تجزیه و تحلیل عملکرد از ژنراتور MHD دیسک Ar-CS در مقیاس تجاری مربوط به سیستم برق با ژنراتور سنکرون

Performance analyses of a commercial scale closed-cycle MHD disk generator are performed. A large scale MHD generator, superconducting magnet, inversion system and synchronous generator are designed. The MHD generator is operated with Ar–Cs plasma and connected to the ac power infinite bus through line-commutated inverters, while the synchronous generator is operated in parallel. The thermal input is 1000 MW, and the power output is 400 and 200 MW, from the MHD and synchronous generators. Fault analyses have found that rather large fluctuations within the MHD generator are induced by faults of the inverter and power transmission line, but control of the inverters can recover the MHD generation system to normal operation within 0.15 s. The feature of behavior of the MHD generator is the same with or without the parallel operation of the synchronous generator. The interaction between the MHD and the synchronous generators is small, and this feature is much different from the open-cycle MHD generation system, since the variation of output current of the closed-cycle disk MHD generator is much smaller compared with open-cycle MHD generators.

The behaviors of closed-cycle MHD generators are much different from those of open-cycle MHD generators, and therefore, the interaction between a closed-cycle MHD generator and an ac power system through the inversion system must be studied independently of open-cycle MHD generators. MHD power generation is a combined system, where the MHD and synchronous generators are operated in parallel, and therefore, the interaction between these generators must also be studied. The closed-cycle MHD generator is operated with He or Ar, and the basic characteristics of these kinds of plasma are similar, but the behaviors of MHD generators are different from each other from the viewpoint of the time constant and ionization instabilities. Both MHD generators operated with He or Ar must also be studied independently. There are two types of inverters, i.e. line-commutated inverters and forced-commutated inverters, and they have different characteristics. How the behaviors of a commercial scale closed-cycle MHD disk generator operated with Ar–Cs and connected with the ac power system through line-commutated inverters are different from the pilot plant scale disk generator is one of the important items for commercialization of closed-cycle MHD generators. Several studies of the behaviors of MHD generators connected with the ac power system through inverters have already been reported for the open-cycle MHD generators [1], [2] and [3] and closed-cycle disk MHD generators [4], [5] and [6], showing very important features of the interconnection of the MHD generator and the ac power system. This paper treats the behaviors of a closed-cycle MHD disk generator of commercial scale, operated with an Ar–Cs nonequilibrium plasma and connected with the ac power system through line-commutated inverters in parallel operation with a synchronous generator. The thermal input is assumed to be 1000 MW, which is 10 times larger than the pilot plant scale MHD generator [5] and [6], and the power output is 400 MW and 200 MW from the MHD generator and synchronous generator, respectively. Basic designs and nominal operation is described first, then fault analyses are performed, and finally, the effects of parallel operation of the synchronous generator is examined.

Performance analyses of a commercial scale closed-cycle disk MHD generator are performed. The following results have been obtained: 1. The large scale MHD generator, superconducting magnet, inversion system and synchronous generator are designed. The MHD generator is operated with an Ar–Cs plasma and connected to the ac power infinite bus through line-commutated inverters, while the synchronous generator is operated in parallel. The thermal input is 1000 MW, and the power output is 400 MW from the MHD generator and 200 MW from the synchronous generator. 2. Fault analyses are performed. Rather large fluctuations of various quantities in the MHD generator are induced by faults of the inverters and power transmission lines, but control of the inverters can recover the MHD generation system to normal operation within 0.15 s after the fault. The feature of behavior of the MHD generator is the same with or without the parallel operation of the synchronous generator. 3. The effects of the single line ground fault and the three-line ground fault on the MHD generator are almost the same, although the magnitude and period caused by the three-phase fault are larger and longer. On the other hand, the effects of the single line ground fault and the three-phase line ground fault on the synchronous generator are much different, and the three-phase fault results in a larger disturbance on the synchronous generator. 4. It is found that the interaction between the MHD generator and the synchronous generator is small, and this feature is much different from that of the open-cycle MHD generator, since the variation of output current of the closed-cycle disk MHD generator is much smaller compared with open-cycle MHD generators.