At CtrlTech, we deliver quality Frequency Converter and experience of implementation
A frequency converter, sometimes known as a power frequency changer, is a device that converts output power from 50 Hz to 60 Hz or 50 Hz to 400 Hz. Power frequency converters come in a variety of configurations, including rotary converters and solid state converters.
Electrical energy is used to power a rotary type system. Solid-state frequency converters convert the input alternating current (AC) to direct current (DC).
You will encounter the requirement to modify current frequency in industrial applications. Frequency converters, as the name implies, are Hertz converters. The frequency converter converts fixed-frequency, fixed-voltage sine-wave power (line power) to variable-frequency, variable-voltage output. The variable-voltage output is used to control the speed of an induction motor. The most often used unit of all configurations is the frequency converter 50Hz to 60Hz.
There are two primary sorts of frequency converters that you might utilise. They include both static and rotational frequency converters. Let us take a closer look at these distinctions.
Static frequency converters are power converters that convert incoming alternating current (AC) to direct current (DC) and then to the appropriate alternating current frequency and voltage (rectifier stage). Static frequency converters excel where low noise, compactness, accuracy, or flexibility are required. Due to their inherent silence, these machines are ideal for usage in offices and laboratories. Typically, noise levels are less than or equal to 65 decibels (dB). The most typical phase conversions are single-phase to three-phase and three-phase to single-phase.
Static frequency converters are ineffective in starting motor loads due to the constant motor starting surge current required to start motors. Motor loads require a strong kick to start (6 to 10 times full load amps). This motor starting spike, also referred to as "locked rotor" current, is extremely brief, lasting only a few milliseconds at its peak before reverting to normal operating current in about a second. On the other hand, a static frequency converter does not "understand" that this large surge will last only milliseconds and so shuts down to protect itself. The converter's overload capacity must be matched to the motor's starting current. As a result, the converter is significantly oversized.
Airports require a frequency converter that converts frequencies from 50 to 400 Hz as a ground power unit (GOU). The advantage is that the same machine may be configured to operate as a 60Hz to 50Hz or 50Hz to 60Hz converter. Static converters are also affected by temperature and humidity. They are essentially air-conditioned and are unable to withstand adverse conditions such as salt fog. They normally provide ten years of trouble-free service.
Incoming alternating current is transformed to rotational mechanical power and transmitted to a generator, which converts the mechanical power to electric alternating current output power. Electrical power is expressed in Kilowatts (kW) or Kilovolt-Amperes (KVA), whereas rotational power is expressed in Horsepower (HP). This technique necessitates the conversion of frequency, voltage, and/or phase. In motor-generator systems, the driving motor and generator are coupled in a variety of ways. Rotary frequency converters are always the optimal solution for motor loads.
Belt coupled converters are the simplest and cheapest method because they use drive belts and pulleys to convey energy from the motor to the generator and adjust the frequency by adjusting the pulley ratio. While some clients express concern about drive belt longevity, drive belts do not fail in practise when designed and installed properly. 50 to 60Hz converter
A 50 to 60 Hz frequency converter is ideal for industrial applications. These frequency converters are capable of converting the frequency to a stable range of 50Hz to 60Hz. This will assist you in obtaining the necessary amount of power to carry out your industrial applications without encountering any difficulties.
You'll see that the output power of the 400 Hz frequency converters is boosted up to 400 Hz, or 500 cycles per second. These frequency converters are extremely common in the navy and aerospace industries. For instance, you'll see how they're integrated into the latest helicopters on the market.
In the United States and many other nations, 60 Hertz (Hz) is the frequency of wall current. 60 Hertz (Hz) indicates that a generator's rotor rotates 60 times per second and that the voltage changes from positive to negative and back to positive 60 times per second - one complete cycle. Frequency adjustments are used to safely and reliably supply alternating current (AC) at 50 or 60 Hz from a 50 or 60 Hz input power source.
Along with energy savings and improved process control, frequency converters can bring the following additional benefits:
The frequency converter converts a basic sinewave (line power) fixed-frequency voltage to a variable frequency variable-voltage output used for the induction motor controls.
The primary function of an aquatic frequency converter is to save energy. Energy savings can be substantial if the pump speed is controlled instead of the flow through the application of throttling valves.
For instance, a 20% decrease in speed can save up to 50% on energy. This describes reduction in speed and the energy savings correspondingly. Apart from energy savings, the rotor, bearing and screen life has improved considerably.
Frequency converters offer an ideal method for matching pump and ventilator flow rates to system requirements in numerous different types. It converts standard power plant (220V or 380V, 50 Hz) into a regulated AC motor voltage and frequency. The AC motor frequency determines the engine speed.
The AC engines are usually identical standard motors which can be connected through the AC power line. The operation can be maintained by incorporating bypass starters even if the inverter fails.
Also offering additional benefits: higher bearing life and pump seal life. The pump is not subject to higher pressures than necessary by maintaining only the pressure required to comply with the system requirements. The components therefore last longer. Even fans operated by frequency converters have the same benefits - but to a lesser degree!
Many specifiers obtain detailed information from manufacturers to achieve optimum efficiency and reliability. This can include the efficiency of frequency converters, the required maintenance, frequency converter diagnostics capabilities, and general operational features.
They then analyse in detail which system will yield the best return on investment.
Frequency converters can offer other benefits as well as energy savings and improved process control:
Without the use of a separate controller, a frequency converter may be used to control the process temperature, pressure or flow. The interface between driven equipment and frequency converter uses suitable sensors and electronics.
Maintenance costs can be reduced, as lower running speeds give rooms and motors a longer life.The removal of throttling valves and damping valves also eliminates the maintenance of these devices.
There is no need to have a soft engine boot.
In a liquid system, controlled acceleration can solve the problem of hammers of water.
Ability to limit torque to a user-selected level of the frequency converter can protect driving devices that do not tolerate excessive torque.
When two adjacent power grids operate at different utility frequencies, frequency changers are used to convert bulk alternating current power from one frequency to another.
A variable-frequency drive (VFD) is a type of frequency converter that is used to control the speed of alternating current motors such as those used in pumps and fans. Because the speed of an ac motor is proportional to the frequency of the ac power supply, changing the frequency allows for changing the motor speed. This enables the output of the fan or pump to be varied in response to process conditions, potentially resulting in energy savings.
Additionally, a cycloconverter is a type of frequency changer. Unlike a variable frequency drive (VFD), which employs an AC-DC stage followed by a DC-AC stage, a cycloconverter employs no intermediate stages.
Additionally, the aerospace and airline industries benefit from this technology. Often, aeroplanes operate at 400 Hz, necessitating the use of a 50 Hz or 60 Hz to 400 Hz frequency converter in the ground power unit that powers the aeroplane while it is on the ground. Airlines may also use the converters to provide passengers with in-flight wall current for use with laptops and other electronic devices. On Navy warships, radio and combat systems equipment is frequently also powered at 400 Hz to reduce noise on the rectified DC signal.
Frequency converters are a critical component of modern multi-megawatt class wind turbines that use doubly fed induction generators (DFIGs).
A high-voltage direct current system can act as a frequency converter for large loads.
Frequency converters are divided into three distinct sections:
Rectifier Circuit – Diodes, SCRs, or insulated gate bipolar transistors are used in this circuit. These devices convert alternating current from the power grid to direct current.
DC Bus – This bus is made up of capacitors that filter and store the direct current charge.
Inverter – a device comprised of high-voltage, high-power transistors that converts direct current to a variable-frequency, variable-voltage alternating current delivered to a load.
Additionally, frequency converters incorporate a powerful microprocessor that regulates the inverter circuit to deliver an almost pure variable-frequency sinusoidal voltage to the load. Additionally, the microprocessor controls the configuration of input/output devices, frequency converter settings, fault conditions, and communication protocols.
Nowadays, frequency converters are used almost everywhere to control the speed of single-phase and three-phase electric motors. And not just in industrial settings, but in daily life as well. Starting with extremely low power ratings for controlling washing machine drums and progressing to medium power ratings for municipal water supply pumps.
Variable frequency drives are used in the industrial landscape for a variety of purposes, including the following:
These functions are utilised in a wide variety of industrial sectors:
Frequency conversion is a broad term that encompasses a variety of processes that alter the frequency of physical phenomena:
A frequency changer is an electronic device that converts one frequency of alternating current (AC) to another frequency of alternating current (AC).
A variable-frequency drive is a special kind of frequency converter.
In nonlinear optics, the term "frequency conversion" refers to various manipulations of the frequency of light.
In signal electronics, a heterodyne is used to convert frequencies.
Rotary and solid state converters are the two primary forms of frequency converters, with solid state converters acting electrically and rotary converters operating electromechanically. These devices are graded according to their input and output power, as well as their frequency, and can be designed to handle very low current up to extremely high current. They are frequently used in conjunction with transformers to give variable output voltage and frequency. Typical frequency converters perform proper frequency conversion through the employment of a collection of semiconductors and diodes. These devices are frequently used in equipment that requires variable speed AC motors and in systems that demand a different frequency AC current than that supplied by the available source.
To convert ac current to a different frequency, a frequency converter performs a two-stage conversion. It converts ac to dc first, and then dc to desired frequency ac second.
Thus, the frequency converter operates in two modes: first, the rectifier circuit converts ac to dc, and then, the inverter circuit using thyristors/IGCTs/IGBTs converts dc to ac at the desired frequency. The converter stage is where the frequency is changed or shifted.
If voltage conversion is required, a transformer will typically be incorporated into either the ac input or output circuitry, and this transformer may also serve as galvanic isolation between the input and output ac circuits.
Additionally, a battery may be added to the dc circuitry to improve the converter's ride-through capability during brief interruptions in the input power.
The frequency converter can convert 60Hz to 50Hz and can also boost 110V to 220V via an internal step-up transformer, or vice versa. Prior to purchasing a frequency converter, it is prudent to ascertain the types of loads to which the converter will be connected. There are five common types of load: 1 is a resistive load; 2 is an inductive load; 3 is a capacitive load; 4 is a rectifier load; 5 is a regenerative load; and 6 is a mixed load. The frequency converter power capacity should be chosen in accordance with the load capacities and types.
The HZ-50 and HZ-60 series frequency converters are not load type specific; they can be used with resistive, inductive, capacitive, rectification, and mixed loads. The frequency converter's technical parameters are validated using standard rated resistive load conditions; the frequency converter can operate for an extended period of time under these conditions. However, in order to account for power grid voltage fluctuations, inrush current, and short-term overload factors, we should leave a sufficient margin in the frequency converter's power capacity selection. Manufacturers have made the following recommendations:
Power Capacity = 1.1 load power capacity when a resistive load is used.
RC load: Power Capacity equals 1.1 the apparent power capacity of the load.
Motor load: In the case of a hard start (direct start), the motor starting current will be approximately 5–7 times the rated current; the starting time is typically less than 2 seconds. Generally, the frequency converter's overload capacity is 200 percent within a few milliseconds before overload protection is triggered. Therefore, if the motor is hard starting, it is recommended to choose a frequency converter with a power capacity six times that of the motor. This means that the converter's rated current should be greater than the load's starting current. Otherwise, you'd be wise to equip the motor with a soft starter or variable frequency drive.
Rectifier load: if the input circuit does not include a soft start device, the load can be treated as a short circuit during the input switch closing moment, generating a large impact current that triggers the frequency converter overcurrent protection. If there is a high starting inrush current on a frequent basis, it will also affect the load circuit. As a result, the rectifier load input circuit should implement soft start measures to limit startup current.
Due to the fact that the rectifier load's current is pulse current, the current crest factor is up to 3 - 3.5 times, which has an effect on the output voltage waveform in the long run, depending on the load's current crest factor. Generally, when the current crest factor exceeds 2:00, the following formula is used to determine the frequency converter power capacity: Power capacity equals the crest factor of the load current divided by the apparent power of the load.
Regenerative loads, such as reversible motors or variable speed motors, generate a high back EMF that can easily damage the frequency converter. Please specify such loads when ordering the frequency converter.
Mixed load: when selecting a frequency converter, take into account the proportion of each load's power capacity.
Voltage and frequency of the frequency converter The factory default input voltage is 220V single phase, 380V three phase, 50Hz or 60Hz. If you require a different frequency converter input voltage or have other special requirements, please specify them during the ordering process.
Static frequency converters do not contain rotational components and are also referred to as solid state converters. This is in contrast to rotary frequency converters, which utilise an electric motor to generate adjustable frequency output.
Static frequency converters convert fixed grid power from AC to DC to AC via internal electronic components and components; the multifunctional inverter converts the mains (50 or 60 Hertz, 120V, 240V, 400V) via a conversion circuit to the required voltage and frequency power source; the output power source can simulate international power system standards. Enter single or three phase ac power, convert via ac to dc and dc to ac, and the output is a stable pure sine wave. Additionally, the output can reach 400 Hertz for use in the aircraft industry.
To keep up with the trend of the times, the static frequency converter uses advanced PWM (Pulse Width Modulation) technology and an advanced IGBT power module as the drive, which has a small volume, high reliability, and low noise characteristic. A static frequency converter employing digital signal processing technology can offer precise data on voltage, frequency, current, and power factor; The big capacity IGBT module design and specific driving circuit for IGBT can significantly minimise the complexity of the circuit and improve the static frequency converter's reliability and stability; electrically isolated input and output, anti-jamming, and engine security. The converter can supply single phase voltages of up to 300 volts, three phase voltages of up to 520 volts, and a frequency of up to 40 499.9 Hz, with configurable frequency according to the set.
Solid State units are power converters that convert incoming alternating current to direct current (rectifier stage) and then convert the direct current to the needed alternating current frequency and voltage. Solid state frequency converters are appropriate for applications where low noise, small size, precision, and adaptability are required. Due to the inherent quiet nature of static frequency converters, they are well suited for use in office and laboratory situations. Noise levels are typically less than or equal to 65 decibels (dB). Single phase to three phase and three phase to single phase phase conversions are very popular.
In worldwide power networks, 50 Hz and 60 Hz power sources are most frequently employed. Certain countries (regions) have a 50Hz power system, whereas others have a 60Hz power grid.
Generally used in nations with a 50Hz power supply to power equipment, machines, and appliances imported from countries with a 60Hz power supply, such as the United States of America.