For any reactor (inductance as L) and capacitors (the capacitor for C) consisting of series LC resonant circuit, he has a fixed frequency f = 1/2π radical LC, when the external power signal equal frequency when the frequency of the resonant circuit will occur. Resonance, the inductance and capacitance on the voltage on access to the largest, and most of the sample can be equivalent to a capacitor. Based on this idea, in the series resonant circuit to provide a voltage regulator can adjust the frequency of the inverter transformer power supply, in parallel at both ends of a capacitor voltage divider for the measurement and feedback purposes, then this will constitute the set of devices. 
Product Specifications: 
1, ambient temperature: -10 ℃ ~ 45 ℃ 
2, the Working humidity: ≤ 90% 
3, altitude: ≤ 2000m 
4, power input: 380V ± 10% three-phase or 220V ± 10% single-phase (10kW below), 50Hz 
5, the rated capacity test: 0 ~ 15500kVA 
6, resonant voltage: 0 ~ 1550kV 
7, the frequency adjustment range: 0.1 ~ 300Hz 
8, the system measurement accuracy: 0.5/1.0 class 
9, frequency adjustment resolution: 0.01Hz 
10, instability: ≤ 0.05% 
11, the output waveform: sine wave 
12, waveform distortion rate: ≤ 0.5% 
13, Noise: ≤ 60dB 
14, reactor Q value: 30 ~ 120 
15, the internal net from the embedded computer program control, so the process of fully automated measurement test can also be measured manually pilot implementation, large LCD display and touch-screen characters through the USB - U disk storage and print functions, man-machine English menu display dialogue operation feature matching computer (PC machine) test monitoring and control USB communication interface and automatic test monitoring and control software. 
Constitute a set of devices 
1, frequency regulator power: it can change the output frequency, but also to change its output voltage. 
2, excitation transformers: voltage from the coupling signal and the role of transformation, and its ratio to increase voltage. 
3, reactor: with the sample in series, constitute a LC circuit. 
4, divider: test materials were used to measure the voltage on at the same time as the feedback signal to the sampling apparatus. 
5, compensation capacitors: materials used to adjust the frequency of the test.

Products based on the technology and the implementation of the standard reference 
GB2900 "electrical terminology" 
GB10229-88 "Reactor" 
DL/T596-1996 "test electrical equipment preventive point of order" 
GB/T16927.1-2-1997 "high-voltage test technique" 
ZBK41006-89 "Test Transformer" 
GB7328-87 "of transformer and reactor sound level measurement" 
IEC358 (1990) "Coupling capacitors and capacitor divider" 
IEC1000 "electromagnetic compatibility" 
GB4793-1984 safety requirements for electronic measuring instruments 
Electrical and Electronic Products GB/T2423.8-1995 basic environmental testing order 
GB1094-1-GB1094.6-96 "Level protective shell" 
GB/T3859.1-1993 semiconductor converter provides the basic requirements of 
GB/T3859.2-1993 semiconductor converter application guidelines