In fact, as the graphic below indicates, the use of an optimized layout and carefully constructed transformer design actually offered better EMI performance than the 66-kHz design. This website uses cookies to improve your experience while you navigate through the website. It is vital to have a clear understanding in these concepts in order to excel in such fields. The basic idea here is that your switcher is going to generate noise at the switching frequency and at harmonics of the switching frequency. The switching frequencies tend to be greater than 4 kHz with a required fundamental frequency of up to 300 Hz and higher. Fax: +44 (0)118 981 2002 The higher switching frequency of the 132-kHz design used the same size core with fewer turns. Why? But opting out of some of these cookies may affect your browsing experience. Frequency divided by the fundamental frequency a 4 kHz switching frequency, 60 Hz in United! A seven-level hybrid inverter configuration with fundamental harmonic elimination switching scheme have been presented in [2]. The first 66-kHz version matches the number of turns of the 132-kHz version (pink). The volume reduction in power converters over the past several decades can chiefly be attributed to increases in switching frequency. By clicking Accept All, you consent to the use of ALL the cookies. Well even conduct a complimentary test on your material to ensure that our sensors will both detect it accurately and that it will integrate well into your environment.Simply let us know what youre looking to do, and well be in touch to assist! Radiated and conducted EMI (see Fig. The computation algorithm for SHE conventionally requires huge calculation time to identify switching angles of the inverter and hence a truth table based modulation is applied for . For Phase A: If V control > V triangle then V ao = V d/2. This is a measurement of the speed of the sensor and how quickly it can take readings in your production environment. The present work focuses on the control of the voltage source inverter, which feeds the ac machine of the drive system with variable-frequency, switched voltage waveforms. Harmonic currents occur at frequencies in multiples of the fundamental frequency, 60 Hz in the United States. To find out more see our Cookie Policy, High performance ZVS buck regulator removes barriers to increased power throughput in wide input range point-of-load applications, The PI33XX: zero-voltage switching applied to buck regulation. repeats itself (goes through its cycle) 100 times each second. Here we see that the core temperature of the 132-kHz design was 12.2C lower than the 66-kHz design. Music, this benefit does not hold true and why engineers can even efficiency. Harmonics are voltages or currents that operate at a frequency that is an integer (whole-number) multiple of the fundamental frequency. Together with a few clicks of the systems actually had an intuitive meaning! The lower number of turns drives down dc-resistance (Rdc). It consists of a signal (C) at the carrier wave frequency f C, with the modulation contained in narrow frequency bands called sidebands (SB) just above and below the carrier. Each term in the series is referred to as a harmonic of the fundamental frequency. The frequency of carrier signal establishes the switching 1. Below are just some of the many sensors we offer with rapid sensor switching frequencies. The Reactance of this inductor (L Henry) is given by 2*pi* (n*f)*L, where f is the fundamental frequency and n is the order of harmonic. A sine wave or square wave oscillator is usually used to convert the rectified, or battery dc voltage to a higher frequency. The fundamental is at the same frequency as the square wave, and each odd harmonic is an odd multiple of the fundamental frequency. One of the more specific advantages of understanding and measuring sensor switching frequency is that it allows you to identify the smallest possible target that can be seen on a line and determine the distance between two separate readings. 1. As the motor output frequency increases, the impact of the VFD switching frequency becomes more pronounced. These companies need industrial sensors to verify a number of different production requirements: These medical products are small, and when theyre moving at very high line speeds, only an automated sensor and one with a high sensor switching frequency is going to be able to verify and capture the information these companies need to ensure their production processes are running smoothly. The highest frequency that is an oscillating sine wave of 100 Hz ( many years ago we called it cycles-per-second! You must Sign in or This switch is added to allow energy stored in this inductor to be used for zero-voltage switching. Cmpurile obligatorii sunt marcate cu *. One of the more specific advantages of understanding and measuring sensor switching frequency is that it allows you to identify the smallest possible target that can be seen on a line and determine the distance between two separate readings. Moving to a higher switching frequency, however, can also be viewed as an opportunity for the designer to use fewer turns, in order to reduce flux density and therefore help efficiency. To determine what switching frequency would work best for your application, it is important to look at the advantages and disadvantages as the switching frequency is increased. The effects of switching frequency on power loss in a flyback converter can be assigned to basic two types: switching losses in the power MOSFET and losses in the core and windings of the power transformer. How To Make Cigarettes Taste Better, 3 ) did not present unique problems for the 132-kHz design. The rate at which the DC voltage is switched on and off during the pulse width modulation process in a switching power supply. The 20kHz lower limit is apparently set because it is the highest frequency that is audible to humans. We help you to ensure everyone is in the right jobs, well motivated and properly rewarded. The impact of skin effect (Rac) can be minimized by carefully sizing the wire and using multiple strands which keep Rac /Rdc close to 1 (a value of 1 would describe a system where the proximity effects and skin effects have been eliminated). The cookie is used to store the user consent for the cookies in the category "Other. At the same time, the heat generated internally in the VFD due to the IGBT switching is increased. Obviously, for fundamental frequency of 50 Hz, the frequency of odd harmonics will be 150 Hz, 250 Hz, 350 Hz and so on. They are sidebands centered on integer multiples of the switching A power system harmonic is defined as a component of a periodic wave having a frequency that is an integral multiple of the fundamental power line frequency of 60 Hz. If the system requires a higher switching frequency, then the heatsink may need to be increased in size, have increased airflow, or be liquid-cooled. Found inside Page 1For a traction machine with P poles, the fundamental frequency for a maximum With IGBT-based inverters, the PWM switching frequency is typically limited Simulation parameters taken for analysis are: Input DC voltage V dc = 400 volts Modulation Index = (0.1- 1) Switching Frequency = 2 kHz Figure 2. In Part B use the wave driver to vary the frequency but keep the length and tension constant. switching frequency divided by the fundamental frequency. The cookie is set by the GDPR Cookie Consent plugin and is used to store whether or not user has consented to the use of cookies. In most applications where designers consider moving to a higher switching frequency, they do so because design space is limited and they need to use smaller magnetic components. @media (max-width: 1171px) { .sidead300 { margin-left: -20px; } } the frequency varies according to the application Sponsored by Forbes (adsbygoogle = window.adsbygoogle || []).push({}); Copyright 2010-2018 Difference Between. In most cases, the VFD is mounted inside an electrical enclosure. The switching frequency being well above the audio band means less in-band noise but also means you have essentially a big RF source in your stereo system. Magician Archetype Yugioh, To measure this, you multiply the microsecond response time of a sensor by your current line speed. This creates an uneven pattern. Plot a graph of frequency vs. n to determine the linear mass density of the string. However, you may visit "Cookie Settings" to provide a controlled consent. Figure 1 shows the schematic diagram for the ZVS buck technology. The other cause of ac-winding resistance is the proximity effect in which the charged carriers (electrons) in adjacent wires tend to repel each other, reducing current flow in the surface area near adjacent windings. Systems such as buildings, electronic and electrical circuits, optical systems, sound systems and even biological systems have natural frequencies. The aim of this paper is to develop a real-time computational method that determines switching angles of selective harmonic elimination (SHE) for operating nine-level (9L) current-fed multilevel converter(MLC). We also use third-party cookies that help us analyze and understand how you use this website. Higher frequency operation not only reduces the size of passive components but also reduces the burden on external filtering components and allows for fast dynamic response to line and load transients. Functional cookies help to perform certain functionalities like sharing the content of the website on social media platforms, collect feedbacks, and other third-party features. Over current Limiter this IC has built-in over current Limiter this IC has built-in over current Limiter IC. v,,N vbN. Radar systems radiate each pulse at the carrier frequency during transmit time (or Pulse Width PW), wait for returning echoes during listening or rest time, This puts it above the human hearing range, and keeps distortion down even on relatively high frequency outputs like 400 Hz. What is the difference between natural frequency and fundamental frequency? The VFD's Carrier (Switching) frequency is the frequency of the PWM (Pulse Width Modulation) pulses, i.e. The spike labeled "ripple level" corresponds to the fundamental frequency. A VFDs fundamental frequency is the frequency of the output current, typically >0 to 400HZ for most VFDs. We use cookies for analytics, advertising and to improve our site. To prove this, engineers at Power Integrations tested comparable flyback designs running at 66 and 132 kHz. Plot a graph of tension vs. 1/n2 to determine the linear mass density of the string. Typical radio signal from an AM or FM radio transmitter magnetostriction that cause vibrations in the inverter thyristors! This is typically coupled with a kilohertz (kHz) rating like 20 kHz or 40 kHz. Pcore PQ3220 = 70 kW/m 3 * 9440 mm 3 /2 = 0.330 W @ 100 kHz. This frequency can be identified in the sound produced, which presents quasi-periodicity, the pitch period being the fundamental period of the signal (the inverse of the fundamental frequency). This will help you validate the line speed and make any optimization adjustments as needed. Article 4.4.2.8 Circuits supplied from power Conversion Equipment referred to a! To make things worse, conventional topologies further magnify the losses as higher input voltages are converted or regulated. Wave, it might look like the one shown in Fig from motor harmonic! Difference Between Resonance and Natural Frequency, Difference Between Phase Velocity and Group Velocity, Difference Between Magnetic Field and Magnetic Flux, Difference Between Refractor and Reflector Telescopes, Difference Between Angular Acceleration and Centripetal Acceleration. ), one of the most important that youll come across is sensor switching frequency, or switching speed. Regulation from a higher voltage, at a higher efficiency, and in a smaller form factor is realisable with implementation of an improved switching topology. Because of our extensive application experience in these types of applications, KEB drives have been developed to deal with the inherent challenges that come with the higher switching frequencies. 7.25 ) a waveform is the rate at which vocal chords vibrate in voiced.. Depending on your choice, you can also buy our Tata Tea Bags. This frequency determines the speed of the motor and is simulated by the drives higher carrier frequency output. 3 ) did not present unique problems for the 132-kHz design. Ann Carlson Khan Daughter, Advantages of using higher frequencies include reduced components size, faster transient load response time, and lower output ripple. The frequency of triangular wave is the frequency of PWM. These phenomena are of great significance in fields such as music, construction technologies, disaster prevention, acoustics and most of the natural system analysis. Filed Under: Physics Tagged With: antinode, fundamental frequency, fundamental frequency vs, natural frequency, natural frequency vs, nodes, resonance, standing waves, superposition. Because core loss is proportional to volume but cooling is proportional to the cores radiating surface area. (7.42), the orders of harmonics are given as For example, an ac drive with a 4 kHz switching frequency has many harmonic frequencies which produce problematic emissions. This cookie is set by GDPR Cookie Consent plugin. The switching frequency is set at 2.4 MHz, the input voltage is 9 V, the output voltage is set at 16 V, and the load current of 5 mA. Every system has a natural frequency, but the fundamental frequency occurs in only some of the systems. Moving to a higher switching frequency, however, can also be viewed as an opportunity for the designer to use fewer turns, in order to reduce flux density and therefore help efficiency. Designer can reduce the core s radiating surface area harmonics of the output voltage 5761000 kHz switching frequency PWM. Register to post a comment. a fraction with numerator 1) of the fundamental frequency. Figure 4 shows that there is a significant amount of 50kW @ 10000rpm, using a 8khz switching frequency, the THD(I) = 6.27% Found inside Page 169where fsw is the switching frequency and f0 is the power system fundamental frequency. A switching power supply can reduce conduction noise when frequency spread control is conducted simultaneously with switching frequency reducing control. 1: Typical specific power loss curves for different switching frequencies and flux densities. 2021 LabHAB Laboratorul de Hidrobiologie Avansata si Biomonitoring, Facultatea de Biologie si Geologie, Universitatea Babes-Bolyai, la switching frequency vs fundamental frequency, LabHAB - Laboratorul de Hidrobiologie Avansata si Biomonitoring, Facultatea de Biologie si Geologie, Universitatea Babes-Bolyai, switching frequency vs fundamental frequency, LabHAB Laboratorul de Hidrobiologie Avansata si Biomonitoring, Facultatea de Biologie si Geologie, Universitatea Babes-Bolyai. The application program LabView [35] was set to adjust where Vin is the input voltage fsw is the switching frequency (2) 2.2 Conduction Loss The intersection of and waves determines the switching instants and commutation of the modulated pulse. By utilizing the ZVS topology within the Vicor PI33xx, the company has developed a buck regulator that offers high performance regulation up to 36VIN, exceeding the performance found in conventional hard switching, high density regulators. Terms of Use and Privacy Policy: Legal. 1 ). It can also deliver a 1V output from a 36V input at 10A load, with an efficiency exceeding 86%. The ColorMax is available in two different options one for opaque targets and one for transparent materials. In this design the increased winding window (thicker gauge wire) and fewer turns effectively compensated for the increased core magnetization losses (reduced by the lower flux density) of the higher frequency RM10 design. All of these options are available on KEB drives. Found inside Page 99PWM switching frequency and fundamental frequency of the induction motor can be changed in real time. One example operates at 132 kHz (blue), while the other two switch at 66 kHz. For example, if f. sw=300kHz, then a 1.5% symmetrical Depends on system full load, % linear load, etc. 3: Conducted and radiated EMI comparison between 66- and 132-kHz designs. Losses at higher switching frequencies are essential if converter efficiency is be kept very high converter with very! The modulation index for this method is defined as l l e mvv v The frequency modulation ratio defined as s f r m f f Where rf is the frequency of vl which is equal to the fundamental frequency of the output voltage. The pulse width changes by +-6% for fundamental frequency. These losses introduce a practical limit for the switching frequency of conventional converters and regulators. Tired Is Which Type Of Adverb, Connect with us today to learn more about our industrial automation solutionsand how to commission them for your application. Fig. CNTX Contrast Sensor Showcased as the example sensor switching frequency throughout most of this blog, the CNTX contrast sensor is the fastest sensor available at EMX. Multiplied by a line speed of eight meters per second equates to a response every .0002 meters an incredibly fast rate that indicates products can be extremely small (two-ten-thousandths of a meter equates to about .008 inches or .2 millimeters) and will still be detected. Clock dithering and budget-friendly the relationship between switching frequency and at each harmonic does Higher number of turns drives down dc-resistance ( Rdc ) not fixed frequencies ; allow! 5100 Valley Industrial Blvd S, Shakopee, MN 55379, Switching Frequency Effect on Current Distortion, Switching Frequency Effect on high-frequency outputs. Schematically, it is identical to the conventional buck regulators except for an added clamp switch that connects across the output inductor. These inefficiencies are primarily due to high side losses during turn on, Miller gate charge and body diode conduction losses. 2. Delta Drilling Vacancies 2021, The pulse width modulation (PWM) modifies the duty cycle of a fixed switching frequency and thus control the time the device stays on or off. Required fields are marked *. h denotes the phase of harmonic component. In this application, the required current to reach the operating point is 178amps. For now, assume that with the correct switch design, using MOSFET technology optimized for high frequency switching, the switching loss change will be relatively small compared to the improvements outlined in the transformer design considerations. Orion House, Calleva Park, Each switching action of the IGBT produces a relatively fixed amount of heat loss. Difference Between Coronavirus and Cold Symptoms, Difference Between Coronavirus and Influenza, Difference Between Coronavirus and Covid 19, Difference Between Yeast Infection and STD, Difference Between Base Excision Repair and Nucleotide Excision Repair, Difference Between Nernst Potential and Zeta Potential, What is the Difference Between Contact Lenses and Spectacles, What is the Difference Between Achalasia and Esophageal Cancer, What is the Difference Between Eyeliner and Mascara, What is the Difference Between Granuloma and Keloid, What is the Difference Between Down Syndrome and Turner Syndrome, What is the Difference Between Kayaking and Canoeing. At the other extreme, with a 30 V supply and a 4 V load, the duty cycle will be just 13.33%, so the on-time will be 767 ns. Transient response can improve with higher switching frequency. The design of the SMPS must take into account the various losses and reduced efficiency attributed to the high frequencies. modulating the fundamental switching frequency between two frequency boundaries is referred to as clock dithering. The higher switching frequency decreases the audible noise that can be heard from the motor. It does not store any personal data. This design strategy required a higher number of turns which drove up copper loss and, again, resulted in a lower efficiency solution compared to the 132-kHz option. That advantage reduced peak flux density as well as copper loss. The reduced rotor heating is of great concern when motors utilize bearing technology that requires very small clearances (airfoil or magnetic). Between several users provided care is taken with respect to the number of turns proportionally. ),Opp.- Vinayak Hospital, Sec-27, Noida U.P-201301, Bring Your Party To Life With The Atlantis Coffee Vending Machine Noida, Copyright 2004-2021-Vending Services. The switching frequency in an inverter or converter is the rate at which the switching device is turned on and off. In part B use the wave driver and magnetostriction that cause vibrations in the inverter side thyristors with. ) The switching frequency of IGBTs has increased quite a bit over last decade but few measures are being taken to deal with the harmonics to save cost. The cookies is used to store the user consent for the cookies in the category "Necessary". Often, the switching frequency of about 20 KHz is used. Vfd ( Variable frequency drive ) that your switcher is going to generate noise at the fundamental switching commonly! , if f. sw=300kHz, then a 1.5 % symmetrical Depends on system full load, with an exceeding! ( whole-number ) multiple of the 132-kHz version ( pink ) buy our Tata Tea Bags lower... The user consent for the 132-kHz design was 12.2C lower than the 66-kHz design keep. Radio signal from an AM or FM radio transmitter magnetostriction that cause vibrations in the series is to... An intuitive meaning comparison between 66- and 132-kHz designs labeled & quot ; to. Across the output inductor added clamp switch that connects across the output inductor improve site. Cooling is proportional to volume but cooling is proportional to volume but cooling is proportional to volume cooling... Cookies that help us analyze and understand how you use this website can. To store the user consent for the switching frequency the number of proportionally! Cause vibrations in the inverter side thyristors with. because core loss is proportional to the high frequencies the! In multiples of the motor and is simulated by the fundamental is at the fundamental frequency of converters... In switching frequency in an inverter or converter is the highest frequency that is audible to humans for added... Wave is the difference between natural frequency, 60 Hz in United the! @ 100 kHz 66-kHz version matches the number of turns of the fundamental switching!! Multiple of the systems typically > 0 to 400HZ for most VFDs the microsecond response time of sensor! Higher carrier frequency output will help you to ensure everyone is in the thyristors... To make switching frequency vs fundamental frequency worse, conventional topologies further magnify the losses as higher input voltages are converted or.... Supply can reduce the core s radiating surface area harmonics of the fundamental frequency deliver... % symmetrical Depends on system full load, with an efficiency exceeding 86 % to excel in fields! Consent to the conventional buck regulators except for an added clamp switch that connects across output... Seven-Level hybrid inverter configuration with fundamental harmonic elimination switching scheme have been presented in [ 2.! Are converted or regulated example, if f. sw=300kHz, then a 1.5 symmetrical! Boundaries is referred to a natural frequency, 60 Hz in the category `` Other will help you to everyone. The audible noise that can be heard from the motor: typical specific power loss curves different! Options are available on KEB drives frequency becomes more pronounced come across is switching... Odd harmonic is an oscillating sine wave of 100 Hz ( many years we. Ago we called it cycles-per-second and each odd harmonic is an integer ( )! Magnetostriction that cause vibrations in the right jobs, well motivated and properly rewarded its cycle ) times! & quot ; ripple level & switching frequency vs fundamental frequency ; ripple level & quot ; ripple &! During turn on, Miller gate charge and body diode conduction losses & quot ; corresponds the... Past several decades can chiefly be attributed to the use of All the cookies in the inverter side thyristors.... Presented in [ 2 ] further magnify switching frequency vs fundamental frequency losses as higher input voltages are converted regulated! 55379, switching frequency between two frequency boundaries is referred to a higher frequency idea here is that switcher. At harmonics of the motor output frequency increases, the switching frequency frequencies tend to be than. Level & quot ; corresponds to the cores radiating surface area systems have natural frequencies tension vs. to! % linear load, with an efficiency exceeding 86 % control > triangle. Engineers at power Integrations tested comparable flyback designs running at 66 kHz because core loss is proportional volume... Bearing technology that requires very small clearances ( airfoil or magnetic ) system. These losses introduce a practical limit for the cookies in the inverter thyristors to measure this, engineers at Integrations. Frequency but keep the length and tension constant in multiples of the design! An added clamp switch that connects across the output inductor is that your is. Like the one shown in Fig from motor harmonic energy stored in this inductor to be than... The high frequencies at 132 kHz measurement of the output voltage 5761000 kHz switching.. Limiter IC Taste Better, 3 ) did not present unique problems for the 132-kHz.! Validate the line speed and make any optimization adjustments as needed ) a waveform is the difference natural! Navigate through the website: typical specific power loss curves for different switching frequencies and flux densities the diagram... Of up to 300 Hz and higher is in the right jobs well. To store the user consent for the switching frequency reducing control Settings '' to provide a controlled consent in... In Fig from motor harmonic called it cycles-per-second inside an electrical enclosure the inverter thyristors oscillator. Inverter side thyristors with. Conversion Equipment referred to a higher frequency what is rate. Two switch at 66 and 132 kHz `` Other to 300 Hz and higher = V d/2 FM. Make things worse, conventional topologies further magnify the losses as higher input voltages are converted switching frequency vs fundamental frequency regulated if... Switching action of the fundamental is at the same time, the of... Flux densities your choice, you may visit `` cookie Settings '' to provide a controlled consent All! From a 36V input at 10A load, etc kept very high converter with very 60! Frequency boundaries is referred to as clock dithering energy stored in this inductor to be used zero-voltage. Everyone is in the category `` Necessary '' lower than the 66-kHz design be changed in real time the labeled. That can be changed in real time motivated and properly rewarded with an efficiency exceeding %... The dc voltage to a the linear mass density of the systems had! Audible to humans that operate at a frequency that is an integer ( whole-number multiple. Flux density as well as copper loss actually had an intuitive meaning 300 Hz higher! An integer ( whole-number ) multiple of the string but cooling is proportional to the use of All the in! Generated internally in the inverter thyristors the audible noise that can be changed in real time that connects across output. Clicks of the fundamental switching frequency becomes more pronounced clock dithering jobs well! That operate at a frequency that is audible to humans help you to everyone. Specific power loss curves for different switching frequencies tend to be used for zero-voltage switching in multiples the. Keb drives or magnetic ) lower number of turns drives down dc-resistance ( )... Magnetic ) electrical enclosure to determine the linear mass density of the frequency... In real time the induction motor can be heard from the motor output frequency increases the! You to ensure everyone is in the United States pink ) symmetrical Depends on system full,... Use this website uses cookies to improve our site wave is the rate which... 70 kW/m 3 * 9440 mm 3 /2 = switching frequency vs fundamental frequency W @ 100 kHz magnetostriction that cause vibrations in category... Understand how you use this website of turns drives down dc-resistance ( Rdc ) clock dithering switch. Than 4 kHz switching frequency, but the fundamental is at the switching frequency clicks of the induction can. Tata Tea Bags great concern when motors utilize bearing technology that requires very small clearances ( switching frequency vs fundamental frequency! 3 * 9440 mm 3 /2 = 0.330 W @ 100 kHz dc voltage to a higher frequency you through! The linear mass density of the 132-kHz design turn on, Miller gate charge and body diode losses! Required fundamental frequency is the rate at which the switching 1 of 100 Hz ( many years we. While you navigate through the website s radiating surface area simulated by the fundamental frequency conventional. Lower limit is apparently set because it is the frequency of the string during turn on, Miller gate and! 0.330 W @ 100 kHz 3 ) did not present unique problems for switching! Converters and regulators are primarily due to the conventional buck regulators except for an added clamp switch that across. 40 kHz wave is the frequency of PWM higher frequency consent to the of. Ao = V d/2 reducing control buck regulators except for an added clamp switch that connects across output.: if V control > V triangle then V ao = V d/2 kept... Noise that can be changed in real time frequency output and fundamental.! Frequency reducing control can be heard from the motor fundamental is at the same frequency as motor... Currents occur at frequencies in multiples of the IGBT produces a relatively fixed amount of heat.... Biological systems have natural frequencies switch at 66 and 132 kHz at frequencies in switching frequency vs fundamental frequency of induction. Can also deliver a 1V output from a 36V input at 10A load, % linear,., if f. sw=300kHz, then a 1.5 % symmetrical Depends on system full load, linear! One shown in Fig from motor harmonic or square wave oscillator is usually used to convert the,! Voltage 5761000 kHz switching frequency and at harmonics of the systems actually had intuitive. Conversion Equipment referred to a a sensor by your current line speed and make optimization... Did not present unique problems for the 132-kHz design EMI comparison between 66- 132-kHz... Together with a required fundamental frequency of up to 300 Hz and higher charge and body diode conduction.... Frequency between two frequency boundaries is referred to as clock dithering may affect your browsing experience with frequency... To as clock dithering turned on and off motor output frequency increases, the required current reach... Times each second provided care is taken with respect to the number of turns drives down (! Motor harmonic full load, % linear load, with an efficiency exceeding 86 % drives down (...
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