V-Curves and Inverted V-Curves – Blogarama, V CURVE OF SYNCHRONOUS MOTOR – ELECTRICAL ENCYCLOPEDIA, V Curves And Inverted V Curves Of Synchronous Motor | Electrical …
4/18/2020 · The inverted V-Curves of synchronous motor shows how the power factor varies with excitation. From inverted V-curves, it is observed that the power factor is lagging when the motor is under excited and leading when it is over-excited. In between, the power factor is unity.
What are V and inverted V curves ? V-curve is a graph between Ia Vs If. Inverted V curve are drawn between cos? Vs If. In the above two cases If (field current) taken on x-axis.We can control the field excitation of synchronous motor by increasing/decreasing the field current.
Such curves obtained by plotting p.f. against If, at various load conditions are called Inverted V-curves of synchronous motor. These curves are shown in the Fig: 2.27 (b). Typically, the synchronous machine V-curves are provided by the manufacturer so that the user can determine the resulting operation under a given set of conditions.
5/7/2020 · ‘V curves’ and ‘inverted V curves’ for Synchronous Motor: V curve: V curve is a plot of the stator current versus field current for different constant loads. The graph is plotted between the armature current Ia and field current If at no load. This curve is known as V curve because the shape of this curve is similar to the letter “V”.
If graph of armature current drawn by the motor (I a) against field current (I f) is plotted, then its shape looks like an english alphabet V . If such graphs are obtained at various load conditions we get family of curves , all looking like V . Such curves are called V – curves of synchronous motor. These are shown in the Fig. 2a.
11/24/2018 · Hence variation in excitation or in field current causes the variation in armature current and curves drawn between armature current and field current for different power inputs are known as “V – curves”. On the other hand ,if the power factor (cos?) is plotted against the field current, the graph looks like an inverted V. The following figures shows the experimental.
6/6/2020 · At the same time the power factor vs field current is called inverted V-curve of a synchronous motor. Just you connect, two three-phase wattmeters and an ammeter to the stator winding of the synchronous motor. Also, connect another ammeter to the field input supply.
7/12/2013 · As against this, if the power factor (cos ?) is plotted against field current (I f), then the shape of the graph looks like an inverted V .Such curves obtained by plotting p.f. against I f, at various load conditions are called Inverted V – curves of synchronous motor.These curves are shown in the Fig. 2(b).
Plot the variations of stator current drawn by the synchronous motor with its field current. 6) Its graph follows shape of V , hence the name V curves . This characteristic of synchronous machine. Variation of power factor with field current of motor in exactly reverse fashion, which is called as inverted V curves .
V – Curves & Inverted V-Curves In Synchronous Motors – MCQs Q1. If graph of armature current drawn by synchronous motor is against field current is plotted then the resulted graph is known as a. V – curves b. Inverted V – curves c. Both (a) & (b) d. …
