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What is harmonic filter
Harmonic filter uses an array of capacitors, inductors and resistors harmonic currents are directed to the ground. Hrfyltr harmonics can be formed from many elements, each of which is used to transfer the land harmonic multiples.
How to select the right harmonic reactor
It is essential that the current THD reactor installed in the networks of more than 10% or more than 3% THD voltage (ie without capacitors). In such cases it is necessary to observe the following points: 1. If the current third harmonic is more than 20% of the fifth harmonic, the third harmonic reactors (P = 14%) are used. Otherwise the fifth harmonic reactors (P = 7% or P = 5.67%) will be used.2. In the case of the fifth harmonic reactors if the voltage THD is less than 7% of the reactor 7% and 5.67% if more reactors are used. 3. The installation of capacitors in series with the reactor, the voltage on the capacitor will be equal to: (Uc = U / (1 - P) It should be noted that the rated voltage of the capacitor used in the reactor circuit is always greater than nominal voltage network. Designed to achieve the resonant frequency, the capacitor must be registered with the capacity of the reactor or in the catalog indicated.
Advantages of reactors, harmonic elimination
The advantages of eliminating harmonic reactors include the following: 1. reduce the current at the time of switching capacitor banks2-reduction capacitor caused by harmonics 3. Reduce the heat generated in the cable 4. Reduce the heat generated in Transformers 5-life capacitors 6. Remove voltage waveform distortion 7. prevent unreasonable performance protective circuits
Choose a suitable reactor
The capacitor and reactor systems is very important for proper operation. To achieve the best results, it is essential to observe the following points: 1. The resonant frequency of the series should be selected based on harmonic analysis system.2-for property reactor inductive voltage of the power supply voltage network Dvsrkhazn more. Therefore, the voltage on the resonant frequency occurs. 3. Due to higher voltage than the grid voltage inductive property reactor, can be created in different branches of the series with the capacitor. In order to achieve the desired power capacity must be improved. 4. Use the following flowchart resonant frequency can be selected:
5. The voltage across the capacitor will be equal to: (Uc = U / (1-P After selecting the resonant frequency, the following tables corresponding capacitance is determined.
Highlights in the use of reactors, harmonic elimination
1-capacitor and reactor must be consistent with the capacitance is exactly equivalent to the amount listed in the table 2-reactors produce a lot of heat should be at altitudes above capacitors and preparing for them is anticipated.(3) between the reactors and body panels, as well as between two reactor minimum distance of 5 to 7 inches to be considered.