FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See Section 10 and Rule 13)
SENSOR-LESS IPMSM DRIVE FOR PV FED
PUMP
APPLICANT: Ecofrost Technologies Private Limited
AN INDIAN COMPANY HAVING ADDRESS AT
Survey No.134/1,134/2,130/0, Jeevan Nagar Katraj Road, Tathawade, Pune, Maharashtra-411033, INDIA
THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE SUBJECT MATTER AND THE MANNER IN WHICH IT IS TO BE PERFORMED.

TECHNICAL FIELD
[001] The present disclosure relates generally to a sensor-less IPMSM drive for PV fed pump and more particularly to the sensor-less IPMSM drive for PV fed pump with electrical and electronic configuration.
BACKGROUND
[002] The solar panel or photo voltaic (hereinafter referred as PV) panel has various applications. The most common use of the PV panel is in agricultural water pumping motor application. There are different motors available in the market to drive the pump as per applications and benefits. An induction motor is the most common and widely used motor. The induction motor is operated in open looped system. The induction motor requires large space and is bulky for small operations like water pumping. The induction motor has higher copper losses as it uses the copper windings on the stator and rotor. For such small and specified agricultural water pumping, the internal permanent magnet synchronous motors (here after it is referred as IPMS motor) are widely used, as the IPMS motor has high efficiency and high-power density as compared to induction motor. The IPMS motors are AC synchronous motors. The IPMS motor’s field excitation is provided by permanent magnets. The required rotor speed in IPMSM is achieved through a closed loop vector controller module. A sensor-less closed loop vector controller module is operated in the closed loop, which requires the information of the rotor position. The sensor-less closed loop vector controller module uses a position encoder to sense the angular position of rotor and the rotor speed. The position encoder can be excluded if an estimator is used for finding the rotor position. Further, the sensor-less closed loop vector controller module is based on the stator currents, the stator fluxes and the back EMF. When IPMS motor is operated

without the LC filter at the output of the voltage source inverter, the IPMS motor draws higher harmonic currents causing higher core losses in the motor. The losses are considerable when the voltage source inverter is operated at high switching frequency.
SUMMARY [003] Embodiments of the present disclosure present technological improvements as solutions to one or more of the above-mentioned technical problems.
[004] Before the present subject matter relating to a sensor-less IPMSM drive for a PV-fed pump, it is to be understood that this application is not limited to the particular system described, as there can be multiple possible embodiments that are not expressly illustrated in the present disclosure. It is also to be understood that the terminology used in the description is to describe the implementations or versions or embodiments only and is not intended to limit the scope of the present subject matter.
[005] In an embodiment of a present invention, a sensor-less internal permanent magnet synchronous (IPMS) motor drive for PV fed pump is disclosed. The sensor-less IPMS motor drive for PV fed pump includes a voltage source inverter and an LC filter. The voltage source inverter is electrically connected to a PV panel. The PV panel provides DC voltage and DC current to the voltage source inverter. The LC filter is electrically connected to the voltage source inverter, a sensor-less closed loop vector controller module, and an IPMS motor such that the LC filter is placed at the output of the voltage source inverter to receive current and provide a filtered phase output voltage and a filtered phase output current to the sensor-less closed loop vector controller module and to the IPMS motor. The sensor-less closed loop vector controller module is electrically connected to the LC filter, the PV panel, and the voltage source inverter such that the sensor-less closed loop vector controller module receives the

first input as filtered phase voltage and filtered phase current from the LC filter and receives second input as DC voltage and DC current from the PV Panel, as the PV panel is an aid to estimate the angular position of rotor by estimating the plurality of stationary stator flux component and stationary stator current components and provide output as a pulsating voltage signal to the Voltage Source Inverter.
[006] This summary is provided to introduce aspects related to a sensor-less IPMSM drive for PV fed pump. This summary is not intended to identify essential features of the claimed subject matter nor is it intended for use in determining or limiting the scope of the present subject matter.
BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS
[007] The foregoing detailed description of embodiments is better understood when read in conjunction with the appended drawings. For the purpose of illustrating the disclosure, there are shown in the present document example constructions of the disclosure; however, the disclosure is not limited to the specific system or method disclosed in the document and the drawings.
[008] The present disclosure is described in detail with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to refer to various features of the present subject matter.
[009] Figure 1 illustrates a block diagram depicting electrical connections of various components for working of a sensor-less IPMSM drive for PV fed pump, in accordance with an embodiment of the present subject matter. [0010] Figure 2 illustrates a block diagram depicting closed loop vector controller module, in accordance with an embodiment of the present subject matter.

[0011] Figure 3 illustrates a block diagram depicting flux & position
estimator, in accordance with an embodiment of the present subject matter.
[0012] Figure 4 illustrates a flowchart depicting working of closed loop
vector controller module, in accordance with an embodiment of the present
subject matter.
[0013] Figure 5 illustrates a block diagram depicting a current controller, in
accordance with an embodiment of the present subject matter.
[0014] Figure 6 illustrates a block diagram depicting coordinate
transformation of a sensor-less closed loop vector controller module, in
accordance with an embodiment of the present subject matter.
[0015] In the above accompanying drawings, a non-underlined number
relates to an item identified by a line linking the non-underlined number to
the item. When a number is non-underlined and accompanied by an
associated arrow, the non-underlined number is used to identify a general
item at which the arrow is pointing.
[0016] Further, the figures depict various embodiments of the present
subject matter for purposes of illustration only. One skilled in the art will
readily recognize from the following discussion that alternative
embodiments of the structures and methods illustrated herein may be
employed without departing from the principles of the present subject
matter described herein.
DETAILED DESCRIPTION
[0017] Some embodiments of this disclosure, illustrating all its features, will now be discussed in detail. The words "comprising," "having," "containing," and "including," and other forms thereof, are intended to be equivalent in meaning and be open ended in that an item or items following any one of these words is not meant to be an exhaustive listing of such item or items, or meant to be limited to only the listed item or items. It must also be noted

that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise. Although a sensor-less IPMSM drive for PV fed pump, similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the exemplary, a sensor-less IPMSM drive for PV fed pump is now described.
[0018] Various modifications to the embodiment will be readily apparent to those skilled in the art and the generic principles herein may be applied to other embodiments. For example, although the present disclosure will be described in the context of a sensor-less IPMSM drive for PV fed pump, one of ordinary skill in the art will readily recognize that a system can be utilized in any situation, such as in an agricultural implementation as water pumping application. In an IPMS motor stator current reduces the core loss and the water output from the pump per unit input DC power is increased. Thus, the present disclosure is not intended to be limited to the embodiments illustrated but is to be accorded the widest scope consistent with the principles and features described herein.
[0019] In an embodiment, a sensor-less IPMSM drive for PV fed pump is disclosed. The PV panel is used in agricultural water pumping motor applications. Different motors are used to drive the motor as per applications and benefits. The induction motor has higher copper losses as it uses the copper windings on the stator and the rotor. For a specified agricultural water pumping application, the internal permanent magnet synchronous motor (hereafter referred to as IPMS motor) is used, as the IPMS motor has higher efficiency and higher power density as compared to the induction motor. The IPMS motor is an AC synchronous motor. The IPMS motor’s field excitation is provided by permanent magnets. The rotor speed and position estimation in IPMSM is achieved through a closed-loop vector controller module. A closed-loop vector controller module is

operated in a closed loop, which requires the information of the rotor position. The sensor-less closed loop vector controller module uses a position estimator to estimate the angular position of the rotor and speed estimation. The sensor-less closed loop vector controller module eliminates the use of a position encoder. To estimate the angular position of the rotor and speed, the sensor-less closed loop vector controller module uses stationary stator flux, stator current, and back EMF (electro-motive force). When operated without the LC filter at the output of the voltage source inverter, the IPMS motor draws higher harmonic currents causing higher core losses in the motor. The losses are considerable when the voltage source inverter is operated at high switching frequency.
[0020] A sensor-less IPMSM drive for PV fed pump is used to drive an interior permanent magnet synchronous motor (three-phase synchronous motor). The IPMS motor drive includes a PV panel, a voltage source inverter, an LC filter, an IPMS motor, and a sensor-less closed-loop vector controller module. The PV panel provides DC voltage and DC current to the voltage source inverter and to the closed loop vector controller module. The sensor-less closed loop vector controller module takes the input from the PV panel as the DC supply and from the LC filter as the 3-phase inverted AC voltage and current and provides output to the voltage source inverter as the pulsating stimulus output voltage. The sensor-less IPMSM drive uses a filtered output signal given to the sensor-less closed loop vector controller module and to the IPMS motor.
[0021] The sensor-less closed loop vector controller module comprises a maximum power point tracking (hereafter referred to as MPPT), a torque controller, a subtraction unit, a current controller, a space vector pulse width modulation (hereafter referred as SVPWM), a voltage converter, a current converter, a flux and position estimator. The MPPT is used to obtain

the reference DC voltage (Vdc*) from the DC voltage and DC current as output of the PV panel.
[0022] The torque controller is placed at the output of the MPPT. The torque controller takes input as the actual DC voltage and the reference DC voltage to obtain the reference stator current (Is*). The torque controller has a mechanism for generating the required current (Is*). The generated reference stator current (Is*) corresponds to the torque of an electric motor. A direct-axis (herein referred to as d-axis) stator current (Id*) is obtained from the reference stator current (Is*) using maximum torque per ampere (hereafter referred to as MTPA). The d-axis stator current corresponds to an excitation current of the interior permanent magnet motor. This current command (Id*) is output to the MTPA. The subtraction unit is placed at the output of the MTPA. The subtraction unit takes input d-axis stator current (Id*) and the reference stator current (Is*) to calculate a quadrature-axis reference (herein referred to as q-axis) stator current (Iq*). The subtraction unit generates the reference q-axis stator current (Iq*) of the dq transformation by calculating a square root of a subtraction of the square values of the reference d-axis stator current (Id*) and the reference stator current (Is*). The necessary current to produce the desired amount of torque reference, q-axis stator current (Iq*), is obtained using the subtraction unit as,
√(𝐼𝑠∗)(𝐼𝑠∗)−(𝐼𝑑∗)(𝐼𝑑∗) [0023] The torque controller comprises a proportional integrator (PI) controller 1 that uses the actual DC voltage (Vdc) and the reference DC voltage (Vdc*) to calculate a reference q-axis stator current (Iq*). [0024] The current controller comprises a photo voltaic (hereinafter referred as PV) 2 for the d-axis and a third PI controller for the q-axis. The reference d-axis stator current (Id*) and the actual d-axis stator current (Id) using Second PI controller determine the reference stator voltage (Vd*). The third

PI controller uses the reference stator current of the q-axis and the actual stator current of the q-axis to determine the reference stator voltage (Vq*). [0025] The sensor-less closed-loop vector controller module further has a clarke transformation, a park transformation, and a park inverse transformation to implement transformation between three coordinate systems in the IPMS motor, including a three-phase stationary (a-b-c) coordinate system, a two-phase stationary (α - β) coordinate system, and a two-phase synchronous rotating (d-q) coordinate system, which are coordinate system commonly used in the IPMS motor. [0026] The d-axis current controller calculates the reference stator voltage Vd* on the dq coordinate axis so that the current deviation becomes zero. The q-axis current controller calculates the reference stator voltage Vq* on the dq coordinate axis so that the current deviation becomes zero. The output of the q-axis current controller and the reference stator voltage Vd* which is the output of the d-axis current controller are inputs to the dq inverse-transformation device.
[0027] The first co-ordinate transformation and the second co-ordinate transformation use the clarke and the park transformation to transform the current and voltage coordinates from the a-b-c coordinate system to the rotating alpha-beta (herein referred to as α - β) coordinate system, so that three-phase current and three-phase voltage of the IPMS motor is detected as Ia, Ib and Ic into the alpha axis-component of the stator current Iα and beta axis-component of the stator current Iβ. And VA, VB, VC transform into the alpha-axis component of the stator current Vα and the beta axis-component of the stator current Vβ.
[0028] The clarke transformation is configured to transform the current coordinate from the a-b-c coordinate system to the rotating alpha-beta (herein referred to as α - β) coordinate system, so that the three-phase current of the IPMS motor is detected as Ia, Ib and Ic transform into the

alpha axis-component of the stator current Iα and beta axis-component of the stator current Iβ.
[0029] The park transformation is configured to transform the coordinates from the alpha-beta (α-β) coordinate system to the d-q coordinate system to transform an alpha-axis component of the stator current (Iα) and beta-axis component of the stator current (Iβ) converted into motor d-axis stator current (Id) and q-axis stator current (Iq).
[0030] The dq inverse-transformation device is configured to transform the reference stator voltage Vd*, Vq* of the dq coordinate system onto the three-phase alternate current coordinate. The dq inverse-transformation device performs transformation into control signals SA, SB, SC of the three-phase alternate current coordinate system based on the received voltage commands Vd*, Vq*, and the output θ of the position estimation. The dq inverse-transformation device transforms the reference stationary voltage (Vα*, Vβ*) to the stationary voltage (Vα, Vβ) and the transformation outputs are provided to the SVPWM generation.
[0031] The closed-loop vector controller module senses the DC voltage and DC current from the PV panel. The DC voltage (Vdc) and DC current (Idc) extract MPPT and generate the reference DC voltage (Vdc*). The torque controller uses the DC voltage (Vdc) and the reference DC voltage (Vdc*) to estimate the reference stator current (Is*) at the desired rotation. The MTPA is used to obtain the output as maximum torque under constant reference stator current (Id*) from the reference stator current (Is*). The 3-phase currents are transformed into the rotatory (d-q axes) current using the converter unit and the rotatory (d-q axes) voltage transforms into stationary (α-β) voltage (Vα*, Vβ*). The stationary (α-β) voltage and current are used to obtain the stator flux and angular position of the rotor. The alpha-beta coordinate system Vα and Vβ, transforms into the pulsating stimulus voltage sent into the SVPWM. The SVPWM adopts the space voltage vector

pulse width modulation algorithm according to stator voltage Vα and Vβ to generate pulse width signal input to the voltage source inverter. [0032] The dq transformation device is configured to transform IA, IB, IC which are reproduced values of the phase currents of the motor into Id, Iq on the dq coordinate which is the rotation coordinate axes. The transformed Id and Iq are used for deviation calculation of the current command Id* and the current command Iq* by the subtraction unit.
[0033] The phase current and pole voltage of the IPMS motor is converted into the stationary αβ reference voltage (Vα, Vβ) and current (Iα, Iβ). The stator flux αβ component along with stationary αβ reference current (Iα, Iβ) are used to estimate the rotor position (angular position) (θ). The estimated angular position is passed through a derivative block to find out the instantaneous speed (ώ) and the angular speed (ω) of the IPMS motor with a low pass filter.
[0034] The angular velocity (ω) is the rotation speed of the interior permanent magnet synchronous motor in electrical radians per second from the estimated value of angular position θ of the rotor. This estimated (rotation speed) angular speed ω is used for monitoring the frequency of the IPMS motor drive.
[0035] The proportional integrator (PI) controller also uses the dq-axis stator current (Id, Iq) and the reference dq-axis stator current (Id*, Iq*) to calculate the reference dq-axis stator voltage (Vd*, Vq*). The reference dq-axis stator voltage (Vd*, Vq*) is converted to the αβ component using an inverse park coordinate transformation. The space vector pulse width modulation unit is configured (hereinafter referred as SVPWM) to generate a pulsating stimulus from the reference αβ component. The generated pulsating voltage is given to the voltage source inverter. [0036] The voltage source inverter converts DC current and voltage into the AC current and voltage with the desired amplitude. The phase current and

the phase voltage are filtered using the LC filter. The 3-phase filtered
voltage and current is fed to drive the IPMS motor. The voltage source
inverter generates the three-phase current according to the pulse width
signal and the three-phase current is filtered using the LC filter. The LC
filtered output is sent to the IPMS motor and to the sensor-less closed loop
vector controller module.
[0037] During the operation in a first stage, the MPPT is used for obtaining
the reference DC voltage (Vdc*) from the DC voltage and the DC current
obtained as output of the PV panel.
[0038] In a second stage, the torque controller is used to obtain the reference
stator current (Is*) from the actual DC voltage and the reference DC voltage.
[0039] In a third stage, MTPA uses the reference stator current (Is*) to obtain
the direct-axis (herein referred to as d-axis) stator current (Id*).
[0040] In a fourth stage, the square of the d-axis stator current (Id*) and the
square of the reference stator current (Is*) are subtracted to calculate the
quadrature-axis reference (herein referred to as q-axis) stator current (Iq*).
[0041] In a fifth stage, the three-phase voltage and the three-phase current
(VA, VB, VC and IA, IB, IC) transform the coordinate into a two-phase
stationary (α - β) voltage and current component.
[0042] In a sixth stage, the two-phase stationary (α - β) current component
transforms the coordinate into a two-phase synchronous rotating (d-q)
current component.
[0043] In a seventh stage, the two-phase stationary (α - β) voltage and
current are used to calculate the stator flux, using a flux estimation unit.
[0044] In an eighth stage, the stator flux and the two-phase stationary (α -
β) current component are used as input to the position estimation and the
angular position θ is obtained.

[0045] In a ninth stage, the angular position θ is used to obtain the angular
velocity ώ and its filtered angular velocity ω is obtained using the low pass
filtering unit.
[0046] In a tenth stage, the angular position, the reference stationary current
component (Id*, Iq*) and the stationary current component (Id, Iq) are used
to calculate the reference dq-axis stator voltage (Vd*, Vq*) using the current
controller.
[0047] In an eleventh stage, the reference dq-axis stator voltage (Vd*, Vq*)
are used to drive the input pulsating voltage to the SVPWM.
[0048] In a twelfth stage, the pulsating voltage signal is given to the voltage
source inverter to generate the three-phase pulsating voltage at the
switching frequency according to the pulse width signal.
[0049] In a thirteenth stage, the three-phase voltage from the voltage source
inverter is filtered using the LC filter.
[0050] In a fourteenth stage, the LC filtered output which is three phase
filtered voltage is sent to the IPMS motor.
[0051] In a fifteenth stage, the filtered 3-phase voltage across the IPMS
Motor draws phase currents. The LC filter eliminates a major portion of
harmonics and delivers sinusoidal voltage across its winding.
[0052] In a sixteenth stage, the LC filter reduces the RMS value of both a
motor voltage and a motor current.
[0053] In an embodiment, a sensor-less IPMSM drive for PV-fed pump
configuration uses an LC filter. The reference DC link voltage signal from
the MPPT of the PV panel is compared with the actual DC link voltage. The
DC link voltage, the phase current, and the pole voltage are applied to the
sensor-less closed loop vector controller module. The sensor-less closed
loop vector controller module generates a pulsating voltage and provides
the pulsating voltage to the voltage source inverter. The voltage source
inverter converts the input DC link voltage to the AC phase voltage and the

AC phase current. The AC phase current and voltage are applied to the LC filter. The AC phase current and voltage are filtered using a 3-phase LC filter and the IPMS motor receives a sinusoidal voltage across its winding. The 3-phase sinusoidal voltage across the IPMS motor draws sinusoidal phase currents. The LC filter eliminates a major portion of harmonics and delivers sinusoidal voltage. The LC filter reduces the RMS value of both a motor voltage and a motor current. The reduced RMS value of the motor current reduces the winding copper losses and eliminates the high-frequency voltage harmonics. The lesser motor current reduces the winding copper losses as the harmonic copper losses are eliminated. Similarly, with the elimination of the high-frequency voltage harmonics, the core losses in the IPMS motor also reduce. The sensor-less closed loop vector controller module estimates the rotor position of the IPMSM drive with the output of the LC filter, which eliminates the requirement of an optical position encoder. The sensor-less closed loop vector controller module uses the MPPT, voltage source inverter, and the LC filter to improve the efficiency of the system.
[0054] It should be noted that the above advantages and other advantages will be better evident in the subsequent description. Further, in the subsequent section the present subject is better explained with reference to the figures.
[0055] Referring now to the drawings, particularly by their reference numbers, figure 1 illustrates a block diagram for sensor-less IPMS motor for PV fed pump 100. The sensor-less IPMS motor 100 includes a PV panel 102, a voltage source inverter 104, an LC filter 106, a sensor-less closed loop vector controller module 110, an IPMS motor 108 and a pump 112. The PV panel 102 is electrically connected to the voltage source inverter 104 and to the sensor-less closed loop vector controller module 110. The sensor-less closed loop vector controller module 110 takes input from the PV panel 102

and 3-phase current and pole voltage from the IPMS motor 108. The sensor-less closed loop vector controller module 110 provides pulsating output voltage signal to the voltage source inverter 104. The voltage source inverter 104 is electrically connected to the LC filter 106 and to the IPMS motor 108. The IPMS motor 108 is electrically connected to the pump 112. [0056] The sensor-less closed loop vector controller module 110 takes input from the PV panel 102 VDC and IDC and 3-phase current and pole voltage VAC and IAC from the IPMS motor 108, and provides pulsating output voltage signal SA, SB and SC to the voltage source inverter 104. [0057] Figure 2 illustrates a block diagram of a sensor-less closed loop vector controller module 200. The sensor-less closed loop vector controller module includes a MPPT 202, a torque controller 204, a MTPA 206, a subtraction unit 208, a current controller 210, a SVPWM 212, a co-ordinate transformer 1 216, a co-ordinate transformer 2 218 and a flux and position estimator 214. The sensor-less closed loop vector controller module 110 senses the DC voltage and DC current from the PV panel 102. The DC voltage (Vdc) and DC current (Idc) are extracted from the MPPT and generates the reference DC voltage (Vdc*). The torque controller 204 uses the DC voltage (Vdc) and the reference DC voltage (Vdc*) to estimate the reference stator current (Is*) at the desired rotation. The MTPA 206 is used to obtain the output as maximum torque under constant reference stator current (Id*) from the reference stator current (Is*). The 3-phase stator currents are transformed into the rotatory (d-q axes) current using the co¬ordinate transformer 2 218 and the stationary pole voltages are transformed into stationary (α-β) voltage (Vα, Vβ) using the co-ordinate transformer 1 216. The stationary (α-β) voltage and current are used to obtain the stator flux and angular position. The reference alpha-beta coordinate system Vα*, Vβ* are transformed and sent into the SVPWM 212. The SVPWM 212 adopts the space voltage vector pulse width modulation algorithm according to

stator voltage components Vα, Vβ to generate pulse width signal input to
the voltage source inverter.
[0058] Figure 3 illustrates a block diagram of a flux and position estimation
214 of a sensor-less IPMSM drive for PV fed pump, in accordance with an
embodiment of the present subject matter. The flux and position estimation
214 includes a flux estimator 302, a position estimator 304, a derivative unit
306 and a low pass filter 308. The αβ component of voltage and current
provides the stationary stator flux component (λα, λβ) and the stationary
stator current components (Iα, Iβ) using the flux estimator. The stationary
stator flux components (λα, λβ) and stationary stator current components
(Iα, Iβ) is used to estimate an angular position of the rotor θ and the
derivative unit along with the low pass filter 308 determines the angular
velocity of the rotor ω.
[0059] Figure 4 illustrates a flowchart of the sensor-less closed loop vector
controller module of the sensor-less IPMSM drive for PV fed pump
depicting an electric flow operation, in accordance with an embodiment of
the present subject matter.
[0060] In step 402, the sensor-less closed loop vector controller module 400
is activated.
[0061] In step 404, the sensor-less closed loop vector controller module
senses the DC voltage and DC current from the PV panel and the phase
current and pole voltage from the input of the IPMS motor and converts
analog phase current and pole voltage into digital.
[0062] In step 406, The DC voltage (Vdc) and DC current (Idc) extract the
maximum power using maximum power point tracking (MPPT) and
generate the reference DC voltage (Vdc*).
[0063] In step 408, the three-phase voltage and the three-phase current (VA,
VB, VC and IA, IB, IC) transforms the coordinate into a two-phase stationary
(α - β) voltage and current component.

[0064] In step 410, the two-phase stationary (α - β) voltage and current are used to calculate the stator flux αβ components, using the flux estimation unit.
[0065] In step 412, the stationary (α - β) stator flux and stationery (α - β) current component are used as input to the position estimation and the angular position θ is obtained. The angular position θ is used to obtain the angular velocity ώ and ω is obtained using the low pass filtering unit. [0066] In step 414, the actual DC voltage and the reference DC voltage are used to obtain the reference stator current (Is*) using first PI controller. [0067] In step 416, the maximum torque per ampere (herein referred to MTPA) uses the reference stator current (Is*) to obtain the output as maximum torque under constant reference stator current (Id*). [0068] In step 418, the d-q axes stator current is obtained from the actual stator current.
[0069] In step 420, the actual current component (Id, Iq) and the reference current component (Id*, Iq*) are used to calculate the reference dq-axis stator voltage (Vd*, Vq*) using second PI controller and third PI controller. [0070] In step 422, reference dq-axis stator voltage (Vd*, Vq*) are transformed into the (α-β) component using coordinate transformer. [0071] In step 424, the (α-β) component transforms into the pulsating voltage signal to drive the voltage source inverter using the SVPWM. [0072] Figure 5 illustrates a block diagram of current controller 210 of a sensor-less closed loop vector controller module in accordance with an embodiment of the present subject matter. The current controller 210 includes a second PI controller for the d-axis 502, a third PI controller 504 for the q-axis. The reference d-axis stator current (Id*) and the actual d-axis stator current (Id) determine the reference d-axis stator voltage (Vd*) using the second PI controller 502. The reference q-axis stator current (Iq*) and the

actual q-axis stator current (Iq) determine the reference q-axis stator voltage
(Vq*) using the third PI controller 504.
[0073] Figure 6 illustrates a block diagram of coordinate transformer 600 of
a sensor-less closed loop vector controller module (110) depicting the
pulsating voltage for the pulse width modulation. The coordinate
transformer 602 transforms the reference two phase rotatory stator voltage
(Vd*, Vq*) into the stationary stator voltage (Vα, Vβ). The stationary stator
voltage (Vα, Vβ) is realized at the required fixed switching frequency using
the SVPWM 212 and voltage source inverter 104.
[0074] Exemplary embodiments discussed above may provide certain
advantages. Though not required to practice aspects of the disclosure, these
following advantages may include.
[0075] Some embodiments of the sensor-less IPMSM drive for PV fed pump
with LC filter reduce the core losses and improve the efficiency of the IPMS
motor.
[0076] In some embodiments of the sensor-less IPMSM drive for PV fed
pump, the reduced RMS value of motor current reduces the winding copper
losses, and the reduced RMS value of motor voltage eliminates the high
frequency voltage harmonics.
[0077] Some embodiments of the sensor-less IPMSM drive for PV fed pump
reduce the total harmonic distortion in the IPMS motor voltage.
[0078] Although the description provides implementations of a sensor-less
IPMSM drive for PV fed pump, it is to be understood that the above
descriptions are not necessarily limited to the specific features or methods
of systems. Rather, the specific features and methods are disclosed as
examples of implementations for the sensor-less IPMSM drive for the PV
fed pump.

We claim:
1. A sensor-less internal permanent magnet synchronous (IPMS) motor
drive (100) for PV fed pump comprising:
a voltage source inverter (104), wherein the voltage source inverter (104) is electrically connected to a PV Panel (102), wherein the PV panel (102) is configured to provide DC voltage and DC current to the Voltage Source Inverter (104);
an LC filter (106), wherein the LC filter (106) is electrically connected to the voltage source inverter (104), a sensor-less closed loop vector controller module (110) and an IPMS motor (108), such that the LC filter (106) is placed at the output of the voltage source inverter (104) to receives currents for the voltage source inverter (104) and provides filtered phase output voltage and filtered phase output current to the sensor-less closed loop vector controller module (110) and to the IPMS motor (108), wherein the sensor-less closed loop vector controller module (110) is electrically connected to the LC filter (106), the PV panel (102) and the voltage source inverter (104) such that the sensor-less closed loop vector controller module (110) receives first input as filtered phase voltage and filtered phase current from the LC filter (106) and receives second input as DC voltage and DC current from the PV Panel (102) aid to estimate the angular position of rotor by estimating the plurality of stationary stator flux component (Act, Ap) and stationary stator current components (Ia, Ip) and provide output as pulsating voltage signal to the voltage source inverter (104);
2. The sensor-less IPMS motor drive (100) as claimed in claim 1, wherein
the sensor-less closed loop vector controller module (110) is
configured to provide the measured current component at its

reference value obtained from the actual DC voltage and reference DC voltage using a proportional-integral (PI) controller module.
3. The sensor-less IPMS motor drive (100) as claimed in claim 1, wherein the sensor-less closed loop vector controller module (110) is configured to provide the measured voltage components at the reference values (Vd*, Vq*) from the plurality of the actual current component (Id, Iq) and the reference current component (Id*, Iq*) using two proportional-integral (PI) controller modules.
4. The sensor-less IPMS motor drive (100) as claimed in claim 1, wherein sensor-less closed loop vector controller module (110) is configured to transform the rotating reference voltages (Vd*, Vq*) to the stationary voltages (Vα, Vβ) using coordinate transformer (216).
5. The sensor-less IPMS motor drive (100) as claimed in claim 1, wherein sensor-less closed loop vector controller module (110) is configured to provide input switching control of voltage signals to the voltage source inverter (104) using the space vector pulse width modulation (SVPWM) (212).