阅读说明：本技术 燃料电池增程式混合电动汽车供电系统 (Fuel cell range-extending hybrid electric vehicle power supply system ) 是由 吴晓刚 张磊 于 2021-08-13 设计创作，主要内容包括：燃料电池增程式混合电动汽车供电系统,属于电动汽车供电技术领域。本发明解决了燃料电池混合动力汽车在低温环境下,动力电池放电稳定性差的问题。本发明包括三端口DC/DC变换器、动力电池驱动电机控制器、电池加热膜、燃料电池和变换器控制电路；三端口DC/DC变换器的三个端口分别连接电池加热膜的供电端、燃料电池的电源端和驱动电机控制器的供电端；变换器控制电路用于控制三端口DC/DC变换器中开关管的开关,使三端口DC/DC变换器处于不同的工作模式；所述电池加热膜设置在动力电池的外侧,用于为动力电池加热；动力电池用于为驱动电机控制器供电,本发明适用于混合电动汽车供电。(A fuel cell extended range hybrid electric vehicle power supply system belongs to the technical field of electric vehicle power supply. The invention solves the problem of poor discharge stability of the power battery of the fuel battery hybrid electric vehicle in a low-temperature environment. The invention comprises a three-port DC/DC converter, a power battery driving motor controller, a battery heating film, a fuel cell and a converter control circuit; three ports of the three-port DC/DC converter are respectively connected with a power supply end of a battery heating film, a power supply end of a fuel battery and a power supply end of a driving motor controller; the converter control circuit is used for controlling the switch of a switch tube in the three-port DC/DC converter to enable the three-port DC/DC converter to be in different working modes; the battery heating film is arranged on the outer side of the power battery and used for heating the power battery; the power battery is used for supplying power for the driving motor controller, and the invention is suitable for supplying power for the hybrid electric vehicle.)

1. The fuel cell extended-range hybrid electric vehicle power supply system is characterized by comprising a three-port DC/DC converter, a power cell, a driving motor controller UO1, a cell heating membrane UO2, a fuel cell Uin and a converter control circuit;

three ports of the three-port DC/DC converter are respectively connected with a power supply end of a battery heating film, a power supply end of a fuel battery and a power supply end of a driving motor controller UO 1;

the converter control circuit is used for controlling the switch of a switch tube in the three-port DC/DC converter to enable the three-port DC/DC converter to be in different working modes;

the battery heating film UO2 is arranged on the outer side of the power battery and used for heating the power battery;

the power battery is used for supplying power to the drive motor controller UO 1; the three-port DC/DC converter includes: a Buck-Boost circuit, a half-bridge structure and an additional circuit;

the Buck-Boost circuit includes: a diode D1, a switch tube S1, an inductor L and a capacitor C1;

the half-bridge structure comprises: a switch tube S2, a switch tube S3;

the additional circuit includes: a switch tube S4, a diode D2 and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with the source electrode of the switch tube S3, the drain electrode of the switch tube S3 is also connected with the drain electrode of the switch tube S2 through a capacitor C2, and two ends of the capacitor C2 are respectively connected with two power supply ends of a cell heating film UO 2;

the source electrode of the switching tube S2 is also connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S3 is further connected with the cathode of the diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, and the drain of the switch tube S4 is connected with the other end of the inductor L;

the source of the switch tube S4 is further connected to the cathode of the diode D1, the anode of the diode D1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the drain of the switch tube S4;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

2. The fuel cell extended range hybrid electric vehicle power supply system of claim 1, wherein the three-port DC/DC converter comprises: a single-input single-output mode and a single-input dual-output mode.

3. The power supply system of the fuel cell extended-range hybrid electric vehicle as claimed in claim 2, wherein in the single-input single-output mode a, the fuel cell alone supplies power to the cell heating membrane Uo 2;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 and the switch tube S4 are kept on, and the switch tube S3 is kept off;

t_onthe state is as follows: the switching tube S1 is in a conducting state, and the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S1 is also connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with the source of the switch tube S1;

t_offthe state is as follows: the switching tube S1 is in an off state, and the equivalent circuit includes: a switch tube S2, a capacitor C2, an inductor L, a switch tube S4 and a diode D2;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, the drain of the switch tube S4 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of the switch tube S2; two ends of the capacitor C2 are also respectively connected with two power supply ends of the battery heating film UO 2;

in the single-input single-output mode b, the fuel cell independently supplies power to the drive motor controller Uo 1;

the switching tube S1, the switching tube S2 and the switching tube S3 are controlled by the PWM signal, and the switching tube S4 is kept turned off;

t_onthe state is as follows: the switch tube S1 and the switch tube S2 are in a conducting state, the switch tube S3 is in an off state, and the equivalent circuit includes: switch tube S1 and switchA tube S2, an inductor L and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor;

t_offthe state is as follows: the switch tube S1 and the switch tube S2 are in an off state, the switch tube S3 is in an on state, and the equivalent circuit includes: a switch tube S3, an inductor L, a capacitor C1, a diode D1 and a diode D2;

the source of the switch tube S3 is connected to one end of the inductor L, the other end of the inductor L is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the drain of the switch tube S3, and the two ends of the capacitor C1 are respectively connected to the two power supply ends of the drive motor controller Uo 1.

4. The fuel cell extended range hybrid electric vehicle power supply system of claim 2, wherein in a single-input and dual-output mode of the three-port DC/DC converter, the fuel cell independently supplies power to the battery heating film Uo2 and the driving motor controller Uo 1;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 is switched on, and the switch tube S3 and the switch tube S4 are switched off;

t_onin a state where the switching tube S1 is in a conducting state, the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L, a capacitor C2 and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with one end of a capacitor C2;

two ends of the capacitor C1 are respectively connected with two power supply ends of a driving motor controller UO 1;

t_offin the state that the switching tube S1 is in the off state, the equivalent circuit includes: a switch tube S2, an inductor L, a capacitor C2, a diode D1, a diode D2 and a capacitor C1;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of a diode D2 is connected with the cathode of a diode D1, the anode of a diode D1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of a switch tube S2;

two ends of the capacitor C2 are respectively connected with two power supply ends of the battery heating film UO 2;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

5. The fuel cell extended-range hybrid electric vehicle power supply system according to claim 3 or 4, wherein the converter control circuit comprises a protection circuit (201), a DSP system (202), a voltage sensor group (203), a current sensor group (204) and a temperature sensor (205);

the voltage sensor group (203) comprises a plurality of voltage sensors which respectively collect the output voltage of the fuel cell Uin, the output voltage of the power cell and the input voltage of the cell heating film Uo 2;

the current sensor group (204) comprises a plurality of current sensors which respectively collect the output current of the fuel cell Uin, the output current of the power cell and the input current of the cell heating film Uo 2;

the temperature sensor (205) is used for collecting the surface temperature of the power battery and sending a collected temperature signal to the DSP system (202);

a target voltage signal input end of the DSP system (202) inputs a target voltage;

a switching tube driving signal output end of the DSP system (202) sends a switching tube driving signal to a signal input end of the three-port DC/DC converter through a protection circuit (201);

the DSP system (202) judges whether the power battery needs to be heated or not by utilizing the surface temperature of the power battery, calculates the power required by a battery heating film if the power battery needs to be heated, and acquires the power required by the whole vehicle through the whole vehicle controller;

the DSP system (202) also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input single-output mode a when the automobile is not started and the power battery needs to be heated;

the DSP system (202) also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input single-output mode b when the automobile normally runs and the power battery does not need to be heated;

the DSP system (202) also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input double-output mode when the temperature of the automobile is reduced to the warning temperature in the driving process;

the DSP system (202) also obtains the power required by the whole vehicle, the power required by the battery heating film and the output power of the power battery according to the whole vehicle controller, adjusts the PWM signal in real time and adjusts the output power of the fuel battery.

Technical Field

The invention belongs to the technical field of electric automobile power supply.

Background

The fuel cell range-extended electric automobile is formed by mixing a fuel cell and a power cell, and a range extender is installed on the basis of a pure electric automobile and is an auxiliary energy device capable of generating electricity to charge a vehicle-mounted power storage battery. Compared with the traditional pure electric vehicle, the service life of the battery and the endurance mileage of the vehicle are prolonged; compared with a pure fuel cell automobile, the dynamic response speed of the system is improved, and power supply can be obtained at the moment of needing high power, such as starting, rapid acceleration, steep slope climbing and the like. Therefore, in the current new energy vehicle configuration, the fuel cell extended range electric vehicle is an important development route.

When the fuel cell extended range electric vehicle runs in a low-temperature environment, the power cell is unable to charge and poor in discharging power, and the fuel cell has a good low-temperature starting characteristic. The three-port converter is an integrated converter capable of being connected with three ports simultaneously, and has the advantages of compact structure, small volume cost, convenience for centralized control and the like. Therefore, the three-port DC/DC converter for the fuel cell hybrid electric vehicle can meet the low-temperature preheating of the power cell by the fuel cell, and simultaneously, the cost is reduced as much as possible and the stability is improved.

Disclosure of Invention

The invention aims to solve the problem that a power battery of a fuel battery hybrid electric vehicle is poor in discharging stability in a low-temperature environment, and provides a power supply system of a fuel battery range-extended hybrid electric vehicle.

The invention relates to a fuel cell extended-range hybrid electric vehicle power supply system, which comprises a three-port DC/DC converter, a driving motor controller UO1, a cell heating film UO2, a fuel cell Uin and a converter control circuit;

three ports of the three-port DC/DC converter are respectively connected with a power supply end of a battery heating film, a power supply end of a fuel battery and a power supply end of a driving motor controller UO 1;

the converter control circuit is used for controlling the switch of a switch tube in the three-port DC/DC converter to enable the three-port DC/DC converter to be in different working modes;

the battery heating film UO2 is arranged on the outer side of the power battery and used for heating the power battery;

the three-port DC/DC converter includes: a Buck-Boost circuit, a half-bridge structure and an additional circuit;

the Buck-Boost circuit includes: a diode D1, a switch tube S1, an inductor L and a capacitor C1;

the half-bridge structure comprises: a switch tube S2, a switch tube S3;

the additional circuit includes: a switch tube S4, a diode D2 and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with the source electrode of the switch tube S3, the drain electrode of the switch tube S3 is also connected with the drain electrode of the switch tube S2 through a capacitor C2, and two ends of the capacitor C2 are respectively connected with two power supply ends of a cell heating film UO 2;

the source electrode of the switching tube S2 is also connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S3 is further connected with the cathode of the diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, and the drain of the switch tube S4 is connected with the other end of the inductor L;

the source of the switch tube S4 is further connected to the cathode of the diode D1, the anode of the diode D1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the drain of the switch tube S4;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

Further, in the present invention, a three-port DC/DC converter includes: a single-input single-output mode and a single-input dual-output mode.

Further, in the invention, when the three-port DC/DC converter is in a single-input single-output mode, the fuel cell independently supplies power for the battery heating film or the driving motor controller UO1 respectively;

in the single-input single-output mode a, the fuel cell independently supplies power to the cell heating membrane;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 and the switch tube S4 are kept on, and the switch tube S3 is kept off;

t_onthe state is as follows: the switching tube S1 is in a conducting state, and the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S1 is also connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with the source of the switch tube S1;

t_offthe state is as follows: the switching tube S1 is in an off state, and the equivalent circuit includes: a switch tube S2, a capacitor C2, an inductor L, a switch tube S4 and a diode D2;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, the drain of the switch tube S4 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of the switch tube S2; two ends of the capacitor C2 are also respectively connected with two power supply ends of the battery heating film UO 2;

in the single-input single-output mode b, the fuel cell independently supplies power to the drive motor controller Uo 1;

the switching tube S1, the switching tube S2 and the switching tube S3 are controlled by the PWM signal, and the switching tube S4 is kept turned off;

t_onthe state is as follows: the switch tube S1 and the switch tube S2 are in a conducting state, the switch tube S3 is in an off state, and the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor;

t_offthe state is as follows: the switch tube S1 and the switch tube S2 are in an off state, the switch tube S3 is in an on state, and the equivalent circuit includes: a switch tube S3, an inductor L, a capacitor C1, a diode D1 and a diode D2;

the source of the switch tube S3 is connected to one end of the inductor L, the other end of the inductor L is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the drain of the switch tube S3, and the two ends of the capacitor C1 are respectively connected to the two power supply ends of the drive motor controller Uo 1.

Further, in the invention, when the three-port DC/DC converter is in a single-input double-output mode, the fuel cell independently supplies power to the battery heating film and the driving motor controller UO1 simultaneously;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 is switched on, and the switch tube S3 and the switch tube S4 are switched off;

t_onin a state where the switching tube S1 is in a conducting state, the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L, a capacitor C2 and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with one end of a capacitor C2;

two ends of the capacitor C1 are respectively connected with two power supply ends of a driving motor controller UO 1;

t_offin the state that the switching tube S1 is in the off state, the equivalent circuit includes: a switch tube S2, an inductor L, a capacitor C2, a diode D1, a diode D2 and a capacitor C1;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of a diode D2 is connected with the cathode of a diode D1, the anode of a diode D1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of a switch tube S2;

two ends of the capacitor C2 are respectively connected with two power supply ends of the battery heating film UO 2;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

Furthermore, in the invention, the converter control circuit comprises a protection circuit, a DSP system, a voltage sensor group, a current sensor group and a temperature sensor;

the voltage sensor group comprises a plurality of voltage sensors which respectively collect the output voltage of the fuel cell Uin, the output voltage of the power cell and the input voltage of the cell heating film UO 2;

the current sensor group comprises a plurality of current sensors which respectively collect the output current of the fuel cell Uin, the output current of the power cell and the input current of the cell heating film UO 2;

the temperature sensor is used for collecting the surface temperature of the power battery; and the acquired temperature signal is sent to a DSP system;

inputting a target voltage at a target voltage signal input end of the DSP system;

a switch tube driving signal output end of the DSP system sends a switch tube driving signal to a signal input end of the three-port DC/DC converter through a protection circuit;

the DSP system judges whether the power battery needs to be heated or not by utilizing the surface temperature of the power battery, calculates the power required by a battery heating film if the power battery needs to be heated, and acquires the power required by the whole vehicle through the whole vehicle controller;

the DSP system also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input single-output mode a when the automobile is not started and the power battery needs to be heated;

the DSP system also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input single-output mode b when the automobile normally runs and the power battery does not need to be heated;

the DSP system also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input double-output mode when the temperature of the automobile is reduced to the warning temperature in the driving process;

and the DSP system also acquires the required power of the whole vehicle, the required power of the battery heating film and the output power of the power battery according to the vehicle controller, adjusts the PWM signal in real time and adjusts the output power of the fuel battery.

The invention adopts an integrated converter to connect three ports of a fuel cell, a cell heating membrane and a driving motor controller UO1, and has the function of unified energy management. Single-stage power conversion is adopted between the input port and the two output ports, and centralized control and higher conversion efficiency can be realized. The converter only comprises two diodes and one inductor, the inductor is shared, and at most only two switching tubes are in a high-frequency switching state in any working mode, so that the converter is low in cost, high in efficiency and simple to control. The problems of high cost, difficulty in coordination control, working reliability and the like of a plurality of two-port converters used in a traditional fuel cell extended-range electric automobile power cell preheating system are solved. When the fuel cell supplies power to the output port of the driving motor controller UO1, the output voltage regulation range is wide, and the adaptability is strong. The three-port DC/DC converter can provide power for normal running of an automobile and power for temperature rise of a power battery at the same time by using a simple structure, and is convenient to integrally control and simple in design.

Drawings

FIG. 1 is an overall structural diagram of a power supply system of a fuel cell extended range hybrid electric vehicle according to the present invention;

FIG. 2 is a topology diagram of a three-port DC/DC converter;

FIG. 3 shows t in a single-input single-output mode a of a three-port DC/DC converter_onEquivalent circuit and energy flow diagrams at state;

FIG. 4 shows t in a single-input single-output mode a of a three-port DC/DC converter_offEquivalent circuit and energy flow diagrams at state;

FIG. 5 shows t in the single-input single-output mode b of the three-port DC/DC converter_onEquivalent circuit and energy flow diagrams at state;

FIG. 6 shows t in the single-input single-output mode b of the three-port DC/DC converter_offEquivalent circuit and energy flow diagrams at state;

FIG. 7 shows t in a dual-input single-output mode of a three-port DC/DC converter_onEquivalent circuit and energy flow diagrams at state;

FIG. 8 shows t in a dual-input single-output mode of a three-port DC/DC converter_offEquivalent circuit and energy flow diagrams at state;

fig. 9 is a block diagram of a three-port DC/DC converter and a control circuit.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

The first embodiment is as follows: the following describes the present embodiment with reference to fig. 1 and fig. 2, the fuel cell extended range hybrid electric vehicle power supply system of the present embodiment includes a three-port DC/DC converter, a power cell, a cell heating membrane Uo2, a fuel cell Uin, and a converter control circuit;

three ports of the three-port DC/DC converter are respectively connected with a power supply end of a battery heating film UO2, a power supply end of a fuel cell and a power supply end of a driving motor controller UO 1;

the converter control circuit is used for controlling the switch of a switch tube in the three-port DC/DC converter to enable the three-port DC/DC converter to be in different working modes;

the battery heating film UO2 is arranged on the outer side of the power battery and used for heating the power battery;

the three-port DC/DC converter includes: a Buck-Boost circuit, a half-bridge structure and an additional circuit;

the Buck-Boost circuit includes: a diode D1, a switch tube S1, an inductor L and a capacitor C1;

the half-bridge structure comprises: a switch tube S2, a switch tube S3;

the additional circuit includes: a switch tube S4, a diode D2 and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with the source electrode of the switch tube S3, the drain electrode of the switch tube S3 is also connected with the drain electrode of the switch tube S2 through a capacitor C2, and two ends of the capacitor C2 are respectively connected with two power supply ends of a cell heating film UO 2;

the source electrode of the switching tube S2 is also connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S3 is further connected with the cathode of the diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, and the drain of the switch tube S4 is connected with the other end of the inductor L;

the source of the switch tube S4 is further connected to the cathode of the diode D1, the anode of the diode D1 is connected to one end of the capacitor C1, and the other end of the capacitor C1 is connected to the drain of the switch tube S4;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

Further, in the present embodiment, description will be made with reference to fig. 3 to 8; the three-port DC/DC converter includes: a single-input single-output mode and a single-input dual-output mode.

Further, in the present embodiment, when the three-port DC/DC converter is in the single-input single-output mode, the fuel cell individually supplies power to the battery heating film Uo2 or the driving motor controller Uo 1;

in the single-input single-output mode a, the fuel cell independently supplies power to the cell heating membrane;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 and the switch tube S4 are kept on, and the switch tube S3 is kept off;

as shown in FIG. 3, t_onThe state is as follows: the switching tube S1 is in a conducting state, and the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L and a capacitor C2;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S1 is also connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with the source of the switch tube S1;

as shown in fig. 4, t_offThe state is as follows: the switching tube S1 is in an off state, and the equivalent circuit includes: a switch tube S2, a capacitor C2, an inductor L, a switch tube S4 and a diode D2;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of the diode D2 is connected with the source of the switch tube S4, the drain of the switch tube S4 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of the switch tube S2; two ends of the capacitor C2 are also respectively connected with two power supply ends of the battery heating film UO 2;

in the single-input single-output mode b, the fuel cell independently supplies power to the drive motor controller Uo 1;

the switching tube S1, the switching tube S2 and the switching tube S3 are controlled by the PWM signal, and the switching tube S4 is kept turned off;

as shown in fig. 5, t_onThe state is as follows: the switch tube S1 and the switch tube S2 are in a conducting state, the switch tube S3 is in an off state, and the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor;

shown in connection with FIG. 6, t_offThe state is as follows: the switch tube S1 and the switch tube S2 are in an off state, the switch tube S3 is in an on state, and the equivalent circuit includes: a switch tube S3, an inductor L, a capacitor C1, a diode D1 and a diode D2;

the source of the switch tube S3 is connected to one end of the inductor L, the other end of the inductor L is connected to one end of the capacitor C1, the other end of the capacitor C1 is connected to the anode of the diode D1, the cathode of the diode D1 is connected to the anode of the diode D2, the cathode of the diode D2 is connected to the drain of the switch tube S3, and the two ends of the capacitor C1 are respectively connected to the two power supply ends of the drive motor controller Uo 1.

Further, in the present embodiment, when the three-port DC/DC converter is in the single-input dual-output mode, the fuel cell independently supplies power to the battery heating film Uo2 and the driving motor controller Uo 1;

the switch tube S1 is controlled by the PWM signal, the switch tube S2 is switched on, and the switch tube S3 and the switch tube S4 are switched off;

as shown in FIG. 7, t_onIn a state where the switching tube S1 is in a conducting state, the equivalent circuit includes: a switch tube S1, a switch tube S2, an inductor L, a capacitor C2 and a capacitor C1;

the drain electrode of the switch tube S1 is connected with the anode of the fuel cell Uin, the source electrode of the switch tube S1 is connected with the drain electrode of the switch tube S2, the source electrode of the switch tube S2 is connected with one end of an inductor L, and the other end of the inductor L is connected with the cathode of the fuel cell Uin;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with one power supply end of a battery heating film UO2, and the other power supply end of the battery heating film UO2 is connected with one end of a capacitor C2;

two ends of the capacitor C1 are respectively connected with two power supply ends of a driving motor controller UO 1;

as shown in fig. 8, t_offIn the state that the switching tube S1 is in the off state, the equivalent circuit includes: a switch tube S2, an inductor L, a capacitor C2, a diode D1, a diode D2 and a capacitor C1;

the drain of the switch tube S2 is connected with one end of a capacitor C2, the other end of the capacitor C2 is connected with the cathode of a diode D2, the anode of a diode D2 is connected with the cathode of a diode D1, the anode of a diode D1 is connected with one end of a capacitor C1, the other end of the capacitor C1 is connected with one end of an inductor L, and the other end of the inductor L is connected with the source of a switch tube S2;

two ends of the capacitor C2 are respectively connected with two power supply ends of the battery heating film UO 2;

two ends of the capacitor C1 are respectively connected with two power supply ends controlled by the motor.

Further, in this embodiment, the converter control circuit includes a protection circuit 201, a DSP system 202, a voltage sensor group 203, a current sensor group 204, and a temperature sensor 205, as described in this embodiment with reference to fig. 9;

the voltage sensor group 203 comprises a plurality of voltage sensors which respectively collect the output voltage of the fuel cell Uin, the output voltage of the power cell and the input voltage of the cell heating film Uo 2;

the current sensor group 204 comprises a plurality of current sensors which respectively collect the output current of the fuel cell Uin, the output current of the power cell and the input current of the cell heating film Uo 2;

the temperature sensor 205 is used for acquiring the surface temperature of the power battery; and sends the collected temperature signal to the DSP system 202;

a target voltage is input to a target voltage signal input end of the DSP system 202;

a switching tube driving signal output end of the DSP system 202 sends a switching tube driving signal to a signal input end of the three-port DC/DC converter through the protection circuit 201;

the DSP system 202 judges whether the power battery needs to be heated or not by using the surface temperature of the power battery, calculates the power required by a battery heating film if the power battery needs to be heated, and acquires the power required by the whole vehicle through the whole vehicle controller;

the DSP system 202 also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input single-output mode a when the automobile is not started and the power battery needs to be heated;

the DSP system 202 also outputs PWM control signals to enable the three-port DC/DC converter to be in a single-input single-output mode b when the automobile runs normally and the power battery does not need to be heated;

the DSP system 202 also outputs a PWM control signal to enable the three-port DC/DC converter to be in a single-input double-output mode when the temperature of the automobile is reduced to the warning temperature in the driving process;

the DSP system 202 also obtains the power required by the whole vehicle, the power required by the battery heating film and the output power of the power battery according to the whole vehicle controller, adjusts the PWM signal in real time and adjusts the output power of the fuel battery.

The DC/DC converter structure and the operation method for realizing low-temperature environment operation of the fuel cell extended range electric automobile have the advantages that the specific multiple ports can integrate the fuel cell, the cell heating membrane port and the output port of the driving motor controller UO1 into a whole, and the functions of low-temperature preheating of the power cell and maintaining the temperature of the power cell in a low-temperature driving environment can be realized while the fuel cell provides normal working power for the driving motor controller UO1 by using a more compact converter structure. Meanwhile, the topological structure in the patent has two working modes of single input and double output and single input and single output;

single input single output mode: when the fuel cell extended range electric vehicle is preheated before starting and operates in the normal operation mode, the fuel cell independently supplies power to the power battery and the driving motor controller Uo1 respectively:

a. the fuel cell only needs to provide required power for the cell heating film, and low-temperature preheating before starting the fuel cell range-extended electric vehicle is realized;

in this mode, the switch tube S1 is controlled by the PWM signal, the switch tube S2 and the switch tube S4 are kept on, and the switch tube S3 is kept off.

When the switch tube S1 is in the conducting state, i.e. ton, the equivalent circuit and the energy flow diagram of the circuit are shown in fig. 3, at this time, the fuel cell output port Uin charges the inductor L through the switch tube S1 and the switch tube S2, the inductor current increases linearly, and at the same time, the capacitor C1 discharges and supplies power to the cell heating film, so as to maintain the voltage current of the cell heating film.

When the switch tube S1 is turned off, i.e., toff, the equivalent circuit and the energy flow diagram of the circuit are shown in fig. 4, and at this time, the inductor L supplies power to the battery heating film and the capacitor C1 through the switch tube S2, the switch tube S4 and the diode D2, and the inductor current linearly decreases.

b. The fuel cell only needs to provide required power for the driving motor controller UO1, and the fuel cell increases the normal driving process of the range electric vehicle after preheating is completed;

in this mode, the switch tube S1, the switch tube S2, and the switch tube S3 are controlled by the PWM signal, and the switch tube S4 remains off.

When the switching tube S1 and the switching tube S2 are in a conducting state and the switching tube S3 is in an off state, that is, ton, the equivalent circuit and the energy flow diagram of the circuit are shown in fig. 5, at this time, the output port Uin of the fuel cell charges the inductor L through the switching tube S1 and the switching tube S2, the inductor current linearly increases, and the capacitor C1 supplies power to the driving motor controller Uo1 to maintain the voltage current of the driving motor controller Uo 1.

When the switch tube S1 and the switch tube S2 are in an off state and the switch tube S3 is in an on state, i.e., toff, the equivalent circuit and the energy flow diagram of the circuit are shown in fig. 6, at this time, the inductor L supplies power to the capacitor C2 and the driving motor through the switch tube S3, the diode D1 and the diode D2, and the inductor current linearly decreases.

Single input dual output mode: when the fuel cell extended range electric automobile normally runs in a low-temperature environment, the temperature of the power cell needs to be detected in real time in order to maintain the normal working performance of the power cell, when the temperature of the power cell is too low, the fuel cell needs to provide power for the driving motor controller Uo1 and simultaneously provide power for the battery heating film, in this mode, the switching tube S1 is controlled by a PWM signal, the switching tube S2 is switched on, and the switching tube S3 and the switching tube S4 are switched off;

when the switching tube S1 is in the conducting state, i.e. ton, the equivalent circuit and the energy flow diagram of the circuit are as shown in fig. 7, at this time, the fuel cell output port Uin charges the inductor L through the switching tube S1 and the switching tube S2, the inductor current increases linearly, and the capacitors C1 and C2 respectively supply power to the driving motor controller Uo1 and the battery heating film.

When the switching tube S1 is in an off state, that is, toff, the equivalent circuit and the energy flow diagram of the circuit are as shown in fig. 8, and at this time, the inductor L supplies power to the capacitor C1 and the driving motor controller Uo1 through the diode D1 and the diode D2, and also supplies power to the battery heating film Uo2 and the parallel capacitor C2 thereof;

the required power is calculated by adopting a formula P as UI, the required power of the whole vehicle is obtained from a whole vehicle controller, and the required power of a battery heating film is obtained from a temperature sensor;

when the fuel cell extended range electric vehicle is started and the power battery is preheated at low temperature, the DSP system outputs a PWM control signal to control the on and off of a corresponding switch tube, so that the system works in a single-input single-output mode a;

for the single-input single-output mode a, the fuel cell only needs to provide the required power for the heating membrane, and the power control principle is that the heat energy required to be provided by the heating membrane is determined according to the mathematical relation between the temperature and the heat quantity of the power cell detected by the temperature sensor, and the heat energy of the heating membrane is derived from the electric energy (W ═ pt) provided by the fuel cell in the three-port converter for the heating membrane, namely the energy required by the heating membrane and consumed by the fuel cell in a certain power level for working for a period of time, and the heating membrane can be approximately equivalent to a constant load; before the extended-range fuel cell automobile is started, if the temperature sensor detects that the temperature of the power cell is too low, the three-port DC/DC converter works in a single-input single-output mode through the DSP system, at the moment, a driving signal sent by the DSP system controls the switch tube S2 and the switch tube S4 to be kept on through the protection circuit, the switch tube S3 is kept off, and a PWM driving signal of the switch tube S1 is subjected to closed-loop PI control according to a voltage signal and a voltage current signal of a Uo2 port collected by the voltage sensor and the current sensor, so that constant power output of a heating film output port Uo2 is realized and lasts for a certain time, and when the temperature sensor detects that a temperature feedback signal of the power cell reaches the normal working temperature, the switch tube is controlled to be turned off through the DSP system, and the single-input single-output mode a is ended.

When the fuel cell extended range electric vehicle runs normally, the DSP system 202 outputs PWM control signals to control the on and off of corresponding switch tubes, so that the system works in a single-input single-output mode b;

for the single-input single-output mode b, the fuel cell only needs to provide required power for the motor controller, the power level required by the extended range fuel cell automobile under different running conditions is obtained from the whole automobile controller, at the moment, a driving signal sent by the DSP system controls the switching tube S4 to be kept off through the protection circuit, then the PWM driving signals of the switching tube S1, the switching tube S2 and the switching tube S4 are carried out in a closed-loop PI mode according to the voltage and current signals of the port of the motor controller UO2 obtained by the voltage and current sensors, so as to realize the specific power output of the output port UO1 of the motor controller, and the voltage and current of the UO2 port are subjected to closed-loop regulation in real time along with the difference of the required power under different working conditions of the extended range fuel cell automobile, so as to realize the purpose of maintaining the specific power output, the port of the driving motor controller can be approximately equivalent to a variable resistance load, when the extended range fuel cell vehicle stops running or the temperature of the power battery is too low, the power control mode is exited through the DSP program.

When the temperature of the power battery is reduced to the warning temperature in the running process of the fuel battery hybrid electric vehicle, the DSP (202) system outputs a PWM control signal to control the on and off of a corresponding switch tube, so that the system works in a single-input double-output mode;

for the single-input double-output mode, the fuel cell needs to provide power for the motor controller and simultaneously provide power for the heating film, at the moment, the power generated by the fuel cell is the sum of the power required by the motor controller and the power required by the heating film, at the moment, the driving signal sent by the DSP system controls the switch tube S2 to be switched on through the protection circuit, the switch tube S3 and the switch tube S4 are switched off, and according to the voltage and current signals transmitted to two ends of a motor controller port UO1 of the DSP by the voltage and current sensors and the voltage and current signals transmitted to two ends of a heating film port UO2, a PWM driving signal of a closed-loop PI control switch tube S1 is carried out, and the working mode is continued for a short time, when the temperature of the power battery detected by the temperature sensor reaches the normal working temperature, the power control mode is exited through the DSP program, and the single-input single-output mode b is entered until the extended-range fuel cell vehicle stops running.

Although the invention herein has been described with reference to particular embodiments, it is to be understood that these embodiments are merely illustrative of the principles and applications of the present invention. It is therefore to be understood that numerous modifications may be made to the illustrative embodiments and that other arrangements may be devised without departing from the spirit and scope of the present invention as defined by the appended claims. It should be understood that features described in different dependent claims and herein may be combined in ways different from those described in the original claims. It is also to be understood that features described in connection with individual embodiments may be used in other described embodiments.