CEE Relays Ltd.

87C Whitby Road, Slough, SL1 3DR

Telephone: (01753) 576477        Fax: (01753) 825661

Website: www.ceerelays.co.uk

At CEE Relays Ltd., our experienced Engineers use the latest state-of-the-art software (SKM System Analysis Software) to carry out a full range of power system analysis studies. We can either carry out the full study or validate your existing results. Studies that we can carry out include :

Load-flow and Voltage-drop Analysis

If you are worried about the ability of your network to supply the load, then we can carry out a load-flow and voltage-drop analysis. We will check that all the components (cables, transformers and generators) can supply enough current to keep the network running and also that the voltage drop at each busbar is within acceptable limits.

Motor Starting Analysis

If you are worried that you will not be able to start your largest motor, or are worried that you will have to place a limit on the number of motors that you can start at one time then we can carry out a Transient Motor Starting Study. This will model the voltage drop and recovery when motors are started. We can also show the effect on the speed of running motors when a large motor is started.

Fault Analysis and Equipment Evaluation

We can calculate the fault level at every point in your network to the IEC60909 standard. This will allow us to check the ratings of your busbars and circuit breakers.

Protection co-ordination

Using the results from both the load-flow and fault-level studies, we can recommend settings for your protection relays. We will choose settings to ensure that faulty or overloaded equipment is isolated as quickly as possible, while ensuring that healthy plant is kept running and that the relays do not trip unnecessarily.

Dynamic Analysis

Quite often running a load-flow and fault-level analysis is not sufficient and (especially where isolated networks are concerned), the dynamics of a network need to be modelled. We can model the network’s response to many different events including faults, load changes, loss of generation, switching and motor starting.

The drop in frequency (as well as the drop in voltage) is modelled when a motor is started. The voltage and frequency is then seen to recover as the governor takes time to react to the system disturbance.

We can also determine the critical fault switching times to maintain system stability.

Harmonic Analysis

Modern power systems have more problems with harmonics than ever before. Using measurements of the harmonics at certain points throughout your network, we can calculate the total harmonic distortion (THD) at any point in the network, to determine whether the THD is within the specified limits.