270kVA/270kV Variable Frequency Series Resonance Test Device


 




I. Test Object and Test Requirements



1. AC withstand voltage test for 35kV/300mm2 cable of 1km, capacitance ≤0.1945uF, test frequency 30-300Hz, test voltage 52kV, test duration 60min. 270kVA/270kV Variable Frequency Series Resonance Test Device (35kV cable 1km, 110kV cable 0.2km)



2. AC withstand voltage test for GIS, switches and other substation equipment of 110kV and below, test frequency 30-300Hz, test voltage not exceeding 265kV, test duration 1min.



3. AC withstand voltage test for 110kV/63000kVA main transformer, capacitance ≤0.02uF, test frequency 45-65Hz, test voltage not exceeding 160kV, test duration 1min.



4. AC withstand voltage test for 110kV/300mm2 cable of 0.2km, capacitance ≤0.0294uF, test frequency 30-300Hz, test voltage 128kV, test duration 60min.



5. AC withstand voltage test for 10kV/300mm2 cable of 3km, capacitance ≤1.126uF, test frequency 30-300Hz, test voltage 22kV, test duration 5min. 270kVA/270kV Variable Frequency Series Resonance Test Device (35kV cable 1km, 110kV cable 0.2km)



II.Working Environment



1.     Ambient temperature: -100C –500C;



2.     Relative humidity: ≤90%RH;



3.     Altitude:   ≤1000m;



III.Main Technical Parameters and Functions of the Device



1.       Rated capacity: 270kVA;



2.       Input power: single-phase 220V or three-phase 380V, frequency 50Hz;



3.       Rated voltage: 45kV; 90kV; 135kV; 270kV;



4.       Rated current: 6A; 3A; 2A; 1A;



5.       Working frequency: 30-300Hz;



6.       Output waveform: sine wave



7.       Waveform distortion rate: output voltage waveform distortion rate ≤1%;



8.       Working time: continuous 60min allowed at rated load; 1.1 times overvoltage for 1 minute;



9.       Temperature rise: after continuous operation for 60min at rated load, temperature rise ≤65K;



10.  Quality factor: device's own Q≥30 (f=45Hz);



11.  Protection functions: overcurrent, overvoltage and flashover protection for the test object (see variable frequency power supply section for details);



12.  Measurement accuracy: system effective value class 1.5;



IV.Standards Followed by the Equipment



GB10229-88            "Reactors"



GB1094　　　　　　　　"Power Transformers"



GB50150-2006　　　　　"Standard for Hand-over Test of Electric Equipment in Electrical Equipment Installation Engineering"



DL/T 596-1996          "Preventive Test Code for Electric Power Equipment"



GB1094.1-GB1094.6-96   "Degrees of Protection Provided by Enclosures"



GB2900　　　　　　　　"Electrotechnical Terminology"



GB/T16927.1~2-1997　　 "High-Voltage Test Techniques"



V.Determination of Device Capacity



Design six reactors, each reactor is 45kVA/45kV/1A/110H, total device capacity is 270kVA.



Verification: 1. AC withstand voltage test for 35kV/300mm2 cable of 1km, capacitance ≤0.1945uF, test frequency 30-300Hz, test voltage 52kV, test duration 60min.



Use two reactors in series (coefficient 1.1) and three groups in parallel, then L=110×2×1.1/3=80.67H, then:



Test frequency: f=1/2π√LC=1/(2×3.14×√80.67×0.1945×10-6)=40.18Hz



Test current: I=2πfCU试 =2π×40.18×0.1945×10-6×52×103=2.55A



2. AC withstand voltage test for 110kV/300mm2 cable of 0.2km, capacitance ≤0.0294uF, test frequency 30-300Hz, test voltage 128kV, test duration 60min. 270kVA/270kV Variable Frequency Series Resonance Test Device (35kV cable 1km, 110kV cable 0.2km)



Use three reactors in series (coefficient 1.2) and two groups in parallel, then L=110×3×1.2/2=198H, then:



Test frequency: f=1/2π√LC=1/(2×3.14×√198×0.0294×10-6)=66Hz


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