Cosphi compensation  White paper
What is Cos Phi?
What does Cos Phi mean? Cos Phi indicates how much power is lost during the 'transport' of power. The ratio of actual power vĩ đại apparent power is Cos Phi. The current is out of phase with respect vĩ đại the voltage. This causes reactive power.
Bạn đang xem: cos phi
Reducing reactive power
In addition vĩ đại actual power, cables, lines and transformers must also transport reactive power. Reactive power is the loss of energy. If you want vĩ đại use the infrastructure more efficiently or are at the limit of your connection capacity, it is interesting vĩ đại reduce your reactive power ví that you can still "grow" without expanding your installation. You may also have vĩ đại pay your grid operator extra for the transported reactive power.
What is reactive power?
Active and reactive energy
The purpose of the electricity grid is vĩ đại transport energy from the source vĩ đại the consumer. The energy consists of active energy (Pw) and reactive energy (Pb). Active energy is converted into mechanical energy (motor), light (lamp) or thermal energy (heat or cooling). Reactive energy is used vĩ đại maintain the magnetism of transformers, ballasts and gas discharge lamps. As a result, current and voltage are not in phase.
Phase shift  Tracking of current
In an inductive load, the current "jumps" on the voltage. The degree vĩ đại which the current rushes in response vĩ đại the voltage is indicated by phi, or the letter Φ. Phi is the angle between voltage and current. In addition vĩ đại phase shift, in some cases reactive power can also be caused by mains pollution (harmonics).
Phase shift voltagecurrent cos phi
Sensible energy
The figure below shows that only active energy, the actual power, is meaningful (the beer). The reactive power is not converted into meaningful energy (the foam). If we add up the beer and the foam, we get the minimum size of the glass. In energy technology, if we add up the actual power and the reactive power, we get the minimum required capacity of the electrical infrastructure. The more reactive power, the more copper, transformer and connection capacity is required.
Blinding power compensation
Working factor cosΦ
The ratio of real power vĩ đại apparent power is the power factor or cosine phi (cosΦ). Cos Phi can be improved with Cos Phi Compensation. Cos Phi is calculated as follows:
Workingfactor = Pw / Ps = cosΦ (bij 50 Hz)
Reactive power generated by harmonics
The increase in electronic loads such as frequency converters, electronic power supplies and LED lighting causes more and more harmonic contamination. Harmonic pollution causes additional reactive power.
What is harmonic?
A harmonic is a frequency that is an integer multiple of the fundamental frequency. The fundamental frequency is the lowest (natural) frequency that a system naturally exhibits. An eigenfrequency of a system is a frequency that the system can naturally exhibit. Read more about higher harmonics.
Active filter
The ratio of real vĩ đại apparent power at all frequency components is the power factor. If higher harmonics in the voltage network cause problems or increase the apparent power, it is best vĩ đại use an active filter. We explain this in more detail in our White Paper on active filters We will tell you more about this. The power factor is calculated as follows:
Powerfactor = Pw / Ps (at all frequency components)
Consequences of a poor CosPhi
 Overloading and overheating of the electrical installation.
 Higher connection value with the grid operator than vãn necessary.
 Percentage load per room, rack or circuit.
 Unintentional switching off of installation circuit breakers and therefore processes.
 A fine from the energy company and a higher energy bill than vãn necessary.
 A high energy bill.
Cos Phi compensation  Reducing reactive current
Improving the cosphi, or reducing the reactive current, soon makes sense. In addition, compensating the cosphi has a number of positive sideeffects:
 Compensation for minor interruptions and transients, which increases reliability.
 More optimal use of connection capacity.
 Compensation of varying loads.
 Filtering of harmonics (up vĩ đại 5th and 7th, above active filtering).
 Strong reduction of CO² emissions.
Where vĩ đại compensate for blind current?
Load compensation
Xem thêm: bàn ủi philips
Decentralised compensation (i.e. installation of the cosphi compensation at the load) is generally recommended for consumers with an individual load of more than vãn 25 kW that are almost always in operation, such as large fans, hammer mills and transformers with a relatively stable load.
Compensation at the main distributor
Centralised compensation (i.e. installation of the compensation at the main distributor) is recommended where the load varies. An automatically controlled compensation ngân hàng is almost always chosen in such cases.
Decentralised versus centralised cosphi compensation
Read more about reducing reactive power in our white paper
Types of compensation banks Cos Phi compensation
In standard situations, we always recommend using tuned compensation banks for Cos Phi compensation. These compensation banks filter out harmonics and protect the TF signal of the power company from short circuits.
1. Nonregulated, tuned compensation ngân hàng (with coils)
An unregulated, tuned compensation ngân hàng is often used for motors with a relatively high power and mains transformers with a relatively stable load.
2. Regulated compensating ngân hàng with tuning
We recommend a regulated compensation ngân hàng with adjustment for situations where compensation is centralised and the load can vary. The capacity of a regulated compensation ngân hàng is matched exactly vĩ đại the amount of compensation capacity required, using the Janitza Prophi controller. In this way, overcompensation is prevented and the mix is universally applicable.
3. The thyristorcontrolled compensation ngân hàng with tuning
The thyristorcontrolled compensation banks are used in situations where the load changes quickly, such as welding lines, lift systems, cranes and injection moulding machines. The thyristors switch quickly and precisely on the zero crossing of the current. This means that the load is monitored quickly and precisely, preventing under or overcompensation.
Read more about active filters for cos phi compensation
Seven questions for cos phi compensation
With cosphi compensation, you can save a lot of costs. Incorrect application of this compensation can lead vĩ đại problems such as over or undercompensation, problems with the power company or overload, damage or even fire. This is why we provide you with good advice, in which the following questions are important:
1. In which environment is the CosPhi compensation applied?
 Industry
 Office
 Clean process industry
2. Is there room vĩ đại put the compensation away?
 The physical space for placing the compensation.
 Moisture and dirt are bad for the compensation.
 The room must not become too hot.
3. Is there room on the distributor vĩ đại connect the compensation?
 Three phases and one earth are required vĩ đại connect the compensation.
 Consider the correct application of fuse ratings and cable cross sections of the compensation.
4. What kind of transformer should be used for compensation?
 How many kVA is the transformer?
 What is the shortcircuit voltage of the transformer (in % on the type plate)?
 Are there any transformers in parallel?
5. What kind of load is there on the installation vĩ đại be compensated?
 Rapidly changing loads? (spot welding machine, crane), then thyristorcontrolled compensation.
 Is there a lot of mains pollution? (frequency regulators, switching power supply, etc. welding equipment)
6. What is the frequency of the present tone frequency signal?
 How many Hz is the TF signal? Your network operator knows the answer vĩ đại this.
7. Is the controller easy vĩ đại connect?
 One current transformer is required for the Janitza controller. Can this be used?
 Can the current transformer be shortcircuited?
 Is there a safe measuring voltage?
Table  Fuse ratings and cable crosssections
PFC Cable diameter, fuse rating (for 400V/50Hz) nets
Vermogen in kvar  Nominale stroom in A  Kabeldiameter& NYYJ mm²  HRC fuse value 
5  7  4x 2,5  16 
7,5  10  4x 4  20 
10  14  4x 4  25 
12,5  18  4x 6  35 
15  22  4x 6  35 
17,5  25  4x 10  50 
20  29  4x 10  50 
25  36  4x 16  63 
30  43  4x 16  80 
37,5  54  4x 25  100 
50  72  3x 35/16  125 
5565  7994  3x 35/16  160 
7085  101123  3x 70/35  200 
86100  124145  3x 95/50  250 
101125  146181  3x 120/70  250 
126160  182231  2x 3x 70/35  315 
161180  233260  2x 3x 95/50  400 
181200  261289  2x 3x 120/70  400 
201250  290361  2x 3x 150/70  500 
251300  362434  2x 3x 185/95  600 
Cable diameters only suitable for the capacitor capacities specified

Bình luận