The narrow-gauge wired locomotive is an important traction power equipment widely used in the fields of underground railways and industrial and mining excavation projects. It often faces specific engineering practices such as frequent load changes, large fluctuations in power supply, and poor working environment (vibration, humidity, corrosion, etc.). The problem, in view of the above problems and needs, comprehensively consider the advantages and disadvantages of current mainstream AC drive control methods, taking into account engineering practicability and technological advancement, research and propose an improved slip frequency control method with large torque output and busbar The voltage compensation and heavy-duty torque compensation measures were designed, and the simulation and experimental research were carried out.
System structure and working principle: The drive system is mainly composed of three parts: power circuit, system control circuit and protection circuit.
The main power circuit is mainly composed of a surge suppression link, a DC side filter capacitor, a brake module, a three-phase inverter bridge and a buffer absorption circuit. After the wired DC voltage is filtered, the control circuit controls the power tube of the three-phase inverter bridge to output the positive current through the pulse width modulation signal, and drags the motor to run; the surge suppression link prevents the startup surge from impacting, and the braking module realizes The effective braking of the locomotive and the buffer absorption circuit are used to reduce the electrical stress of the power switch tube and ensure the stable operation of the inverter bridge. The system control circuit is composed of an auxiliary power supply circuit, a digital control circuit and a drive circuit. Auxiliary power circuit filters and stabilizes the line voltage.
Pressure, voltage division, high frequency conversion, transformer processing and other links provide various levels of DC power for the control circuit; digital control circuit realizes comprehensive analysis of signals, control algorithm and user interface design; drive circuit realizes six-tube circuit IGBT device Drive processing. Protection monitoring includes current, voltage, and temperature protection circuits. The current protection circuit is a detection and protection circuit for the stator current of the motor; the voltage protection circuit refers to the detection, protection and related compensation of the DC side voltage; the temperature protection circuit detects and protects the temperature of the inverter base to avoid abnormality of the inverter caused by overheating.
