8) This describes the essential skills and knowledge and their level, required for this unit. Evidence shall show that knowledge has been acquired of safe working practices and diagnosing and rectifying faults in energy supply apparatus. All knowledge and skills detailed in this unit should be contextualised to current industry practices and technologies. KS01-TIS69A Electrical power system operations Evidence shall show an understanding of electrical power system operations to an extent indicated by the following aspects: T1 Control of voltage encompassing: Conditions leading to voltage collapse and system disintegration. Effects on the system of high/low volts Voltage control devices - voltage regulators applied to generators and synchronous phase modifiers, electromagnetic voltage regulators, series and parallel capacitors, OLTC transformers and static Var compensations (SVCs) such as saturated reactor compensations (SRs), thyristor controlled reactor compensators (TCRs), combined TCR/TSCs and the production of wave-form distorting harmonics and control devices. T2 The importance of the location in the system of voltage control devices. T3 The use of graphical methods to calculate the size of VAr regulating plant. T4 Control of power encompassing: Base load and spinning reserve Regulating machines Rapid start plant, Phase shifting transformers and various forms of load shedding. Principles and practices of automated control of individual machines Stations and transmission/tie-line elements. Synchronising power T5 The relationship between power and frequency encompassing: Limiting values Machine stabilising - steam by-pass, rapid valving, slip stabilisers and over speed limiting. Use of single pole generator CB's. Use of machine AVR's as angular stabilisers. Damped and un-damped system oscillations. Relationship between fault clearance times and system stability. Calculation of critical clearance angles based on equal area criteria. T6 Types of communication systems encompassing: Telephone, power line carrier, dedicated cable, microwave links and fibre optics. Quantities and signals to be communicated. Advantages and disadvantages of the various systems. Equipment requirements. T7 Transient over-voltages in power systems encompassing: Switching and lightning overvoltages and their effect on different plant items. Transient over-voltage control and reduction using surge diverters, shield wires and CB are control. Insulation systems, insulation coordination, insulation grading in plant items, bushings and capacitor bushings. T8 Factors leading to the generation of corona encompassing: Consequences of corona. Reduction of corona Conductor bundling, grading rings and conductor surface treatment. T9 Power System Protection encompassing: Location of CT's in major plant items. Earthing principles and devices. Fault current control/limitation using neutral earthing compensators (NEC's), neutral point earth impedances, high conductivity shield wires and parallel feed interlocking. Application of different types of protection. |