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A diagram with multiple synchronous machine curves; open-circuit saturation curve is the leftmost one The open-circuit saturation curve (also open-circuit characteristic, OCC) of a synchronous generator is a plot of the output open circuit voltage as a function of the excitation current or field.
synchronous presettable 4-bit up/down decade counter 16 DM74LS168: 74x169 1 synchronous presettable 4-bit up/down binary counter 16 SN74LS169B: 74x170 1 16-bit register file (4x4) open-collector 16 SN74170: 74x171 4 quad D flip-flops, clear 16 SN74LS171: 74x172 1 16-bit multiple port register file (8x2) three-state: 24 SN74172: 74x173 4
In a synchronous generator, [1] the short circuit ratio is the ratio of field current required to produce rated armature voltage at the open circuit to the field current required to produce the rated armature current at short circuit. [1] [2] This ratio can also be expressed as an inverse of the saturated [3] direct-axis synchronous reactance ...
Synchronous impedance curve (short-circuit characteristic curve), showing armature current as function of field current. The curve is obtained by rotating the generator at the rated RPM with the output terminals shorted and the output current going to 100% of the rated for the device (higher values are typically not tested to avoid overheating ...
A 4-bit synchronous counter using JK flip-flops. In a synchronous counter, the clock inputs of the flip-flops are connected, and the common clock simultaneously triggers all flip-flops. Consequently, all of the flip-flops change state at the same time (in parallel). For example, the circuit shown to the right is an ascending (up-counting) four ...
The sequence of events is similar for manual or automatic synchronization. The generator is brought up to approximate synchronous speed by supplying more energy to its shaft - for example, opening the valves on a steam turbine, opening the gates on a hydraulic turbine, or increasing the fuel rack setting on a diesel engine. The field of the ...
The important point in modeling synchronverter is to be sure that it has similar dynamic behavior to Synchronous generator (see figure 3). This model is classified into 2-order up to 7-order model, due to its complexity. However, 3-order model is widely used because of proper compromise between accuracy and complexity. [14] = (+.) +.
Due to high cost of a generator, a set of sensors and limiters will trigger the alarm when the generator approaches the capability-set boundary and, if no action is taken by the operator, will disconnect the generator from the grid. [3] D-curve expands with cooling. The D-curve for a particular generator can be expanded by improved cooling.