Voltage Fluctuations (Dips and Swells) - Remedy, Solutions [Demo]

The solutions for voltage fluctuations (dips and swells) are as various as their causes.
powerqualityonline shows you possible remedies with their advantages and disadvantages.

The Following Measures Can be Taken:

 

1. Increase of Short-Circuit Power

Advantages	Disadvantages
Voltage fluctuation (dips and swells) is reduced if caused by own loads	Usually difficult to realize
Usually no detrimental effect on disconnection conditions	Cost-intensive and complex
Also useful against harmonics and grid resonances	Coordination with owners of upstream grid areas is often required
	No elimination of problem if fluctuation comes from outside
	Metrological support is required to ensure effectiveness and absence of retroactive effects to other loads
	Interruption of operation (downtime) during conversion

The size of the UPS or UPSes must be chosen sensibly in each case. Only use models with passive rectification.

4. Use of Decentralized UPSes at Affected Loads

Advantages	Disadvantages
No intervention in power grid structure	Several devices required
Elimination of mains retroaction and external influences	Possibility of more resonances, depending on rectifier and EMC-filter topology (but this can be prevented by good tuning)
Bridging of voltage failures	No prevention from vagrant currents due to terra neutral combined/separated grid (TN-C-S-grid) problems
More cost effective than a central UPS as the power has to be covered only partially	Result should be checked metrologically

The size of the UPS or the UPSes must be chosen sensibly in each case. For critical power grids (e.g. with commutation dips or other deformations of the voltage) only use models with passive rectification.

5. Use of Voltage Stabilizers for Affected Loads

Advantages	Disadvantages
No intervention in power grid structure
Possibly less expensive than a UPS	Only suitable for low powers
No generation of high frequency	Voltage stabilizers mostly work with magnetic saturation and a 50 Hz oscillating circuit, i.e. there are high losses and high electricity costs
	Unknown performance relating to harmonic loads and possibly already existing grid resonances, therefore measurement is necessary, thus test effort required

 

6.  Connection to Another Supply Point

Advantages	Disadvantages
Very good chance of success when the supply point is selected correctly	Intervention in power grid structure
UPS operation is omitted, thus also possible disturbing influences coming from it	Possibly expensive due to potentially greater distances/cable lengths and possibly earthworks
No problem with surge loads	Result should be checked metrologically

If the power grid is converted as described above, bundled conductors should be used instead of single conductors, since single conductors can lead to unbalanced impedances and vagrant currents due to the induction effect (even if the local terra neutral separated grid structure (TN-S-structure) is correct). Please refer to Unbalance.
The price of this option depends on whether long cable runs with possibly required earthworks have to be laid or whether there is the possibility of easy access to another feed-in.

 

7. Use of Other Devices, ECGs, Converters, Power Supply Units etc.

Avantages	Disadvantages
No intervention in power grid structure	Measurement is required beforehand to find out which devices are specifically affected
No costs for a UPS	Often not realizable because of existing infrastructures or lack of spare components/devices
Avoidence of disadvantages of UPS and voltage constants	Costly as many individual systems have to be checked
	Result/success should be checked metrologically

 This option is very costly because many individual components have to be replaced and it is practically not realizable at all because of existing infrastructures. I