Evolution of High power AM transmitter technology

and

Comparison of type S7HP and TMW2100 transmitters

AM-DSB modulation in communication

AM is the least efficient mode of communication

Hence, the process of generation of high power AM-DSB signals needs to be highly efficient

Evolution of AM Transmitter technologyEvolution of AM Transmitter technology < 1970:< 1970: Class-C PA and Class-B modulator using triodes.

~~1970: Class-D PA and Class-B modulator using tetrodes.

~~1984: 1984: Dynamic carrier control for electrical energy saving.

~~1984:1984: PSM modulator using GTOs replaced Class-B modulator.

~~2000:2000: Modular design. MOSFET as high speed switching device and DSP to implement the switching algorithm. (Fall out of PSM Technology)

SOLID STATE MODULAR TRANSMITTERSSOLID STATE MODULAR TRANSMITTERS

TechnologyTechnology

Uses solid state, high speed switching devices for generating the RF output.

Due to limited power dissipation of the solid state devices, number of plug-in RF power amplifiers are used.

Switching (sampling) rate of the PA switching is function of instantaneousinstantaneous modulation of the carrier limited to Nyquist criteria.

Command for switching and control of each of the devices is generated by high speed DSP electronics.

BenefitsBenefits High conversion efficiency.

Modular design and hence redundancy in operation.

Low cost maintenance due to inexpensive expendable components.

Ease of operation in different modes viz AM-DSB, DCC, DRM.

Robust protection against faults and disturbances.

Excellent audio quality.

Connection topology of RF modules in series

DSPem

Ec

Connection topology of RF modules/lines in parallel

Connection topology of RF modules in series || parallel

Comparison of the topology

SERIAL PARALLEL MIXED

O P ER A T IO N

M O D UL E V O L T A G E AD D E DSA M E C UR R E NT

M O D UL E C UR R ENT AD D E DSA M E V O L T A G E

M O D UL E V O L T A G E ANDC UR R ENT

AD D E D A ND C O M B INE D

S T A B IL IT Y W IT H O NE O RM O R E M O D UL E O UT O F

O R D E R

ST A B L EP O W ER D E C R E A S ES

UNS T AB L EPO W E R R E M A INS C O NS T ANT

S T A B L E UND E R C O ND IT IO NSM A L L UNBA L A NC E D V O L T A G E

D IF F E R ENC E

D IS A B L E D M O D UL EM O D UL E F AUL T A L L O W ED

S HO R T -C IR C UITT HE NO R M A L T R A NS IST O R

F A IL UR E M O D E

O PE N C IR C UITNE E D A D D IT IO NA L

PR O T E C T IO N

S HO R T C IR C UIT L IM IT E DNUM B E R O F F A UL T Y M O D UL E

L IM IT E D

L IM IT A T IO N HIG H V O L T A G E L INE L E NG T HL O AD V A R IA T IO N

HIG H C UR R E NTL O W IM P E D A NC E

INC R EA S E D L O S S E S

VO L T A G E A NDC UR R E NT C O M B INED

T HO M C AS T S O L UT IO N1 2 0 T O 1 6 0 M O D UL E S

IN S ER IAL1 5 0 kW

NIL2 L INE S O F 1 2 8 M O D UL E S IN

SE R IA L4 0 0 kW

P HA S E VA R IA T IO N AL L O W E D F O R BID D EN AL L O W E D

Comparison of S7HP and TMW 2100

S UP E R VI S I O N ( S V)

F AS T S V BA S I C S V

S T AG EP O W ER S UP P LY

A

D

A

D

A U D I OI N P U T

M E AS UR I N G S P C O N T R O L

AUD I O I F BAS I C S P F AS T S P R F G EN ER AT O R P R E - D I S T R

C S M C T R L

M M I R E M O T E M M I EX T . C T R L

T X C T R L

SI GN A L P R O C E SSI N G ( SP )

L I N EP O W E R

C O O L I N GSY ST E M

R F ST A GE S

C T R LP O W ER S UP P LY

M 2 WT R AN S M I T T ER

O UT P UTF IL T E R

D I S T R I B C O M BI N ER

P O W ER AM P L I F E R

C O O L IN G AI R

tit le :1 0 0 KW - M W M O D UL AR * M 2 W * T X - C O N T R O L

Schematic of PA used in TMW 2100

Timing diagram of the control signals fc+ and fc- in PA module of TMW 2100

5 kW Power pack of TMW2100

B L O C K S C H E M A T I C O F 3 0 0 K W T R A N S M I T T E R

T r. T r.

11K V/ 41 5V750K VA

T R F -2

11K V

P O W ERT R A N S F O R M ER

P A#17M A N A GEM EN T

A N DC O N T R O L

E N C O D E RA M P L I F I E R

C I R C U I T

B L O C KM M I E X C I T E R

R EM O T E M M I

R EM O T ED IS T R IB U T IO N C IR C U IT

LEF T LIN E

A D A P T A T IO N U N IT

P A # 1

H Y D R A U L ICS Y S T E M

R EC T IF IER

M A INR EC T IF IER

A U X IL IA R YR E C T IF IE R

M A L T A N DL O C K I N GSY ST E M

R F F ILT ER

R F C H A N G E O V E RS W IT C H

D U M M Y LO A D

M A T C H IN GU N IT

50 K WM W

V E N T I L A T O R# 2

V E N T I L A T O R# 1

900K VA A VR

125 K VAD G S ET

P O W ER S U P P LYEN C LO S U R E

A M P LIF IER B LO C K

P ILO T -1 P ILO T -2S ELEC T IO N B O A R D

R FC M D S

R FS IGN A L

B LO C KIN T ER N A L P O W ER S U P P LIES

VLVP O W ER

S U P P LIES

410 V

LV IN P U T

ELC T R O T EC H N IC A L R A C K

F A U LTC O M M A N D

H Y D R A U L I C SY ST E MV E N T I L A T I O N SY ST E M VEN T ILA T O R

EX H A U S T

R F S IGN A LLEF T T H E

R F S IGN A LR IGH T LIN E

A M P L IF IE R M O D U L E S A S S E M B L IE S

-Vin t

330V 330V

33 0V

LV

INP

UT

TO

ELE

CT

RO

TE

CHN

ICA

L R

AC

K

R FT R A N S F O R M ER

120 0A

LVG

PS

EXTE

RNA

L

P A # 16 P A # 3 2

T R F -180 0A

800A50K W LT R O O M

T x HALLHEAT IN G

1200

A

630A

1600

A

1200

A

100A

SPA

RE

AUD

IO R

ACK

HYD

RAU

LIC

S

DUM

MY

LOA

D

VEN

TIL

ATO

R

F RO M O UT S ID E

F R O M E T

R A C K

Schematic of PA used in S7HP

PA of PA of S7 HPS7 HP

Similarities in Similarities in S7HPS7HP and and TMW 2100TMW 2100 The technology is similar.

PAs use IRFP460LC MOSFETs as high speed Switching devices in a H-bridge configuration.

Uses DSP processors for implementing the algorithms for module switching, thermal balancing, rotation etc.

Uses PWM/phase modulation to get fine envelope and digital modulation.

Control through MMI, remote terminal etc.

Built in DCC and DRM ready

No hot plugging of PA modules.

Boards are not inter-changeable.Boards are not inter-changeable.

Differences in S7HP and TMW 2100

PA topologyPA topology Series – parallelSeries – parallel SeriesSeries

Fine controlFine control 7 Dedicated PAs7 Dedicated PAs All PAsAll PAs

TechnologyTechnologyMPM-PMPM-P33

[MMultiple pparameter mmodulator with ppulse

pprecision pphase]

MM22W W [MModular MMedium wwave]

Power build upPower build up 248 CSM controlled PAsAll 80 PAs are

CSM/PWM/phase controlled

Power output of each PAPower output of each PA 2.34 kW 1.25 kW

AvailabilityAvailability Blocks of 400 kWBlocks of 400 kW 10 kW to 125 kW10 kW to 125 kW

Differences in S7HP and TMW 2100

PA Module monitoringPA Module monitoring Through fuse status

Through fuse status, correlation check between I/P - O/P signals, VDD and

Temperature

Signal distributionSignal distributionThrough distribution board one each for 16

modules

Through distribution board one for block of

each 4 modules

Supervision of Supervision of defective PAsdefective PAs

By multiplexing the feedback from each PA

Defective PA is switched OFF at power pack level and status indicated to Control System.

Differences in S7HP and TMW 2100

WorksWorks Conflans, France Turgi, Switzerland

Defective modules Defective modules in circuitin circuit

Output clips shorts Dummy module to be inserted

Gate driveGate driveDirectly driven through VINT PS

Through a chopper AC/DC power supply

CoolingCooling Water and air Air

Thank you