The overcurrent (OC) protection limit is set usually accorging to a OC protection setting table on digital integrated protection equipment in mine explode isolation high voltage (HV) vacuum switch. For digital integra...The overcurrent (OC) protection limit is set usually accorging to a OC protection setting table on digital integrated protection equipment in mine explode isolation high voltage (HV) vacuum switch. For digital integrated protection equipment, OC protection setting table must be converted to be a microcomputer algorithm. This paper first intro-duced a method of the fitting OC protection setting table to be OC relay inverse time characteristics equations using MATLAB least square fitting. On the basis of analyzing these fitting equations, a notion, “integral limit rate” was put forward initially and a OC in-verse time digital algorithm was developed. MATLAB simulation results and a digital signal processor (DSP) based digital integrated protection equipment running test indicate that this algorithm has less calculation amount, less taking up memory, high control accuracy, implements the no-grade setting of OC delay values, suits for all kinds of low-middle mi-crocomputer system implementation.展开更多
Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synch...Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synchronous reference frame with a provision of assigning different priorities to d- and q-axes currents. During the current boosting in motoring, the d-axis current is increased by priority for a fast current response, and to minimize the overmodulation period. However in the regeneration process, the q-axis current is decreased by priority during a load reduction. Simulation and experimental results show that the proposed method, compared with the existing minimum-phase error method, is better for a fast current response, and in shortening the overmodulation period.展开更多
文摘The overcurrent (OC) protection limit is set usually accorging to a OC protection setting table on digital integrated protection equipment in mine explode isolation high voltage (HV) vacuum switch. For digital integrated protection equipment, OC protection setting table must be converted to be a microcomputer algorithm. This paper first intro-duced a method of the fitting OC protection setting table to be OC relay inverse time characteristics equations using MATLAB least square fitting. On the basis of analyzing these fitting equations, a notion, “integral limit rate” was put forward initially and a OC in-verse time digital algorithm was developed. MATLAB simulation results and a digital signal processor (DSP) based digital integrated protection equipment running test indicate that this algorithm has less calculation amount, less taking up memory, high control accuracy, implements the no-grade setting of OC delay values, suits for all kinds of low-middle mi-crocomputer system implementation.
文摘Overmodulation is frequently required during the transient interval at high speed operations of IPMSMs （interior permanent magnet synchronous motors）. In this work, an overmodulation method is developed in the synchronous reference frame with a provision of assigning different priorities to d- and q-axes currents. During the current boosting in motoring, the d-axis current is increased by priority for a fast current response, and to minimize the overmodulation period. However in the regeneration process, the q-axis current is decreased by priority during a load reduction. Simulation and experimental results show that the proposed method, compared with the existing minimum-phase error method, is better for a fast current response, and in shortening the overmodulation period.
