2Frequency Converter
The frequency converter is a machine which can convert the voltage and frequency of a AC power source to a new AC power at a required voltage and frequency with electrical or galvanic isolation between the two AC power.
Basically, there are 2 types of frequency converters available which are the rotary frequency converter and the static frequency converter. Both having different characteristic to suit different types of applications.
Rotary Frequency Converter The rotary frequency converter used a motor which is driven by AC source frequency and voltage to drive a AC generator or alternator to produce the required frequency and voltage. The coupling between motor and generator is either belts with pulleys system or direct shaft coupling. Hence, it is called rotary frequency converter. In the earlier days, it is also MG set which stands for motor and generator.
Key features are:
A. the input and output of the converter is totally isolation via the mechanical coupling which is ideal for frequency converting application.
B. the generator produce pure sine wave AC power which is not sensitive to surge current and lightning
C. able to support high capacity or high voltage application
D. the rugged with moisture and heat resistant construction make it suit for outdoor application
E. the output can be synchronized for parallel and load sharing application which is ideal for energy saving, high capacity and maintenance redundancy
F. the converter does need air-conditioned room to function normally and hence can save cost and environment
Example Frequency Converter Shore Supply or Cold Iron 415V 50Hz to 440V 60Hz The frequency converter in shipyard or berth are sometimes called shore supply or cold iron. When a ship berths or docks in the shipyard for repair and maintenance, the generator on board the ship will be shutdown for maintenance too. It is necessary to provide AC power to the ship for all equipment on board such as lighting, chiller, pump, hoist, etc...to function normally. Usually, the ship AC power is 440V 3phase 60Hz. Country like Singapore, the utility power is 415V 3phase 50Hz. Therefore, a frequency converter is required to convert from 415V 50Hz to 440V 60Hz for the ship use. Depending on the numbers and size of the ships, the capacity of frequency converter can be as high as 5,000kVA. In this case, may be a group of 10 units of 500kVA frequency converters are installed to operate into auto parallel and load sharing to support 5000kVA power usage depending the numbers of ships at berth and loading needs. Using the power from utility, we can also save our Earth by reducing consumption of our scare fuel resource and the harmful carbon emission.
Typical applications
Shipyards, coast guards, navy, yacht
3Phase 200V, 380V, 400V, or 415V 50Hz to 440V, 460V, 480V or 600V 60Hz
Manufacturing machinery and factory
3Phase 200V, 380V, 400V, or 415V 50Hz to 208V, 220V, 460V, 480V or 600V 60Hz
3Phase 208V, 220V, 460V, 480V, 600V 60Hz to 200V 380V, 400V, 415V 50Hz
3Phase 200V, 380V, 400V, or 415V 50Hz to 208V, 220V, 460V, 480V 100Hz, 200Hz
3Phase 208V, 220V, 460V, 480V or 600V 60Hz to 200V 380V, 400V, 415V 100Hz, 200Hz
Airport, hangers, avionic labs
3Phase 200V, 380V, 400V 415V 50Hz to 200V 400Hz
3Phase 208V, 220V, 440V, 480V 60Hz to 200V 400Hz
Static Frequency Converter
The static frequency converter used semiconductors to rectify AC source power at
source frequency and voltage into DC power before using an inverter to generate a new
AC power at the required frequency and voltage from the DC power. There is no moving
parts except for some cooling fans in the converter.
Key features are:
a. the input and output are isolated via isolation transformer
b. the output voltage regulation can be stable up to 0.2%
c. the output frequency can be very stable up to 0.01Hz
d. the output voltage and frequency can be variable to suit testing purposes
e. suitable for indoor application with air-conditioned ambience
f. compact in size which save space for installation
Example Aircraft Hanger 415V 50Hz to 200V 400Hz When an aircraft comes into hanger for maintenance or repair, the engine and generator on board are switch off. Because aircraft needs to minimize its weight, it uses 400Hz AC power equipments. Our utility power is 415V 50Hz, a static frequency converter is installed in the hanger facility to supply 200V 400Hz power to the aircraft during the repair works. The power consumption by aircraft is small, one or two units of frequency converter is sufficient to supply the required power to all the aircraft in one hanger.
Typical applications
Manufacturing machinery and factory
1Phase 100V, 200V, 220V, 230V, 240V 50Hz to 0~300V, 40~499.9Hz
1Phase 100V, 110V, 115V, 120V, 127V 60Hz to 0~300V, 40~499.9Hz
3Phase 200V, 380V, 400V, or 415V 50Hz to 208V, 220V, 460V or 480V 60Hz
3Phase 208V, 220V, 460V, 480V 60Hz to 200V 380V, 400V, 415V 50Hz
3Phase 200V, 380V, 400V, 415V 50Hz to 208V, 220V, 460V, 480V 100Hz, 200Hz
3Phase 208V, 220V, 460V, 480V 60Hz to 200V 380V, 400V, 415V 100Hz, 200Hz
Airport, hangers, avionic labs
3Phase 200V, 380V, 400V 415V 50Hz to 200V 400Hz
3Phase 208V, 220V, 440V, 480V 60Hz to 200V 400Hz
Rotary Frequency Converter
| Capacity | 50, 100, 150, 200, 250, 300, 500, 600, 800, 1000, 1250, 1500, 2000, 5000, 6000, 7000, 8000, 10000kVA |
| Number of Phase | 1 phase or 3 phase |
| Input Voltage | 200, 208, 220, 380, 400, 415, 440, 460, 480, 600V 3W or 3W+N |
| Input Frequency | either 50Hz or 60 Hz |
| Output Voltage | 200, 208, 220, 380, 400, 415, 440, 460, 480, 600V 3W+N |
| Output Frequency | either 50±0.5Hz or 60±0.6Hz or 400±2Hz |
| Waveform | Pure Sine Wave |
| Response Time | 20ms |
| Coupling | Belts and Pulleys System or Common Shaft or Direct Coupler DNC™ |
| Soft Start | Soft Starter Control Circuitry TMS™ or Soft Starting Technology EFI™ |
| Technology | Patented Electromagnetic Drive System EDMS™ |
| Efficiency | 92% |
| Parallel Function | Automatic Power Synchronizer APS™ |
| Instruments | Status Lamp, Voltmeter, Ammeter, Frequency Meter, Thermometer |
| Protections | Fuses, Over Current, Under Voltage,Under Frequency, Over Frequency, Over Temperature |
| Noise Level | Standard 88dBA, low noise 75dBA or soundproof 65dBA |
| Enclosure | All components housed in rugged steel and aluminum enclosure or modified 40 feet container with powder coated finishing for indoor application or marine paint finishing for outdoor climate |
Static Frequency Converter
| Capacity | 50, 100, 150, 200, 250, 300kVA |
| Number of Phase | 1 phase or 3 phase |
| Input Voltage | 200, 208, 220, 380, 400, 415, 440, 460, 480V 3W or 3W+N |
| Input Frequency | 50Hz or 60Hz or 47~63Hz |
| Output Voltage | 200, 208, 220, 380, 400, 415, 440, 460, 480V 3W+N |
| Output Frequency | 45~65, 50, 60, 100, 200, 400, 500, 40~500Hz with ±0.1, ±0.5, ±0.01Hz accuracy |
| Waveform | Pure Sine Wave |
| Response Time | 5ms |
| Technology | Solid state semiconductor system |
| Efficiency | 92% |
| Instruments | Status Lamp, Voltmeter, Ammeter, Frequency Meter |
| Protections | Fuses, Over Current, Under Voltage,Under Frequency, Over Frequency, Over Temperature |
| Noise Level | Standard 75dBA or Low Noise 65dBA |
| Enclosure | All components housed in rugged steel enclosure with powder coated finishing or paint finishing for indoor application |
