Reactive control power factors

The next step is to apply a number of loss control credit factors such as process control (emergency power, cooling, explosion control, emergency shutdown, computer control, inert gas, operating procedures, reactive chemical reviews), material isolation (remote control valves, blowdown, drainage, interlocks) and fire protection (leak detection, buried tanks, fire water supply, sprinkler systems, water curtains, foam, cable protection). The credit factors are combined and appHed to the fire and explosion index value to result in a net index. 

To optimize this power transfer through reactive control let us study equation (24.10) for the parameters that can be varied to achieve this objective. The active power transfer will depend upon the following factors ... 

However, power systems that cater to almost fixed loads at a time and whose variations occur only at specific times of the day may not reejuire it fast response. In such cases, it is possible to provide manual switching methods which will give enough time between two switchings. Manual switching, how ever, has certain shortcomings, due to the human factor such as its accuracy and diligence, as noted above. The recommended practice is therefore to select fast reactive controls as noted below. 

It was observed in Chapter 4 that capacitor banks must be selected and applied based on power system harmonic studies. This is necessary to eliminate conditions that can actually amplify the harmonics and create conditions that can render the situation considerably worse. One means of providing leading reactive power is by the use of synchronous motors. Synchronous motors applied for power factor control are called synchronous condensers. A synchronous motor normally draws lagging currents, but when its field is overexcited, the motor draws leading reactive currents (Figure 6.11). By adjusting the field currents, the synchronous motor can be made... 

With DC electric motors, power factor correction is sometimes used to improve the power factor of the drive [30]. This is done by incorporating capacitive components into the circuit. Capacitors produce leading reactive power whereas the phase-controlled rectifiers produce lagging reactive power. Thus, by adding appropriately sized capacitors, the power factor of the drive can be improved. 

The special logic for reactivity control, or control rod and/or absorber patterns, together with reactivity values for the control rods, should be stated where necessaiy in order to ensure that the specified limitations for permissible flux dilferences, power peaking factors and power distribution for various modes of normal operation are met. Proper control of flux distributions should ensure that the limiting fuel temperatures and heat flux and the initial conditions assumed in the accident analyses are not exceeded. If appropriate, proper calculational methods or measuring techniques should be provided to enable the reactor operator to confirm compliance. 

The reactive power (power factor) of the power dehvered by the generator is controlled by the generator field current (excitation). 

Unique operating characteristics of fuel cell power plants are as follows. Beneficial operating characteristics of fuel cells saves cost and other benefits include load following, power factor correction, quick response to generating unit outages, control of distribution line voltage and quality control can control real and reactive power independently control of power factor, line voltage and frequency can minimize transmission losses, reduce requirement for reserve capacity and auxiliary electric equipment fuel cells have an excellent part load heat rate and can respond to transmission loads. 

Slider motion (direct reactor reactivity control), Brayton unit speed (reactor coolant flow rate), and HRS flow all represent independent methods of affecting reactivity and are controlled by separate control systems on the spacecraft. To avoid power swings and control oscillations caused by interactions from the respective controllers, only one factor affecting reactivity may be changed at a time. Communication between the respective controllers is imperative. 

The substrate can change the reactivity in the interaction with the reagent by means of its electrophihcity, nucleo-philicity, and hardness [4, 141]. These properties can be accentuated by electroauxiliaries [35] that facihtate electron transfer and direct follow-up reactions. A powerful control is the potential of the elec-trophore that is determined by electronic factors, steric accessibility, and intramolecular electron transfer. This potential can... 

The 3.1% Ak ( 10.6) worth of total swing was calculated for a six-month equilibrium fuel cycle at an 80% load factor. This reactivity change can be compensated by one-half of the control rods (shim rods). The remaining half of the control rods serve as scram rods and are withdrawn from the core during full-power operation (maximum withdrawal... 

Transient power behavior of a nuclear core is determined by a condition known as "reactivity." For a core operating at a steady power level, the various factors that affect reactivity are balanced so that the net reactivity is zero. If the net reactivity is positive, power level will increase and, conversely, decrease if reacfivify is negative. Power control of a PWR is based on balancing reactivity through the use of mechanical and... 

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