Inverters
Some of you may never have heard of inverters and have no idea what they are. But many others are familiar or have even worked with these appliances.
For the first group mentioned above, we will try to explain in detail what inverters are, particularly the frequency inverter device available in our online store.
If you are thinking of buying a frequency inverter or you just want to find out more and acquire new and interesting knowledge, you have come to the right place: Elmark.
What is a frequency inverter and what is it used for?
A frequency inverter is an appliance that changes fixed voltage and frequency into variable voltage and frequency or, in other words, converts direct current into alternating current.
For those more familiar with this field, frequency inverters do the opposite of rectifiers, which convert alternating current into direct current.
For the sake of clarity, we will briefly explain the difference between direct current and alternating current.
Direct current does not change in direction and value over time. Sources of this type of electricity include batteries, accumulators, solar cells, dynamos, etc.
Alternating current varies in value and direction at intervals. It is used for domestic and industrial purposes. In households it introduces single-phase current into the electrical system, while three-phase current is used in industry, but we will not go into further detail about this.
Frequency inverters are mainly used to smoothly regulate the speed of asynchronous motors, which are widely used in industry.
Although frequency inverters are mainly needed in industry, which partly explains their high cost, this is far from their only use.
Inverters with much smaller capacities are also available and suitable for domestic purposes. In Elmark's online store you will find a wide selection from which everyone can find something for themselves.
How is a frequency inverter designed and how many types are there?
Now that we have introduced you in general to the functionality and purpose of frequency inverters, we will go into a little more detail and tell you how they are designed.
Frequency inverters have several components including a transistor inverter, a rectifier and a DC filter.
Therectifier converts the AC power supply into pulsating direct current using special diode modules.
This is not how the transistor inverterworks. Its purpose is to transform direct current into so-called broad-pulse modulated (BPM) alternating current.
The third component, DC filters, consist of a variety of filter elements including capacitors and filter throttles.
All these components play a huge role in the functions of a frequency inverter. But we should also consider the "brain" that drives the entire appliance, i.e. the microprocessor controller which, in addition to acting as a control system, also provides a sinusoidal current.
Now that have taken a look at a frequency inverter from the inside, we will examine its different types.
Basically, frequency inverters can be vector-based or scalar, the difference being the way the electric motor is controlled. In other words, the type of frequency inverter is determined by means of a voltage calculation device.
Scalar inverters work as follows: voltage is a function of frequency and is calculated by linear interpolation between several reference points If you use a scalar frequency inverter you will be able to determine their value.
The operating process of vector invertersis slightly different. You must first set the electrical parameters of the electric motor you are operating. You can only determine the voltage value by modelling the transient processes in the motor itself. Using a vector frequency inverter therefore requires a higher level of knowledge, particularly in power drive theory.
Where the main problems arise for each type of frequency inverter
When using a frequency inverter, you should be aware in advance of several issues that may arise.
Possible problems include engine vibration and potential overheating of the asynchronous motor at low rotation speeds.
Peak power surges at the motor terminals are likely to occur. You should not underestimate this part of the operating process.
With regard to the frequency inverter, at some point there may be higher harmonics that usually occur at the output of the appliance.
Another problem you should be aware of is so-called electro-erosion of bearings which can lead to frequencies that exceed the synchronous frequency when using a frequency inverter.
Protective devices to help with frequency inverter problems
Now that we have outlined the potential problems, we can offer possible solutions in the form of protective equipment.
To begin with, we advise you to use an asynchronous motor with higher-grade insulation. This will ensure that you have fewer problems at a later stage.
To extend the life of the motor itself, a good approach is to install external filters (throttles) that will help limit the high-frequency components to standard values.
You can also take a number of steps to ensure the operation of the frequency inverter and minimise the risks of problems and incidents.
Provide independent cooling, especially for operation at low speed and shaft rotation. In addition, thermistor shields may be added to prevent the stator coil overheating.
To ensure smooth operation of the frequency inverter, it is advisable to use bearings that have:
- Ceramic parts;
- Insulated outer ring;
- Insulated inner ring;
- Dielectric coating.
To avoid power surges at the motor terminals, a shielded cable with a minimum length can be used.
Frequency inverter products in our online store
In the Inverter category of our online store you can acquire a frequency inverter that will not only do a great job for you, but will also be a benchmark for quality and long service life.
Here you will find all sorts of models both for large and small-scale industry and smaller businesses and even the household sector.
Although categorised by purpose, input voltage, maximum power and current, all our inverters are manufactured with high quality materials and are all covered by our quality guarantee.
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FREQUENCY INVERTER E2000- 0150 T3 15.0KW 32A 400V 423412P
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Input voltage 400V Maximum power 15.0kW Maximum current 32A Warranty -
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FREQUENCY INVERTER E2000- 0185 T3 18.5KW 38A 400V 423413P
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Input voltage 400V Maximum power 18.5kW Maximum current 38A Warranty -
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FREQUENCY INVERTER E2000- 0220 T3 22.0KW 44A 400V 423414P
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Input voltage 400V Maximum power 22.0kW Maximum current 44A Warranty -
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FREQUENCY INVERTER E2000- 0300 T3 30.0KW 60A 400V 423415P
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Input voltage 400V Maximum power 30.0kW Maximum current 60A Warranty -
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FREQUENCY INVERTER E2000- 0370 T3 37.0KW 75A 400V 423416P
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Input voltage 400V Maximum power 37.0kW Maximum current 75A Warranty -
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FREQUENCY INVERTER E2000- 0450 T3 45.0KW 90A 400V 423417P
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Input voltage 400V Maximum power 45.0kW Maximum current 90A Warranty -
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FREQUENCY INVERTER E2000- 0550 T3 55.0KW 110A 400V 423418P
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Input voltage 400V Maximum power 55.0kW Maximum current 110A Warranty -
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FREQUENCY INVERTER E2000- 0750 T3 75.0KW 150A 400V 423419P
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Input voltage 400V Maximum power 75.0kW Maximum current 150A Warranty -
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FREQUENCY INVERTER E2000- 0900 T3 90.0KW 180A 400V 423420P
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Input voltage 400V Maximum power 90.0kW Maximum current 180A Warranty -
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FREQUENCY INVERTER E2000- 1100 T3 110.0KW 220A 400V 423421P
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Input voltage 400V Maximum power 110.0kW Maximum current 220A Warranty -
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FREQUENCY INVERTER E2000- 1320 T3 132.0KW 265A 400V 423422P
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Input voltage 400V Maximum power 132.0kW Maximum current 265A Warranty -
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FREQUENCY INVERTER E2000- 1600 T3 160.0KW 320A 400V 423423P
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Input voltage 400V Maximum power 160.0kW Maximum current 320A Warranty -
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FREQUENCY INVERTER E2000- 1800 T3 180.0KW 360A 400V 423424P
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Input voltage 400V Maximum power 180.0kW Maximum current 360A Warranty -
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FREQUENCY INVERTER E2000- 2000 T3 200.0KW 400A 400V 423425P
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Input voltage 400V Maximum power 200.0kW Maximum current 400A Warranty -
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FREQUENCY INVERTER E2000- 2200 T3 220.0KW 440A 400V 423426P
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Input voltage 400V Maximum power 220.0kW Maximum current 440A Warranty -
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FREQUENCY INVERTER E2000- 2500 T3 250.0KW 480A 400V 423427P
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Input voltage 400V Maximum power 250.0kW Maximum current 480A Warranty -
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FREQUENCY INVERTER E2000- 2800 T3 280.0KW 530A 400V 423428P
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Input voltage 400V Maximum power 280.0kW Maximum current 530A Warranty -
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FREQUENCY INVERTER E2000- 3150 T3 315.0KW 580A 400V 423429P
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Input voltage 400V Maximum power 315.0kW Maximum current 580A Warranty -
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FREQUENCY INVERTER E2000- 3550 T3 355.0KW 640A 400V 423430P
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Input voltage 400V Maximum power 355.0kW Maximum current 640A Warranty -
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FREQUENCY INVERTER E2000- 4000 T3 400.0KW 690A 400V 423431P
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Input voltage 400V Maximum power 400.0kW Maximum current 690A Warranty -
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Prices are VAT inclusive