What is nonlinear load?
A nonlinear load is a load whose current is not proportional to its voltage. Since some electronic components, such as transistors and diodes, exhibit nonlinear characteristics when operating, in actual power consumption, some electrical equipment connected to the load will deform the current waveform. This deformation causes the voltage to distort and generate additional frequency components, known as harmonics.
Causes of harmonics generated by nonlinear loads:
When an electronic component operates within the normal range, there is a linear relationship between its current and voltage. However, when the element enters the supersaturation or shear region, a nonlinear relationship appears. Since most electrical equipment uses AC power, and the AC signal is in the form of a sine wave, a severely distorted current waveform with many harmonic components can be obtained through the nonlinear load in the circuit.
The impact of nonlinear loads on the power system is mainly reflected in several aspects:
1. Causes distortion of the voltage or current sinusoidal waveform: Nonlinear loads have nonlinear impedance characteristics, which will cause the power drawn from the power system to cause distortion of the voltage or current waveform.
2. Generation of harmonics: Nonlinear loads will generate harmonics, which will affect the normal operation of the power system and threaten its safety and reliability. Harmonics will cause additional losses, accelerate equipment aging and reduce its lifespan, and may also cause other equipment to malfunction, causing the entire circuit system to malfunction.
3. Impact on electric energy measurement: Nonlinear loads will produce harmonics injected into the system and become harmonic sources of the system. From the analysis of the frequency response curves of inductive and electronic energy meters, its impact on electric energy measurement points out its impact on electric power. systems and electrical equipment.
4. Causes fluctuations and imbalances in the grid voltage: Nonlinear loads reduce the voltage stability of the grid, which may cause voltage fluctuations and voltage flickers, and produce negative sequence currents.
Affects the stable operation of the power system: Harmonics cause power supply voltage waveform distortion, degrade the power supply quality at the point of public connection (PCC), increase the risk of resonance, and thus threaten the safe and stable operation of the power system.
5. In order to reduce the impact of nonlinear loads on the power system, it is recommended to avoid concentrating a large number of nonlinear loads at the same power supply point and strengthen the monitoring and control of nonlinear loads.
Best Nonlinear loads harmonic solution:
Active Power Filter (Active Harmonic Filter)
