电传动推土机牵引性能匹配的变压控制方法

电传动推土机动力总成包括发动机、发电机、超级电容以及轮边驱动电机,其载荷变化范围大且具有突变性的动力学特征,使发电机与电动机难以实现全局功率匹配.针对电传动推土机动态牵引性能匹配这一关键问题,提出基于双DC-DC(直流-直流)变换器的直流母线电压变压控制方法.即在直流母线与发电机之间加入DC-DC变换器,控制发电机的额定电压工作点,实现发动机在额定工况点工作的高效目标;在直流母线与电动机之间加入DC-DC变换器,根据实时载荷所表达的系统状态变矢量调节变压系数,控制发电机与电动机相对于载荷变化的动力学匹配关系,使发电机与电动机在全载荷意义上实现功率匹配,保证其牵引性能的发挥.通过某型号推土机开发过程性能匹配及其系统数字化模型仿真试验,验证了基于双DC-DC变换器的直流母线电压变压控制方法的有效性.

Voltage Transformation Control Method for Traction Dynamic Characteristic Match of Electric Drive Bulldozer

The power assembly of electric drive bulldozer consists of engine, generator, super capacitor and direct wheel drives motors. The extensive-change and mutability load characteristic leads to the hardness for the generator and the motors to achieve power matching on the whole-load. To solve the key problem of the traction dynamic characteristic match of electric drive bulldozer, a voltage transformation control method for direct current bus voltage based on double DC-DC converters was raised in this paper. The method is to add a DC-DC converter between the generator and the direct current bus, which can control the rating voltage work point of the generator, to realize the high-efficient objective of the engine working on the rating work condition point; and to add a DC-DC converter between the direct current bus and the motor, which can regulate the voltage transformation coefficient according to the system state variant vector expressed by real-time load, to control the dynamics matching relationship of the generator and the motors when the load varies, to realize the power matching between the generator and the motors in a whole-load sense, and guarantee the traction characteristic to be unleashed. The validity of the voltage transformation control method for direct current bus voltage based on double DC-DC converters is proved, through the developing performance matching and the digital emulation model of some model bulldozer. A new control method is proposed for commercial developing the electric drive bulldozer.