考虑牵引所多运行状态的城轨交直流供电计算

城市轨道牵引变电所存在多种运行状态:整流状态、整流机组关断状态、逆变回馈装置恒定电压运行状态、逆变回馈装置最大功率运行状态.针对潮流计算中牵引变电所状态的不确定而影响计算收敛性的问题,提出一种考虑牵引变电所多运行状态的城轨交直流供电计算算法.该算法对逆变回馈装置和车载制动电阻建模,根据迭代过程中牵引变电所网压、电流,采用滞环比较策略确定牵引变电所状态,通过交直流交替迭代方法求解潮流.对某地铁工程进行仿真分析和实测验证,结果表明:仿真与实测的牵引变电所负荷过程曲线Pearson相关系数为0.76～0.92;逆变回馈装置节能率的仿真结果与实测误差不超过1.7%;在全线整流机组空载电压较高的场合,当逆变回馈装置的启动电压设置在1 750 V以上时,消耗在车载制动电阻上的能量显著增大.

Calculation of Urban Rail AC/DC Power Supply with Traction Substation in Multi-Operation Modes

Traction substations operate in such modes as the rectification, rectifier turn-off, constant voltage operation of inverting-feedback devices, and maximum-power operation of inverting-feedback device. To achieve convergence in power flow calculation when the states of traction substations are uncertain, a calculation algorithm for urban rail AC/DC power supply is proposed while it considers the multi-operation states of traction substation. As for this algorithm, the inverting-feedback devices and onboard resistors on trains are modeled. According to the network voltage of the traction substation in the iterative process, the state of traction substation is determined by hysteretic comparison strategy, and the power flow is solved by AC/DC alternating iteration method. The simulation and field tests of a subway project show that the Pearson correlation coefficient between the simulated and measured load process falls between 0.76 and 0.92; and the errors between the simulation and measured energy-saving rate of the inverting-feedback devices are not more than 1.7%. In the case of high no-load voltage of substations in DC traction power supply system, when the starting voltage of the inverting feedback device is set above 1750 V, the energy consumed by the on-board braking resistor is significantly increased.