an external power source for fast charging, the switching tube Q0 is controlled to discharge the battery with a large reverse pulse to eliminate the polarization phenomenon and prevent the battery temperature from rising too much. Affect battery life.

The working process of this system is shown in Figure 3. The central controller 6 inquires the capacity and temperature of the on-board battery 1 through the feedback signal acquisition module 7. First, it detects whether the temperature of the battery temperature sensor T1 is within an appropriate range. Detect whether the first voltage sensor U1 and the first current sensor I1 are within the appropriate range, and the above conditions are met to start monitoring the second voltage sensor U2 and the second current sensor I2, as well as the third voltage sensor U3 and the third current sensor I3, and start charging Select the switch module to prepare for charging mode selection.

When an external power supply is connected, the central controller 6 controls the first single-pole double-throw switch SW1 and the second single-pole double-throw switch SW2 in the charging selection switch module to be set to the right at the same time, and the energy of the external power supply passes through the bidirectional DC/DC The converter module 4 charges the on-board storage battery 1. At this time, if the voltage and current monitored by the second voltage sensor U2 and the second current sensor I2 exceed a certain range, the central controller 6 will control the battery discharge device 8 to start working , to prevent battery polarization by discharge pulses.

When it is detected that the battery capacity is full or the data signal is not within the normal range, the main circuit should be stopped, and the charging system should be tested to meet the charging conditions before charging.

When there is braking energy generation that requires reverse power supply charging, after the central controller 6 controls and accepts the signal data of the sensors U3, I3, when the charging condition is satisfied, the first single-pole double-throw switch (SW1) in the charging selection switch module ) and the second SPDT switch SW2 are set to the left at the same time, and the braking energy is charged to the on-vehicle battery 1 through the bidirectional DC/DC converter module 4 .

If the charging condition is not satisfied, the central controller 6 controls the charging selection switch module to turn off the first SPDT switch SW1 and the second SPDT switch SW2, the charging process ends, and then turn on the system until the system meets the conditions The main circuit.

The above-mentioned embodiments should be understood that these embodiments are only used to illustrate the present invention more clearly, and are not intended to limit the scope of the present invention. After reading the present invention, those skilled in the art will understand the various equivalent forms of the present invention All modifications fall within the scope defined by the appended claims of the present application.

Claims (8)

1. A vehicle-mounted charging system for an electric vehicle, comprising a vehicle-mounted storage battery (1), a drive motor (2), and a rectifying and filtering circuit module (5), characterized in that it also includes a bidirectional DC/DC converter module (4), respectively Connected to the on-board battery (1), drive motor (2), and rectification and filtering circuit module (5), the feedback signal acquisition module (7) transmits the monitored relevant data to the central controller (6), and the central control The device (6) analyzes and compares the data and controls the bidirectional DC/DC converter module (4) and the charging selection switch module to complete the charging process of the vehicle battery (1) by driving the protection circuit module (3). 2. An electric vehicle on-board charging system according to claim 1, characterized in that, the bidirectional DC/DC converter module (4) adopts two full-bridge circuits, and each switch tube in the circuit adopts a Insulated gate bipolar transistors with antiparallel diodes and capacitors can control the switching tubes through the central controller (6) to realize bidirectional flow of energy. 3. An electric vehicle on-board charging system according to claim 1, characterized in that the feedback signal acquisition module (7) includes a first voltage sensor (U1) for monitoring the voltage, current and temperature of the on-board battery, The first current sensor (I1) and the battery temperature sensor (T1), the second voltage sensor (U2) and the second current sensor (I2) for monitoring the external power supply, and the second sensor for monitoring the braking reverse power supply of the drive motor Three voltage sensors (U3) and a third current sensor (I3). 4. The vehicle-mounted charging system for electric vehicles according to claim 1, wherein the charging selection switch module includes two sets of single-pole double-throw switches, and the first single-pole double-throw switch (SW1) is controlled by the central controller. ) and the second SPDT switch (SW2) are simultaneously set to the left or to the right to switch between the two charging modes. 5. An electric vehicle on-board charging system according to claim 1, characterized in that a battery discharge device ( 8), used to eliminate the polarization of the battery during fast charging. 6. A control method utilizing the electric vehicle on-board charging system described in any one of claims 1 to 5 to realize the charging of the electric vehicle on-board storage battery, characterized in that it comprises the following steps: 1) The central controller (6) queries the capacity and temperature of the on-board battery (1) through the feedback signal acquisition module (7); 2) When the battery capacity and temperature meet the charging conditions, the central controller (6) selects the charging mode by controlling the charging selection switch module; 3) When an external power supply is connected, the central controller (6) controls the first single-pole double-throw switch (SW1) and the second single-pole double-throw switch (SW2) in the charging selection switch module to be set to the right at the same time, and the external power supply The energy is charged to the vehicle battery (1) through the bidirectional DC/DC converter module (4); 4) When there is braking energy that needs to be recovered, the central controller (6) controls the first single-pole double-throw switch (SW1) and the second single-pole double-throw switch (SW2) in the charging selection switch module to be set to the left at the same time, The braking energy charges the vehicle battery (1) through the bidirectional DC/DC converter module (4); 5) When charging ends, the central controller (6) controls the charging selection switch module to turn off the first single-pole double-throw switch (SW1) and the second single-pole double-throw switch (SW2). 7. A control method for charging the on-board battery of an electric vehicle according to claim 6, wherein the step 2) is realized by the following steps: 2-1) Whether the temperature of the first temperature sensor (T1) is within the appropriate range; 2-2) Whether the first voltage sensor (U1) and the first current sensor (I1) are within the appropriate range; 2-3) The above conditions are met to start monitoring the second voltage sensor (U2) and the second current sensor (I2), as well as the third voltage sensor (U3) and the third current sensor (I3); 2-4) Turn on the charging selection switch module to prepare for charging mode selection. 8. A control method for charging an electric vehicle on-board battery according to claim 6, wherein said step 3) further comprises the following steps: 3-1) When the voltage and current monitored by the second voltage sensor (U2) and the second current sensor (I2) exceed a certain range, the central controller (6) will control the on-board battery discharge device (8) to start working , to prevent battery polarization by discharge pulses.

Images