The vehicle rolling test machine plays a crucial role in traction and electric braking characteristics testing. By simulating real-world operating conditions, it provides a controllable and repeatable testing environment for performance verification, parameter optimization, and fault analysis of the vehicle's traction and electric braking systems. It is an indispensable key piece of equipment in the R&D and maintenance of rail transit equipment.
During traction characteristics testing, the vehicle rolling test machine simulates vehicle running resistance through its drive system, enabling the test vehicle to achieve traction conditions similar to those on actual tracks on rollers. During the test, the test machine precisely controls roller speed, load torque, and track excitation, while simultaneously collecting parameters such as traction motor current, voltage, speed, and vehicle acceleration. This simulation method not only avoids data interference from random operating conditions (such as wind speed and grade variations) during line testing, but also allows targeted testing of vehicle performance under varying traction requirements by adjusting the roller friction coefficient or applying additional loads. For example, this allows verification of traction motor output stability under rated power and overload conditions.
Electric braking characteristics testing is another core function of the vehicle rolling test machine. When the vehicle enters the braking phase, the test machine simulates the train's kinetic energy through a dynamometer motor, converting the feedback energy generated by electric braking into electrical energy and feeding it back into the power grid for efficient energy utilization. During this process, the test machine monitors key indicators such as brake resistor temperature, regenerative braking current waveform, and braking distance in real time, assessing the coordination between the electric braking system and the air brake. For example, by setting different braking deceleration commands, the test machine can verify the braking force distribution logic of the electric brake in high-speed and low-speed ranges, ensuring vehicle safety during emergency braking or downhill conditions.
The vehicle rolling test machine demonstrates unique advantages in combined traction and electric braking testing. Traditional line testing struggles to precisely control both traction and braking parameters simultaneously. However, the test machine, through a multi-microcomputer networked control system, achieves synchronized regulation of traction motor output torque and electric brake regenerative power. This combined testing capability enables R&D personnel to analyze energy flow, motor efficiency changes, and control system response speed during the traction-braking transition, providing data support for optimizing vehicle power matching strategies. For example, in EMU cascade testing, the test machine can simulate traction/braking command transmission delays in multi-car formations to verify braking consistency across the entire vehicle.
The test machine's modular design further expands its application scenarios in traction electric brake testing. By replacing roller units or adjusting the track gauge, the same device can adapt to vehicles with different wheelbases and track gauges, meeting the testing needs of various types of rail transit equipment, including subways, urban rail transit, and EMUs. Furthermore, the test machine's hydraulic excitation system simulates track irregularities and, combined with traction/braking conditions, replicates the vehicle's dynamic response under complex track conditions, providing a comprehensive test platform for evaluating bogie stability, wheel-rail relationship, and ride comfort.
During the R&D phase, the vehicle rolling test machine accelerates iterative optimization of traction electric brake systems through parametric testing. Engineers can adjust PID parameters, braking curve slope, or energy management strategies in the control algorithm based on test data, shortening development cycles. During maintenance, the test machine can retest the performance of vehicles after replacing the traction motor or brake resistor, ensuring that repair quality meets standards. For example, after a certain type of subway vehicle is repaired, the test machine verifies whether the electric brake regenerative efficiency meets standards, avoiding the risk of rework.
The vehicle rolling test machine, with its high-precision simulation, multi-operating condition coverage, and data acquisition capabilities, has become a core piece of equipment for traction electric braking characteristic testing. It not only improves test efficiency and result reliability, but also provides strong technical support for rail transit vehicle powertrain design, control strategy development, and lifecycle maintenance.
