This design includes an Infolytica-MotorSolve generated Permanent Magnet Synchronous Machine (PMSM) model and a PWM Drive circuit. The drive includes a D-Q control algorithm, and uses space-vector modulation (SVM) to generate the digital PWM signals to the switches of the bridge.

The mechanical load includes static and kinetic friction. The steering torque applied by the driver is assisted by torque from the motor, with a non-linear gain profile as specified in the "torque_assist_table" function.

In a companion version of this design, "Power Steering System with MotorSolve Generated PMSM Model", Clarke and Park Transform models are used with a continuous ideal voltage drive. This shows the ability to develop motor controls and drives at the abstract level and also at the circuit level.

This Electric Power Steering (EPS) System design includes a MotorSolve generated Permanent Magnet Synchronous Machine (PMSM) model and a PWM Drive circuit. The drive includes a D-Q control algorithm, and uses space-vector modulation (SVM) to generate the digital PWM signals to the switches of the bridge.

The mechanical load model includes static and kinetic friction, a steering force that varies with rack displacement, as well as various mass, inertia, damping and spring/stiffness elements of the steering system. The steering torque, applied by the vehicle's driver, is assisted by torque from the motor scaled by the gear ratio. For the control, a non-linear gain profile is specified in the "torque_assist_table" function, and a lead-lag compensator is used to improve system stability.

In a companion version of this design, "EPS System with MotorSolve Generated PMSM Model and Ideal Drive", Clarke and Park Transform models are used with a continuous ideal voltage drive. This shows the ability to develop motor controls and drives at the abstract level and also at the circuit level.

FOC

Buck P-MOSFET(Aufwärtswandler)

www.ebookaktiv.de

This example shows a more detailed circuit- and logic-level implementation of the PID Control Loop shown in the companion example, “PID Speed Control Loop – Continuous”. The ideal motor drive block of the “Continuous” version is expanded here, to include both a H-bridge motor drive, and also the digital logic necessary for converting the continuous PID controller output into the desired PWM signals that are distributed to drive the gates of the power MOSFET switches. The MOSFET model was calibrated to represent an IRF3710, using only information published on the manufacturer’s datasheet.

The rest of the system, including the PID block-diagram controller, the mechanical fan load and the DC Motor characterized to represent an FRC (First Robotics Competition) CIM Motor, are the same as in the Continuous version. While the simulation time for this switching version is significantly longer, more detailed information about practical circuit performance and component sizing is available. For example, the fan speed step response is somewhat different from the conceptual design, because of the losses in the MOSFETs under high current conditions, as well as voltage drop in the battery. Also, information regarding component stress levels within the “datasheet specified” MOSFETs and Diodes is provided.

Kennlinie DC-Motor

Kennlinie DC-Motor

Power PWM driver with voltage controlled current source for driving/suppling pulse transformer.

Pulse transformer parameters:

1. INPUT COIL:

1.1. fi wire enamelled winding = 0,35 mm (from pulse transformer datasheet)

1.2. wire enamelled winding length = 0,400 m = 400 mm (calculated)

1.3. N = 2 x 12 scrolls (from pulse transformer datasheet)

1.4. R = 0,11 Ohms (parallel 2 x 0,22 Ohms) (measured and/equal calculated

1.5. H = 47,52 uH (from pulse transformer datasheet)

1.6. U = 3,5 - 15 V DC (from pulse transformer datasheet)

2. OUTPUT COIL:

2.1. fi wire enamelled winding = 0,15 mm (from pulse transformer datasheet)

2.2. N = 1 x 300 scrolls (from pulse transformer datasheet)

2.3. R = 10,6 Ohms (measured)

2.4. U = 400 V DC (after diode one-half rectifier and C filter) (from pulse transformer datasheet)

3. OTHER

3.1. voltage insulation test at 1 kV (from pulse transformer datasheet)

3.2. dedicated frequency 33 kHz (from pulse transformer datasheet)

3.3. recommended driver IC ON Semiconductor MC34063 (1.5 A, Step-Up/Down/Inverting Switching Regulators) (from pulse transformer datasheet)

Parameters to reach:

1. PWM frequency: from 1 kHz to 75/100 kHz

2. PWM Duty Cycle: from 5 % to 95 %

3. Current: from 5/10 mA DC to 1000/2000 mA DC

4. PWM control voltage: from 0 V DC to 3.0 V DC or from 0 V DC to 3.3 V DC (whatever for now)

5. Current source voltage: from 0.1 V DC to +3.3/5.0 V DC

Permanent Magnet Synchronous Machine (PMSM) and Ideal (continuous) Drive circuit, with mechanical load. The drive includes a D-Q control algorithm.

In a companion version of this design, "PMSM Motor And PWM Drive", the same motor control algorithm is used but SVM (space vector modulation) provides PWM switching signals to ideal switches in an actual 3-phase inverter implementation.