TECHNICAL FIELD
The present disclosure generally relates to a cooling arrangement and, in particular, relates
to a method and a system for controlling the cooling of multiple superconducting pole coils
of high temperature superconducting (HTS) synchronous machine
BACKGROUND
Background description includes information that may be useful in understanding the
present subject matter. It is not an admission that any of the information provided herein is
prior art or relevant to the presently claimed subject matter, or that any publication
specifically or implicitly referenced is prior art.
A typical high temperature superconducting (HTS) synchronous machine with multi-pole
superconducting rotor has even numbered superconducting pole coils in the rotor. These
superconducting pole coils are used to create electromagnetic field inside the machine.
These superconducting pole coils are cooled to operating cryogenic temperatures with the
help of a cryocooler. If cryogen used is in the gas form, the cooling circuit becomes a
convective heat transfer type of cooling system and the superconductive pole coils are
cooled with the help of gaseous cryogen.
The Superconducting synchronous machines such as motors and generators must be cooled
such that the field structures of their rotors are in the superconducting state. The
conventional approach to cooling rotor field coils is to immerse the rotor in a cryogenic
liquid. For example, a rotor employing field coils made of high temperature superconducting
materials might be immersed in liquid nitrogen. In this case, heat generated by or conducted
into the rotor is absorbed by the cryogenic liquid which undergoes a phase change to the
gaseous state. Consequently, the cryogenic liquid must be replenished on a continuing basis.

A cryocooler is used for maintaining operating cryogenic temperatures in HTS synchronous
machines. The cryocooling operation is carried out in a closed loop process. In this process,
cold cryogen is transferred from cryocooler to HTS rotor, while warm cryogen is collected
from HTS rotor and supplied back to cryocooler.
In some cases of in HTS cooling circuit, the cold and warm cryogen must be contained in
the piping and manifolds. These piping and manifolds along with support structure of
superconducting pole coils must be designed in order not to augment the physical
dimensions of rotating cryostat, especially to have minimum dynamic and steady-state heat
loads on cryocooler Since all piping and manifolds assembly are under vacuum, this
assembly must not add gaseous molecules through degassing to vacuum and should not
deteriorate the vacuum of the HTS rotor.
Thus, there remains a need for method and system for cryogenic cooling of a multiple
superconducting pole coils of high temperature superconducting (HTS) synchronous
machine with a non-magnetic material. Also, there is need for system and method for
cooling the multiple superconducting pole coils using gaseous cryogen in a circular
arrangement.
OBJECTS OF THE INVENTION
In view of the foregoing limitations inherent in the state of the art, some of the objects of
the present disclosure, which at least one embodiment herein satisfy, are listed herein below.
It is an object of the present disclosure to propose a cooling circuit arrangement for multiple
superconducting pole coils of high temperature superconducting (HTS) synchronous
machine.
It is another object of the present disclosure to propose a cooling circuit arrangement for
multiple superconducting pole coils of high temperature superconducting (HTS)

synchronous machine with a non-magnetic material such that an electromagnetic field
profile of machine is maintained even at cryogenic temperatures
It is yet another object of the present disclosure to propose a cooling circuit arrangement to
cool a plurality of superconducting pole coils of high temperature superconducting (HTS)
synchronous machine without augment additional physical dimensions to HTS rotor and
keeps it well within the active electromagnetic length of HTS synchronous machine
It is still yet another object of the present disclosure to propose a cooling circuit arrangement
with optimum thermal mass along with mechanical strength even at cryogenic temperatures.
It is a further object of the present disclosure to propose a cooling circuit arrangement and
fabricate the cooling circuit arrangement with minimum allowable ovality and eccentricity.
It is is still yet another object of the present disclosure to develop a cooling circuit
arrangement with materials having inherently low degassing characteristic under high
vacuum of the order of 10-6 mbar.
It is a further object of the present disclosure to assemble a cooling circuit arrangement with
multiple numbers of superconducting pole coils along with electrical and instrumentation
connections without electrical shortage and the complete assembly offer high insulation
resistance.
These and other objects and advantages of the present invention will be apparent to those
skilled in the art after a consideration of the following detailed description taken in
conjunction with the accompanying drawings in which a preferred form of the present
invention is illustrated.
SUMMARY OF THE INVENTION
This summary is provided to introduce concepts related to a method and a system for cooling
high temperature superconducting synchronous machine. The concepts are further described
below in the detailed description. This summary is not intended to identify key features or

essential features of the claimed subject matter, nor is it intended to be used to limit the
scope of the claimed subject matter.
The present disclosure relates to a cooling circuit arrangement of a high temperature
superconducting (HTS) synchronous machine comprises a multiple rotor having a plurality
of superconducting pole coils which is housed by a rotating cryostat and a cryocooler to
maintain a temperature of the superconducting pole coils A cryogen flow circuit having a
separate inlet cold cryogen pipe to enable inlet of a cold cryogen into the plurality of
superconducting pole coils wherein an outlet warm cryogen pipe enable outlet of a warm
cryogen out of the plurality of superconducting pole coils The cold cryogen secondary
manifold coupled to receive the cold cryogen from the inlet cold cryogen pipe and
distributed uniformly throughout a cold cryogen primary manifold The cold cryogen
primary manifold transfer the cold cryogen to the plurality of superconducting pole coils
and the cold cryogen gets warm and collected in a warm cryogen primary manifold and a
warm cryogen secondary manifold coupled to uniformly receive the warm cryogen and
characterized to transfer the warm cryogen to a cryocooler through cryogen transfer
coupling to achieve cryogenic cooling.
In an aspect, the cooling circuit arrangement are assembled with minimum allowable
ovality, eccentricity and support an electrical and instrumentation connections.
In an aspect, the cooling circuit arrangement of a high temperature superconducting (HTS)
synchronous machine is made of non-magnetic material.
The present disclosure relates to a method of cooling a high temperature superconducting
(HTS) synchronous machine having a multiple rotor comprising a plurality of
superconducting pole coils is disclosed. The method comprising the following steps, Step
1: Housing a multiple rotor having a plurality of superconducting pole coils by a rotating

cryostat and maintaining a temperature of the superconducting pole coils using a cyrocooler
Step 2: Providing a cryogen flow circuit with a separate inlet cold cryogen pipe to enable
inlet of a cold cryogen into the plurality of superconducting pole coils wherein enabling an
outlet warm cryogen pipe to transfer a warm cryogen out of the plurality of superconducting
pole coils. Step 3: Coupling a cold cryogen secondary manifold to receive the cold cryogen
from the inlet cold cryogen pipe and distributing uniformly throughout a cold cryogen
primary manifold. Step 4: Transferring said cold cryogen primary manifold the cold cryogen
to the plurality of superconducting pole coils and warming the cold cryogen and collecting
in a warm cryogen primary manifold Step 5: Coupling a warm cryogen secondary manifold
to uniformly receive the warm cryogen and transferring the warm cryogen to a cryocooler
through cryogen transfer coupling for achieving cryogenic cooling.
Other objects, features and advantages of the present disclosure will become apparent from
the following detailed description It should be understood, however, that the detailed
description and the specific examples, while indicating specific embodiments of the
invention, are given by way of illustration only, since various changes and modifications
within the spirit and scope of the invention will become apparent to those skilled in the art
from this detailed description.
BRIEF DESCRIPTION OF DRAWINGS
While the specification concludes with claims particularly pointing out and distinctly
claiming the subject matter that is regarded as forming the present subject matter, it is
believed that the present disclosure will be better understood from the following description
taken in conjunction with the accompanying drawings, where like reference numerals
designate like structural and other elements, in which:

FIG. 1 shows a longitudinal cross section of a HTS synchronous machine in an embodiment
of the present invention;
FIG. 2 shows a longitudinal cross section of a cooling circuit arrangement of HTS
synchronous machine in an embodiment of the present invention;
FIG. 3 shows a cross sectional view of a non-drive end primary cryogen manifold of cooling
circuit of rotating cryostat of HTS rotor, in accordance with an embodiment of the present
disclosure; and
FIG. 4 shows a cross sectional view of a drive end primary cryogen manifold of cooling
circuit of rotating cryostat of HTS rotor; in an accordance with an embodiment of the present
disclosure.
Numerals detail:
101-Rotating Cryostat Outer Shell
102-Rotating Cryostat enveloping superconducting pole coils
103-Stator Frame
104-Stator Non-Superconducting Coils
105-Drive End (DE) Shaft
106-Non-Drive End (NDE) Shaft
107-Inlet Cold Cryogen Pipe
108-Outlet Warm Cryogen Pipe
200 – Cooling circuit arrangement
201-Rotating Cryostat Envelope
202-Superconducting pole coil support
203- Superconducting pole coil of multipole rotor
204- Superconducting pole coil of multipole rotor
205-Inlet Cold Cryogen Pipe

206-Outlet Warm Cryogen Pipe
207-Cold Cryogen Primary Manifold
208-Cold Cryogen Secondary Manifold
209-Warm Cryogen Primary Manifold
210-Warm cryogen Secondary Manifold
301-NDE Cold Cryogen Primary Manifold
302-NDE Cold Cryogen Secondary Manifold
303-NDE Cold Cryogen Manifold Exits
304-Electrical and Instrumentation bush-1
305-Electrical and Instrumentation bush-2
306-Primary Cold Manifold to Superconducting pole coil Pipe for each Pole Coil of a
Multipole Rotor
401-Drive end warm cryogen primary manifold
402-Drive end warm cryogen secondary manifold
403-Drive end warm cryogen manifold entry
404-Primary warm manifold to superconducting pole coil pipe for each pole coil of a
multipole rotor.
DETAILED DESCRIPTION
The detailed description of various exemplary embodiments of the disclosure is described
herein with reference to the accompanying drawings It should be noted that the
embodiments are described herein in such details as to clearly communicate the disclosure

However, the amount of details provided herein is not intended to limit the anticipated
variations of embodiments; on the contrary, the intention is to cover all modifications,
equivalents, and alternatives falling within the spirit and scope of the present disclosure as
defined by the appended claims
It is also to be understood that various arrangements may be devised that, although not
explicitly described or shown herein, embody the principles of the present disclosure
Moreover, all statements herein reciting principles, aspects, and embodiments of the present
disclosure, as well as specific examples, are intended to encompass equivalents thereof
The terminology used herein is for the purpose of describing particular embodiments only
and is not intended to be limiting of example embodiments As used herein, the singular
forms “a”, “an”, and “the” are intended to include the plural forms as well, unless the context
clearly indicates otherwise It will be further understood that the terms “comprises”,
“comprising”, “includes”, “consisting” and/or “including” when used herein, specify the
presence of stated features, integers, steps, operations, elements and/or components, but do
not preclude the presence or addition of one or more other features, integers, steps,
operations, elements, components and/or groups thereof.
It should also be noted that in some alternative implementations, the functions/acts noted
may occur out of the order noted in the figures For example, two figures shown in
succession may, in fact, be executed concurrently or may sometimes be executed in the
reverse order, depending upon the functionality/acts involved.
Unless otherwise defined, all terms (including technical and scientific terms) used herein
have the same meaning as commonly understood by one of ordinary skill in the art to which
example embodiments belong It will be further understood that terms, e.g., those defined
in commonly used dictionaries, should be interpreted as having a meaning that is consistent
with their meaning in the context of the relevant art and will not be interpreted in an idealized
or overly formal sense unless expressly so defined herein

Embodiments explained herein pertain to arrangement of cooling circuit for a HTS
synchronous machine. FIG. 1 shows a longitudinal cross section of a HTS synchronous
machine 100 in an embodiment of the present invention The HTS synchronous machine
100 comprises a rotor and a stator. A rotating cryostat having a plurality of superconducting
pole coils 102 and an outer shell 101 to contain all cryogenic assemblies under vacuum The
stator has a stator frame 103 and houses stator non-superconducting pole coil 104 made up
of copper based air-gap winding coils The rotating cryostat is connected to Drive End (DE)
Shaft 105 and Non-drive end (NDE) shaft 106 at both ends through a suitable media. The
inlet cold cryogen pipe 107 and an outlet warm cryogen pipe 108 are enabling entities of
cryocooling closed-loop based circuit.
As can be appreciated by those skilled in the art, a cryogenically cooled surface circulating
a heat transfer fluid between the inlet cold cryogen pipe 107 and the outlet warm cryogen
pipe 108.
To limit the rise of the heat above a certain specified limit, different means and methods of
cooling, say, the superconducting pole coil 102 each having a corresponding cryogenically
cooled surface may be used to provide a level of redundancy, thereby allowing continued
operation of the system in the event that of repair or maintenance In such embodiments, the
inlet cold cryogen pipe 107 and the outlet warm cryogen pipe 108 may be provided to
selectively isolate at least one of the plurality of the superconducting pole coils 102 from
remaining ones of the plurality of superconducting pole coils 102.
FIG. 2 shows a longitudinal cross section of a cooling circuit arrangement 200 of HTS
synchronous machine 100 in an embodiment of the present invention The cooling circuit
arrangement 200 of HTS synchronous machine configured to have a rotating cryostat
envelope 201 that houses a plurality of superconducting pole coils 203, 204 and a
superconducting coil support 202 The rotating cryostat has an inlet cold cryogen pipe 205

to enable inlet of cold cryogen into the plurality of superconducting pole coils 203, 204,
while outlet warm cryogen pipe 206 enable outlet of warm cryogen out of the plurality of
superconducting pole coils 203, 204 A closed loop is formed through various manifolds
and a cryogen transfer assembly The inlet cold cryogen comes initially in a cold cryogen
secondary manifold 208 and gets distributed uniformly to a cold cryogen primary manifold
207 From the cold cryogen primary manifold 207, the cold cryogen is transferred to the
plurality of superconducting pole coils 203, 204 to achieve cryogenic cooling This way
cold cryogen gets warmed up and collected in a warm cryogen primary manifold 209 This
is uniformly received by a warm cryogen secondary manifold 210 and transfer the warm
cryogen to a cryocooler through cryogen transfer coupling to achieve cryogenic cooling. I a
preferred embodiment the warm cryogen is passed to the cryogen transfer assembly The
cooling closed loop circuit is without any additional augment physical dimensions to HTS
rotor and keeps it within the active electromagnetic length of the HTS synchronous machine
100. In a preferred embodiment an overall length and volume of HTS synchronous machine
100 could be brought down considerably using this cooling circuit arrangement 200
FIG. 3 shows a cross sectional view of a non-drive end primary cryogen manifold of cooling
circuit 300 of rotating cryostat of HTS rotor, in accordance with an embodiment of the
present disclosure A non-drive end primary cryogen manifold of cooling circuit of rotating
cryostat of HTS rotor comprising a cold cryogen primary manifold 301 and a cold cryogen
secondary manifold 302 The inlet cold cryogen comes initially to the cold cryogen
secondary manifold 302 and gets distributed uniformly to the cold cryogen primary
manifold 301 through various exits 303 For example the various exist could be manifold or
pipes. The cold cryogen from the cold cryogen primary manifold 301 is then transferred to
a plurality of pipes of each superconducting coil 306 of a multipole rotor The cold cryogen

primary manifold 301 also gives support to electrical and instrumentation bushes 304, 305
for routing the cold cryogen inside the rotating cryostat.
FIG. 4 shows a cross sectional view of a drive end primary cryogen manifold of cooling
circuit 400 of rotating cryostat of HTS rotor, in an accordance with an embodiment of the
present disclosure A drive end primary cryogen manifold of cooling circuit of rotating
cryostat of HTS rotor comprises a warm cryogen primary manifold 401 and a warm cryogen
secondary manifold 402. The outlet warm cryogen comes from a plurality of pipes of each
superconducting coil 404 of a multipole rotor to the warm cryogen primary manifold 401
and gets distributed uniformly to the warm cryogen secondary manifold 402 through various
collection pipes 403
In one embodiment the cold cryogen primary manifold 207 and the cold cryogen secondary
manifold 208 are thermally isolated from each other and distribute the cold and warm
cryogen, into the multiple rotor, for cooling the superconducting pole coils 203, 204.
In one embodiment the cooling circuit arrangement 200 cools the plurality of
superconducting pole coils 203,204 of high temperature superconducting (HTS)
synchronous machine 100 and keeps it well within the active electromagnetic length of HTS
synchronous machine. Also, maintains the optimum thermal mass along with mechanical
strength even at cryogenic temperatures In a preferred embodiment the electrical and
instrumentation connections are maintained without electrical shortage and the complete
assembly offers high insulation resistance.
In one embodiment the high temperature superconducting (HTS) synchronous machine
(100) provided with a cooling circuit arrangement 200 comprises the multiple rotor having
a plurality of superconducting pole coils 203, 204 which is housed by a rotating cryostat and
a cryocooler to maintain a temperature of the superconducting pole coils (203, 204) A

cryogen flow circuit having a separate inlet cold cryogen pipe (205) to enable inlet of a cold
cryogen into the plurality of superconducting pole coils (203, 204), wherein an outlet warm
cryogen pipe (206) enable outlet of a warm cryogen out of the plurality of superconducting
pole coils (203, 204) The cold cryogen secondary manifold 208 coupled to receive the cold
cryogen from the inlet cold cryogen pipe 205 and distributed uniformly throughout a cold
cryogen primary manifold 207 The cold cryogen primary manifold 207 transfer the cold
cryogen to the plurality of superconducting pole coils 203, 204 and the cold cryogen gets
warm and collected in a warm cryogen primary manifold 209 and a warm cryogen secondary
manifold 210 coupled to uniformly receive the warm cryogen and characterized to transfer
the warm cryogen to a cryocooler through cryogen transfer coupling to achieve cryogenic
cooling.
In one embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, wherein the plurality of superconducting
pole coils 203, 204 are cooled by the cold cryogen supplied by the cold cryogen primary
manifold 207 and the warm cryogen is collected in the warm cryogen primary manifold 209
In a preferred embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, wherein the cold cryogen primary
manifold 207 configured to receive the cold cryogen from the cold cryogen secondary
manifold 208 and characterized to uniformly distribute to the plurality of superconducting
pole coils 203, 204 and the warm cryogen primary manifold 209 receives the warm cryogen
from the plurality of superconducting pole coils 203, 204 and transfer to the warm cryogen
secondary manifold 208 which transfer the warm cryogen to the cryogen transfer assembly.
In one embodiment the method and system for cooling high temperature superconducting
(HTS) synchronous machine (100) having multi-pole rotor which comprises a plurality of
superconducting pole coils (203, 204) using a cooling circuit arrangement (200) The

plurality of superconducting pole coils (203, 204) are cooled to operating cryogenic
temperatures and maintained at those temperatures with the help of a cryocooler. The
cooling circuit arrangement comprises a cryogen cooling circuit having a separate inlet cold
cryogen pipe (107) and an outlet warm cryogen pipe (108) in the intended path to cool the
plurality of superconducting pole coils (203, 204) The cryogen cooling circuit is fabricated
out of suitable non-magnetic and high strength materials to operate at stringent magnetic
fields and cryogenic temperatures The superconducting pole coils (203, 204) of a multipole
rotor are placed in a chamber to have a circular arrangement Various primary and secondary
manifolds guide the cryogen to the superconducting pole coils (203, 204) and collect without
compromising mechanical integrity of the system and augmenting additional physical
dimensions.
In one embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, wherein the inlet cold cryogen pipe 107
and the outlet warm cryogen pipe 108 are enabling entities of cryocooling closed-loop
circuit.
In one embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, further comprises a non-drive end
primary cryogen manifold 300 and a drive end primary cryogen manifold 400
In a preferred embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, assembled with minimum allowable
ovality, eccentricity and support an electrical and instrumentation connections The
superconducting pole coils (203, 204) of the multipole rotor are positioned in a chamber of
circular arrangement for efficient cooling
In one embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, the cryogenic flow circuit made of non-

magnetic material such as stainless steel, titanium, or any preferred material. The cooling
circuit arrangement 200 of a high temperature superconducting (HTS) synchronous machine
100, maintain an original signature of electromagnetic field lines at cryogenic temperatures.
In a preferred embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, maintain high vacuum of the order of
10-6 mbar.
In one embodiment the cooling circuit arrangement 200 of a high temperature
superconducting (HTS) synchronous machine 100, shows no considerable change in
vacuum due to degassing of cooling structure. The cooling circuit arrangement 200 of a high
temperature superconducting (HTS) synchronous machine 100, maintains high insulation
resistance in the multiple rotor assembly
In one embodiment a method of cooling a high temperature superconducting (HTS)
synchronous machine 100 having a multiple rotor comprising a plurality of superconducting
pole coils 203, 204 is disclosed The method comprising the following steps, Step 1:
Housing a multiple rotor having a plurality of superconducting pole coils 203, 204 by a
rotating cryostat and maintaining a temperature of the superconducting pole coils 203, 204
using a cyrocooler Step 2: Providing a cryogen flow circuit with a separate inlet cold
cryogen pipe 205 to enable inlet of a cold cryogen into the plurality of superconducting
pole coils 203, 204, wherein enabling an outlet warm cryogen pipe 206 to transfer a warm
cryogen out of the plurality of superconducting pole coils 203, 204 Step 3: coupling a cold
cryogen secondary manifold 208 to receive the cold cryogen from the inlet cold cryogen
pipe 205 and distributing uniformly throughout a cold cryogen primary manifold 207 Step
4: transferring said cold cryogen primary manifold 207 the cold cryogen to the plurality of
superconducting pole coils 203, 204 and warming the cold cryogen and collecting in a warm
cryogen primary manifold 209 Step 5: Coupling a warm cryogen secondary manifold 210

to uniformly receive the warm cryogen and characterizing to transfer the warm cryogen to
a cryocooler through cryogen transfer coupling for achieving cryogenic cooling
Furthermore, each of the appended claims defines a separate invention, which for
infringement purposes is recognized as including equivalents to the various elements or
limitations specified in the claims. Depending on the context, all references below to the
“invention” may in some cases refer to certain specific embodiments only In other cases, it
will be recognized that references to the “invention” will refer to subject matter recited in
one or more, but not necessarily all, of the claims.
Groupings of alternative elements or embodiments of the invention disclosed herein are not
to be construed as limitations Each group member can be referred to and claimed
individually or in any combination with other members of the group or other elements found
herein. One or more members of a group can be included in, or deleted from, a group for
reasons of convenience and/or patentability When any such inclusion or deletion occurs,
the specification is herein deemed to contain the group as modified thus fulfilling the written
description of all groups used in the appended claims.
Furthermore, those skilled in the art can appreciate that the terminology used herein is for
the purpose of describing particular embodiments only and is not intended to be limiting of
the present disclosure It will be appreciated that several of the above-disclosed and other
features and functions, or alternatives thereof, may be combined into other systems or
applications Various presently unforeseen or unanticipated alternatives, modifications,
variations, or improvements therein may subsequently be made by those skilled in the art
without departing from the scope of the present disclosure as encompassed by the following
claims

The claims, as originally presented and as they may be amended, encompass variations,
alternatives, modifications, improvements, equivalents, and substantial equivalents of the
embodiments and teachings disclosed herein, including those that are presently unforeseen
or unappreciated, and that, for example, may arise from applicants/patentees and others.
While the foregoing describes various embodiments of the present disclosure, other and
further embodiments of the present disclosure may be devised without departing from the
basic scope thereof The scope of the present disclosure is determined by the claims that
follow The present disclosure is not limited to the described embodiments, versions or
examples, which are included to enable a person having ordinary skill in the art to make and
use the invention when combined with information and knowledge available to the person
having ordinary skill in the art

WE CLAIM:
1. A cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100), comprising:
a multiple pole rotor having a plurality of superconducting pole coils (203, 204)
which is housed by a rotating cryostat and a cryocooler to maintain a required temperature
of the superconducting pole coils (203, 204);
a cryogen flow circuit having a separate inlet cold cryogen pipe (205) to supply
cold cryogen gas into the plurality of superconducting pole coils (203, 204), wherein an
outlet warm cryogen pipe (206) enable outlet of a warm cryogen out of the plurality of
superconducting pole coils (203, 204);
a cold cryogen secondary manifold (208) coupled to receive the cold cryogen from
the inlet cold cryogen pipe (205) and distributed uniformly throughout a cold cryogen
primary manifold (207);
said cold cryogen primary manifold (207) transfer the cold cryogen to the plurality
of superconducting pole coils (203, 204) and the cold cryogen gets warm and collected in
a warm cryogen primary manifold (209) and
a warm cryogen secondary manifold (210) coupled to uniformly receive the warm
cryogen and characterized to transfer the warm cryogen to the cryocooler through a
cryogen transfer coupling to achieve cryogenic cooling.
2. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in claim 1, wherein the plurality of
superconducting pole coils (203, 204) are cooled by the cold cryogen supplied by the

cold cryogen primary manifold (207) and the warm cryogen is collected in the warm
cryogen primary manifold (209).
3. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in claim 1 OR 2, wherein the cold cryogen
primary manifold (207) configured to receive the cold cryogen from the cold cryogen
secondary manifold (208) and characterized to uniformly distribute to the plurality of
superconducting pole coils (203, 204) and the warm cryogen primary manifold (209)
receives the warm cryogen from the plurality of superconducting pole coils (203, 204)
and transfer to the warm cryogen secondary manifold (208) which transfer the warm
cryogen to the cryogen transfer assembly.
4. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein the inlet
cold cryogen pipe (107) and the outlet warm cryogen pipe (108) are enabling entities of
cryocooling closed-loop circuit.
5. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, further comprises
a non-drive end primary cryogen manifold (300) and a drive end primary cryogen
manifold (400).
6. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein the
cooling circuit arrangement (200) are assembled with minimum allowable ovality,
eccentricity and support an electrical and instrumentation connections.
7. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein cryogen
flow circuit is made of non-magnetic material.

8. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein the
cooling circuit arrangement (200) maintain an original signature of electromagnetic field
lines at cryogenic temperatures.
9. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein the
cooling circuit arrangement (200) maintain high vacuum of the order of 10-6 mbar
10. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein
degassing of cooling circuit structure does not substantially change the vacuum
11. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein cooling
circuit arrangement (200) maintains high insulation resistance in the multi-pole rotor
assembly
12. The cooling circuit arrangement (200) of a high temperature superconducting (HTS)
synchronous machine (100) as claimed in any of the preceding claims, wherein the
superconducting pole coils (203, 204) of the multipole rotor are positioned in a chamber
of circular arrangement for efficient cooling.
13. A method of cooling a high temperature superconducting (HTS) synchronous machine
(100) having a multi-pole rotor comprising a plurality of superconducting pole coils
(203, 204), said method comprising the steps of:
housing a multiple rotor having a plurality of superconducting pole coils (203, 204)
by a rotating cryostat and maintaining a temperature of the superconducting pole
coils (203, 204) using a cyrocooler;
configuring a cryogen flow circuit with a separate inlet cold cryogen pipe (205) to
enable inlet of a cold cryogen into the plurality of superconducting pole coils (203,

204), wherein enabling an outlet warm cryogen pipe (206) to transfer a warm
cryogen out of the plurality of superconducting pole coils (203, 204) comprises :-
coupling a cold cryogen secondary manifold (208) to receive the cold cryogen
from the inlet cold cryogen pipe (205) and distributing uniformly throughout a cold
cryogen primary manifold (207);
transferring the cold cryogen from the cold cryogen primary manifold (207) to the
plurality of superconducting pole coils (203, 204) and warming the cold cryogen
and collecting in a warm cryogen primary manifold (209) and
coupling a warm cryogen secondary manifold (210) to uniformly receive the warm
cryogen from the warm cryogen primary manifold (209) and transfer to a
cryocooler through cryogen transfer coupling for achieving cryogenic cooling