A dual-mode electro-hydraulic actuator

Abstract

The present invention discloses a dual-mode electro-hydraulic actuator, which includes a multi-input power supply, a drive control unit, a dual-mode multi-phase motor, and a hydraulic system. The multi-input power supply includes a battery pack power supply and a grid power supply. The drive control unit selects one of the battery pack power supply and the grid power supply to drive the dual-mode multi-phase motor. The hydraulic system includes a bidirectional hydraulic pump and an actuator cylinder. The bidirectional hydraulic pump provides hydraulic energy under the drive of the dual-mode multi-phase motor to achieve the bidirectional actuation of the actuator cylinder. While retaining the fault position function of the electro-hydraulic actuator, the present invention removes the complex and heavy accumulator, and has the advantages of small volume, large thrust, high degree of intelligence, high fault tolerance ability, and strong emergency handling ability.

Description

Technical Field

[0001] The present invention relates to the field of industrial control valves, and particularly to a dual-mode electro-hydraulic actuator. Background Art

[0002] Industrial control valves are mainly used in large industrial enterprises. In industrial automated production, control valves are one of the most important supporting devices for process automation control, and are widely used in fields such as petroleum, chemical industry, metallurgy, iron and steel, paper making, and air separation.

[0003] As the power mechanism of a control valve, the fault position function of a traditional electro-hydraulic actuator is achieved by adding an accumulator to the hydraulic system. When the electro-hydraulic actuator can work normally, the control system controls the hydraulic system to fill the accumulator with oil, and stores a certain amount of pressure energy through the accumulator. Once the power supply of the electro-hydraulic actuator fails and it cannot operate normally, the pressure energy in the accumulator is released to push the actuator to a preset position, thereby realizing the function of the fault position. As a pressure vessel, the accumulator is large in volume, heavy in weight, and complex in operation. After adding the accumulator to the hydraulic system of the electro-hydraulic actuator, the volume and weight increase significantly, and the whole system is complex and bulky, which adds an extremely heavy burden to transportation, installation, and maintenance. Summary of the Invention

[0004] The purpose of the present invention is to overcome the above-mentioned deficiencies of the prior art, and provide a dual-mode electro-hydraulic actuator, which while retaining the fault position function of the electro-hydraulic actuator, removes the complex and bulky accumulator, and has the advantages of small volume, large thrust, high degree of intelligence, high fault tolerance ability, and strong emergency handling ability.

[0005] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0006] A dual-mode electro-hydraulic actuator includes a multi-input power supply, a drive control unit, a dual-mode multi-phase motor, and a hydraulic system. The multi-input power supply includes a battery pack power supply and a grid power supply. The drive control unit selects one of the battery pack power supply and the grid power supply to drive the dual-mode multi-phase motor. The hydraulic system includes a bidirectional hydraulic pump and an actuator cylinder. The bidirectional hydraulic pump provides hydraulic energy under the drive of the dual-mode multi-phase motor to realize the bidirectional actuation of the actuator cylinder.

[0007] The multi-input power supply receives a high-voltage power input from the grid power supply and a low-voltage power input from the battery pack power supply. The stator of the dual-mode multi-phase motor includes a low-voltage winding and a high-voltage winding. When using the grid power supply, the high-voltage winding works, and the dual-mode multi-phase motor is in a high-voltage and small-current state. When using the battery pack power supply, the low-voltage winding works, and the dual-mode multi-phase motor is in a low-voltage and large-current state.

[0008] The drive control unit includes a mode selector, a control system, and a power drive module. The power drive module includes a first power drive module and a second power drive module. The mode selector selects one of the battery pack power supply and the grid power supply and outputs it to the control system. The control system controls the second power drive module to output a high-voltage drive circuit or controls the first power drive module to output a low-voltage drive circuit according to the selection of the mode selector, thereby controlling the dual-mode multi-phase motor to operate at different voltages.

[0009] The mode selector includes an AC-DC power supply, an electromagnetic coil, a return spring, and a mode selection switch. The AC-DC power supply is connected to the grid power supply, and the electromagnetic coil is connected to the AC-DC power supply. When using the grid power supply, the AC-DC power supply outputs a DC voltage, and the electromagnetic coil is energized to make the mode selection switch close. The mode selection switch is connected to the grid power supply. When the grid power supply fails, the electromagnetic coil loses power, and the mode selection switch is connected to the battery pack power supply under the action of the return spring.

[0010] The control system includes a main control chip and a multiplexer. The main control chip receives signals from the mode selector. The main control chip includes 6 PWM signals. The multiplexer includes a first multiplexer and a second multiplexer. The first multiplexer and the second multiplexer process 3 PWM signals respectively. The SEL pin of the multiplexer is connected to the SEL pin of the main control chip. When the main control chip outputs a low level, the second multiplexer outputs the PWM signal to the high-voltage drive circuit. When the main control chip outputs a high level, the first multiplexer outputs the PWM signal to the low-voltage drive circuit.

[0011] The control system includes buffers. The buffers include a first buffer and a second buffer. The first buffer is connected to the output of the first multiplexer, and the second buffer is connected to the output of the second multiplexer.

[0012] The control system includes an isolated gate drive circuit. The high-voltage drive circuit is driven by the isolated gate drive circuit. The isolated gate drive circuit includes an isolated gate drive circuit one and an isolated gate drive circuit two for controlling U1. When the 1Y output of buffer two is at a high level and the 2Y output is at a low level, the isolated gate drive circuit one outputs a high level and the isolated gate drive circuit two outputs a low level. The upper bridge arm of the U-phase of the power drive module two conducts and the lower bridge arm is cut off. U1 is connected to the DC bus DCH+. U1 outputs a high voltage. When the 1Y output of buffer two is at a low level and the 2Y output is at a high level, the isolated gate drive circuit one outputs a low level and the isolated gate drive circuit two outputs a high level. The upper bridge arm of the U-phase of the power drive module two is cut off and the lower bridge arm conducts. U1 is connected to the DC bus DCH-. U1 outputs a low voltage. When the 1Y and 2Y outputs of buffer two are both at a high level or a low level, both the isolated gate drive circuit one and the isolated gate drive circuit two are cut off, and U1 is in a floating state. The driving principles of V1 and W1 are the same as that of U1.

[0013] The control system includes a bootstrap gate circuit. The low-voltage drive circuit is driven by the bootstrap gate circuit. The bootstrap gate circuit includes a bootstrap gate circuit one for controlling U2. When the 1Y output of buffer one is at a high level and the 2Y output is at a low level, the HO pin of the bootstrap gate circuit one outputs a high level and the LO pin outputs a low level. The upper bridge arm of the U-phase of the power drive module one conducts and the lower bridge arm is cut off. U2 is connected to the DC bus DCL+. U2 outputs a high voltage. When the 1Y output of buffer one is at a low level and the 2Y output is at a high level, the HO pin of the bootstrap gate circuit one outputs a low level and the LO pin outputs a high level. The upper bridge arm of the U-phase of the power drive module one is cut off and the lower bridge arm conducts. U2 is connected to the DC bus DCL-. U2 outputs a low voltage. When the 1Y and 2Y outputs of buffer one are both at a high level, the bootstrap gate circuit one enters a protection state, and the HO pin and the LO pin both output a low level. When the 1Y and 2Y outputs of buffer one are both at a low level, the HO pin and the LO pin of the bootstrap gate circuit one both output a low level, and U2 is in a floating state. The driving principles of V2 and W2 are the same as that of U2.

[0014] The main control chip is connected to the position detection circuit.

[0015] The hydraulic system includes a boost tank, a volume compensation valve, a position locking valve 1, a position locking valve 2, an overload safety valve 1, and an overload safety valve 2. The boost tank is connected to the volume compensation valve, the overload safety valve 1, the overload safety valve 2, and a two-way hydraulic pump. The position locking valve 1 and the overload safety valve 1 are installed on the oil path from the two-way hydraulic pump to the rodless chamber of the actuator cylinder. The position locking valve 2 and the overload safety valve 2 are installed on the oil path from the two-way hydraulic pump to the rod chamber of the actuator cylinder. One end of the overload safety valve 1 is connected to the oil path between the position locking valve 1 and the rodless chamber, and the other end of the overload safety valve 1 is connected to the boost tank. One end of the overload safety valve 2 is connected to the oil path between the position locking valve 2 and the rod chamber, and the other end of the overload safety valve 2 is connected to the boost tank.

[0016] The beneficial effects of the present invention are:

[0017] 1. Using dual-mode drive, in case of power failure or emergency conditions, the actuator can be operated to the preset position through the battery power of the electro-hydraulic actuator to achieve the function of the fault position, eliminating the trouble of manual operation and requiring no human intervention. It is simple and reliable. While retaining the electro-hydraulic actuator's fault position function, the complex and bulky accumulator is removed, truly giving full play to the advantages of the electro-hydraulic actuator's small size, large thrust, and high intelligent program.

[0018] 2. The electro-hydraulic actuator has a dual-redundancy drive system, which adopts a combination of high-voltage drive and low-voltage drive to increase the redundancy of the electro-hydraulic actuator. In this system, the MOSFET IPM module and the IGBT IPM module can work independently. If any module fails, the other module can be used to complete the action independently, which improves the reliability of the system.

[0019] 3. Use a power drive module to drive a bidirectional hydraulic pump to replace the accumulator assembly in the traditional electro-hydraulic actuator. Use a MOSFET IPM module to drive it. It has a simple structure, small size, light weight, and is easy to use, which greatly facilitates the installation and subsequent maintenance of the electro-hydraulic actuator.

[0020] 4. It has a low-voltage driving function and can be used under the condition of battery power supply. In actual applications, once the external power grid fails or there is no external power grid power supply, the battery power supply can be used to work, which increases the convenience of user use. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is the principle diagram of the present invention;

[0022] Figure 2 It is a driving schematic diagram of the dual-mode multi-phase motor of the present invention;

[0023] Figure 3 is a schematic diagram of a mode selector of the present invention;

[0024] Figure 4 is the driving schematic diagram of a dual-mode multi-phase motor;

[0025] Figure 5 is the schematic diagram of the cooperation of the control system, multiplexer, and buffer of the present invention;

[0026] Figure 6 is the schematic diagram of the cooperation of the buffer, bootstrap gate circuit, isolated gate drive circuit, and power drive module of the present invention.

[0027] In the figure: multi-input power supply 1, drive control unit 2, dual-mode multi-phase motor 3, hydraulic system 4, battery pack power supply 5, mode selector 6, control system 7, power drive module 8, power drive module one 8a, power drive module two 8b, bidirectional hydraulic pump 9, pressurized oil tank 10, volume compensation valve 11, position locking valve one 12a, position locking valve two 12b, overload safety valve one 13a, overload safety valve two 13b, actuator 14, low-voltage winding 17, high-voltage winding 18, AC-DC power supply 19, electromagnetic coil 20, return spring 21, mode selection switch 22, position detection circuit 23, multiplexer 24, multiplexer one 24a, multiplexer two 24b, buffer 25, buffer one 25a, buffer two 25b, bootstrap gate circuit 26, bootstrap gate circuit one 26a, isolated gate drive circuit 27, isolated gate drive circuit one 27a, isolated gate drive circuit two 27b, main control chip 28. Specific embodiments

[0028] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments:

[0029] As Figures 1 - 6 shown, a dual-mode electro-hydraulic actuator includes a multi-input power supply 1, a drive control unit 2, a dual-mode multi-phase motor 3, and a hydraulic system 4. The multi-input power supply 1 includes a battery pack power supply 5 and a grid power supply. The drive control unit 2 selects one of the battery pack power supply 5 and the grid power supply to drive the dual-mode multi-phase motor 3. The hydraulic system 4 includes a bidirectional hydraulic pump 9, an actuator 14, a pressurized oil tank 10, a volume compensation valve 11, a position locking valve one 12a, a position locking valve two 12b, an overload safety valve one 13a, and an overload safety valve two 13b. The bidirectional hydraulic pump 9 is connected to the dual-mode multi-phase motor 3 through a coupling. The bidirectional hydraulic pump 9 provides hydraulic energy under the drive of the dual-mode multi-phase motor 3 to realize the bidirectional actuation of the actuator 14, which can not only drive the valve to complete the opening and closing state conversion but also be used to accurately control the valve opening. The hydraulic system 4 is a pump control system, and the speed of the bidirectional hydraulic pump 9 is adjusted by adjusting the speed of the dual-mode multi-phase motor 3 to realize the speed control of the actuator 14.

[0030] Referring to Figure 1, the pressure boosting oil tank 10 is connected to a volume compensation valve 11, an overloading safety valve I 13a, an overloading safety valve II 13b, and a two-way hydraulic pump 9. The position locking valve I 12a and the overloading safety valve I 13a are installed on the oil path of the rodless cavity of the two-way hydraulic pump 9 leading to the actuating cylinder 14. The position locking valve II 12b and the overloading safety valve II 13b are installed on the oil path of the rod cavity of the two-way hydraulic pump 9 leading to the actuating cylinder 14. One end of the overloading safety valve I 13a is connected to the oil path between the position locking valve I 12a and the rodless cavity, and the other end of the overloading safety valve I 13a is connected to the pressure boosting oil tank 10. One end of the overloading safety valve II 13b is connected to the oil path between the position locking valve II 12b and the rod cavity, and the other end of the overloading safety valve II 13b is connected to the pressure boosting oil tank 10.

[0031] Refer to Figure 1 , when starting to operate, the electromagnets of the position locking valve I 12a and the position locking valve II 12b are energized, the oil path is connected, and the dual-mode multi-phase motor 3 drives the two-way hydraulic pump 9 to work. When the two-way hydraulic pump 9 rotates forward, the high-pressure oil fluid enters the rodless cavity of the actuating cylinder 14 through the position locking valve I 12a, and the actuating cylinder 14 extends outwards. When the two-way hydraulic pump 9 rotates reversely, the high-pressure oil fluid enters the rod cavity of the actuating cylinder 14 through the position locking valve II 12b, and the actuating cylinder 14 retracts. When the external load increases, the internal oil fluid pressure of the actuating cylinder 14 increases. When the pressure increases to exceed the pressure set by the overloading safety valve I 13a or the overloading safety valve II 13b, the overloading safety valve I 13a and the overloading safety valve II 13b open, stabilizing the system pressure at the set pressure to prevent the hydraulic system 4 from being damaged due to excessive pressure. Since the volume of the rod cavity of the actuating cylinder 14 is different from that of the rodless cavity, when the actuating cylinder 14 operates, the volume of the oil fluid entering the actuating cylinder 14 and the volume of the oil fluid flowing out of the actuating cylinder 14 are different at the same moment, and it is necessary to use the pressure boosting oil tank 10 to store the oil fluid. When the oil fluid entering the actuating cylinder 14 is greater than the oil fluid flowing out of the actuating cylinder 14 (i.e., the rodless cavity enters and the rod cavity exits), the two-way hydraulic pump 9 sucks oil from the pressure boosting oil tank 10 for supplement. When the oil fluid flowing out of the actuating cylinder 14 is greater than the oil fluid entering the actuating cylinder 14 (i.e., the rod cavity enters and the rodless cavity exits), the volume compensation valve 11 opens, and the excess oil fluid enters the pressure boosting oil tank 10 for storage through the volume compensation valve 11. After the operation ends, the position locking valve I 12a and the position locking valve II 12b are de-energized and locked, the dual-mode multi-phase motor 3 stops, and the actuating cylinder 14 remains at the target position.

[0032] Refer to Figure 1 , Figure 2, the multi-input power supply 1 receives a high-voltage power input from the grid power supply and a low-voltage power input from the battery pack power supply 5. The stator of the dual-mode multi-phase motor 3 includes a low-voltage winding 17 and a high-voltage winding 18 with different voltage levels. When using the grid power supply, the high-voltage winding 18 operates, and the dual-mode multi-phase motor 3 is in a high-voltage and low-current state. When using the battery pack power supply 5, the low-voltage winding 17 operates, and the dual-mode multi-phase motor 3 is in a low-voltage and high-current state. The high-voltage winding 18 is connected to the IGBT IPM (refer to Figure 6 In, IGBT IPM drives -U, V, W), and the low-voltage winding 17 is connected to the MOSFET IPM (refer to Figure 6 In, MOSFET IPM drives -U, V, W).

[0033] Refer to Figure 1 , the drive control unit 2 includes a mode selector 6, a control system 7, and a power drive module 8, which can select the grid power supply or the battery pack power supply 5 according to different working conditions to control the normal operation of the electro-hydraulic actuator. The power drive module 8 includes a power drive module one 8a and a power drive module two 8b. The dual-mode multi-phase motor 3 is driven to operate through the power drive module 8. The mode selector 6 selects one of the battery pack power supply 5 and the grid power supply and outputs it to the control system 7. The control system 7 controls the power drive module two 8b to output a high-voltage drive circuit or controls the power drive module one 8a to output a low-voltage drive circuit according to the selection of the mode selector 6, thereby controlling the dual-mode multi-phase motor 3 to work at different voltages. The mode selector 6 can output a high level or a low level to the control system 7 according to different working conditions as the input of the control algorithm of the control system 7. A low level is output to the control system 7 under normal working conditions, and a high level is output to the control system 7 in case of failure or emergency.

[0034] Refer to Figure 3 , the mode selector 6 includes an AC-DC power supply 19, an electromagnetic coil 20, a return spring 21, and a mode selection switch 22. The AC-DC power supply 19 is connected to the grid power supply, and the electromagnetic coil 20 is connected to the AC-DC power supply 19. Under normal working conditions, when using the grid power supply, the AC-DC power supply 19 outputs a DC voltage, and the electromagnetic coil 20 is energized to make the mode selection switch 22 attracted. The mode selection switch 22 is connected to the grid power supply, and the dual-mode multi-phase motor 3 is driven by the IGBT IPM to operate the high-voltage winding 18. In case of failure and emergency working conditions, the grid power supply fails, and the battery pack power supply 5 supplies power. At this time, the electromagnetic coil 20 is de-energized, and the mode selection switch 22 is connected to the battery pack power supply 5 under the action of the return spring 21 (i.e., Figure 3Among the two lead-in wires at the uppermost part, the left one is the grid power supply, and the right one is the battery pack power supply 5). The dual-mode multi-phase motor 3 is driven by the MOSFET IPM to operate the low-voltage winding 17, pushing the actuator 14 to a preset position to achieve the fault position function. Whether operating in the high-voltage state or the low-voltage state, the power output of the dual-mode multi-phase motor 3 can be ensured.

[0035] Refer to Figure 4 、 Figure 5 , the control system 7 includes a main control chip 28, a multiplexer 24, a buffer 25, an isolation gate drive circuit 27, and a bootstrap gate circuit 26. The main control chip 28 receives signals from the mode selector 6 (that is, Figure 5 the SEL-IN port of the main control chip 28 in

[0036] receives signals). The main control chip 28 includes 6 PWM signals. The multiplexer 24 includes a multiplexer one 24a and a multiplexer two 24b. The multiplexer one 24a and the multiplexer two 24b respectively process 3 PWM signals. The PWM signals are drive instructions. The drive signals of the dual-mode multi-phase motor 3 are selected by using the multiplexer one 24a or the multiplexer two 24b. The pin SEL of the multiplexer 24 is connected to the pin SEL of the main control chip 28. The pin SEL is a selection instruction. When the main control chip 28 outputs a low level, the multiplexer two 24b outputs the PWM signal to the high-voltage drive circuit. When the main control chip 28 outputs a high level, the multiplexer one 24a outputs the PWM signal to the low-voltage drive circuit.

[0037] Refer to Figure 4 、 Figure 6, the high-voltage drive circuit (i.e., IGBT IPM) is driven by the isolated gate drive circuit 27 for isolation between the high-voltage circuit and the low-voltage circuit, and has the function of preventing the upper and lower tubes of the half-bridge from conducting simultaneously. The isolated gate drive circuit 27 includes the isolated gate drive circuit one 27a and the isolated gate drive circuit two 27b of the control U1. When the 1Y output of the buffer two 25b is at a high level and the 2Y output is at a low level, the isolated gate drive circuit one 27a outputs a high level and the isolated gate drive circuit two 27b outputs a low level. The upper arm of the U-phase half-bridge of the power drive module two 8b conducts and the lower arm cuts off. U1 is connected to the DC bus DCH+. U1 outputs a high voltage. When the 1Y output of the buffer two 25b is at a low level and the 2Y output is at a high level, the isolated gate drive circuit one 27a outputs a low level and the isolated gate drive circuit two 27b outputs a high level. The upper arm of the U-phase half-bridge of the power drive module two 8b cuts off and the lower arm conducts. U1 is connected to the DC bus DCH-. U1 outputs a low voltage. When the 1Y and 2Y outputs of the buffer two 25b are both at a high level or a low level, both the isolated gate drive circuit one 27a and the isolated gate drive circuit two 27b cut off. U1 is not connected to both DCH+ and DCH-, and U1 is in a floating state. The driving principles of V1 and W1 are the same as that of U1 ( Figure 6 The IGBT IPMs for controlling V1 and W1 are also drawn in it. However, since the principles are the same, they will not be elaborated). By reasonably arranging the output logic of U1, V1, and W1, the dual-mode multi-phase motor 3 can be driven to operate at high voltage. The output logic is shown in the following table. In the order of serial numbers 1, 2, 3, 4, 5, 6, the dual-mode multi-phase motor 3 rotates forward. In the order of serial numbers 6, 5, 4, 3, 2, 1, the dual-mode multi-phase motor 3 rotates backward.

[0038] Serial number 1Y 2Y 3Y 4Y 5Y 6Y 1 1 0 0 0 0 1 2 0 0 1 0 0 1 3 0 1 1 0 0 0 4 0 1 0 0 1 0 5 0 0 0 1 1 0 6 1 0 0 1 0 0

[0039] Refer to Figure 4 , Figure 6, the low-voltage drive circuit (i.e., MOSFET IPM) is driven by a bootstrap gate circuit 26, which has the function of preventing the upper and lower tubes of the half-bridge from conducting simultaneously. The bootstrap gate circuit 26 includes a bootstrap gate circuit one 26a that controls U2. When the 1Y output of buffer one 25a is at a high level and the 2Y output is at a low level, the HO pin of the bootstrap gate circuit one 26a outputs a high level and the LO pin outputs a low level. The upper arm of the U-phase half-bridge of the power drive module one 8a conducts and the lower arm is cut off. U2 is connected to the DC bus DCL+. U2 outputs a high voltage. When the 1Y output of buffer one 25a is at a low level and the 2Y output is at a high level, the HO pin of the bootstrap gate circuit one 26a outputs a low level and the LO pin outputs a high level. The upper arm of the U-phase half-bridge of the power drive module one 8a is cut off and the lower arm conducts. U2 is connected to the DC bus DCL-. U2 outputs a low voltage. When the 1Y and 2Y outputs of buffer one 25a are both at a high level simultaneously, the bootstrap gate circuit one 26a enters a protection state, and the HO pin and the LO pin both output low levels to prevent the upper and lower arms from conducting simultaneously (because when the output is high, the arm conducts, and when the output is low, the arm turns off. If the upper and lower arms conduct simultaneously, a short-circuit phenomenon will occur, and the voltage will flow directly from the positive pole to the negative pole. When the HO pin and the LO pin both output low levels, the upper and lower arms turn off). When the 1Y and 2Y outputs of buffer one 25a are both at a low level simultaneously, the HO pin and the LO pin of the bootstrap gate circuit one 26a both output low levels, and U2 is in a floating state (when the HO and LO are both at a low level, it is the normal operating state. When the dual-mode multi-phase motor 3 is normally driven, at a certain moment, it indeed requires the HO and LO to be both at a low level to rotate. When the HO and LO are both at a high level, it is a fault state, and the control system algorithm has a problem to enter this state. At this time, it will enter a protection state and force the output to be low to prevent the upper and lower arms of the half-bridge from conducting simultaneously and causing a short circuit). The driving principles of V2 and W2 are the same as that of U2 ( Figure 6 In the figure, the MOSFET IPMs that control V2 and W2 are also drawn. However, since the principles are the same, they will not be elaborated further). By reasonably arranging the output logic of U2, V2, and W2, the dual-mode multi-phase motor 3 can be driven to operate at a low voltage. This logic is the same as that of U1, V1, and W1.

[0040] The main control chip 28 is connected to a position detection circuit 23 that detects the position of the dual-mode multi-phase motor 3. The position detection circuit 23 is connected to a motor angle sensor and can detect the angle of the dual-mode multi-phase motor 3 in real time.

[0041] Some components in this embodiment adopt the following models.

[0042] Serial number Name Model 1 Main control chip 28 Stm32f407 2 Multiplexer 24 RS2253 3 Buffer 25 74HC245TS 4 Bootstrap gate circuit 26 IRS2101 5 Isolated gate drive circuit 27 ACPL-W314-560E 6 Power drive module two 8b FP25R12W1T7 7 Power drive module one 8a MMN200H010X

[0043] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A dual-mode electro-hydraulic actuator, characterized in that: It includes a multi-input power supply (1), a drive control unit (2), a dual-mode multi-phase motor (3), and a hydraulic system (4). The multi-input power supply (1) includes a battery pack power supply (5) and a grid power supply. The drive control unit (2) selects one of the battery pack power supply (5) and the grid power supply to drive the dual-mode multi-phase motor (3). The hydraulic system (4) includes a bidirectional hydraulic pump (9) and an actuator (14). The bidirectional hydraulic pump (9) provides hydraulic energy under the drive of the dual-mode multi-phase motor (3) to achieve the bidirectional actuation of the actuator (14). The drive control unit (2) includes a mode selector (6), a control system (7), and a power drive module (8). The power drive module (8) includes a power drive module one (8a) and a power drive module two (8b). The mode selector (6) selects one of the battery pack power supply (5) and the grid power supply and outputs it to the control system (7). The control system (7) controls the power drive module two (8b) to output a high-voltage drive circuit or controls the power drive module one (8a) to output a low-voltage drive circuit according to the selection of the mode selector (6), thereby controlling the dual-mode multi-phase motor (3) to work at different voltages. The control system (7) includes a main control chip (28) and a multiplexer (24). The main control chip (28) receives signals from the mode selector (6). The main control chip (28) includes 6 PWM signals. The multiplexer (24) includes a multiplexer one (24a) and a multiplexer two (24b). The multiplexer one (24a) and the multiplexer two (24b) process 3 PWM signals respectively. The pin SEL of the multiplexer (24) is connected to the pin SEL of the main control chip (28). When the main control chip (28) outputs a low level, the multiplexer two (24b) outputs the PWM signal to the high-voltage drive circuit. When the main control chip (28) outputs a high level, the multiplexer one (24a) outputs the PWM signal to the low-voltage drive circuit. The control system (7) includes a buffer (25). The buffer (25) includes a buffer one (25a) and a buffer two (25b). The buffer one (25a) is connected to the output of the multiplexer one (24a). The buffer two (25b) is connected to the output of the multiplexer two (24b). The control system (7) includes an isolated gate drive circuit (27). The high-voltage drive circuit is driven using the isolated gate drive circuit (27). The isolated gate drive circuit (27) includes an isolated gate drive circuit one (27a) and an isolated gate drive circuit two (27b) for controlling U1. When the 1Y output of buffer two (25b) is at a high level and the 2Y output is at a low level, the isolated gate drive circuit one (27a) outputs a high level and the isolated gate drive circuit two (27b) outputs a low level. The upper bridge arm of the U-phase half bridge of the power drive module two (8b) conducts and the lower bridge arm cuts off. U1 is connected to the DC bus DCH+. U1 outputs a high voltage. When the 1Y output of buffer two (25b) is at a low level and the 2Y output is at a high level, the isolated gate drive circuit one (27a) outputs a low level and the isolated gate drive circuit two (27b) outputs a high level. The upper bridge arm of the U-phase half bridge of the power drive module two (8b) cuts off and the lower bridge arm conducts. U1 is connected to the DC bus DCH-. U1 outputs a low voltage. When the 1Y and 2Y outputs of buffer two (25b) are both at a high level or a low level, both the isolated gate drive circuit one (27a) and the isolated gate drive circuit two (27b) cut off, and U1 is in a floating state. The driving principles of V1 and W1 are the same as that of U1.

2. The dual-mode electro-hydraulic actuator according to claim 1, wherein: The multi-input power supply (1) receives a high-voltage power input from the grid power supply and a low-voltage power input from the battery pack power supply (5). The stator of the dual-mode multi-phase motor (3) includes a low-voltage winding (17) and a high-voltage winding (18). When using the grid power supply, the high-voltage winding (18) operates, and the dual-mode multi-phase motor (3) is in a high-voltage and low-current state. When using the battery pack power supply (5), the low-voltage winding (17) operates, and the dual-mode multi-phase motor (3) is in a low-voltage and high-current state.

3. The dual-mode electro-hydraulic actuator according to claim 1, characterized in that: The mode selector (6) includes an AC-DC power supply (19), an electromagnetic coil (20), a return spring (21), and a mode selection switch (22). The AC-DC power supply (19) is connected to the grid power supply. The electromagnetic coil (20) is connected to the AC-DC power supply (19). When using the grid power supply, the AC-DC power supply (19) outputs a DC voltage, and the electromagnetic coil (20) is energized to make the mode selection switch (22) close. The mode selection switch (22) is connected to the grid power supply. When the grid power supply fails, the electromagnetic coil (20) loses power, and the mode selection switch (22) is connected to the battery pack power supply (5) under the action of the return spring (21).

4. The dual-mode electro-hydraulic actuator according to claim 1, characterized in that: The control system (7) includes a bootstrap gate circuit (26). The low-voltage drive circuit uses the bootstrap gate circuit (26) for driving. The bootstrap gate circuit (26) includes a bootstrap gate circuit one (26a) that controls U2. When the 1Y output of buffer one (25a) is at a high level and the 2Y output is at a low level, the HO pin of the bootstrap gate circuit one (26a) outputs a high level and the LO pin outputs a low level. The upper bridge arm of the U-phase half-bridge of the power drive module one (8a) conducts and the lower bridge arm cuts off. U2 is connected to the DC bus DCL+. U2 outputs a high voltage. When the 1Y output of buffer one (25a) is at a low level and the 2Y output is at a high level, the HO pin of the bootstrap gate circuit one (26a) outputs a low level and the LO pin outputs a high level. The upper bridge arm of the U-phase half-bridge of the power drive module one (8a) cuts off and the lower bridge arm conducts. U2 is connected to the DC bus DCL-. U2 outputs a low voltage. When the 1Y and 2Y outputs of buffer one (25a) are both at a high level at the same time, the bootstrap gate circuit one (26a) enters a protection state, and the HO pin and the LO pin both output a low level. When the 1Y and 2Y outputs of buffer one (25a) are both at a low level at the same time, the HO pin and the LO pin of the bootstrap gate circuit one (26a) both output a low level, and U2 is in a floating state. The driving principles of V2 and W2 are the same as that of U2.

5. The dual-mode electro-hydraulic actuator according to claim 1, characterized in that: The main control chip (28) is connected to the position detection circuit (23).

6. The dual-mode electro-hydraulic actuator according to claim 1, characterized in that: The hydraulic system (4) includes a pressurizing oil tank (10), a volume compensation valve (11), a position locking valve one (12a), a position locking valve two (12b), an overload safety valve one (13a), and an overload safety valve two (13b). The pressurizing oil tank (10) is connected to the volume compensation valve (11), the overload safety valve one (13a), the overload safety valve two (13b), and the bidirectional hydraulic pump (9). The position locking valve one (12a) and the overload safety valve one (13a) are installed on the rodless cavity oil path of the bidirectional hydraulic pump (9) leading to the actuator (14). The position locking valve two (12b) and the overload safety valve two (13b) are installed on the rod cavity oil path of the bidirectional hydraulic pump (9) leading to the actuator (14). One end of the overload safety valve one (13a) is connected to the oil path between the position locking valve one (12a) and the rodless cavity, and the other end of the overload safety valve one (13a) is connected to the pressurizing oil tank (10). One end of the overload safety valve two (13b) is connected to the oil path between the position locking valve two (12b) and the rod cavity, and the other end of the overload safety valve two (13b) is connected to the pressurizing oil tank (10).

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