Power supply control systems

One of the outstanding features of fluid power systems is that force, generated by the power supply, controlled and directed by suitable valving, and transported by lines, can be converted with ease to almost any kind of mechanical motion. Either linear or rotary motion can be obtained by using a suitable actuating device. 

The process is carried out in an air-tight chamber—originally a simple bell jar and now normally in commercial production purpose-built plant some metres in diameter and length. The chamber is fitted with the necessary pumping system, work holder, source holder, power supply, control equipment, and gauges. It is possible for an experienced operator to control the process with the precision necessary but for routine production to a specified standard automatic control is regarded as essential. 

Electrochemistry involves the contact between different materials which conduct electricity. The two terminals in the electrochemical system linked to the external control device must be electronic conducting materials if the electric parameter is to be controlled, for instance using a direct current (DC) power supply. This system must also include at least one ionic conducting material. To illustrate, an electronic n/p junction... 

Power and control systems associated with containment isolation are multichaimel, fail-safety. Failure of a single sensor circuit or system component does not prevent normal protective action. Separate routes from different, reliable power sources feed two valves in the same line. Control power and motive power for an electrically operated valve are supplied from the same source. 

Figure 8-17 Fuel cell power conditioner control system for supplying power to the utility... 

Use a separate dc power supply or separate ac branch circuit to power each control system. When a power source is shared, the line impedance (ac supply) or current capability (dc supply) must be sufficient to maintain rated voltage under all loading conditions. 

The Class IE dc and munterraptible power supply (UPS) system (IDS) provides lehable power for the safety significant equipment required for the plant instrumentation, control, monitoring, and other vital fimctions. In addition, the class IE dc and UPS system provides power to the emergency lighting in the main control room and at the remote shutdown woikstation. 

Fig. 5.14 The ABB-Membrel process for electrolytic generation of ozone using a solid polymer electrolyte, (a) Schematic of the Membrel cell, (b) A complete ozone treatment unit including a circulating system, UV lamps, control panel and power supply. The system is used to deliver up to 2 m h ultrapure water to a pharmaceutical production plant. Ozone is produced by a single Membrel cell of 30 cm active electrode area. The cell is shown by an arrow. (Photographs courtesy Asea Brown Boveri Ltd.)...

The types of disturbances for each type of equipment are categorized in Table 6.7a. It is clear from the table that halts and locks (freezes) of equipment make up about half of the total disturbances, and those including malfunctions (not operated too) constitute 70% of the total disturbances. These disturbances result in troubles of power supply and system operation as shown in Figure 6.5. For example, more than 10% of the control circuit disturbances cause power system troubles. As long as a control equipment disturbance is contained within a control circuit, the disturbance does not cost much. However, if it affects power system operation, it becomes an urgent and significant problem. More than one-third of control equipment disturbances affect generation, power supply, and system operation at the same time. 

SO much. However, if it affects the power system operation, it becomes an urgent and very significant problem. It is noted that more than one-third of control equipment disturbances cause troubles at the same time of generation, power supply, and system operation. 

The HILL-SCAN 30XX boards can be used in different PCs. Desktop- and tower-PCs as well suited for laboratory uses. For in-field inspections rugged notebooks and portable PCs are advantageous. A typical portable system is shown in Fig. 2 (USPC 3010), used in MUSE (Mobile Ultrasonic Equipment). This portable PC not only contains the boards for ultrasonic testing but also a controller with power supply for stepper motors, so that a manipulator can be connected directly. The MUSE system is enlarged with a water circulation system which enables a local immersion technique" for in-field inspections. A typical result is shown in Fig. 3, which presents a D-scan of a CFRP- component in RTM-techniques. The defect area caused by an impact is clearly indicated. The manipulator is described in [3]. 

In addition to the controlling computer the system contains only a small control unit - PSP-4 (weight approx. 5 kg.) which among other system components includes a motor control system integrated closely with the PS-4 ultrasonic system. For communication between the PSP-4 control unit and the robot as well as robot power supply is used a single cable less than 10 mm. in diameter. 

The electronic block, which includes block of the analysis and registration and control system engines, and block of the source-receiver of acoustic oscillations are universal for any installations of this type. As the source-receiver of acoustic oscillations the ultrasonic flow detector is usually use. It s, as a rule, the serial devices for example y/f2-12. The electronic block contains the microprocessor device or PC, device of the power supply and management of engines... 

Power Supplies and Controls. Induction heating furnace loads rarely can be connected directiy to the user s electric power distribution system. If the load is to operate at the supply frequency, a transformer is used to provide the proper load voltage as weU as isolation from the supply system. Adjustment of the load voltage can be achieved by means of a tapped transformer or by use of a solid-state switch. The low power factor of an induction load can be corrected by installing a capacitor bank in the primary or secondary circuit. 

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. 

Our present discussions relate only to the laboratory testing of safety-related secondary systems, as are employed in critical areas such as areas of emergency power supply and reactor power control supply etc. of a nuclear power plant (NPP) according to IEEE 344 and lEC 60980. There are other codes also but IEEE 344 is referred to more commonly. Basically, all such codes are meant for an NPP but they can be applied to other critical applications or installations that are prone to earthquakes. 

A few TCRs to balance the reactive power supply. They may generate harmonics, which must be suppressed to avoid any resonance. T.SCs and TCRs are monitored through a feedback control system,... 

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