High-voltage power distribution system of electric forklift

Abstract

The invention discloses a high-voltage power distribution system of an electric forklift, and relates to the field of power distribution, a battery interface, a main positive relay, a main negative relay, a pre-charging relay and a pre-charging resistor are arranged in the high-voltage power distribution system of the electric forklift, and on-off of the main positive relay, the main negative relay and the pre-charging relay is uniformly controlled by a VCU. Namely, the power supply process of the OBC or DCDC module to the battery box is controlled by the VCU. According to the scheme, the main positive relay and the main negative relay in the battery box body are independent, the size of the battery box is reduced, the space utilization rate of the power battery system is further increased, and when the main positive relay and the main negative relay break down, a cover plate of the battery box body does not need to be disassembled, so that the sealing protection performance of the power battery system is improved. In addition, according to the scheme, the pre-charging relay and the pre-charging resistor are arranged, the capacitive load is pre-charged at the initial stage of high-voltage power-on, and the phenomenon of relay adhesion caused by overlarge current is avoided.

Description

Technical Field

[0001] The invention relates to a high-voltage power distribution system for an electric forklift, and in particular to the field of power distribution. Background Art

[0002] For the power battery system of an electric forklift, power cells, relays and other components are integrated in the battery box of the power battery system. The power cells are relatively regular in shape and are generally arranged at the bottom of the battery box, occupying a large part of the space. Relays and other components occupy a small part of the space and are generally arranged at the top of the battery box. However, due to the consideration of the processability and protection of the entire box, more space is generally reserved for relays and other components, resulting in low space utilization of the entire power battery system. Moreover, when the relay fails, the battery box cover needs to be disassembled, and disassembly will cause the sealing protection of the entire power battery system to fail to meet the requirements. Summary of the invention

[0003] The purpose of the present invention is to provide a high-voltage power distribution system for electric forklifts. This solution separates the main positive relay and the main negative relay in the battery box, reduces the volume of the battery box, and thus increases the space utilization of the power battery system. When the main positive relay and the main negative relay fail, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system. In addition, this solution pre-charges the capacitive load in the early stage of high-voltage power-on by setting a pre-charge relay and a pre-charge resistor to avoid the occurrence of relay adhesion due to excessive current.

[0004] In order to solve the above technical problems, the present invention provides a high-voltage power distribution system for an electric forklift, comprising: a battery interface, a main positive relay, a main negative relay, a pre-charge relay, and a pre-charge resistor;

[0005] The positive output end of the battery interface is connected to the positive electrode of the battery box, and the negative output end is connected to the negative electrode of the battery box;

[0006] The first end of the contact of the main positive relay is connected to the positive input terminal of the battery interface, the second end of the contact is respectively connected to the positive output terminal of the OBC and the positive input terminal of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0007] The first end of the contact of the main negative relay is connected to the negative input end of the battery interface, the second end of the contact is respectively connected to the negative output end of the OBC and the negative input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0008] The first end of the contact of the pre-charging relay is connected to the first end of the pre-charging resistor, the second end of the contact is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0009] The second end of the pre-charging resistor is connected to the positive input end of the battery interface.

[0010] Optionally, it also includes: the OBC, the DCDC module, an AC charging interface, a DCDC output interface, a positive copper busbar, and a negative copper busbar;

[0011] The positive output end of the OBC module is connected to the first end of the positive copper busbar, the negative output end is connected to the first end of the negative copper busbar, the positive input end is connected to the positive output end of the AC charging interface, and the negative input end is connected to the negative output end of the AC charging interface;

[0012] The second end of the positive copper bar is respectively connected to the positive input end of the DCDC module, the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay;

[0013] The second end of the negative copper busbar is respectively connected to the negative input end of the DCDC module and the second end of the contact of the main negative relay;

[0014] The positive output terminal of the DCDC module is connected to the positive input terminal of the DCDC output interface, and the negative output terminal is connected to the negative input terminal of the DCDC output interface;

[0015] The positive input terminal of the AC charging interface is connected to the positive pole of the AC charging seat;

[0016] The negative input terminal of the AC charging interface is connected to the negative pole of the AC charging seat.

[0017] Optionally, also include:

[0018] A protection device, wherein the first end of the protection device is respectively connected to the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay, and the second end is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, and is used for disconnecting when an overcurrent or overvoltage condition occurs on the output circuit of the OBC and / or the input circuit of the DCDC module.

[0019] Optionally, the protection device is a main fuse, the first end of the main fuse is respectively connected to the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay, and the second end is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, and is used for disconnecting when an overcurrent or overvoltage condition occurs in the output circuit of the OBC and / or the input circuit of the DCDC module.

[0020] Optionally, it also includes: DC fast charging interface, DC fast charging positive relay, DC fast charging negative relay;

[0021] The positive input terminal of the DC fast charging interface is connected to the positive output terminal of the DC fast charging device, and the negative input terminal is connected to the negative output terminal of the DC fast charging device;

[0022] The first end of the contact of the DC fast charging positive relay is connected to the positive output end of the DC fast charging interface, the second end of the contact is respectively connected to the moving contact of the normally open contact of the main positive relay, the second end of the pre-charging resistor and the positive input end of the battery interface, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0023] The first end of the contact of the DC fast charging negative relay is connected to the negative output end of the DC fast charging interface, the second end of the contact is respectively connected to the static contact of the normally open contact of the main negative relay, the negative output end of the OBC and the negative input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground.

[0024] Optionally, also include:

[0025] An internal acquisition module, wherein the acquisition end of the internal acquisition module is respectively connected to the main positive relay, the main negative relay, the pre-charging relay, the DC fast charging positive relay, the DC fast charging negative relay, the positive output end of the OBC, the positive input end of the DCDC module, the negative output end of the OBC and the negative input end of the DCDC module, and the output end is connected to the VCU, for transmitting the collected relay states corresponding to the main positive relay, the main negative relay, the DC fast charging positive relay, the DC fast charging negative relay and the pre-charging relay and the insulation resistance between the output circuit of the OBC and the input circuit of the DCDC module to the VCU.

[0026] Optionally, it also includes: a first MCU interface, a second MCU interface, a third MCU interface and an MCU interface baffle;

[0027] The positive input end of the first MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay;

[0028] The positive input end of the second MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay;

[0029] The positive input end of the third MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay;

[0030] The MCU interface baffle is used to block the first MCU interface, the second MCU interface, or the third MCU interface based on the control of the VCU.

[0031] Optional, also includes: air conditioning heater high pressure interface, water cooling unit high pressure interface;

[0032] The first positive input terminal and the second positive input terminal of the air conditioning heater high-voltage interface are respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output terminal of the OBC and the positive input terminal of the DCDC module, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay;

[0033] The first positive input terminal and the second positive input terminal of the high-pressure interface of the water-cooling unit are respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charging relay, the positive output terminal of the OBC and the positive input terminal of the DCDC module, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay.

[0034] Optionally, it also includes: a first air conditioner heater high-voltage relay, a second air conditioner heater high-voltage relay, a first water cooling unit high-voltage relay, a second water cooling unit high-voltage relay, a first air conditioner heater high-voltage fuse, a second air conditioner heater high-voltage fuse, a first water cooling unit high-voltage fuse, and a second water cooling unit high-voltage fuse;

[0035] A first end of the first air conditioning heater high-voltage fuse is connected to a first positive input end of the air conditioning heater high-voltage interface, and a second end is connected to a static contact of a normally open contact of the first air conditioning heater high-voltage relay;

[0036] The first end of the contact of the first air conditioning heater high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module;

[0037] A first end of the second air conditioning heater high-voltage fuse is connected to the second positive input end of the air conditioning heater high-voltage interface, and a second end is connected to the second end of the contact of the second air conditioning heater high-voltage relay;

[0038] The first end of the contact of the second air conditioning heater high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module;

[0039] A first end of the first water-cooling unit high-voltage fuse is connected to a first positive input end of the water-cooling unit high-voltage interface, and a second end is connected to a second end of a contact of the first water-cooling unit high-voltage relay;

[0040] The first end of the contact of the first water-cooling unit high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module;

[0041] A first end of the second water-cooling unit high-voltage fuse is connected to the second positive input end of the water-cooling unit high-voltage interface, and a second end is connected to the second end of the contact of the second water-cooling unit high-voltage relay;

[0042] The first end of the contact of the second water-cooling unit high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charging relay, the positive output end of the OBC and the positive input end of the DCDC module.

[0043] Optionally, it also includes: a current sensor and an MSD;

[0044] The current sensor passes through the negative input terminal of the battery interface, and the output terminal is connected to the BMS, so as to collect the total current value passing through the battery and transmit the total current value to the BMS;

[0045] The first end of the MSD is connected to the positive input end of the battery interface, and the second end is respectively connected to the first end of the contact of the main positive relay and the second end of the pre-charging resistor.

[0046] The purpose of the present invention is to provide a high-voltage power distribution system for an electric forklift, in which a battery interface, a main positive relay, a main negative relay, a pre-charge relay and a pre-charge resistor are provided, wherein the opening and closing of the main positive relay, the main negative relay and the pre-charge relay are uniformly controlled by the VCU, that is, the power supply process of the OBC or DCDC module to the battery box is controlled by the VCU. This solution separates the main positive relay and the main negative relay in the battery box, reduces the volume of the battery box, and thus increases the space utilization of the power battery system, and when the main positive relay and the main negative relay fail, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system. In addition, this solution pre-charges the capacitive load in the early stage of high-voltage power-on by providing a pre-charge relay and a pre-charge resistor, thereby avoiding the occurrence of relay adhesion due to excessive current. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] 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 embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying creative work.

[0048] Figure 1 A schematic structural diagram of a high-voltage power distribution system for an electric forklift provided by the present invention;

[0049] Figure 2 A schematic structural diagram of another high-voltage power distribution system for an electric forklift provided by the present invention;

[0050] Figure 3 A schematic diagram of the appearance of a high-voltage power distribution system for an electric forklift provided by the present invention;

[0051] Figure 4 A schematic diagram of the appearance of another high-voltage power distribution system for an electric forklift provided by the present invention;

[0052] Figure 5 A schematic diagram of the appearance of another high-voltage power distribution system for an electric forklift provided by the present invention;

[0053] Figure 6 A schematic diagram of power distribution for a whole vehicle provided by the present invention. DETAILED DESCRIPTION

[0054] The core of the present invention is to provide a high-voltage power distribution system for electric forklifts. This solution separates the main positive relay and the main negative relay in the battery box, reduces the volume of the battery box, and thus increases the space utilization of the power battery system. When the main positive relay and the main negative relay fail, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system. In addition, this solution pre-charges the capacitive load in the early stage of high-voltage power-on by setting a pre-charge relay and a pre-charge resistor to avoid the occurrence of relay adhesion due to excessive current.

[0055] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are 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.

[0056] Please refer to Figure 1 , Figure 1 The schematic diagram of the structure of a high-voltage power distribution system for an electric forklift provided by the present invention. The high-voltage power distribution system for an electric forklift comprises: a battery interface 1, a main positive relay 2, a main negative relay 3, a pre-charge relay 4, and a pre-charge resistor 5;

[0057] The positive output terminal of the battery interface 1 is connected to the positive pole of the battery box, and the negative output terminal is connected to the negative pole of the battery box;

[0058] The first end of the contact of the main positive relay 2 is connected to the positive input end of the battery interface 1, the second end of the contact is respectively connected to the positive output end of the OBC 6 and the positive input end of the DCDC module 7, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0059] The first end of the contact of the main negative relay 3 is connected to the negative input end of the battery interface 1, the second end of the contact is respectively connected to the negative output end of the OBC 6 and the negative input end of the DCDC module 7, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0060] The first end of the contact of the pre-charging relay 4 is connected to the first end of the pre-charging resistor 5, the second end of the contact is respectively connected to the positive output end of the OBC 6 and the positive input end of the DCDC module 7, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0061] The second end of the pre-charging resistor 5 is connected to the positive input end of the battery interface 1 .

[0062] In the present invention, considering that setting a relay in the battery box will not only reduce the space utilization of the power battery system, but also affect the sealing protection of the power battery system when the relay fails, the main positive relay 2 and the main negative relay 3 in the battery box are separated in this scheme, and a battery interface 1 is set to ensure that the OBC (On-Board Charger) 6 can charge the battery box through the battery interface 1 and the battery box can discharge to the DCDC (Direct Current-Direct Current) module 7 through the battery interface 1. This design reduces the volume of each battery box, thereby increasing the space utilization of the power battery system, and when the main positive relay 2 and the main negative relay 3 fail, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system. In addition, considering that the existing electric forklifts are prone to inrush current at the initial stage of charging due to the capacitor included in their internal controllers, the present solution sets a pre-charge relay 4 and a pre-charge resistor 5. The pre-charge relay 4 is controlled to close by the VCU (Vehicle Control Unit) before the capacitive load is charged, and the initial charging current is limited by the pre-charge resistor 5, that is, the capacitive load is pre-charged to avoid the occurrence of relay sticking due to excessive current.

[0063] It should be noted that this solution, through an integrated design, brings together the high-voltage fuses and high-voltage relays of the entire vehicle, making it easier to maintain the high-voltage circuit of the entire vehicle. The high-voltage power distribution system of an electric forklift is relatively small in size, so disassembling the upper cover for maintenance is not likely to affect its overall sealing.

[0064] It should also be noted that the key point of this solution to reduce the internal volume of the battery box is to separate the main positive relay 2, the main negative relay 3, the pre-charge relay 4, the DC fast charge positive relay 14, the DC fast charge negative relay 15 and the copper busbar connected thereto, and integrate them with other equipment, thereby simplifying the internal structure of the battery box and greatly improving the space utilization. In addition, the main circuit relay in the original PDU can be simplified, reducing the number of high-current relays in the vehicle by one, thereby improving the integration of the vehicle.

[0065] The present embodiment provides a high-voltage power distribution system for an electric forklift, in which a battery interface 1, a main positive relay 2, a main negative relay 3, a pre-charge relay 4 and a pre-charge resistor 5 are provided, wherein the main positive relay 2, the main negative relay 3 and the pre-charge relay 4 are opened and closed by the VCU, that is, the charging process of the OBC6 to the battery box and the discharging process of the battery box to the DCDC module 7 are all controlled by the VCU. The present solution separates the main positive relay 2 and the main negative relay 3 in the battery box, reduces the volume of the battery box, and thus increases the space utilization of the power battery system, and when the main positive relay 2 and the main negative relay 3 fail, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system. In addition, the present solution pre-charges the capacitive load at the initial stage of high-voltage power-on by providing the pre-charge relay 4 and the pre-charge resistor 5, thereby avoiding the occurrence of relay adhesion due to excessive current.

[0066] Based on the above embodiments:

[0067] As an optional embodiment, it also includes: OBC6, DCDC module 7, AC charging interface 8, DCDC output interface 9, positive copper bus 10, negative copper bus 11;

[0068] The positive output terminal of the OBC6 module is connected to the first end of the positive copper busbar 10, the negative output terminal is connected to the first end of the negative copper busbar 11, the positive input terminal is connected to the positive output terminal of the AC charging interface 8, and the negative input terminal is connected to the negative output terminal of the AC charging interface 8;

[0069] The second end of the positive copper busbar 10 is respectively connected to the positive input end of the DCDC module 7, the first end of the contact of the main positive relay 2 and the second end of the contact of the pre-charge relay 4;

[0070] The second end of the negative copper busbar 11 is connected to the negative input end of the DCDC module 7 and the second end of the contact of the main negative relay 3 respectively;

[0071] The positive output terminal of the DCDC module 7 is connected to the positive input terminal of the DCDC output interface 9, and the negative output terminal is connected to the negative input terminal of the DCDC output interface 9;

[0072] The positive input terminal of the AC charging interface 8 is connected to the positive pole of the AC charging socket;

[0073] The negative input terminal of the AC charging interface 8 is connected to the negative pole of the AC charging socket.

[0074] In the present invention, considering that the battery disconnect unit (BDU), power distribution unit (PDU), DCDC module 7 and on-board charger OBC6 in the battery system of the electric forklift are independent of each other, high-voltage cables are required to connect the power distribution unit and the DCDC module 7, and between the power distribution unit and the on-board charger, which not only occupies a large space in the vehicle, but also is more troublesome to install. Therefore, the present solution sets a positive copper busbar 10 and a negative copper busbar 11, and connects OBC6 and DCDC module 7 through the positive copper busbar 10 and the negative copper busbar 11. The present solution also integrates OBC6, DCDC module 7, AC charging interface 8 and DCDC output interface 9 in the high-voltage power distribution system of the electric forklift, that is, OBC6 and PDU, DCDC module 7 and PDU are interconnected through battery interface 1, wherein the AC charging interface 8 is connected to AC power, and corresponding rectification and other operations are performed through OBC6, and the generated DC power is transmitted to the battery box through battery interface 1; the DCDC output interface 9 is connected to the DCDC module 7, and is used to transmit DC power to the DCDC module 7, and then after the voltage transformation operation of the DCDC module 7, the generated DC power is transmitted to the battery box through the battery interface 1, without the need to use high-voltage cables, which greatly reduces the space in the vehicle and reduces the complexity of installation.

[0075] As an optional embodiment, it also includes:

[0076] A protection device 12, wherein the first end of the protection device 12 is respectively connected to the second end of the contact of the main positive relay 2 and the second end of the contact of the pre-charge relay 4, and the second end is respectively connected to the positive output end of the OBC6 and the positive input end of the DCDC module 7, and is used for disconnecting when an overcurrent or overvoltage condition occurs in the output circuit of the OBC6 and / or the input circuit of the DCDC module 7.

[0077] In the present invention, considering that a protective device 12 needs to be installed inside the high-voltage power distribution system of the electric forklift to protect the high-voltage power distribution system of the electric forklift when overcurrent or overvoltage occurs in the power supply circuit, the present solution adds a protective device 12, and utilizes the characteristic of the protective device 12 that actively disconnects when overcurrent or overvoltage occurs in the circuit, thereby improving the safety of the solution.

[0078] As an optional embodiment, the protection device 12 is a main fuse, the first end of the main fuse is respectively connected to the second end of the contact of the main positive relay 2 and the second end of the contact of the pre-charge relay 4, and the second end is respectively connected to the positive output end of OBC6 and the positive input end of the DCDC module 7, and is used for disconnecting when an overcurrent or overvoltage condition occurs in the output circuit of OBC6 and / or the input circuit of the DCDC module 7.

[0079] In the present invention, considering the advantages of fuses such as small size, fast melting speed and low cost, the present solution adopts fuses as protection devices 12, and utilizes the characteristic of fuses that they are actively disconnected when overcurrent or overvoltage occurs in the circuit, thereby improving the safety of the solution. Moreover, because the fuses are separated from the inside of the battery box, the volume of each battery box is also reduced, thereby increasing the space utilization of the power battery system. Moreover, when the fuse fails, there is no need to disassemble the cover of the battery box, thereby improving the sealing protection of the power battery system.

[0080] As an optional embodiment, it also includes: a DC fast charging interface 13, a DC fast charging positive relay 14, and a DC fast charging negative relay 15;

[0081] The positive output terminal of the DC fast charging interface 13 is connected to the positive input terminal of the DC fast charging device, and the negative input terminal is connected to the negative output terminal of the DC fast charging device;

[0082] The first end of the contact of the DC fast charging positive relay 14 is connected to the positive output end of the DC fast charging interface 13, and the second end of the contact is respectively connected to the moving contact of the normally open contact of the main positive relay, the second end of the pre-charging resistor 5 and the positive input end of the battery interface 1, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground;

[0083] The first end of the contact of the DC fast charging negative relay 15 is connected to the negative output end of the DC fast charging interface 13, and the second end of the contact is respectively connected to the static contact of the normally open contact of the main negative relay 3, the negative output end of OBC6 and the negative input end of the DCDC module 7. The first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground.

[0084] In the present invention, considering that the battery box sometimes needs to be charged with DC fast to improve the charging efficiency, in order to save the volume inside the vehicle, this solution also integrates a DC fast charging interface 13, a DC fast charging positive relay 14, and a DC fast charging negative relay 15 in the high-voltage power distribution system of the electric forklift, wherein the DC fast charging positive relay 14 and the DC fast charging negative relay 15 are uniformly controlled by the VCU. When the DC fast charging positive relay 14 and the DC fast charging negative relay 15 are both closed, an external high-power charger can charge the battery box through the DC fast charging interface 13, which not only ensures the control accuracy of the DC fast charging process, but also reduces the space inside the vehicle.

[0085] As an optional embodiment, it also includes:

[0086] The internal acquisition module 16, the acquisition end of the internal acquisition module 16 is respectively connected to the main positive relay 2, the main negative relay 3, the pre-charge relay 4, the DC fast charge positive relay 14, the DC fast charge negative relay 15, the positive output end of OBC6, the positive input end of the DCDC module 7, the negative output end of OBC6 and the negative input end of the DCDC module 7, and the output end is connected to the VCU, which is used to transmit the collected relay states corresponding to the main positive relay 2, the main negative relay 3, the pre-charge relay 4, the DC fast charge positive relay 14, the DC fast charge negative relay 15 and the insulation resistance between the output circuit of OBC6 and the input circuit of the DCDC module 7 to the VCU.

[0087] In the present invention, considering that multiple relays, OBC6 and DCDC module 7 are integrated inside the high-voltage power distribution system of the electric forklift, each relay and the corresponding high-voltage power supply circuit are prone to failure during the actual charging process. Therefore, in order to ensure the safety of the high-voltage power distribution system of the electric forklift, this scheme also provides an internal acquisition module 16, and the internal acquisition module 16 collects the relay states corresponding to the main positive relay 2, the main negative relay 3, the pre-charging relay 4, the DC fast charging positive relay 14, and the DC fast charging negative relay 15, and the positive and negative insulation resistance values ​​of the high-voltage main circuit corresponding to the output circuit of OBC6 and the input circuit of the DCDC module 7, and transmits the above-mentioned relay states and the positive and negative insulation resistance values ​​of the high-voltage main circuit to the VCU, which makes a fault judgment and promptly issues a corresponding alarm so that the user or maintenance personnel can perform repairs according to the fault situation, thereby improving the safety of the scheme.

[0088] As an optional embodiment, it further includes: a first MCU interface 17, a second MCU interface 18, a third MCU interface 19 and an MCU interface baffle 20;

[0089] The positive input terminal of the first MCU interface 17 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output terminal of the OBC 6 and the positive input terminal of the DCDC module 7, and the negative input terminal is connected to the second end of the contact of the main negative relay 3;

[0090] The positive input terminal of the second MCU interface 18 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output terminal of the OBC 6 and the positive input terminal of the DCDC module 7, and the negative input terminal is connected to the second end of the contact of the main negative relay 3;

[0091] The positive input terminal of the third MCU interface 19 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output terminal of the OBC 6 and the positive input terminal of the DCDC module 7, and the negative input terminal is connected to the second end of the contact of the main negative relay 3;

[0092] The MCU interface baffle 20 is used to block the first MCU interface 17 or the second MCU interface 18 or the third MCU interface 19 based on the control of the VCU.

[0093] In the present invention, considering that electric forklift models are divided into two-motor models and three-motor models, if the existing method is followed, PDU is required to distribute power to these two models, but for PDU, because the number of MCU (Motor Controller Unit) interfaces required by the two-motor model and the three-motor model is different, they cannot be universal, which increases the product development cost. Therefore, in order to ensure that the high-voltage power distribution system can supply power to both the two-motor model and the three-motor model, the first MCU interface 17, the second MCU interface 18, the third MCU interface 19 and the MCU interface baffle 20 are set in this scheme. Among them, when the two-motor model needs power supply, any two MCU interfaces of the first MCU interface 17, the second MCU interface 18, and the third MCU interface 19 can be selected to connect the two-motor model according to the charging interface arrangement of the two-motor model; similarly, when the three-motor model needs power supply, the first MCU interface 17, the second MCU interface 18, and the third MCU interface 19 are simultaneously connected to the three-motor model. This scheme adopts a modular design concept, while sharing most of the parts, it realizes the switching between two MCU interfaces and three MCU interfaces, reducing the development cost.

[0094] As an optional embodiment, it also includes: an air conditioning heater high pressure interface 21, a water cooling unit high pressure interface 22;

[0095] The first positive input terminal and the second positive input terminal of the air conditioning heater high-voltage interface 21 are respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output terminal of the OBC6 and the positive input terminal of the DCDC module 7, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay 3;

[0096] The first positive input terminal and the second positive input terminal of the water-cooling unit high-pressure interface 22 are respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charging relay 4, the positive output terminal of OBC6 and the positive input terminal of the DCDC module 7, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay 3.

[0097] In the present invention, considering that there are air-conditioning heater and water-cooling unit in the electric forklift, it is convenient for the actual control of VCU. Therefore, this scheme integrates the air-conditioning heater high-voltage interface 21 and the water-cooling unit high-voltage interface 22 into the electric forklift high-voltage power distribution system, which makes it easier for VCU to control the power supply process of the air-conditioning heater and water-cooling unit and the conduction and shutdown of the remaining relays in the electric forklift high-voltage power distribution system, thereby improving the efficiency of the actual control process.

[0098] As an optional embodiment, it also includes: a first air conditioning heater high-voltage relay 23, a second air conditioning heater high-voltage relay 24, a first water cooling unit high-voltage relay 25, a second water cooling unit high-voltage relay 26, a first air conditioning heater high-voltage fuse 27, a second air conditioning heater high-voltage fuse 28, a first water cooling unit high-voltage fuse 29, and a second water cooling unit high-voltage fuse 30;

[0099] A first end of the first air conditioning and heating high-voltage fuse 27 is connected to the first positive input end of the air conditioning and heating high-voltage interface 21, and a second end is connected to the static contact of the normally open contact of the first air conditioning and heating high-voltage relay 23;

[0100] The first end of the contact of the first air conditioning heater high-voltage relay 23 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output end of the OBC 6 and the positive input end of the DCDC module 7;

[0101] A first end of the second air conditioning and heating high-voltage fuse 28 is connected to the second positive input end of the air conditioning and heating high-voltage interface 21, and a second end is connected to the second end of the contact of the second air conditioning and heating high-voltage relay 24;

[0102] The first end of the contact of the second air conditioning heater high-voltage relay 24 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output end of the OBC 6 and the positive input end of the DCDC module 7;

[0103] A first end of the first water-cooling unit high-voltage fuse 29 is connected to a first positive input end of the water-cooling unit high-voltage interface 22, and a second end is connected to a second end of a contact of the first water-cooling unit high-voltage relay 25;

[0104] The first end of the contact of the first water-cooling unit high-voltage relay 25 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output end of the OBC6 and the positive input end of the DCDC module 7;

[0105] A first end of the second water-cooling unit high-voltage fuse 30 is connected to the second positive input end of the water-cooling unit high-voltage interface 22, and a second end is connected to the second end of the contact of the second water-cooling unit high-voltage relay 26;

[0106] The first end of the contact of the second water cooling unit high-voltage relay 26 is respectively connected to the second end of the contact of the main positive relay 2, the second end of the contact of the pre-charge relay 4, the positive output end of the OBC6 and the positive input end of the DCDC module 7.

[0107] In the present invention, considering that the high-voltage power distribution system of the electric forklift is prone to overvoltage or overcurrent during the actual power distribution process to the air conditioner, heater and wind turbine, and whether the high-voltage power distribution system of the electric forklift distributes power to the air conditioner, heater and wind turbine after being connected to the air conditioner, heater and wind turbine also requires the control of the VCU, so this scheme integrates the first air conditioner and heater high-voltage relay 23, the second air conditioner and heater high-voltage relay 24, the first water cooling unit high-voltage relay 25, the second water cooling unit high-voltage relay 26, the first air conditioner and heater high-voltage fuse 27, the second air conditioner and heater high-voltage fuse 28, the first water cooling unit high-voltage fuse 29, and the second water cooling unit high-voltage fuse 30 in the high-voltage power distribution system of the electric forklift, and actually controls whether the high-voltage power distribution system of the electric forklift distributes power to the air conditioner, heater and wind turbine through the corresponding relays, and ensures that when each circuit has a process or overcurrent situation, the fault circuit can be disconnected in time through the corresponding fuses, so as to ensure the safety of the internal components of the high-voltage power distribution system of the electric forklift, the air conditioner and heater and the wind turbine.

[0108] As an optional embodiment, it further includes: a current sensor 31 and an MSD 32;

[0109] The current sensor 31 passes through the negative input terminal of the battery interface 1, and the output terminal is connected to the BMS, so as to collect the total current value passing through the battery and transmit the total current value to the BMS;

[0110] The first end of MSD32 is connected to the positive input end of the battery interface 1, the second end is respectively connected to the first end of the contact of the main positive relay 2 and the second end of the pre-charging resistor 5, and the control end is connected to the VCU.

[0111] In the present invention, considering that the high-voltage power distribution system of the electric forklift may have an overcurrent during the power distribution process, a current sensor 31 is added in the present solution to collect the total current value passing through the battery. Among them, the total current value of the current passing through includes both the total discharge current of all interfaces and devices and the total charging current of all interfaces and devices. In addition, because the main function of MSD32 is to cut off the power during high-voltage maintenance, it cannot and does not need to be controlled by VCU. MSD32 has a fuse integrated inside, which is used as an overcurrent protection for the high-voltage circuit of the whole vehicle, and the fuse inside MSD32 can select a suitable fuse according to different vehicle models. When the total current value collected exceeds the preset current threshold, and VCU also has a fault and cannot control the main positive relay 2 or the main negative relay 3 to shut down, MSD32 (Manual Service Disconnect, manual maintenance switch) is turned off to disconnect the entire power distribution process of the high-voltage power distribution system of the electric forklift, to prevent the safety problems caused by the failure of VCU to disconnect the power distribution of the high-voltage power distribution system of the electric forklift in time, and greatly improve the reliability and safety of the solution.

[0112] It should be noted that the current sensor 31 and the main negative relay 3 are directly powered and controlled by the BMS (Battery Management System) or VCU to ensure the reliability of the entire high-voltage system. The remaining relays are controlled by the vehicle controller VCU. The internal acquisition module 16 is responsible for monitoring the internal relay state and the insulation resistance of the high-voltage circuit, and sending it to the vehicle controller VCU for judging relay faults and high-voltage circuit insulation faults. The charging communication harness of the DC charging seat is directly connected to the power battery BMS to realize the communication between the BMS and the charger during DC charging, and send the charging request current and voltage information to the charger. The charger sends the actual output current and voltage information to the BMS. When the gun is plugged in (the vehicle is connected to the charging pile), the BMS completes the judgment of the plug-in signal. The on-board charger OBC6 is directly connected to the AC charging seat, and the BMS communicates with the on-board charger OBC6 to realize the control of OBC6 during AC charging. OBC6 converts the AC power entering from the AC charging seat into the DC power required by the BMS to charge the battery. When the gun is plugged in, OBC6 completes the judgment of the plug-in signal and then sends it to the BMS through the communication signal. The power battery BMS and the vehicle controller VCU communicate with each other. The BMS sends information such as remaining power, battery cell temperature, battery cell voltage, fault code, etc. to the VCU, and the VCU sends control commands, relay status, vehicle fault status and other information to the BMS.

[0113] It should also be noted that if Figure 6 As shown, the electric forklift high-voltage power distribution system is internally integrated with a pre-charge resistor 5 and a pre-charge relay 4. The pre-charge relay 4 is controlled by the vehicle controller VCU. During the high-voltage process, the capacitors in the rear-end DCDC module 7, the water-cooling unit, the cab air conditioning heater, the first MCU, the second MCU, and the third MCU can be pre-charged to reduce the risk of adhesion of the main positive relay 2 and the risk of damage to the rear-end electrical equipment. In addition, this solution adopts a modular design concept. After removing an MCU interface separately, the MCU interface baffle 20 can be used to seal the removed interface to complete the switch from 3 MCU interfaces to 2 MCU interfaces.

[0114] It should be noted that, in this specification, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "comprise", "include" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the statement "comprises a ..." does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0115] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high voltage power distribution system for an electric forklift, characterized in that: include: Battery interface, main positive relay, main negative relay, pre-charge relay, pre-charge resistor; The positive output end of the battery interface is connected to the positive electrode of the battery box, and the negative output end is connected to the negative electrode of the battery box; The first end of the contact of the main positive relay is connected to the positive input end of the battery interface, the second end of the contact is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground; The first end of the contact of the main negative relay is connected to the negative input end of the battery interface, the second end of the contact is respectively connected to the negative output end of the OBC and the negative input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground; The first end of the contact of the pre-charging relay is connected to the first end of the pre-charging resistor, the second end of the contact is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground; The second end of the pre-charging resistor is connected to the positive input end of the battery interface.

2. The high voltage power distribution system for electric forklifts according to claim 1, characterized in that: Also includes: The OBC, the DCDC module, the AC charging interface, the DCDC output interface, the positive copper busbar, and the negative copper busbar; The positive output end of the OBC module is connected to the first end of the positive copper busbar, the negative output end is connected to the first end of the negative copper busbar, the positive input end is connected to the positive output end of the AC charging interface, and the negative input end is connected to the negative output end of the AC charging interface; The second end of the positive copper bar is respectively connected to the positive input end of the DCDC module, the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay; The second end of the negative copper busbar is respectively connected to the negative input end of the DCDC module and the second end of the contact of the main negative relay; The positive output terminal of the DCDC module is connected to the positive input terminal of the DCDC output interface, and the negative output terminal is connected to the negative input terminal of the DCDC output interface; The positive input terminal of the AC charging interface is connected to the positive pole of the AC charging seat; The negative input terminal of the AC charging interface is connected to the negative pole of the AC charging seat.

3. The high voltage power distribution system for electric forklifts according to claim 1, characterized in that: Also includes: A protection device, wherein the first end of the protection device is respectively connected to the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay, and the second end is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, and is used for disconnecting when an overcurrent or overvoltage condition occurs on the output circuit of the OBC and / or the input circuit of the DCDC module.

4. The high voltage power distribution system for electric forklift according to claim 3, characterized in that: The protection device is a main fuse, a first end of which is respectively connected to the second end of the contact of the main positive relay and the second end of the contact of the pre-charge relay, and a second end is respectively connected to the positive output end of the OBC and the positive input end of the DCDC module, and is used for disconnecting when an overcurrent or overvoltage condition occurs in the output circuit of the OBC and / or the input circuit of the DCDC module.

5. The high voltage power distribution system for electric forklifts according to claim 1, characterized in that: Also includes: DC fast charging interface, DC fast charging positive relay, DC fast charging negative relay; The positive input terminal of the DC fast charging interface is connected to the positive output terminal of the DC fast charging device, and the negative input terminal is connected to the negative output terminal of the DC fast charging device; The first end of the contact of the DC fast charging positive relay is connected to the positive output end of the DC fast charging interface, the second end of the contact is respectively connected to the moving contact of the normally open contact of the main positive relay, the second end of the pre-charging resistor and the positive input end of the battery interface, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground; The first end of the contact of the DC fast charging negative relay is connected to the negative output end of the DC fast charging interface, the second end of the contact is respectively connected to the static contact of the normally open contact of the main negative relay, the negative output end of the OBC and the negative input end of the DCDC module, the first end of the coil is connected to the VCU, and the second end of the coil is connected to the ground.

6. The high voltage power distribution system for electric forklift according to claim 5, characterized in that: Also includes: An internal acquisition module, wherein the acquisition end of the internal acquisition module is respectively connected to the main positive relay, the main negative relay, the pre-charging relay, the DC fast charging positive relay, the DC fast charging negative relay, the positive output end of the OBC, the positive input end of the DCDC module, the negative output end of the OBC and the negative input end of the DCDC module, and the output end is connected to the VCU, for transmitting the collected relay states corresponding to the main positive relay, the main negative relay, the DC fast charging positive relay, the DC fast charging negative relay and the pre-charging relay and the insulation resistance between the output circuit of the OBC and the input circuit of the DCDC module to the VCU.

7. The high voltage power distribution system for electric forklifts according to claim 1, characterized in that: Also includes: A first MCU interface, a second MCU interface, a third MCU interface and an MCU interface baffle; The positive input end of the first MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay; The positive input end of the second MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay; The positive input end of the third MCU interface is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module, and the negative input end is connected to the second end of the contact of the main negative relay; The MCU interface baffle is used to block the first MCU interface, the second MCU interface, or the third MCU interface based on the control of the VCU.

8. The high voltage power distribution system for electric forklifts according to claim 1, characterized in that: Also includes: Air conditioning heater high pressure interface, water cooling unit high pressure interface; The first positive input terminal and the second positive input terminal of the air conditioning heater high-voltage interface are respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output terminal of the OBC and the positive input terminal of the DCDC module, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay; The first positive input terminal and the second positive input terminal of the high-pressure interface of the water-cooling unit are respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charging relay, the positive output terminal of the OBC and the positive input terminal of the DCDC module, and the first negative input terminal and the second negative input terminal are connected to the second end of the contact of the main negative relay.

9. The high voltage power distribution system for electric forklift according to claim 8, characterized in that: Also includes: The first air conditioner heater high-voltage relay, the second air conditioner heater high-voltage relay, the first water cooling unit high-voltage relay, the second water cooling unit high-voltage relay, the first air conditioner heater high-voltage fuse, the second air conditioner heater high-voltage fuse, the first water cooling unit high-voltage fuse, the second water cooling unit high-voltage fuse; A first end of the first air conditioning heater high-voltage fuse is connected to a first positive input end of the air conditioning heater high-voltage interface, and a second end is connected to a static contact of a normally open contact of the first air conditioning heater high-voltage relay; The first end of the contact of the first air conditioning heater high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module; A first end of the second air conditioning heater high-voltage fuse is connected to the second positive input end of the air conditioning heater high-voltage interface, and a second end is connected to the second end of the contact of the second air conditioning heater high-voltage relay; The first end of the contact of the second air conditioning heater high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module; A first end of the first water-cooling unit high-voltage fuse is connected to a first positive input end of the water-cooling unit high-voltage interface, and a second end is connected to a second end of a contact of the first water-cooling unit high-voltage relay; The first end of the contact of the first water-cooling unit high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charge relay, the positive output end of the OBC and the positive input end of the DCDC module; A first end of the second water-cooling unit high-voltage fuse is connected to the second positive input end of the water-cooling unit high-voltage interface, and a second end is connected to the second end of the contact of the second water-cooling unit high-voltage relay; The first end of the contact of the second water-cooling unit high-voltage relay is respectively connected to the second end of the contact of the main positive relay, the second end of the contact of the pre-charging relay, the positive output end of the OBC and the positive input end of the DCDC module.

10. The high voltage power distribution system for electric forklift according to any one of claims 1 to 9, characterized in that: Also includes: Current sensor and MSD; The current sensor passes through the negative input terminal of the battery interface, and the output terminal is connected to the BMS, so as to collect the total current value passing through the battery and transmit the total current value to the BMS; The first end of the MSD is connected to the positive input end of the battery interface, and the second end is respectively connected to the first end of the contact of the main positive relay and the second end of the pre-charging resistor.

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