An inverter for a high-speed air compressor of a fuel cell vehicle

Abstract

The invention discloses an inverter for a high-speed air compressor of a fuel cell vehicle, which is used for converting direct current provided by a fuel cell into alternating current for use by the high-speed air compressor, and comprises: an inverter unit, connected between a controllable braking unit and a three-phase power supply; a controllable braking unit, connected between a DC bus and the inverter unit; a feedback sampling unit, connected to two phases of the three-phase power supply, comprising a current sampling module and a temperature sampling module, for collecting current signals and temperature signals of the inverter unit; a control unit, arranged on a control board, connected to the feedback sampling unit and a host computer; a drive unit, connected between the inverter unit and the control unit; a flyback unit, comprising a flyback power supply and a MOS drive, the flyback power supply being used for generating multi-channel voltages, the MOS drive being used for controlling the flyback power supply, the flyback unit being connected to the control board via a connecting terminal, and providing power to the control unit and the drive unit; an electrolytic capacitor; a power board; a shielding board; an off-board capacitor; and a water cooling unit.

Description

Technical Field

[0001] The present invention relates to the field of inverters, and in particular to an inverter for a high-speed air compressor of a fuel cell vehicle. Background Art

[0002] The mainstream power devices used in traditional inverters are made of silicon materials. After nearly 60 years of evolution, silicon-based devices have made great progress, and their device performance has gradually approached the theoretical limit of their materials. However, when used under extreme conditions, problems such as low switching frequency, low efficiency, and low temperature tolerance still occur.

[0003] Due to the high requirements of various components in fuel cell vehicles: the working voltage of the inverter varies between 200V and 700V, the cooling water temperature is as high as 85℃, and the required switching frequency is above 30kHZ. At the same time, in order to apply the fuel cell system to passenger cars, the various requirements for the required air compressor are more stringent: while achieving the specified intake pressure and intake quality, the volume of the air compressor must be reduced, so the air compressor speed needs to be greatly increased. This also puts forward requirements for the switching frequency of the inverter. At the same time, in order to reduce the volume of the entire air compressor, reducing the volume of the inverter through reasonable optimization of the layout is also one of the requirements of the inverter design. Summary of the invention

[0004] The invention provides an inverter for a high-speed air compressor of a fuel cell vehicle, which is used for converting direct current provided by a fuel cell into alternating current used by the high-speed air compressor.

[0005] In order to achieve the above-mentioned object, the inverter for a high-speed air compressor of a fuel cell vehicle provided by the present invention comprises:

[0006] An inverter unit, used to convert direct current into alternating current used by the power supply machine;

[0007] The controllable braking unit is connected between the DC bus and the inverter unit to protect the inverter unit when the motor is abnormal;

[0008] A feedback sampling unit is connected to two phases of the three-phase power supply, and includes a current sampling module and a temperature sampling module, and is used to collect current signals and temperature signals of the inverter unit;

[0009] A control unit is arranged on a control board, connected to the feedback sampling unit and a host computer, and is used to receive commands from the host computer and send control commands, as well as receive current signals and temperature signals of the inverter unit collected by the feedback sampling unit;

[0010] A drive unit, connected between the inverter unit and the control unit, for converting a received control instruction into a drive signal;

[0011] The flyback unit includes a flyback power supply and a MOS driver, wherein the flyback power supply is used to generate multiple voltages, the MOS driver is used to control the flyback power supply, and the flyback unit is connected to the control board through a connecting terminal to provide power to the control unit and the drive unit;

[0012] Electrolytic capacitors, used for filtering and storing electrical energy;

[0013] The power board, the inverter unit, the flyback unit, and the electrolytic capacitor are arranged on the back of the power board, and the electrolytic capacitor is welded on the back of the power board through pins;

[0014] A shielding plate, arranged between the control board and the power board, for isolating signal interference;

[0015] The external capacitor includes multiple capacitors in parallel, which are connected to the power board and the DC bus to eliminate the impact of bus voltage fluctuations;

[0016] The water cooling unit is arranged below the back of the power board, and includes a water cooling plate, on which a first opening and a second opening are provided opposite to each other. The first opening is arranged on a side close to the inverter unit for cooling water to flow in, and the second opening is for cooling water to flow out. The water cooling unit is used to cool down the inverter for the high-speed air compressor of the fuel cell vehicle as a whole.

[0017] The temperature sampling module is arranged between the inverter unit and the electrolytic capacitor, the current sampling module is arranged on one side of the temperature sampling module, and the inverter unit is connected between the controllable braking unit and the three-phase power supply.

[0018] In one embodiment of the present invention, the current sampling module collects two-phase currents.

[0019] In one embodiment of the present invention, the switch tubes in the controllable braking unit, the inverter unit, the control unit and the drive unit are all made of silicon carbide material.

[0020] In one embodiment of the present invention, the controllable braking unit includes a built-in resistor and an external braking resistor. When the braking power of the built-in resistor is insufficient, the controllable braking unit can expand the braking power of the inverter.

[0021] In one embodiment of the present invention, the inverter for a high-speed air compressor of a fuel cell vehicle further includes a housing for accommodating the above-mentioned components.

[0022] In one embodiment of the present invention, a heat sink is provided between the electrolytic capacitor and the water cooling unit, and a contact portion between the electrolytic capacitor and the heat sink is coated with thermal conductive silicone grease.

[0023] The inverter for high-speed air compressor of fuel cell vehicle provided by the utility model adopts silicon carbide semiconductor of wide bandgap material as power conversion device, and has the following advantages compared with traditional inverters: more compact structure, smaller volume, higher heat resistance temperature, high blocking voltage, low loss, and fast switching speed. Combining the above advantages, under the same power level, the number of power devices, the volume of radiator, and the volume of filter elements in the equipment can be greatly reduced, and the efficiency is also greatly improved. At the same time, an optimized structural layout method is adopted to greatly reduce the stray inductance in the whole inverter, and the interference of various components between systems is also reduced accordingly. Through the optimized design of the inverter, the space occupied by the inverter becomes smaller, the heat dissipation is better, the switching frequency that can be provided reaches 30-50kHZ, the corresponding motor speed reaches more than 120,000 revolutions, the efficiency reaches more than 95%, and the speed and the air compressor air pump intake pressure and intake quality all meet the established requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0025] Figure 1 A schematic diagram of the connection of the main components of the inverter for the high-speed air compressor of a fuel cell vehicle provided by the present invention;

[0026] Figure 2 It is a cross-sectional view of the power board;

[0027] Figure 3 This is a side sectional view of the inverter for a high-speed air compressor of a fuel cell vehicle provided by the present invention.

[0028] Explanation of the accompanying drawings: 1-inverter unit; 2-controllable braking unit; 3-feedback sampling unit; 31-current sampling module; 32-temperature sampling module; 4-control unit; B-control board; 5-drive unit; 6-flyback unit; 61-flyback power supply; 62-MOS drive; P-connection terminal; 7-electrolytic capacitor; 8-power board; 9-shielding board; 10-off-board capacitor; 11-water cooling unit; 12-heat sink. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Figure 1 This is a schematic diagram of the connection of the main components of the inverter for the high-speed air compressor of a fuel cell vehicle provided by the present invention. Figure 2 is a cross-sectional view of the power board. Figure 3 A side cross-sectional view of the inverter for a high-speed air compressor of a fuel cell vehicle provided by the present invention, as shown in FIG. Figure 1-Figure 3 As shown, the inverter for a high-speed air compressor of a fuel cell vehicle provided by the present invention comprises:

[0031] Inverter unit 1 is used to convert DC power into AC power for the power supply machine. Its main function is to assist in completing the three-phase output of the inverter. Due to switching losses, it needs to be cooled.

[0032] The controllable braking unit 2 is connected between the DC bus and the inverter unit 1 to protect the inverter unit 1 when an abnormality occurs in the motor;

[0033] The feedback sampling unit 3 is connected to two phases of the three-phase power supply, and includes a current sampling module 31 and a temperature sampling module 32, and is used to collect the current signal and the temperature signal of the inverter unit 1;

[0034] The control unit 4 is arranged on a control board B, connected to the feedback sampling unit 3 and a host computer (not shown in the figure), and is used to receive commands from the host computer and send control commands, as well as receive the current signal and temperature signal of the inverter unit 1 collected by the feedback sampling unit 3;

[0035] The drive unit 5 is connected between the inverter unit 1 and the control unit 4 and is used to convert the received control instruction into a drive signal;

[0036] The flyback unit 6 includes a flyback power supply 61 and a MOS driver 62. The flyback power supply 61 is used to generate multi-channel voltages. The MOS driver 62 is used to control the flyback power supply 61. The flyback unit 6 is connected to the control board B through the connection terminal P to provide power to the control unit 4 and the drive unit 5.

[0037] Electrolytic capacitor 7, used for filtering and storing electric energy;

[0038] The power board 8, the inverter unit 1, the flyback unit 6, and the electrolytic capacitor 7 are arranged on the back of the power board 8 so that these components share the same vertical space to improve space utilization. The electrolytic capacitor 7 is welded on the back of the power board 8 through pins;

[0039] The shielding plate 9 is arranged between the control board B and the power board 8 to isolate signal interference;

[0040] The off-board capacitor 10 includes a plurality of capacitors connected in parallel and is connected to the power board 8 and the DC bus to eliminate the influence of bus voltage fluctuations;

[0041] The water cooling unit 11 is arranged below the back of the power board 8, and includes a water cooling plate. The water cooling plate is provided with a first opening and a second opening opposite to each other. The first opening is arranged on a side close to the inverter unit 1 for cooling water to flow in, and the second opening is for cooling water to flow out. The water cooling unit 11 is used to cool down the inverter for the high-speed air compressor of the fuel cell vehicle as a whole.

[0042] Among them, since the inverter unit 1 is the main source of heat, the temperature sampling module 32 is set between the inverter unit 1 and the electrolytic capacitor, and the current sampling module 31 is set on one side of the temperature sampling module 32, which is relatively spacious and easy to place cables.

[0043] Figure 2 U, V, and W are power terminals, on which are welded patch nuts to facilitate cable installation.

[0044] In this embodiment, under the premise of not affecting the efficiency and control effect, the current sampling module 31 only collects two-phase currents.

[0045] The switch tubes in the controllable brake unit 2, the inverter unit 1, the control unit 4 and the drive unit 5 are all made of silicon carbide material, so that the inverter can achieve the purposes of high switching frequency, high temperature resistance, high power density, and anti-electromagnetic radiation.

[0046] The controllable braking unit 2 includes a built-in resistor and an external braking resistor. When the braking power of the built-in resistor is insufficient, the controllable braking unit can expand the braking power of the inverter.

[0047] The inverter for a high-speed air compressor of a fuel cell vehicle provided by the present invention further includes a housing for accommodating the above-mentioned components and protecting the internal components.

[0048] A heat sink 12 is provided between the electrolytic capacitor 7 and the water cooling unit 11 to compensate for the problem of insufficient height of the electrolytic capacitor 7. The contact portion between the electrolytic capacitor 7 and the heat sink 12 is coated with thermal grease or other thermal conductive medium to facilitate heat conduction between the electrolytic capacitor 7 and the water cooling unit 11. In addition, in the present invention, the MOS driver 62 that is prone to heat is placed on the water cooling unit 11 in the form of a separate module and is connected to the power board 8 through the connection terminal P.

[0049] The inverter for high-speed air compressor of fuel cell vehicle provided by the utility model adopts silicon carbide semiconductor of wide bandgap material as power conversion device, and has the following advantages compared with traditional inverters: more compact structure, smaller volume, higher heat resistance temperature, high blocking voltage, low loss, and fast switching speed. Combining the above advantages, under the same power level, the number of power devices, the volume of radiator, and the volume of filter elements in the equipment can be greatly reduced, and the efficiency is also greatly improved. At the same time, an optimized structural layout method is adopted to greatly reduce the stray inductance in the whole inverter, and the interference of various components between systems is also reduced accordingly. Through the optimized design of the inverter, the space occupied by the inverter becomes smaller, the heat dissipation is better, the switching frequency that can be provided reaches 30-50kHZ, the corresponding motor speed reaches more than 120,000 revolutions, the efficiency reaches more than 95%, and the speed and the air compressor air pump intake pressure and intake quality all meet the established requirements.

[0050] Those skilled in the art can understand that the accompanying drawings are only schematic diagrams of an embodiment, and the modules or processes in the accompanying drawings are not necessarily required to implement the present invention.

[0051] Those skilled in the art can understand that the modules in the device in the embodiment can be distributed in the device in the embodiment according to the description of the embodiment, or can be changed accordingly and located in one or more devices different from the embodiment. The modules in the above embodiment can be combined into one module, or can be further divided into multiple sub-modules.

[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An inverter for a high-speed air compressor of a fuel cell vehicle, which is used to convert the direct current provided by the fuel cell into alternating current for use by the high-speed air compressor, characterized in that: include: An inverter unit, used to convert direct current into alternating current used by the power supply machine; A controllable braking unit is connected between the DC bus and the inverter unit to protect the inverter unit when an abnormality occurs in the motor. The controllable braking unit includes a built-in resistor and an external braking resistor. When the braking power of the built-in resistor is insufficient, the controllable braking unit can expand the braking power of the inverter. A feedback sampling unit is connected to two phases of the three-phase power supply, and includes a current sampling module and a temperature sampling module, and is used to collect current signals and temperature signals of the inverter unit, wherein the current sampling module collects two-phase currents; A control unit is arranged on a control board, connected to the feedback sampling unit and a host computer, and is used to receive commands from the host computer and send control commands, as well as receive current signals and temperature signals of the inverter unit collected by the feedback sampling unit; A drive unit, connected between the inverter unit and the control unit, for converting a received control instruction into a drive signal; The flyback unit includes a flyback power supply and a MOS driver, wherein the flyback power supply is used to generate multiple voltages, the MOS driver is used to control the flyback power supply, and the flyback unit is connected to the control board through a connecting terminal to provide power to the control unit and the drive unit; Electrolytic capacitors, used for filtering and storing electrical energy; The power board, the inverter unit, the flyback unit, and the electrolytic capacitor are arranged on the back of the power board, and the electrolytic capacitor is welded on the back of the power board through pins; A shielding plate, arranged between the control board and the power board, for isolating signal interference; The external capacitor includes multiple capacitors in parallel, which are connected to the power board and the DC bus to eliminate the impact of bus voltage fluctuations; The water cooling unit is arranged below the back of the power board, and includes a water cooling plate, on which a first opening and a second opening are provided opposite to each other. The first opening is arranged on a side close to the inverter unit for cooling water to flow in, and the second opening is for cooling water to flow out. The water cooling unit is used to cool down the inverter for the high-speed air compressor of the fuel cell vehicle as a whole. The temperature sampling module is arranged between the inverter unit and the electrolytic capacitor, the current sampling module is arranged on one side of the temperature sampling module, and the inverter unit is connected between the controllable braking unit and the three-phase power supply.

2. The inverter for a high-speed air compressor of a fuel cell vehicle according to claim 1, characterized in that: The switch tubes in the controllable braking unit, inverter unit, control unit and drive unit are all made of silicon carbide material.

3. The inverter for a high-speed air compressor of a fuel cell vehicle according to claim 1, characterized in that: The invention also comprises a housing for accommodating the components in claim 1.

4. The inverter for a high-speed air compressor of a fuel cell vehicle according to claim 1, characterized in that: A heat sink is provided between the electrolytic capacitor and the water cooling unit, and the contact portion between the electrolytic capacitor and the heat sink is coated with thermal conductive silicone grease.

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