Altera Multiaxis Motor Control Board User Manual

Multiaxis Motor Control Board

MNL-1073 Reference Manual

This reference manual describes the Altera® Multiaxis Motor Control Board.

Efficient control of torque and speed of AC motors requires corresponding control of
voltage and frequency that you supply to the motor. Typically, you filter the AC input
voltage for electromagnetic interference (EMI), correct it to achieve unity power
factor, then rectify it to yield a DC voltage. You then invert the rectifier output again
through switching of power electronics, such as insulated-gate bipolar transistors
(IGBTs) to create the appropriate variable AC voltages and frequency for the motor.
Control algorithms such as Field Oriented Control (FOC) of PMSMs require you to
measure and analog to digitally A/D convert motor current and voltages, to provide
the required feedback to the controller. In addition, you use analog-to-digital
converters (ADCs ) to monitor the DC link voltage and current. Multiaxis drives
achieve either a high degree of coordination of control across motors or, in some
applications, integrate control of multiple independent motors to reduce overall
system cost. In closed-loop control systems, modern drive requirements continue to
evolve the need for higher precision position and velocity encoder feedback devices.
Standard encoder interfaces, 7such as EnDat, BiSS, and HiperFace, are based on
traditional sin and cosine encoder techniques. These encoder interfaces incorporate
communication controllers that can transmit information back to the drive digitally,
which enhances their performance in noisy environments. Encoder interfaces support
features, such as online inspection of motor parameters and line delay measurement,
which you can incorporate into the motor control algorithm.

Features

101 Innovation Drive
San Jose, CA 95134

www.altera.com

The Multiaxis Motor Control Board contains all the power electronics, current and
voltage sensing, and connections for motor position feedback. You can use the motor
Control Board to develop a motor control system that supports permanent magnet
synchronous motors (PMSMs) or brushless DC (BLDC) motors. The Multiaxis Motor
Control Board is suitable for single-axis and multiaxis motor control applications and
supports multiple position feedback interfaces..

The Multiaxis Motor Control Board has the following features:

■ Power factor correction (PFC) and EMI filter

■ DC link power supply of 400 V

■ Switch mode power supplies for logic

■ IGBT power stages

■ Sigma-delta ADCs for sensing voltages and currents

■ Brake (chopper) switch

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Page 2 Setting Up the Multiaxis Motor Control Board

■ Position feedback interfaces for:

■ EnDat

■ Bidirectional synchronous serial (BiSS)

■ HIPERFACE

■ Resolver

■ Quadrature

■ Hall effect

Setting Up the Multiaxis Motor Control Board

w The Multiaxis Motor Control Board operates at high voltages and currents that can

result in hazardous electrical shock. Ensure you understand and follow all necessary
safety precautions before you operate the board.

Altera supplies the Multiaxis Motor Control Board configured for EnDat interfaces, to
change these settings, perform the following steps:

1. Use the jumpers to select the encoder power supply.

2. Use the jumpers to configure the encoder RS485.

3. Configure the Multiaxis Motor Control Board to match the interface type that the
host board implements, otherwise unexpected damage may occur.

Connecting Encoders

To connect the EnDat encoder and motor, perform the following steps:

1. Consult the data sheet for your encoder and set the encoder power supply
jumpers to generate the required supply voltage (Ta bl e 1 0).

2. Set the DRV_x_SER_DATA jumpers for bidirectional signalling on the RX pair for
the channel you intend to use (Tab le 1 2)

3. Use the 20-way terminal block to connect each encoder. Ta ble 1 lists the four
terminal blocks.

Table 1. Encoder terminal Blocks

Channel Encoder Terminal Block

0J9

1J23

2J37

3J51

Multiaxis Motor Control Board February 2014 Altera Corporation

Setting Up the Multiaxis Motor Control Board Page 3

4. Connect the encoder cable to the screw terminal on the relevant terminal block for
channel you intend to use (Tab le 2 ).

Table 2. Screw Terminal Connections for BiSS and EnDat Encoders

Signal Name

Data+

Data-

Clock+

Clock-

Power

Ground

Connecting the Motors

To prevent electrical shocks before connecting or disconnecting the motor:

1. Always shut down the motor control application on the host board.

2. Disconnect the Multiaxis Motor Control Board from the mains supply.

3. Ensure the DC link capacitors are discharged.

4. Use the four-way screw terminal block to connect each motor. Ta bl e 3 lists motor
connectors.

Table 3. Motor Connectors

Cable Color

BiSS EnDat

PInk Grey 18

Grey Pink 19

Yellow Violet 14

Green Yellow 15

White Blue and brown/green 1

Brown White and white/green 20

Screw Terminal

(J9, J23, J37, J51)

Channel Motor Connector

0J2

1J16

2J30

3J44

5. Connect the motor to the screw terminal connector for the channel you intend to
use (Tab le 6 ).

Multiaxis Motor Control BoardFebruary 2014 Altera Corporation

Page 4 Functional Description

Functional Description

Figure 1 shows the Multiaxis Motor Control Board.

Figure 1. Multiaxis Motor Control Board

Multiaxis Motor Control Board February 2014 Altera Corporation

Functional Description Page 5

Isolated

22-V Supply

Low-Voltage

Logic Supplies

400-V

DC Link

Bootstrap

Circuit

IGBTs

x4 Channel

Encoder
Interface

Current and

Voltage

Sensing

Ballast/

Brake

Mains

Input

Digital I/O Isolators

HSMC

Motors

Encoders

Figure 2 shows a high-level block diagram of the Multiaxis Motor Control Board.

Figure 2. Block Diagram

The following sections describe the functional blocks.

Digital I/O Isolators

Analog Devices ADuM1401 digital isolators isolate all digital I/O signals on the
Multiaxis Motor Control Board. They provide complete electrical isolation between
the host FPGA board and the power electronics on the Multiaxis Motor Control
Board. In some circuit locations, the board uses Silicon Labs Si8440 or Si8441 digital
isolators for their output behavior during power down, to prevent transient control
signals on the IGBT drivers.

One side of each isolator connects to the HSMC connector and takes power from the
HSMC connector. The other side of each isolator takes power from an isolated power
supply on the Multiaxis Motor Control Board.

Power Supplies

The Multiaxis Motor Control Board converts mains input to the DC link and a number
of lower voltages for logic and interfacing.

Multiaxis Motor Control BoardFebruary 2014 Altera Corporation

Page 6 Functional Description

PFC

Bus

Converter

EMI

Filter

~~+

_

400 V at 4 A

22 V at 1A

90 - 240 VAC

50/60 Hz

Emerson

400-V PFC

Module

Isolated

SD-ADC

20 MSPS

3.3 V

3.3 V

400 V at 4 A

Emerson

400-V PFC

Module

Isolated

SD-ADC

20 MSPS

Mains Input

The Multiaxis Motor Control Board filters the mains input (Figure 3) and then splits to
the DC link and the 22-V power supply. Both power supplies incorporate PFC. The
Multiaxis Motor Control Board works with mains input voltages of 85 to 264 VAC, 50
or 60 Hz. The mains input includes an EMI filter.

Figure 3. Mains Input Filtering

DC Link and PFC

To provide unity power factor with very low-level harmonic distortion in line current,
an Emerson AIF04ZPFC-01L module produces the 400-V DC link voltage (Figure 4).
The PFC works over all typical line voltages used worldwide.

Figure 4. DC Link Voltage PFC Supply

Multiaxis Motor Control Board February 2014 Altera Corporation

Functional Description Page 7

The DC link can supply up to 1.5 kW in total, across all four motor channels with a
mains input of 240 V. At lower mains voltages, the Multiaxis Motor Control Board
reduces the maximum power. For example, 1 kW at 110 V input. Isolated sigma-delta
ADCs allow you to monitor the DC link voltage and current.

Isolated 22 V Supply

A Linear Technology LT3798 provides an isolated 22-V supply that feeds further
switch mode regulators to generate all of the required voltages on the Multiaxis Motor
Control Board.

15 V IGBT Gate Drive Supply

Two Linear Technology LTC3631EDD#PBF generate the 15-V supplies that the IGBT
modules require. One LTC361 supplies motor channels 0 and 1; the other one supplies
motor channels 2 and 3.

3.3 V and 5 V Logic Supplies

The 3.3-V and 5-V supplies for logic devices both use Linear Technology LTM8022
DC/DC micromodules.

Brake

3.3 V Isolator Supply

The isolators connected to the HSMC connector can receive power directly from the
HSMC 3.3-V pins or from the HSMC 12-V pin via a Linear Technology LTM8022
micromodule switch mode power supply.

Encoder Power Supplies

Each motor channel includes a power supply (LTM8025 micromodule) for the
encoder interface that you can configure for 3.3 V, 5 V, or 12 V as required by the
encoder.

The Multiaxis Motor Control Board includes incorporates a brake circuit with a
Fairchild FAN3111E gate driver, Fairchild FGP15N60 IGBT, and 100-Ohm brake
resistor.

During braking, the kinetic energy of the motor feeds back into the DC link circuit as
extra stored energy in the DC link capacitor. You can turn on the brake resistor to
dissipate excess energy and prevent the DC link voltage from rising too high.

The peak power dissipation in the brake resistor is:

2

V

/R = V

As the brake resistor is rated for only 20 W continuous power dissipation, only use it
for only a few milliseconds. The gate drive to the brake circuit is AC coupled.The
FPGA must drive a square wave on the
A steady signal, either high or low, results in the Power Supply turning off the brake.
Furthermore, the FPGA should implement some form of time out to prevent you from
activating the brake for too long.

DCLINK

2

/100 = 1.6 kW

HSMC_MOTOR_BRAKE

signal to activate the brake.

Multiaxis Motor Control BoardFebruary 2014 Altera Corporation