电传动推土机牵引性能匹配的变压控制方法

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

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.

The power assembly of electric drive bulldozer consists of an engine, a generator, a super capacitor and direct wheel drive motors. The extensive-change and mutability load characteristic makes it hard 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 （direct current-direct current） converters was proposed 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 lead, 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 was proved, through the developing performance matching and the digital emulation model of some model bulldozer.