CN102891522B - Dual-energy-storage device with vehicle-mounted charging function - Google Patents

Abstract

The invention relates to a dual-energy-storage device with a vehicle-mounted charging function. The dual-energy-storage device comprises a main energy storage unit, an auxiliary energy storage unit, a charging unit, a bidirectional half-bridge DC/DC (Direct Current) converter and a PWM (Pulse Width Modulation) control unit, wherein the bidirectional half-bridge DC/DC converter is connected between the main energy storage unit and the auxiliary energy storage unit so as to provide a power supply path and realize energy transfer between the energy storage units, the charge unit comprises a charge interface and a rectifying module, an alternating-current input end of the rectifying module is connected with the charging interface, and a direct-current output end of the rectifying module is connected with an output end of the bidirectional half-bridge DC/DC converter. The dual-energy-storage device not only can be used to realize control over a hybrid energy system, but also has a vehicle-mounted charging function, parts of a power assembly are reduced so that an electric vehicle system is compacter, and the system cost is reduced.

Description

Dual Energy Storage with Onboard Charging

technical field

The invention relates to a dual energy storage device with a vehicle charging function.

Background technique

New energy vehicles promote the rapid development of new energy vehicles in my country through energy diversification, power electrification, and clean emissions. In view of the technical characteristics of the existing vehicle power system, the vehicle power system with the technical characteristics of various energy sources and power complementation has become the mainstream of the development of new energy vehicle technology.

At present, restricted by the development of battery technology, it is difficult for a single energy storage system to simultaneously meet the energy and power requirements of new energy vehicles during operation. Energy vehicles have dual requirements on the energy and power of energy storage systems, which can improve the performance of new energy vehicles to the greatest extent. The core of the composite energy control strategy lies in the rational distribution of power between the two energy storage systems, that is, to adopt a reasonable control strategy to give full play to the respective characteristics of the two energy storage systems, prolong the service life of the energy storage system, and improve the system's efficiency and fuel consumption. Economical, and the powertrains of new energy vehicles make new energy vehicles highly complex, which brings many problems to high-voltage safety, heat dissipation, layout, and anti-interference of the whole vehicle, and increases the cost of the whole vehicle. Effective use of space is reduced.

Contents of the invention

The purpose of the present invention is to provide a dual energy storage device with on-board charging function to solve the problem of low utilization efficiency of new energy in the prior art.

In order to achieve the above object, the solution of the present invention is to provide a dual energy storage device with on-board charging function, including a main energy storage unit and an auxiliary energy storage unit, the main energy storage unit is connected to the dual energy storage device The output terminal, the auxiliary energy storage unit is connected to the input terminal of the bidirectional half-bridge DC/DC converter, the output terminal of the bidirectional half-bridge DC/DC converter is connected to the output terminal of the dual energy storage device through a switch, and the dual The output end of the energy storage device is used to connect with the power supply motor controller of the electric motor;

The dual energy storage device is also provided with a control unit for controlling the bidirectional half-bridge DC/DC converter;

The dual energy storage device is provided with a charging unit, the charging unit includes a rectification module and a charging interface, the AC input terminal of the rectification module is connected to the charging interface, and its DC output terminal is connected to the bidirectional half-bridge DC/DC converter. output.

Further, the bidirectional half-bridge DC/DC converter includes a capacitor, an inductor and two IGBT modules connected in series, the capacitor is connected in parallel to both ends of the main energy storage unit, and one end of the inductor is connected to the main energy storage unit The positive pole of the unit, the other end of which is connected to the series connection point of the drain and source of the two series-connected IGBT modules, and the other set of drains and sources of the two series-connected IGBT modules are connected to the dual energy storage device output terminal.

The control unit is a PWM control unit.

The auxiliary energy storage unit is a storage battery, and the main energy storage unit is a super capacitor.

The rectification module is a three-phase rectifier.

In the present invention, a bidirectional half-bridge DC/DC converter is connected between the two energy storage units. When the energy of the main energy storage unit is insufficient, the auxiliary energy storage unit can transfer energy to the main energy storage unit through the bidirectional half-bridge DC/DC converter. In the above, when the energy braking recovery of the main energy storage unit is excessive, the energy can be transferred to the auxiliary energy storage unit through the bidirectional half-bridge DC/DC converter, and the energy can be transferred between the energy storage units to realize the complementary advantages of energy sources Effective utilization improves the efficiency of each energy storage unit.

Moreover, the device also integrates a rectification module and a charging interface. When connected to an external power grid, the rectification module rectifies the alternating current of the charging interface into direct current, realizing the on-board charging function, and realizing the mileage of the vehicle by replenishing power to the battery.

The invention can not only realize the control of the composite energy system, but also has the function of the on-board charging system to charge the energy storage system, can improve the utilization efficiency of new energy, and reduce the power assembly components, making the electric vehicle system more compact and reducing the system cost.

Description of drawings

Fig. 1 is a circuit schematic diagram of the present invention;

Fig. 2 is a schematic circuit diagram of an embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with the accompanying drawings.

The schematic diagram of the circuit shown in Figure 1 includes a main energy storage unit 1, an auxiliary energy storage unit 2, a bidirectional half-bridge DC/DC converter 3 and its control unit 6, a switch 4, a rectifier module 5 and a charging interface 7. Shown in the middle dotted box is the power supply motor controller.

The bidirectional half-bridge DC/DC converter is connected between the main energy storage unit and the auxiliary energy storage unit through a switch, and the signal output terminal of the control unit is connected to the gate trigger terminal of the IGBT in the bidirectional half-bridge DC/DC converter, rectifying The AC input terminal of the module is connected to the charging interface, the DC output terminal is connected between the switch and the bidirectional half-bridge DC/DC converter, and the output terminals of the main energy storage unit and the bidirectional half-bridge DC/DC converter are connected to the dual energy storage device. Output terminal, the output terminal of the double energy storage device is used to connect with the power supply motor controller of the electric motor.

As shown in Figure 2, in this embodiment, the main energy storage unit is a super capacitor, the auxiliary energy storage unit is a battery, the rectification module is a three-phase rectifier, the control unit is a PWM control unit, and the bidirectional half-bridge DC/DC converter is a battery and The supercapacitor provides a power supply path, and the battery and the supercapacitor can transfer energy to each other through the bidirectional half-bridge DC/DC converter; when the bidirectional half-bridge DC/DC converter and its PWM control unit are working, they can supply power to the motor system and drive the vehicle. Braking energy recovery can also be performed; the device also integrates a charging interface and a three-phase rectifier, which can charge the battery through a bidirectional half-bridge DC/DC converter. When charging is required, the switch is turned off.

The specific working process is as follows:

During normal driving, the whole vehicle provides low-voltage 24V, the PWM control unit works, and performs self-inspection. After the self-inspection passes, pre-charge and power on. According to the energy demand of the vehicle, the PWM control unit receives the command of the vehicle and sends out a PWM control signal. On the one hand, when the energy of the super capacitor is insufficient, the PWM control unit transfers the energy in the battery to the super capacitor through a bidirectional half-bridge DC/DC converter. And it can be used for various loads; on the other hand, when the energy of the supercapacitor brakes and recovers excess energy, the PWM control unit transfers the energy in the supercapacitor to the battery through a bidirectional half-bridge DC/DC converter, and finally realizes the supercapacitor and battery energy transfer between them.

When the vehicle is stopped for charging, the charging interface is connected to the external plug-in gun. After the charging connection is confirmed, the charging auxiliary power is obtained through the three-phase rectifier to supply power for the PWM control unit and the internal contactor, and then self-test is performed. After the self-test passes, the external AC power The direct current is rectified by the three-phase rectifier, and then the bidirectional half-bridge DC/DC converter is controlled by the PWM control unit to realize the function of charging the battery.

At low speed (below 10~30km/h) and during starting, the dual energy storage device supplies power to the motor, and after the vehicle reaches a certain speed, the engine and the dual energy storage device jointly provide power for the vehicle. In the process of low-speed operation and starting, especially the starting process, the double energy storage device of the present invention is used to start by relying on the high torque generated by the electric motor. Compared with the 24V low-voltage starter, the starting fuel consumption is large and the starting torque is small, and the starting effect is good and the efficiency is high. High; moreover, compared with the way of charging the supercapacitor by generating electricity with the engine, the dual energy storage device of the present invention avoids the energy loss of kinetic energy-electric energy conversion, and saves energy.

In summary, the present invention realizes the effective integration of the energy transfer of the two energy storage units and the on-board charging. The main energy storage unit and the auxiliary energy storage unit can realize the mutual transfer of energy. At the same time, the device integrates the rectification module and the charging interface, which can Realize the function of on-board charging.

Claims (5)

1. A dual energy storage device with on-board charging function, characterized in that it comprises a main energy storage unit and an auxiliary energy storage unit, the main energy storage unit is connected to the output terminals of the dual energy storage devices, and the auxiliary energy storage unit The energy storage unit is connected to the input end of the bidirectional half-bridge DC/DC converter, and the output end of the bidirectional half-bridge DC/DC converter is connected to the output end of the double energy storage device through a switch, and the output end of the double energy storage device Used to connect with the power supply motor controller of the motor; The dual energy storage device is also provided with a control unit for controlling the bidirectional half-bridge DC/DC converter; The dual energy storage device is provided with a charging unit, the charging unit includes a rectification module and a charging interface, the AC input terminal of the rectification module is connected to the charging interface, and its DC output terminal is connected to the bidirectional half-bridge DC/DC converter. output terminal; The main energy storage unit and the auxiliary energy storage unit transfer energy to each other through a bidirectional half-bridge DC/DC converter; the device also integrates a charging interface and a rectifier module. When charging is required, the switch is turned off, and the bidirectional half-bridge DC/DC conversion to charge the auxiliary energy storage unit. 2. The dual energy storage device with on-board charging function according to claim 1, wherein the bidirectional half-bridge DC/DC converter comprises a capacitor, an inductor and two series-connected IGBT modules, and the capacitor is connected in parallel to The two ends of the auxiliary energy storage unit, one end of the inductor is connected to the positive pole of the auxiliary energy storage unit, and the other end is connected to the series connection point of the drain and source of the two series-connected IGBT modules, the two Another set of drains and sources of the series connected IGBT modules are connected to the output terminals of the dual energy storage devices. 3. The dual energy storage device with vehicle charging function according to claim 1, wherein the control unit is a PWM control unit. 4. The dual energy storage device with on-board charging function according to claim 1, wherein the auxiliary energy storage unit is a storage battery, and the main energy storage unit is a supercapacitor. 5. The dual energy storage device with vehicle charging function according to claim 1, characterized in that the rectification module is a three-phase rectifier.