What are the effects of harmonics in bidirectional inverter chargers on equipment

Against the background of the rapid development of renewable energy technology and electric vehicles, Bi-directional Inverter Charger, as a key connection device between power supply and load, has been expanding its application scope. However, the accompanying harmonic problems have become increasingly prominent, posing significant challenges to the stability of the power system and the reliability of equipment.

The impact of harmonics on electrical equipment
Device overheated
The existence of harmonics will lead to an increase in the effective value of the current, which in turn will cause overheating of the equipment. Particularly in critical equipment such as transformers and electric motors, harmonic content can cause additional heat to be generated inside the equipment. Not only does this extra heat reduce the operating efficiency of the motor, it can also cause the insulation to deteriorate, shortening the life of the equipment.
Increased power loss
Harmonics cause ineffective transmission of energy and increase the overall energy consumption of the system. Specifically, the extra current caused by harmonics increases the heat generated by wires and transformers, causing additional energy losses. Not only does this reduce the overall efficiency of the system, it can also lead to higher electricity bills. For industrial users, losses caused by harmonics may account for part of their electricity bills, directly affecting the economic benefits of the enterprise.
Electrical equipment failure
Higher harmonics can cause malfunctions in electrical equipment, especially in motors and transformers. Harmonics can cause vibration and noise in equipment, increase mechanical wear, and may ultimately lead to premature equipment failure. For example, current waveform distortion caused by harmonics can cause torque fluctuations in the motor, affecting its normal operation and even causing equipment shutdown.
Shortened battery life
In a bidirectional inverter charger, the battery management system (BMS) needs to handle harmonics during charging and discharging. If the harmonic level is too high, it may cause the battery's charging and discharging process to be unstable, thus affecting the battery's cycle life and performance. When working in a high harmonic environment, the battery may be overcharged or overdischarged, accelerating the attenuation of battery capacity.
Affect equipment control system
The presence of harmonics may interfere with the equipment's control system, leading to the failure of the control strategy. For example, in a motor drive system, the controller needs to monitor current and voltage waveforms in real time. The presence of harmonics will prevent the controller from accurately judging the working status of the equipment, thus affecting the response speed and accuracy of the equipment.

Strategies for dealing with harmonics
To effectively deal with harmonic problems in bidirectional inverter chargers, relevant industries and companies can take the following measures:
Harmonic monitoring and analysis
Conduct harmonic monitoring on the system regularly to identify harmonic sources and their levels in a timely manner so that targeted control measures can be taken. The harmonic analyzer can be used to monitor current and voltage waveforms in real time and identify the frequency and amplitude of harmonics.
Apply harmonic filter
Using passive or active harmonic filters can effectively reduce the impact of harmonics and improve power quality. Passive filters are designed into resonant circuits by connecting capacitors and inductors in parallel, which can suppress harmonics at specific frequencies. The active filter monitors the current waveform in real time and generates a current waveform that is opposite to the harmonics, thereby effectively canceling the harmonic components.