Adding a Variable Frequency Drive (VFD) to an existing motor application can be a quick and cost-effective way to improve system performance and efficiency. However, if not installed with the proper peripheral devices, this improvement can actually do more harm than good.
Reactors can protect both motors and variable frequency drives (VFDs) from harmful current and voltage spikes. Reactors also help reduce power line distortion, known as harmonics, by adding impedance to the power system.
Picking a passive filter solution may seem like an overwhelming task. Some manufacturers claim the only option is a low capacitance design, but at the price of performance. Our approach at TCI is to provide a wide range of solutions to cover different harmonic filtering applications, as not all passive filter designs or applications are created equal. Don’t settle on quality or performance without knowing the whole picture.
Continue reading Passive Harmonic Filter Selection GuidelinesOil field economics are changing rapidly. As a way to save money and reduce environmental impacts, many oil producers are using multi-well pad drilling as an alternative to single well sites. In 2014 over half of all new wells in unconventional fields were done using multi-pad drilling sites. Over the life of a well, different types of artificial lift equipment may be employed to maximize production. Unfortunately, with more wells, there is an increase in harmonics, and also in voltage distortion. This is presenting a problem for many multi-well pad drilling sites.
Continue reading Active Harmonic Filter saves money and time on multi-well padsIndustry standard variable speed drives, with 6‐pulse diode input rectifiers are the workhorse of industry. They are used primarily for variable speed control of ac induction motors to achieve more efficienct process control and energy savings. Industry standard three‐phase variable speed drives draw harmonic currents from the three phase voltage source. These harmonics can cause overheating and premature failure of power system equipment such as transformers, cables and circuit breakers. The harmonic currents are at higher frequencies than the 60Hz voltage supply.
Continue reading Effective Harmonic Mitigation with Active FiltersAll passive filters on the market today regardless of kVAR require capacitor disconnect contactors to be compatible with small generators at no load.
Continue reading Generator Compatibility of Passive Filters
Drive input impedance has led to considerable confusion in selecting passive filters. While most variable frequency drives (VFD) use a built-in DC choke or AC line reactor, some lower HP drives have no built-in impedance. Passive filters are an effective solution to filter harmonic currents produced by 6-pulse VFDs and reduce source current total harmonic distortion (THD) to 5% or less. The performance of all passive harmonic filters is affected by the presence or absence of impedance in the VFD.
Continue reading Drive Impedance and Passive Harmonic FiltersPower factor and harmonics are difficult problems to control simultaneously. With the use of asymmetric trap control in passive harmonic filters, both problems are resolved.
Continue reading Asymmetric Trap Control
