Dual-motor dual-input parallel driving system of compressor test bench and control method thereof

Abstract

The application relates to a double-motor double-input parallel car increasing speed driving system of a compressor test bench and a control method thereof, which comprises a transmission chain unit, an intelligent monitoring unit and an auxiliary guarantee unit. The application integrates the double-drive branch, the parallel car increasing speed gearbox, the torque detection, the auxiliary machine linkage and the independent safety protection under the same system architecture, thereby meeting the test requirements of high power, high speed and safety control. The application can significantly reduce the torque competition and load bias of the double machines, adopts a state machine control mode covering disc driving, idling, speed increasing / steady speed test and speed decreasing parking, the whole process operation logic of the test bench is clear, and the state switching is stable. Through the safety PLC, the master-slave high-speed communication and the synchronous emergency parking logic, the double-drive synchronous emergency parking can be quickly completed in a serious fault, and the residual load dangerous state of a single branch is effectively prevented.

Description

Technical Field

[0001] This invention belongs to the technical field of upgrading and transforming existing platforms of high-power compressor test equipment, specifically involving a dual-motor dual-input parallel speed-up drive system for a compressor test bench and its control method. Background Technology

[0002] Compressor test benches are used to conduct start-up, speed-up, steady-state, variable-condition, and shutdown tests on compressor test pieces under controlled intake and exhaust, lubrication and cooling, measurement and data acquisition, and safety protection conditions. As the power rating, speed range, and complexity of test conditions of the tested compressors increase, the test bench drive system not only needs to provide continuous and stable high-power drive, but also needs to maintain the safety and controllability of the shaft system during start-up, shutdown, speed-up, loading, and abnormal protection processes.

[0003] Currently, most existing compressor test benches adopt a single-motor drive structure. When the target power of the compressor test piece is increased to the level of hundreds of megawatts, the single-motor platform is difficult to meet the requirements in terms of drive capability, speed range, shaft capacity and operational redundancy. It is necessary to adopt a dual-motor cooperative drive method to obtain test capabilities with higher power levels and a wider operating range.

[0004] In a dual-motor rigid-coupled drive system, the two motors are connected to the two input shafts of a parallel gearbox, and mechanically transmit power to the same output shaft system. Existing engineering solutions often focus on the separate selection of motors, gearboxes, and auxiliary equipment, while neglecting the overall topology of the dual-input drive train, the symmetrical configuration of the two branches, the arrangement of torque and speed measurement interfaces, and the systematic integration of an independent safety stopping channel. As a result, under high-power operating conditions, risks such as unclear system boundaries, excessively long fault signal transmission links, and residual load on one branch after an anomaly in another branch can easily arise.

[0005] Meanwhile, existing dual-motor control typically includes two forms: speed servo and fixed proportional torque distribution. For dual-input parallel shaft systems with large inertia and rigid coupling, if the slave motor only passively follows the speed, torque contention, load bias, and gearbox shock are likely to occur during start-up, acceleration, load fluctuations, and state switching. If a simple fixed proportional torque setpoint is used, it is difficult to take into account the changes in operating conditions, torque feedback, and interlocking status at different test stages.

[0006] In addition, the operation of the compressor test bench includes multiple stages such as pre-start interlock confirmation, turning gear, idling, speed increase / steady speed test, speed decrease and stop, and fault protection. If any frequency converter fails, any motor fails, or key parameters exceed the limit, and the two drive units cannot be stopped synchronously without power in a very short time, the gearbox may enter a single-branch residual load state, resulting in shaft impact, increased risk to the test piece, and equipment damage. Summary of the Invention

[0007] The purpose of this application is to overcome the shortcomings of the prior art and provide a dual-motor dual-input parallel speed-increasing drive system and its control method for a compressor test bench. This system integrates the dual drive branches, parallel speed-increasing gearbox, torque measurement, auxiliary machine linkage, and independent safety protection under the same system architecture, thereby meeting the testing requirements of high power, high speed, and safe and controllable operation. At the same time, it solves the problems of uneven load distribution, dynamic torque competition, unstable state switching, and easy entry into a dangerous single-branch state during failure in the prior art.

[0008] The technical problem solved by this application is achieved through the following technical solution: A dual-motor dual-input parallel speed-increasing drive system for a compressor test bench includes a transmission chain unit, an intelligent monitoring unit, and an auxiliary support unit; The transmission chain unit includes a first drive motor, a second drive motor, a first low-speed coupling, a second low-speed coupling, a dual-input parallel speed-increasing gearbox, a high-speed coupling, a torque meter, a test compressor, and a turning unit. The first drive motor and the second drive motor are respectively connected to the two input shafts of the dual-input parallel speed-increasing gearbox via the first low-speed coupling and the second low-speed coupling. The output end of the dual-input parallel speed-increasing gearbox is sequentially connected to the high-speed coupling, the torque meter, and the test compressor. The torque meter is used to obtain the total torque information of the test shaft system. The turning unit is arranged on the dual-input parallel speed-increasing gearbox for low-speed turning before starting, shaft system inspection, and cooling turning after shutdown. The auxiliary support unit includes a lubrication / lifting / cooling unit and an interlocking unit. The lubrication / lifting / cooling unit is linked to the first drive motor, the second drive motor, the dual-input parallel speed-increasing gearbox and the torque meter, respectively. The intelligent monitoring unit includes a main frequency converter, a slave frequency converter, a main control PLC, a safety PLC / SIS, a host computer / HMI, and a high-speed master-slave communication link. The main control PLC is connected to the main frequency converter, the slave frequency converter, and the host computer / HMI to complete test task issuance, operation permit management, and routine control coordination. The high-speed master-slave communication link is used for exchanging operating status between the first drive motor and the second drive motor. The safety PLC / SIS independently receives status signals from the torque meter, including the frequency converter status, gearbox status, lubrication / lifting / cooling unit, interlocking unit, and key parameters of the compressor under test, and forms a protection judgment and action link independent of the main control link. When any critical parameter exceeds its limit, any inverter malfunctions, any branch circuit malfunctions, or any interlocking condition is not met, the safety PLC / SIS simultaneously sends an interlocking shutdown or emergency stop command to both the main inverter and the slave inverter, causing both drive motors to synchronously de-energize and stop.

[0009] Furthermore, the first drive motor, the second drive motor, and the input and output ends of the dual-input parallel speed-increasing gearbox are all equipped with speed detection interfaces or status detection interfaces, which are used to obtain the operating status of the dual branches, the working status of the dual-input parallel speed-increasing gearbox, and the parameter monitoring of the entire shaft system.

[0010] A control method for a dual-motor, dual-input parallel acceleration drive system of a compressor test bench, wherein the method is applied to the parallel acceleration drive system, and the steps of the method are as follows: S1. Control object signal acquisition, acquiring target rotational speed n Master speed feedback n1, slave speed feedback n2, master output torque T1, slave output torque T2, total torque T measured by torque meter Σ and interlock status and drive status signals; S2. Master-slave coordinated control: The master control PLC sends the target speed n to the master frequency converter. The main frequency converter handles the closed-loop speed control; the slave frequency converter handles the torque servo control, and generates the slave basic torque setpoint T based on the main unit torque reference or the actual output of the main unit. 2,base Establish a collaborative driving relationship between the two machines; S3, Torque balance correction, based on the slave's base torque T 2,base Based on this, a torque balance correction ΔT is introduced to obtain the slave torque setpoint T2. =T 2,base +ΔT, the torque balance correction amount ΔT, comprehensively utilizes the master-slave torque deviation, master-slave speed deviation, total torque deviation, and shaft system operating status for real-time correction, so that the two drive motors maintain load balance in the rigidly coupled shaft system, which satisfies the following relationship: ΔT = K1·(T1-T2) + K2·Δn + K3·(T Σ,ref -T Σ ) + K4·S; Where: K1, K2, K3, and K4 are adjustable coefficients, and T Σ,ref The target total torque is defined by S, which is a state correction term consisting of gearbox state, coupling state, lubrication state, and interlocking state. K1, K2, K3, K4 and torque change slope are set in segments under different operating states. S4, State Machine Control, includes pre-start interlock confirmation state S1, turning gear state S2, idling state S3, speed-up / speed-stabilization test state S4, and normal speed-down and stop state S5. In different states, the speed slope, torque slope, torque equalization correction weight, and protection threshold are set respectively to achieve smooth control throughout the process. S5. Graded protection and synchronous emergency stop: When different levels of anomalies are detected, a graded protection strategy is adopted. P1 indicates a minor anomaly: Execution to return to idle speed; P2 indicates a moderate anomaly: execute the return to manual check; P3 indicates a serious abnormality or a fault in any frequency converter: The safety PLC / SIS simultaneously issues a stop command to both the main frequency converter and the slave frequency converter, and confirms each other through a high-speed fiber optic communication link between the main and slave frequency converters to achieve synchronous emergency stop without power. S6. Master-Slave Switching and Fault Degradation: When the main encoder or main inverter malfunctions, but another drive channel meets the takeover conditions, the master-slave roles can be switched according to a preset switching threshold. If the switching conditions are not met, the system directly enters the hierarchical protection or synchronous emergency stop logic, thereby ensuring that protection takes precedence over continued testing. Compared with the prior art, the present invention has the following beneficial effects: 1. This invention addresses the dual-input parallel acceleration drive requirements of compressor test benches, forming a dual-motor parallel drive system architecture suitable for 100MW-class platforms, meeting the testing requirements of high-speed, high-power compressors under test.

[0011] 2. This invention integrates dual drive branches, parallel gearboxes, torque testing, auxiliary machine linkage, and independent safety chains into a unified system with clear system boundaries and strong engineering feasibility.

[0012] 3. By separating the main control link from the safety protection link, the present invention enables fault actions to be transmitted step by step without relying on conventional control loops, thereby reducing the risk of abnormal load on a single branch and delayed protection actions.

[0013] 4. This invention combines the host speed closed loop with the slave torque follow-up and introduces a torque equalization correction mechanism based on torque, speed, total torque and state variables. It is suitable for rigid coupling shaft systems of dual-input parallel gearboxes and can significantly reduce torque contention and load bias between the two machines.

[0014] 5. This invention adopts a state machine control method that covers turning gears, idling, speed increase / steady speed test, and speed decrease and stop, so that the operation logic of the test bench is clear throughout the process and the state switching is smooth.

[0015] 6. This invention, through a safety PLC, high-speed master-slave communication, and synchronous emergency stop logic, can quickly complete a dual-drive synchronous emergency stop in the event of a serious fault, effectively preventing dangerous situations caused by residual load on a single branch. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the dual-motor parallel drive system of the present invention; Figure 2 This is a schematic diagram of the system control and independent security architecture of the present invention; Figure 3 This is a schematic diagram illustrating the master-slave coordination and torque equalization control principle of the present invention; Figure 4 This is a schematic diagram of the operating status and hierarchical protection process of the present invention; Figure 5 This is a schematic diagram of the master-slave swapping and synchronization emergency stop logic of the present invention. Detailed Implementation

[0017] The present application will be further described in detail below through specific embodiments. The following embodiments are merely descriptive and not limiting, and should not be used to limit the scope of protection of the present application.

[0018] like Figure 1 As shown, a dual-motor, dual-input parallel-drive speed-increasing system for a compressor test bench is innovative in that it includes a transmission chain unit, an intelligent monitoring unit, and an auxiliary support unit. The transmission chain unit comprises a first drive motor, a second drive motor, a first low-speed coupling, a second low-speed coupling, a dual-input parallel-drive speed-increasing gearbox, a high-speed coupling, a torque meter, the compressor under test, and a turning gear unit. The first and second drive motors are respectively connected to the two input shafts of the dual-input parallel-drive speed-increasing gearbox via the first and second low-speed couplings. The output end of the dual-input parallel-drive speed-increasing gearbox is sequentially connected to the high-speed coupling, the torque meter, and the compressor under test. The torque meter is used to acquire the total torque information of the test shaft system. The turning gear unit is arranged on the dual-input parallel-drive speed-increasing gearbox for low-speed turning before start-up, shaft system inspection, and cooling turning after shutdown. The auxiliary support unit includes a lubrication / lifting / cooling unit and an interlocking unit. The lubrication / lifting / cooling unit is linked to the first drive motor, the second drive motor, the dual-input parallel speed-increasing gearbox and the torque meter, respectively. like Figure 2 As shown, the intelligent monitoring unit includes a main frequency converter, a slave frequency converter, a main control PLC, a safety PLC / SIS, a host computer / HMI, and a high-speed master-slave communication link. The main control PLC is connected to the main frequency converter, the slave frequency converter, and the host computer / HMI to complete the issuance of test tasks, operation permission management, and routine control coordination. The high-speed master-slave communication link is used for the exchange of operating status between the first drive motor and the second drive motor. The safety PLC / SIS independently receives the status signals of the frequency converter, gearbox, lubrication / lifting / cooling unit, interlocking unit, and key parameters of the compressor under test from the torque meter and forms a protection judgment and action link independent of the main control link. When any critical parameter exceeds its limit, any inverter malfunctions, any branch circuit malfunctions, or any interlocking condition is not met, the safety PLC / SIS simultaneously sends an interlocking shutdown or emergency stop command to both the main inverter and the slave inverter, causing both drive motors to synchronously de-energize and stop.

[0019] Furthermore, the first drive motor, the second drive motor, and the input and output ends of the dual-input parallel speed-increasing gearbox are all equipped with speed detection interfaces or status detection interfaces, which are used to obtain the operating status of the dual branches, the working status of the dual-input parallel speed-increasing gearbox, and the parameter monitoring of the entire shaft system.

[0020] A rigid coupling torque balancing and synchronous emergency stop control method for a dual-motor, dual-input parallel acceleration drive system of a compressor test bench, wherein the method is applied to the parallel acceleration drive system, and the steps of the method are as follows: I. Implementation Methods of Master-Slave Coordination and Torque Equalization Control like Figure 3 As shown, the main control PLC receives the target speed n given by the host computer / HMI. The torque is then sent to the main frequency converter, which generates a closed-loop speed output based on the host speed feedback. The first drive motor outputs the host torque T1, while the slave frequency converter receives the slave torque command T2. It drives the second drive motor to output slave torque T2, and the slave base torque is given by T. 2,base Based on the host torque reference or the actual output of the host, the torque balancing correction module collects the master-slave torque difference, speed deviation, total torque of the torque meter, and interlock status in real time, and calculates the correction amount ΔT to update the slave torque setpoint T2. =T 2,base +ΔT.

[0021] II. Implementation Methods of State Machine Control like Figure 4 As shown, this invention uses a state machine to organize the entire test process. After confirming all start-up conditions in state S1, it enters state S2 (turning gear); after confirming that there are no abnormalities in the axle system, it enters state S3 (idle speed) to establish a stable initial point; then it enters state S4 (acceleration / steady speed test); after the test is completed, it enters state S5 (normal deceleration and stopping). Each state corresponds to different speed slopes, torque slopes, torque equalization correction weights, and protection thresholds, thus balancing start-up smoothness and steady-state load balance.

[0022] III. Implementation Methods of Graded Protection and Synchronous Emergency Stop like Figure 2 As shown, when a minor abnormality is detected, P1 is executed to return to idle speed; when a moderate abnormality is detected, P2 is executed to return to turning gear; when a serious abnormality, any inverter failure, any motor failure, or critical parameter exceeding the limit is detected, P3 is executed to synchronously stop without power. The safety PLC / SIS simultaneously sends a stop command to the master and slave inverters and confirms the action through the master-slave high-speed communication link to shorten the fault response link.

[0023] IV. Implementation of Master-Slave Interchange like Figure 5As shown, when a fault is detected in the main encoder or the main inverter while the slave inverter is working normally, the system first determines whether the current speed, total torque and interlocking conditions meet the switching threshold. If they do, the original slave is switched to the speed control master, the original master exits the master control and enters a restricted following or no-power state as allowed. If they do not meet the requirements, the system directly enters the fault degradation or synchronous emergency stop logic.

[0024] Although embodiments and drawings of the present invention have been disclosed for illustrative purposes, those skilled in the art will understand that various substitutions, variations and modifications are possible without departing from the spirit and scope of the present invention and the appended claims. Therefore, the scope of the present invention is not limited to the contents disclosed in the embodiments and drawings.

Claims

1. A dual-motor, dual-input parallel speed-increasing drive system for a compressor test bench, characterized in that: Includes a transmission chain unit, an intelligent monitoring unit, and an auxiliary support unit; The transmission chain unit includes a first drive motor (1), a second drive motor (2), a first low-speed coupling (3), a second low-speed coupling (4), a dual-input parallel speed-increasing gearbox (5), a high-speed coupling (6), a torque meter (7), a test compressor (8), and a turning unit (10). The first drive motor (1) and the second drive motor (2) are respectively connected to the two input shafts of the dual-input parallel speed-increasing gearbox (5) via the first low-speed coupling (3) and the second low-speed coupling (4). The output end of the dual-input parallel speed-increasing gearbox (5) is sequentially connected to the high-speed coupling (6), the torque meter (7), and the test compressor (8). The torque meter (7) is used to obtain the total torque information of the test shaft system. The turning unit (10) is arranged on the dual-input parallel speed-increasing gearbox (5) for low-speed turning before starting, shaft system inspection, and cooling turning after shutdown. The auxiliary support unit includes a lubrication / lifting / cooling unit (9) and an interlocking unit (15). The lubrication / lifting / cooling unit (9) is linked with the first drive motor (1), the second drive motor (2), the dual-input parallel speed-increasing gearbox (5), and the torque meter (7), respectively. The intelligent monitoring unit includes a main frequency converter (11), a slave frequency converter (12), a main control PLC (13), a safety PLC / SIS (14), a host computer / HMI (16), and a master-slave high-speed communication link (17). The main control PLC (13) is connected to the main frequency converter (11), the slave frequency converter (12), and the host computer / HMI (16) to complete the issuance of test tasks, operation permission management, and routine control coordination. The master-slave high-speed communication link (17) is used for the exchange of operating status between the first drive motor (1) and the second drive motor (2). The safety PLC / SIS (14) independently receives the status signals of the frequency converter status, gearbox status, lubrication / lifting / cooling unit (9), interlocking unit (15), and key parameters of the tested compressor (8) from the torque meter (7) and forms a protection judgment and action link independent of the main control link. When any critical parameter exceeds the limit, any inverter fails, any branch fails, or any interlock condition is not met, the safety PLC / SIS (14) simultaneously sends an interlock stop or emergency stop command to the main inverter (11) and the slave inverter (12) to make the two drive motors stop synchronously.

2. The compressor test bench dual-motor dual-input parallel speed-increasing drive system according to claim 1, characterized in that: The first drive motor (1), the second drive motor (2), and the dual-input parallel speed-increasing gearbox (5) are all equipped with speed detection interfaces or status detection interfaces at their input and output ends, which are used to obtain the running status of the dual branches, the working status of the dual-input parallel speed-increasing gearbox, and the parameter monitoring of the entire shaft system.

3. A control method for a dual-motor, dual-input parallel speed-increasing drive system for a compressor test bench, characterized in that: The method is applied to the parallel acceleration drive system as described in any one of claims 1 and 2, and the steps of the method are as follows: S1. Control object signal acquisition, acquiring target rotational speed n Master speed feedback n1, slave speed feedback n2, master output torque T1, slave output torque T2, total torque T measured by torque meter Σ and interlock status and drive status signals; S2. Master-slave coordinated control: The master control PLC sends the target speed n to the master frequency converter. The main frequency converter handles the closed-loop speed control; the slave frequency converter handles the torque servo control, and generates the slave basic torque setpoint T based on the main unit torque reference or the actual output of the main unit. 2,base Establish a dual-machine collaborative driving relationship; S3, Torque balance correction, based on the slave's base torque T 2,base Based on this, a torque balance correction ΔT is introduced to obtain the slave torque setpoint T2. =T 2,base +ΔT, the torque balance correction amount ΔT, comprehensively utilizes the master-slave torque deviation, master-slave speed deviation, total torque deviation, and shaft system operating status for real-time correction, so that the two drive motors maintain load balance in the rigidly coupled shaft system, which satisfies the following relationship: ΔT = K1·(T1-T2) + K2·Δn + K3·(T Σ,ref -T Σ ) + K4·S; Where: K1, K2, K3, and K4 are adjustable coefficients, and T Σ,ref The target total torque is defined by S, which is a state correction term consisting of gearbox state, coupling state, lubrication state, and interlocking state. K1, K2, K3, K4 and torque change slope are set in segments under different operating states. S4, State Machine Control, includes pre-start interlock confirmation state S1, turning gear state S2, idling state S3, speed-up / speed-stabilization test state S4, and normal speed-down and stop state S5. In different states, the speed slope, torque slope, torque equalization correction weight, and protection threshold are set respectively to achieve smooth control throughout the process. S5. Graded protection and synchronous emergency stop: When different levels of anomalies are detected, a graded protection strategy is adopted. P1 indicates a minor anomaly: Execution to return to idle speed; P2 indicates a moderate anomaly: execute the return to manual check; P3 indicates a serious abnormality or a fault in any frequency converter: The safety PLC / SIS simultaneously issues a stop command to both the main frequency converter and the slave frequency converter, and confirms each other through a high-speed fiber optic communication link between the main and slave frequency converters to achieve synchronous emergency stop without power. S6. Master-slave switching and fault degradation: When the main encoder or main inverter is abnormal but another drive channel has the conditions to take over, the master-slave role can be switched according to the preset switching threshold. When the switching conditions are not met, the system directly enters the hierarchical protection or synchronous emergency stop logic, thereby ensuring that protection takes precedence over continuing the test.

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