There are a number of electrical devices that have nonlinear operating characteristics i.e even when applied voltage is sinusoidal in nature, the current drawn by the device is non-sinusoidal in nature. These nonlinear devices used in power distribution circuits create nonlinear currents and which subsequently causes voltage distortions. These nonlinear currents and voltages have been generally referred to as harmonic currents and voltages. The proliferation of electronic switching devices in modern equipment has resulted in a significant increase in the amount of harmonic pollution in the electrical distribution systems. These harmonics if disregarded or undetected may cause harmonic resonant conditions, which could present system operating problems resulting in complaints from customers and reduced life of power equipment as well as degraded efficiency and performance. Harmonic currents and voltages can cause many unfavourable effects on the power system itself and the connected loads. Malfunctioning of electronic equipment, capacitor failure, transformer and neutral conductor over overheating, excessive heating in rotating machinery are some of these effects.   The Background Zhenjiang Naisi New Material Co., Ltd. is mainly engaged in the production and sales of new ultra-hard composite wear-resistant cutting wires, photovoltaic wire cutting wheel recycling coating process processing, production of steel cords, technical services and testing services for the above products, self-operated and acting for the import and export business of various commodities and technologies (except for commodities and technologies that are restricted by the state or prohibited from import and export), sales of silicon materials.   The PQ Problem Due to the Harmonic Voltage and Harmonics Current in the old factory building of the customer, the capacitors are often damaged, so the need for harmonic mitigation is generated.   The YT Solution In view of the high current distortion rate (High THDi)and voltage distortion rate(THDv) in the field, installing an Active Harmonic Filter at the low-voltage side can reduce Current Harmonics (THDi) and Voltage Harmonics accordingly.   The Performance There are some harmonic problems in Building 3 of Shanghai Tongren Hospital. In order to avoid the impact of harmonics on the normal work of the hospital, a Active Harmonic Filter is installed to control the harmonics.After AHF installation, the field harmonic problem has been well improved, and the current distortion rate is reduced from about 30% to about 1.5%. The harmonics include the 3rd, 5th, and 7th harmonics, and the 5th harmonic is the most serious. After the Active Harmonic Filter is installed, the waveforms are close to standard sine waves, and after compensation, the harmonic current content is significantly reduced, achieving a perfect compensation effect.     The Picture   Click here to view more applications.  

In today’s world, where industries rely heavily on electronic equipment and non-linear loads, maintaining power quality has become a critical concern. Poor power quality can lead to inefficiencies, equipment damage, and increased operational costs. One of the most effective solutions to address power quality issues, particularly harmonic distortion, is the use of Active Harmonic Filters (AHFs). In this blog, we’ll explore what an Active Harmonic Filter is, how it works, its benefits, and why it’s an essential component of modern power quality solutions.   Understanding Harmonics and How They Affect Things Understanding what harmonics are and why they are troublesome is crucial before delving into Active Harmonic Filters. Electrical waveform distortions known as harmonics are turned on by non-linear loads like computers, LED lights, variable frequency drives (VFDs), and other electronic equipment. These loads produce harmonic frequencies that are multiples of the basic power frequency (50 Hz or 60 Hz) by drawing current in brief pulses as opposed to a smooth sinusoidal wave.   Harmonics can cause several issues, including:   Overheating of equipment: Harmonics increase the RMS current, leading to excessive heat in transformers, motors, and cables. Voltage distortion: Harmonics can distort the voltage waveform, affecting the performance of sensitive equipment. Power losses: Increased harmonic currents result in higher energy losses and reduced system efficiency. Nuisance tripping: Harmonics can cause circuit breakers and protective devices to trip unnecessarily. Interference: Harmonics can interfere with communication systems and other electronic devices. To mitigate these issues, harmonic filters are used. Among the various types of filters available, Active Harmonic Filters are considered one of the most advanced and effective solutions.   What is an Active Harmonic Filter?   An Active Harmonic Filter (AHF) is an electronic device designed to mitigate harmonic distortion in electrical systems. Unlike passive filters, which use passive components like capacitors and inductors to block or absorb harmonics, AHFs use power electronics to actively inject counter-harmonic currents into the system. This cancels out the harmonic currents generated by non-linear loads, resulting in a cleaner and more stable power supply. How Does an Active Harmonic Filter Work?   The operation of an Active Harmonic Filter can be broken down into the following steps: Monitoring the Load Current: The AHF continuously monitors the load current using sensors. It analyzes the waveform to detect harmonic frequencies. Harmonic Detection: Using advanced algorithms and digital signal processing (DSP), the AHF identifies the harmonic components present in the load current. Generating Counter-Harmonics: The AHF generates harmonic currents that are equal in magnitude but opposite in phase to the detected harmonics. Injecting Counter-Har...