IRPT2051C - International Rectifier

page 1

IRPT205

Revised 5/97

PD 6.073C

™

Integrated Power Stage for 3 hp Motor Drives

IRPT2051

PRELIMINARY

·3 hp (2.2kW) motor drive

Industrial rating at 150% overload for 1 minute

·380 - 480V AC, 50/60Hz

·Available as complete system or sub-system assemblies

Power Module

·3-phase rectifier bridge

·3-phase, short circuit rated, ultrafast IGBT inverter

·Brake IGBT and diode

·Low inductance (current sense) shunts in positive and

negative DC rail

·NTC temperature sensor

·Pin-to-base plate isolation 2500V rms

·Easy-to-mount two-screw package

·Case temp. range -25° deg C to 125 deg C operational

Driver-

Plus

Board

·DC bus capacitor filter with NTC inrush current limiter

·IR2233 monolithic 3-phase HVIC driver

·Driver stage for brake transistor

·On-board +15V and +5V power supply

·MOV surge suppression at input

·DC bus voltage and current feedback

·Protection for short-circuit, earth/ground fault,

overtemperature and overvoltage

·Terminal blocks for 3-phase input/output and brake

connections

Figure 1. The IRPT2051C within a motor

control system

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IRPT2051

System Description

The IRPT2051C provides the complete

power conversion function for a 3hp (2.2kW) variable-frequency,

variable-voltage, AC motor controller. The

combines a power assembly IRPT2051A with a Driver-Plus

Board IRPT2051D. Figure 1 shows the block diagram of the

within an AC motor control system.

The power module contains a 3-phase input bridge rectifier, 3-

phase IGBT and diode, 3-phase IGBT inverter, current sense

shunts, and a thermistor. It is designed for easy mounting to a

heat sink.

The Driver-Plus Board contains DC link capacitors, capacitor

soft charge function using NTC thermistor, surge suppression

MOVs, IGBT gate drivers, DC bus voltage and current feedback

signals, protection circuitry and local power supply. It is de-

signed to mate with a controller board through a single row

header. Terminal blocks are also provided on the Driver-Plus

Board for all end-user line input, motor output, and brake resis-

tor.

Output power is Pulse-Width Modulated (PWM), 3-phase,

variable-frequency, variable voltage controlled by an externally-

generated user-provided PWM controller for inverter IGBT

switching. The power supply offers the user non-isolated 5V and

15V to power the microcontroller.

The IRPT2051C offers several benefits to the drive manufac-

turer as listed below:

•It eliminates component selection, design layout, intercon-

nection, gate drive, local power supply, thermal sensing,

current sensing, and protection.

•Gate drive and protection circuits are designed to closely

match the operating characteristics of the power semicon-

ductors. This allows power losses to be minimized and

power rating to be maximized to a greater extent than is

possible by designing with individual components.

•It reduces the effort of calculating and evaluating power

semiconductor losses and junction temperature.

•It reduces the manufacturer's part inventory and simplifies

assembly.

[ specifications and ratings are given for

system input and output voltage and current, power losses

and heat sink requirements over a range of operating con-

ditions. system ratings are verified by IR

in final testing.]

The IRPT2051A Power Module

The IRPT2051A power module, shown in figure 2, is a chip

and wire epoxy-encapsulated module. It houses input rectifiers,

brake IGBT and freewheeling diode, output inverter, current

sense shunts and NTC thermistor. The 3-phase input bridge

rectifiers are rated at 1600V. The brake circuit uses 1200V

IGBT and free-wheeling diode. The inverter section employs

1200V, short circuit rates, ultrafast IGBTs and ultrafast free-

wheeling diodes. Current sensing is achieved through 25 mΩΩΩΩΩ

low-inductance shunts provided in the positive and negative

DC bus rail. The NTC thermistor provides temperature sensing

capability. The lead spacing on the power modulemeets UL840

pollution level 3 requirements.

Figure 2. IRPT2051A Power Module

The power circuit and layout within the module are carefully

designed to minimize inductance in the power path, to reduce

noise during inverter operation and to improve the inverter effi-

ciency. The Driver-Plus Board required to run the inverter can

be soldered to the power module pins, thus minimizing assembly

and alignment. The power module is designed to be mounted to

a heat sink with two screw mount positions, in order to insure

good thermal contact between the module substrate and the heat

sink.

page 3

IRPT2051

The IRPT2051D Driver-

Plus

Board

The Driver-Plus Board, shown in figure 3, is the interface be-

tween the controller and the power stage. It contains the IGBT

gate drivers, protection circuitry, feedback, brake drive and local

power supply. The driver also interfaces to the AC input line. It

houses the DC link capacitors, NTC in-rush limiting thermistor,

and surge suppression MOVs.

The inverter gate drive circuits, implemented with an

IR2233 monolithic 3-phase HVIC driver, deliverrs gate drive to

the IGBTs corresponding to PWM control signals IN1 through

IN6. it introduces a 0.2 µsec dead time between upper and lower

gate signals for each phase. Any additional dead time necessary

tmust be included in the PWM signals. After a fault condition

all inverter gate drivers are disabled and latched. The FAULT

pin is also pulled low through an open drain which illuminates a

red LED. Gate drives must be enabled with an active low pulse

applied to the RESET pin while PWM inputs In1,...IN6 are held

high (off condition). The FAULT condition can also be set by

the controller through an active high signal on the STOP pin.

After power-up, the RESET pin must be pulled low before any

input signals are activated.

The protection circuitry will set a FAULT for short-circuit,

earth-fault, over-temperature, or over-voltage conditions as

specified. Current signals are sensed through shunts in positive

and negative DC bus rails. Earth faults are sensed using the

high-side shunt and the signal is fed through an opto-isolator to

the protection circuitry. Over-voltage is sensed through a resis-

tor divider from the positive DC bus. Over-temperature

protection is obtained using a thermistor inside the power mod-

ule. A FAULT condition occurs inf the temperature of the

power module's IMS substrate exceeds the trip level. The sys-

tem is designed for 150% overload for one minute while

operating with the specified heat sinks. The controller should

shut off the PWM signals if the overload persists for more than

one minute.

The feedback signals used by the protection circuitry are also

available to the controller. The current feedback signal from the

low-side shunt is available on the IFB pin at 0.025 V/A. If filter-

ing of this signal is required, it should be done by adding a

high-impedance buffer stage between signal and filter. The DC

bus reference is provided on VFB. This reference has been

scaled down by a factor of 100 and should also be protected with

a high-impedance buffer stage.

The brake function is implemented by connecting a power

resistor between the terminals on the Brake terminal block. The

value and power of theresistor determines maximum braking ca-

pability along with the rating of the brake IGBT. The input

signal on IN7 is active low and CMOS or LSTTL compatible.

The switching power supply employs an IR2152 self-oscil-

lating driver chip in a buck regulator topology to deliver a

nominal 15V and 5V DC with respect to the negative bus (N).

The power supply feeds the gate drive and protection circuits.

The 15V (VCC) and 5V (VDD) outputs are available on the con-

trol interface for powering the user's control logic.

Figure 3. IRPT2051D Driver-

Plus

Board

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IRPT2051

Figure 4. IRPT2051C Basic Architecture

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IRPT2051

PARAMETERS VALUES CONDITIONS

Input Power

Voltage 380V, -15%, 480V +10%

Frequency 50 - 60Hz

Input current 8.26A rms @ nominal output TA = 40°C, RthSA = 0.59°C/W

125 A peak Initial bus capacitor charging

Output Power

Voltage 0 - 480V rms defined by external PWM control

Nominal motor hp (kW) 3hp (2.2 kW) nominal full load power RthSA = 0.59°C/W,

150% overload for 1 minute Vin =460V AC, fPWM = 4kHz,

Nominal motor current 5.90A rms nominal full load current f°=60Hz, TA = 40°C,

8.85A rms 150% overload for 1 minute ZthSA limits ÐTc to 10°C during overload

Control Inputs

IN1...IN6, (PWM), IN7 (Brake), 5V maximum, active low CMOS, LSTTL compatible,

RESET open collector

STOP 5V maximum, active high CMOS or LSTTL compatible

Pulse deadtime 0.2

sec typical, set by IR2233 maximum set by controller

Minimum input pulse width 1.0

sec

Protection

Output current trip level 45A peak, ±10% TC = 25°C

Earth fault current trip level 50A, ±10% TC = 25°C

Overtemperature trip level 100°C, ±5% Case temperature

Overvoltage trip level 850V, ±10%

Maximum DC link voltage 760V user to ensure rating not exceeded >30 sec

Short circuit shutdown time 2.5

sec typical output terminals shorted

Feedback Signals

Current feedback (IFB) 0.025V/ABUS typical TC = 25°C

DC bus voltage feedback (VFB) 0.010V/VBUS typical TC = 25°C

Fault feedback (FAULT) 5V maximum, active low CMOS or LSTTL compatible

On Board Power Supply

VCC 15V, ±10%

VDD 5V, ±5%

ICC + IDD 60 mA available to user

Brake

Current 10.5A

Module

Isolation voltage 2500V rms pin-to-baseplate isolation, 60Hz, 1 min.

Operating case temperature -25°C to 125°C 95% RH max. (non-condensing)

Mounting torque 1 N-m M4 screw type

System Environment

Ambient operating temp. range 0 to 40°C 95% RH max. (non-condensing)

Storage temp.range -25 to 60°C

Specifications

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IRPT2051

Operating Conditions: Vin = 460Vrms MI=1.15, PF-0.8, TA=40°C, ZthSA limits temperature rise (ÐTc) during 1 minute overload to 10°C

Figure 5b. 5hp/8.25A output Heat Sink Thermal Resistance and Power Dissipation vs. PWM Frequency

(Induction Motor Load)

Figure 5a. 7.5hp/12.5A output Heat Sink Thermal Resistance and Power Dissipation vs. PWM Frequency

(Induction Motor Load)

0.2

0.4

0.6

0.8

1.2

1.4

1 4 8 12 16 20 24 0

100

120

140

160

180

200

Power

100%

Power

150%

RthSA 150% Load (1 min.)

10-60 Hz

RthSA100% Load Continuous

10-60 Hz

PWM Frequency (kHz)

Thermal Resistance (RthSA

¡C/W)

Total Power Dissipation (Watts)

RthSA150% Load (1 min.)

Down to 3 Hz

2hp

(1.5 kW)

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

14812

16 20 24 0

100

150

200

250

300

Power

100%

Power

150%

RthSA 150% Load (1 min.)

10-60 Hz

RthSA100% Load Continuous

10-60 Hz

PWM Frequency (kHz)

Thermal Resistance (RthSA ¡C/W)

Total Power Dissipation (Watts)

RthSA150% Load (1 min.)

Downto 3 Hz

3hp

(2.2 kW)

page 7

IRPT2051

Mounting, Hookup and Application Instructions

Mounting

1. Remove all particles and grit from the heat sink and power

substrate.

2. Spread a .004" to .005" layer of silicone grease on the heat

sink, covering the entire area that the power substrate will oc-

cupy. Recommended heat sink flatness is .001 inch/inch and

Total Indicator Readout (TIR) of .003" below substrate.

3. Place the power substrate onto the heat sink with the

mounting holes aligned and press it firmly into the silicone

grease.

4. Place the 2 M4 mounting screws through the PCB and

power module and into the heat sink and tighten the screws to

1 Nm torque.

Control Connections

All input and output connections are made via a 16-terminal fe-

male connector to J6.

Figure 6. Power Assembly Mounting Screw Sequence

1234567890123456789012345678901212

23456789012345678901234567890121

1234567890123456789012345678901212

1 2

Power Connections

3-phase input connections are made to terminals R, S and T (J1).

Inverter output terminal connections are made to terminals U, V

and W (J7).

Positive DC bus and Brake IGBT collector connections are

brought out to terminals P (positive) and BR (brake) of J5 con-

nector. An external resistor for braking can be connected across

these terminals.

Power-Up Procedure

When 3-phase input power is first switched on, PWM inputs to

the IRPT2051 must be inhibited (held high) until the protection

latch circuitry is reset. To reset this latch before inverter start-

up, RESET pin on J6 connector must be pulled down low for at

least 2 µsec. This will set the FAULT feedback signal high.

Now, the PWM input signals can be applied for inverter start-up.

Power-Down Procedure

The following sequence is recommended for normal power

down:

1. reduce motor speed by PWM control

2. inhibit PWM inputs

3. disconnect main power.

Figure 7a. Control Signal Connector Figure 7b. Input and Output Terminal Blocks

page 8

IRPT2051

IRPT2051D Mechanical Specifications

NOTE: Dimensions are in inches (millimeters)

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IRPT2051

IRPT2015A Mechanical Specifications

NOTE: Dimensions are in inches (millimeters)

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IRPT2051

IRPT2051A Power Assembly

Chip and wire epoxy encapsulated module with 1600V input

rectifiers, 1200V brake IGBT and freewheeling diode, 1200V

short-circuit rated, ultra-fast IGBT inverter with ultra-fast free-

wheeling diodes, temperatures sensing NTC thermistor and

current sensing low-inductance shunts.

IRPT2051C Complete

IRPT2051A Power Module and IRPT2051D Driver-Plus

Board pre-assembled and tested toeet all system specifications.

IRPT2051D Driver-

Plus

Board

Printed circuit board assembled with DC link capacitors, NTC

in-rush limiting thermistor, high-power terminal blocks, surge

suppression MOVs, IGBT gate drivers, protection circuitry and

low power supply. The PCB is functionally tested with standard

power module to meet all system specifications.

IRPT2051E Design Kit

Complete

(IRPT2051C) with full set of de-

sign documentation including schematic diagram, bill of

material, mechanical layout, schematic file, Gerber files and

design tips.

Part Number Identification and Ordering Instructions

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IRPT2051

Functional Information

CAUTION:All control logic is referenced to the negative power bus,

which is live with respect to earth/ground.

Capacitor Soft Charge

A dc bus capacitor is connected to the rectifier bridge output

through an NTC. At power-up, the NTC limits the maximum

inrush current to the rated peak input current, though normal line

impedance will impact the inrush insignificantly. During normal

operation, current through the NTC reduces its resistance, hence

reducing its losses. In the event of a brief power loss, the NTC

will not limit the recharge of the bus because its temperature will

not have time to reduce back to ambient.

System Power Supply

A buck converter designed with the IR2152 self-oscillating

half-bridge driver generates VCC (15V) and VD (5V) for drive

and protection circuits. It draws its power from the midpoint of

the dc bus, which si regulated to half of the voltage. Both VCC

and VD are available at the control connector toupply micropro-

cessor controls. Rated output current is the sum of ICC and ID.

Floating power supplies for high side devices are derived

through the bootstrap technique, simplifying power supply re-

quirements.

Gate Drive Circuits

Gate drive for the inverter is implemented with an IR2233

monolithig 3-phase HVIC driver. An under voltage circuit

monitors the local power supply voltage. It will set the FAULT

and inhibit the PWM output in the event of a low power condi-

tion to protect the IGBTs from excessive power loss due to low

gate drive.

A short circuit buffer power supply counters the voltage drop

across the shunt in the negative dc bus, allowing the device to

have nominal gate voltage during short circuit. This will main-

tain the current to a detectable level.

The brake IGBT is generally switched at low frequency, so a

simple bipolar gate drive circuit is used to drive it.

System Protections

Short circuit is monitored through a shunt in the negative

bus, which detects phase-to-phase and phase-to-earth short cir-

cuits (when current flows from earth to negative bus). The

voltage drop across teh shunt is compared to a pre-set limit and

when the current exceeds the rated nominal value, this protection

is activated. The shunt signal is available to the user on the con-

trol interface as IFB. Since this is the same node that is used by

this protection circuit, any external connection should be done

through a high impedance buffer stage.

Earth/ground fault from positive bus to earth is detected to

the shunt in the positive bus and an opto-coupler. When fault

current exceeds the rated nominal value, this protection is acti-

vated.

Over temperature is measured by a thermistor mounted

close to the inverter section in the power module. When the sub-

strate temperature exceeds the nominal rated temperature, this

protection is activated.

Over voltage is detected by comparing attenuated dc bus

voltage with a pre-set reference. When the bus voltage exceeds

the nominal rated value, this protection is activated. The attenu-

ated dc bus voltage is available to the user on the control

interface as VFB. Since this is the same node that is compared to

the reference, any external connections should be done through a

high impedance buffer stage.

If any of the protection features are activated, the TRIP signal

goes high activating the internal latch of the IR2233. This turns

off all gate outputs to the inverter and acknowledges the FAULT

to the controller.

Trip Reset

The FAULT signal can be removed by pulling down the RE-

SET pin for 2 µs. This should be done only after all inputs,

IN1...IN6, are inactive. The system protections cannot be dis-

abled by tying this pin to N because the fault logic takes

precedence over the reset.

page 12

IRPT2051

WORLD HEADQUARTERS: 233 Kansas St., El Segundo, California 90245, Tel: (310) 322 3331

EUROPEAN HEADQUARTERS: Hurst Green, Oxted, Surrey RH8 9BB, UK Tel: ++ 44 1883 732020

IR CANADA: 7321 Victoria Park Ave., Suite 201, Markham, Ontario L3R 2Z8, Tel: (905) 475 1897

IR GERMANY: Saalburgstrasse 157, 61350 Bad Homburg Tel: ++ 49 6172 96590

IR ITALY: Via Liguria 49, 10071 Borgaro, Torino Tel: ++ 39 11 451 0111

IR FAR EAST: 171 (K&H Bldg.), 3-30-4 Nishi-ikebukuro 3-Chome, Toshima-ku, Tokyo Japan Tel: 81 3 3983 0086

IR SOUTHEAST ASIA: 315 Outram Road, #10-02 Tan Boon Liat Building, Singapore 0316 Tel: 65 221 8371

http://www.irf.com/ Data and specifications subject to change without notice. 5/97

Interface With System Controller

All signals are referred to the negative dc bus (N). IN1...IN7

are TTL/CMOS compatible active low signals. Maximum volt-

age rating for these signals is 5V. All channels are provided

with pull-up resistors and can be used with open collector inputs.

FAULT is an open drain, active low signal, provided with a

pull-up and a red LED. Typical current sink capacity for this pin

is 5 mA. This pin should not be directly connected to an npn

transistor base as it would appear to always be in FAULT mode.

VFB and IFB are the scaled down dc bus voltage and bus cur-

rent respectively. The on-board protection circuitry use these

signals for sensing fault conditions. Any connection to these

signals should be done through a high impedance buffer stag so

as not to disrupt the protection circuits.

Heat Sink Requirements

Figures 5a and 5b (page 6) show the thermal resistance of the

heat sink required for various output power levels and PWM

switching frequencies. Maximum total losses of the unit are also

shown.

This data assumes the following key operating conditions:

•The maximum continuous combined losses of the rectifier

and inverter occur at full pulse with modulation. These

losses set the maximum continuous operatiing temperature

of the heat sink.

•The maximum combined losses of the rectifier and inverter

at full PWM under overload set the incremental tempera-

ture rise of the heat sink during overload, which is limited

to 10°C due to ZTHSA.

•The minimum output frequency at which full overload cur-

rent is to be delivered sets the peak IGB junction

temperatures.

•At low output frequency IGBT junction temperatures tends

to follow the instantaneous fluctuations of the output cur-

rent. Thus, peak junction temperature rise increases as

output frequency decreases.

Voltage Rise During Braking

The motor will feed energy back to the DC link during elec-

tric braking, forcing DC bus voltage to rise above the level

defined by input line voltage. Deceleration of the motor must be

controlled by appropriate PWM control to keep the DC bus volt-

age within the rated maximum vaue. For high inertial loads, or

for very fast deceleration rates, this can be achieved by the brake

provided in the system by connecting an external braking resis-

tor between terminals P and BR. IN7 controls the brake

transistor swtiching.