Fully-distributed electro-hydraulic hybrid drive electric excavator

Abstract

The invention provides a fully-distributed electro-hydraulic hybrid drive electric excavator, and relates to the technical field of engineering machinery. Comprising a low-voltage control unit, a high-voltage direct-current power supply unit, a motor driving assembly, a bucket independent driving assembly, a bucket rod independent driving assembly, a movable arm independent driving assembly, a rotation independent driving assembly, a left walking independent driving assembly and a right walking independent driving assembly. The transmission energy efficiency of the whole machine is improved, the energy consumption of the whole machine is reduced and the cruising ability of the electric excavator is fully improved through the technologies of fully-distributed independent driving of an actuator, direct driving of a motor for walking, movable arm potential energy recovery, rotary braking kinetic energy recovery and the like.

Description

Technical Field

[0001] The present invention relates to the technical field of engineering machinery, and in particular to a fully distributed electro-hydraulic hybrid drive electric excavator. Background Art

[0002] Electrification has become an inevitable trend in the development of the excavator industry. Most of the current electric excavators use electric motors to replace traditional internal combustion engines to drive hydraulic pumps to achieve power output. Although this can reduce the energy consumption of the prime mover and reduce emissions to a certain extent, the centralized hydraulic system is still used, resulting in low energy transfer efficiency. The energy efficiency of the hydraulic system is only about 35%, and it is impossible to recycle the recyclable energy generated by the operation of each actuator. In addition, the centralized hydraulic transmission system is highly complex, and maintenance and troubleshooting are difficult. Therefore, the overall energy efficiency of electric excavators is still at a low level, which is difficult to meet the needs of high power and high efficiency, which greatly limits the operating performance and endurance of the excavator, and seriously restricts the green electrification transformation process of the excavator. Summary of the invention

[0003] In response to the above technical problems, the present invention proposes a fully distributed electro-hydraulic hybrid drive electric excavator, which improves the transmission energy efficiency of the whole machine, reduces the energy consumption of the whole machine, and fully improves the endurance of the electric excavator through fully distributed independent drive actuators, motor direct drive walking, boom potential energy recovery and swing brake kinetic energy recovery technologies.

[0004] The present invention adopts the following scheme: A fully distributed electro-hydraulic hybrid drive electric excavator, comprising: a low voltage control unit, a high voltage DC power supply unit, a motor drive assembly, a bucket independent drive assembly, a dipper rod independent drive assembly, a boom independent drive assembly, a slewing independent drive assembly, a left travel independent drive assembly, and a right travel independent drive assembly; The bucket independent driving assembly includes a bucket motor pump, a bucket motor controller, a bucket independent speed regulating valve, and a bucket oil cylinder; the bucket motor controller is electrically connected to the bucket motor pump; the oil suction port of the bucket motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the bucket independent speed regulating valve, and the oil inlet and outlet of the bucket oil cylinder are connected to the output end of the bucket independent speed regulating valve; The arm independent drive assembly includes an arm motor pump, an arm motor controller, an arm independent speed regulating valve, and an arm oil cylinder; wherein the arm motor controller is electrically connected to the arm motor pump; the oil suction port of the arm motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the arm independent speed regulating valve, and the oil inlet and outlet of the arm oil cylinder are connected to the output end of the arm independent speed regulating valve; The boom independent drive assembly includes a boom motor pump, a boom motor controller, a boom independent speed regulating valve, a first boom oil cylinder and a second boom oil cylinder; wherein the boom motor controller is electrically connected to the boom motor pump; the oil suction port of the boom motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the boom independent speed regulating valve, and the oil inlet and outlet of the first boom oil cylinder and the second boom oil cylinder are connected to the output end of the boom independent speed regulating valve; The independent rotary drive assembly includes a rotary motor, a rotary motor controller, and an upper vehicle rotary mechanism; the rotary motor controller is electrically connected to the rotary motor, and the rotary motor is mechanically connected to the upper vehicle rotary mechanism to control the rotation of the upper vehicle rotary mechanism; The left walking independent drive assembly includes a left walking motor, a left walking motor controller, a left walking reducer, and a left walking crawler; the left walking motor is mechanically connected to the left walking reducer, and the left walking reducer is mechanically connected to the left walking crawler; The right travel independent drive assembly includes a right travel motor, a right travel motor controller, a right travel reducer, and a right travel crawler; the right travel motor is mechanically connected to the right travel reducer, and the right travel reducer is mechanically connected to the right travel crawler; The high-voltage direct current power supply unit is electrically connected to the energy distribution unit to provide high-voltage direct current; the energy distribution unit is electrically connected to the motor driver to distribute high-voltage electrical energy to the motor driver; The motor drive assembly is electrically connected to the bucket motor pump, the arm motor pump, the boom motor pump, the slewing motor, the left travel motor and the right travel motor to drive the operation of each motor pump, the upper vehicle turntable and the travel crawler; The low voltage control unit is electrically connected to the high voltage DC power supply unit, the energy distribution unit, and each independent drive component to control the operating state of the entire system.

[0005] Furthermore, the boom motor pump includes a boom motor and a pump motor, and the boom motor and the pump motor are mechanically connected to drive the pump motor, and the boom cylinder is independently driven through the boom independent speed control valve; when the boom is lifted, the pump motor works in a pump condition, and outputs high-pressure oil to drive the boom cylinder to extend; when the boom is lowered, the pump motor works in a motor condition, and the gravitational potential energy of the boom lowering is converted into hydraulic energy, which is finally absorbed by the boom motor in the form of electrical energy, stored in the high-voltage DC power supply unit or consumed by other power units; wherein the speed and direction of the boom cylinder are jointly regulated by the output flow change of the boom motor pump and the valve core opening change of the boom independent speed control valve.

[0006] Furthermore, the boom cylinder is independently driven by an boom motor pump, and the pressure oil output by the boom motor pump all flows into the boom cylinder via the independent boom speed regulating valve, thereby realizing independent driving of the boom cylinder; the speed of the boom cylinder in the independent driving state is jointly regulated by the output flow change of the boom motor pump and the valve core opening change of the independent boom speed regulating valve, and the speed direction switching is realized by switching the oil circuit direction by the boom speed regulating valve; the boom motor pump includes a boom motor and a boom hydraulic pump, and the output flow of the boom motor pump is jointly regulated by the speed change of the boom motor and the displacement change of the boom variable pump.

[0007] Furthermore, the bucket cylinder is independently driven by a bucket motor pump, and the pressure oil output by the bucket motor pump all flows into the bucket cylinder through the bucket independent speed control valve to realize independent driving of the bucket cylinder; the speed of the bucket cylinder in the independent driving state is jointly regulated by the output flow change of the bucket motor pump and the change of the valve core opening of the bucket independent speed control valve, and the direction switching of its speed is realized by switching the oil circuit direction of the bucket independent speed control valve; the bucket motor pump includes a bucket motor and a bucket variable pump, and the output flow of the bucket motor pump is jointly regulated by the speed change of the bucket motor and the displacement change of the bucket variable pump.

[0008] Furthermore, the left walking crawler mechanism and the right walking crawler mechanism are independently driven by the left walking motor and the right walking motor respectively. The forward, backward and turning of the tracks are realized by controlling the rotation speed and steering control of the left walking motor and the right walking motor. The steering is realized by controlling the difference in rotation speed of the left walking motor and the right walking motor. The forward or backward movement is realized by controlling the rotation speed and steering of the left walking motor and the right walking motor to be the same.

[0009] Furthermore, the on-board slewing mechanism adopts a slewing motor to drive the slewing reducer for slewing drive, and during slewing braking, the slewing motor provides a braking torque to feed back the slewing braking kinetic energy to the motor drive assembly and the high-voltage DC power supply unit.

[0010] Furthermore, the energy distribution unit is electrically connected to each motor controller, and each motor controller controls the operating state of each drive motor by adjusting the current, voltage or frequency and electrical parameters to drive the bucket motor, dipper arm motor, boom motor, slewing motor, left travel motor and right travel motor to work.

[0011] Furthermore, the high-voltage DC power supply unit is a power lithium-ion battery, or a hydrogen energy battery, or a DC power supply rectified by an AC power grid.

[0012] Beneficial effects: 1. The electric excavator based on the fully distributed electrostatic direct drive system of this application can independently drive the boom, dipper rod, bucket, rotation and whole machine travel through multiple motor pumps and multiple independent speed regulating valve groups, breaking the traditional way of relying on centralized multi-way valves for flow distribution, fundamentally solving the pressure coupling problem between multiple actuators, and avoiding a large amount of energy loss. This improvement significantly improves the energy efficiency of the whole system and achieves more efficient energy conversion and utilization.

[0013] 2. By using an independent drive motor to drive the pump motor to drive the boom, when the boom is lowered, the pump motor operates as a motor, recovering the gravitational potential energy generated during the boom lowering process, converting it into electrical energy and storing it in the high-voltage power supply system. At the same time, the independent slewing electric drive assembly drives the upper vehicle to slew, and under the slewing braking condition, the kinetic energy during the slewing braking process can be converted into electrical energy and stored in the high-voltage power supply system, thereby further improving the energy utilization efficiency of the entire machine.

[0014] 3. Dual motors are used to independently drive the left and right travel of the excavator. The motor drives the travel reducer to directly drive the travel tracks. By independently adjusting the power and speed of the left and right travel motors, more precise turning and walking control of the travel tracks can be achieved. The independent drive mode allows the left and right tracks to be independently controlled according to different working conditions, thereby improving the stability of the travel system and enhancing the traction ability of the excavator in complex environments such as steep slopes and slippery environments. It significantly improves the operational flexibility of the excavator in complex terrain and narrow spaces, thereby reducing unnecessary energy consumption and improving the energy utilization efficiency of the entire machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural schematic diagram of a fully distributed electro-hydraulic hybrid drive electric excavator according to an embodiment of the present invention; Figure numerals: low voltage control unit 1; high voltage DC power supply unit 2; energy distribution unit 3; bucket independent drive assembly 4; bucket motor controller 41; bucket motor pump 42; bucket motor 421; bucket variable pump 422; bucket independent speed regulating valve 43; bucket cylinder 44; arm independent drive assembly 5; arm motor controller 51; arm motor pump 52; arm motor 521; arm variable pump 522; arm independent speed regulating valve 53; arm cylinder 54; boom independent drive assembly 6; boom motor controller 61; boom motor pump 62; boom motor 621; pump motor 622; boom independent speed regulating valve 63; first boom cylinder 64; second boom cylinder 65; left travel independent drive assembly 7; left travel motor controller 71; left travel motor 72; left travel crawler mechanism 73; slewing independent drive assembly 8; slewing motor controller 81; slewing motor 82; vehicle slewing mechanism 83; right travel independent drive assembly 9; right travel motor controller 91; right travel motor 92; right travel crawler mechanism 93. DETAILED DESCRIPTION

[0016] Combination Figure 1 The present embodiment provides a fully distributed electro-hydraulic hybrid drive electric excavator, including: a low voltage control unit 1; a high voltage DC power supply unit 2; an energy distribution unit 3; a bucket independent drive component 4; a bucket motor controller 41; a bucket motor pump 42; a bucket motor 421; a bucket variable pump 422; a bucket independent speed regulating valve 43; a bucket cylinder 44; an arm independent drive component 5; an arm motor controller 51; an arm motor pump 52; an arm motor 521; an arm variable pump 522; an arm independent speed regulating valve 53; an arm cylinder 54; an arm independent Drive assembly 6; boom motor controller 61; boom motor pump 62; boom motor 621; pump motor 622; boom independent speed regulating valve 63; first boom cylinder 64, second boom cylinder 65; left travel independent drive assembly 7; left travel motor controller 71; left travel motor 72; left travel track mechanism 73; slewing independent drive assembly 8; slewing motor controller 81; slewing motor 82; vehicle slewing mechanism 83; right travel independent drive assembly 9; right travel motor controller 91; right travel motor 92; right travel track mechanism 93.

[0017] Combination Figure 1 In this embodiment, the bucket motor pump 42, the arm motor pump 52, and the boom motor pump 62 respectively drive the bucket cylinder 44, the arm cylinder 54, the first boom cylinder 64, and the second boom cylinder 65 independently through the bucket independent speed regulating valve 43, the arm independent speed regulating valve 53, and the boom independent speed regulating valve 63; the rotary motor 82 drives the rotary reducer to directly drive the upper vehicle rotary mechanism 83 to rotate; the left travel motor 72 and the right travel motor 92 drive their respective travel reducers to directly drive the travel tracks to travel.

[0018] Specifically, the oil inlet and return ports of the bucket oil cylinder 44 are connected to the output end of the bucket independent speed regulating valve 43, and the input of the bucket independent speed regulating valve 43 comes from the output flow of the bucket motor pump 42, so the speed of the bucket oil cylinder 44 is jointly regulated by the valve core opening of the bucket independent speed regulating valve and the output flow of the bucket motor pump 42; the bucket motor pump 42 is composed of a bucket motor 421 and a bucket variable pump 422, and the output flow of the bucket motor pump 42 is jointly regulated by the speed change of the bucket motor 421 and the displacement change of the bucket variable pump 422. The bucket variable pump 422 is a variable pump.

[0019] Similarly, the oil inlet and return ports of the boom cylinder 54 are connected to the output end of the boom independent speed regulating valve 53. The input of the boom independent speed regulating valve 53 comes from the output flow of the boom motor pump 52. Therefore, the speed of the boom cylinder 54 is regulated by the valve core opening of the boom independent speed regulating valve 53 and the output flow of the boom motor pump 52. The boom motor pump 52 is composed of a boom motor 521 and a boom variable pump 522. The output flow of the boom motor pump 52 is regulated by the speed change of the boom motor 521 and the displacement change of the boom variable pump 522.

[0020] The oil inlet and return ports of the first boom oil cylinder 64 and the second boom oil cylinder 65 are connected to the boom independent speed regulating valve 63, and the first boom oil cylinder 64 and the second boom oil cylinder 65 are independently driven through the boom motor pump 62 and the boom independent speed regulating valve 63. The boom motor pump 62 is composed of a boom motor 621 and a pump motor 622. When the excavator performs the boom lowering operation, due to the effect of gravity, the pump motor 622 operates in the motor operation in the reverse direction, converting the gravitational potential energy generated during the lowering process into electrical energy, and feeding the energy back to the battery pack through the boom motor 621 through the energy distribution unit 3, thereby improving energy utilization.

[0021] like Figure 1 As shown, in this embodiment, the vehicle slewing mechanism 83 is mechanically connected to the slewing motor 82, and the slewing motor 82 is electrically connected to the slewing motor controller 81, wherein the slewing motor 82 directly drives the vehicle slewing mechanism to rotate by driving the slewing reducer, and the vehicle control unit collects the rotation signal of the whole machine operating handle, sends the control signal to the slewing motor controller 81, and sends the control information to the slewing motor 82 through the slewing motor controller 81 to drive the whole machine to rotate. The vehicle control unit described here is an existing control system, which will not be specifically expanded here.

[0022] like Figure 1As shown, the left walking crawler mechanism 73 and the right walking crawler mechanism 93 are independently driven by dual motors, and the left walking crawler mechanism 73 and the right walking crawler mechanism 93 are mechanically connected to the left walking motor 72 and the right walking motor 92 respectively, and the left walking motor 72 and the right walking motor 92 are electrically connected to the left walking motor controller 71 and the right walking motor controller 91 respectively, wherein the left walking crawler mechanism 73 and the right walking crawler mechanism 93 drive the walking reducer to directly drive the walking crawler to work through the left walking motor 72 and the right walking motor 92 respectively, and the vehicle control unit collects the walking handle signal of the whole machine operation, sends the control signal to the left walking motor controller 71 and the right walking motor controller 91, and sends the control information to the left walking motor 72 and the right walking motor 92 through the left walking motor controller 71 and the right walking motor controller 91 to drive the whole machine to walk.

[0023] Specifically, when facing a walking and turning condition, taking left walking as an example, the vehicle control unit collects the travel signal of the walking handle of the whole machine and sends control information to the left walking motor 72 and the right walking motor 92. For example, by controlling the right walking motor 92 to accelerate and the left walking motor 72 to decelerate, the two walking mechanisms produce a differential, so that the excavator turns left. Similarly, when facing a right walking condition, the control signal is sent to accelerate the left walking motor 72 and decelerate the right walking motor 92, so that the excavator turns right.

[0024] like Figure 1 As shown, in this embodiment, the motor drive assembly includes a bucket motor controller 41, a stick motor controller 51, a boom motor controller 61, a slewing motor controller 81, a left travel motor controller 71, and a right travel motor controller 91; the output end of the motor drive assembly is electrically connected to each motor, and is used to send each motor status information to the vehicle control unit, including motor speed, motor torque and fault information, etc., and at the same time receive the target control signal of the vehicle control unit to drive each motor to work.

[0025] like Figure 1As shown, in this embodiment, the high-voltage DC power supply unit 2 provides a high-voltage DC power supply for the whole machine, communicates data with the whole vehicle system through the CAN bus, monitors the temperature of the power battery, and transmits the temperature data to the low-voltage control unit 1 of the whole vehicle. By continuously monitoring the key parameters such as the voltage, temperature and current of the battery cell, a comprehensive assessment and health management of the battery status is achieved. The high-voltage DC power supply unit 2 and the power distribution unit 3 work together to provide the required electrical energy for the motor drive system and store the recovered energy. The output end of each motor controller is connected to each drive motor, which is responsible for transmitting the operating status information of the motor to the motor controller, and at the same time receives the control signal from the low-voltage control unit 1, thereby driving the operation of each motor pump. In this embodiment, the high-voltage DC power supply unit 2 can be a power lithium-ion battery, or a hydrogen energy battery, or a DC power supply after rectification of the AC power grid.

[0026] This embodiment scheme uses multiple groups of motor pumps and multiple independent speed regulating valve groups to independently drive the boom, dipper rod, bucket, rotation and whole machine travel in a distributed manner, breaking the traditional method of relying on centralized multi-way valves for flow distribution, fundamentally solving the pressure coupling problem between multiple actuators, and avoiding a large amount of energy loss; significantly improving the energy efficiency of the whole machine system, and achieving more efficient energy conversion and utilization. Through fully distributed independent drive actuators, motor direct drive travel, boom potential energy recovery and rotation brake kinetic energy recovery and other technologies, the transmission energy efficiency of the whole machine is improved, the energy consumption of the whole machine is reduced, and the endurance of the electric excavator is fully improved.

[0027] It should be understood that the above are only preferred implementations of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention.

[0028] The above description of the drawings used in the implementation manner only illustrates certain embodiments of the present invention and should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

Claims

1. A fully distributed electro-hydraulic hybrid drive electric excavator, characterized in that: include: Low voltage control unit, high voltage DC power supply unit, motor drive assembly, bucket independent drive assembly, stick independent drive assembly, boom independent drive assembly, slewing independent drive assembly, left travel independent drive assembly, right travel independent drive assembly; The bucket independent driving assembly includes a bucket motor pump, a bucket motor controller, a bucket independent speed regulating valve, and a bucket oil cylinder; the bucket motor controller is electrically connected to the bucket motor pump; the oil suction port of the bucket motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the bucket independent speed regulating valve, and the oil inlet and outlet of the bucket oil cylinder are connected to the output end of the bucket independent speed regulating valve; The arm independent drive assembly includes an arm motor pump, an arm motor controller, an arm independent speed regulating valve, and an arm oil cylinder; wherein the arm motor controller is electrically connected to the arm motor pump; the oil suction port of the arm motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the arm independent speed regulating valve, and the oil inlet and outlet of the arm oil cylinder are connected to the output end of the arm independent speed regulating valve; The boom independent drive assembly includes a boom motor pump, a boom motor controller, a boom independent speed regulating valve, a first boom oil cylinder and a second boom oil cylinder; wherein the boom motor controller is electrically connected to the boom motor pump; the oil suction port of the boom motor pump is connected to the oil tank, and the oil outlet is connected to the input end of the boom independent speed regulating valve, and the oil inlet and outlet of the first boom oil cylinder and the second boom oil cylinder are connected to the output end of the boom independent speed regulating valve; The independent rotary drive assembly includes a rotary motor, a rotary motor controller, and an upper vehicle rotary mechanism; the rotary motor controller is electrically connected to the rotary motor, and the rotary motor is mechanically connected to the upper vehicle rotary mechanism to control the rotation of the upper vehicle rotary mechanism; The left walking independent drive assembly includes a left walking motor, a left walking motor controller, a left walking reducer, and a left walking crawler; the left walking motor is mechanically connected to the left walking reducer, and the left walking reducer is mechanically connected to the left walking crawler; The right travel independent drive assembly includes a right travel motor, a right travel motor controller, a right travel reducer, and a right travel crawler; the right travel motor is mechanically connected to the right travel reducer, and the right travel reducer is mechanically connected to the right travel crawler; The high-voltage direct current power supply unit is electrically connected to the energy distribution unit to provide high-voltage direct current; the energy distribution unit is electrically connected to the motor driver to distribute high-voltage electrical energy to the motor driver; The motor drive assembly is electrically connected to the bucket motor pump, the arm motor pump, the boom motor pump, the slewing motor, the left travel motor and the right travel motor to drive the operation of each motor pump, the upper vehicle turntable and the travel crawler; The low voltage control unit is electrically connected to the high voltage DC power supply unit, the energy distribution unit, and each independent drive component to control the operating state of the entire system.

2. A fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The boom motor pump includes a boom motor and a pump motor, and the boom motor and the pump motor are mechanically connected to drive the pump motor, and the boom cylinder is independently driven through the boom independent speed control valve; when the boom is lifted, the pump motor works in a pump condition, and outputs high-pressure oil to drive the boom cylinder to extend; when the boom is lowered, the pump motor works in a motor condition, and the gravitational potential energy of the boom lowering is converted into hydraulic energy, which is finally absorbed by the boom motor in the form of electrical energy, stored in the high-voltage DC power supply unit or consumed by other power units; wherein the speed and direction of the boom cylinder are jointly regulated by the output flow change of the boom motor pump and the valve core opening change of the boom independent speed control valve.

3. A fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The arm oil cylinder is independently driven by the arm motor pump, and the pressure oil output by the arm motor pump flows into the arm oil cylinder through the arm independent speed regulating valve to realize independent driving of the arm oil cylinder; The speed of the boom cylinder in the independent driving state is jointly adjusted by the output flow change of the boom motor pump and the change of the valve core opening of the boom independent speed regulating valve, and the direction switching of the speed is achieved by the boom speed regulating valve switching the oil circuit direction; The arm motor pump comprises an arm motor and an arm hydraulic pump, and the output flow of the arm motor pump is adjusted by the rotation speed change of the arm motor and the displacement change of the arm variable pump.

4. A fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The bucket cylinder is independently driven by a bucket motor pump, and the pressure oil output by the bucket motor pump flows into the bucket cylinder through the bucket independent speed regulating valve to realize independent driving of the bucket cylinder; The speed of the bucket cylinder in the independent driving state is jointly adjusted by the output flow change of the bucket motor pump and the change of the valve core opening of the bucket independent speed regulating valve, and the direction switching of the speed is achieved by the independent speed regulating valve of the bucket switching the oil circuit direction; The bucket motor pump comprises a bucket motor and a bucket variable displacement pump, and the output flow of the bucket motor pump is adjusted by the rotation speed change of the bucket motor and the displacement change of the bucket variable displacement pump.

5. The fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The left walking crawler mechanism and the right walking crawler mechanism are independently driven by the left walking motor and the right walking motor respectively, and the forward, backward and turning movement of the crawler are realized by controlling the rotation speed and steering control of the left walking motor and the right walking motor.

6. A fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The vehicle slewing mechanism adopts a slewing motor to drive the slewing reducer for slewing driving, and during slewing braking, the slewing motor provides a braking torque to feed back the slewing braking kinetic energy to the motor drive assembly and the high-voltage DC power supply unit.

7. A fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The energy distribution unit is electrically connected to each motor controller, and each motor controller controls the operating state of each drive motor by adjusting the current, voltage or frequency and electrical parameters to drive the bucket motor, dipper arm motor, boom motor, slewing motor, left travel motor and right travel motor to work.

8. The fully distributed electro-hydraulic hybrid drive electric excavator according to claim 1, characterized in that: The high-voltage direct current power supply unit is a power lithium-ion battery, or a hydrogen energy battery, or a direct current power supply rectified by an alternating current grid.

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