kWHFWelderTechnicalProposal.docx

1、kWHFWelderTechnicalProposal Technical ProposalforStraight Seam Welding Pipe Production Line100kW Solid State WelderCATALOGUE1. Technical Instructions 11.1 Features of new generation H.F. solid state welder 11.2 Model instructions for solid state H.F. welder 11.3 Working principle of solid state H.F.

2、 welder 11.4 Technical parameters of 100kW solid state H.F. equipment 41.5 Core technical instructions of control and protection 61.6 Main parts list for solid state H.F. welder 62. Composing and Brief Introduction for Solid State H.F. Welder 72.1 Equipment composing 72.2 Brief introduction for soli

3、d state H.F. welder 73. Supply List 94. Requirements for Equipment Using 104.1 Environment requirements 104.2 Power net requirements 105. Supplying scope 115.1 Supplying scope for supplier 115.2 Supplying scope for user 116. Technical Documents Delivery 117. Installation and Commissioning 121. Techn

4、ical Instructions1.1 Features of new generation H.F. solid state welder 1.1.1 The solid state H.F. welder adopts Germany IXYS company IXFN38N100Q2 38A/1000V high-power MOSFET and DSEI 261-12B 60A/1200V rapid recovery diode to compose series type invertible circuit. 1.1.2 The solid state H.F. welder

5、adopts modularization design with more compact structure which makes maintenance and high-power realization much easier.1.1.3 It has particular technology of bridge-divided over-current protection that guarantees equipment safety.1.1.4 It combines international advanced control method of same produc

6、ts, adopts advanced technologies like fixed angle phase-locking control, upper frequency limit/lower frequency limit lock-lost protection and etc. With these technologies, the equipments run more stably, more efficiently, more accurate and effective protections to the inductor short-circuit and open

7、-circuit malfunction during pipe welding production.1.1.5 Speed-power closed-loop control system which is an optional installation to user, it highly improves welding efficiency and reduces technics adjustment period. 1.1.6 Line-in end of solid state H.F. welder does not need step-up /step-down rect

8、ifier transformer, compared with vacuum tube welder and parallel type welder; it has significant energy-saving effects (Under same welding condition, energy-saving 30% compared with vacuum tube welder). 1.2 Model instructions for solid state H.F. welder1.3 Working principle of solid state H.F. welde

9、r Solid state H.F. welder main circuit structure is as follows fig.1; it is a typical AC-DC-AC variable frequency structure. Rectifier adopts 3-phase bridge style thyristor phase-control rectifier circuit, DC side adopts inductor, capacitor to compose LC filter which meet the working requirements of

10、 voltage type inverter. The voltage type inverter adopts modularization parallel structure to extend power supply power, each inverter module is single phase MOSFET bridge style circuit connected with series resonance tank circuit by H.F. matching transformer. On one hand, the matching transformer r

11、ealizes power combination and impedance matching; on the other hand it realizes electric isolation of load and power supply. To put effective and swift protection on over-current malfunction of voltage type inverter, our company introduces special and stable over-current protection circuit which gua

12、rantees safe and stable running of inverter.Fig 1 Circuit structure of solid state H.F. welderVoltage type resonance inverter also called series connection type resonance inverter is the most critical part of the whole solid state H.F. power supply; fig 2 shows the structure, output voltage and curr

13、ent wave of inverter module. By controlling connection and disconnection alternatively of MOS 1&3, MOS 2&4, the series connection type inverter output voltage uH is close to square-wave, due to the inverter output voltage frequency is near by resonance frequency of resonance tank circuit, and now th

14、e inverter output voltage fundamental wave from resonance tank circuit to inverter has the minimum impedance value, the maximum impedance value to other high harmonics, therefore load current iH is close to sine waveform.Fig 2 Voltage type resonance inverter circuit structure and output waveformSeri

15、es connection resonance inverter typical working state can be divided into three types: sensibility, resistive leakage, capacitive. Fig 3 shows separately the three working status inverter output voltage, current and experiment waveforms.（a）small sensitivity status （b）small capacitive status （c）resi

16、stive leakage statusFig 3 Series connection resonance inverter output waveformsWhen series connection resonance inverter works at small sensitivity status (fig 3a), inverters working frequency is higher than inherent resonance frequency of resonance tank circuit a little bit, i.e. load current iH la

17、g to load voltage uH a electric angle. Now current-exchange of inverter has several features: 1) Parts startup is zero voltage (ZVS), zero current (ZCS), theoretically the wastage of the parts startup is zero; 2) Parts shutdown is zero voltage, non-zero current, but due to small current when parts s

18、hutdown, plus zero voltage current-exchange (ZVS), so parts shutdown wastage is small too; 3) circuit stray inductance has small effect on inverter current-exchange; 4) current-exchange has no requirement on backward recovery features of inverse parallel diode, the parts suffer very small surge impa

19、ct when current-exchanging. When series connection resonance inverter works at capacitive status (fig 3b), inverters working frequency is lower than inherent resonance frequency of resonance tank circuit a little bit, i.e. load current iH advance to load voltage uH a electric angle. Now current-exch

20、ange of inverter has several features: 1) Parts shutdown is zero voltage (ZVS), zero current (ZCS), theoretically the wastage of the parts shutdown is zero; 2) Parts startup is high voltage, large current, so parts startup wastage is very big; 3) circuit stray inductance has strong effect on inverte

21、r current-exchange; 4) backward recovery current of inverse parallel diode of MOS yield strong voltage current oscillation, the parts suffer very strong surge impact when current-exchanging, it threatens power part safety running severely. When series connection resonance inverter works at resistive

22、 leakage status (fig 3c), its working frequency equals inherent resonance frequency of resonance tank circuit, i.e. load current iH has the same phase position with load voltage uH. Theoretically the resistive leakage status is the best working status, but actually due to the effects of dead zone pe

23、riod and resistance & capacitance absorption circuit, inverter current-exchange parts working status is not in good condition, also load fluctuation makes inverter deviate to capacitive working status easily, it threatens stable and safe running of inverter. From the analysis above we know that the

24、best working status of series connection resonance inverter is small sensitivity standard resonance status. Our companys solid state H.F. power supply controls circuit by accurate fixed angle phase-lock which makes inverter reaches the best working state. Besides, compared with other companys parall

25、el connection resonance H.F. power supply, our companys series connection resonance H.F. power supply parts not only has small switch wastage and high power supply efficiency, but also has much better protection to various malfunctions of resonance tank circuit. 1.4 Technical parameters of 100kW sol

26、id state H.F. equipment1.4.1 Designed parametersNominal power: 100kWRated DC power: Pd=120kWRated DC voltage: UdN=450VRated DC current: IdN=270AThe whole efficiency: 85%Output power: Pout100kWDesigned frequency: f=400450kHzMOSFET inverter: 60kW2Tank circuit output mode: no welding transformer output

27、, secondary resonance1.4.2 Power distribution requirementsNominal power: 100kWRated DC power: Pd=120kWLine-in power factor: COS0.85Power distribution capacity: S140kVAPower supply voltage: 3-phase 380V/50HzLine-in current: I=220ALine-in cable: each phase adopts 95mm2 copper cable parallel connection

28、s, 3-phase 4-line1.4.3 Circulation soft water cooling system (air-water cooling system, GPKL-0.35）Cooling capacity: 30100kcal/hOutlet temperature: 40Working flux: 12m3/hWorking pressure: 0.15MpaWater tank capacity: 320LRated power: pipe pump motor 2.2kW, spray pump motor 0.75kW, fan motor 0.37kWRate

29、d power: 3-phase 380V/50HzNoise: 85dBWith water tank level indication and temperature display, low water level andover-temperature protection functionDimension: 158011301960mm1.5 Core technical instructions of control and protection1.5.1 Solid state H.F. welder adopts the most advanced fixed-angel p

30、hase-locking control technique, inverter working status do not change as load tank circuit change, which keep the work at the best small sensitivity resonance status all the time, welder works stably with high efficiency.1.5.2 Solid state H.F. welder has advanced functions like high/low lock-lost pr

31、otection, frequency upper limit/lower limit protection, invert over-current, tank circuit over-voltage and etc. Also more accurate and efficient on open-circuit, short-circuit, arcing of inductor malfunction, it guarantees welder stable running.1.5.3 Besides regular protections, each inverter bridge

32、 adopts multiple protections, such as DC side over-current, AC side over-current, AC side over-voltage and etc. It realizes protection redundancy, guarantees inverter safe running. 1.5.4 Rectifier side control circuit adopts singlechip technology which solves automatic phase-recognize successfully, i.e. no requirements on 3-phase power supply input line; thyristor trigger circuit adopts all digital equal interval triggering, it reduces non-characte