A hybrid series-parallel electromechanical composite transmission system bench test platform

Abstract

The application discloses a hybrid series-parallel electromechanical composite transmission system bench test platform, and relates to the technical field of hybrid electric vehicles.The bench test platform comprises a coupling mechanism, a power source, a dynamometer and a control system.The power source comprises an engine, a first permanent magnet synchronous motor and a second permanent magnet synchronous motor.The power source and the dynamometer are connected with the coupling mechanism, and the torque of the power source drives the dynamometer through the coupling mechanism.The power source is also connected with the control system, which is used to calculate the driving torque and the vibration compensation torque according to the controller instruction and the sensing information collected by the speed and torque sensor, and drive the power source to operate according to the driving torque and the vibration compensation torque.The application can verify the control effect of various control strategies, and has good use value.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hybrid electric vehicles, and particularly relates to a hybrid series-parallel electromechanical composite transmission system bench test platform. BACKGROUND

[0002] Electromechanical composite technology can significantly improve vehicle fuel economy, power performance and emission performance, and has attracted the attention of many scholars, research institutions and vehicle manufacturers in various fields at home and abroad. The demand for environmentally friendly hybrid power systems is increasing, leading to the development of advanced energy management and coordinated control algorithms to maximize fuel economy and reduce pollutant emissions. Through research on numerous energy management strategies based on optimization algorithms, it is found that due to the high computational complexity, they can only be in the theoretical research stage and are difficult to use for real-time control. At the same time, current research on electromechanical composite technology is more focused on structural design matching, energy management and power coordination control. With the increasing maturity of electromechanical composite technology, the quality of vehicle travel has also received increasing attention. While people are pursuing the improvement of power performance and economy, the demand for ride comfort is also gradually increasing, and research on transmission system vibration control has become increasingly important. Currently, torsional vibration of the transmission system has become one of the important factors hindering the development of high-speed, precision and lightweight vehicles. Controlling the torsional vibration of the transmission system is a problem that must be faced and urgently solved in the design of electromechanical composite transmission systems.

[0003] Currently, there are many theoretical achievements in the fields of hybrid power, power coordination and active vibration control. However, due to the complexity of the system and the high real-time requirements of the control algorithm, there are many difficulties in verifying the algorithm, which affects the engineering application potential of electromechanical composite control algorithms. SUMMARY

[0004] The purpose of the present application is to provide a hybrid series-parallel electromechanical composite transmission system bench test platform to verify the control effect of various control strategies, which has good use value.

[0005] To achieve the above purpose, the present application provides the following solutions:

[0006] A hybrid series-parallel electromechanical composite transmission system bench test platform, comprising: a coupling mechanism, a power source, a dynamometer and a control system; the power source comprises an engine, a first permanent magnet synchronous motor and a second permanent magnet synchronous motor;

[0007] The power source and the dynamometer are connected with the coupling mechanism, and the torque of the power source drives the dynamometer through the coupling mechanism;

[0008] The power source is also connected with the control system, and the control system is used for calculating driving torque and vibration compensation torque according to controller instruction and sensing information collected by the rotation speed torque sensor, and driving the power source to operate according to the driving torque and the vibration compensation torque.

[0009] According to the specific embodiments provided by the application, the following technical effects are disclosed.

[0010] The hybrid mechanical-electric compound transmission system test platform provided by the application comprises three power sources, namely one engine and two motors, the engine and the motors are controlled by corresponding engine controllers and motor controllers, and the whole test platform is controlled by a vehicle controller. BRIEF DESCRIPTION OF DRAWINGS

[0011] In order to more clearly illustrate the technical solutions in the embodiments of the application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments. Obviously, the drawings in the following description only constitute some embodiments of the application, and for those skilled in the art, other drawings can also be obtained from these drawings without creative labor.

[0012] Figure 1 The structure diagram of the hybrid mechanical-electric compound transmission system test platform provided by the application is shown in the figure.

[0013] Figure 2 The vehicle speed following curve is shown in the figure.

[0014] Figure 3 The engine speed curve is shown in the figure.

[0015] Figure 4 The motor A (i.e. the first permanent magnet synchronous motor) speed curve is shown in the figure.

[0016] Figure 5 The motor B (i.e. the second permanent magnet synchronous motor) speed curve is shown in the figure.

[0017] Figure 6 The coupling mechanism output torque curve is shown in the figure.

[0018] Figure 7 The engine torque curve is shown in the figure.

[0019] Figure 8 The motor A torque curve is shown in the figure.

[0020] Figure 9 The motor B torque curve is shown in the figure.

[0021] Figure 10This is a schematic diagram of the battery's SOC curve;

[0022] Figure 11 This is a schematic diagram showing the distribution of engine operating points;

[0023] Figure 12 This is a schematic diagram showing the distribution of the operating points of motor A;

[0024] Figure 13 This is a schematic diagram showing the distribution of the operating points of motor B;

[0025] Figure 14 This is a time-domain schematic diagram of the output shaft torque under active control.

[0026] Figure 15 This is a time-domain schematic diagram of the output shaft torque without active control.

[0027] Figure 16 This is a frequency domain diagram of the output shaft torque under active control.

[0028] Figure 17 This is a frequency domain diagram of the output shaft torque without active control. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] The purpose of this invention is to provide a test platform for a hybrid electromechanical transmission system to verify the control effects of various control strategies.

[0031] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0032] like Figure 1 As shown, the hybrid electromechanical composite transmission system test platform provided by the present invention is characterized by comprising: a coupling mechanism, a power source, a dynamometer, and a control system.

[0033] The power source includes an engine, a first permanent magnet synchronous motor (i.e., motor A), and a second permanent magnet synchronous motor (i.e., motor B).

[0034] The control system includes: a vehicle controller and an engine controller, a first motor controller (i.e., motor A controller), a second motor controller (i.e., motor B controller), and a dynamometer controller connected to the vehicle controller.

[0035] The power source and the dynamometer are connected with the coupling mechanism, and the torque of the power source drives the dynamometer through the coupling mechanism. The dynamometer is used as the load of the system, simulates the driving resistance, and applies the resistance torque to the system.

[0036] The power source is also connected with the control system, and the control system is used for calculating the driving torque and the vibration compensation torque according to the control instruction and the sensing information collected by the speed and torque sensor, and driving the power source to operate according to the driving torque and the vibration compensation torque.

[0037] The engine controller is used for driving the engine to operate according to the control instruction.

[0038] The first motor controller is used for calculating the driving torque and the vibration compensation torque of the first permanent magnet synchronous motor according to the control instruction and the sensing information collected by the speed and torque sensor, and driving the first permanent magnet synchronous motor to operate according to the driving torque and the vibration compensation torque of the first permanent magnet synchronous motor.

[0039] The second motor controller is used for calculating the driving torque and the vibration compensation torque of the second permanent magnet synchronous motor according to the control instruction and the sensing information collected by the speed and torque sensor, and driving the second permanent magnet synchronous motor to operate according to the driving torque and the vibration compensation torque of the second permanent magnet synchronous motor.

[0040] The dynamometer controller is used for driving the dynamometer to operate according to the control instruction.

[0041] Specifically, the engine controller, the motor controller and the dynamometer controller are connected with the vehicle controller through the CAN bus. The speed and torque sensor is connected between the engine, the motor and the dynamometer and the coupling mechanism, and is used for recording the change of the torque on the transmission shaft. Meanwhile, the torque signal of the speed and torque sensor is transmitted to the motor controller through the signal conversion chip, and is used as the feedback signal of the vibration active control. The vibration active control algorithm is integrated in the motor controller, and the vibration compensation torque is calculated in the motor controller according to the feedback signal of the speed and torque sensor and the control instruction sent by the vehicle controller. The motor controller drives the motor to operate according to the control instruction of the vehicle controller, so that the motor generates the driving torque. Meanwhile, the vibration active control algorithm is integrated in the motor controller, receives the signal of the speed and torque sensor, calculates the vibration compensation torque in the motor controller according to the feedback signal, and drives the motor to generate the vibration compensation torque. The vibration compensation torque and the driving torque are added to form the final motor torque, and the motor is driven to operate.

[0042] The hybrid mechanical-electric composite transmission system test bench platform further comprises a power battery pack connected with the first permanent magnet synchronous motor and the second permanent magnet synchronous motor.

[0043] The working principle of the hybrid mechanical-electricity composite transmission system test bench platform is as follows: the host computer applies instructions to the vehicle controller (RapidECU) through USB CAN. The vehicle controller sends control instructions to the engine controller and the motor controller through the CAN line, and drives the power source to run by the bottom layer controllers. At the same time, the bottom layer sensors also feedback the test bench running state information to form a closed loop control. The sensor signals are recorded and stored by the LMS data acquisition system. The key components in the hybrid mechanical-electricity composite transmission system test bench will be introduced below.

[0044] 1) Engine

[0045] The engine in this embodiment is a turbocharged diesel engine, which is the main power source. At the same time, the engine is also the main excitation source of system vibration. The main performance parameters of the engine are shown in Table 1.

[0046] Table 1 Basic performance parameters of diesel engine

[0047] Item Value Unit Rated power 120 kW Rated speed 2300 r / min Maximum torque 700 N·m Maximum torque speed 1650 r / min Cylinder number 4 - Stroke number 4 - Stroke 130 mm Displacement 4.76 L Bore 108 mm

[0048] 2) Power battery pack

[0049] In this embodiment, Samsung INR21700-50E cells are used, and the nominal voltage of a single cell is 3.63V. 96 single cells (6 series and 16 parallel) form a module, and the finished battery is composed of 16 modules. A battery box contains 8 modules, and the whole power battery pack is composed of two battery boxes and a high-voltage control box. The nominal voltage of the whole power battery pack is 345.6V, and the battery capacity is 80Ah. The battery pack parameters are shown in Table 2.

[0050] Table 2 Battery pack design parameters

[0051] Item Parameter Battery cell type Samsung INR21700-50E Grouping method 96S16P Grouping nominal voltage 345.6V Grouping nominal capacity 80Ah Rated discharge current 80A Maximum discharge current 160A / 60S Charging current 20A System total energy 27.648kWh Working environment temperature -20～60(℃)

[0052] 3) Permanent magnet synchronous motor and controller

[0053] The two motors in the test bench platform are four-quadrant permanent magnet synchronous motors with the same power and model, and the rated power is 60kW and the reference speed is 2600r / min. The basic parameters of the motor are shown in Table 3.

[0054] Table 3 Basic parameters of motor

[0055] Item Value Unit Rated power 60 kW Peak power 110 kW Peak torque 400 N·m Reference speed 2600 r / min Maximum speed 5500 r / min

[0056] The motor controller is a D-type motor controller produced by Beijing Qi'an Electrical Technology Co., Ltd. The basic parameters of the motor controller are shown in Table 4. The motor controller includes an ARM chip and a DSP chip, wherein the ARM chip is mainly responsible for the external function development of the controller, including analog, digital signal acquisition and processing, CAN communication, 485 communication processing, etc., and the DSP is mainly responsible for motor drive control. In this embodiment, in order to ensure that the vibration active control can respond quickly, the vibration active control algorithm is integrated into the ARM chip of the motor controller. The control program development uses software Keil uVision4, and C language is used to add a vibration control program between the received CAN torque instruction and the instruction sent to the DSP chip. After the code program is compiled, it is burned into the ARM chip through the ULINK2 emulator.

[0057] Table 4 Basic parameters of D-type motor controller

[0058] Item Value Unit Rated power 100 kW Peak power 250 kW Rated output current AC 210 A Short-time working current AC 520 A Rated condition controller efficiency ≥98％ -

[0059] 4) Coupling mechanism

[0060] The coupling mechanism used in this embodiment retains its power split and continuous transmission ratio characteristics. By changing the position of the output, different gear positions are switched, thereby omitting the gear shifting clutch device.

[0061] 5) Dynamometer

[0062] A CW440-type eddy current dynamometer produced by Luoyang Nanfeng Mechanical and Electrical Equipment Co., Ltd. is used in this embodiment to apply a load to the system. The maximum power is 440kW, the maximum current is 23A, and the highest speed is 6500r / min. The dynamometer can realize constant speed control or constant torque control, and the speed and torque values are displayed in real time. The loading torque can be adjusted through the knob on the control console, or the dynamometer speed or torque can be controlled through the external control box.

[0063] The test verification results and analysis of the hybrid mechanical and electrical composite transmission system bench test platform provided by the application are as follows:

[0064] 1) Energy management strategy test

[0065] The energy management strategy is verified in the EVT2 mode. The simulation results and experimental results of the energy management strategy are compared and analyzed under specific cycle conditions. The fuel economy experiment is shown in Table 5, wherein the "target" value represents the simulation result, and the "actual" value represents the experimental result. Due to the difference between the simulation model precision of the dual-mode hybrid mechanical and electrical composite transmission and the actual engine and motor system characteristics in the test bench, the actual value and the target value of the fuel economy of the dual-mode hybrid mechanical and electrical composite transmission vehicle exist differences.

[0066] Table 5 Fuel economy test results

[0067]

[0068] The characteristic curves of each component of the dual-mode series-parallel electromechanical hybrid transmission are shown in Figure 2-Figure 17 Figure 2 is the vehicle speed following curve, which is calculated from the measured output speed of the coupling mechanism, and Figure 2 It can be seen that the actual vehicle speed can track the target vehicle speed well. Figure 3 , Figure 4 and Figure 5 are the engine speed, motor A speed and motor B speed, respectively, and Figure 3-Figure 5 It can be seen that the actual value and the target value have the same trend of change. The same control command can be accurately transmitted in the simulation process, while the network-oriented control based on the CAN communication transmission of the instruction in the test platform has packet loss, delay and numerical conversion, etc., resulting in differences between the actual value and the target value.

[0069] Figure 6-Figure 9 are the coupling mechanism output torque, engine torque, motor A torque and motor B torque, respectively, and Figure 6-Figure 9 It can be seen that the actual output torque characteristics of the coupling mechanism are basically the same as the target torque characteristics, and fully meet the system power demand. The control strategy makes the engine torque more stable, and the torque range of motor A and motor B larger, which is conducive to adjusting the engine operating point and improving fuel economy. Figure 10 is the battery SOC curve, and Figure 10 It can be seen that the target value and the actual value can both maintain a good balance of SOC. Figure 11-Figure 13 are the engine, motor A and motor B operating point distribution diagrams, respectively. The engine and motor operating points are mostly distributed in the high efficiency interval, which is conducive to improving fuel economy. The target value and the actual value are very close, thus verifying the effectiveness of the energy management strategy.

[0070] 2) Active vibration control algorithm test

[0071] ​In the hybrid mechanical-electric composite transmission system bench test platform, only the steady state operation condition of the system is tested for active control. An adaptive filter is constructed to identify the transmission system model of the secondary path offline, and to improve the control effect as much as possible under the premise of ensuring stable control. The test work shown in the application is in the EVT2 mode. The average torque of the system output is stabilized at 300 N·m, and the control effect of the vibration active control is tested when the engine, the vibration source of the system, is working at 1200 r / min and 1400 r / min respectively. The average torque of the motor A and B is determined by the vehicle control strategy. The vibration active control algorithm runs in the motor controller, and the transmission shaft torque is actively suppressed by controlling the torque of the motor A and B.

[0072] The torque of the output shaft with and without active control is compared as shown in Table 5. Figure 14-Figure 15 It can be seen that at different speeds, the active control algorithm can significantly reduce the amplitude of torque fluctuation. Due to the existence of a large number of unstable factors in the actual bench test platform, the control effect fluctuates slightly, but still has obvious vibration suppression effect. The mean square difference of the torque on the transmission shaft with and without active control is compared as shown in Table 6.

[0073] Table 6 Comparison of torque mean square difference of output shaft before and after active control

[0074]

[0075] The torque frequency domain of the output shaft with and without active control is compared as shown in Table 7. Figure 16-Figure 17 It can be seen that when the engine speed is 1200 r / min, the vibration components on the transmission shaft are mainly 1 times and 2 times of the engine rotation frequency (20 Hz and 40 Hz), and when the engine speed is 1200 r / min, the vibration components on the transmission shaft are mainly 23 Hz and 47 Hz, which are also 1 times and 2 times of the engine rotation frequency respectively. It can be seen that it is reasonable to take the multiples of the engine rotation frequency as the active control object. From Figure 16-Figure 17 It can be seen that after applying active control, the amplitude of the 1 times and 2 times of the engine rotation frequency components on the transmission shaft has decreased significantly, verifying the effectiveness of the active control in the hybrid mechanical-electric composite transmission system bench test platform.

[0076] Each embodiment in the specification is described in a progressive manner, and each embodiment focuses on the difference from other embodiments. The same or similar parts between each embodiment can be referred to each other.

[0077] The principles and implementation manners of the present application are described by using specific examples in the present application, and the above examples are only used to help understand the method of the present application and its core idea; meanwhile, for the general technical personnel in the art, the specific implementation manners and application range will be changed according to the idea of the present application. In conclusion, the content of the present specification should not be understood as the limitation of the present application.

Claims

1. A test platform for a hybrid electromechanical composite transmission system, characterized in that, include: The system includes a coupling mechanism, a power source, a dynamometer, and a control system; the power source includes an engine, a first permanent magnet synchronous motor, and a second permanent magnet synchronous motor; a speed and torque sensor is connected between the power source and the coupling mechanism, and between the dynamometer and the coupling mechanism, and the speed and torque sensor is used to record the current torque of the power source and the dynamometer; Both the power source and the dynamometer are connected to the coupling mechanism, and the torque of the power source drives the dynamometer together through the coupling mechanism; The power source is also connected to the control system, which is used to calculate the driving torque and vibration compensation torque according to the controller command and the sensing information collected by the speed and torque sensor, and drive the power source to run according to the driving torque and vibration compensation torque. The control system includes: a vehicle controller and an engine controller, a first motor controller, a second motor controller, and a dynamometer controller connected to the vehicle controller; The vehicle controller is used to send control commands to the engine controller, the first motor controller, the second motor controller, and the dynamometer controller; The engine controller is used to drive the engine to operate according to the control commands; The first motor controller is used to calculate the driving torque and vibration compensation torque of the first permanent magnet synchronous motor according to the control command and the sensing information collected by the speed and torque sensor, and drive the first permanent magnet synchronous motor to run according to the driving torque and vibration compensation torque of the first permanent magnet synchronous motor. The second motor controller is used to calculate the driving torque and vibration compensation torque of the second permanent magnet synchronous motor according to the control command and the sensing information collected by the speed and torque sensor, and drive the second permanent magnet synchronous motor to run according to the driving torque and vibration compensation torque of the second permanent magnet synchronous motor. The dynamometer controller is used to drive the dynamometer to operate according to the control instructions; The engine controller, the first motor controller, the second motor controller, and the dynamometer controller are connected to the vehicle controller via a CAN bus; The first permanent magnet synchronous motor and the second permanent magnet synchronous motor are four-quadrant permanent magnet synchronous motors with the same power and model, with a rated power of 60kW and a reference speed of 2600r / min.

2. The test platform for the hybrid electromechanical composite transmission system according to claim 1, characterized in that, Also includes: A power battery pack connected to the first permanent magnet synchronous motor and the second permanent magnet synchronous motor.

3. The test platform for the hybrid electromechanical composite transmission system according to claim 1, characterized in that, The dynamometer is a CW440 eddy current dynamometer with a maximum power of 440kW, a maximum current of 23A, and a maximum speed of 6500r / min.

Images