1 / 30

HT-7

HT-7. ASIPP. The Design and Analysis of Poloidal Field Grid Power Supply System of HT-7 Superconducting Tokamak. L.W.Xu et al., Institute of Plasma Physics, Chinese Academy of Sciences, P.R.China. HT-7. ASIPP. Outline. Introduction The parameter selection of PF grid

lelia
Download Presentation

HT-7

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. HT-7 ASIPP The Design and Analysis of Poloidal Field Grid Power Supply System of HT-7 Superconducting Tokamak L.W.Xu et al., Institute of Plasma Physics, Chinese Academy of Sciences, P.R.China

  2. HT-7 ASIPP Outline • Introduction • The parameter selection of PF grid • power supply system • The design of reactive compensation • and harmonic suppress • Experiment results analysis

  3. HT-7 ASIPP Introduction In past experiments, the electric power which the PF coils in HT-7 tokamak were supplied by a 120MW ac flywheel generator. Because the ac flywheel generator was in idling at most times, so the ratio of electric utility is very lower. In the meantime, we found that it has the disadvantage of large noise, complex operation, difficult maintenance and high cost (about 6000 RMB a day) .Based on the actual running parameters of HT-7 PF and the capacity of our transformer substation , we puts forward a new project – PF grid power supply system to replace ac flywheel generator power supply system . Through two experiment campaigns of 2001-2002 d 2002-2003, the running results Show that this project satisfied the requirements of HT-7 experiment and criterions

  4. HT-7 ASIPP The parameter selection of PF grid power supply system 1. Parameter selection of three-winding transformer The HT-7 PF includes two parts: OH heating field (HF) and EF vertical field (VF), The HF is supplied by two rectifiers in series, and the VF is supplied by one rectifier. Because the ac flywheel generator outputs 6 phases that their phasic difference is 300, so the converter transformer is adopted reverse-three-winding-transformer. In the experiments of HT-7, the current of HF and VF are IP/80+0.5 and 0.031×Ip (KA) respectively, where Ip (KA) is the discharge current of plasma. Because Ip is less than 200KA in most experiments, so we take 200KA as the maximum current of plasma. When the output voltage of ac flywheel generator is 1700V, the maximum dc output voltage of HF rectifier and VF rectifier are 668V and 438V. In actual experiment, when IP ≤ 200KA, the trigger angle αof HF rectifier and

  5. HT-7 ASIPP VF rectifier are more than 500 and 400 respectively. So the required dc output voltage of HF rectifier and VF rectifier are UdHF=668×cos500=430V. UdVF＝438×cos400=336V. Fig .1 Connection diagram of PF power supply system

  6. HT-7 ASIPP We take α=150 when dc output voltage of HF rectifier and VF rectifier are 430V and 336V , so the maximum dc output voltage (α=00) of them are 445V and 348V. and the secondary line voltage of rectifier transformer can be obtain: U2HF＝165 V U2VF＝258 V Through above analysis and based on the turn ratio of rectifier transformer, the primary line voltage is: U1HF＝165×6.875＝1134 V U1VF＝258×5.24＝1351V In order to satisfy the requirement of HF and VF simultaneously, So the parameter of three-winding transformer is selected as U2=1400 V S=5 MVA Uk=5 %

  7. HT-7 ASIPP 2. Capacity calculation of HT-7 PF power supply system The maximum dc output voltage (α=00) of HF and VF are 550V and 360V respectively. According to the design parameters of PF, the resistance of HF coil and VF coil is 35mΩ. Based onthis data, the active power, reactive power and total capacity of PF can be calculated. Fig .1 is the curves of PF power versus IP variation, when IP=200KA, the active power, reactive power and total capacity of PF are 1.66MW, 3.4MVAR,and 3.78MVA respectively. QC is the reactive compensation capacity when the power factor is compensated to 0.8.

  8. HT-7 ASIPP Fig .2 the curve of PF power versus IP P－active power (MW) Q－reactive power (MVAR) S－total capacity (MVA) QC－reactive compensation capacity (0.8) (MVAR)

  9. HT-7 ASIPP The design of reactive compensation and harmonic suppress 1.Harmonic current calculation of PF power supply system Because the OH HF and EF VF coils are large inductance loads, the current waveform of rectifier transformer secondary coil is square wave. According to connection diagram of Fig .1, the HF current IHF that injects to three-winding transformer is a two-step-ladder wave . Through the Fourier series analysis, the PF current wave can be expressed as:

  10. HT-7 ASIPP 2. Parameter design of reactive and harmonic compensation From above analysis, we know that PF power supply system inject large reactive power and harmonic current, so the measurements must be taken to suppress these reactive and harmonic. In the design of this device, we adopted fixed LC filter to compensate reactive power and suppress harmonic current. Because the impedance and frequency of grid may be fluctuated in the actual running, and it perhaps get rise to parallel resonance, therefore, a resistance must be added to the filter branch to suppress the harmonic over-voltage.According to Fig. 2, the required compensation capacity is about 1MVar if the power coefficient is compensated to 0.8, so we take 1.2Mvar as the compensation capacity.

  11. HT-7 ASIPP If the resistance is increased, the harmonic enlarge times can be limited in a lower value, and the resonance is suppressed, on the other hand , this can result in a worse filter characteristic, so we must consider two factors to reach a satisfied effect. The parameter of filter are Total compensation capacity : 1.2MVar Phase capacity: 200KVar ( each branch of 5th and 7th 100KVar 5th branch parameter: C5＝393.175μF L5＝1.032 mH R5＝32Ω (Q=20) 7th branch parameter: C7＝393.175μF L7＝0.526 mH R5＝23Ω (Q=20)

  12. HT-7 ASIPP Fig .3 Connection diagram of filter

  13. HT-7 ASIPP 3. The device of PF grid power supply system

  14. HT-7 ASIPP

  15. HT-7 ASIPP

  16. HT-7 ASIPP Experiment results analysis Through 2001-2002 and 2002-2003 two experiment campaigns, the PF grid power supply system satisfied the requirement of HT-7 experiment completely. From the analysis of acquired waves, it obtain the anticipated effect.

  17. HT-7 ASIPP

  18. HT-7 ASIPP

  19. HT-7 ASIPP

  20. HT-7 ASIPP

  21. HT-7 ASIPP

  22. HT-7 ASIPP 1. The analysis of harmonic current and voltage in 10KV Fig. 3 PF harmonic current analysis diagram when I P =143KA

  23. HT-7 HT-7 ASIPP ASIPP Table1 harmonic current value (10KV)

  24. HT-7 ASIPP When harmonic current is injected 10KV grid, it can produce harmonic voltage because of grid impedance. This harmonic voltage may bring harm to other user. So the harmonic voltage must be limited. Fig. 4 Harmonic voltage analysis diagram (10KV)when I P =199KA

  25. HT-7 ASIPP Table 2. Harmonic voltage coefficient ( 10KV)

  26. HT-7 ASIPP 2.The analysis of voltage drop ratio Fig. 5 PF grid power supply distribution diagram

  27. HT-7 ASIPP Table 3 . The voltage drop ratio (10KV)

  28. HT-7 ASIPP 3. The analysis of capacity, active power, reactive power and power factor Fig. 6 The voltage and current curve when IP=199KA

  29. HT-7 ASIPP Fig. 7 The curve of capacity, active power, reactive power and power factor versus IP

  30. Thank You!

More Related