of current, voltage and magnetic flux. This decoupled control of
torque and flux component is based on the d-q synchronous
reference frame [70,105]. The vector control system ensures
independent control on DC link voltage, wide range operation
and optimal speed tracking to attain maximum energy [106]. The
various vector control techniques adapted for several applications
[85,107–117] are manifestly tabulated in Table 3. The vector
control is used to maintain the stator frequency constant under
variable speed operation. The active and reactive power is controlled
individually by various vector control techniques presented
in [118–128] and are tabularized in Table 4. During grid fault, the
non-linear control algorithm with direct decoupling helps to
improve the ride through a turbine [129]. Also, the steady state
and dynamic response of electric machines could be improved by
Table 4
Active and reactive power control of hydro generators.
Sl.
No
Control Techniques Machine
Type
Types of Power Electronics Converter Application Year [Ref.
No]
1 Decoupled power controller DFIG Cycloconverter Active and reactive power control 1991 [126]
2 Decoupled controller based position
sensor less scheme
DFIM Bidirectional power flow converter Torque and reactive power control 1995 [120]
3 Decoupled power controller DFIG Single quadrant diode bridge with
controlled converter
Robust torque tracking and reactivepower
regulation
1998 [119]
4 Indirect control DFIG Single quadrant diode bridge with
controlled converter
Maximum active power generation 1999 [125]
5 Decoupled power controller DFIG IGBT based 6-pulse back to back
converter
Optimal active and reactive power
control
2001 [121]
6 Vector control DFIG Bidirectional power flow converter Reactive power control 2001 [122]
7 Stator flux oriented control DFIG Single quadrant diode bridge with
controlled converter
Reactive power control and torque
pulsation compensation
2003 [124]
8 Decoupled power controller DFIG Four quadrant ac-dc-ac power converter Active and reactive powers control
according to the imposed power
limitations
2005 [118]
9 Hopf bifurcation phenomena based
vector-controlled
DFIG Bidirectional power flow converter Active and reactive power control 2006 [128]
10 Direct power control strategy DFIG Back-to-back PWM converter Active and reactive power control 2007 [142]
11 Vector based direct control DFIG Single quadrant diode bridge with
controlled converter
Direct active and reactive power control 2008 [127]
12 Vector